Zenith AAA endovascular graft: intermediate-term results of the US multicenter trial

Clinical Performance of the Low Profile Zenith Alpha Abdominal Endovascular Graft: 2 Year Results from the ZEPHYR Registry

OBJECTIVE

The midterm outcomes of the low profile Zenith Alpha Abdominal Endovascular Graft from the ZEnith alPHa for aneurYsm Repair (ZEPHYR) registry are reported.

METHODS

The ZEPHYR registry is a physician initiated, multicentre, non-randomised, core laboratory controlled, prospective registry. Inclusion criteria were patients with a non-ruptured abdominal aortic aneurysm with a maximum diameter ≥ 50 mm or enlargement > 5 mm within 6 months, with a site reported infrarenal neck length of ≥ 10 mm and with the intention to electively implant the Zenith Alpha abdominal endograft. Patients from 14 sites across Germany, Belgium, and the Netherlands were included. The primary endpoint was treatment success, defined as technical success and clinical success. Technical success was defined as successful delivery and deployment of the endograft in the planned position without unintentional coverage of internal iliac or renal arteries, with successful removal of the delivery system. Clinical success was defined as freedom from aneurysm sac expansion > 5 mm, type I or type III endoleaks, aneurysm rupture, stent graft migration > 10 mm, open conversion, and stent graft occlusion.

RESULTS

Three hundred and forty-seven patients were included in the ZEPHYR registry. The median clinical follow up was 743 days (interquartile range [IQR] 657, 806) with a median imaging follow up of 725 days (IQR 408, 788). Treatment success at 6 months, 1, and 2 years was 92.5%, 90.4%, and 85.3%, respectively. Freedom from secondary intervention was 94.3%, 93.4%, and 86.9%, respectively. The predominant reason for secondary intervention was limb complications. Freedom from limb occlusion (per patient) at 6 months, 1, and 2 years was 97.2%, 95.8%, and 92.5%, respectively. Univariable and multivariable Cox regression analyses could not identify any independent predictor for limb complications.

CONCLUSION

While treatment success is comparable with other commercially available grafts, the rate of limb complications at 2 years is of concern. The manufacturer's instructions for use should be followed closely. Further studies are necessary to investigate the root cause of the increased rate of limb complications with the Zenith Alpha Abdominal Endovascular Graft.

A Systematic Review of the Recruitment and Outcome Reporting by Sex and Race/Ethnicity in Stent Device Development Trials for Endovascular Abdominal Aortic Aneurysm Repair

BACKGROUND

Women and racial/ethnic minority groups have been shown to experience poor outcomes after endovascular aortic aneurysm repair (EVAR). One potential reason is the rare inclusion of these populations in initial phases of device development. The objective of this systematic review is to understand enrollment and outcome reporting by sex and race/ethnicity in industry-funded EVAR device development trials.

METHODS

MEDLINE, PubMed, and Embase were searched from inception to January 2022 without language restrictions using the following terminology: "stent", "graft", "endograft", "device", and "abdominal aortic aneurysm" (AAA).

CLINICALTRIALS

gov was also searched from inception to January 2022 for "AAA." Two independent reviewers screened and extracted data. All phase I-III and postmarket evaluation trials that included patients ≥18 years of age, who underwent EVAR were assessed. Participation-to-prevalence ratios (PPRs) were calculated to estimate representation of participants by sex and race/ethnicity in trials compared with their share of disease burden.

RESULTS

Among the 4,780 retrieved articles, 55 industry-funded trials met inclusion criteria for this review. A total of 51 trials (93%) reported enrollment by sex/gender, and only 7 trials (13%) reported enrollment by race/ethnicity of the participants. A median of 19 (interquartile range [IQR]: 4.5, 51) women participants were recruited compared to 171 (IQR: 57, 311.5) men, and 17 (IQR: 7.5, 21.5) racial/minority patients were recruited compared to 241 (IQR: 123, 463.5) White participants. Women represent 16.6% of the disease population, and the median PPR is 0.62 (IQR: 0.42, 0.88), which has remained constant over time (Figure 1). None of the device trials reported outcomes based on sex/gender or race/ethnicity.

CONCLUSIONS

This systematic review highlights the disparities in recruitment and outcome reporting based on sex and race/ethnicity in EVAR device development trials. While most trials may be underpowered to study these differences, recent registry studies show differential outcomes based on sex and race/ethnicity of vascular patients. Therefore, it is imperative to include and report outcomes in these participants, starting from the initial device development phases to improve generalizability of device-use and understand sources of variation in device performance.

