Failed Endovascular Aneurysm Repair Research Articles

Salvage endovascular septectomy in patients with chronic abdominal aortic dissection after failed endovascular aneurysm repair.

This study aimed to investigate the efficacy and safety of salvage endovascular septectomy in patients with abdominal chronic aortic dissection (CAD) after endovascular aneurysm repair. A study cohort comprising 6 patients with chronic abdominal aortic dissection after failed endovascular aortic repair [mean age 62.5 (36-69) years] were enrolled to undergo salvage endovascular septectomy. The procedure involved entering the false lumen via the intrinsic visceral entry to perform a confined septectomy using a 'Gigli wire' to merge the true and false lumens. The outcomes were assessed by Digital angiography and computed tomography angiography. All 6 patients were successfully operated on; the diameters of the visceral abdominal aorta and the infrarenal abdominal aorta were similar at 1, 3, 6 and 12 months compared with the baseline; the patency of the visceral branch arteries was also stable at 1, 3, 6 and 12 months compared with the baseline; no occlusion of the visceral branch arteries was noted; no major vascular adverse events or deaths were observed. In this preliminary study, it was proven that salvage endovascular septectomy is a potentially advantageous technique that is safe and effective in the treatment of patients with CAD after failed endovascular aortic repair.

Explant of aortic stent grafts following endovascular aneurysm repair.

Background Failure of endovascular aneurysm repair may require explant of the stent graft in a subset of patients. We sought to assess outcomes in a cohort of patients undergoing explant of endovascular aneurysm repair in both emergency and elective settings. Methods Patients undergoing explant of endovascular aneurysm repair were identified from a prospectively maintained database, with additional information obtained through retrospective analysis of medical records. Results Over a 21-year period, 1997–2018 (May), there were 597 endovascular aneurysm repair procedures performed in our institution for abdominal aortic aneurysm. There were 19 endovascular aneurysm repair explants; five of these were referrals from other vascular centres. The median age was 73 years (range 46–81). The median length of time from insertion to explant was 39.2 months (range 0–153). Indications for elective explant were type Ia endoleak (n = 4), type 1b endoleak (n = 1), type II endoleak with increasing sac size (n = 1), type I/III endoleak (n = 1), type IV endoleak (n = 1), and increasing sac size without evident endoleak (type V, n = 2). The remaining nine cases were emergency procedures, with four patients presenting with rupture post endovascular aneurysm repair, four patients presenting with acute stent thrombosis, of which one also had a type 1a endoleak and one aorto-enteric fistula. There were no mortalities in the elective group and three mortalities in the emergency group (0 vs 33.3%, p = 0.087). Overall 30-day mortality was 15.8% Conclusion Explant of aortic stent grafts can be associated with high mortality and morbidity rates, especially in the emergent setting. Patient and device selection and post-operative surveillance remain vitally important to optimise outcomes post endovascular aneurysm repair.

Management of failed endovascular aortic aneurysm repair with explantation or fenestrated-branched endovascular aortic aneurysm repair

ObjectiveThe incidence of failed endovascular aneurysm repair (EVAR) is increasing, and understanding the different methods of management and repair is paramount. The objective of this study was to evaluate the clinical management and rescue of failed EVAR by either explantation or fenestrated-branched EVAR (F/B-EVAR). MethodsA retrospective analysis (1999-2016) of 247 patients who underwent either explantation (n = 162) or F/B-EVAR (n = 85) for failed EVAR was performed. F/B-EVAR was performed under a physician-sponsored investigational device exemption. Demographics of the patients, clinical presentation and failure etiology, perioperative management, rate of reinterventions, morbidity, and mortality were analyzed. Those undergoing surgical explantation were compared with those undergoing F/B-EVAR conversion. Statistical analysis included multivariable logistic regressions, Fisher exact test, and χ2 test. ResultsThe majority of patients were male (n = 216 [87%]), with a mean age of 75 years (range, 50-93 years). The mean time from primary EVAR was higher in F/B-EVAR (46 ± 7 months vs 69 ± 41 months; P < .001). Graft manufacturer did not differ between those requiring explantation and those having endovascular rescue (P = .170). All emergencies (n = 24 [10%]) and infections (n = 28 [11%]) were treated with open conversion. Endoleak was the most common reason for failure in both explantation and F/B-EVAR groups (75% vs 64%, respectively; P = .052). Type I endoleak was the most common endoleak reported in both groups, occurring more frequently in F/B-EVAR (64% vs 40%; P < .001); type II endoleak was more common in those undergoing open repair (28% vs 2%; P < .001). Graft migration (12% vs 26%; P = .005) and neck degeneration/disease progression (14% vs 59%; P < .001) were more prevalent in F/B-EVAR, but aneurysm enlargement was more common in explantation (68% vs 33%; P < .001). Thirty-day reintervention rates did not differ between F/B-EVAR and explantation (odds ratio, 0.6258; 95% confidence interval, 0.2-1.86; P = .4115); however, 30-day mortality was lower in the F/B-EVAR group (5% vs 10%; P = .0192). Similarly, aneurysm-related mortality was also lower in the F/B-EVAR group (hazard ratio, 0.0683; 95% confidence interval, 0.01-0.44; P = .0048). A subset analysis excluding emergencies and infections did not alter the lack of difference in terms of freedom from reinterventions (P = .1175), 30-day mortality (P = .6329), or aneurysm-related mortality (P = .7849). ConclusionsExplantation and F/B-EVAR are necessary options in treating patients with failed EVAR, and both techniques have competitive results. Different modes of failure may point to a preferred method of treatment; consequently, rescue of failed EVAR should be individualized according to each patient’s presentation and resources available.

