Long-term survival after endovascular and open repair of unruptured abdominal aortic aneurysm

Editor's Choice - External Validation of a Prognostic Model for Survival of Patients With Abdominal Aortic Aneurysms Treated by Endovascular Aneurysm Repair

OBJECTIVE

Current guidelines recommend diameter monitoring of small and asymptomatic abdominal aortic aneurysms (AAAs) due to the low risk of rupture. Elective AAA repair is recommended for diameters ≥ 5.5 cm in men and ≥ 5.0 cm in women. However, data supporting the efficacy of elective treatment for all patients above these thresholds are diverging. For a subgroup of patients, life expectancy might be very short, and elective AAA repair at the current threshold may not be justified. This study aimed to externally validate a predictive model for survival of patients with an asymptomatic AAA treated by endovascular aneurysm repair (EVAR).

METHODS

This was a multicentre international retrospective observational cohort study. Data were collected from four European aortic centres treating patients between 2001 and 2021. The initial model included age, estimated glomerular filtration rate (eGFR), and chronic obstructive pulmonary disease (COPD) as independent predictors for survival. Model performance was measured by discrimination and calibration.

RESULTS

The validation cohort included 1 500 patients with a median follow up of 65 months, during which 54.6% of the patients died. The external validation showed slightly decreased discrimination ability and signs of overfitting in model calibration. However, a high risk subgroup of patients with impaired survival rates was identified: octogenarians with eGFR < 60 OR COPD, septuagenarians with eGFR < 30, and septuagenarians with eGFR < 60 and COPD having survival rates of only 55.2% and 15.5% at five and 10 years, respectively.

CONCLUSION

EVAR is a valuable treatment option for AAA, especially for patients unsuitable for open repair. Nonetheless, not all these patients will benefit from EVAR, and an individualised treatment recommendation should include considerations on life expectancy. This study provides a risk stratification to identify patients who may not benefit from EVAR using the present diameter thresholds.

Association of polypharmacy scores with the long-term survival of patients with intact aortoiliac aneurysms and indication for repair

OBJECTIVE/BACKGROUND

Our study analyzed the relationship between two polypharmacy scores (addition of chronic prescribed drugs [ACPDs] and Rx-Risk Comorbidity Index) and survival in patients with an intact abdominal aortic and/or common iliac aneurysm (AAA).

METHODS

Consecutive retrospective, single-center cohort of patients attended for an intact AAA with indication for repair from 2008 to 2021. Demographic data, Charlson Comorbidity Index, AAA treatment, ACPD, and Rx-Risk polypharmacy scores were recorded at baseline. Main outcomes were the 5-year and long-term survival rates. The statistical analysis included Cox regression, area under the curve, and continuous net reclassification index.

RESULTS

A total of 424 patients with AAA were evaluated (median age: 76 years; 92.2% male, median Charlson index 2), of whom 314 (74.1%) underwent intervention (80% endovascular and 20% open) and 110 (25.9%) did not. During follow-up (mean 4.6 years), 245 patients (57.8%) died, with 1-month, 1-year, and 5-year survival rates of 98.1%, 86.3%, and 52.7%, respectively. ACPD and Rx-Risk indices (median [interquartile range]: 6 [4-9] and 3 [0-5], respectively) were significantly and linearly associated (P < .001) with survival, with the best cutoff points at 5 and 0, respectively. An ACPD >5 (patients with >5 chronically prescribed drugs at baseline) and an Rx-Risk >0 were associated with a 45.2% (P = .038) and 102% (P = .002) increase in 5-year mortality, respectively, after adjustment for age, sex, Charlson index, and type of AAA treatment. Both polypharmacy indices improved significantly the discriminative power of the Charlson Comorbidity Index in predicting survival.

CONCLUSIONS

Both ACPD and Rx-Risk polypharmacy scores are independently related to survival among patients with an intact AAA and indication for repair. Their behavior is similar, so the simple ACPD >5 appears to be sufficient to identify patients with lower survival rates.

