Midterm results of endovascular abdominal aortic aneurysm repair: comparison of instruction-for-use (IFU) cases and non-IFU cases

Pre-constrain technique using the Gore Excluder Conformable endograft for abdominal aortic aneurysm with severely angulated proximal neck

Endovascular aneurysm repair for abdominal aortic aneurysms with a severely angulated proximal neck remains challenging because of the higher rates of type 1a endoleaks and secondary interventions. In this study, we reviewed six consecutive patients with a severely angulated proximal neck (>60°) treated with endovascular aneurysm repair at a single center. They were treated with a Gore Excluder Conformable endograft using a pre-constrain technique to prevent type 1a endoleaks. It is the unique deployment technique of the proximal trunk by pre-constrain of the proximal edge. This technique helps obtain optimal deployment of the proximal main body.

Embolization for Type Ia Endoleak after EVAR for Abdominal Aortic Aneurysms: A Systematic Review of the Literature

(1) Successful endovascular repair for abdominal aortic aneurysms is based on the complete exclusion of the aneurysm sac from the systemic circulation. Type Ia endoleak (ELIA) is defined as the persistent perfusion of the aneurysm sac due to incomplete proximal sealing between aorta and endograft, with a consequent risk of rupture and death. Endoleak embolization has been sporadically reported as a viable treatment for ELIA. (2) A systematic literature search in PubMed of all publications in English about ELIA embolization was performed until February 2022. Research methods and reporting were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Data regarding patient numbers, technical success (endoleak absence at control angiography), reinterventions, clinical and imaging follow-up, and outcomes were collected and examined by two independent authors. (3) Twenty-one papers (12 original articles, 9 case reports) reported on 126 patients (age range 58-96 years) undergoing ELIA embolization 0-139 months after the index procedure. Indication for embolization was most often founded on unfavorable anatomy and patient comorbidities. Embolic agents used include liquid embolic agents, coils, plugs and combinations thereof. Technical success in this highly selected cohort ranged from 67-100%; the postprocedural complication rate within 30 days was 0-24%. ELIA recurrence was reported as 0-42.8%, with a secondary ELIA-embolization-intervention success rate of 50-100%. At a follow-up at 0-68 months, freedom from sac enlargement amounted to 76-100%, freedom from ELIA to 66.7-100%. (4) Specific literature about ELIA embolization is scant. ELIA embolization is a valuable bailout strategy for no-option patients; the immediate technical success rate is high and midterm and long-term outcomes are acceptable.

Aortic Neck IFU Violations During EVAR for Ruptured Infrarenal Aortic Aneurysms are Associated with Increased In-Hospital Mortality

OBJECTIVE

Vascular surgeons treating patients with ruptured abdominal aortic aneurysm must make rapid treatment decisions and sometimes lack immediate access to endovascular devices meeting the anatomic specifications of the patient at hand. We hypothesized that endovascular treatment of ruptured abdominal aortic aneurysm (rEVAR) outside manufacturer instructions-for-use (IFU) guidelines would have similar in-hospital mortality compared to patients treated on-IFU or with an infrarenal clamp during open repair (ruptured open aortic aneurysm repair [rOAR]).

METHODS

Vascular Quality Initiative datasets for endovascular and open aortic repair were queried for patients presenting with ruptured infrarenal AAA between 2013-2018. Graft-specific IFU criteria were correlated with case-specific proximal neck dimension data to classify rEVAR cases as on- or off-IFU. Univariate comparisons between the on- and off-IFU groups were performed for demographic, operative and in-hospital outcome variables. To investigate mortality differences between rEVAR and rOAR approaches, coarsened exact matching was used to match patients receiving off-IFU rEVAR with those receiving complex rEVAR (requiring at least one visceral stent or scallop) or rOAR with infrarenal, suprarenal or supraceliac clamps. A multivariable logistic regression was used to identify factors independently associated with in-hospital mortality.