One-year safety and effectiveness of the Alto abdominal stent graft in the ELEVATE IDE trial

OBJECTIVE

This study reports the results of a prospective, multicenter trial designed to evaluate the safety and effectiveness of the polymer based Endologix Alto Stent Graft System in treating abdominal aortic aneurysms (AAAs), with sealing 7 mm below the top of the fabric in aortic neck diameters from 16 to 30 mm.

METHODS

Seventy-five patients were treated with Alto devices between March 2017 and February 2018 in 16 centers in the United States for infrarenal AAAs (max diameter ≥5.0 cm in diameter or size increase by 0.5 cm in 6 months or diameter ≥1.5 times the adjacent normal aorta). Patients were followed for 30 days, 6 months, and 1 year by clinical evaluation and computed tomography and abdominal x-ray imaging. Treatment success was defined as technical success and freedom from AAA enlargement, migration, type I or III endoleak, AAA rupture or surgical conversion, stent graft stenosis, occlusion, kink, thromboembolic events, and stent fracture attributable to the device requiring secondary intervention through 12 months. Preoperative characteristics, perioperative variables, follow-up clinical evaluations, and radiographic examination results through the first 1 year were analyzed.

RESULTS

The mean patient age was 73 years, with 93% of patients being male. The 30-day major adverse event rate was 5.3%. At 1 year, the primary endpoint was met with a treatment success rate of 96.7%. Through 1-year post-treatment, all-cause mortality was 4.0%. No AAA-related mortality occurred. AAA enlargement was 1.6%, type I endoleak rate was 1.4%, with 100% freedom from type III endoleaks, device migration, device fracture, stent occlusion, or AAA rupture. The device-related secondary intervention rate was 2.7%.

CONCLUSIONS

This prospective study demonstrates the Endologix Alto is safe and effective in treating AAAs with appropriate anatomy at 1 year. The safety endpoint is met by a 5.3% 30-day major adverse event rate, whereas the effectiveness endpoint is met by a treatment success rate of 96%.

Female Sex Is Associated With Reintervention and Mortality Following Elective Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVE

While sex differences in endovascular abdominal aortic aneurysm repair (EVAR) outcomes are increasingly reported, but contributing factors remain without consensus. We investigated disparities in sex-specific outcomes following elective EVAR at our institution and evaluated factors that may predispose females to increased morbidity and mortality.

METHODS

A retrospective chart review of all patients undergoing elective EVAR from 2011 to 2020 at a suburban tertiary care center was performed. The primary outcomes were five-year survival and freedom from reintervention. Fisher's exact test, t-tests, and Kaplan-Meier analysis using the rank-log test investigated associations between sex and outcomes. A multivariable Cox proportional hazard model controlling for age and common comorbidities evaluated the effect of sex on survival and freedom from reintervention.

RESULTS

Two hundred and seventy-three patients underwent elective EVAR during the study period, including 68 (25%) females and 205 (75%) males. Females were older on average than males (76 years vs. 73 years, p= <0.01) and were more likely to have chronic obstructive pulmonary disease (COPD; 38% versus 23%, p=0.01), require home oxygen therapy (9% versus 2%, p=0.04) or dialysis preoperatively (4% versus 0%, p=0.02). Distribution of other common vascular comorbidities was similar between the sexes. Thirty-day readmission was greater in females than males (18% versus 8%, p=0.02). Females had significantly lower survival at five years (48% ± 7.9% versus 65% ± 4.3%, p<0.01) and significantly lower one-year (89% ± 4.1% for females vs. 94% ± 1.7% for males, p=0.01) and five-year freedom from reintervention (69% ± 8.9% versus 84% ± 3.3%, p=0.02). On multivariable analysis, female sex (hazard ratio [HR]: 1.8, 95% confidence interval [CI]: 1.1-2.9), congestive heart failure (HR: 2.2, 95% CI: 1.2-3.9) and age (HR: 1.1, 95% CI: 1.0-1.1) were associated with 5-year mortality. Female sex remained as the only variable with a statistically significant association with five-year reintervention (HR: 2.4, 95% CI: 1.1-4.9).

CONCLUSIONS

Female sex was associated with decreased five-year survival and increased one and five-year reintervention following elective EVAR. Data from our institution suggests factors beyond patient age and baseline health risk likely contribute to greater surgical morbidity and mortality for females following elective EVAR.