FT08. Retrospective Review of Underlying Causes of Endovascular Aneurysm Repair Failure Requiring Open Conversion

Most endovascular aneurysm repair (EVAR) complications can be treated by endovascular means. However, some patients require open conversion (OC) after EVAR because of complications that are resistant to endovascular treatment. The frequency of OC after EVAR has been variously reported because of different follow-up duration and diagnostic program of the EVAR complications. Surgical morbidity and mortality associated with OC were reported to be significantly higher compared with the standard open surgical repair of abdominal aortic aneurysm. We attempted to search for underlying causes of EVAR failure requiring OC. OC was defined as surgical opening of the aneurysmal sac after EVAR regardless of aortic cross-clamping or stent graft removal. To find underlying causes of EVAR failure requiring OC, we retrospectively reviewed history of infection after EVAR, endovascular reintervention after EVAR, pre- and post-EVAR computed tomography images, and angiographic images during the EVAR procedure. Diagnosis and type of endoleak depended on computed tomography, ultrasound, and operative findings. For the diagnosis of endograft infection (EGI), we followed the Management of Aortic Graft Infection Collaboration (MAGIC) criteria (EJVES 2016;52:758-63). Twenty-three OCs (institutional, n = 8) were performed for 22 patients (median age, 75 years; male, 83%) at a mean 26 months (2-130 months) after EVAR during the past 14 years. Our institutional frequency of OC was 1.8% after standard EVAR. Indications for OC were end leak (n = 11 [48%]), EGI (n = 9 [39%]), aortic rupture (n = 4 [17%]; 1 intraoperative and 3 late ruptures), and continuous sac enlargement without evidence of endoleak (n = 2 [9%]). Endoleaks requiring OC were type IA (n = 5), type IB (n = 1), type IIIA (n = 1), and type IIIB (n = 2). Among nine EGIs, three (33%) patients presented with aortoenteric fistula or erosion. Among the patients with EGI, the infection source was identifiable in four (44%) patients, which included EVAR for patients with infected abdominal aortic aneurysm (n = 2) and coexisting psoas abscess at the time of EVAR (n = 2). Among five late EGIs, three patients showed a remote site infection source, including leg cellulitis, gingival abscess, and bacteremia. Among four aortic ruptures, one patient required OC because of intraoperative aortic rupture during EVAR. As a result of OC, we have experienced one (4%) surgical death and three early postoperative complications, including late midcolic artery rupture in type I neurofibromatosis, left colon ischemia, and acute renal insufficiency. We think that at least 73% of OCs due to endoleak, 44% of OCs due to EGI, and 25% of aortic ruptures are preventable by proper selection of EVAR candidates and careful endovascular technique.

Use of the Zenith Fenestrated platform to rescue failing endovascular and open aortic reconstructions is safe and technically feasible

