Editor's Choice - Post-operative Surveillance and Long Term Outcome after Endovascular Aortic Aneurysm Repair in Patients with an Initial Post-operative Computed Tomography Angiogram Without Abnormalities: the Multicentre Retrospective ODYSSEUS Study

Single Centre Evaluation of the Proposal of the European Society for Vascular Surgery Abdominal Aortic Aneurysm Guidelines to Stratify Surveillance after Endovascular Aortic Aneurysm Repair

OBJECTIVE

The aim of this study was to evaluate and compare methods that identify patients at low risk of developing complications after endovascular aortic aneurysm repair (EVAR) and who would thus not require surveillance in the first post-operative years.

METHODS

This was a retrospective, single centre, cohort study including all patients after elective infrarenal EVAR with both immediate post-operative and one year computed tomography angiography (CTA) imaging. Patients were categorised by adherence to instructions for use (IFU), adequate seal, and absence of endoleak (method A1), and without high risk features (method A2) on the first post-operative CTA. Additionally, these patients were dichotomised based on aneurysm sac shrinkage at one year (> 5 mm maximum diameter reduction, method B). Outcomes were graft related adverse events and all cause death. Negative predictive value (NPV) was used to compare risk classifications.

RESULTS

Of 422 eligible patients, 297 underwent the required imaging for classification: 140 (47.1%) and 109 (36.7%) patients were classified as low risk based on methods A1 and A2, respectively, while 147 (49.5%) were assumed low risk based on method B. The five year cumulative incidence of adverse events in low risk patients according to method A1 was 14.7% (95% confidence interval [CI] 8.5 - 20.9%), similar to method A2 (16.1%, 95% CI 8.8 - 23.4%) and method B (15.4%, 95% CI 9.3 - 21.5%). The five year median NPV for adverse events for method A1 was 85.2% (95% CI 79.7 - 90.8%), comparable with method A2 (83.8%, 95% CI 76.9 - 90.3%; p = .37) and method B (84.7%, 95% CI 79.4 - 89.5%; p = .87). Significantly higher NPVs were found by combining method A1 or A2 with method B, with median values ≥ 95% up to four years after EVAR. The five year NPV for death did not differ between methods (five year NPVmethod A1, 81.7%, 95% CI 76.6 - 86.5%).

CONCLUSION

Refraining from imaging in the first five years after EVAR in patients treated within IFU and with a favourable post-operative CTA would have failed to detect important complications at an early stage. It is proposed to combine the post-operative CTA with sac shrinkage at one year in order to stratify post-EVAR surveillance. No benefit was found in considering the high risk features suggested in the European Society for Vascular Surgery (ESVS) guidelines.

Proximity and prior medical engagement influence follow-up after ruptured abdominal aortic aneurysm

OBJECTIVE

Post-repair surveillance of ruptured abdominal aortic aneurysm (rAAA) is critical for detecting potential complications. Substantial loss to follow-up has been reported in populations undergoing elective endovascular aortic repair (EVAR); however, there is limited data on follow-up rate among patients presenting with rupture. Thus, we investigated follow-up trends and factors influencing retention at a major academic referral center with a wide service area.

METHODS

We included patients with rAAAs from 2002 through 2023 in this retrospective study. Loss to follow-up was defined as absence of vascular surgeon evaluation for 2 years (EVAR) or 5 years (open repair) prior to death or present day. Multivariate regression and survival models assessed the influence of potential factors on follow-up and survival outcomes.

