Endovascular Aneurysm Repair Devices as a Use Case for Postmarketing Surveillance of Medical Devices

Importance

The US Food and Drug Administration (FDA) is building a national postmarketing surveillance system for medical devices, moving to a "total product life cycle" approach whereby more limited premarketing data are balanced with postmarketing surveillance to capture rare adverse events and long-term safety issues.

Objective

To assess the methodological requirements and feasibility of postmarketing device surveillance using endovascular aneurysm repair devices (EVARs), which have been the subject of safety concerns, using clinical data from a large health care system.

Design, Setting, and Participants

This retrospective cohort study included patients with electronic health record (EHR) data in the Veterans Affairs Corporate Data Warehouse.

Exposure

Implantation of an AFX Endovascular AAA System (AFX) device (any of 3 iterations) or a non-AFX comparator EVAR device from January 1, 2011, to December 21, 2021.

Main Outcomes and Measures

The primary outcomes were rates of type III endoleaks and all-cause mortality; and rates of these outcomes associated with AFX devices compared with non-AFX devices, assessed using Cox proportional hazards regression models and doubly robust causal modeling. Information on type III endoleaks was available only as free-text mentions in clinical notes, while all-cause mortality data could be extracted using structured data. Device-specific information required by the FDA is ascertained using unique device identifiers (UDIs), which include factors such as model numbers, catalog numbers, and manufacturer-specific product codes. The availability of UDIs in EHRs was assessed.

Results

In total, 13 941 patients (mean [SD] age, 71.8 [7.4] years) received 1 of the devices of interest (AFX with Strata [AFX-S]: 718 patients [5.2%]; AFX with Duraply [AFX-D]: 404 patients [2.9%]; or AFX2: 682 patients [4.9%]), and 12 137 (87.1%) received non-AFX devices. The UDIs were not recorded in the EHR for any patient with an AFX device, and partial UDIs were available for 19 patients (0.1%) with a non-AFX device. This necessitated the development of advanced natural language processing tools to define the cohort of patients for analysis. The study identified a significantly higher risk of type III endoleaks at 5 years among patients receiving any of the AFX device iterations, including the most recent version, AFX2 (11.6%; 95% CI, 8.1%-15.1%) compared with that among patients with non-AFX devices (5.7%; 95% CI, 2.2%-9.2%; absolute risk difference, 5.9%; 95% CI, 2.3%-9.4%). However, there was no significantly higher all-cause mortality for any of the AFX device iterations, including for AFX2 (19.0%; 95% CI, 16.0%-22.0%) compared with non-AFX devices (18.0%; 95% CI, 15.0%-21.0%; absolute risk difference, 1.0%; 95% CI, -2.1% to 4.1%).

Conclusions and Relevance

The findings of this cohort study suggest that clinical data can be used for the postmarketing device surveillance required by the FDA. The study also highlights ongoing challenges to performing larger-scale surveillance, including lack of consistent use of UDIs and insufficient relevant structured data to efficiently capture certain outcomes of interest.

Evaluation of the prognostic value of computed tomography-derived body composition in patients undergoing endovascular aneurysm repair

BACKGROUND

Endovascular aneurysm repair (EVAR) is the most common mode of repair of abdominal aortic aneurysms (AAA) in the UK. EVAR ranges from standard infrarenal repair to complex fenestrated and branched EVAR (F/B-EVAR). Sarcopenia is defined by lower muscle mass and function, which is associated with inferior perioperative outcomes. Computed tomography-derived body composition analysis offers prognostic value in patients with cancer. Several authors have evaluated the role of body composition analysis in predicting outcomes in patients undergoing EVAR; however, the evidence base is limited by heterogeneous methodology.

METHODS

Six hundred seventy-four consecutive patients (58 (8.6%) female, mean (SD) age 74.4 (6.8) years) undergoing EVAR and F/B-EVAR at three large tertiary centres were retrospectively recruited. Subcutaneous and visceral fat indices (SFI and VFI), psoas and skeletal muscle indices, and skeletal muscle density were measured at the L3 vertebral level from pre-operative computed tomographies. The maximally selected rank statistic technique was used to define optimal thresholds to predict mortality.

RESULTS

There were 191 deaths during the median follow-up period of 60.0 months. Mean (95% CI) survival in the low SMI versus high SMI subgroups was 62.6 (58.5-66.7) versus 82.0 (78.7-85.3) months (P < 0.001). Mean (95% CI) survival in the low SFI versus high SFI subgroups was 56.4 (48.2-64.7) versus 77.1 (74.2-80.1) months (P < 0.001). One-year mortality in the low SMI versus high SMI subgroups was 10% versus 3% (P < 0.001). Low SMI was associated with increased odds of one-year mortality (OR 3.19, 95% CI 1.60-6.34, P < 0.001). Five-year mortality in the low SMI versus high SMI subgroups was 55% versus 28% (P < 0.001). Low SMI was associated with increased odds of five-year mortality (OR 1.54, 95% CI 1.11-2.14, P < 0.01). On multivariate analysis of all patients, low SFI (HR 1.90, 95% CI 1.30-2.76, P < 0.001) and low SMI (HR 1.88, 95% CI 1.34-2.63, P < 0.001) were associated with poorer survival. On multivariate analysis of asymptomatic AAA patients, low SFI (HR 1.54, 95% CI 1.01-2.35, P < 0.05) and low SMI (HR 1.71, 95% CI 1.20-2.42, P < 0.01) were associated with poorer survival.

CONCLUSIONS

Low SMI and SFI are associated with poorer long-term survival following EVAR and F/B-EVAR. The relationship between body composition and prognosis requires further evaluation, and external validation of the thresholds proposed in patients with AAA is required.

A meta-analysis of safety and efficacy of endovascular aneurysm repair in aneurysm patients with severe angulated infrarenal neck

Objectives

A growing number of abdominal aortic aneurysms with severe angulated neck anatomy is treated by endovascular means. However, contradictory early and late outcomes have been reported. Our review and outcome analysis attempted to evaluate the available literature and provide clinicians with a base for clinical implementation and future research.

Materials and methods

A systematic review of the literature was undertaken to identify the outcomes of endovascular aneurysm repair in patients with severe infrarenal neck angulation (SNA ≥ 60°) vs non-severe neck angulation (NSNA). Outcome measures included perioperative complications, type 1a endoleak, neck-related secondary procedures, stent graft migration, aneurysm rupture, increase (>5mm) in sac diameter, all-cause and aneurysm-related mortality (PROSPERO Nr.: CRD42021233253).

Results

Six observational studies reporting on 5981 patients (1457 with SNA and 4524 with NSNA) with a weighted mean follow-up period of 1.8 years were included. EVAR in SNA compared with NSNA was associated with a higher rate of type 1a endoleak at 30 days (4.0% vs 1.8%; p< 0.00001), at 1 year (2.8% vs 1.9%; p<0.03), at 2 years (4.9% vs 2.1%; p< 0.0002), at 3 years (5.6% vs 2.6%; p< 0.0001). The rate of neck-related secondary procedures was significantly higher at 1 year (6.6% vs 3.9%; p<0.05) and at 3 years (13.1% vs 9%; p<0.05). Graft migration, aneurysm sack increase, aneurysm rupture and all-cause mortality were not statistically different at mid-term.

Conclusions

The use of EVAR in severely angulated infrarenal aortic necks is associated with a high rate of early and mid-term complications. However, aortic related and all-causes mortality are not higher compared to patients with NSNA. Therefore, EVAR should be cautiously used in patients with SNA.

Reliability of hospital-level mortality in abdominal aortic aneurysm repair

OBJECTIVE

The relationship between volume and surgical outcomes has been shown for a variety of surgical procedures. The effects in abdominal aortic aneurysm repair have continued to be debated. Reliability adjustment has been used as a method to remove statistical noise from hospital-level outcomes. However, its impact on aortic aneurysm repair is not well understood.

METHODS

We used prospectively collected data from the Vascular Quality Initiative to identify all patients who had undergone abdominal aortic aneurysm repair from 2003 to 2019. We first calculated the hospital-level risk-adjusted 30-day mortality rates. We subsequently used hierarchical logistic regression modeling to adjust for measurement reliability using empirical Bayes techniques. The effect of volume on risk- and reliability-adjusted mortality rates was then assessed using linear regression.

RESULTS

Between 2003 and 2019, 67,073 abdominal aortic aneurysms were repaired, of which 11,601 (17.3%) were repaired with an open approach. The median annual volume was 7.4 (interquartile range, 3.0-13.3) for open repairs and 35.4 (interquartile range, 18.8-59.8) for endovascular repairs. Of the 223 hospitals that had performed open repairs during the study period, only 11 (4.9%) had performed ≥15 open repairs annually, and the risk-adjusted mortality rates varied from 0% to 75% across all centers. After reliability adjustment, the variability of the risk-adjusted mortality rates had decreased significantly to 1.3% to 8.2%. The endovascular repair risk-adjusted mortality rate variability had decreased from 0% to 14.3% to 0.3% to 2.8% after reliability adjustment. A decreasing trend in mortality was found with increasing an annual case volume for open repair with each additional annual case associated with a 0.012% decrease in mortality (P = .05); however, the relationship was not significant for endovascular repair (P = .793).

CONCLUSIONS

We found that most hospitals do not perform a sufficient number of annual cases to generate a reliable center-specific mortality rate for open aneurysm repair. Center-specific mortality rates for low-volume centers should be viewed with caution, because a substantial proportion of the variation for these outcomes will be statistical noise rather than true center-level differences in the quality of care.

Outcomes after Elective Open Abdominal Aortic Aneurysm Repair in Octogenarians Compared to Younger Patients in Korea

BACKGROUND

Although the first choice of treatment for abdominal aortic aneurysm (AAA) is endovascular aneurysm repair, especially in elderly patients, some patients require open surgical repair. The purpose of this study was to compare the mortality outcomes of open AAA repair between octogenarians and younger counterparts and to identify the risk factors associated with mortality.

METHODS

All consecutive patients who underwent elective open AAA repair due to degenerative etiology at a single tertiary medical center between 1996 and June 2020 were included in this retrospective review. Medical records and imaging studies were reviewed to collect the following information: demographics, comorbid medical conditions, clinical presentations, radiologic findings, surgical details, and morbidity and mortality rates. For analysis, patients were divided into two groups: older and younger than 80 years of age. Multivariate analysis was performed to identify factors associated with mortality after elective open AAA repair.

RESULTS

Among a total of 650 patients who underwent elective open AAA repair due to degenerative AAA during the study period, 58 (8.9%) were octogenarians and 595 (91.1%) were non-octogenarians. Patients in the octogenarian group were predominantly female and more likely to have lower body weight and body mass index (BMI), hypertension, chronic kidney disease, and lower preoperative serum hemoglobin and albumin compared with patients in the non-octogenarian group. Maximal aneurysm diameter was larger in octogenarians. During the median follow-up duration of 34.4 months for 650 patients, the median length of total hospital and intensive care unit stay was longer in octogenarians. The 30-day (1.7% vs. 0.7%, P = 0.374) and 1-year (6.9% vs. 2.9%, P = 0.108) mortality rates were not statistically significantly different between the two groups. Multivariate analysis showed that low BMI was associated with increased 30-day (odds ratio [OR], 16.339; 95% confidence interval [CI], 1.192-224.052; P = 0.037) and 1-year (OR, 8.236; CI, 2.301-29.477; P = 0.001) mortality in all patients.

CONCLUSION

Because the mortality rate of octogenarians after elective open AAA repair was not significantly different compared with their younger counterparts, being elderly is not a contraindication for open AAA repair. Low BMI might be associated with increased postoperative mortality.

Insulin resistance and risk of vascular events, interventions and mortality in type 1 diabetes

OBJECTIVE

To identify determinants associated with insulin resistance and to assess the association between insulin resistance and cardiovascular events, vascular interventions and mortality in people with type 1 diabetes at high risk of cardiovascular disease.

DESIGN

Prospective cohort study.

METHODS

One hundred and ninety-five people with type 1 diabetes from the Secondary Manifestations of ARTerial disease (SMART) cohort were included. Insulin resistance was quantified by the estimated glucose disposal rate (eGDR) with higher eGDR levels indicating higher insulin sensitivity (i.e. lower eGDR levels indicating higher insulin resistance). Linear regression models were used to evaluate determinants associated with eGDR. The effect of eGDR on cardiovascular events, cardiovascular events or vascular interventions (combined endpoint) and on all-cause mortality was analysed using Cox proportional hazards models adjusted for confounders.

RESULTS

In 195 individuals (median follow-up 12.9 years, IQR 6.7-17.0), a total of 25 cardiovascular events, 26 vascular interventions and 27 deaths were observed. High eGDR as a marker for preserved insulin sensitivity was independently associated with a lower risk of cardiovascular events (HR: 0.75; 95% CI: 0.61-0.91), a lower risk of cardiovascular events and vascular interventions (HR: 0.74; 95% CI: 0.63-0.87) and a lower risk of all-cause mortality (HR: 0.81; 95% CI: 0.67-0.98).

CONCLUSIONS

Insulin resistance as measured by eGDR is an additional risk factor for cardiovascular disease in individuals with type 1 diabetes. Modification of insulin resistance by lifestyle interventions or pharmacological treatment could be a viable therapeutic target to lower the risk of cardiovascular disease.