ObjectiveProximal neck dilation is a serious long-term complication directly causing the failure of endovascular aneurysm repair (EVAR) and open surgical repair (OSR) of abdominal aortic aneurysms. However, the implantation of a fenestrated device presents the opportunity for proximal extension of the aortic reconstruction into a healthy segment while maintaining patency of the visceral vessels. The objective of this investigation was to report perioperative and follow-up outcomes using the Zenith Fenestrated (ZFEN; Cook Medical, Bloomington, Ind) aortic stent system in salvaging previous aortic repairs undergoing type IA endoleak or aneurysmal degeneration of the proximal neck. MethodsWe performed a retrospective review of a prospectively maintained institutional database capturing all fenestrated EVAR (FEVAR) cases with the ZFEN platform. Fenestrated cases were classified as primary FEVAR or reoperative FEVAR (rFEVAR) after previous EVAR or OSR. Cohort comparisons were performed using Fisher exact tests and Student t-tests for categorical and continuous variables, respectively. ResultsBetween October 2012 and March 2017, a total of 103 patients diagnosed with abdominal aortic aneurysm with an inadequate proximal seal zone for traditional EVAR were treated with ZFEN. In 12 patients, FEVAR was performed as a reoperation after previous EVAR (n = 6) or OSR (n = 6). The indications for rFEVAR were proximal neck dilation (>55 mm) after OSR (n = 6), type IA endoleak after EVAR (n = 5), and proximal neck dilation after EVAR without endoleak (n = 1). No difference in ability to achieve technical success was observed between primary FEVAR and rFEVAR (97.8% vs 100%; P = 1.00). In addition, there were no differences in estimated blood loss (363 vs 500 mL; P = .25) and intraoperative use of contrast material (97.3 vs 104.0 mL; P = .55). However, a significant increase in fluoroscopy time (61.1 vs 79.8 minutes; P = .04), radiation exposure (415.9 vs 606.3 rad; P = .02), and operative time (228.4 vs 287.6 minutes; P = .03) in the rFEVAR cohort was observed. In the 30-day perioperative period, there were no significant differences with regard to mortality (2.2% vs 0%; P = 1.0), major adverse cardiovascular events (5.5% vs 0%, P = 1.0), and stent-related adverse events (2.2% vs 0%; P = 1.0). There were no differences in rates of perioperative (5.5% vs 0%; P = 1.0) or follow-up reintervention after a mean follow-up duration of 20.8 months (18.6% vs 25.0%; P = .70). ConclusionsFEVAR with the ZFEN platform of failed and failing aortic reconstructions due to disease progression is safe and feasible without increased morbidity and mortality in select patients. These preliminary results support the inclusion of ZFEN as a treatment option for aortic reintervention.

Editor's Choice – Late Open Surgical Conversion after Endovascular Abdominal Aortic Aneurysm Repair

Late open surgical conversion following endovascular aneurysm repair (EVAR) may occur more frequently after performing EVAR in anatomy outside the instructions for use (IFU). This study reviews predictors and outcomes of late open surgical conversion for failed EVAR. This retrospective cohort study reviewed all EVARs performed at the Ottawa Hospital between January 1999 and May 2015. Open surgical conversions >1 month post EVAR were identified. Variables analysed included indication for conversion, pre-intervention AAA anatomy, endovascular device and configuration, operative technique, re-interventions, complications, and death. Of 1060 consecutive EVARs performed, 16 required late open surgical conversion. Endografts implanted were Medtronic Talent (n = 8, 50.0%), Medtronic Endurant (n = 3, 18.8%), Cook Zenith (n = 4, 25.0%), and Terumo Anaconda (n = 1, 6.2%). Eleven grafts were bifurcated (68.8%), five were aorto-uni-iliac (31.2%). The median time to open surgical conversion was 3.1 (IQR 1.0-5.2) years. There was no significant difference in pre-EVAR rupture status (1.4% elective, 2.1% ruptured, p=.54). Indications for conversion included: Type 1 endoleak with sac expansion (n=4, 25.0%), Type 2 endoleak with expansion (n=2, 12.5%), migration (n=3, 18.8%), sac expansion without endoleak (n=2, 12.5%), graft infection (n=3, 18.8%), rupture (n=2, 12.5%). Nine patients (56.2%) underwent stent graft explantation with in situ surgical graft reconstruction, seven had endograft preserving open surgical intervention. The 30 day mortality was 18.8% (n=3, all of whom having had endograft preservation). Ten patients (62.5%) suffered major in hospital complications. One patient (6.5%) required post-conversion major surgical re-intervention. IFU adherence during initial EVAR was 43.8%, versus 79.0% (p<.01) among uncomplicated EVARs. Open surgical conversion following EVAR results in significant morbidity and mortality. IFU adherence of EVARs later requiring open surgical conversion is markedly low. More data are required to elucidate the impact of increasing liberalisation of EVAR outside of IFU.