RESULTS

Of 455 patients who presented with rAAAs, 60% who underwent EVAR and 39% who underwent open repair were lost to follow-up. Twenty percent of patients who underwent EVAR were lost after initial admission, and 40% of patients were lost after the 1-month postoperative follow-up visit. There were no significant differences in baseline demographics. Patients lost to follow-up less commonly had stage 4 chronic kidney disease (7.2% vs 24.3%; P = .02) and prior EVAR (10.0% vs 29.2%; P = .01) at time of rupture. Secondary interventions were less common in patients lost to follow-up (14.5% vs 39.0%; P = .01). In multivariate analysis of patients who underwent an EVAR, residing more than 10 miles from hospital was associated with loss to follow-up (odds ratio [OR], 4.93; 95% confidence interval [CI], 1.14-21.29). Prior endograft at time of rupture (OR, 0.24; 95% CI, 0.06-0.89), and estimated glomular filtration rate <30 mL/min/1.73m2 (OR, 0.23; 95% CI, 0.06-0.93) were associated with complete follow-up in patients who underwent EVAR. Patients who were lost to follow-up trended towards worse survival (hazard ratio, 2.04; 95% CI, 0.67-6.26), whereas prior endograft was associated with significantly worse survival after EVAR (hazard ratio, 3.11; 95% CI, 1.20-8.04).

CONCLUSIONS

Although most patients with rAAAs attend their 1-month postoperative visit, the majority are subsequently lost to follow-up. Geographic proximity to the hospital and higher baseline medical engagement, as indicated by prior endograft and chronic kidney disease, appeared to be protective against such loss. Targeted counseling and engagement at the 1-month postoperative visit, particularly in patients with less comorbid conditions, may enhance retention to long-term follow-up.

Secondary interventions and surveillance after elective abdominal aortic aneurysm repair

BACKGROUND

The early survival benefits of endovascular aneurysm repair (EVAR) appear to diminish over time, and late aneurysm-related mortality remains a significant concern. Our aim is to determine the rate of secondary interventions (SI) and assess compliance with post-EVAR surveillance.

METHODS

This retrospective cohort study included consecutive patients who underwent elective EVAR between February 2009 and May 2019 at a tertiary center. The primary outcomes were freedom from SI and compliance with follow-up (imaging performed within a time interval of no more than 18 months). Secondary outcome was overall patient survival.

RESULTS

A total of 214 patients underwent EVAR, with a median follow-up of 44 months. During this period, 42 SI were performed in 25 patients. Of all SI, 33.3% (14/42) were due to symptomatic complications. Freedom from SI was 96.3±1.3% at 30 days and 93.6±1.7%, 90.3±2.2% and 85.9±3.0 at 1, 3 and 5 years, respectively. Endoleaks were the main cause of SI after EVAR (N.=26), primarily type 1 and type 2. At 5 years, patient survival rates were similar (76.7±4.1% vs. 84.4±7.2%, P=0.386). Compliance with surveillance was 80.4±2.9% at 1 year, and 37.7±5.4% at 5 years.

CONCLUSIONS

SI after EVAR were frequent, with endoleaks being the leading cause and associated with cases of aneurysm sac rupture. Although compliance with surveillance decreases over longer follow-up periods, the impact of this trend on long-term outcomes after EVAR warrants further investigation.

The Impact of Neutrophil-to-Lymphocyte Ratio on Short- and Long-Term Prognosis Following Elective Infrarenal EVAR

BACKGROUND

Neutrophil-to-lymphocyte ratio (NLR) is a readily available parameter, associated with long-term outcomes in cardiovascular conditions. This study aims to analyze the predictors of NLR and its impact on prognosis and disease-specific outcomes following endovascular aneurysm repair (EVAR).

METHODS

Single-center retrospective cohort study. Consecutive patients who underwent elective EVAR (2011-2023) were considered. Primary outcome is short-term major adverse events (MAE) and long-term mortality. Secondary outcomes were freedom-from EVAR failure, aortic reintervention, and NLR predictors. Multivariable logistic regression analyses were performed for binary outcomes. Survival outcomes were analyzed through Kaplan-Meier and Cox regression analyses.