Effects of abdominal aortic aneurysm on long-term survival in lung cancer patients

The major causes of death in patients with abdominal aortic aneurysm (AAA) are cardiovascular disease and cancer. The purpose of this study was to evaluate the effect of AAA on long-term survival in lung cancer patients. All patient data with degenerative type AAA and lung cancer over 50 years of age during the period 2009 to 2018 was collected retrospectively from a National Health Insurance Service (NHIS) administrative database and matched to lung cancer patients without AAA by age, sex, metastasis, and other comorbidities. Mortality rate was compared between the groups. A total of 956 AAA patients who could be matched with patients without AAA were included, and 3824 patients in the matched group were used for comparison. Patients with AAA showed higher risk of death compared with the matched cohort (adjusted hazard ratio (HR) 1.14, 95% confidence interval (CI) 1.06-1.23, p < 0.001). When compared to a matched group of untreated AAA patients, patients with of history of AAA exhibited a significantly increased risk of overall mortality [HR (95%CI) 1.219 (1.113-1.335), p < .001, adjusted HR (95% CI) 1.177 (1.073-1.291), p = .001]. By contrast, mortality risk of AAA patients treated either by endovascular abdominal aortic repair or open surgical repair was not significantly different from that of the matched group (p = 0.079 and p = 0.625, respectively). The mortality risk was significantly higher when AAA was present in lung cancer patients, especially in patients with unrepaired AAA, suggesting the need for continuous cardiovascular risk management.

Association of women-specific size threshold and mortality in elective abdominal aortic aneurysm repair

BACKGROUND

It is unclear whether women derive mortality benefit from early repair of abdominal aortic aneurysms (AAA). The aim of this study was to compare short- and mid-term mortality for women treated at small versus large diameters.

METHOD

Women receiving elective repair of AAA at small (49-54 mm) and large (≥55 mm) diameters from 2008 to 2022 were extracted from the Swedish National Registry for Vascular Surgery (n = 1642 women). The effect of diameter on 90-day, 1- and 3-year mortality was studied in logistic regression and propensity score models. Age, co-morbidities, smoking and repair modality were considered as confounders. Men (n = 9047) were analysed in parallel.

RESULTS

Some 1642 women were analysed, of whom 34% underwent repair at small diameters (versus 52% of men). Women with small (versus large) AAAs were younger (73 versus 75 years, P < 0.001), and 63% of women in both size groups had endovascular repairs (P = 0.120). Mortality was 3.5% (90 days), 7.1% (1 year) and 15.8% (3 years), with no differences between the size strata. There was no consistent association between AAA size and mortality in multivariable models. Sex differences in mortality were almost entirely due to mortality in younger-than-average women versus men (3-year mortality: small AAAs 11.1% versus 7.3%, P < 0.030, or large 14.4% versus 10.7%, P < 0.038).

CONCLUSION

Mortality in women is high and unaffected by AAA size at repair. The optimal threshold for women remains undefined. The higher rupture risk in women should not automatically translate into a lower, women-specific threshold.

Long-Term Outcomes of Open Versus Endovascular Treatment for Abdominal Aortic Aneurysm: Systematic Review and Meta-Analysis With Reconstructed Time-to-Event Data

BACKGROUND

The advent of endovascular techniques has revolutionized the care of patients with uncomplicated abdominal aortic aneurysms. This analysis compares the overall survival and the freedom from reintervention rate between open surgical repair (OSR) and endovascular repair (EVAR) in patients undergoing elective abdominal aortic aneurysm (AAA) repair.

METHODS

PubMed, Scopus, and Cochrane databases were searched for studies including patients who underwent either OSR or EVAR for uncomplicated AAA. All randomized controlled trials and propensity-score-matched cohort studies reporting on the outcomes of interest were considered eligible for inclusion. The systematic search of the literature was performed by 2 independent investigators in accordance with the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. We conducted 1-stage and 2-stage meta-analyses with Kaplan-Meier-derived time-to-event data and meta-analysis with a random-effects model.

RESULTS

Thirteen studies met our eligibility criteria, incorporating 13 409 and 13 450 patients in the OSR and EVAR arms, respectively. Patients who underwent open repair had improved overall survival rates compared with those who underwent EVAR (hazard ratio [HR]=0.93, 95% confidence interval [CI]=0.88-0.98, p=0.004) during a mean follow-up of 53.8 (SD=29.8) months and this was validated by the 2-stage meta-analysis (HR=0.89, 95% CI=0.8-0.99, p=0.03, I2=62.25%). Splitting timepoint analysis suggested that EVAR offers better survival outcome compared with OSR in the first 11 months following elective intervention (HR=1.37, 95% CI=1.22-1.54, p<0.0001), while OSR offers a significant survival advantage after the 11-month timepoint and up to 180 months (HR=0.84, 95% CI=0.8-0.89, p<0.0001). Similarly, freedom from reintervention was found to be significantly better in EVAR patients (HR=1.28, 95% CI=1.14-1.44, p<0.0001) within the first 30 days. After the first month postrepair, however, OSR demonstrated higher freedom-from-reintervention rates compared with EVAR that remained significant for up to 168 months during follow-up (HR=0.73, 95% CI=0.66-0.79, p<0.0001).