Strategies and Outcomes for Aortic Endograft Explantation

Failure of endovascular aneurysm repair (EVAR) requiring open conversion remains a major challenge. We analyzed indications for repair, operative strategies, and outcomes with a focus on iliac artery degeneration after endograft removal. A prospective, institutional database was reviewed to identify patients who underwent explantation of a failed EVAR device. Demographics, reason for failure, operative details including extent of endograft removal, and complications/survival were examined. Postexplantation computed tomography imaging was evaluated for iliac artery degeneration. Thirty-two patients underwent explantation from 2002 to 2017. Six patients were treated emergently for rupture. The majority were elderly (average age, 76 ± 8.5 years), white (100%) men (91%) who had their EVAR graft inserted 45.5 months (range, 0.3-86 months) before open conversion, usually at an outside institution (75%). Explanted endografts included nine AneuRx (Medtronic, Santa Rosa, Calif), nine Excluder (W. L. Gore & Associates, Flagstaff, Ariz), four Endurant (Medtronic), three Zenith (Cook Medical, Bloomington, Ind), three Powerlink/AFX (Endologix, Irvine, Calif), one Aorfix (Lombard Medical, Irvine, Calif), one Talent (Medtronic), and two unknown. Failure was due to endoleak in 81% (type I, 28%; type II, 28%; type III, 13%; type V, 13%), migration in 9%, infection in 6%, and occlusion/kinking in 3%. Prior attempt at endovascular EVAR salvage occurred in 12 (37.5%) patients. Operative approach was transabdominal in 69% and retroperitoneal in 31%. Initial aortic clamp position was supraceliac in 31%, suprarenal in 31%, and infrarenal in 38%. Most patients had complete removal of their endograft (n = 19 [59%]), with 22 (69%) having at least the iliac limbs removed. Grafts with suprarenal fixation were more likely to have the upper main body left in situ (67% vs 17%; P = .029). The 30-day mortality was 6.3% (3.8% elective, 16.7% ruptured), and 31% had a major complication. Of the 23 patients who had follow-up imaging, there was a trend for more iliac degeneration (>5 mm of growth) in those who had the iliac limbs removed (29.4% vs 0%; P = .184). Three patients with iliac limb removal required subsequent iliac endovascular intervention (two for rupture). Patients who presented with a rupture had a decreased 5-year overall survival (33%) compared with those who were converted electively (59%). Both complete and partial endograft explantation, albeit morbid procedures, can be performed safely. Postoperative imaging surveillance is important, especially if the endograft has been removed from the iliac arteries, as degeneration can occur.

A Systematic Review of Predictors of Reintervention After EVAR: Guidance for Risk-Stratified Surveillance.

Current surveillance protocols after endovascular aneurysm repair (EVAR) are ineffective and costly. Stratifying surveillance by individual risk of reintervention requires an understanding of the factors involved in developing post-EVAR complications. This systematic review assessed risk factors for reintervention after EVAR and proposals for stratified surveillance. A systematic search according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was performed using EMBASE and MEDLINE databases to identify studies reporting on risk factors predicting reintervention after EVAR and proposals for stratified surveillance. Twenty-nine studies reporting on 39 898 patients met the primary inclusion criteria for reporting predictors of reintervention or aortic complications with or without suggestions for stratified surveillance. Five secondary studies described external validation of risk scores for reintervention or aortic complications. There was great heterogeneity in reporting risk factors identified at the pre-EVAR, intraoperative, and post-EVAR stages of treatment, although large preoperative abdominal aortic aneurysm diameter was the most commonly observed risk factor for reintervention after EVAR. Existing data on predictors of post-EVAR complications are generally of poor quality and largely derived from retrospective studies. Few studies describing suggestions for stratified surveillance have been subjected to external validation. There is a need to refine risk prediction for EVAR failure and to conduct prospective comparative studies of personalized surveillance with standard practice.

Conical neck is strongly associated with proximal failure in standard endovascular aneurysm repair

ObjectiveHostile proximal aortic neck (HN) challenges the suitability for standard endovascular aneurysm repair (EVAR) of patients at high risk for “open” repair. However, there has been little if any focus placed on the individual role of the “nonlength” HN features in EVAR outcomes. The aim of this study was to evaluate their individual and potentially predictive role in outcomes of EVAR under HN conditions. MethodsData of 156 consecutive EVAR patients with short (<15 mm) HN, treated with the Endurant device (Medtronic Cardiovascular, Santa Rosa, Calif) at three European academic vascular centers between 2007 and 2015, were collected and retrospectively analyzed. All patients had at least one of the four well-known nonlength HN criteria (width >32 mm or bulge, angulation >60 degrees, reverse taper anatomy, and circumferential thrombus or calcification >50%) and underwent standard EVAR without additional techniques, such as use of chimney grafts or endoanchors. Primary end points were absence of type IA endoleak at 1 month and midterm follow-up and aneurysm sac stabilization or shrinkage. Secondary end points were 30-day mortality, overall survival, and secondary interventions related to EVAR. The study cohort was classified in two subgroups related to neck length (length <10 mm and length between 10 and 14 mm) as well as in two subgroups according to on-label or off-label stent graft use. ResultsMean clinical and radiologic follow-up was 41.1 ± 24.7 and 31.7 ± 19.0 months, respectively. Overall EVAR-related mortality was 1.9% (n = 3). The total type IA endoleak rate was 5.8% (n = 9). In four patients, the type IA endoleak was detected intraoperatively and solved by endovascular means. A type IA endoleak was detected in three patients at 1 month and in two patients at 2-year follow-up. During follow-up, five patients showed an increase of aneurysm diameter due to type II endoleak and were treated by secondary endovascular reinterventions. The total number of all EVAR-related secondary procedures in the midterm was 12 (7.7%). Univariate analysis showed that the center of treatment and the clinical or anatomic features were not associated with adverse outcomes. Multiple regression and Cox regression analysis of HN features revealed that reverse taper anatomy (conical neck) was the single and significantly associated predictor of proximal EVAR failure (P < .012). Width >32 mm, angulation >60 degrees, and calcification or thrombus were not associated with adverse outcomes. Analysis between HN length cohorts and between on-label and off-label subgroups revealed no difference in outcomes. ConclusionsA conical neck in hostile anatomies represents the single strongest factor associated with proximal failure of standard EVAR. This finding should be considered and highlighted apart from the length of the infrarenal neck to prevent midterm failure of standard EVAR.