Incidence, predictive factors, and outcomes of intraprocedure adverse events during fenestrated-branched endovascular aortic repair of complex abdominal and thoracoabdominal aortic aneurysms

OBJECTIVE

To evaluate the incidence of intraoperative adverse events (IAEs) and their impact on outcomes after fenestrated-branched endovascular aortic repair (FB-EVAR) of complex abdominal aortic aneurysms and thoracoabdominal aortic aneurysm (TAAAs).

METHODS

We reviewed the clinical and imaging data of 600 consecutive patients (445 males; mean age, 75 ± 8 years) who underwent FB-EVAR between 2007 and 2019 in a single institution. IAE was defined as any intraoperative complication or technical problem requiring additional and unplanned procedures, and was classified as access-related, target artery (TA)-related, or graft-related. End points included rates of IAEs, 30-day or in-hospital mortality, major adverse events, patient survival, freedom from secondary intervention, and TA instability.

RESULTS

A total of 122 IAEs were identified in 105 patients (18%). IAEs were TA-related in 55 patients (9%), access-related in 46 patients (8%), and graft-related in seven patients (1%). Female sex was more frequent among patients with IAEs (44% vs 22%; P < .001). Patients with IAEs had smaller renal artery diameter (-0.4 mm, 5.4 ± 0.8 mm vs 5.8 ± 0.9 mm; P < .001), and were treated more often for TAAAs (72% vs 54%; P < .03). Technical success was achieved in 96.5% of patients and was lower for patients with IAEs (82% vs 99%; P < .001). Major adverse events were significantly more frequent among patients who had IAEs (odds ratio [OR], 1.98; 95% confidence interval [CI], 1.21-3.25), most due to acute kidney injury (27% vs 11%; P < .001) including new-onset dialysis (5% vs 1%; P = .01). On multivariate logistic regression model, female sex (OR, 2.5; 95% CI, 1.5-4.0), TA stenosis >50% (OR, 2.0; 95% CI, 1.3-3.3), and Crawford Extent II TAAA (OR, 1.9; 95% CI, 1.1-3.3) were predictive of IAEs, whereas preloaded design (OR, 0.6; 95% CI, 0.4-0.9) and TA diameter (+1 mm; OR, 0.6; 95% CI, 0.4-0.9) were protective of IAEs. IAEs negatively affected secondary intervention (hazard ratio [HR], 1.6; 95% CI, 1.1-2.3) and TA instability (HR, 2.5; 95% CI, 1.2-5.4); however, IAEs did not affect patient survival (HR, 1.0; 95% CI, 0.7-1.4).

CONCLUSIONS

IAEs are common, occurring in nearly one of five patients treated with FB-EVAR for complex aortic aneurysms, and have a negative impact on clinical outcomes. IAEs were associated with female sex, TA diameter, and more extensive aortic disease.

Early Postoperative Mortality Among US Veterans With a Robust Physiologic Reserve Undergoing Open or Endovascular Abdominal Aortic Aneurysm Repair

This cohort study uses data from the Veterans Affairs Surgical Quality Improvement Program database to examine the risk of early postoperative mortality among US veterans with a robust physiologic reserve undergoing open or endovascular abdominal aortic aneurysm repair.

Pre-Operative Moderate to Severe Chronic Kidney Disease is Associated with Worse Short-Term and Mid-Term Outcomes in Patients Undergoing Fenestrated-Branched Endovascular Aortic Repair

OBJECTIVE

To review experience of fenestrated-branched endovascular aortic repair (F-BEVAR) for pararenal/thoraco-abdominal aortic aneurysms (PRAA/TAAA) and to assess the association between pre-operative moderate to severe chronic kidney disease (CKD) and post-operative outcomes.

METHODS

All consecutive patients undergoing (elective and non-elective) F-BEVAR at a single centre (1 January 2011 - 1 July 2019) were identified. Renal function was calculated as the estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease formula. Accordingly, presence of moderate to severe CKD was defined as eGFR < 60 mL/min/1.73m².

RESULTS

Overall, 202 consecutive patients (mean age 72 ± 8 years; 25% women) underwent F-BEVAR for the treatment of PRAA/TAAA during the study period. Of these, 51 had a history of moderate to severe CKD (none on chronic haemodialysis). No statistically significant differences were found in demographics and major comorbidities between patients with or without a history of CKD. The overall peri-operative mortality rate was 2%, without statistically significant differences between study groups (p = .26). Patients with prior CKD had statistically significantly higher rates of acute kidney injury (AKI) (37% vs. 12%, p < .001). At three years, overall survival was statistically significantly lower in patients with history of CKD compared with those without pre-operative CKD (57% vs. 82%, p = .010). Similarly, freedom from renal function decline at three years was statistically significantly poorer in patients with prior history of CKD compared with those without pre-operative CKD (43% vs. 80%, p = .020). In a multivariable analysis CKD was independently associated with higher odds of peri-operative AKI (OR 2.8, 95% CI 1.9 - 5.8, p = .030), renal function decline (OR 4.9, 95% CI 1.7 - 9.2, p = .003), and all cause mortality (HR 3.2, 95% CI 1.2 - 8.6, p = .020).

CONCLUSION

Despite low peri-operative mortality rates that are comparable to patients with unimpaired renal function, occurrence of AKI was statistically significantly higher in subjects with pre-existing moderate to severe CKD. History of CKD was independently associated to renal function decline and poorer midterm survival.

Outcomes after endovascular reintervention for aortic interventions

OBJECTIVE

Endovascular reinterventions are often performed after previous open or endovascular aortic procedures. We used the GREAT (Global Registry for Endovascular Aortic Treatment) database to compare the outcomes between these groups. We also compared reintervention of any type with a group of patients who had undergone primary endovascular abdominal aortic aneurysm repair (EVAR).

METHODS

All patients enrolled in GREAT were grouped according to a previous EVAR or open abdominal aortic procedure (OAP). Univariate analysis was performed using the χ², Wilcoxon rank sum, and Fisher exact tests. Cox proportional analysis was used to test the predictors for all-cause and aorta-related mortality.

RESULTS

A total of 3974 subjects who had undergone EVAR with follow-up data available were included in the GREAT. Of the 3974 procedures, 196 (4.9%) were reinterventions (49 after OAP and 147 after previous EVAR). Reintervention after previous EVAR showed a trend toward a greater endoleak rate through 2 years (13.6% vs 4.1%; P = .07), although no difference was found in the occurrence of the intervention (12.2% vs 17.7%; P = .37). Reintervention after OAP resulted in higher all-cause mortality through 2 years of follow-up (32.7% vs 17.7%; P = .0.03). The predictors of mortality included prior OAP, renal insufficiency, and the use of cutdown for access. Compared with the patients who had undergone primary endovascular repair, patients in the reintervention cohort were older (75.3 years vs 73.3 years; P = .0005), had had only femoral artery access used (95.8% vs 90.3%; P < .0001), and were more likely to have undergone aortic branch vessel procedures (32.3% vs 13.3%; P < .0001). Both all-cause and aorta-related mortality through 2 years was higher in the reintervention group than in the primary EVAR group (21.4% vs 12.5% [P = .0003; and 4.6% vs 1% [P < .0001], respectively). On multivariate analysis, the predictors of aortic-related mortality included reintervention, renal insufficiency, chronic obstructive pulmonary disease, underweight body mass index, increasing aortic diameter, and the use of brachial artery or other arterial access sites.

CONCLUSIONS

Endovascular reintervention for aortic pathology was associated with higher mortality than was primary EVAR. Reinterventions after prior OAPs were associated with higher mortality than were prior EVARs.

Surgeon volume and established hospital perioperative mortality rate together predict for superior outcomes after open abdominal aortic aneurysm repair

BACKGROUND

In 2018, the Society for Vascular Surgery (SVS) published hospital volume guidelines for elective open abdominal aortic aneurysm (AAA) repair, recommending that elective open surgical repair of AAAs should be performed at centers with an annual volume of ≥10 open aortic operations of any type and a documented perioperative mortality of ≤5%. Recent work has suggested a yearly surgeon volume of at least seven open aortic cases for improved outcomes. The objective of the present study was to assess the importance of hospital volume and surgeon volume at these cut points for predicting 1-year mortality after open surgical repair of AAAs.

METHODS

We evaluated patients who had undergone elective open AAA repair using the New York Statewide Planning and Research Cooperative System database from 2003 to 2014. The effect of the SVS guidelines on postoperative mortality and complications was evaluated. Confounding between the hospital and surgeon volumes was identified using mixed effects multivariate Cox proportional hazards analysis. The effect of the interactions between hospital volume, established hospital perioperative survival, and surgeon volume on postoperative outcomes was also investigated.

RESULTS

The cohort consisted of 7594 elective open AAA repairs performed by 542 surgeons in 137 hospitals during the 12-year study period. Analysis of the 2018 guidelines using the Statewide Planning and Research Cooperative System database revealed 1-year and 30-day mortality rates of 9.2% (range, 8.3%-10.1%) and 3.5% (range, 2.9%-4.1%) for centers that were within the SVS guidelines and 13.6% (range, 12.5%-14.7%) and 6.9% (range, 6.1%-7.8%) for those that were outside the guidelines, respectively (P < .001 for both). Multivariate survival analysis revealed a hazard ratio for a surgeon volume of ≥7, hospital volume of ≥10, and hospital 3-year perioperative mortality of ≤5% of 0.80 (95% confidence interval [CI], 0.70-0.93; P = .003), 0.91 (95% CI, 0.77-1.08; P = .298), and 0.72 (95% CI, 0.62-0.82; P < .001), respectively. Additionally, procedures performed by surgeons with a yearly average volume of open aortic operations of at least seven and at hospitals with an established elective open AAA repair perioperative mortality rate of ≤5% showed improved 1-year (33.2% relative risk reduction; P < .001) and 30-day (P = .001) all-cause survival and improved postoperative complication rates.

CONCLUSIONS

These data have demonstrated that centers that meet the SVS AAA volume guidelines are associated with improved 1-year and 30-day all-cause survival. However, the results were confounded by surgeon volume. A surgeon open aortic volume of at least seven procedures and an established hospital perioperative mortality of ≤5% each independently predicted for 1-year survival after open AAA repair, with the hospital volume less important. These results indicate that surgeons with an annual volume of at least seven open aortic operations of any type should perform elective open AAA repair at centers with a documented perioperative mortality of ≤5%.

Nationwide Study of Ruptured Abdominal Aortic Aneurysms During Twenty Years (1994-2013)

OBJECTIVE

To analyze the epidemiology of ruptured abdominal aortic aneurysms (RAAA) in Sweden over 20 years, and assess the effect of endovascular repair (EVAR) on surgical treatment rate and outcome.

METHODS

All Swedish citizens >50 years with RAAA 1994 to 2013 were extracted from 3 national (Cause of Death, Patient, and Vascular Surgical) registries. Incidence, proportion repaired, surgical techniques, and 90-day mortality were assessed based on sex and age groups, with regression analysis.

RESULTS

18,726 individuals with RAAA were identified, 74.0% men. The incidence of RAAA decreased from 33.1/100,000: 1994 to 21.3/100,000: 2013 (relative change -35.6%, P < 0.001). The proportion of men with RAAA undergoing repair was 44.5%: 1994-1998, 49.7%: 2009-2013 (+11.7%, P < 0.001). In women, 22.3% were repaired in 1994-1998, versus 28.2%: 2009-2013 (+26.4%, P < 0.001). The proportion undergoing repair increased in octogenarians (men: +44.3%, P < 0.001; women +49.3%, P = 0.001). EVAR increased from 0% initially to 42.3% in men and 41.2% in women 2013. Overall, mortality rate among all individuals with RAAA decreased, men 75.8%: 1994-1998, 64.8%: 2009-2013 (-14.5%, P < 0.001); women 88.5%: 1994-1998, 82.2%: 2009-2013 (-7.1%, P < 0.001). Among those who underwent repair, mortality was 47.0% in men: 1994-1998, 31.8%: 2009-2013 (-32.3%, P < 0.001); women 51.8%: 1994-1998, 41.4%: 2009-2013 (-20.1%, P = 0.010).

CONCLUSION

RAAA mortality among men decreased, mainly attributed to falling incidence of RAAA. The mortality was further reduced by more patients being offered repair, increasingly often with EVAR, and improved survival after repair. Incidence of rupture remained unchanged among women, who had higher RAAA mortality. Focused efforts to reduce RAAA mortality among women are warranted.

Vitamin K2 Dependent Matrix Gla Protein Relating to Abdominal Aortic Aneurysm and Overall Mortality: A Combined Case Control and Cohort Study

OBJECTIVE

Inactivation of matrix Gla protein (MGP), using vitamin K antagonists or vitamin K deficiency results in increased vascular calcification, which has been associated with increased risk of symptomatic or ruptured abdominal aortic aneurysm (AAA). Insufficient activation of MGP leads to increased levels of undercarboxylated forms of MGP, measured as a dephosphorylated, undercarboxylated MGP (dp-ucMGP) in plasma. This study aimed to investigate whether the level of inactivated MGP influenced the risk of having an AAA, the risk of AAA progression, and overall mortality.