CONCLUSIONS

Despite the first-year survival advantage of EVAR in patients undergoing elective AAA repair, OSR was associated with a late survival benefit and decreased risk for reintervention in long-term follow-up.

CLINICAL IMPACT

Open surgical repair for uncomplicated abdominal aortic aneurysm offers better long-term outcomes in terms of survival and freedom from reintervention rate compared to the endovascular approach but in the first year it carries a higher risk of mortality. The novelty of our study lies that instead of comparing study-level effect estimates, we analyzed reconstructed individual patient-level data. This offered us the opportunity to perform our analyses with mathematically robust and flexible survival models, which was proved to be crucial since there was evidence of different hazard over time. Our findings underline the need for additional investigation to clarify the significance of open surgical repair when compared to the latest endovascular devices and techniques within the evolving era of minimally invasive procedures.

Semi-Conservative Treatment Versus Radical Surgery in Abdominal Aortic Graft and Endograft Infections

OBJECTIVE

Abdominal aortic graft and endograft infections (AGIs) are rare complications following aortic surgery. Radical surgery (RS) with resection of the infected graft and reconstruction with extra-anatomical bypass or in situ reconstruction is the preferred therapy. For patients unfit for RS, a semi-conservative (SC), graft preserving strategy is possible. This paper aimed to compare survival and infection outcomes between RS and SC treatment for AGI in a nationwide cohort.

METHODS

Patients with abdominal AGI related surgery in Sweden between January 1995 and May 2017 were identified. The Management of Aortic Graft Infection Collaboration (MAGIC) criteria were used for the definition of AGI. Multivariable regression was performed to identify factors associated with mortality.

RESULTS

One hundred and sixty-nine patients with surgically treated abdominal AGI were identified, comprising 43 SC (14 endografts; 53% with a graft enteric fistula [GEF] in total) and 126 RS (26 endografts; 50% with a GEF in total). The SC cohort was older and had a higher frequency of cardiac comorbidities. There was a non-significant trend towards lower Kaplan-Meier estimated five year survival for SC vs. RS (30.2% vs. 48.4%; p = .066). A non-significant trend was identified towards worse Kaplan-Meier estimated five year survival for SC patients with a GEF vs. without a GEF (21.7% vs. 40.1%; p = .097). There were significantly more recurrent graft infections comparing SC with RS (45.4% vs. 19.3%; p < .001). In a Cox regression model adjusting for confounders, there was no difference in five year survival comparing SC vs. RS (HR 1.0, 95% CI 0.6 - 1.5).

CONCLUSION

In this national AGI cohort, there was no mortality difference comparing SC and RS for AGI when adjusting for comorbidities. Presence of GEF probably negatively impacts survival outcomes of SC patients. Rates of recurrent infection remain high for SC treated patients.

Long-term Mortality and Reintervention After Endovascular and Open Abdominal Aortic Aneurysm Repairs in Australia, Germany, and the United States

OBJECTIVE

To examine long-term outcomes after endovascular (EVAR) and open repairs (OAR) for intact abdominal aortic aneurysms in Australia, Germany, and the United States, using a unified study design.

BACKGROUND

Similarities and differences in long-term outcomes after EVAR versus OAR across countries remained unclear, given differences in designs across existing studies.

METHODS

We identified patients aged >65 years undergoing intact abdominal aortic aneurysm repairs during 2010-2017/2018. We compared long-term patient mortality and reintervention after EVAR and OAR using Kaplan-Meier analyses and Cox regressions. Propensity score matching was performed within each country to adjust for differences in baseline patient characteristics between procedure groups.

RESULTS

We included 3311, 4909, and 145363 patients from Australia, Germany, and the United States, respectively. The median patient age was 76 to 77 years, and most patients were males (77%-84%). Patient mortality was lower after EVAR than OAR within the first 60 days and became similar at 3-year follow-up (Australia 14.7% vs 16.5%, Germany 18.2% vs 19.7%, United States: 24.4% vs 24.4%). At the end of follow-up, patient mortality after EVAR was higher than OAR in Australia [ hazard ratio (HR) 95% CI: 1.21 (0.96-1.54)] but similar to OAR in Germany [HR 95% CI: 0.92 (0.80-1.07)] and the United States [HR 95% CI: 1.02 (0.99-1.05)]. The risk of reintervention after EVAR was more than twice that after OAR in Australia [HR 95% CI: 2.60 (1.09-6.15)], Germany [HR 95% CI: 4.79 (2.56-8.98)], and the United States [HR 95% CI: 2.67 (2.38-3.00)]. The difference in reintervention risk appeared early in German and United States patients.