RESULTS

Overall, 434 patients were included. A 2.4 NLR cutoff was a fair discriminator for long-term-mortality (area under the curve, 0.62), and groups were dichotomized according to this premise. Increasing age (adjusted odds ratio [aOR]: 1.06; 1.03-1.09, per 1-year increase) and a pulmonary comorbidity (aOR: 1.91; 1.24-2.96) associated to NLR ≥ 2.4. No significant association between comorbidity burden and NLR was observed. MAE occurred more often if NLR ≥ 2.4 (6.2 vs. 11.6% high-NLR, P = 0.049; NLR ≥ 2.4 aOR: 2.10; 1.01-4.36). At 8-years follow-up, survival estimates favored NLR < 2.4 (55.7% vs. 33.7% high-NLR, P < 0.001, NLR ≥ 2.4 adjusted hazard ratio [aHR]: 1.07; 1.05-1.98), without differences in freedom-from EVAR failure (70.6 vs. 68.2% high-NLR, P = 0.27, NLR ≥ 2.4 aHR: 1.26; 0.82-1.94). Conversely, NLR ≥ 2.4 associated with lower freedom from aortic reinterventions (80.0% vs. 70.2% high-NLR, P = 0.01, NLR ≥ 2.4 aHR: 1.80; 1.08-3.01).

CONCLUSION

NLR appears as a prognostic marker with reduced impact of comorbidity burden. Following EVAR, it independently predicts MAE and mortality. Over time, elevated NLR appears associated with increased aortic reinterventions, although rates and mode of failure seem similar across groups.

An international, expert-based, Delphi consensus document on controversial issues in the management of abdominal aortic aneurysms

OBJECTIVE

As a result of conflicting, inadequate or controversial data in the literature, several issues concerning the management of patients with abdominal aortic aneurysms (AAAs) remain unanswered. The aim of this international, expert-based Delphi consensus document was to provide some guidance for clinicians on these controversial topics.

METHODS

A three-round Delphi consensus document was produced with 44 experts on 6 prespecified topics regarding the management of AAAs. All answers were provided anonymously. The response rate for each round was 100%.

RESULTS

Most participants (42 of 44 [95.4%]) agreed that a minimum case volume per year is essential (or probably essential) for a center to offer open or endovascular AAA repair (EVAR). Furthermore, 33 of 44 (75.0%) believed that AAA screening programs are (probably) still clinically effective and cost effective. Additionally, most panelists (36 of 44 [81.9%]) voted that surveillance after EVAR should be (or should probably be) lifelong. Finally, 35 of 44 participants (79.7%) thought that women smokers should (or should probably/possibly) be considered for screening at 65 years of age, similar to men. No consensus was achieved regarding lowering the threshold for AAA repair and the need for deep venous thrombosis prophylaxis in patients undergoing EVAR.

CONCLUSIONS

This expert-based Delphi consensus document provides guidance for clinicians regarding specific unresolved issues. Consensus could not be achieved on some topics, highlighting the need for further research in those areas.

Sealing Zone Failure Decreases the Long Term Durability of Endovascular Aneurysm Repair

OBJECTIVE

Endovascular aneurysm repair (EVAR) has a higher long term aneurysm related mortality rate compared with open surgery, mainly due to aneurysm rupture. Loss of stent graft to vessel apposition at the EVAR sealing zones is a potential cause of post-EVAR rupture. This study aimed to investigate sealing zone failure and its relationship with post-EVAR rupture.

METHODS

This was a retrospective structured review of pre- and post-operative computed tomography (CT) scans of 399 consecutive patients treated with standard bifurcated EVAR. The primary outcome was total loss of seal at last post-operative CT. Secondary outcomes were partial loss of seal, standard follow up detection, post-EVAR rupture, aneurysm sac development, and endoleaks.