Sex-specific criteria for repair should be utilized in patients undergoing aortic aneurysm repair

OBJECTIVE

Female patients are more likely to undergo repair of intact and ruptured abdominal aortic aneurysm (AAA) at smaller aortic diameter compared with male patients. By adjusting for inherent anatomic differences between sexes, aortic size index (ASI) and aortic height index (AHI) may provide an additional method for guiding treatment. We therefore analyzed sex-specific criteria for AAA repair using aortic diameter, ASI, and AHI.

METHODS

We identified all patients who underwent AAA repair between 2003 and 2019 in the Vascular Quality Initiative database. The Dubois and Dubois formula was used to calculate body surface area; aortic diameter was divided by body surface area to calculate ASI. Aortic diameter was divided by height to calculate AHI. Cumulative distribution curves were used to plot the proportion of patients who underwent repair of ruptured aneurysm according to aortic diameter, ASI, and AHI. Multivariable logistic regression modeling was used to identify the association of female sex with perioperative mortality and any major postoperative complication.

RESULTS

We identified 55,647 patients, of whom 12,664 were female (20%). For both intact and rupture repair, female patients were older, less likely to undergo endovascular aneurysm repair, and more likely to have comorbid conditions. Female patients underwent repair at smaller median aortic diameter compared with male patients for intact (5.4 vs 5.5 cm; P < .001) and rupture repair (6.7 vs 7.7 cm; P < .001). However, ASI was higher in female patients for both intact (3.1 vs 2.7 cm/m²; P < .001) and rupture repair (3.8 vs 3.7 cm/m²; P < .001), whereas AHI was higher in female patients for intact repair (3.3 vs 3.1 cm/m; P < .001) but lower for rupture repair (4.1 vs 4.3 cm/m; P < .001). When analyzing the cumulative distribution of rupture repair in male patients, 12% of rupture repairs were performed at an aortic diameter below 5.5 cm. To achieve the same proportion of rupture repair in female patients, the repair diameter was only 4.9 cm. However, when ASI and AHI were used, female and male patients both reached 12% of rupture repair at an ASI of 2.7 cm/m² and an AHI of 3.0 cm/m.

CONCLUSION

Our study provides data to strongly support the sex-specific 5.0-cm aortic diameter threshold suggested for repair in female patients by the Society for Vascular Surgery. The high percentage of patients undergoing rupture repair below 5.5 cm in male patients and 5.0 cm in female patients highlights the need to better identify patients at risk of rupture at smaller aortic diameters.

Epidemiology of abdominal aortic aneurysms

Abdominal aortic aneurysm (AAA) disease remains a major source of morbidity in developed countries and can progress to life-threatening rupture if left untreated, with exceedingly high mortality. The goal of AAA management is to identify and electively repair AAAs before rupture. AAA disease burden and outcomes have improved over time with declining tobacco use and advancements in care across patients' disease course. The introduction of endovascular AAA repair, in particular, has allowed for elective AAA repair in patients previously considered too high risk for open surgery and has contributed to lower rates of AAA rupture over time. However, these improved outcomes are not universally experienced, and disparities continue to exist in the detection, treatment, and outcomes of AAA by sex, race, and ethnicity. Mitigating these disparities requires enhanced, focused efforts at preventing disease, promoting health, and delivering appropriate care among an increasingly diverse patient population.

Reporting standards for endovascular aortic repair of aneurysms involving the renal-mesenteric arteries

Endovascular aortic aneurysm repair of complex aortic aneurysms requires incorporation of side branches using specially designed aortic stent grafts with fenestrations, directional branches, or parallel stent grafts. These techniques have been increasingly used and reported in the literature. The purpose of this document is to clarify and to update terminology, classification systems, measurement techniques, and end point definitions that are recommended for reports dealing with endovascular repair of complex abdominal and thoracoabdominal aortic aneurysms involving the renal and mesenteric arteries.

Endurant stent graft demonstrates promising outcomes in challenging abdominal aortic aneurysm anatomy

OBJECTIVE

We aimed to assess the 5-year safety and effectiveness outcomes of patients enrolled in the Endurant Stent Graft Natural Selection Global Post Market Registry (ENGAGE) who were treated outside the approved indications for use (IFU) of the Endurant stent graft.

METHODS

Our primary outcome measure was 12-month treatment success, defined as successful endograft delivery and deployment and the absence of type I or III endoleak, stent migration or limb occlusion, late conversion, and abdominal aortic aneurysm diameter increase or rupture. Secondary outcome measures included 30-day all-cause mortality, major adverse events, secondary procedures, technical observations, aneurysm-related mortality, and all-cause mortality within 12 months.