CONCLUSIONS

This multinational study demonstrated important similarities in long-term outcomes after EVAR versus OAR across 3 countries. Variation in long-term mortality and reintervention comparisons indicates possible differences in patient profiles, surveillance, and best medical therapy across countries.

Long-Term Outcomes Following Elective Repair of Intact Abdominal Aortic Aneurysms: A Comparison Between Open Surgical and Endovascular Repair Using Linked Administrative and Clinical Registry Data

OBJECTIVE

Compare long-term mortality, secondary intervention and secondary rupture following elective endovascular aneurysm repair (EVAR) and open surgical repair (OSR).

BACKGROUND

EVAR has surpassed OSR as the most common procedure used to repair abdominal aortic aneurysm (AAA), but evidence regarding long-term outcomes is inconclusive.

METHODS

We included patients in linked clinical registry and administrative data undergoing EVAR or OSR for intact AAA between January 2010 and June 2019. We used an inverse probability of treatment-weighted survival analysis to compare all-cause mortality, cause-specific mortality, secondary interventions and secondary rupture, and evaluate the impact of secondary interventions and secondary rupture on all-cause mortality.

RESULTS

The study included 3460 EVAR and 427 OSR patients. Compared to OSR, the EVAR all-cause mortality rate was lower in the first 30 days [adjusted hazard ratio (HR) = 0.22, 95% confidence interval (CI) 0.140.33], but higher between 1 and 4 years (HR = 1.29, 95% CI 1.12-1.48) and after 4years (HR = 1.41, 95% CI 1.23-1.63). Secondary intervention rates were higher over the first 30 days (HR = 2.26, 95% CI 1.11-4.59), but lower between 1 and 4years (HR = 0.59, 95% CI 0.48-0.74). Secondary aortic intervention rates were higher across the entire follow-up period (HR = 2.52, 95% CI 2.06-3.07). Secondary rupture rates did not differ significantly (HR = 1.06, 95% CI 0.73-1.55). All-cause mortality beyond 1 year remained significantly higher for EVAR after adjusting for any secondary interventions, or secendary rupture.

CONCLUSIONS

EVAR has an early survival benefit compared to OSR. However, elevated long-term mortality and higher rates of secondary aortic interventions and subsequent aneurysm repair suggest that EVAR may be a less durable method of aortic aneurysm exclusion.

Comparative performance of three comorbidity scores in predicting survival after the elective repair of abdominal aortic aneurysms

BACKGROUND

We aimed to study the discriminative power of 3 comorbidity scores for predicting 5-year survival after the elective repair of aorto-iliac aneurysms (AAA).

METHODS

444 patients with AAA undergoing elective repair (33% open and 67% endovascular) between 2000 and 2020 were reviewed. The Charlson Comorbidity Index (CCI) and subsequent adjustments by Schneeweiss, Quan and Armitage, the Modified Frailty Index (MFI) and the American Society of Anesthesiologists Score (ASA) were calculated from preoperative data. Their association with 5-year survival was analyzed using Cox regression models and their discriminative power and its changes with C statistics and Net Reclassification Index (NRI).

RESULTS

All comorbidity scores were associated with survival after adjusting by age, sex and type of surgical repair: original CCI HR=1.24, P<0.001; Schneeweiss CCI HR=1.23, P<0.001; Quan CCI HR=1.27, P<0.001, Armitage CCI HR=1.46, P<0.001, MFI HR=1.39, P<0.001 and ASA HR=1.68 (P=0.04) and 2.86 (P=0.01) for classes III and IV, respectively. Associated C statistics were of 0.64, 0.65, 0.65, 0.64, 0.61 and 0.59, respectively. Compared with the original CCI, models based on Schneeweiss CCI and Armitage CCI provided minor improvements in NRI (0.32 and 0.23), and the model based on ASA showed lower C statistics (P=0.014) and NRI (-0.30).

CONCLUSIONS

Established comorbidity scores, such as CCI, MFI or ASA, are all associated with 5-year survival after the elective repair of AAAs, being ASA the worst of them. However, their predictive power is in no case sufficient to identify, by themselves, those patients who may not be eligible for intervention on the basis of life expectancy.