RESULTS

621 patients were treated with rEVAR, with 65% classified as on-IFU and 35% off-IFU. The off-IFU group was more frequently female (25% vs. 18%, P = 0.05) and had larger aneurysms (76 vs. 72 mm, P= 0.01) but otherwise was not statistically different from the on-IFU cohort. In-hospital mortality was significantly higher in patients treated off-IFU vs. on-IFU (22% vs. 14%, P= 0.02). Off-IFU rEVAR was associated with longer operative times (135 min vs. 120 min, P= 0.004) and increased intraoperative blood product utilization (2 units vs. 1 unit, P= 0.002). When off-IFU patients were matched to complex rEVAR and rOAR patients, no baseline differences were found between the groups. Overall in-hospital complications associated with off-IFU were reduced compared to more complex strategies (43% vs. 60-81%, P< 0.001) and in-hospital mortality was significantly lower for off-IFU rEVAR patients compared to the supraceliac clamp group (18% vs. 38%, P= 0.006). However, there was no significantly increased mortality associated with complex rEVAR, infrarenal rOAR or suprarenal rOAR compared to off-IFU rEVAR (all P> 0.05). This finding persisted in a multivariate logistic regression.

CONCLUSIONS

Off-IFU rEVAR yields inferior in-hospital survival compared to on-IFU rEVAR but remains associated with reduced in-hospital complications when compared with more complex repair strategies. When compared with matched patients undergoing rOAR with an infrarenal or suprarenal clamp, survival was no different from off-IFU rEVAR. Taken together with the growing available evidence suggesting reduced long-term durability of off-IFU EVAR, these data suggest that a patient's comorbidity burden should be key in making the decision to pursue off-IFU rEVAR over a more complex repair when proximal neck violations are anticipated preoperatively.

Endovascular aortic repair in patients with challenging anatomies: the EXTREME study

AIMS

The aim of this study was to report the 30-day technical and clinical success with endovascular repair using the ultra-low-profile Ovation stent graft in patients judged to be outside the instructions for use (IFU) for conventional endografts, while amenable to treatment within the IFU for Ovation.

METHODS AND RESULTS

One hundred and twenty-two patients (78.65±7.67 years; 111 male) were enrolled. Patients were evaluated as being outside the IFU for standard endografts because of the absence of a suitable proximal aortic neck in 109 cases (89.3%), of inadequate access vessels in 13 (10.7%), or both in 111 (90.9%). Mean aneurysm (abdominal aortic aneurysm [AAA]) diameter was 52.96±10.1 mm; mean aortic neck length was 7.75±6.05 mm. Technical success (98.4%) was achieved in all but two patients due to a type Ia endoleak. At completion angiography, 15 (12.3%) patients presented a type II endoleak. All patients underwent 30-day follow-up. Primary clinical success at one month was 96.8%, assisted clinical success 98.4%. There were no type I endoleaks, while 12 (9.8%) type II endoleaks were still evident, in the absence of sac expansions. Two patients (1.6%) presented an asymptomatic limb occlusion.

CONCLUSIONS

Our experience suggests that, in a selected population of patients with challenging anatomy outside the IFU for conventional endografts, endovascular aneurysm repair (EVAR) using the Ovation stent graft can be performed safely with satisfactory immediate outcomes.

Editor's Choice - Comprehensive Literature Review of Radiation Levels During Endovascular Aortic Repair in Cathlabs and Operating Theatres

OBJECTIVE

Occupational exposure is a growing concern among the endovascular specialist community. Several types of imaging equipment are available, such as mobile C arms or hybrid rooms, and some have been shown to deliver higher levels of radiation. A literature review was conducted to identify studies reporting dose data during standard (EVAR) and complex abdominal aortic endovascular repair (fenestrated/branched EVAR [F/BEVAR]).

METHODS

A search of the MEDLINE and the Cochrane databases was performed by two independent investigators using the medical subject heading terms "aortic aneurysms", "radiation", and "humans" over a search period of 10 years. Studies with full text available in English and reporting radiation data independently from the imaging equipment type were included. Experimental studies were excluded.