RESULTS

During a median follow up of 5.3 years, total and partial loss of seal occurred in 85 (21.3%) and 78 (19.5%) patients, respectively. Initial mean sealing zone lengths were within current recommendations but decreased over time, mainly due to vessel dilatation. Mean proximal sealing length at the one month CT was 15.5 ± 10.5 mm (95% confidence interval [CI] 12.6 - 18.5 mm) in the group with total loss of seal, 14.3 ± 6.9 mm (95% CI 12.2 - 16.4 mm) with partial loss of seal, and 23.2 ± 7.4 mm (95% CI 22.3 - 24.0 mm) with preserved seal through follow up (p < .001). Mean iliac sealing lengths were 22.4 ± 12.1 mm (95% CI 18.9 - 25.8 mm) if total loss and 21.8 ± 10.0 mm (95% CI 19.6 - 24.0 mm) if partial loss of seal vs. 34.7 ± 12.4 mm (95% CI 33.8 - 35.7 mm) if preserved seal. Larger vessel diameters were associated with loss of seal in both the proximal and distal sealing zones. During the study period, 13 post-EVAR ruptures occurred, all preceded by CT findings of total (n = 7) or partial (n = 6) loss of seal. Aneurysm sac expansion was seen in 40% of patients with total loss of seal, 18% with partial loss of seal, and 6.6% with preserved seal.

CONCLUSION

Loss of seal after EVAR is frequent and associated with post-EVAR rupture. Increased recommended sealing zones lengths and focus on sealing zones in surveillance may reduce post-EVAR ruptures and aneurysm related death.

Potential of D-Dimer as a Tool to Rule Out Sac Expansion in Patients With Persistent Type 2 Endoleaks After Endovascular Aneurysm Repair

PURPOSE

In managing type 2 endoleak (T2EL) following endovascular aortic aneurysm repair (EVAR), an indication for reintervention is aneurysm enlargement (AnE). A previous study found that low D-dimer levels (DDLs) at 1 year were associated with reduced AnE risk in patients with persistent T2ELs (pT2ELs). This study analyzed patients with pT2ELs to determine the correlation between DDLs at annual follow-ups and AnE and proposed a follow-up protocol incorporating DDL monitoring.

METHODS

A retrospective review of elective EVAR cases between June 2007 and January 2021 identified "persistent" T2EL as confirmed at both 6- and 12-month contrast-enhanced CT studies. "Isolated" T2EL referred to cases without other endoleak types within 12 months. Inclusion criteria comprised >2 years of follow-up, isolated pT2ELs at 1 year, and DDL data at any annual follow-up over 5 years. The association between DDL and AnE, defined as ≥5 mm expansion within 5 years, was analyzed.

RESULTS

A total of 109 patients with DDL data at 288 time points were enrolled. During a median follow-up of 49 months [31-60, IQR], 43 AnE were observed. In patients without AnE and with DDL data at 1 and 2 years (N=77 and 56), lower DDLs were associated with a reduced AnE risk (p=0.03 and 0.01). Optimal cutoff points were 5.4 and 5.3 µg/mL (AUC=0.651 and 0.702) with high negative predictive values (86.9% and 93.8%). Cox regression analyses confirmed that DDLs surpassing the cutoff values correlated significantly with AnE (p=0.042 and p=0.038). Our simulated protocol for omitting imaging studies in patients with stable aneurysms and low DDL might have overlooked one AnE but could have saved 28 imaging studies over 3 years if implemented on our patients.

CONCLUSION

Low DDLs at the 1- and 2-year follow-ups can potentially exclude AnE in pT2EL patients, suggesting DDL monitoring as a resource-saving approach.

CLINICAL IMPACT

The management of type 2 endoleaks in post-EVAR patients has been a topic of debate. This retrospective single-center study, featuring strict inclusion criteria, included 109 patients with persistent type 2 endoleaks. The findings indicate that patients with lower D-dimer levels at 1- and 2-year follow-ups are unlikely to experience sac enlargement ≥5 mm within 5 years, even in the presence of type 2 endoleaks. This study suggests that D-dimer monitoring has the potential to reduce reliance on imaging studies for the follow-up of patients with type 2 endoleaks, leading to significant savings in medical resources.

Machine Learning Based Prediction of Post-operative Infrarenal Endograft Apposition for Abdominal Aortic Aneurysms

OBJECTIVE

Challenging infrarenal aortic neck characteristics have been associated with an increased risk of type Ia endoleak after endovascular aneurysm repair (EVAR). Short apposition (< 10 mm circumferential shortest apposition length [SAL]) on the first post-operative computed tomography angiography (CTA) has been associated with type Ia endoleak. Therefore, this study aimed to develop a model to predict post-operative SAL in patients with an abdominal aortic aneurysm based on the pre-operative shape.