METHODS

This combined case control and cohort study was based on data from the randomised, clinically controlled Viborg Vascular (VIVA) screening trial. Cases (n = 487) with an AAA and controls (n = 189) with neither peripheral artery disease nor AAA, had their plasma quantified for dp-ucMGP. Plasma levels were compared with the presence of an AAA, AAA growth rate, need for repair, and overall mortality. dp-ucMGP was divided into tertiles in regression analyses.

RESULTS

The plasma levels of dp-ucMGP were higher for AAA cases compared with controls (median of 517 pmol/L vs. 495 pmol/L, p = .036). Adjusted analyses regarding dp-ucMGP being predictive of AAA, AAA growth rate, and need for repair all failed to show correlation. Overall mortality for AAA cases exhibited a significant association for the third tertile of dp-ucMGP with a hazard ratio of 2.55 (95% CI 1.29 - 5.05) compared with the first tertile. Overall mortality for controls was not correlated with dp-ucMGP plasma levels.

CONCLUSION

dp-ucMGP did not correlate with the risk of having an AAA, AAA growth rate, or risk of surgery. For people with an AAA, dp-ucMGP was correlated with an increased mortality risk for the highest tertile of dp-ucMGP. This could suggest a role for prophylactic measures with vitamin K2 supplements to people at risk of AAA.

Prehabilitation exercise therapy before elective abdominal aortic aneurysm repair

BACKGROUND

An abdominal aortic aneurysm (AAA) is an abnormal dilation in the diameter of the abdominal aorta of 50% or more of the normal diameter or greater than 3 cm in total. The risk of rupture increases with the diameter of the aneurysm, particularly above a diameter of approximately 5.5 cm. Perioperative and postoperative morbidity is common following elective repair in people with AAA. Prehabilitation or preoperative exercise is the process of enhancing an individual's functional capacity before surgery to improve postoperative outcomes. Studies have evaluated exercise interventions for people waiting for AAA repair, but the results of these studies are conflicting.

OBJECTIVES

To assess the effects of exercise programmes on perioperative and postoperative morbidity and mortality associated with elective abdominal aortic aneurysm repair.

SEARCH METHODS

We searched the Cochrane Vascular Specialised register, Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Physiotherapy Evidence Database (PEDro) databases, and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 6 July 2020. We also examined the included study reports' bibliographies to identify other relevant articles.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) examining exercise interventions compared with usual care (no exercise; participants maintained normal physical activity) for people waiting for AAA repair.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, assessed the included studies, extracted data and resolved disagreements by discussion. We assessed the methodological quality of studies using the Cochrane risk of bias tool and collected results related to the outcomes of interest: post-AAA repair mortality; perioperative and postoperative complications; length of intensive care unit (ICU) stay; length of hospital stay; number of days on a ventilator; change in aneurysm size pre- and post-exercise; and quality of life. We used GRADE to evaluate certainty of the evidence. For dichotomous outcomes, we calculated the risk ratio (RR) with the corresponding 95% confidence interval (CI).

MAIN RESULTS

This review identified four RCTs with a total of 232 participants with clinically diagnosed AAA deemed suitable for elective intervention, comparing prehabilitation exercise therapy with usual care (no exercise). The prehabilitation exercise therapy was supervised and hospital-based in three of the four included trials, and in the remaining trial the first session was supervised in hospital, but subsequent sessions were completed unsupervised in the participants' homes. The dose and schedule of the prehabilitation exercise therapy varied across the trials with three to six sessions per week and a duration of one hour per session for a period of one to six weeks. The types of exercise therapy included circuit training, moderate-intensity continuous exercise and high-intensity interval training. All trials were at a high risk of bias. The certainty of the evidence for each of our outcomes was low to very low. We downgraded the certainty of the evidence because of risk of bias and imprecision (small sample sizes). Overall, we are uncertain whether prehabilitation exercise compared to usual care (no exercise) reduces the occurrence of 30-day (or longer if reported) mortality post-AAA repair (RR 1.33, 95% CI 0.31 to 5.77; 3 trials, 192 participants; very low-certainty evidence). Compared to usual care (no exercise), prehabilitation exercise may decrease the occurrence of cardiac complications (RR 0.36, 95% CI 0.14 to 0.92; 1 trial, 124 participants; low-certainty evidence) and the occurrence of renal complications (RR 0.31, 95% CI 0.11 to 0.88; 1 trial, 124 participants; low-certainty evidence). We are uncertain whether prehabilitation exercise, compared to usual care (no exercise), decreases the occurrence of pulmonary complications (RR 0.49, 95% 0.26 to 0.92; 2 trials, 144 participants; very low-certainty evidence), decreases the need for re-intervention (RR 1.29, 95% 0.33 to 4.96; 2 trials, 144 participants; very low-certainty evidence) or decreases postoperative bleeding (RR 0.57, 95% CI 0.18 to 1.80; 1 trial, 124 participants; very low-certainty evidence). There was little or no difference between the exercise and usual care (no exercise) groups in length of ICU stay, length of hospital stay and quality of life. None of the studies reported data for the number of days on a ventilator and change in aneurysm size pre- and post-exercise outcomes.

AUTHORS' CONCLUSIONS

Due to very low-certainty evidence, we are uncertain whether prehabilitation exercise therapy reduces 30-day mortality, pulmonary complications, need for re-intervention or postoperative bleeding. Prehabilitation exercise therapy might slightly reduce cardiac and renal complications compared with usual care (no exercise). More RCTs of high methodological quality, with large sample sizes and long-term follow-up, are needed. Important questions should include the type and cost-effectiveness of exercise programmes, the minimum number of sessions and programme duration needed to effect clinically important benefits, and which groups of participants and types of repair benefit most.

Early and mid-term outcomes following open surgical conversion after failed endovascular aneurysm repair from the "Italian North-easT RegIstry of surgical Conversion AfTer Evar" (INTRICATE)

OBJECTIVE

To report the early and mid-term outcomes following open surgical conversion (OSC) after failed endovascular aortic repair (EVAR) using data from a multicentric registry.

METHODS

A retrospective study was carried out on consecutive patients undergoing OSC after failed EVAR at eight tertiary vascular units from the same geographic area in the North-East of Italy, from April 2005 to November 2019. Study endpoints included early and follow-up outcomes.

RESULTS

144 consecutive patients were included in the study. Endoleaks were the most common indication for OSC (50.7%), with endograft infection (24.6%) and occlusion (21.9%) being the second most prevalent causes. The overall rate of 30-day all-cause mortality was 13.9% (n=20); 32 patients (22.2%) experienced at least one major complication. Mean length of stay (LoS) was 13 ± 12.7 days. On multivariate logistic regression, age (OR 1.09, 95% CI 1.01-1-19, p= .02), renal clamping time (OR 1.07, 95% CI 1.02-1.13, p= .01), and suprarenal/celiac clamping (OR 6.66, 95% CI 1.81-27.1, p= .005) were identified as independent predictors of peri-operative major complications. Age was the only factor associated with peri-operative mortality at 30 days. Renal clamping time > 25 minutes had sensitivity of 65% and specificity of 70% in predicting the occurring of major adverse events (AUC 0.72; 95% CI 0.61-0.82). At 5 years, estimated survival was significantly lower for patients treated due to aortic rupture/dissection (28%, 95% CI 13-61), compared to patients in whom the indication for treatment was endoleak (54%, 95% CI 40-73), infection (53%, 95% CI 30-94), or thrombosis (82%, 95% CI 62-100; p= .0019). 5-year survival rates were significantly lower in patients who received emergent treatment (28%, 95% CI 14-55) as compared with those who were treated in urgent (67%, 95% CI 48-93) or elective setting (57%, 95% CI 43-76; p= .00026). Subjects who received suprarenal/celiac (54%, 95% CI 36-82) or suprarenal (46%, 95% CI 34-62) aortic cross-clamping had lower survival rates at 5 years than those whose aortic-cross clamp site was infrarenal (76%, 95% CI 59-97; p= .041). Using multivariate Cox Proportional Hazard, older age and emergency setting were independently associate with higher risk for overall 5 years mortality.

CONCLUSIONS

OSC after failed EVAR was associated with relatively high rates of early morbidity and mortality, particularly for emergency setting surgery. Endoleaks with secondary sac expansion were the main indication for OSC and suprarenal aortic cross-clamping was frequently required. Endograft infection and emergent treatment remained associated with poorer short-term and long-term survival.

Preoperative Leukocytosis Among Female Patients Predicts Poor Postoperative Outcomes Following EVAR For Intact Infrarenal AAA

OBJECTIVES

Elevated white blood count (WBC) can be predictive of adverse outcomes following vascular interventions, but the association has not established using multi-institutional data. We evaluated the predictive value of preoperative WBC after endovascular abdominal aortic aneurysm repair (EVAR) for non-ruptured abdominal aortic aneurysms (AAA) in a nationally representative surgical database.

METHODS

Patients with non-ruptured AAA undergoing EVAR were identified in the vascular-targeted National Surgical Quality Improvement Program (NSQIP) database. Baseline characteristics were compared between patients with WBC < 10 K/μL and WBC ≥ 10 K/μL. Multivariable logistic regression analyses were performed to assess the odds of outcomes. The primary outcome was 30-day mortality. Multiple secondary outcomes including length of stay (LOS) > 1 week, 30-day readmission, lower extremity (LE) ischemia, ischemic colitis, myocardial infarction (MI) and others were assessed based on WBC and patient sex.

RESULTS

A total of 10955 patients were included with a mean WBC 7.7 ± 2.7 K/μL. Patients with WBC ≥ 10 K/μL were younger (71.8 ± 9.5 years versus 74.1 ± 8.7 years; P < .001) and were more likely to be diabetic, on steroids, smokers, functionally dependent and presenting emergently (all P ≤ .009). Aneurysm diameter was larger in WBC ≥ 10 K/μL patients (5.9 ± 1.5 cm versus 5.7 ± 1.5 cm; P < .001). Patients with WBC ≥ 10 K/μL had more mortality (2.4% vs 1.3%), LOS > 1 week (13.5% versus 6.7%), 30-day readmissions (9.8% versus 7.3%), LE ischemia (2.3% vs 1.4%), ischemic colitis (1.2% vs 0.5%), and MI (2.0% vs 1.1% ) (all P ≤ .008). Female patients with WBC ≥ 10 K/μL, compared to male patients with WBC ≥ 10 K/μL had more adverse events including mortality, LOS > 1 week, 30-day readmission, LE ischemia (all P ≤ .025). With each incremental increase in WBC by 1K/μL, the adjusted odds ratio of adverse outcomes for all patient was higher (mortality: 1.05 [95% CI, 1.00-1.10], readmission: 1.03 [95% CI, 1.00-1.06], LOS > 1 week: 1.08 [95% CI, 1.05-1.10] and ischemic colitis: 1.11 [95% CI, 1.05-1.16]; all P < .05). The effect was more pronounced in female patients and statistically significant.

CONCLUSIONS

WBC is a predictor of adverse outcomes in patients undergoing EVAR for non-ruptured AAA. After adjusting for associated risk factors, the effect of increasing WBC was more prominent for female patients. Preoperative WBC should be used as a prognostic factor to predict adverse outcomes among EVAR patients.

Modelling the impact of changes to abdominal aortic aneurysm screening and treatment services in England during the COVID-19 pandemic

Background

The National Health Service (NHS) abdominal aortic aneurysm (AAA) screening programme (NAAASP) in England screens 65-year-old men. The programme monitors those with an aneurysm, and early intervention for large aneurysms reduces ruptures and AAA-related mortality. AAA screening services have been disrupted following COVID-19 but it is not known how this may impact AAA-related mortality, or where efforts should be focussed as services resume.

Methods

We repurposed a previously validated discrete event simulation model to investigate the impact of COVID-19-related service disruption on key outcomes. This model was used to explore the impact of delayed invitation and reduced attendance in men invited to screening. Additionally, we investigated the impact of temporarily suspending scans, increasing the threshold for elective surgery to 7cm and increasing drop-out in the AAA cohort under surveillance, using data from NAAASP to inform the population.

Findings

Delaying invitation to primary screening up to two years had little impact on key outcomes whereas a 10% reduction in attendance could lead to a 2% lifetime increase in AAA-related deaths. In surveillance patients, a 1-year suspension of surveillance or increase in the elective threshold resulted in a 0.4% increase in excess AAA-related deaths (8% in those 5–5.4cm at the start). Longer suspensions or a doubling of drop-out from surveillance would have a pronounced impact on outcomes.

Interpretation

Efforts should be directed towards encouraging men to attend AAA screening service appointments post-COVID-19. Those with AAAs on surveillance should be prioritised as the screening programme resumes, as changes to these services beyond one year are likely to have a larger impact on surgical burden and AAA-related mortality.

The Association of Spondylitis and Aortic Aneurysm Disease

OBJECTIVES

The aim of this study is to assess any relation between spondylitis and aortic aneurysmal disease by reviewing the current literature.

METHODS

A systematic search was undertaken using MEDLINE, EMBASE and CENTRAL databases till May 2019, for articles reporting on patients suffering from spondylitis and aortic aneurysm.