RESULTS

The lowest dose-area product levels during EVAR and F/BEVAR were identified in hybrid rooms, while the highest were with fixed systems. When adherence to the as low as reasonably achievable principles was stipulated by the authors, dose reports tended to be among the lowest. Several studies, especially of F/BEVAR, report concerning levels of radiation for both patients and staff.

CONCLUSION

Modern imaging equipment type, team involvement with radiation management, and the support of recent imaging technologies such as fusion help to reduce the dose delivered during standard and complex EVAR. Investment in modern imaging technology should be considered in every centre providing endovascular management of aortic aneurysms.

National Numbers of Secondary Aortic Reinterventions after Primary Abdominal Aortic Aneurysm Surgery from the Dutch Surgical Aneurysm Audit

BACKGROUND

Long-term secondary aortic reinterventions (SARs) can be a sign of (lack of) effectiveness of abdominal aortic aneurysm (AAA) surgery. This study provides insight into the national number of SARs after primary AAA repair by endovascular aneurysm repair (EVAR) or by open surgical repair in the Netherlands.

METHODS

Observational study included all patients undergoing SAR between 2016 and 2017, registered in the compulsory Dutch Surgical Aneurysm Audit (DSAA). The DSAA started in 2013, SARs are registered from 2016. Characteristics of SAR and postoperative outcomes (mortality/complications) were analyzed, stratified by urgency of SAR. Data of SARs were merged with data of their preceded primary AAA repair, registered in the DSAA after January 2013. In these patients undergoing SAR, treatment characteristics of the preceded primary AAA repair were additionally described, with focus on differences between stent grafts.

RESULTS

Between 2016 and 2017, 691 patients underwent SAR, this concerned 9.3% of all AAA procedures (infrarenal/juxtarenal/suprarenal) in the Netherlands (77% elective/11% acute symptomatic/12% ruptured). Endoleak (60%) was the most frequent indication for SAR. SARs were performed with EVAR in 66%. Postoperative mortalities after SAR were 3.4%, 11%, and 29% in elective, acute symptomatic, and ruptured patients, respectively. In 26% (n = 181) of the patients undergoing SAR their primary AAA repair was performed after January 2013 and data of primary and SAR procedures could be merged. In 93% (n = 136), primary AAA repair was EVAR. Endografts primarily used were nitinol/polyester (62%), nitinol/polytetrafluoroethylene (8%), endovascular sealing (21%), and others (9%), compared with their national market share of 76% (odds ratio [OR], 0.52; 95% confidence interval [CI], 0.38-0.71), 15% (OR, 0.50; CI, 0.29-0.89), 4.9% (OR, 5.04; CI, 3.44-7.38), and 4.1% (OR, 2.81; CI, 1.66-4.74), respectively.

CONCLUSIONS

In the Netherlands, about one-tenth of the annual AAA procedures concerns an SAR. A quarter of this cohort had an SAR within 1-5 years after their primary AAA repair. Most SARs followed after primary EVAR procedures, in which an overrepresentation of endovascular sealing grafts was seen. Postoperative mortality after SAR is comparable with primary AAA repair.

Type II endoleak model creation and intraoperative aneurysmal sac embolization with n-butyl cyanoacrylate-lipiodol-ethanol mixture (NLE) in swine

Background

The purpose of this study was to evaluate the feasibility of type II endoleak model creation and efficacy of intraoperative aneurysmal sac embolization using n-butyl-2-cyanoacrylate-lipiodol-ethanol mixture (NLE) for type II endoleak in swine.

Methods

In six swine (mean body weight 53.5 kg), abdominal aortic aneurysm (AAA) was created and then end-to-side anastomosis between the left renal artery and AAA sac was performed. And then, endovascular abdominal aortic aneurysm repair (EVAR) was performed, leading to creation of a type II endoleak model. As control group, EVAR without sac embolization was performed in two swine. In four swine, AAA sac was embolized using NLE immediately after EVAR via the microcatheter placed in AAA sac (NLE embolization group). Follow-up aortography was performed immediately and three days after the procedure, and then the aneurysms were extracted.