RESULTS

Demographic characteristics of ENGAGE patients treated outside (225 [17.8%]) and within (1038 [82.2%]) the IFUs were similar, except that female patients comprised a much higher percentage of the outside IFU group (19.1% vs 8.7%; P < .001). The outside IFU group presented with lower rates of coronary artery disease and cardiac revascularization and a greater number of symptomatic patients compared with the within IFU group (21.3% vs 15.0%; P = .020). Technical success was achieved in more than 99% of all patients. The outside and within IFU groups showed a comparable and low occurrence of uncorrected type I (0.9% vs 1.2%; P = 1.00) and type III endoleak (0.4% vs 0.3%; P = .54) immediately after device implantation. The 5-year freedom from type IA endoleaks was 89.4% vs 96.7% (P < .0001) for those patients outside and within the IFUs, respectively, although both groups had similar type III endoleaks through 5 years (P = .61). Stent graft limb occlusion estimated overall survival, and freedom from aneurysm-related mortality and endovascular interventions were comparable in both patient groups through the 5-year follow-up. The Kaplan-Meier estimates at 5 years showed a trend for low but increased need for type I or III endoleak correction procedures in the outside IFU group compared with the within IFU group (7.2% vs 5.2%; P = .099).

CONCLUSIONS

Differences were not observed in all-cause mortality, aneurysm-related mortality, and secondary procedures between within and outside IFU patients through a 5-year follow-up in the ENGAGE registry. Proximal necks with angulation or diameters outside the IFUs were the most common reasons for patients identified as being outside IFU, and the cohort had increased incidence of type IA endoleaks. Despite the challenges presented from the broad range of aortic and abdominal aortic aneurysm morphologies, the Endurant stent graft showed promising 5-year outcomes.

Female sex is associated with comparable 5-year outcomes after contemporary endovascular aneurysm repair despite more challenging anatomy

BACKGROUND

Women with abdominal aortic aneurysms less often meet anatomic criteria for endovascular repair and experience worse perioperative and long-term survival.

METHODS

We compared long-term survival, aneurysm-related mortality, and rates of endoleaks and reinterventions between male and female patients in the Endurant Stent Graft Natural Selection Global Postmarket Registry (ENGAGE) using 2:1 propensity score matching.

RESULTS

There were 1130 male patients and 133 female patients, yielding 399 patients after matching (266 male patients, 133 female patients). Female patients were older, with smaller aneurysms, smaller iliac arteries, and shorter, more angulated necks, and they were more often treated outside the device instructions for use (all P < .001). Through 5 years, female patients experienced overall mortality comparable to that of well-matched male patients (34% vs 38%, respectively; hazard ratio, 0.89 [0.61-1.29]; P = .54) and lower aneurysm-related mortality (0% vs 3%; P = .047). Female patients experienced higher rates of any postoperative type IA endoleak through 5 years (10% vs 1%; P < .001) but comparable rates of secondary endovascular procedures (14% vs 16%; P = .40). Female sex was independently associated with significantly higher risk of long-term type IA endoleaks (hazard ratio, 4.8 [1.2-20.8]; P = .04), even after accounting for anatomic factors. No female patient experienced aneurysm rupture during follow-up, and only one female patient underwent conversion to open repair.

CONCLUSIONS

Despite more challenging anatomy, female patients in the ENGAGE registry had long-term outcomes comparable to those of male patients. However, female patients experienced higher rates of type IA endoleaks. Although standard endovascular aneurysm repair remains a viable solution for most women, whether high-risk patients may be better served with open surgery, custom-made devices, EndoAnchors (Aptus Endosystems, Sunnyvale, Calif), or chimneys is worthy of further study.

Anatomic Suitability of Iliac Branched Devices for Chinese Patients with Abdominal-Iliac Aortic Aneurysm

BACKGROUND

Preserving internal iliac flow is the key to preventing ischemic complications during endovascular aneurysm repair (EVAR). The aim of this study is to determine the morphological features of abdominal aortic aneurysms (AAAs) that have been reported in clinical trials in Chinese patients to identify unique features of iliac branched systems.

METHODS

The data for patients who had common iliac aneurysms suitable for imaging review from 2014 to 2017 at 1 institution in China were reviewed. Three-dimensional workstations were used to measure the centerline diameters and lengths of aortoiliac structures, which were screened for suitability for both Cook iliac branch devices (IBD) and Gore iliac branch endoprosthesis (IBE).