RESULTS

The most involved aortic segment was infrarenal aorta (56.9%). The lumbar vertebrae were more frequently affected (79.7%). Commonest symptoms were back pain (79.1%), fever (33.7%) and lower limb pain (29.1%). 55.8% of cases were diagnosed using computed tomography. The pathology was attributed to infectious causes in 25.1% of cases. 53.4% of patients were treated only for the aneurysm, 27.9% for both pathologies, while two patients solely for the vertebral disease. Endovascular aneurysm repair was chosen in 12.8% of cases. The 30-day mortality was 8.1% (7/86); mostly from vascular complications.

CONCLUSIONS

A synchronous spondylitis and aortic aneurysm may share common etiopathology, when an infectious or inflammatory cause is presented. The lumbar vertebrae are more frequently affected. Low quality data do not allow safe conclusion to suggest the best treatment option.

Differences in Comorbidities Between Women and Men Treated with Elective Repair for Abdominal Aortic Aneurysms: A Systematic Review and Meta-Analysis

OBJECTIVES

Elective abdominal aortic aneurysm (AAA) repair is performed to prevent rupture. For reasons as yet unknown, the 30-day mortality risk after elective AAA repair is higher in women than in men. We hypothesised that this higher risk might be related to differences in comorbidity.

METHODS

Systematic review (PROSPERO CRD42019133314) according to PRISMA guidelines. A search in the EMBASE/MEDLINE/CENTRAL databases identified 1870 studies that included patients who underwent elective AAA repair (final search February 17^th, 2021). Ultimately, 28 studies were included and all reported comorbidities were categorised into 17 comorbidity groups. Additionally, 15 groups of clearly defined comorbidities were used for sensitivity analysis. For both groups, meta-analyses of each comorbidity were performed to estimate the difference in pooled prevalence between women and men with a random effects model.

RESULTS

When analysing data of all reported comorbidities (17 groups), smoking [risk difference (RD) 11%, 95% confidence interval (CI) 4-18], diabetes (RD 3%, 95% CI 2-4), ischaemic heart disease (RD 12%, 95% CI 8-16), arrhythmia (RD 3%, 95% CI 0.4-5), liver disease (RD 0.1%, 95% CI 0.01-0.2), and cancer (RD 3%, 95% CI 2-4)) were less prevalent in women, whereas, hypertension (RD 4%, 95% CI 3-6) and pulmonary disease (RD 4%, 95% CI 3-5) were more prevalent in women. At the time of surgery women were significantly older than men (74.9 years versus 72.4; mean difference 2.4 years (95% CI 2.1-2.7)). In the sensitivity analysis of 15 comorbidity groups, the same comorbidities remained significantly different between women and men, except smoking and arrhythmia. Women had a higher mortality risk than men (RD 1%, 95% CI 1-2).

CONCLUSIONS

Although women undergoing elective AAA repair have fewer baseline comorbidities than men, their 30-day mortality risk is higher. In-depth studies on the cause of death in women after elective AAA repair are needed to explain this discrepancy in mortality.

Nationwide study of surgery for primary infected abdominal aortic and common iliac artery aneurysms

BACKGROUND

Primary infected aneurysms of the abdominal aorta and iliac arteries are potentially life-threatening. However, because of the rarity of the disease, its pathogenesis and optimal treatment strategy remain poorly defined.

METHODS

A nationwide retrospective cohort study investigated patients who underwent surgical treatment for a primary infected abdominal aortic and/or common iliac artery (CIA) aneurysm between 2011 and 2017 using a Japanese clinical registry. The study evaluated the relationships between preoperative factors and postoperative outcomes including 90-day and 3-year mortality, and persistent or recurrent aneurysm-related infection. Propensity score matching was used to compare survival between patients who underwent in situ prosthetic grafting and those who had endovascular aneurysm repair (EVAR).

RESULTS

Some 862 patients were included in the analysis. Preceding infection was identified in 30.2 per cent of the patients. The median duration of postoperative follow-up was 639 days. Cumulative overall survival rates at 30 days, 90 days, 1 year, 3 years and 5 years were 94.0, 89.7, 82.6, 74.9 and 68.5 per cent respectively. Age, preoperative shock and hypoalbuminaemia were independently associated with short-term and late mortality. Compared with open repair, EVAR was more closely associated with persistent or recurrent aneurysm-related infection (odds ratio 2.76, 95 per cent c.i. 1.67 to 4.58; P < 0.001). Propensity score-matched analyses demonstrated no significant differences between EVAR and in situ graft replacement in terms of 3-year all-cause and aorta-related mortality rates (P = 0.093 and P =0.472 respectively).

CONCLUSION

In patients undergoing surgical intervention for primary infected abdominal aortic and CIA aneursyms, postoperative survival rates were encouraging. Eradication of infection following EVAR appeared less likely than with open repair, but survival rates were similar in matched patients between EVAR and in situ graft replacement.

A Review of UK-based National and International Scientific Meeting Published Abstracts in Response to the Draft NICE Aortic Aneurysm Guidelines

BACKGROUND

UK National Institute for Health and Care Excellence (NICE) draft clinical guidelines (CG) (2018) regarding aortic aneurysm repair were disputed internationally. We aim to appraise the academic response to the draft CG in terms of quantity and scientific quality by reviewing published conference abstracts from three major national and international, UK meetings.

METHODS

Abstracts related to aortic practice from The Vascular Societies Annual Scientific Meeting, British Society for Endovascular Therapy (BSET) & Charing Cross (CX) meetings from 2019 were reviewed for methodology, sample size, data collection period, scientific quality and conclusions that supported or conflicted the draft guideline.

RESULTS

A total of 549 abstracts were identified from VSGBI, BSET and CX abstract books of which, 226 (41.2%) were related to aortic practices. Of these, 115 (50.9%) were related to EVAR. Twenty-two of these abstracts (19.1%) were identified as having findings relevant to the draft guidelines. Eighteen (15.7%) were identified as findings that potentially conflict the draft CG and 4 (3.5%) that could support the initial recommendations. Six abstracts (5.2%) made direct reference to or challenged the draft CG. The median data collection period was 4 years. The median sample size was 102 patients. In general, scientific quality was poor, with 82% of selected abstracts were graded at level 2b.

CONCLUSION

We have demonstrated a concerted response to the draft NICE clinical guidelines relating to the treatment of abdominal aortic aneurysms at three large scientific meetings. As a result of which and other factors, significant changes were made to the finalized NG156. There is still paucity in evidence regarding the long-term safety and cost-effectiveness of EVAR.

Association of Metformin and Abdominal Aortic Aneurysm Repair Outcomes

BACKGROUND

Metformin is a commonly used drug in diabetes mellitus treatment. Recently it has been suggested that the use of metformin on diabetes mellitus patients may lower the prevalence and slow the progression of AAA (abdominal aortic aneurysm) as well as the risk of rupture related mortality. The aim of this studywas to investigate the impact of metformin treatment on the risk of AAA repair related mortality and surgical complications.

METHODS

In this retrospective study, the clinical data of 306 patients, including 77 patients with diabetes mellitus, who underwent abdominal aortic aneurysm repair has been analyzed. Treatment outcomes have been investigated. The diabetes and metformin prescription status has been obtained from the medical history. Patients were divided into three groups: diabetes-free individuals, diabetics treated with metformin and diabetics treated with other glucose lowering drugs. The association between metformin treatment and AAA diameter, surgical complications and mortality were assessed using chi-square independence test and odds ratio analysis. In order to assess which factors are influencing AAA repair related complications and mortality a multi-variables analysis has been performed.

RESULTS

A significant protective effect of metformin treatment towards AAA repair related mortality (P = 0.019) and complications (P = 0.032) among patients suffering from diabetes mellitus was revealed. These findings were statistically insignificant when considering all groups of patients (diabetes-free individuals, diabetics treated with metformin and diabetics treated with other glucose lowering drugs).

CONCLUSION

Metformin may lower the risk of AAA repair related mortality and surgical complications among patients with diabetes.

Towards a Core Outcome Set for Abdominal Aortic Aneurysm: Systematic Review of Outcomes Reported Following Intact and Ruptured Abdominal Aortic Aneurysm Repair

OBJECTIVE

To encompass the needs of all stakeholders and allow effective data synthesis from trials, registries, and other studies; a core outcome set for infrarenal abdominal aortic aneurysm (AAA) repair is needed. In this first stage, the aim was to report the range, frequency, and time of pre-specified outcomes reported following AAA repair.

DATA SOURCES

Medline, Embase, and CENTRAL databases 2010 - 2019 were searched using ProQuest Dialog™.

REVIEW METHODS

The systematic review was reported to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines (PRISMA), PROSPERO registration CRD42019130119. Outcomes were coded using Core Outcome Measures in Effectiveness Trials (COMET) taxonomy and presented separately for intact and rupture repairs, endovascular aneurysm repair (EVAR) and open repair, and time from repair (acute < 90 days vs. ≥ 1 year) (COMET Initiative 1582).

RESULTS

For intact AAA and rupture repair, a total of 231 and 70 reports with 589 255 and 177 465 patients respectively were included: only 98 and 19 respectively provided ≥ 1 year outcomes. Most studies were retrospective, with 13 randomised trials of intact AAA repair and five randomised trials of ruptured AAA repair. For intact AAA, the most common pre-specified COMET taxonomy outcomes were mortality (181), vascular complications (137), and re-intervention (52). EVAR studies dominated the vascular outcomes in acute and later time periods: excluding 47 reports from device registries, reduced vascular outcomes to 83. For ruptured AAA, the three most common outcomes were mortality (64), vascular (11), and hospital stay (10). The range of outcomes reported was wide with functioning outcomes reported from most randomised trials but few retrospective studies.

CONCLUSION

This review identifies the paucity of long term data and the disproportionate attention paid to vascular complications vs. patient functioning outcomes, this skew being accentuated by reporting from EVAR device registries. These data will inform focus groups, prior to a pan-European Delphi consensus, involving clinicians, patients, carers and providers, for developing core outcomes for repair of intact and ruptured AAA.

The Content of Pre-habilitative Interventions for Patients Undergoing Repair of Abdominal Aortic Aneurysms and Their Effect on Post-Operative Outcomes: A Systematic Review

OBJECTIVE

Patients requiring abdominal aortic aneurysm (AAA) repair are at risk of post-operative complications due to poor pre-operative state. Pre-habilitation describes the enhancement of functional capacity and tolerance to an upcoming physiological stressor, intended to reduce those complications. The ability to provide such an intervention (physical, pharmacological, nutritional, or psychosocial) between diagnosis and surgery is a growing interest, but its role in AAA repair is unclear. This paper aimed to systematically review existing literature to better describe the effect of pre-habilitative interventions on post-operative outcomes of patients undergoing AAA repair.

DATA SOURCES

EMBASE and Medline were searched from inception to October 2020. Retrieved papers, systematic reviews, and trial registries were citation tracked.

REVIEW METHODS

Randomised controlled trials (RCTs) comparing post-operative outcomes for adult patients undergoing a period of pre-habilitation prior to AAA repair (open or endovascular) were eligible for inclusion. Two authors screened titles for inclusion, assessed risk of bias, and extracted data. Primary outcomes were post-operative 30 day mortality, composite endpoint of 30 day post-operative complications, hospital length of stay (LOS), and health related quality of life (HRQL) outcomes. The content of interventions was extracted and a narrative analysis of results undertaken.

RESULTS

Seven RCTs with 901 patients were included (three exercise based, two pharmacological based, and two nutritional based). Risk of bias was mostly unclear or high and the clinical heterogeneity between the trials precluded data pooling for meta-analyses. The quality of intervention descriptions was highly variable. One exercise based RCT reported significantly reduced hospital LOS and another improved HRQL outcomes. Neither pharmacological nor nutritional based RCTs reported significant differences in primary outcomes.

CONCLUSION

There is limited evidence to draw clinically robust conclusions about the effect of pre-habilitation on post-operative outcomes following AAA repair. Well designed RCTs, adhering to reporting standards for intervention content and trial methods, are urgently needed to establish the clinical and cost effectiveness of pre-habilitation interventions.

Characteristics and outcomes of small abdominal aortic aneurysm rupture in the American College of Surgeons National Surgical Quality Improvement Program database

OBJECTIVE

The current guidelines recommend elective abdominal aortic aneurysm (AAA) repair at 5.5 cm for men and 5.0 cm for women. However, rupture can occur in patients with an aneurysm smaller than these size thresholds. In the present study, we investigated the proportion of AAAs that rupture at sizes less than elective operative thresholds and compared the outcomes of repair with those of aneurysms that had ruptured at a larger size. Our hypothesis was that the rupture of small AAAs carries mortality similar to that of rupture at larger sizes.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program targeted vascular files for open AAA repair and endovascular aneurysm repair (EVAR) were reviewed for all cases of ruptured AAAs (rAAAs) from 2011 to 2018. The patients were divided into two groups: those with small AAAs that had ruptured at a size less than the current size guidelines for elective repair and those with large AAAs that had ruptured at a size that had met the criteria for elective repair. Univariate analyses were conducted to compare the comorbidities and perioperative outcomes of infrarenal rAAA repair between the groups. Multivariable logistic regression was performed to examine the differences in mortality between small and large rAAAs after controlling for confounding variables.

