Mortality and morbidity following endovascular repair of abdominal aortic aneurysms: analysis of two single centre experiences

Transrenal Endovascular Aneurysm Repair-A Novel Approach for Abdominal Aortic Aneurysms with Difficult Neck Anatomy

BACKGROUND

The endovascular approach to treating ruptured or symptomatic abdominal aortic aneurysms (AAAs) with difficult neck anatomy still poses a major challenge. This study proposes and evaluates the outcomes of a novel technique, Transrenal Endovascular Aneurysm Repair (Tr-EVAR) which utilizes the top ring 'valley' and 'peak' configuration of the Anaconda stent graft to achieve proximal seal in AAAs with an unfavourable neck.

METHODS

All patients treated with Tr-EVAR over a period of 10 years were identified retrospectively. Demographic, clinical and outcome data were collected, and survival analysis was performed. The time-to-event was analyzed using Kaplan-Meier curves for complication-free survival, reintervention-free survival, and overall survival.

RESULTS

During the study period, 36 patients ruptured, symptomatic or large AAAs having unfavorable necks and not fit for open repair underwent Tr-EVAR. Two patients died in the first 30 days postprocedure (5.6%). The overall survival at 1 year, 3 years and 5 years were 86%, 72% and 54% respectively with a mean overall survival of 74.0 months (SE 7.8, 95% confidence interval 58.7-89.3) which was comparable to chimney endovascular aneurysm repair (EVAR). The complication-free survival and reintervention-free survival at 1 year, 3 years, and 5 years were 75%, 61%, 42%, 78%, 64%, and 45%, respectively.

CONCLUSIONS

Tr-EVAR can be considered as an off-the-shelf solution for urgent cases not fit for open repair with unfavourable neck features for standard EVAR. Careful patient selection and planning have generated acceptable immediate, midterm and long-term results comparable to those presented by chimney EVAR in the literature.

Quantifying the burden of survivorship associated with infrarenal abdominal aortic aneurysms

OBJECTIVES

Survivorship encompasses the physical, psychological, social, functional, and economic experience of a living with a chronic condition for both the patient and their caregiver. It is made up of nine distinct domains and remains understudied in nononcological pathologies, including infrarenal abdominal aortic aneurysmal disease (AAA). This review aims to quantify the extent to which existing AAA literature addresses the burden of survivorship.

METHODS

The MEDLINE, EMBASE, and PsychINFO databases were searched from 1989 through September 2022. Randomized controlled trials, observational studies, and case series were included. Eligible studies had to detail outcomes related to survivorship in patients with AAA. Owing to the heterogeneity between studies and outcomes, no meta-analysis was conducted. Study quality was assessed with specific risk of bias tools.

RESULTS

A total of 158 studies were included. Of these, only five (treatment complications, physical functioning, comorbidities, caregivers, and mental health) of the nine domains of survivorship have been studied previously. The available evidence is of variable quality; most studies display a moderate to high risk of bias, are of an observational study design, are based within a limited number of countries, and consist of an insufficient follow-up period. The most frequent complication after EVAR was endoleak. EVAR is associated with poorer long-term outcomes compared with open surgical repair in most studies retrieved. EVAR showed better outcomes in regard to physical functioning in the short term, but this advantage was lost in the long term. The most common comorbidity studied was obesity. No significant differences were found between open surgical repair and EVAR in terms of impact on caregivers. Depression is associated with various comorbidities and increased the risk of a nonhospital discharge.

CONCLUSIONS

This review highlights the absence of robust evidence regarding survivorship in AAA. As a result, contemporary treatment guidelines rely on historic quality-of-life data that are narrow in scope and nonrepresentative of contemporary clinical practice. As such, there is an urgent need to reevaluate the aims and methodology associated with traditional quality-of-life research moving forward.

Statin Use Is Associated with Reduced All-Cause Mortality after Endovascular Abdominal Aortic Aneurysm Repair

It has been shown that preoperative statin therapy reduces all-cause and cardiovascular mortality in patients undergoing major noncardiac vascular surgery. In this report, we investigated the influence of statin use on early and late outcome following endovascular abdominal aortic aneurysm repair (EVAR).