Endovascular Aneurysm Sealing (EVAS) and Chimney EVAS in the Treatment of Failed Endovascular Aneurysm Repairs

Purpose: To assess the technical success and clinical outcome of reinterventions using the Nellix Endovascular Aneurysm Sealing (EVAS) System to treat complications after endovascular aneurysm repair (EVAR). Methods: Fifteen consecutive patients (mean age 79 years; 14 men) with prior EVAR were treated with EVAS between March 2014 and December 2015 at 2 institutions. The failed prior EVARs included 13 bifurcated endografts, 1 bifurcated graft plus fenestrated cuff, and 1 tube endograft. Endoleaks were the predominant indications: type Ia in 10 and type III in 5 (3 type IIIa and 2 type IIIb). All patients presented with progressive aortic aneurysms (median 7.85-cm diameter; range 6.5–11). Eight patients were treated on an urgent or emergency basis (6 symptomatic aneurysms and 2 contained ruptures). All patients underwent Nellix relining of the failed stent-graft; 10 had chimney (Ch) procedures in combination with EVAS (chEVAS) because the proximal landing zones were inadequate. Results: Technical success was 100%. All endoleaks were successfully sealed, and no additional intervention was required. No further endoleak after EVAS or chEVAS was recorded. Endobag protrusion occurred in 1 case without sequelae. One elderly patient with ruptured aneurysm died from multiple organ failure 2 months postoperatively. One renal artery guidewire injury led to nephrectomy because of active bleeding. No reinterventions, aneurysm-related mortalities, graft thrombosis, endoleaks, or chimney graft occlusions were observed during a median follow-up of 8 months (range 3–24). Conclusion: The present preliminary experience demonstrates that the use of EVAS/chEVAS is feasible for treatment of failed EVAR. This technique may be used as bailout or an alternative treatment when other established methods are infeasible or not available.

Failure mode analysis of the Endologix endograft

Type III (T-III) endoleaks following endovascular aneurysm repair (EVAR) remain a major concern. Our center experienced a recent concentration of T-III endoleaks requiring elective and emergency treatment and prompted our review of all EVAR implants over a 40-month period from April 2011 until August 2014. This report represents a single center experience with T-III endoleak management with analysis of factors leading to the T-III-related failure of EVAR. A retrospective review of all the operative reports, medical records, and computed tomography scans were reviewed from practice surveillance. Using Society for Vascular Surgery aneurysm reporting standards, we analyzed the morphology of the aneurysms before and after EVAR implant using computed tomography. Index procedure and frequency of reinterventions required to maintain aneurysm freedom from rupture were compared across all devices using SAS v 9.4 (SAS Institute, Inc, Cary, NC). Major adverse events (MAEs) requiring secondary interventions for aneurysm treatment beyond primary implant were analyzed for methods of failure. Aneurysm morphology of patients requiring EVAR was compared across all endograft devices used for repair. For purposes of MAE analysis, patients receiving Endologix (ELX) endograft were combined into group 1; Gore, Cook, and Medtronic endograft patients were placed into group2. Overall, technical success and discharge survival were achieved in 97.3% and 98% of patients regardless of device usage. There was no significant device related difference identified between patient survival or freedom from intervention. MAEs involving aneurysm treatment were over seven-fold more frequent with ELX (group 1) vs non-ELX (group 2) endografts (P< .01). Group 1 patients with aneurysm diameters larger than 65mm were associated with ahighly significant value for development of a T-III endoleak (odds ratio, 11.16; 95% confidence interval, 2.17, 57.27; P= .0038). While EVAR technical success and survival were similar across all devices, ELX devices exhibited an unusually high incidence of T-III endoleaks when implanted in abdominal aortic aneurysms with a diameter of more than 65mm. Frequent reinterventions were required for Endologix devices for prevention of aneurysm rupture due to T-III endoleaks.