Results

The AAA sac and type II endoleak model were successfully created in all cases. In control group, type II endoleak persisted three days after the procedure. In NLE embolization group, endoleak disappeared immediately and three days after the procedure. In NLE embolization group, AAA sac was occupied with thrombus and embolic material. Inflammatory changes were recognized in aneurysmal sac wall in NLE embolization group.

Conclusions

This experimental study suggests that creation of a type II endoleak model in swine is feasible and that intraoperative AAA sac embolization with NLE during EVAR might reduce the occurrence of type II endoleak.

Sex-dependent outcomes following elective endovascular aortic repair

BACKGROUND

Evidence has shown that women derive less benefit from endovascular aortic repair (EVAR) in large part due to more challenging aortoiliac anatomy. This study sought to examine whether sex-dependent outcomes exist following elective EVAR cases.

METHODS

An institutional retrospective review was performed on patients who underwent elective EVAR procedures between 2008 and 2014. Outcome data collected included procedural and hospital morbidity, mortality, and overall EVAR durability based on the incidence of unplanned graft-related secondary interventions (SIs) (e.g., open conversion, proximal or distal extensions, and coil embolizations).

RESULTS

One hundred eighty-one patients (150 men, 31 women) met the study inclusion criteria. Median follow-up was 40.3 mo. Women had more challenging anatomy compared to men including smaller overall iliac diameters (6.8 mm versus 8.0 mm, P < 0.001) and more severe iliac angulation (77% moderate to severe versus 44%, P < 0.001). Women had increased risk of postoperative complications compared to men (41.9% versus 11.3%, P = 0.003). There was no perioperative mortality in our series of elective EVAR cases. Median 5-y survival following EVAR was 64.4% for men and 76.3% for women (P = 0.599). Late SI rates following EVAR was 10.5% with 16 (10.7%) men and 3 (9.7%) women needing interventions (P = 0.870). Overall durability of EVAR extrapolated as time to SIs was 91% at 2 y and 85% at 5 y. Factors predisposing SIs were iliac tortuosity (P = 0.046), aortic neck angle (P = 0.022), and endoleak at the follow-up (P = 0.030).

CONCLUSIONS

In this study, immediate outcomes following EVAR were different between men and women, with women having increased rates of postoperative complications. Mortality and overall long-term durability of EVAR, however, were the same between sexes despite anatomical differences. EVAR durability was significantly dependent on the severity of iliac tortuosity, aortic neck angulation, and presence of endoleak at the follow-up.

Risk factors associated with late aneurysmal sac expansion after endovascular abdominal aortic aneurysm repair

PURPOSE

We aimed to identify the risk factors associated with late aneurysmal sac expansion after endovascular abdominal aortic aneurysm repair (EVAR).

METHODS

We retrospectively reviewed contrast-enhanced computed tomography (CT) images of 143 patients who were followed for ≥6 months after EVAR. Sac expansion was defined as an increase in sac diameter of 5 mm relative to the preoperative diameter. Univariate and multivariate analyses were performed to identify associated risk factors for late sac expansion after EVAR from the following variables: age, gender, device, endoleak, antiplatelet therapy, internal iliac artery embolization, and preprocedural variables (aneurysm diameter, proximal neck diameter, proximal neck length, suprarenal neck angulation, and infrarenal neck angulation).

RESULTS

Univariate analysis revealed female gender, endoleak, aneurysm diameter ≥60 mm, suprarenal neck angulation >45°, and infrarenal neck angulation >60° as factors associated with sac expansion. Multivariate analysis revealed endoleak, aneurysm diameter ≥60 mm, and infrarenal neck angulation >60° as independent predictors of sac expansion (P < 0.05, for all).

CONCLUSION

Our results suggest that patients with small abdominal aortic aneurysms (<60 mm) and infrarenal neck angulation ≤60° are more favorable candidates for EVAR. Intraprocedural treatments, such as prophylactic embolization of aortic branches or intrasac embolization, may reduce the risk of sac expansion in patients with larger abdominal aortic aneurysms or greater infrarenal neck angulation.