Prognostic model for survival of patients with abdominal aortic aneurysms treated with endovascular aneurysm repair

The role of endovascular aneurysm repair (EVAR) in patients with asymptomatic abdominal aortic aneurysm (AAA) who are unfit for open surgical repair has been questioned. The impending risk of aneurysm rupture, the risk of elective repair, and the life expectancy must be balanced when considering elective AAA repair. This retrospective observational cohort study included all consecutive patients treated with standard EVAR for AAA at a referral centre between 2001 and 2020. A previously published predictive model for survival after EVAR in patients treated between 2001 and 2012 was temporally validated using patients treated at the same institution between 2013 and 2020 and updated using the overall cohort. 558 patients (91.2% males, mean age 74.9 years) were included. Older age, lower eGFR, and COPD were independent predictors for impaired survival. A risk score showed good discrimination between four risk groups (Harrel's C = 0.70). The 5-years survival probabilities were only 40% in "high-risk" patients, 68% in "moderate-to-high-risk" patients, 83% in "low-to-moderate-risk", and 89% in "low-risk" patients. Low-risk patients with a favourable life expectancy are likely to benefit from EVAR, while high-risk patients with a short life expectancy may not benefit from EVAR at the current diameter threshold.

Long-term outcome and cancer incidence after abdominal aortic aneurysm repair

Purpose

The influence of cancer development on long-term outcome after elective endovascular (EVAR) vs. open repair (OAR) of non-ruptured abdominal aortic aneurysms (AAA) was investigated.

Methods

Patient survival and cancer incidence were recorded for 18,802 patients registered with the AOK health insurance company in Germany who underwent EVAR (n = 14,218) and OAR (n = 4584) in the years 2010 to 2016 (men n = 16,086, women n = 2716). All patients were preoperatively and in their history cancer-free.

Results

30.1% of EVAR and 27.6% of OAR patients (p ≤ .001) developed cancer after a follow-up period of up to 9 years (Kaplan–Meier estimated). Patients with cancer had a significantly less favorable outcome compared to patients with no cancer (HR 1.68; 95% CI 1.59–1.78, p < .001). After 9 years, the estimated survival of patients with and without cancer was 27.0% and 55.4%, respectively (p < .001). Survival of men and women did not differ significantly (HR 0.94; 95% CI 0.88–1.00, p = .061). In the Cox regression analysis (adjusted outcomes by operative approach, gender, age, and comorbidities), the postoperative cancer incidence was not significantly different between EVAR and OAR (HR 1.09; 95% CI 1.00–1.18, p = .051). However, EVAR showed an increased risk of postoperative development of abdominal cancer (HR 1.20; 95% CI 1.07–1.35, p = .002). 48.0% of all EVAR patients and 53.4% of all OAR patients survived in the follow-up period of up to 9 years. This difference was not significant (HR 0.96; 95% CI 0.91–1.02, p = .219).

Conclusion

Cancer significantly worsened the long-term outcome after EVAR and OAR, without significant differences between the two repair methods in the overall cancer incidence. However, the higher abdominal cancer incidence with EVAR can affect quality of life including oncological therapy and therefore should be considered when determining the indication for surgery, and the patient should be informed about it.

The Association Between Preoperative Independent Ambulatory Status and Outcomes After Open Abdominal Aortic Aneurysm Repairs

OBJECTIVE

Preoperative functional status is appreciated as a key determinant of decision-making when evaluating patients for complex elective surgeries. We used the Vascular Quality Initiative (VQI) to analyze the effect of being able to independently ambulate on outcomes after open abdominal aortic aneurysm (AAA) repairs.

METHODS

We identified all patients who underwent elective or urgent open AAA repairs from January 2013 to August 2019 in the VQI registry. We recorded demographic variables, comorbidities, and operative factors such as approach, operative ischemia time, proximal clamp site, and presence of iliac aneurysms. Short-term and long-term outcomes included 30-day mortality, any perioperative complications, failure to rescue (defined as death after a complication), and one-year all-cause mortality. We dichotomized patients based on their ability to independently ambulate (Ambulatory) or inability to ambulate independently (Non-Ambulatory) and used both multivariable logistic regressions and cox-proportional hazards models to evaluate outcomes.

RESULTS

Of 5,371 patients, 328 (6.1%) could not ambulate independently and were more likely to be older (median age 69 vs 72), female (25% vs. 38%), and have greater comorbidities. Overall outcomes were: 4.3% for 30-day mortality, 38.7% for complications, 10.2% for failure-to-rescue, and 6.9% for one-year mortality. Univariate analysis showed higher rates of all adverse outcomes in non-ambulatory patients. On adjusted analysis, non-ambulatory patients had increased odds of complications by 46% (OR 1.46 [95%-CI 1.11-1.91]) and one-year mortality by 46% (HR 1.46 [95%-CI 1.06-1.99]), but not failure to rescue (OR 1.05 [95%-CI 0.67-1.62]) or 30-day mortality (OR 1.22 [95%-CI 0.82-1.81]). Increased hospital volume, age, and increased operative renal ischemia time were independently associated with adverse outcomes.