METHODS

A statistical shape model was developed to obtain principal component scores. The dataset comprised patients treated by standard EVAR without complications (n = 93) enriched with patients with a late type Ia endoleak (n = 54). The infrarenal SAL was obtained from the first post-operative CTA and subsequently binarised (< 10 mm and ≥ 10 mm). The principal component scores that were statistically different between the SAL groups were used as input for five classification models, and evaluated by means of leave one out cross validation. Area under the receiver operating characteristic curves (AUC), accuracy, sensitivity, and specificity were determined for each classification model.

RESULTS

Of the 147 patients, 24 patients had an infrarenal SAL < 10 mm and 123 patients had a SAL ≥ 10 mm. The gradient boosting model resulted in the highest AUC of 0.77. Using this model, 114 patients (77.6%) were correctly classified; sensitivity (< 10 mm apposition was correctly predicted) and specificity (≥ 10 mm apposition was correctly predicted) were 0.70 and 0.79 based on a threshold of 0.21, respectively.

CONCLUSION

A model was developed to predict which patients undergoing EVAR will achieve sufficient graft apposition (≥ 10 mm) in the infrarenal aortic neck based on a statistical shape model of pre-operative CTA data. This model can help vascular specialists during the planning phase to accurately identify patients who are unlikely to achieve sufficient apposition after standard EVAR.

The sac evolution imaging follow-up after endovascular aortic repair: An international expert opinion-based Delphi consensus study

OBJECTIVE

Management of follow-up protocols after endovascular aortic repair (EVAR) varies significantly between centers and is not standardized according to sac regression. By designing an international expert-based Delphi consensus, the study aimed to create recommendations on follow-up after EVAR according to sac evolution.

METHODS

Eight facilitators created appropriate statements regarding the study topic that were voted, using a 4-point Likert scale, by a selected panel of international experts using a three-round modified Delphi consensus process. Based on the experts' responses, only those statements reaching a grade A (full agreement ≥75%) or B (overall agreement ≥80% and full disagreement <5%) were included in the final document.

RESULTS

One-hundred and seventy-four participants were included in the final analysis, and each voted the initial 29 statements related to the definition of sac regression (Q1-Q9), EVAR follow-up (Q10-Q14), and the assessment and role of sac regression during follow-up (Q15-Q29). At the end of the process, 2 statements (6.9%) were rejected, 9 statements (31%) received a grade B consensus strength, and 18 (62.1%) reached a grade A consensus strength. Of 27 final statements, 15 (55.6%) were classified as grade I, whereas 12 (44.4%) were classified as grade II. Experts agreed that sac regression should be considered an important indicator of EVAR success and always be assessed during follow-up after EVAR.

CONCLUSIONS

Based on the elevated strength and high consistency of this international expert-based Delphi consensus, most of the statements might guide the current clinical management of follow-up after EVAR according to the sac regression. Future studies are needed to clarify debated issues.

Understanding Type II Endoleak: A Harmless Imaging Finding or a Silent Threat?

Type II endoleak (T2EL) represents a challenging clinical entity following endovascular abdominal aortic aneurysm repair (EVAR). Although several studies have suggested that T2ELs are related to an increased risk of aneurysm sac growth and subsequent rupture, the exact role that T2ELs play in long-term outcomes remains debatable. Understanding the pathophysiology, diagnostic modalities, and management options of T2ELs is important for patients' safety and proper resource utilization. While conservative management may be suitable for asymptomatic patients with a stable aneurysm size, interventional approaches, including transarterial embolization, direct sac puncture embolization and open conversion have been described for patients with persistent T2EL associated with sac expansion. However, more research is needed to better determine the clinical benefit of such interventions. A thorough evaluation of all endoleak types before T2EL treatment would be reasonable for patients with T2ELs associated with sac expansion. Further studies are needed to refine treatment strategies aimed at minimizing T2EL-related complications. Collaborative efforts among vascular specialists, radiologists, and researchers are of paramount importance to address this ongoing clinical challenge.