Systolic Sac Pressure Index for the Prediction of Persistent Type II Endoleak for 12 Months After Endovascular Abdominal Aortic Aneurysm Repair

PURPOSE

To assess the relationship between the systolic sac pressure index (SPI) and the presence of endoleaks 12 months after endovascular abdominal aortic aneurysm repair (EVAR).

MATERIALS AND METHODS

We performed a single-center prospective trial of consecutively treated patients. SPI (calculated as systolic sac pressure/systolic aortic pressure) was measured by catheterization immediately after EVAR. Contrast-enhanced computed tomography was scheduled 12 months after EVAR to detect possible endoleaks.

RESULTS

Data were available for 34 patients who underwent EVAR for an AAA. Persisting type II endoleak was found in 8 patients (endoleak-positive group) but not in the other 26 patients (endoleak-negative group). The mean ± standard deviation SPI was significantly greater in the endoleak-positive group than in the endoleak-negative group (0.692 ± 0.048 vs. 0.505 ± 0.081, respectively; P = .001). Receiver-operating characteristic curve analysis revealed that an SPI of 0.638 was the optimum cutoff value for predicting a persistent endoleak at 12 months with high accuracy (0.971; 33/34), sensitivity (1.00), and specificity (0.962) values. The mean change in AAA diameter was -4.28 ± 5.03 mm and 2.22 ± 4.54 mm in patients with SPI of <0.638 or ≥0.638, respectively (P = .002).

CONCLUSION

Patients with an SPI of ≥0.638 immediately after EVAR were more likely to have a persistent type II endoleak at 12 months with an accuracy of 0.971, and showed increases in aneurysm sac diameter compared with patients with an SPI of <0.638.

8-Year Long-Term Outcome Comparison: Two Ways to Exclude the Internal Iliac Artery during Endovascular Aorta Repair (EVAR) Surgery

Purpose

To evaluate the 8-year long-term outcome after internal iliac artery (IIA) coverage with or without embolization in EVAR.

Patients and Methods

From January 2006 to December 2013, abdominal aortic aneurysm (AAA) subjects that underwent EVAR and IIA exclusion were recruited and analyzed retrospectively. All the subjects were divided into group A or B based on the presence or absence of intraoperative IIA embolization before coverage (group A: without embolization; group B: with embolization). The 30-day mortality, stent patency, and the incidences of endoleaks and ischemia of the buttocks and lower limbs were compared. The follow-up period was 96 months.

Result

There were 137 subjects (A: 74 vs. B: 63), 124 male (91.1%) and 13 female (9.5%), with a mean age of 71.6 years. There were no significant differences in the early outcomes of intraoperative blood loss (87.23±14.07 ml; A: 86.53±9.57 ml vs. B: 88.06±18.04 ml, p = .545) and surgery time (87.13±9.25 min; A: 85.99±7.07 min vs. B: 88.48±11.19 min, p = .130). However, there were significant differences in contrast consumption (65.18±9.85 ml; A: 61.89±7.95 ml vs. B: 69.05±10.50 ml, p<.001) and intraoperative X-ray time (5.9±0.86 min; A: 5.63±0.49 min vs. B: 6.22±1.07 min, P<.001). The 30-day mortality was approximately 0.73%. In the follow-up analysis, no significant differences were identified in the incidence of endoleak (22 subjects; type I: A: 2 vs. B: 2, p = 1.000; type II: A: 8 vs. B: 4, p = .666; type III: A: 4 vs. B: 3, p = 1.000), occlusion (5 subjects; 4.35%; A: 1 vs. B: 4, p = .180), or ischemia (9 subjects; 7.83%; A: 3 vs. B: 6, p = .301). In the analysis of group B, although there were no significant differences between subjects with unilateral and bilateral IIA embolization, but longer hospital stays were required (P<.001), and a more severe complication (skin and gluteus necrosis) occurred in 1 subject with bilateral IIA embolization.