CONCLUSIONS

Non-ambulatory status was observed in a small percentage of patients undergoing open AAA repair but was associated with higher rates of post-operative complications and one-year mortality. Ambulatory capacity is one of the key determinants of outcomes following open AAA repair. In patients with poor ambulatory function, a conservative approach is highly recommended over invasive open surgical intervention.

Nationwide study in France investigating the impact of diabetes on mortality in patients undergoing abdominal aortic aneurysm repair

The aim of this nationwide study was to analyze the impact of diabetes on post-operative mortality in patients undergoing AAA repair in France. This 10-year retrospective, multicenter study based on the French National electronic health data included patients undergoing AAA repair between 2010 and 2019. In-hospital post-operative mortality was analyzed using Kaplan–Meier curve survival and Log-Rank tests. A multivariate regression analysis was performed to calculate Hazard Ratios. Over 79,935 patients who underwent AAA repair, 61,146 patients (76.5%) had at least one hospital-readmission after the AAA repair, for a mean follow-up of 3.5 ± 2.5 years. Total in-hospital mortality over the 10-year study was 16,986 (21.3%) and 4581 deaths (5.8%) occurred during the first hospital stay for AAA repair. Age over 64 years old, the presence of AAA rupture and hospital readmission at 30-day were predictors of post-operative mortality (AdjHR = 1.59 CI 95% 1.51–1.67; AdjHR = 1.49 CI 95% 1.36–1.62 and AdjHR = 1.92, CI 95% 1.84–2.00). The prevalence of diabetes was significantly lower in ruptured AAA compared to unruptured AAA (14.8% vs 20.9%, P < 0.001 for type 2 diabetes and 2.5% vs 4.0%, P < 0.001 for type 1 diabetes). Type 1 diabetes was significantly associated with post-operative mortality (AdjHR = 1.30 CI 95% 1.20–1.40). For type 2 diabetes, the association was not statistically significant (Adj HR = 0.96, CI 95% 0.92–1.01). Older age, AAA rupture and hospital readmission were associated with deaths that occurred after discharge from the first AAA repair. Type 1 diabetes was identified as a risk factor of post-operative mortality. This study highlights the complex association between diabetes and AAA and should encourage institutions to report long-term follow-up after AAA repair to better understand its impact.

Effect of the SARS-CoV-2 pandemic on mortality related to high-risk emergency and major elective surgery

These data show large reductions in both elective and emergency activity that are concerning for unmeasured morbidity and mortality within the community. The risk of mortality following high-risk EGS and major elective surgery during the first wave of the pandemic did not differ when compared with date-matched patient cohorts from 2019. The prevalence of concomitant SARS-CoV-2 infection in this surgical population is low.

Comparison of peak wall stress and peak wall rupture index in ruptured and asymptomatic intact abdominal aortic aneurysms

BACKGROUND

Previous studies have suggested that finite element analysis (FEA) can estimate the rupture risk of an abdominal aortic aneurysm (AAA); however, the value of biomechanical estimates over measurement of AAA diameter alone remains unclear. This study aimed to compare peak wall stress (PWS) and peak wall rupture index (PWRI) in participants with ruptured and asymptomatic intact AAAs.

METHODS

The reproducibility of semiautomated methods for estimating aortic PWS and PWRI from CT images was assessed. PWS and PWRI were estimated in people with ruptured AAAs and those with asymptomatic intact AAAs matched by orthogonal diameter on a 1 : 2 basis. Spearman's correlation coefficient was used to assess the association between PWS or PWRI and AAA diameter. Independent associations between PWS or PWRI and AAA rupture were identified by means of logistic regression analyses.

RESULTS

Twenty individuals were included in the analysis of reproducibility. The main analysis included 50 patients with an intact AAA and 25 with a ruptured AAA. Median orthogonal diameter was similar in ruptured and intact AAAs (82·3 (i.q.r. 73·5-92·0) versus 81·0 (73·2-92·4) mm respectively; P = 0·906). Median PWS values were 286·8 (220·2-329·6) and 245·8 (215·2-302·3) kPa respectively (P = 0·192). There was no significant difference in PWRI between the two groups (P = 0·982). PWS and PWRI correlated positively with orthogonal diameter (both P < 0·001). Participants with high PWS, but not PWRI, were more likely to have a ruptured AAA after adjusting for potential confounders (odds ratio 5·84, 95 per cent c.i. 1·22 to 27·95; P = 0·027). This association was not maintained in all sensitivity analyses.