The study population, consisting of patients collated in the EUROSTAR registry, was stratified in two groups according to statin use. Baseline characteristics between the two groups were compared by chi-square and Wilcoxon rank sum tests for discrete and continuous variables. The effects of statin use on outcomes after EVAR were analyzed by multivariate regression models.

Of the 5,892 patients enrolled in the EUROSTAR registry, 731 (12.4%) patients used statins for hyperlipidemia. Statin users were younger, were more obese, and had a higher prevalence of diabetes, cardiovascular disease, and hypertension. After 5 years of follow-up, the cumulative survival rate was 77% for nonusers of statin versus 81% for statin users ( p = .005). After adjustment for age and other risk factors, statin use was still an independent predictor of improved survival ( p = .03).

Our results revealed that statin prescription was more frequent in younger patients. However, when adjusted for age and medical risk factors, the use of statin in patients who underwent EVAR was still independently associated with reduced overall mortality.

Systematic Review and Meta-analysis of 12 Years of Endovascular Abdominal Aortic Aneurysm Repair

BACKGROUND

Endovascular repair (ER) of abdominal aortic aneurysm (AAA) is a new technique, and reported rates of endoleak, conversion to open repair, rupture and mortality vary widely. The aim of this study was to estimate these rates from the published data, and examine how this has changed as more patients have undergone ER.

METHODS

A systematic review and meta-analysis of publications identified through searches of the electronic databases EMBASE and Medline. All publications quoting endoleak, conversion to open repair, rupture and mortality rates for a series of patients undergoing ER were included.

RESULTS

163 studies pertaining to 28,862 patients undergoing ER were identified as relevant for the review and meta-analysis. The pooled estimate for operative mortality was 3.3% (95% confidence interval 2.9 to 3.6%). The pooled estimate for type 1 endoleaks was 10.5% (95% confidence interval 9.0 to 12.1%), with an annual rate of 8.4% (95% confidence interval 5.7% to 12.2%). The pooled estimate of type 2,3 and 4 endoleaks was 13.7% (95% confidence interval 12.3 to 15.3%), with an annual rate of 10.2% (95% confidence interval 7.4% to 14.1%). The pooled estimate for primary conversion to open repair was 3.8% (95% confidence interval 3.2 to 4.4%), and for secondary conversion to open repair 3.4% (95% confidence interval 2.8 to 4.2%). The pooled estimate for post-operative rupture was 1.3% (95% confidence interval 1.1 to 1.7%), with an annual rupture rate of 0.6% (95% confidence interval 0.5% to 0.8%). Multivariate meta-regression analysis showed that rates of operative mortality, post-operative rupture and total number of endoleaks all fell significantly (p<0.05) over time.

CONCLUSIONS

This study demonstrates a low mortality and a gradual reduction in vascular morbidity and mortality associated with endovascular repair since it was first introduced.

Influence of Infrarenal Neck Length on Outcome of Endovascular Abdominal Aortic Aneurysm Repair

PURPOSE

To evaluate the influence of the infrarenal neck length on clinical outcome after endovascular abdominal aortic aneurysm repair (EVAR).

METHODS

Data were analyzed from 3499 patients enrolled in the EUROSTAR registry between January 1999 and April 2005 who underwent EVAR with a Talent or Zenith endograft and had detailed morphological data recorded. The study cohort was divided into 3 groups according to infrarenal neck length: >15 mm (reference group A, n=2822), 11 to 15 mm (group B, n=485), and < or =10 mm (group C, n=192). Uni- and multivariate analyses were performed to evaluate differences in clinical outcomes among the study groups.

RESULTS

After correction for confounders, proximal type I endoleak within 30 days occurred in 10.9% of group C compared to 2.6% of group A (OR 4.46, 95% CI 2.61 to 7.61). Within 48 months of follow-up (median 12 months), the incidence of proximal endoleaks was higher in groups B (9.6%; HR 1.98, 95% CI 1.16 to 3.38) and C (11.3%; HR 2.132, 95% CI 1.17 to 4.60) compared to group A (3.4%).