Endovascular Treatment of Abdominal Aortic Aneurysm: Impact of Diabetes on Endoleaks and Reintervention

Background: Diabetes has a protective effect on abdominal aortic aneurysms (AAAs); however, there are contrasting reports on the impact of diabetes on endovascular aortic repair (EVAR) outcomes, endoleaks (ELs) being the major negative outcome. The present study characterizes ELs and their outcomes in AAA patients, diabetic or not. Methods: This single-center, retrospective, comparative study was carried out on 324 AAA patients who underwent elective EVARs between 2007 and 2016 at the University Hospital of Liège (Belgium). The primary endpoint was the incidence and effect of ELs on the evolution of the aneurysmal sac; the secondary endpoints were surgical reintervention and mortality rate. Diabetic and non-diabetic patients were compared with respect to various risk factors by logistic regression, while a Cox regression was used to analyze survival. Results: In AAA patients meeting the inclusion criteria (n = 248), 23% were diabetic. EL incidence was comparable (p = 0.74) in diabetic (38.7%) vs. non-diabetic (43.9%) patients. EL risk factors were age (HR = 1.04, p = 0.014) and fibrate intake (HR = 3.12, p = 0.043). A significant association was observed between ELs and aneurysm sac enlargement (p < 0.001), regardless of group (p = 0.46). Aneurysm sac regression per month for non-diabetic patients was -0.24 ± 0.013, while for diabetics it was -0.18 ± 0.027 (p = 0.059). Dyslipidemia (HR = 3.01, p = 0.0060) and sulfonylureas (HR = 8.43, p = 0.043) were associated with shorter EL duration, while diabetes (HR = 0.080, p = 0.038) and beta blockers (HR = 0.46, p = 0.036) were associated with longer EL duration. The likelihood of reoperation decreased with more recent surgery (OR = 0.90, p = 0.040), regardless of diabetic status. All-cause mortality was higher for the non-diabetic group (45.5% vs. 26.3%, p = 0.0096). Conclusions: Endoleak occurrence is a known risk factor for sac expansion. In diabetic patients, endoleaks lasted longer, and regression of the aneurysm sac tended to be slower. The number and type of reintervention was not related to the diabetic status of AAA patients, but overall survival was higher in patients with diabetes.

Estimation of the Added Cancer Risk Derived From EVAR and CTA Follow-Up

OBJECTIVE

The aim of this study was to assess the risk of radiation-induced cancer development in patients that have undergone an infrarenal EVAR, stratifying the relative contributions of the procedure and the preoperative and postoperative CTAs.

METHODS AND MATERIALS

The organ-specific absorbed radiation doses from CTA and the EVAR procedure were estimated from the radiation exposures of 95 and 45 male patients, respectively. Lifetime attributable risk (LAR) cancer predictions were calculated for 14 different organs. Life expectancy was assumed from a previous cohort of patients undergoing infra-renal EVAR.

RESULTS

The calculated total excess cancer risk was 0.0046, ie, 1 out of 220 patients will develop a neoplasm after being exposed to the ionizing radiation from the preoperative CTA, the EVAR and annual CTA examinations for 15 years. The procedure and the preoperative CTA contributed with 38% of the total excess risk, while the rest was derived from the follow-up. If the entire CTA based follow-up would have been eliminated, an excess risk of 0.0018 (1/560) would remain.

CONCLUSIONS

1 out of 219 patients who have undergone EVAR of an infra-renal AAA have a lifetime risk of developing cancer secondary to the radiation exposures related to the procedure and the CTAs used preoperatively and during follow-up. This risk derives mostly from the yearly postoperative CTAs, underlining the potential benefits of reducing or replacing their use.