CONCLUSION

High aortic PWS had an inconsistent association with greater odds of aneurysm rupture in patients with a large AAA.

Editor's Choice - Variation in Intact Abdominal Aortic Aneurysm Repair Outcomes by Country: Analysis of International Consortium of Vascular Registries 2010 - 2016

OBJECTIVE

Outcomes for intact abdominal aortic aneurysm (AAA) repair vary over time and by healthcare system, country, and surgeon. The aim of this study was to analyse peri-operative mortality for intact AAA repair in 11 countries over time and compare outcomes by gender, age, and geographical location.

METHODS

Prospective data on primary repair of intact AAA were collected from 11 countries through the International Consortium of Vascular Registries (ICVR) and analysed for two time periods, 2010 - 2013 and 2014 - 2016. The primary outcome was peri-operative mortality after endovascular aneurysm repair (EVAR) and open surgical repair (OSR). Multivariable logistic regression models were used to adjust for differences in patient characteristics.

RESULTS

A total of 103 715 patients were included. The percentage of patients undergoing EVAR increased from 63.6% to 71.2% (p < .001) over the study period. This proportion varied by country from 35% in Hungary to 81% in the United States. Overall peri-operative mortality decreased from 2.1% to 1.6 % (p < .001). Mortality also declined significantly over time for both OSR 4.2% to 3.6 % (p = .002) and EVAR 1.0% to 0.7% (p = .002). Mortality was significantly higher for female than male patients (3.0% vs. 1.6% p < .001). The percentage of patients > 80 years old undergoing AAA repair remained constant at 23.6% (p = .91). Peri-operative mortality was higher for patients > 80 years than for those < 80 years old (2.7% vs. 1.6% p < .001). Forty-six per cent (n = 275) of all EVAR deaths occurred in the over 80s.

CONCLUSION

The proportion of AAA repairs performed using EVAR has increased over time. Peri-operative mortality continues to decline for both OSR and EVAR. Outcomes however were significantly worse for both women and those aged over 80, so efforts should be focused on these patient groups to further reduce elective AAA mortality rates.

Four-year results of the Bolton relay proximal scallop endograft in the management of thoracic and thoracoabdominal aortic pathology with unfavorable proximal landing zone

BACKGROUND

Thoracic endovascular aortic repair with a scallop design (scallop-TEVAR) is a useful treatment strategy to extend the proximal landing zone (PLZ), while maintaining perfusion to one or more of the supra-aortic trunks (SATs) when treating aortic pathology with an unfavorable PLZ. The durability of this approach with the Bolton Relay scallop endograft (Terumo Aortic, Sunrise, Fla) has not been established.

METHODS

A retrospective review of prospectively collected data on consecutive patients that received scallop-TEVAR in zones 0 to 2 at a tertiary aortic unit was undertaken. The main outcome was durability, characterized by survival estimates, freedom from reintervention to the thoracic aorta and PLZ, migration and aneurysm sac regression.

RESULTS

Between 2009 and 2019, 38 patients (71% male; median age, 70 years) underwent scallop-TEVAR for thoracic aortic pathology (n = 28, 74%) or as a part of thoracoabdominal aneurysm repair (n = 10 [26%]). The use of scallop-TEVAR significantly extended the PLZ (median, 5 mm preoperative PLZ vs 26 mm extended PLZ; P = .0001). A total of 41 SATs were perfused with a scallop, including the left subclavian artery (n = 25), left common carotid artery (n = 6), neo/innominate artery (n = 4), left subclavian artery, and vertebral artery (n = 1), innominate artery, and left common carotid artery (n = 2) in conjunction with 15 extra-anatomical bypasses. The PLZ was at Ishimaru zone 0 and 1 in 6 cases (16%), respectively, and zone 2 in 26 cases (68%). Technical success was 98%. The 30-day mortality was 5% (2/38; 1 death from myocardial infarction and 1 from multiorgan failure). A minor stroke occurred in three patients (8%) and temporary spinal cord ischemia in two patients (5%). The median follow-up was 4.5 years (range, 0-10.53 years) during which two patients (5%) developed type Ia endoleak and required intervention to the PLZ (one from device-related migration and one from disease progression). All-cause and aorta-related survival were 72% and 85% and freedom from thoracic and PLZ reintervention was 92% and 97%, respectively. There were no cases of early or late thoracic aortic rupture, retrograde type A aortic dissection or SAT occlusion.