RESULTS

A total of 102 lesions of common iliac aneurysms were suitable for imaging review. The anatomic standards for the Gore IBE and Cook IBD were met by 13.7% (14/102) and 9.8% (10/102) of the cases, respectively, and 3 cases were suitable for both devices. The most common cause of not meeting the criteria was the same for both the Cook IBD (78.4%) and Gore IBE (48.03%), which was a limitation of the diameter of the target internal iliac artery. Of the 92 lesions excluded from the Cook IBD trial, 11 (11.9%) were eligible for the Gore IBE trial. Likewise, 7.95% (7/88) of the lesions excluded from the Gore IBE trial would have been eligible for the Cook IBD graft. In a practice that is able to enroll patients in both trials, a total of 20.6% (21/102) of the patients would be eligible for treatment, based on the anatomic criteria.

CONCLUSIONS

The high incidence of iliac artery involvement in AAAs makes EVAR more complicated. Cook IBD and Gore IBE are only suitable for the treatment of a total of 20.6% Chinese patients based on the anatomic criteria. A limitation in the diameter of the target internal iliac artery is the most common cause of failure to meet the criteria for both devices. Future generations of iliac branch technologies should be designed with diameter accommodations for the hypogastric branch stent to reach a wider group of patients with aortoiliac aneurysmal disease.

Late graft failure is rare after endovascular aneurysm repair using the Zenith stent graft in a cohort of high-risk patients

OBJECTIVE

Device-specific data on the long-term efficacy of endovascular aneurysm repair (EVAR) are limited by the constant evolution of stent graft design. Whereas some modifications, such as barb-mediated fixation, probably enhance durability, others, such as thin-walled fabric, are of less certain benefit. The purpose of this study was to examine 15 years of a single-center experience of EVAR using the Zenith stent graft (Cook Medical, Bloomington, Ind).

METHODS

Retrospective analysis was conducted of 325 high-risk patients who underwent elective EVAR with Zenith stent grafts between October 1998 and December 2005 under a physician-sponsored investigational device exemption. Patients' charts and death registries were reviewed to identify late stent graft failures and causes of death. Late stent graft failures were defined as type I or type III endoleaks; enlarging aneurysm sac requiring revision; and limb kinking or occlusion, stent graft infection, renal artery occlusion, or aneurysm rupture occurring >30 days after the index procedure.

RESULTS

The mean age at treatment was 75.9 ± 7.4 years, and 300 of 325 (92%) were men. The mean aneurysm diameter was 60 ± 9 mm, and the median main body stent graft diameter was 28 mm (range, 22-32 mm). During a median follow-up time of 5.6 years (interquartile range, 2.6-8.7 years), there were six (2%) aneurysm-related deaths caused by the following: one stent graft infection, one infection of a femoral-femoral bypass graft placed after limb occlusion, one infection of a stent graft placed to treat a type IB endoleak, and three aneurysm ruptures. There were 19 (6%) late stent graft failures occurring at a median time of 4.0 years (range, 39 days-14.6 years) after the procedure. Patients with late stent graft failure were more likely to have had impaired renal function (creatinine concentration ≥2 mg/dL; 21% vs 6%; P = .03) and less likely to have had cardiac disease (42% vs 67%; P = .04) at the time of the index procedure. There was no significant association between late stent graft failure and age, sex, aneurysm size, stent graft diameter, diabetes, smoking, or lung disease. Kaplan-Meier estimated overall survival was 60% at 5 years, 29% at 10 years, and 12% at 15 years. Kaplan-Meier estimated freedom from aneurysm-related mortality was 98% at 5 years, 97% at 10 years, and 97% at 15 years.

CONCLUSIONS

Late-occurring stent graft failures and aneurysm-related death are rare after EVAR using the Zenith stent graft, especially in high-risk patients whose comorbidities diminish life expectancy.

Open aortic surgery volume experience at a regionalized referral center and impact on Accreditation Council for Graduate Medical Education trainees

OBJECTIVE

The objective of this study was to review our institute's open aortic surgery volume experience and its impact on Accreditation Council for Graduate Medical Education trainees.

METHODS

A review was conducted of the vascular surgery department's operative database for all cases that underwent aortic aneurysm repair, whether open aortic repair (OAR), endovascular aneurysm repair (EVAR), or fenestrated EVAR (FEVAR). We also reviewed our graduating trainees' case logs. In the setting of our regionalized referral center, all patients who underwent open or endovascular aortic intervention between 2010 and 2014 at our main campus were included. The total number of aortic procedures performed by our graduation trainees was determined. All aortic aneurysm interventions, both open and endovascular (both EVAR and FEVAR), were included. The main outcome measures were the total number of aortic interventions, any change in trends of intervention, and the total number of open aortic cases that our graduation trainees had.