RESULTS

Of the 1612 rAAA repairs, 167 (10.4%) were small rAAAs. The proportion of small rAAAs did not significantly change during the study period (P = .15). The large rAAA group was more likely to have juxtarenal or suprarenal aneurysms compared with the small rAAA group (27% vs 16%; P = .001). A comparison of infrarenal rAAAs only demonstrated that the mean small rAAA (n = 141) diameter was 4.1 cm in the women and 4.5 cm in the men compared with the large rAAAs (n = 1051), with a mean diameter of 7.1 cm in women and 8.3 cm in men (P < .01 for the women; P < .01 for the men). The patients in the small rAAA group had had a significantly lower body mass index but were more likely to be African American and to have hypertension. The small rAAA group was more likely to present without hypotension and to have undergone EVAR. The repair of small rAAAs was associated with lower bleeding and mortality and a shorter mean operative time but with more readmissions. Multivariable regression analysis demonstrated that size was not associated with outcome after adjusting for other variables.

CONCLUSIONS

Of all AAA repairs classified as treating rupture, 10% were for patients with small AAAs. Patients with small rAAA were less likely to present with hypotension and were more likely to have undergone EVAR. Further research into sac morphology and more sensitive imaging modalities might help identify small rAAAs at high risk of rupture that would benefit from elective repair.

Initial experience with the Terumo aortic Treo device for fenestrated endovascular aneurysm repair

OBJECTIVE

The Terumo aortic (TA) Treo device (Terumo, Somerset, NJ) is an endograft with unique features that lends itself to fenestrated endovascular aneurysm repair (FEVAR), including a low device profile, a wide amplitude stent design, and an increased interstent distance. We have described our initial experience with the Treo device for FEVAR to treat short neck and juxtarenal abdominal aortic aneurysms.

METHODS

As part of an ongoing physician-sponsored investigational device exemption clinical trial (ClinicalTrials.gov identifier, NCT01538056), subjects were prospectively enrolled and underwent elective FEVAR using a variety of devices. Demographic and procedural details were collected. The data from subjects treated specifically with the Treo device from November 3, 2016 to May 2, 2019 were collected and analyzed.

RESULTS

Of a cohort of 161 patients who had undergone elective FEVAR, 46 had been treated with the TA Treo device. Most patients were men (70%), with a mean age of 75 years and high rates of hypertension (74%), hyperlipidemia (83%), coronary artery disease (33%), and chronic obstructive pulmonary disease (33%). The mean aneurysm size was 66 mm, the mean preoperative infrarenal neck length was 5 mm, and the mean final seal zone length was 45 mm. The average hospital and intensive care unit lengths of stay were 2.4 and 1.5 days, respectively. A total of 129 fenestrations were created for 44 superior mesenteric and 85 renal arteries (2.8 fenestrations per patient). Technical success, defined as successful implantation of the device with all target vessels preserved, was 98% (45 of 46), with only one renal artery not successfully preserved. The mean follow-up period was 598 days. During the study period, 18 endoleaks were detected (17 type II and 1 type III), with one patient with a type III endoleak requiring reintervention. Three subjects had died within 30 days, one of intracranial hemorrhage, one of respiratory failure, and one of ischemic colitis. The graft modification times for the TA Treo were significantly shorter (43 minutes) than those for other commercially available devices (Cook Zenith, 55 minutes; Medtronic Endurant, 54 minutes; P < .0001).

CONCLUSIONS

Our institution has reported exclusive worldwide experience using the TA Treo device for FEVAR. This device provides for a highly efficient and technically successful procedure for most patients. The procedural and fluoroscopy times were low even in the setting of high complexity. The technical success rates and simplification of the FEVAR procedure have made this approach a preferred technique for most patients at our institution.

A systematic review of the effect of surgeon and hospital volume on survival in aortic, thoracic and fenestrated endovascular aneurysm repair

BACKGROUND

Endovascular aneurysm repair (EVAR) is becoming a mainstay in vascular surgery, both in metropolitan and regional hospitals. This review aims to assess the impact of hospital and surgeon volume on perioperative mortality specific to this surgery type to support the use of this treatment modality extensively.

METHODS

A literature search was performed on multiple dedicated medical databases using a detailed search strategy with terms focusing on hospital volume and EVARs. Inclusion and exclusion criteria were used to screen and evaluate suitable sources, focusing on operators and hospitals performing EVARs and the morbidity/mortality as outcomes. The results were then appraised using a PRISMA framework.

RESULTS

We reviewed 45 articles. Twelve articles met inclusion criteria for complete review. There was no level 1 evidence, and only a single systematic review and meta-analysis. EVAR and thoracic EVAR perioperative mortality had no correlation with hospital volume. Limited evidence was presented for fenestrated EVAR, where a mortality risk based on hospital volume remains unanswered. Open procedures for aneurysm repair had perioperative mortality outcomes that grossly correlated with hospital volume, supporting their use in high-volume centers.

CONCLUSIONS

With open aneurysm repairs having an increased mortality risk in low-volume centers, and endovascular treatment options gaining momentum, there is considerable support for the use of EVAR and thoracic EVAR in smaller regional centers safely and effectively. There is very limited evidence in the use of fenestrated EVAR, which remains unanswered, but presents a significant opportunity for research.

Survival and Living Situation After Ruptured Abdominal Aneurysm Repair in Octogenarians

OBJECTIVE

To determine the 30 day and one year mortality and post-operative living situation in octogenarians treated for ruptured abdominal aortic aneurysm (rAAA).

METHODS

A retrospective study was performed at four centres in the Netherlands. All consecutive patients aged ≥80 years, presenting with a rAAA between January 2013 and October 2018, were included. The primary outcomes were post-operative living situation and one year mortality.

RESULTS

In total, 157 patients were included. Forty-seven received palliative care and 110 patients had surgery. After endovascular or open repair, the one year mortality rate was 50.0%. The 30 day mortality rate was 40.8% (95% confidence interval [CI] 27-55) and 31.7% (95% CI 20-44), for endovascular and open repair, respectively (p = .32). Sixty-five per cent of survivors were discharged home, while 34.8% went to a nursing home for rehabilitation. Of the surviving patients, 82.6% went back to living in their pre-rupture home situation. Of the investigated variables, only a high body mass index proved a significant predictor of death at 30 days and one year. Compared with operated patients, patients turned down for surgery were older (mean age 87.5 ± 3.8 vs. 84.0 ± 3.5; p < .001), lived significantly more often in a nursing home (odds ratio 1.02, 95% CI 1.00-1.03; p < .001), were more often dependent (odds ratio 3.69, 95% CI 2.31-5.88; p < .001) and had a lower Glasgow Coma Scale score on arrival (odds ratio 0.42, 95% CI 0.25-0.69; p = .002). All palliative patients died within three days.

CONCLUSION

Overall treatment outcomes showed that octogenarians should not be denied surgery based on age alone, as half of the octogenarians that undergo surgical treatment are still alive one year after rAAA repair. In addition, > 80% returned to their own home after rehabilitation.

Reasons for and Outcomes of Open Abdominal Aortic Repair in the Endovascular Era

BACKGROUND

Endovascular aortic aneurysm repair (EVAR) has become the treatment of choice for most patients with abdominal aortic aneurysm (AAA). Open aneurysm repair (OAR) is still being used in a number of patients for specific reasons. The aim of the present study was to investigate the reasons and perioperative outcomes of OAR in a high-volume endovascular center.

METHODS

All patients who underwent OAR in a single center institution during the period April 2010 to July 2019 were retrospectively analyzed.

RESULTS

During the study period, 222 patients underwent OAR. One hundred and forty-one (63.5%) patients underwent elective surgery, and eighty-one (36.5%) patients were treated acutely. The reasons for the decision to perform OAR instead of EVAR were as follows: anatomical in 89 (40.1%) cases, rupture in unstable patient in 57 (25.7%) cases, AAA with concomitant iliac arterial occlusive disease in 44 (19.8%) cases, previous EVAR with complications in 14 (6.3%) cases, large pararenal aneurysm considered risky to wait for a customized fenestrated stent graft in 7 (3.2%) cases, young patient age in 4 (1.8%) cases, the patient's preference in 3 (1.4%) cases, infected/mycotic AAA in 2 (0.9%) cases, and simultaneous OAR with colon cancer resection (n = 1, 0.5%) and renal transplantation (n = 1, n = 0.5). Thirty-day mortality in elective cases was 5% (7/141) and in acute cases 34.6% (28/81).

CONCLUSIONS

This study shows that OAR is still used for selected patients despite improvements in EVAR technology. The most common reason for OAR was an unsuitable anatomy for EVAR. Perioperative mortality of OAR both for acute and elective cases as observed in this study is in line with published outcomes of other centers.

Five Year Patient Outcomes of Endovascular Abdominal Aortic Aneurysm Repair in the ENDURANT France Registry

OBJECTIVE

Endovascular repair is the preferred method of treatment for infrarenal abdominal aortic aneurysms with numerous publications from multiple geographic regions showing excellent patient outcomes. Since the original ACE (Anevrysme de l'aorte abdominale: Chirurgie versus Endoprothese) randomised control trial, studies of French specific population have also contributed significantly to the body of evidence in support of endovascular abdominal aortic repair.

METHODS

In the ENDURANT France registry, 180 patients were consecutively enrolled from 20 French centres starting in 2012. Investigational sites included public and private practice and differing centre volumes to be as representative of real world French experience as possible. The aim of this study was to present the five year outcomes from this registry.

RESULTS

Instructions for use (IFU) were respected in 97.8% (176/180) of patients. At five years, the Kaplan-Meier overall survival was 69.9% ± 3.5% and the freedom from aneurysm related death was 97.6% ± 1.2%. The freedom from Type IA endoleaks was 94.5% ± 1.7%, freedom from endoleaks of any type was 70.1 ± 3.4%, and freedom from secondary endovascular procedure 90.4% ± 2.6%. In addition, 61.6% (45/73) of patients exhibited sac shrinkage at five years.

CONCLUSION

In this five year report of the Endurant France registry, survival, re-intervention, and freedom from endoleak rates were comparable to recent EVAR registries and there was a high sac shrinkage rate. Secondary procedure and aneurysm rupture were lower than those of ACE, the French RCT which included older generation devices. This prospective registry demonstrates favourable five year outcomes of the Endurant stent graft used within IFU.

Psoas muscle area and attenuation are highly predictive of complications and mortality after complex endovascular aortic repair

OBJECTIVE

The present study evaluated the psoas muscle area and attenuation (radiodensity), quantified by computed tomography, together with clinical risk assessment, as predictors of outcomes after fenestrated and branched endovascular aortic repair (FBEVAR).

METHODS

The present single-center study included 504 patients who had undergone elective FBEVAR for pararenal or thoracoabdominal aortic aneurysms. The clinical risk assessment included age, sex, comorbidities, body mass index, glomerular filtration rate, aneurysm size and extent, cardiac stress test results, ejection fraction, and American Society of Anesthesiologists (ASA) score. Preoperative computed tomography was used to measure the psoas muscle area and attenuation at the L3 level. The lean psoas muscle area (LPMA; area in cm² multiplied by attenuation in Hounsfield units [HU]) was calculated by multiplying the area by the attenuation. The risk factors for 90-day mortality, major adverse events (MAEs), and long-term mortality were determined using multivariable analysis. MAEs included 30-day or in-hospital death, acute kidney injury, myocardial infarction, respiratory failure, paraplegia, stroke, and bowel ischemia. A novel risk stratification method was proposed according to the strongest predictors of mortality and MAEs on multivariable analysis.

RESULTS

The 30-day mortality, 90-day mortality, and MAE rates were 2.0%, 5.6%, and 20%, respectively. The independent predictors of 90-day mortality were chronic obstructive pulmonary disease, chronic kidney disease, ASA score, and LPMA. The independent predictors of MAEs were aneurysm diameter, glomerular filtration rate, and LPMA. For long-term mortality, the independent predictors were chronic kidney disease, congestive heart failure, extent I-III thoracoabdominal aortic aneurysms, ASA score, and LPMA. The patients were stratified into three groups according to the ASA score and LPMA: low risk, ASA score II or LPMA >350 cm²HU (n = 290); medium risk, ASA score III and LPMA ≤350 cm²HU (n = 181); and high risk, ASA score IV and LPMA ≤350 cm²HU (n = 33). The 90-day mortality and MAE rates were 1.7% and 16% in the low-, 7.2% and 24% in the medium-, and 30% and 33% in the high-risk patients, respectively (P < .001 and P = .02, respectively). Patients with ASA score IV and LPMA <200 cm²HU, indicating sarcopenia (n = 14) had a 43% risk of death within 90 days. The 3-year survival estimates were 80% ± 3% for the low-, 70% ± 4% for the medium-, and 35% ± 9% for the high-risk patients (P < .001). The mean follow-up time was 3.1 ± 2.3 years.

CONCLUSIONS

LPMA was a strong predictor of outcomes and the only independent predictor of both mortality and MAEs after FBEVAR. A high muscle mass was protective against complications, regardless of the ASA score. Risk stratification based on the ASA score and LPMA can be used to identify patients at excessively high operative risk.

Evolving Utility of Endovascular Treatment of Juxtarenal, Pararenal, and Suprarenal Abdominal Aortic Aneurysms Associated With Increased Risk of Mortality Over Time

BACKGROUND

Continued advances in endovascular technologies are resulting in fewer open abdominal aortic aneurysm (AAA) repairs. In addition, more complex juxtarenal, pararenal, and suprarenal (JPS) AAAs are being managed with various endovascular techniques. This study sought to evaluate the evolving trends in endovascular aneurysm repair (EVAR) of AAAs, hypothesizing increased rate of JPS AAA repair by EVAR. We also sought to evaluate the risk for morbidity and mortality for EVAR and open aneurysm repair (OAR) of JPS AAAs over time.