CONCLUSION

Our study indicates that endovascular treatment of abdominal aortic aneurysms with infrarenal neck length <15 mm is associated with significantly increased risk of short- and midterm proximal endoleaks after EVAR. The greater risk of proximal endoleaks should be weighed against the risks of alternative treatment modalities.

Systematic review of recent evidence for the safety and efficacy of elective endovascular repair in the management of infrarenal abdominal aortic aneurysm

Background

Conventional management of abdominal aortic aneurysm (AAA) is by open repair and is associated with a mortality rate of 2–6 per cent. Endovascular aneurysm repair (EVAR) is an alternative technique first introduced in 1991. A systematic review was undertaken of the evidence for the safety and efficacy of elective EVAR in the management of asymptomatic infrarenal AAA.

Methods

Thirteen electronic bibliographical databases were searched, covering biomedical, health-related, science and social science literature. Outcomes were assessed with respect to efficacy (successful deployment, technical success, conversion rates and secondary intervention rates) and safety (30-day mortality rate, procedure morbidity rates and technical issues—endoleaks, graft thrombosis, stenosis and migration).

Results

Of 606 reports identified, 61 met the inclusion criteria (three randomized and 15 non-randomized controlled trials, and 43 uncontrolled studies). There were 29 059 participants in total; 19 804 underwent EVAR. Deployment was successful in 97·6 per cent of cases. Technical success (complete aneurysm exclusion) was 81·9 per cent at discharge and 88·8 per cent at 30 days. Secondary intervention to treat endoleak or maintain graft patency was required in 16·2 per cent of patients. Mean stay in the intensive care unit and mean hospital stay were significantly shorter following EVAR. The 30-day mortality rate for EVAR was 1·6 per cent (randomized controlled trials) and 2·0 per cent in nonrandomized trials and case series. Technical complications comprised stent migration (4·0 per cent), graft limb thrombosis (3·9 per cent), endoleak (type I, 6·8 per cent; type II, 10·3 per cent; type III, 4·2 per cent) and access artery injury (4·8 per cent).

Discussion

EVAR is technically effective and safe, with lower short-term morbidity and mortality rates than open surgery. However, there is a need for extended follow-up as the long-term success of EVAR in preventing aneurysm-related deaths is not yet known.

Suprarenal Endograft Fixation Avoids Adverse Outcomes Associated with Aortic Neck Angulation

The advent of endovascular therapy has had a profound impact on repair of abdominal aortic aneurysms (AAA). Prudent patient selection, particularly in regard to unfavorable anatomy, is emerging as perhaps the most important determinant of endovascular abdominal aortic aneurysm repair (EVAR) outcome. The aim of this study was to examine the association of one such anatomic factor, proximal aortic neck angulation, with the incidence of adverse events following EVAR. Prospectively collected data on 289 EVAR repairs with the Talent endograft (Medtronic, Inc., Minneapolis, MN) from March 1998 to June 2000 were analyzed. Stent graft-specific adverse events studied were migration, endoleak, kinking, thrombosis, and AAA expansion. Computed tomography (CT) scanning with three-dimensional post-processing and/or aortography was used to measure aortic neck angle. Patients were categorized into one of four groups according to their neck angle: I (0-10 degrees); II (11-39 degrees); III (40-59 degrees); or IV (60-85 degrees). Outcomes were evaluated by chi-squared analysis and ANOVA. There was a direct correlation between AAA diameter and neck angle (p = 0.002). There was no difference in endoleak rate (p = 0.877), stent migration (p = 0.850), or AAA expansion rate (p = 0.599) between groups. Device kinking >45 degrees was associated with neck angulation > or = 60 degrees (p = 0.013), but not with other adverse outcomes. The average neck angle was 30 degrees in patients with endoleaks and 31 degrees in patients without endoleaks. Increasing aortic neck angulation was not associated with the selected adverse outcomes within 1 year following EVAR with the Talent stent graft using suprarenal fixation with the exception of graft kinking. This may be related to the graft design that permits suprarenal aortic fixatiou of the proximal stent graft, Whether severe degrees of angulation of 60 degrees or greater can be safely treated with suprarenal fixation requires further study.

Does hostile neck anatomy preclude successful endovascular aortic aneurysm repair?