Failure Mode Analysis of the Endologix Endograft

Objective Type III (T-III) endoleaks following endovascular aneurysm repair (EVAR) remain a major concern. Our center experienced a recent concentration of T-III endoleaks requiring elective and emergency treatment and prompted our review of all EVAR implants over a 40-month period from April 2011 until August 2014. This report represents a single center experience with T-III endoleak management with analysis of factors leading to the T-III-related failure of EVAR. Methods A retrospective review of all the operative reports, medical records, and computed tomography scans were reviewed from practice surveillance. Using Society for Vascular Surgery aneurysm reporting standards, we analyzed the morphology of the aneurysms before and after EVAR implant using computed tomography. Index procedure and frequency of reinterventions required to maintain aneurysm freedom from rupture were compared across all devices using SAS v 9.4 (SAS Institute, Inc, Cary, NC). Major adverse events (MAEs) requiring secondary interventions for aneurysm treatment beyond primary implant were analyzed for methods of failure. Aneurysm morphology of patients requiring EVAR was compared across all endograft devices used for repair. For purposes of MAE analysis, patients receiving Endologix (ELX) endograft were combined into group 1; Gore, Cook, and Medtronic endograft patients were placed into group 2. Results Overall, technical success and discharge survival were achieved in 97.3% and 98% of patients regardless of device usage. There was no significant device related difference identified between patient survival or freedom from intervention. MAEs involving aneurysm treatment were over seven-fold more frequent with ELX (group 1) vs non-ELX (group 2) endografts ( P P = .0038). Conclusions While EVAR technical success and survival were similar across all devices, ELX devices exhibited an unusually high incidence of T-III endoleaks when implanted in abdominal aortic aneurysms with a diameter of more than 65 mm. Frequent reinterventions were required for Endologix devices for prevention of aneurysm rupture due to T-III endoleaks.

Endovascular conversion into aorto-uniiliac configuration of acute failed endovascular aneurysm repair is associated with better one-year survival rates compared to open conversion

BackgroundOpen conversions (OC) due to failed endovascular repair of infrarenal abdominal aortic aneurysms (EVAR) are technically demanding because of preexisting prostheses and advanced aortic disease. This study evaluates the feasibility and outcomes of aorto-uniiliac endografting (AUI) as an alternative treatment option in acute failed EVAR. MethodsFrom March 1995 through February 2012, 26 patients underwent acute conversion of failed EVAR at our tertiary care university center. All data were prospectively entered in our institutional database. Outcomes included 30-day or in-hospital mortality, postoperative complications, and mid-term survival. ResultsDuring the investigation period, a total of 692 patients received EVAR at our institution, while five of the 26 patients with acute conversion (19.2%) had an initial EVAR at an outlying institution and were referred for treatment. Therefore, our estimated institutional rate of acute conversions was 3% (21 of 692 EVAR). OC were performed in 14 patients (53.8%), while 12 patients underwent AUI (46.2%). An average time of 20.3 months (median: 18.6; interquartile range Q1–Q3: 0.0–38.6) elapsed between the initial EVAR and the acute conversion. All acute AUI conversion procedures were completed successfully. The 30-day mortality following acute conversions was 42.3% and since the use of AUI, it could be reduced to 33.3%. Kaplan–Meier estimates revealed a survival advantage for AUI at one year (p = 0.046), but the benefit was lost by mid-term follow-up (p = 0.103). ConclusionsAUI for the treatment of acute failed EVAR represents a feasible and less invasive alternative to OC, and is associated with better one-year survival rates.

Numerical Simulation for Design Evaluation of Thoracic Stent Graft to Investigate the Migration Phenomena and Type 1a Endoleak of Thoracic Aneurysm

Migration and endoleak phenomena are considered to be the principal reasons for Endovascular Aneurysm Repair failure. Wide differences of opinion exist regarding the nature of these critical complications. They occur when there is non-complete and ineffective contact between the endograft ends and the wall of the blood vessel. A major goal of present work is to investigate, using the Finite Element Method, the effect of nitinol stent design on the overall effectiveness of contact and radial force. The specific-patient aneurysmal thoracic aorta are challenging. The optimized stent results show better contact stability to resist the migration. They also show a good compromise of stent design requirements (flexibility and stiffness). Moreover, the new design can also prevent the risk of folding or the collapse of stent struts by mitigating the energy of eccentric deformation caused by high angulation and oversizing.

Secondary modification into aortouniiliac configuration to salvage failed endovascular aneurysm repair is safe and effective but not associated with higher intervention rates during long-term follow-up

BackgroundReports of secondary modifications into aortouniiliac configuration to salvage-failed endovascular aneurysm repair (EVAR) are limited. We evaluated long-term results after these procedures and compared them with those after primary aortouniiliac endografting (AUE). MethodsA retrospective review of all EVAR performed from March 1995 until July 2011 was conducted. Patients were included when primary AUE (group I) or modification into aortouniiliac configuration (group II) was done. ResultsData analysis obtained 27 group I and 23 group II patients. Salvage of failed EVAR could be achieved in 96% of group II patients, and mortality was zero. Frequency of adverse events and amount of interventions to maintain aneurysm exclusion were not increased after secondary AUE. Kaplan–Meier estimates for long-term survival between groups were comparable (P = .36). ConclusionsSecondary AUE allows correction of graft-related endoleaks potentially leading to late aneurysm rupture. Complications and adverse events throughout long-term follow-up were not necessarily increased when compared with primary AUE.