RESULTS

During the 5-year period analyzed, a total of 1389 abdominal aortic aneurysm repair procedures were performed by OAR, EVAR, and FEVAR. Of those, 462 were OARs, representing 33.2% of the total; 440 were EVARs, representing 31.6%; and 487 were FEVARs, representing 35.2%. For all OAR procedures, there was a significant increase in the proportion of these cases over time (P = .014). The total number of EVAR and FEVAR cases performed annually during this time did not change, whereas the number of OAR cases has increased. Of the OARs, 59.3% were performed for juxtarenal aneurysms, whereas 22.9% involved type IV thoracoabdominal aortic aneurysms. On average, graduating vascular surgery trainees performed 23.1 OARs before graduation (range, 19-26).

CONCLUSIONS

In contrast to the documented national trend of decreased OAR, our institute continues to see increased OAR relative to EVAR and FEVAR. Moreover, we theorized that the preservation of OAR volume in our program and other similar institutions might offer a practical solution to the challenge of addressing vascular surgery training in aortic surgery by OAR, EVAR, and FEVAR. Inclusive discussions at the national and international levels are needed to reach consensus regarding the future of vascular surgery training and key issues, such as additional, mandatory, subspecialized training in OAR and FEVAR for both residents and fellows who wish to receive certification in OAR; creation of centers of excellence for open aortic surgery that would centralize OAR and direct trainees to those centers for their needed training; and possibly development of new training strategies whereby single cases can be shared among trainees with alternating roles as exposure and closure vs repair.

The state of complex endovascular abdominal aortic aneurysm repairs in the Vascular Quality Initiative

BACKGROUND

Endovascular repair of complex abdominal aortic aneurysms has become increasingly common, but reports have mostly been limited to single centers and single devices.

METHODS

We studied all endovascular repairs of complex abdominal aortic aneurysms (zone 6 or caudal) from 2014 to 2018 in the Vascular Quality Initiative. This included all commercially available fenestrated endovascular aneurysm repair (FEVAR), chimney/snorkel repairs, and physician-modified endografts (PMEGs), exclusive of investigational device exemptions and clinical trial devices. We used inverse probability-weighted multilevel logistic regression to compare rates of perioperative outcomes including death, acute kidney injury (AKI), and major adverse cardiac events (MACEs; the composite of death/stroke/myocardial infarction) and Cox regression for long-term mortality.

RESULTS

During the study period, surgeons performed 1396 complex endovascular repairs: 1308 (94%) elective, 63 (4.5%) for symptomatic aneurysms, and 25 (1.8%) for rupture. The number of centers performing complex endovascular repairs expanded steadily from 39 in 2014 to 81 in 2017. There were 880 FEVAR (63%), 256 PMEG (18%), and 260 chimney/snorkel repairs (19%). In elective cases, 3214 visceral vessels were incorporated and revascularized; 120 repairs (9%) involved one vessel, 481 (38%) repairs involved two vessels, 560 (44%) involved three vessels, and 113 (9%) involved four vessels. The mean number of arteries incorporated was 2.5 ± 0.8, with PMEGs involving the most arteries (3.3 ± 0.8 for PMEG vs 2.5 ± 0.6 for FEVAR and 1.9 ± 0.9 for chimney/snorkel; P < .001). PMEGs were used to treat more extensive aneurysms, and more incorporated the celiac and superior mesenteric arteries. There was no change in aneurysm extent, but the length of proximal seal extended over time. Chimney/snorkel cases employed more arm or neck access, had longer procedure times, and used more contrast material. Rates of perioperative death (3.4% for FEVAR vs 2.7% for PMEG vs 6.1% for chimney/snorkel; P = .13) and AKI (17% vs 18% vs 19%; P = .42) were similar, but chimney/snorkel was associated with higher rates of stroke (0.8% vs 0.9% vs 3.3%; P = .03) and MACEs (6.1% vs 5.4% vs 11.7%; P = .02). After adjustment, rates of perioperative death, AKI, and overall complications remained similar, but chimney/snorkel was associated with significantly higher odds of stroke (odds ratio [OR], 7.3 [1.5-36.4]; P = .015), myocardial infarction (OR, 18.7 [2.6-136.8]; P = .004), and MACEs (OR, 11.1 [2.1-58.9]; P = .005). Overall survival after elective repair was 91% at 1 year and 88% at 3 years, with no difference between repair types in crude or adjusted analysis.