CLINICAL IMPACT

A simulation-based estimation reinforced the potential deleterious effects of the radiation exposure for patients undergoing Endovascular Aneurysm Repair (EVAR) of Abdominal Aortic Aneurysms (AAA) and subsequently followed by yearly Computer Tomography Angiographies (CTAs). The risk could be as high as 1 out 219 patients developing a neoplasm after 15 years. The largest exposure derives from the follow-up CTAs and efforts to minimize their use as well as the intraoperative radiation are greatly needed. The simulation-based estimations done in this study reinforce potential deleterious effects of the radiation exposure for patients undergoing EVAR of AAA. Efforts should be done to minimize the intraoperative radiation and the number of CTAs used during follow-up.

A rare case of aortic endograft infection by Francisella tularensis: A case report

INTRODUCTION AND IMPORTANCE: endovascular repair is an alternative to open repair for abdominal aortic aneurysms (AAA), which lowers morbidity and mortality but may presents infectious complications. Endograft infection is a rare but serious life-threatening condition with a mortality rate up to 50 %. We reported a case of aortic endograft infection by Francisella tularensis, rare and highly virulent gram-negative coccobacillus known for use in bioterrorism. CASE PRESENTATION: A 79-year-old man presented with asthenia, weight loss, night sweats and one episode of fever. In 2007, he underwent aorto-bi-iliac endograft repair for AAA without any complication. The diagnostic workup showed some signs of inflammation, but negative blood cultures and no sign of infection on CT scan. The combination of positron emission tomography (PET) and white blood cell (WBC) scintigraphy led to the diagnosis of aortic endograft infection. The management was antimicrobial therapy and surgery. Perioperative analysis shows the presence of Francisella Tularensis. DISCUSSION AND CONCLUSIONS: Aortic endograft infection is a serious complication with a high mortality rate. Its diagnosis may be difficult, but the combination of WBC scintigraphy and PET scan may improve identification of the infection, even if blood cultures and CT scan are negative. The gold standard treatment is removal of the endograft, debridement, and in situ reconstruction along with antibacterial therapy.

Infrarenal Abdominal Aortic Aneurysm

Abdominal aortic aneurysms are found in up to 6% of men and 1.7% of women over the age of 65 years and are usually asymptomatic. The natural history of aortic aneurysms is continued dilation leading to rupture, which is associated with an overall 80% mortality. Of the patients with ruptured aneurysms that undergo intervention, half will not survive their hospitalization. Reduction in aneurysm mortality is therefore achieved by prophylactic repair during the asymptomatic period. On a population-based level, this is supported by abdominal aortic aneurysm screening programs. Approximately 60% of abdominal aortic aneurysms are confined to the infrarenal portion of the aorta and are amenable to repair with off-the-shelf endovascular devices. Endovascular techniques have now replaced open surgery as the primary modality for aneurysm repair.

Diminishing Endograft Apposition during Follow-Up Is an Important Indicator of Late Type 1a Endoleak after Endovascular Aneurysm Repair

Late type 1a endoleaks (T1aELs) after endovascular aneurysm repair (EVAR) are hazardous complications which should be avoided. This study investigated the evolution of the shortest apposition length (SAL) post-EVAR and hypothesised that a declining apposition during follow-up may be an indicator of T1aEL development. Patients with a late T1aEL were selected from a consecutive multicentre database. For each T1aEL patient, the preoperative computed tomography angiography (CTA), first postoperative CTA, and pre-endoleak CTA were analysed. T1aEL patients were matched 1:1 to uncomplicated controls, based on endograft type and follow-up duration. Anatomical characteristics and endograft dimensions, including the post-EVAR SAL, were measured. Included were 28 patients with a late T1aEL and 28 matched controls. The SAL decreased from 11.2 mm (5.6-20.6 mm) to 3.9 mm (0.0-11.4 mm) in the T1aEL group (p = 0.006), whereas an increase in SAL was seen in the control group from 21.3 mm (14.1-25.8 mm) to 25.4 mm (19.0-36.2 mm; p = 0.015). On the pre-endoleak CTA, 18 patients (64%) in the T1aEL group had a SAL < 10 mm, and one (4%) patient in the control group had a SAL < 10 mm on the matched CTAs. Moreover, three mechanisms of decreasing sealing zone were identified, which might be used to determine optimal imaging or reintervention strategies. Diminishing SAL < 10 mm is an indicator for T1aEL during follow-up, it is imperative to include apposition analysis during follow-up.