METHODS

The 2011-2017 American College of Surgeons National Surgical Quality Improvement Program Procedure-Targeted Vascular database was queried for patients undergoing OAR or EVAR for AAAs. A multivariable logistic regression analysis was performed for both infrarenal and JPS AAA repairs.

RESULTS

Of 18,661 patients who underwent AAA repair, 3,941 (21.1%) were OAR and 14,720 (78.9%) were EVAR. The rate of OAR decreased from 29.5% in 2011 to 21.3% in 2017 (P < 0.001) with a geometric-mean-annual decrease of 27.8%. The rate of EVAR increased from 70.5% to 78.7% during the same time period (P < 0.001) with a geometric-mean-annual increase of 11.6%. These trends remained true for both infrarenal and JPS AAAs. After adjusting for covariates, there was no difference in associated risk of 30-day mortality, renal complications, or ischemic colitis for either OAR or EVAR over each incremental year for infrarenal AAAs (P > 0.05). However, in patients undergoing EVAR for JPS AAAs, the associated risk of mortality increased with each incremental year (odds ratio [OR]: 1.30, confidence interval [CI]: 1.01-1.69, P = 0.039), whereas there was no difference in the risk of mortality for OAR of JPS AAAs with each incremental year (OR: 1.11, CI: 0.99-1.23, P = 0.067).

CONCLUSIONS

The rate of OAR for AAA has decreased over the past seven years with an increase in EVAR, particularly for more complex JPS AAAs. The associated risk for morbidity and mortality for treatment of infrarenal AAAs was not significantly affected by this increased utility of EVAR. The associated risk of mortality for JPS AAAs treated by EVAR increased over time, whereas this trend for associated risk of mortality was not seen for OAR of JPS AAAs. These findings, especially the increased associated risk of mortality over time with EVAR for JPS AAAs, warrant careful prospective analysis.

Midterm survival after endovascular repair of intact abdominal aortic aneurysms is improving over time

OBJECTIVE

There is a growing body of literature raising concerns about the long-term durability of endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAAs), suggesting that long-term outcomes may be better after open AAA repair. However, the data investigating these long-term outcomes largely originate from early in the endovascular era and therefore do not account for increasing clinical experience and technologic improvements. We investigated whether 4-year outcomes after EVAR and open repair have improved over time.

METHODS

We identified all EVARs and open repairs for intact infrarenal AAA within the Vascular Quality Initiative database (2003-2018). We then stratified patients by procedure year into treatment cohorts of four years: 2003-2006, 2007-2010, 2011-2014, and 2015-2018. We used Kaplan-Meier analysis and Cox proportional hazards models to assess whether the survival after EVAR or open repair changed over time. In addition, we propensity matched EVAR and open repairs for each time cohort to investigate whether the relative survival benefit of EVAR over open repair changed over time.

RESULTS

We included 42,293 EVARs (increasing from 549 performed between 2003 and 2006 to 25,433 between 2015 and 2018) and 5189 open AAA repairs (increasing from 561 to 2306). Four-year survival increased for the periods 2003-2006, 2007-2010, 2011-2014, and 2015-2018 after both EVAR (76.6% vs 79.7% vs 83.5% vs 87.3%; P < .001) and open repair (82.2% vs 85.8% vs 87.7% vs 88.9%; P = .026). After risk adjustment, compared with 2003-2006, hazard of mortality up to 4 years after EVAR was lower for those performed between 2011 and 2014 (hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.59-0.87; P = .001) and for those performed between 2015 and 2018 (HR, 0.56; 95% CI, 0.46-0.68; P < .001). In contrast, the risk-adjusted hazard of mortality was similar between open repair cohorts (2011-2014: HR, 0.81 [95% CI, 0.61-1.08; P = .15]; and 2015-2018: HR, 0.86 [95% CI, 0.64-1.17; P = .34]). Finally, in matched EVAR and open repairs, there was no difference in mortality in the first three cohorts, whereas the hazard of mortality was lower for the 2015-2018 cohort (HR, 0.65; 95% CI, 0.51-0.84; P = .001).

CONCLUSIONS

Four-year survival improved in more recent years after EVAR but not after open repair. This finding suggests that midterm outcomes after EVAR are improving, perhaps because of technologic improvements and increased experience, information that should be considered by surgeons and policymakers alike in evaluating the value of contemporary EVAR and open AAA repair.

A comparison of administrative data and quality improvement registries for abdominal aortic aneurysm repair

OBJECTIVE

Databases are essential in evaluating surgical outcomes and gauging the implementation of new techniques. However, there are important differences in how data from administrative databases and surgical quality improvement (QI) registries are collected and interpreted. Therefore, we aimed to compare trends, demographics, and outcomes of open and endovascular abdominal aortic aneurysm (AAA) repair in an administrative database and two QI registries.

METHODS

We identified patients undergoing open and endovascular repair of intact and ruptured AAAs between 2012 and 2015 within the National Inpatient Sample (NIS), the National Surgical Quality Improvement Program (NSQIP), and the Vascular Quality Initiative (VQI). We described the differences and trends in overall AAA repairs for each data set. Moreover, patient demographics, comorbidities, mortality, and complications were compared between the data sets using Pearson χ² test.

RESULTS

A total of 140,240 NIS patients, 10,898 NSQIP patients, and 26,794 VQI patients were included. Ruptured repairs composed 8.7% of NIS, 11% of NSQIP, and 7.9% of VQI. Endovascular aneurysm repair (EVAR) rates for intact repair (range, 83%-84%) and ruptured repair (range, 51%-59%) were similar in the three databases. In general, rates of comorbidities were lower in NIS than in the QI registries. After intact EVAR, in-hospital mortality rates were similar in all three databases (NIS 0.8%, NSQIP 1.0%, and VQI 0.8%; P = .06). However, after intact open repair and ruptured repair, in-hospital mortality was highest in NIS and lowest in VQI (intact open: NIS 5.4%, NSQIP 4.7%, and VQI 3.5% [P < .001]; ruptured EVAR: NIS 24%, NSQIP 20%, and VQI 16% [P < .001]; ruptured open: NIS 36%, NSQIP 31%, and VQI 26% [P < .001]). After stratification by intact and ruptured presentation and repair strategy, several discrepancies in morbidity rates remained between the databases. Overall, the number of cases in NSQIP represents 7% to 8% of the repairs in NIS, and the number of cases in VQI grew from 12% in 2012 to represent 23% of the national sample in 2015.

CONCLUSIONS

NIS had the largest number of patients as it represents the nationwide experience and is an essential tool to evaluate trends over time. The lower in-hospital mortality seen in NSQIP and VQI questions the generalizability of the studies that use these QI registries. However, with a growing number of hospitals engaging in granular QI initiatives, these QI registries provide a valuable resource to potentially improve the quality of care provided to all patients.

Surgery for small asymptomatic abdominal aortic aneurysms

BACKGROUND

An abdominal aortic aneurysm (AAA) is an abnormal ballooning of the major abdominal artery. Some AAAs present as emergencies and require surgery; others remain asymptomatic. Treatment of asymptomatic AAAs depends on many factors, but the size of the aneurysm is important, as risk of rupture increases with aneurysm size. Large asymptomatic AAAs (greater than 5.5 cm in diameter) are usually repaired surgically; very small AAAs (less than 4.0 cm diameter) are monitored with ultrasonography. Debate continues over the roles of early repair versus surveillance with repair on subsequent enlargement in people with asymptomatic AAAs of 4.0 cm to 5.5 cm diameter. This is the fourth update of the review first published in 1999.

OBJECTIVES

To compare mortality and costs, as well as quality of life and aneurysm rupture as secondary outcomes, following early surgical repair versus routine ultrasound surveillance in people with asymptomatic AAAs between 4.0 cm and 5.5 cm in diameter.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, two other databases, and two trials registers to 10 July 2019. We handsearched conference proceedings and checked reference lists of relevant studies.

SELECTION CRITERIA

We included randomised controlled trials where people with asymptomatic AAAs of 4.0 cm to 5.5 cm were randomly allocated to early repair or imaging-based surveillance at least every six months. Outcomes had to include mortality or survival.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted data, which were cross-checked by other team members. Outcomes were mortality, costs, quality of life, and aneurysm rupture. For mortality, we estimated risk ratios (RR) (endovascular aneurysm repair only), hazard ratios (HR) (open repair only), and 95% confidence intervals (CI) based on Mantel-Haenszel Chi² statistics at one and six years (open repair only) following randomisation.

MAIN RESULTS

We found no new studies for this update. Four trials with 3314 participants fulfilled the inclusion criteria. Two trials compared early open repair with surveillance and two trials compared early endovascular repair (EVAR) with surveillance. We used GRADE to access the certainty of the evidence for mortality and cost, which ranged from high to low. We downgraded the certainty in the evidence from high to moderate and low due to risk of bias concerns and imprecision (some outcomes were only reported by one study). All four trials showed an early survival benefit in the surveillance group (due to 30-day operative mortality with repair) but no evidence of differences in long-term survival. One study compared early open repair with surveillance with an adjusted HR of 0.88 (95% CI 0.75 to 1.02, mean follow-up 10 years; HR 1.21, 95% CI 0.95 to 1.54, mean follow-up 4.9 years). Pooled analysis of participant-level data from the two trials comparing early open repair with surveillance (maximum follow-up seven to eight years) showed no evidence of a difference in survival (propensity score-adjusted HR 0.99, 95% CI 0.83 to 1.18; 2226 participants; high-certainty evidence). This lack of treatment effect did not vary to three years by AAA diameter (P = 0.39), participant age (P = 0.61), or for women (HR 0.84, 95% CI 0.62 to 1.11). Two studies compared EVAR with surveillance and there was no evidence of a survival benefit for early EVAR at 12 months (RR 1.92, 95% CI 0.73 to 5.06; 846 participants; low-certainty evidence). Two trials reported costs. The mean UK health service costs per participant over the first 18 months after randomisation were higher in the open repair surgery than the surveillance group (GBP 4978 in the repair group versus GBP 3914 in the surveillance group; mean difference (MD) GBP 1064, 95% CI 796 to 1332; 1090 participants; moderate-certainty evidence). There was a similar difference after 12 years. The mean USA hospital costs for participants at six months after randomisation were higher in the EVAR group than in the surveillance group (USD 33,471 with repair versus USD 5520 with surveillance; MD USD 27,951, 95% CI 25,156 to 30,746; 614 participants; low-certainty evidence). After four years, there was no evidence of a difference in total medical costs between groups (USD 48,669 with repair versus USD 46,112 with surveillance; MD USD 2557, 95% CI -8043 to 13,156; 614 participants; low-certainty evidence). All studies reported quality of life but used different assessment measurements and results were conflicting. All four studies reported aneurysm rupture. There were very few ruptures reported in the trials of EVAR versus surveillance up to three years. In the trials of open surgery versus surveillance, there were ruptures to at least six years and there were more ruptures in the surveillance group, but most of these ruptures occurred in aneurysms that had exceeded the threshold for surgical repair.

AUTHORS' CONCLUSIONS

There was no evidence of an advantage to early repair for small AAA (4.0 cm to 5.5 cm), regardless of whether open repair or EVAR is used and, at least for open repair, regardless of patient age and AAA diameter. Thus, neither early open nor early EVAR of small AAAs is supported by currently available evidence. Long-term data from the two trials investigating EVAR are not available, so, we can only draw firm conclusions regarding outcomes after the first few years for open repair. Research regarding the risks related to and management of small AAAs in ethnic minorities and women is urgently needed, as data regarding these populations are lacking.

Early Detection of Undiagnosed Abdominal Aortic Aneurysm and Sub-Aneurysmal Aortic Dilatations in Patients with High-Risk Coronary Artery Disease: The Value of Targetted Screening Programme

INTRODUCTION

Abdominal aortic aneurysm (AAA) and coronary artery disease (CAD) share common risk factors. The objective of this study was to determine the prevalence of undiagnosed AAA in patients with angiographically diagnosed significant CAD.

PATIENTS AND METHODS

Male patients aged 50 years and above (including indigenous people) with angiographically diagnosed significant CAD in the recent one year were screened for AAA. Standard definition of abdominal aortic aneurysm and CAD was used. All new patients were followed up for six months for AAA events (ruptured AAA and AAA-related mortality).

RESULTS

A total of 277 male patients were recruited into this study. The total prevalence of undiagnosed AAA in this study population was 1.1% (95% CI 0.2-3.1). In patients with high-risk CAD, the prevalence of undiagnosed AAA was 1.7% (95% CI 0.3-4.8). The detected aneurysms ranged in size from 35.0mm to 63.8mm. Obesity was a common factor in these patients. There were no AAA-related mortality or morbidity during the follow-up. Although the total prevalence of undiagnosed AAA is low in the studied population, the prevalence of sub-aneurysmal aortic dilatation in patients with significant CAD was high at 6.6% (95% CI 3.9-10.2), in which majority were within the younger age group than 65 years old.