CONCLUSIONS

The Vascular Quality Initiative provides a unique opportunity to study the real-world application and outcomes of complex endovascular aneurysm repair. Perioperative morbidity appears to be higher after chimney/snorkel repair, but further study is needed to confirm these findings and to establish the durability of these novel technologies.

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.

Three-Year Results of the Endurant Stent Graft System Post Approval Study

BACKGROUND

Long-term data following endovascular aneurysm repair (EVAR) exist but are limited to endografts that are no longer in use. The aim of the ENGAGE Post Approval Study is to describe the long-term safety and effectiveness data following EVAR using the Endurant stent graft system.

METHODS

From August 2011 to June 2012, 178 patients were enrolled and treated with the Endurant stent graft system. Clinical and radiologic data were prospectively collected and analyzed. The primary end point was abdominal aortic aneurysm (AAA)-related mortality, and secondary end points were overall mortality, endoleak, secondary interventions, and device-related complications. Kaplan-Meier estimates were used for late outcomes.

RESULTS

A total of 178 patients underwent EVAR with the Endurant stent graft across 24 centers (82% men; median age 71, interquartile range [IQR] 66-79). Median aortic diameter was 55 mm (IQR 51-58 mm). There was a 98.9% technical success rate. Three-year clinical and radiographic follow-up data were available for 87% and 74% of patients, respectively. Median follow-up was 37 months (IQR 30-38 months). Three-year aneurysm-related mortality rate was 1.1%, with 2 deceased patients in the perioperative period. All-cause mortality rate at 3 years was 13%. No patients suffered from aneurysm rupture or underwent conversion to open repair through 3 years of follow-up. Only 11 patients (6.2%) had undergone reintervention at 3 years. Younger age was associated with reintervention (HR 3.3 per younger decade, 95% confidence interval 1.3-7.6, P < 0.01), but neck diameter, length, and angulation were not significantly associated with reintervention.

CONCLUSIONS

The Endurant stent graft system provides a safe, durable approach to treating infrarenal AAA. No patients experienced late rupture or aneurysm-related mortality, and only 1 in 16 patients underwent reintervention by 3 years. The rate of reintervention with the Endurant graft appears to be lower than other contemporary grafts, despite more liberal "Instructions For Use" parameters, but further research including direct graft comparisons will be necessary to guide appropriate graft selection.

Late open conversion after endovascular repair of abdominal aneurysm failure: Better and easier option than complex endovascular treatment

AIM

Conversion to open repair becomes the last option in case of endovascular repair of abdominal aneurysm failure, when radiological interventional procedures are unfeasible. While early conversion to open repair generally derives from technical errors, aetiopathogenesis and results of late conversion to open repair often remain unclear.

METHODS

We report data from our Institute's experience on late conversion to open repair. Twenty-two late conversion to open repairs out of 435 consecutive patients treated during a 18 years period, plus two endovascular repair of abdominal aneurysms performed in other centres, are analysed. The indication for conversion to open repair was aneurysm enlargement because of type I, type III, type II endoleak and endotension. Even if seven cases (23%) had shown an initial aneurysmal shrinkage, in a later phase, the sac began to enlarge again. In 12 patients, conversion to open repair was the last chance after unsuccessful secondary endovascular procedures.

RESULTS

Three cases (12.5%) were treated in emergency. Aortic cross-clamping was only infrarenal in 10 cases, only or temporarily suprarenal in 14 and temporarily supraceliac in 9 cases, for 19 total and 5 partial endograft excisions. Two patients died for Multiple Organ Failure (MOF), on 42nd (endovascular repair of abdominal aneurysm infection) and 66th postoperative day. No other conversion to open repair-related deaths or major complications were revealed by follow-up post-conversion to open repair (mean: 68 months ranging from 24 to 180 months).

CONCLUSION

Late conversion to open repair is often an unpredictable event. It represents a technical challenge: specifically, the most critical point is the proximal aortic clamping that often temporarily excludes the renal circulation. In our series, conversion to open repair can be performed with a low rate of complications. In response to an endovascular repair of abdominal aneurysm failure, before applying complex procedures of endovascular treatment, conversion to open repair should be taken into account.

Prospective cohort 20 years after endovascular treatment for abdominal aortic aneurysm

OBJECTIVE

To describe the factors associated with survival 20 years after endovascular treatment of an abdominal aortic aneurysm (AAA) in a single center.