Editor's Choice - Meta-Analysis of Compliance with Endovascular Aneurysm Repair Surveillance: The EVAR Surveillance Paradox

OBJECTIVE

To compare the survival of patients who attended surveillance after endovascular aneurysm repair (EVAR) with those who were non-compliant.

DATA SOURCES

MEDLINE and Embase were searched using the Ovid interface.

REVIEW METHODS

A systematic review was conducted complying with the PRISMA guidelines. Eligible studies compared survival in EVAR surveillance compliant patients with non-compliant patients. Non-compliance was defined as failure to attend at least one post-EVAR follow up. The risk of bias was assessed with the Newcastle-Ottawa scale, and the certainty of evidence using the GRADE framework. Primary outcomes were survival and aneurysm related death. Effect measures were the hazard ratio (HR) or odds ratio (OR) and 95% confidence interval (CI) calculated using the inverse variance or Mantel-Haenszel statistical method and random effects models.

RESULTS

Thirteen cohort studies with a total of 22 762 patients were included. Eight studies were deemed high risk of bias. The pooled proportion of patients who were non-compliant with EVAR surveillance was 43% (95% CI 36 - 51). No statistically significant difference was found in the hazard of all cause mortality (HR 1.04, 95% CI 0.61 - 1.77), aneurysm related mortality (HR 1.80, 95% CI 0.85-3.80), or secondary intervention (HR 0.66, 95% CI 0.31 - 1.41) between patients who had incomplete and complete follow up after EVAR. The odds of aneurysm rupture were lower in non-compliant patients (OR 0.63, 95% CI 0.39 - 1.01). The certainty of evidence was very low for all outcomes. Subgroup analysis for patients who had no surveillance vs. those with complete surveillance showed no significant difference in all cause mortality (HR 1.10, 95% CI 0.43 - 2.80).

CONCLUSION

Patients who were non-compliant with EVAR surveillance had similar survival to those who were compliant. These findings question the value of intense surveillance in all patients post-EVAR and highlight the need for further research on individualised or risk adjusted surveillance.

Cost of Follow Up After Endovascular Abdominal Aortic Aneurysm Repair in Patients With an Initial Post-Operative Computed Tomography Angiogram Without Abnormalities

OBJECTIVE

The Observing a Decade of Yearly Standardised Surveillance in EVAR patients with Ultrasound or CT Scan (ODYSSEUS) study was conducted to assess differences in outcomes of patients with continued or discontinued yearly follow up after endovascular abdominal aortic aneurysm repair (EVAR). Earlier results of this study showed that discontinued follow up was not associated with poor outcomes. Therefore, an incremental cost analysis and budget impact analysis of de-implementation of yearly imaging following EVAR was performed.

METHODS

In total, 1 596 patients from the ODYSSEUS study were included. The expected cost savings were assessed if yearly imaging was reduced in patients with a post-operative computed tomography angiogram without abnormalities made around 30 days after EVAR. Costs were derived from the Dutch costs manual, benchmark cost prices, and literature review. Costs were expressed in euros (€) and displayed at 2019 prices. Sensitivity analysis was performed by varying costs.

RESULTS

A difference of 24% in cost was found between patients with continued and discontinued imaging follow up. The cost per patient was €1 935 in the continued group vs. €1 603 per patient in the discontinued group at five years post-EVAR, with a mean difference of €332 (95% bias corrected and accelerated bootstrap confidence interval -741 to 114). De-implementation of yearly imaging would result in an annual nationwide cost saving of €678 471. Sensitivity analysis with variation in adherence rates, imaging, or secondary intervention costs resulted in a saving of at least €271 388 per year.

CONCLUSION

This study provided an in depth analysis of hospital costs for post-EVAR patients in the Netherlands with a modest impact on the Dutch healthcare budget.