Conclusion

IIA could be excluded during EVAR. IIA coverage without embolization had a good surgical and prognostic outcome, and this procedure was not different significantly from coverage with embolization in terms of endoleaks, patency and ischemia.

Systematic review and meta-analysis of migration after endovascular abdominal aortic aneurysm repair

Aim

To identify patients who are under higher threat for migration because of an old generation stent graft application.

Methods

A systematic review and meta-analysis of the literature was undertaken to identify all studies which included older generation endografts and data reporting on graft migration after EVAR. Outcome data were pooled and combined, and were calculated using fixed or random effects models.

Results

From 2000 to 2014, 22 retrospective studies were identified reporting on stent- graft migration after EVAR (8.6%). From those patients, 39% received re-intervention with the mean time of identification ranging from 12 to 36 months. Six of these retrospective nonrandomized studies were eligible for meta-analysis. AAA diameter (AAA diameter: 0.719 mm; 95% confidence interval [CI]: 0.00065–1.4384 mm; p = 0.00497) and neck length (neck length: 4.36 mm; 95% CI: 1.3277–7.394; p = 0.0048) were the only significant factors associated with stent- graft migration. Neck diameter and neck angulation did not have any important influence on stent-graft migration.

Conclusions

Patients with large AAA and short necks who were treated with older generation stent grafts such as AneurX and Talent are in higher risk for endograft migration than others. Stent- graft migration consists of an insidious and underestimated threat.

Elective endovascular aortic repair conversion for type Ia endoleak is not associated with increased morbidity or mortality compared with primary juxtarenal aneurysm repair

OBJECTIVE

Type Ia endoleak after endovascular aortic repair (EVAR) can be a challenging complication to manage, and due to concerns regarding morbidity and mortality of open surgical conversion (OSC), reports of complex endoluminal salvage techniques are increasing. Despite development of these endovascular remedial strategies, many patients ultimately require OSC. The purpose of this analysis was to outcomes of elective OSC for type Ia endoleak and compare them with elective primary open juxtarenal aneurysm repair (OJAR) to determine if these concerns are warranted.

METHODS

From 2000 to 2012, 54 patients underwent EVAR OSC at median time of 27 months (interquartile range, 9-55 months). Indications included endograft thrombosis in 2 (4%), intraoperative EVAR failure in 3 (6%), rupture in 5 (9%), graft infection in 6 (11%), and type Ia endoleak in 25 (all: 38 [70%]). Because many OSCs are performed for emergency indications without endovascular options, we chose elective type Ia endoleak patients as our study group. These 25 patients were compared with an elective OJAR cohort matched by anatomy and comorbidities. Primary end points were 30-day and 1-year mortality. Secondary end points included early complications, cross-clamp time, procedure time, blood loss, and length of stay.

RESULTS

Demographic and comorbidity data in the OSC and OJAR groups did not differ, with the exception that OJAR patients presented with smaller aneurysm diameter and a higher rate of chronic obstructive pulmonary disease (P = .03). OSC patients more frequently underwent a nontube graft repair (OSC, n = 20 [80%] vs OJAR, n = 6 [24%]; P = .0002), required longer procedure times (P = .03), and received more plasma transfusions (P = .03). The 30-day mortality was 4% in both groups (observed difference in rates, 0%; 95% confidence interval for difference in mortality rates, -14.0% to 14.0%; P = 1). A similar rate of major complications occurred (OSC, n = 9 [36%] vs OJAR, n = 8 [32%]; P = 1). One-year survival was 83% in OSC and 91% in OJAR (observed difference, 7%; 95% confidence interval, -15% to 29%; P = .65).

CONCLUSIONS

Despite many advances in EVAR technology, the need for OSC persists and will likely become more common as older-generation devices fail or providers attempt EVAR in more anatomically complex patients. Elective OSC for type Ia endoleak can be technically challenging but is not associated with increased morbidity or mortality compared with OJAR in appropriately selected patients. These results should be considered before pursuing complex endovascular remediation of EVAR failures.