OBJECTIVES

Poor outcomes have been reported with endovascular aneurysm repair (EVAR) in patients with hostile neck anatomy. Unsupported endografts with active fixation may offer certain advantages in this situation. We compared EVAR results using the Ancure (Guidant) endograft in patients with and without hostile neck anatomy.

METHODS

Records of EVAR patients from October 1999 to July 2002 at a tertiary care hospital were retrospectively reviewed from a division database. Patients with elective open abdominal aortic aneurysm (AAA) repair during the same period were reviewed to determine those unsuitable for EVAR. Hostile neck anatomy, assessed by computer tomography (CT) scans and angiograms, was defined as one or more of the following: (1) neck length </=10 mm, (2) focal bulge in the neck >3 mm, (3) >2-mm reverse taper within 1 cm below the renal arteries, (4) neck thrombus > or =50% of circumference, and (5) angulation > or =60 degrees within 3 cm below renals.

RESULTS

Three hundred and twenty-two patients underwent EVAR with an average follow-up of 18 months. Patients in Phase II trials (n = 41), repaired with other graft types (n = 48), or without complete anatomic records (n = 27) were excluded. Demographics and co-morbidities were similar in the 115 good-neck (GN) and 91 bad-neck (BN) patients except for age (mean, 72.9 years GN vs 75.7 BN; P = 0.13), gender (11% female GN vs 22% BN; P =.04); neck length (mean, 21.8 mm GN vs 14.4 mm BN: P <.001), and angulation (mean, 22 degrees GN vs 40 degrees BN; (P <.001). Perioperative mortality (0 GN vs 1.1% BN), late mortality (5.2% GN vs 4.4% BN), all endoleaks (19.1% GN vs 17.6% BN), proximal endoleaks (0.8% GN vs 2.1% BN), and graft migration (0 for both groups) did not reach statistical significance. Neck anatomy precluded EVAR in 106 of 165 (64%) patients with open AAA.

CONCLUSIONS

Unsupported endografts with active fixation can yield excellent results in treating many medically compromised patients with hostile neck anatomy. Nonetheless, an unsuitable neck remains the most frequent cause for open abdominal AAA.

Eligibility rates of ruptured and symptomatic AAA for endovascular repair

PURPOSE

To determine the anatomical eligibility rate for endovascular repair of ruptured and symptomatic abdominal aortic aneurysms (AAA) using commercially available endografts.

METHODS

In a retrospective review, 28 preoperative computed tomographic (CT) scans were examined from among 83 patients who underwent surgical repair of a ruptured or acutely symptomatic AAA at a university-based tertiary care center during the past 10 years. The proximal aortic neck, aneurysm, and iliac dimensions were compared to corresponding measurements from 100 preoperative CT scans from patients who underwent elective repair of asymptomatic AAA. Based on expanded selection criteria for the 2 FDA-approved endografts (AneuRx and Ancure), eligibility rates for endovascular repair were compared between patients with ruptured/symptomatic and asymptomatic AAAs.

RESULTS

The proximal neck of the ruptured/symptomatic AAAs was on the average 2 mm larger in diameter (25 +/- 4 versus 23 +/- 3 mm, p=0.04) and 7 mm shorter (16 +/- 10 versus 23 +/- 14, p=0.017) than asymptomatic AAAs. The maximum AAA diameter was significantly larger in the ruptured/symptomatic group (64 +/- 16 mm) than in the asymptomatic group (58 +/- 11 mm, p=0.033). Of the 28 ruptured/symptomatic AAAs assessed morphologically, 13 (46%) were anatomically eligible for endovascular repair compared to 74 of the 100 asymptomatic AAAs (p=0.006). The main cause for exclusion was an unfavorable proximal neck, which was present in 15 (54%) of the 28 ruptured/symptomatic AAAs and in 24 (24%) of the 100 asymptomatic AAAs (p=0.003).

CONCLUSIONS

A significantly smaller proportion of patients presenting with ruptured/symptomatic AAA are anatomically eligible for endovascular AAA repair compared to patients with asymptomatic AAA due to unfavorable proximal neck anatomy.