CONCLUSIONS

Scallop-TEVAR offers a less invasive treatment option to extend the seal zone in selected patients with an unfavorable PLZ, allowing for a durable repair in terms of overall survival and reintervention. Periprocedural stroke remains a principle concern.

Progressive Device Failure at Long Term Follow Up of the Nellix EndoVascular Aneurysm Sealing (EVAS) System

OBJECTIVE

High rates of midterm failure of the Nellix EndoVascular Aneurysm Sealing (EVAS) System resulted in device withdrawal from the UK market. The study aim was to report long term Nellix EVAS outcomes and management of a failing device.

METHODS

A retrospective review of EVAS procedures at a tertiary unit was performed. Device failure was defined as a triad of stent migration, stent separation, and secondary sac expansion, or any intervention for type 1 endoleak, device rupture, or explant.

RESULTS

161 (male n = 140, female n = 21) patients with a median follow up of 6.0 (IQR 5.0-6.6) years were included. Freedom from all cause mortality estimate at six years was 41.5%. There were 70 (43.5%) device failures with a freedom from device failure estimate at six years of 32.3%. Failure was the result of sac expansion (n = 41), caudal stent migration (n = 36), stent separation (n = 26), and secondary AAA rupture (n = 15). A substantial number of type 1 endoleaks was present (1a n = 33, 1b n = 11), but the type 2 endoleak rate was low at 3.7%. Some 36 (22.4%) patients required re-intervention. Twenty-one patients underwent explant with no 30 day deaths. Six patients underwent Nellix-in-Nellix application (NINA) with one early death from bowel ischaemia and one patient who died later from non-aneurysm related cause. Two NINA patients have ongoing sac expansion and two have had thrombosis of a Nellix limb or visceral stent. Proximal embolisation was only successful in one of six cases.

CONCLUSION

The long term failure rate of Nellix EVAS is high. All patients with a device must be informed and be enrolled in enhanced surveillance. EVAS explant is an acceptable technique with favourable outcomes. Management by open explant, if the patient is fit, should be considered early and offered to those with device failure.

Abdominal aortic aneurysms part two: Surgical management, postoperative complications and surveillance

Large, symptomatic and ruptured abdominal aortic aneurysms are usually treated surgically if patients are deemed fit enough. This may be achieved through endovascular or open surgical repair. The type of treatment that a patient receives is dependant on many factors, such as the rupture status of the aneurysm. Each approach is also associated with different risks and postoperative complications. Multiple guidelines exist to inform the surgical management of abdominal aortic aneurysms. This literature review combines these recommendations and explores the evidence upon which they are based. In addition, it highlights the key perioperative considerations that need to be considered in cases of unruptured and ruptured abdominal aortic aneurysms.

Aneurysms and dissections - What is new in the literature of 2019/2020 - a European Society of Vascular Medicine annual review

More than 6,000 publications were found in PubMed concerning aneurysms and dissections, including those Epub ahead of print in 2019, printed in 2020. Among those publications 327 were selected and considered of particular interest.

Editor's Choice - Volume-Outcome Relationships in Elective Abdominal Aortic Aneurysm Surgery: Analysis of the UK Hospital Episodes Statistics Database for the Getting It Right First Time (GIRFT) Programme

OBJECTIVE

To investigate whether a volume-outcome relationship exists for elective abdominal aortic aneurysm (AAA) surgery conducted within the National Health Service (NHS) in England.

METHODS

This was an analysis of administrative data. Data were extracted from the Hospital Episodes Statistics database for England from April 2011 to March 2019 for all adult admissions for elective infrarenal AAA surgery. Data were extracted for the NHS trust and surgeon undertaking the procedure, the surgical technique used (open or endovascular), the financial year of admission, length of hospital and critical care stay during the procedure and subsequent emergency re-admissions (primary outcome) and deaths within 30 days. Multilevel modelling was used to adjust for hierarchy and confounding.

RESULTS

A dataset of 31 829 procedures (8867 open, 22 962 endovascular) was extracted. For open surgery, lower trust annual volume was associated with higher 30 day emergency re-admission rates and higher 30 day mortality. For open surgery, lower surgeon annual volume was associated with higher 30 day mortality and length of hospital stay greater than the median. For endovascular surgery, lower surgeon annual volume was associated with not having an overnight stay in critical care. None of the other volume-outcome relationships investigated was significant.

CONCLUSION

For elective infrarenal AAA surgery in the UK NHS, there was strong evidence of a volume-outcome relationship for open surgery. However, evidence for a volume-outcome relationship is dependent on the specific procedure undertaken and the outcome of interest.

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.