Late rescue of proximal endograft failure using fenestrated and branched devices

Endovascular aneurysm repair (EVAR) will fail over time in a percentage of patients. Mechanical failure of the device, progression of aortic disease, or interface complications between the device and the native vasculature may contribute. Our aim was to evaluate the role of fenestrated and branched endografts as treatment options for failed devices. Between January 2001 and June 2013, 970 patients were enrolled into a physician-sponsored investigational device exemption (PSIDE) study and treated with a fenestrated/branched endograft. All patients treated for nonurgent proximal neck failure of an infrarenal endoprosthesis previously implanted during EVAR comprised the study group. Patients treated for a primary aneurysm within the PSIDE were evaluated as a comparison group to identify preoperative risk factors for failure. A retrospective review was undertaken to determine the details of the initial EVAR, whereas the prospective PSIDE database was used to assess outcomes of secondary treatment. Three-dimensional imaging techniques were used to define all morphologic measurements. Statistical analysis included comparisons between categoric variables with the χ(2) test and between continuous variables with the Wilcoxon rank sum test between patients with late failures and those with native aortic repair. Kaplan-Meier curves were used to analyze overall survival. Of 970 patients enrolled in the PSIDE, 54 (5.6%) had late failure of a prior endograft. Fenestrated/branched devices were used to address the failure in each patient. The etiology of failure was related to a proximal neck issue in all patients: type Ia endoleak in 38, stent migration in 18, neck degeneration in 28, or some combination of these factors. The endovascular rescue procedure took place a mean of 61 months after the primary procedure. The mean aneurysm diameter at reintervention was 67 mm. Patients requiring a secondary fenestrated procedure were younger at the time of their primary intervention (P = .039) and were more likely to have a history of chronic renal insufficiency (P = .05) compared with other patients in the PSIDE. Technical success rate in the study group was 85% (44 of 52). Successful stenting was achieved in 71 of 77 (92%) target vessels. Thirty-day mortality was 3.8% (two of 52). Fluoroscopy dose and operating time were longer in the rescue group (P = .07) than in the control group (P = .008). Secondary interventions were required in 36.5% (19 of 52) of patients. Our series demonstrates the risk for late failure after EVAR is greater in patients who are younger and have chronic renal impairment at the time of implantation. Branched and fenestrated repair after failed EVAR is more complex than repair in the native aorta. More research is needed to identify patients at higher risk of failure after EVAR to prevent the need for rescue in the future.

Fenestrated Stent-Grafts for Salvage of Prior Endovascular Abdominal Aortic Aneurysm Repair

To review our experience with fenestrated endovascular aneurysm repair (F-EVAR) to treat complications after previous standard infrarenal endovascular aneurysm repair (EVAR). A prospectively maintained database including all consecutive patients with juxtarenal abdominal aortic aneurysm that were treated with F-EVAR after failed previous EVAR within the period March 2002 to November 2012 at the University Medical Center of Groningen, Netherlands (up to October 2009), and the Klinikum Nürnberg Süd, Germany (from November 2009) was analyzed. Evaluated outcomes included initial technical success, operative mortality and morbidity, and late procedure-related events with regard to survival, target vessel patency, endoleak, renal function, and reintervention. A total of 26 patients (24 male, mean age 73.2 ± 6.5 years) were treated. All patients had proximal anatomies precluding endovascular reintervention with standard techniques. In 23 patients a fenestrated proximal cuff was used, and in three patients a bifurcated fenestrated stent graft. Technical success was achieved in 24 (92.3%) patients. One patient required on-table open conversion because of impossibility to retrieve the top cap as a result of twist of the ipsilateral limb. In the second patient the right kidney was lost due to inadvertent stenting in a smaller branch of the renal artery. Catheterization difficulties, all related to the passage through the limbs or struts of the previous stent graft, were encountered in 11 (42.3%) cases, including five (19.2%) patients with iliac access problems and six (23.1%) with challenging renal catheterization. Operative target vessel perfusion success rate was 94.6% (70/74). Operative mortality was 0%. Mean follow-up was 26.8 ± 28.5 months. No proximal type I endoleak was present on first postoperative CTA. The mean aneurysm maximal diameter decreased from 73 ± 20 mm to 66.7 ± 21 mm (p < .05). There were six late deaths, one of them aneurysm related. Estimated survival rates at 1 and 2 years were 94.1 ± 5.7% and 87.4 ± 8.4%, respectively. Patency during follow-up for the target vessels treated successfully with a fenestrated stent graft was 100% (70/70). Reintervention was required in four cases, including one acute conversion due to rupture, one for iliac limb occlusion and two for type Ib and II endoleak. Renal function deterioration was observed solely in the two cases of primary technical failure. F-EVAR represents a feasible option for the repair of juxtarenal abdominal aortic aneurysm after prior EVAR failure. It is advantageous in terms of mortality and less morbid than open surgery, but is associated with increased technical challenges because of the previously placed stent graft. Outcome seems related to initial technical success.