CONCLUSION

This was the first study on the prevalence of undiagnosed AAA in a significant CAD population involving indigenous people in the island of Borneo. Targeted screening of patients with high-risk CAD even though they are younger than 65 years old effectively discover potentially harmful asymptomatic AAA and sub-aneurysmal aortic dilatations.

The Safety of EVAS Surgical Conversion in a Comparative Monocentric Analysis

BACKGROUND

Endovascular aneurysm sealing (EVAS) was a widespread technology to treat abdominal aortic aneurysm. However, the particular morphology and structure of this endoprosthesis predisposed to proximal sealing defects with a high rate of reintervention or conversion to open surgery treatments. The purpose of this article is to report our experience on late open conversion of Nellix device, compared with the previous reported experience.

MATERIALS AND METHODS

Between September 2013 and February 2020, eight late open surgical conversions for endoleak (EL) were performed in our center: four of these were for EVAR. Four of these were EVAS devices required explantation and were included in the study. All excisions of infected abdominal aortic endograft were excluded.

RESULTS

All patients were treated within the original instructions for use. Aorto-bi-iliac reconstruction was performed with a bifurcated Dacron graft in all the four cases. At 12 months Doppler ultrasonography follow-up, good results at short term with preserved primary patency and freedom of re-intervention in three cases were reported. Only one patient died 16 days after the procedure. Nevertheless, the endoprosthetic structure allows in three of our cases to clamp down the renal level, with a decrease of the time of lower limbs ischemia and greater safety of the open surgery repair procedure.

CONCLUSIONS

The EVAS conversion is common, and a closer follow-up is required. The most recurrent open surgery indication is its migration and the EL type 1. The procedure is influenced by multiple comorbidities; emergency graft excision appears to increase morbidity and mortality, compared with elective surgical setting.

Value of Routine Flexible Sigmoidoscopy and Potential Predictive Factors for Colonic Ischemia after Open Ruptured Abdominal Aortic Aneurysm Repair

Background and Objectives: colonic ischemia (CI) after ruptured abdominal aortic aneurysm (rAAA) repair is associated with increased morbidity and mortality. CI may be detected by using flexible sigmoidoscopy, but routine use of flexible sigmoidoscopy after rAAA is not clearly proven. The objective of this study was to evaluate the efficacy of routine flexible sigmoidoscopy in detecting CI after rAAA repair, and to identify potential hemodynamic, biochemical, and clinical variables that can predict the development of CI in the patients who underwent rAAA surgery. Materials and Methods: we retrospectively included all rAAA cases treated in Viborg hospital from 1 April 2014 until 31 August 2017, recorded the findings on flexible sigmoidoscopy, and the incidence of CI. We collected specific hemodynamic, biochemical, and clinical variables, measured pre- and perioperatively, and the first three postoperative days. The association between CI and possible predictors was analyzed in a logistic regression model. Results: a total of 80 patients underwent open rAAA repair during the study period. Flexible sigmoidoscopy was performed in 58 of 80 patients (73.5%) who survived at least 24 h after open rAAA surgery. Perioperative variables lowest arterial pH (p = 0.02) and types of operations—aortobifemoral bypass vs. straight graft (p = 0.04) showed statistically significant differences between CI groups. The analysis of the postoperative variables showed statistically significant difference in highest lactate on postoperative day 1 (p = 0.01), and lowest hemoglobin on postoperative day 2 (p = 0.04) comparing CI groups. Logistic regression model revealed that postoperative hemoglobin and lactate turned out to be independent risk factors for the development of CI (respectively OR = 0.44 (95% CI = 0.29–0.67) and OR = 1.91 (95% CI = 1.2–3.05)). Conclusions: flexible sigmoidoscopy can identify patients being at higher risk of mortality after open rAAA repair. The postoperative lactate and hemoglobin were found to be independent risk factors for the development of CI after open rAAA repair. Further larger studies are warranted to demonstrate these findings.

Meta-analysis of phase-specific survival after elective endovascular versus surgical repair of abdominal aortic aneurysm from randomized controlled trials and propensity score-matched studies

OBJECTIVE

Although endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) significantly decreases perioperative mortality compared with open surgical repair (OSR), we have not concluded superiority between EVAR and OSR beyond the perioperative period. The aim of this study was to compare phase-specific survival after EVAR vs OSR.

METHODS

The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. Embase and MEDLINE were searched up to November 2019 to identify randomized controlled trials and propensity score-matched studies that investigated ≥2-year all-cause mortality (primary outcome) after EVAR vs OSR for intact infrarenal AAA. For each study, the hazard ratio (HR) with 95% confidence interval (CI) of mortality for EVAR vs OSR was calculated using survival curves for the following specific phases: early term (0-2 years after repair), midterm (2-6 years after repair), long term (6-10 years after repair), and very long term (≥10 years after repair). The risk ratio (RR) in the perioperative (in-hospital or 30-day) period was also extracted. Phase-specific HRs or RRs were separately pooled using the random effects model. Sensitivity analyses were performed by removing one study at a time to confirm that our findings were not derived from any single study. Funnel plot asymmetry was also examined using the linear regression test.

RESULTS

Our search identified four randomized controlled trials and seven propensity score-matched studies enrolling a total of 106,243 AAA patients assigned to EVAR (n = 53,123) or OSR (n = 53,120). The mortality after EVAR compared with OSR was significantly lower in the perioperative period (RR, 0.39; 95% CI, 0.29-0.51; P < .00001) and similar in the early-term period (HR, 0.93; 95% CI, 0.84-1.03; P = .16). Notably, significantly higher mortality was observed in the EVAR group compared with the OSR group in the midterm period (HR, 1.15; 95% CI, 1.03-1.29; P = .01). However, similar mortality was observed between the EVAR group and the OSR group in the long-term (HR, 1.06; 95% CI, 0.96-1.17; P = .27) and very-long-term (HR, 1.17; 95% CI, 0.93-1.47; P = .19) periods. In sensitivity analyses, the significant benefit of EVAR in the perioperative period and that of OSR in the midterm period were not changed. No funnel plot asymmetry was identified in all analyses.

CONCLUSIONS

Compared with OSR, EVAR was associated with lower perioperative mortality and higher mortality in the midterm period for intact infrarenal AAA. The superiority of EVAR was absent in the early-term period, and the inferiority of EVAR in the midterm period disappeared in the long-term and very-long-term periods.

Predictors of Survival in Patients Over 80 Years Old Treated with Fenestrated and Branched Endograft

BACKGROUND

Fenestrated and branched endovascular aneurysm repair endograft (f/bEVAR) allows the endovascular repair of thoracoabdominal and juxtarenal and pararenal abdominal aortic aneurysms (T-J-P-AAAs); however, given their high cost and complexity, their use should be limited to patients with life expectancy >2 years. Nevertheless, the number of patients older than 80 years treated by f/bEVAR is growing, with no hard evidence of the real efficacy in this context. The aim of the present study is to analyze the survival of ≥80-year-old patients treated with f/bEVAR, and to identify possible predictors of late mortality.

METHODS

An analysis of clinical, anatomical, and technical characteristics of patients treated with f/bEVAR for J-, P-, and T-AAA from 2010 to 2019 in a single academic center was performed. Follow-up data were collected prospectively with clinical visit and computed tomography angiography at discharge, after 6 months, and yearly thereafter. Survival after 2 years was evaluated by Kaplan-Meier analysis. Possible predictors of mortality were evaluated by univariable/multivariable analysis.

RESULTS

In the study period, a total of 243 f/bEVARs were considered: 83 for TAAA (34%) and 160 for J/PAAA (66%). Mean age was 73 ± 6 years, with 35 (14%) patients ≥80 years old; 209 patients (86%) were male and 78 (39%) had an American Society of Anesthesiology score IV. The 30-day and 2-year survival were 96% and 80 ± 3%, respectively. At a mean follow-up of 36 ± 25 months, independent predictors of late mortality by Cox regression analysis were chronic obstructive pulmonary disease (COPD), chronic renal failure (CRF), and ≥80 years old (hazard ratio [HR] 1.8, 95% confidence interval [CI] 1.02-3.2, P = 0.05; HR 1.7, 95% CI 1.01-3.4, P = 0.04; HR 3.1, 95% CI 1.5-6.3, P = 0.002, respectively). Preoperative clinical characteristics were similar in ≥80 years old versus younger patients, except for the prevalence of TAAA (14% vs. 38%, P = 0.04). The technical success and 30-day mortality were similar in ≥80 vs. <80-year-old patients (93% vs. 96%, P = 0.31; 7% vs. 3.5%, P = 0.60, respectively). The 2-year survival estimation was significantly lower in ≥80 years old compared with younger patients (62 ± 10% vs. 82 ± 3%, P = 0.003). The association of COPD and CRF significantly affects the 2-year survival in ≥80-year-old patients (no patients survived at 2 years) and was significantly different compared with the survival in ≥80-year-old patients without these risk factors (70 ± 11%, P = 0.001).

CONCLUSIONS

The early mortality rate and the 2-year survival after f/bEVAR justify this type of treatment in patients ≥80 years old; however, the presence of comorbidities such as COPD and CRF significantly reduces mid-term survival in this group and should be taken into consideration in the indication to f/bEVAR.

Female sex is associated with comparable 5-year outcomes after contemporary endovascular aneurysm repair despite more challenging anatomy

BACKGROUND

Women with abdominal aortic aneurysms less often meet anatomic criteria for endovascular repair and experience worse perioperative and long-term survival.

METHODS

We compared long-term survival, aneurysm-related mortality, and rates of endoleaks and reinterventions between male and female patients in the Endurant Stent Graft Natural Selection Global Postmarket Registry (ENGAGE) using 2:1 propensity score matching.

RESULTS

There were 1130 male patients and 133 female patients, yielding 399 patients after matching (266 male patients, 133 female patients). Female patients were older, with smaller aneurysms, smaller iliac arteries, and shorter, more angulated necks, and they were more often treated outside the device instructions for use (all P < .001). Through 5 years, female patients experienced overall mortality comparable to that of well-matched male patients (34% vs 38%, respectively; hazard ratio, 0.89 [0.61-1.29]; P = .54) and lower aneurysm-related mortality (0% vs 3%; P = .047). Female patients experienced higher rates of any postoperative type IA endoleak through 5 years (10% vs 1%; P < .001) but comparable rates of secondary endovascular procedures (14% vs 16%; P = .40). Female sex was independently associated with significantly higher risk of long-term type IA endoleaks (hazard ratio, 4.8 [1.2-20.8]; P = .04), even after accounting for anatomic factors. No female patient experienced aneurysm rupture during follow-up, and only one female patient underwent conversion to open repair.

CONCLUSIONS

Despite more challenging anatomy, female patients in the ENGAGE registry had long-term outcomes comparable to those of male patients. However, female patients experienced higher rates of type IA endoleaks. Although standard endovascular aneurysm repair remains a viable solution for most women, whether high-risk patients may be better served with open surgery, custom-made devices, EndoAnchors (Aptus Endosystems, Sunnyvale, Calif), or chimneys is worthy of further study.

Overall outcome after endovascular aneurysm repair with a first-generation stent graft (Vanguard): A 20-year single-center experience

OBJECTIVE

The problems with first-generation stent grafts for endovascular aneurysm repair are well known, but their long-term outcome remains to be established. The purpose of the study was to characterize the outcome of patients treated for abdominal aortic aneurysm (AAA) with a first-generation stent graft, Vanguard (Boston Scientific, Natick, Mass), in a single academic center with a follow-up of up to 20 years.

METHODS

There were 48 AAA patients electively treated with a Vanguard stent graft between February 1997 and November 1999. The patients were monitored annually until the end of 2018. The outcomes were overall survival and the number of graft-related complications and reinterventions.

RESULTS

The mean age was 70 years (range, 54-85 years), and the mean follow-up was 107 months (range, 6-262 months). All stent grafts were successfully implanted, but 90% of the patients encountered graft-related complications during follow-up. The most common complications were endoleaks (type I, 27%; type II, 29%; type III, 31%), stent fracture (46%), graft thrombosis (31%), and migration (40%). A total of 40 (83%) patients required a secondary procedure during long-term follow-up. The endovascular method for treating the complication was successful in 73 (87%) of 84 cases. There were no primary conversions, but 10 patients (21%) required a late conversion. In five cases, the complications required relining with a newer device. There were four AAA ruptures (8.3%), two of them fatal. The cumulative overall survival rates were 94%, 69%, 33%, 15%, and 13% at 1 year, 5 years, 10 years, 15 years, and 20 years, respectively.

CONCLUSIONS

The use of the Vanguard, a first-generation stent graft, was associated with multiple graft-related complications. However, these complications could mainly be treated by endovascular means. The Vanguard stent graft is a good example of how new technology can cause unpredictable problems that can magnify the workload and endanger the patient's well-being even decades after the initial procedure.

Survival After Uncomplicated EVAR in Octogenarians is Similar to the General Population of Octogenarians Without an Abdominal Aortic Aneurysm

OBJECTIVE

Long term survival after endovascular aortic aneurysm repair (EVAR) in octogenarians remains unclear. This was evaluated by comparing octogenarians after EVAR with a matched group of octogenarians without an abdominal aortic aneurysm (AAA) from the Rotterdam Study (RS). The influence of complications after EVAR on survival was also studied with the aim of identifying risk factors for the development of complications in octogenarians.

METHODS

Using propensity score matching (PSM), 83 EVAR octogenarians were matched for comorbidities with 83 octogenarians from the RS, and survival was compared between these two groups using Cox proportional hazard analysis. Then, complications were studied, defined as cardiac or pulmonary, renal deterioration, access site bleeding, acute limb ischaemia or bowel ischaemia, within 30 days of surgery between 83 EVAR octogenarians and 475 EVAR non-octogenarians. Also, the difference in baseline characteristics between the octogenarians with and without complications after EVAR were studied, and survival was compared between the RS controls and the complicated and uncomplicated EVAR octogenarians separately.

RESULTS

The total EVAR octogenarian population did not show an increased mortality risk compared with RS octogenarian controls (hazard ratio [HR] 1.28, 95% confidence interval [CI] 0.84-1.97). Post-operative complications occurred in 22 octogenarians (27%) and 59 non-octogenarians (12.4%, p < .001), mainly cardiac, pulmonary, and bleeding complications. All baseline characteristics were similar in the complicated EVAR octogenarians compared with the uncomplicated EVAR octogenarians. After uncomplicated EVAR, octogenarians had a similar survival compared with the RS controls (HR 1.09, 95% CI 0.68-1.77), but after complicated EVAR their mortality risk increased significantly (HR 1.93, 95% CI 1.06-3.54).

CONCLUSION

After standard EVAR, the life expectancy of octogenarians is the same as that of a matched group from the general population without an AAA, provided they do not develop early post-operative complications. Patient selection and meticulous peri-operative care are key.

Postoperative surveillance and long-term outcome after endovascular aortic aneurysm repair in the Netherlands: study protocol for the retrospective ODYSSEUS study

INTRODUCTION

Strict imaging surveillance protocols to detect complications following endovascular aneurysm repair (EVAR) are common practice. However, controversy exists as to whether all EVAR patients need intense surveillance. The 2019 European Society for Vascular Surgery guidelines for management of abdominal aortic aneurysm (AAA) suggest that patients may be considered for limited follow-up with imaging if classified as 'low risk' for complications based on their initial postoperative imaging. The current study aims to investigate the intervention-free survival and overall survival stratified for patients with and without yearly imaging surveillance.

METHODS AND ANALYSIS

The Observing a Decade of Yearly Standardised Surveillance in EVAR patients with Ultrasound or CT Scan study comprises a national multicentre retrospective cohort study in 17 medical centres. Consecutive patients with an asymptomatic or symptomatic infrarenal AAA who underwent EVAR between January 2007 and January 2012 will be included in this study with follow-up until December 2018. Clinical variables and all follow-up information will be retrieved in extensive data collection from the patient's medical records. In addition, an e-survey was sent to vascular surgeons at the 17 participating centres to gauge their opinions regarding the possibility of safely reducing the frequency of imaging surveillance. Primary endpoints are intervention after EVAR and aneurysm-related mortality. The initial estimated sample size is 1997 patients.

ETHICS AND DISSEMINATION

The study has been approved by the Medical Ethics Review Committee of the Amsterdam UMC, location Academic Medical Centre, Amsterdam, the Netherlands. Study findings will be disseminated via presentations at conferences and publications in peer-reviewed journal.

TRIAL REGISTRATION NUMBER

The Netherlands Trial Registry, NL6953 (old: NTR28773).

Elevated neutrophil-lymphocyte ratio predicts mortality following elective endovascular aneurysm repair

OBJECTIVE

The neutrophil-lymphocyte ratio (NLR) is an inexpensive and useful inflammatory marker that incorporates the balance of the innate (neutrophil) and adaptive (lymphocyte) immune responses. Data exist on the association between NLR and mortality in various coronary diseases and in cancer surgery, but there is a paucity of data on the impact of preoperative NLR on vascular surgical outcomes. The aim of this study was to evaluate the relationship between preoperative NLR and elective endovascular aortic aneurysm repair (EVAR) outcome.

METHODS

A retrospective review of all patients who underwent elective EVAR at a single institution between 2010 and 2018 was conducted (n = 373). Only patients who had a preoperative complete blood count with differential within 30 days of their operation were included. The NLR was computed by dividing the absolute neutrophil count by the absolute lymphocyte count. A receiver operating characteristic curve was used to determine the optimal cutoff value of NLR with the strongest association with mortality. NLR was dichotomized so that patients with NLR above the threshold were at increased risk of mortality compared with those below it. Continuous variables were analyzed using Wilcoxon nonparametric signed-rank test and categorical variables with the Fisher exact test. A comparison of NLR and mortality was completed using Kaplan-Meier survival analysis. Cox regression analysis was used to evaluate factors associated with mortality through 5-year follow-up.

RESULTS

Overall, 108 patients were included in this study. An NLR ≥ 4.0 was found to be associated with mortality (P < .0001). Thirty-two patients composed the High-NLR (NLR ≥ 4.0) group and the remaining 76 patients formed the Low-NLR (NLR < 4.0) group. Baseline characteristics were similar between groups, except that the High-NLR group was older (77.9 vs 74.4; P = .047). At a mean of 36.4 months follow-up, the overall mortality rate was 32.4%. Although there were no differences in the perioperative period, the Kaplan-Meier estimates of mortality were significantly greater in the High-NLR group at 1, 2, and 5 years postoperatively (P < .0001). The mean preoperative NLR of the deceased was higher (5.94 ± 5.20; median, 4.75; interquartile range, 3.17-7.83) than those who survived (2.87 ± 1.61; median, 2.53; interquartile range, 1.97-3.49) (P < .0001). Secondary interventions and sac enlargement rates were similar between groups. On univariable analysis, NLR (hazard ratio [HR], 1.17; 95% confidence interval [CI], 1.10-1.23; P < .0001), age (HR, 1.06; 95% CI, 1.02-1.11; P = .004), and aneurysm diameter (HR, 1.04; 95% CI, 1.01-1.07; P = .003) were associated with mortality. On multivariable analysis, NLR (HR, 1.19; 95% CI, 1.12-1.27; P < .0001), age (HR, 1.06; 95% CI, 1.01-1.11; P = .026), and aneurysm diameter (HR, 1.04; 95% CI, 1.02-1.07; P = .003) were associated with mortality.

CONCLUSIONS

Patients with an elevated preoperative NLR, irrespective of other comorbidities, may represent a previously unrecognized subset of patients who are at heightened risk of mortality after elective EVAR. A complete blood count with differential is an inexpensive test that may be used as a prognostic indicator for outcome after EVAR. Further research is warranted to identify clinical, pathological, or anatomical factors associated with an elevated NLR and to determine modifiable factors, which may help improve long-term survival.

Association of Sex With Repair Type and Long-term Mortality in Adults With Abdominal Aortic Aneurysm

IMPORTANCE

Sex-based differences exist in the prevalence and clinical presentation of abdominal aortic aneurysm (AAA). However, it is unclear if sex is associated with AAA repair type and long-term mortality.

OBJECTIVE

To investigate whether a sex-related difference exists in mortality risk after AAA repair owing to differences in repair type.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study uses data from the Vascular Quality Initiative, a national clinical registry, and Medicare claims to investigate endovascular and surgical repair procedures performed between January 1, 2003, and September 30, 2015, in patients aged 65 years or older with AAA. The data were analyzed from October 1, 2018, to November 19, 2019.

EXPOSURE

Sex of the patient.

MAIN OUTCOMES AND MEASURES

Endovascular (EVR) or open surgical AAA repair type and subsequent long-term, all-cause mortality.

RESULTS

In this cohort study of 16 386 patients, 12 757 (77.9%) were men and 3629 (22.1%) were women. Women were more likely than men to be older (mean [SD] age, 77 [6.5] years vs 75 [6.6] years; P < .001), active smokers (33% vs 28%; P < .001), and to have smaller aneurysms (mean [SD] diameter, 57 [11.7] mm vs 59 [17.7] mm; P < .001). Surgical AAA repair was performed in 27% (983 of 3629) of women compared with 18% (2328 of 12 757) of men (P < .001). After inverse probability weighting for risk adjustment, women were more likely to receive open surgical repair than EVR repair (risk ratio, 1.65; 95% CI, 1.51-1.80). The 10-year unadjusted survival rate after EVR repair was 14% lower in women than in men (23% vs 37%; log-rank P < .001), but the rates were comparable after open surgical repair (36% in men vs 32% in women; log-rank P = .22). Risk-adjusted analysis showed that women were associated with higher mortality rates after EVR repair (hazard ratio, 1.13; 95% CI, 1.03-1.24), whereas both men and women had a similar risk of death after open surgical repair (hazard ratio, 0.94; 95% CI, 0.84-1.06). After further stratification by symptom severity, higher risk of mortality among women was limited to elective EVR and open surgical repair for ruptured AAA.

CONCLUSIONS AND RELEVANCE

In this study, women were 65% more likely than men to undergo open surgical repair. After EVR repair, women were 13% more likely to die than men, although no sex-based difference in mortality was found after open surgical repair. The differential treatment benefit of EVR repair in women is concerning given the shift toward an EVR-first approach to AAA repair.

Endovascular Aneurysm Sealing is Associated with Higher Medium-Term Survival than Traditional EVAR

BACKGROUND

Endovascular aneurysm repair (EVAR) is the dominant treatment modality for abdominal aortic aneurysm (AAA). Periprocedural risks are low, and cardiovascular events are the principle determinants of long-term survival. Recently, the concept of endovascular aneurysm sealing (EVAS) has been introduced into clinical investigation. In previous cohort studies, EVAS has been associated with a lower all-cause mortality than expected despite device issues. We used a propensity weighted approach to investigate whether EVAS was associated with lower all-cause mortality after aneurysm repair.

METHODS

We compared 333 patients in the Nellix United States Investigational Device Exemption trial to 15,431 controls from the Vascular Quality Initiative between 2014 and 2016 after applying the exclusion criteria from the investigational device exemption (hemodialysis, creatinine > 2.0 mg/dL, or rupture). We calculated propensity scores and applied inverse probability weighting to compare risk adjusted medium-term survival using Kaplan-Meier and Cox regression.

RESULTS

After weighting, patients treated with the Nellix EVAS system experienced higher 3-year survival than controls from the Vascular Quality Initiative (93% vs. 88%, respectively). This corresponded to a 41% lower risk of mortality for EVAS compared with EVAR (HR 0.59 [0.38-0.92], P = 0.02). Subgroup analysis demonstrated that the association between EVAS and higher survival was strongest in the subgroup of patients with aneurysms over 5.5 cm (P for interaction < 0.001). In this subgroup, EVAS patients experienced half the rate of mortality as those patients treated with EVAR, with 3-year survival of 92% compared with 86% (HR 0.5 [0.3-0.9], P = 0.02).

CONCLUSIONS

In this select group of patients, EVAS was associated with higher medium-term survival than traditional EVAR. Although issues with the device have recently surfaced, this exploratory analysis shows that the concept of sac sealing may hold promise. Further study is needed to confirm this finding and determine whether EVAS is associated with lower rates of cardiovascular events.

LUCY results show females have equivalent outcomes to males following endovascular abdominal aortic aneurysm repair despite more complex aortic morphology

OBJECTIVE

Females remain underrepresented in studies of endovascular aneurysm repair (EVAR) owing to anatomic ineligibility for EVAR devices. The aim of the LUCY study is to explore the comparative safety and effectiveness of EVAR using a low-profile stent graft (Ovation; Endologix, Inc, Irvine, Calif) in females as well as males.

METHODS

The LUCY registry was a prospective, nonrandomized, multicenter study where patient enrollment was stratified by sex in a two-to-one ratio (male-to-female). Main outcomes were procedural data, 30-day major adverse events, device-related adverse events confirmed with contrast-enhanced computed tomography scans, secondary interventions, and hospital readmissions. Adverse events were adjudicated by a clinical events committee. Patients were followed at their 1-month and 1-year follow-up visits.

RESULTS

A total of 225 patients (76 females, 149 males) were enrolled at 39 U.S. centers. No statistically significant sex differences were observed in demographics or medical history. Females presented with smaller access vessels (6.2 vs 7.7 mm; P < .001), statistically smaller neck diameter (22 mm vs 23 mm; P = .001), similar neck angulation (11% vs 9% angulation >45°; P = .81), and smaller maximum abdominal aortic aneurysm (AAA) diameter (50 mm vs 53 mm; P = .01), however, these factors do not seem to be clinically significant. Technical success was 99%, and the median hospital stay was 1 day. The incidence of MAE through 30 days was 1.3% in females and 2.0% in males. There were no differences between sexes observed among the 30-day perioperative outcomes. The 30-day secondary intervention rate was 0.4%. The all-cause readmission rate through 30 days was 5.3% in females and 6.7% in males. There were no reports of limb occlusion or deaths within the first 30 days. At 1 year, there were no deaths in the female arm but nine deaths (6.0%) were observed in males, two of which were AAA related (1.3%). Through 1 year, there were eight type IA endoleaks (one female, seven males; P = .27) and three cases with limb occlusion (one female, two males). There were no reports of migration, AAA rupture, or surgical conversion through the end of follow-up.

CONCLUSIONS

Despite more complex aortic morphology in females than males, EVAR with a low-profile stent graft was associated with comparable procedural and perioperative outcomes through 1 year between the sexes.