Improving Proximal Fixation and Seal with the HeliFx Aortic EndoAnchor

Endovascular aneurysm repair (EVAR) transformed the therapy for aortic aneurysms and introduced an era of widespread use for endovascular procedures in a variety of vascular beds. Although dramatic improvements in acute outcomes drove the early enthusiasm for EVAR, a realization that the long-term integrity of the endoprostheses used for EVAR were sometimes inferior to the results obtained with open surgical reconstruction dampened enthusiasm for their use in low-risk and younger patients who mandated long-term follow-up. While early EVAR failure modes are often related to technical aspects of the implantation, late failures are often related to the implant migrating from its original longitudinal position or losing wall apposition in the face of continued aneurysmal dilatation. Migration, or the failure of longitudinal fixation, results in gradual loss of aortic approximation and the eventual repressurization of the aneurysm sac with its attendant risks of growth and rupture. The inability of stent- and barb-based endovascular fixation to resist aortic dilatation at the site of fixation also represents a late failure mode that can result in aneurysm rupture. A variety of endostaples or endoanchors designed to replicate the function of an interrupted aortic suture have been proposed and tested to varying degrees over the years. The device designed and produced by Aptus EndoSystems, now called the HeliFx Aortic EndoAnchor is the only independent endovascular fixation device that has achieved significant clinical usage and Food and Drug Administration approval. The experience with this device is now more than 5 years and it is approved for use in the broad market across both Europe and the United States. This article will review the engineering and design concepts underlying the HeliFx device as well as the in vitro and in vivo results using this device. Finally, a discussion of the potential for technical, procedural, and endograft innovation based on the availability of endovascular suturing will be reviewed.

Proximal Type I Endoleak After Previous EVAR With Palmaz Stents Crossing the Renal Arteries: Treatment Using a Fenestrated Cuff

To report the use of a fenestrated cuff for endovascular treatment of a proximal type I endoleak after previous endovascular aneurysm repair (EVAR) that included 2 suprarenal cuffs and 2 Palmaz stents. A 71-year-old man had been treated for an infrarenal abdominal aortic aneurysm with a Powerlink stent-graft, 2 additional proximal cuffs with suprarenal fixation, and 2 Palmaz stents extending over the renal arteries. Follow-up demonstrated a type I endoleak and an increase in aneurysm size. A 2-stage endovascular approach featuring a fenestrated cuff was undertaken. Prior to the endoleak repair procedure, both renal arteries were catheterized and the Palmaz stent struts dilated. When the customized fenestrated cuff was available, it was successfully positioned with covered stents in the fenestrations, completely excluding the proximal type I endoleak. Fenestrated stent-grafting is a viable alternative to open repair after failed EVAR, even when previously implanted bare metal stents cross the renal orifices.

Aortomonoiliac Endografting after Failed Endovascular Aneurysm Repair: Indications and Long-term Results

ObjectivesTo present long-term results of endoleak/endograft migration treatment by aortomonoiliac (AMI) endografting after failed endovascular aneurysm repair (EVAR) of infrarenal abdominal aortic aneurysms. DesignPost hoc analysis of a prospectively gathered database at a tertiary care university hospital. Materials and methodsFrom March 1995 to November 2010, 23 patients were identified who underwent modification into AMI configuration after failed elective EVAR. Major causes for modification were type I (with/without endograft migration) or type III endoleaks with aneurysm expansion. An average increase in aneurysm size of 1.6 cm (range: −1.5 to 10.5 cm) since initial aneurysm treatment was observed. Interventional outcomes and long-term results were recorded for analysis. ResultsTechnical success rate of AMI endografting was 95.65% (n = 22). All except two endoleaks could be successfully sealed with this manoeuvre (94.44%). Median time to modification was 5.3 years (interquartile range Q1–Q3: 1.3–9.3 years). No intra-operative conversion to open surgery was necessary and mortality was 0%. Median follow-up was 44 months (interquartile range Q1–Q3: 17–69 months). ConclusionsTreatment of graft-related endoleaks/endograft migration by AMI endografting after failed EVAR represents a safe and feasible procedure. This approach broadens the minimal invasive opportunities of aneurysm treatment, and open surgical conversion may be avoided except in selected patients.