METHODS

Prospective cohort of asymptomatic patients with an infrarenal aortic aneurysm treated with a bifurcated endovascular graft (Talent) between June 1997 and August 2008. Cox proportional hazard multivariable regression was used for analysis of independent risk factors for survival. Kaplan-Meier curves were done with the long-rank test. P < .05 was considered significant.

RESULTS

We followed 229 patients, 184 without an endoleak and 45 with an endoleak. Ages ranged between 52 and 89 years, and the mean diameter of the aneurysm was 59.51 ± 14.6 mm. Implantation of the endovascular graft was possible in 99% of the patients. The 30-day mortality rate was 3.4%. In the Cox regression, age <73 years (hazard ratio [HR], 0.42; 95% confidence interval [CI], 0.27-0.64), aneurysm size ≤55 mm (HR, 0.62; 95% CI, 0.40-0.95), male sex (HR, 0.17; 95% CI, 0.05-0.52), American Society of Anesthesiologists surgical risk category I and II vs III and IV (HR, 0.51; 95% CI, 0.34-0.75), and aneurysm size reduction ≤3 mm after treatment (HR, 2.23; 95% CI, 1.11-4.51) were significantly correlated with the survival of the patients followed in this long-term case series.

CONCLUSIONS

This 20-year prospective cohort included patients with an AAA treated with a bifurcated endovascular graft (Talent) at a university hospital in Brazil. This study supports that sex, age, aneurysm size, aneurysm size reduction, and American Society of Anesthesiologists surgical risk category are significantly correlated with patient survival after endovascular treatment of the AAA.

Comparison of Endovascular Stent Grafts for Abdominal Aortic Aneurysm Repair in Medicare Beneficiaries

BACKGROUND

Increased renal complications have been suggested with suprarenal stent grafts, but long-term analyses have been limited. Therefore, the purpose of this study was to evaluate the effect of endograft choice on perioperative and long-term outcomes.

METHODS

We compared Medicare beneficiaries undergoing endovascular abdominal aortic aneurysms repair from 2005 to 2008 with endografts with infrarenal fixation and a single docking limb (AneuRx, Excluder) to those with suprarenal fixation and 2 docking limbs (Zenith), or a unibody configuration (Powerlink). Propensity score weighting accounted for differences in patient characteristics among the different graft formations, and perioperative mortality, complications, and length of stay and 4-year rates of survival, rupture, and reintervention were compared.

RESULTS

Forty-six thousand one hundred seventy-one Medicare beneficiaries were identified including 11,002 (24%) with suprarenal fixation, 32,909 (71%) with infrarenal fixation, and 2,260 (5%) with a unibody graft. After propensity score weighting, there were no significant differences in patients' baseline clinical and demographic characteristics. The suprarenal fixation patients had higher rates of perioperative mortality (1.7% vs. 1.3%, P < 0.01), renal failure (6.0% vs. 4.7%, P < 0.001), and mesenteric ischemia (0.7% vs. 0.4%, P < 0.01) and longer length of stay (3.4 days vs. 3.0 days, P < 0.001) compared with patients with infrarenal fixation. Unibody grafts had higher rates of renal failure (5.9% vs. 4.7%, P < 0.001), mesenteric ischemia (1.0% vs. 0.4%, P < 0.001), and conversion to open repair (0.7% vs. 0.1%, P < 0.001) compared to those with infrarenal fixation and single docking limbs. At 4 years, mortality remained slightly higher with suprarenal compared to infrarenal fixation (30% vs. 29%, P = 0.047), although these patients had fewer conversions to open repair (0.6% vs. 0.9%, P = 0.03) and aneurysm-related reinterventions (10% vs. 12%, P < 0.01). At 4 years, unibody grafts had more aneurysm-related interventions compared to infrarenal fixation grafts (15% vs. 12%, P < 0.01) but fewer conversions to open repair (0.4% vs. 0.9%, P = 0.02). Late rupture did not differ among the groups.

CONCLUSIONS

Compared to infrarenal fixation devices, patients who underwent EVAR with suprarenal fixation had higher perioperative mortality and renal complications but fewer reinterventions including conversion, while the unibody graft had more perioperative complications and aneurysm-related reinterventions, but fewer conversions to open repair. Although these differences could be explained by selection bias, these data suggest that further comparative effectiveness analyses should be performed to understand the outcomes following EVAR with suprarenal fixation and unibody grafts.

Editor's Choice - Renal complications after EVAR with suprarenal versus infrarenal fixation among all users and routine users

BACKGROUND

Previous studies comparing endografts with suprarenal and infrarenal fixation for endovascular abdominal aortic aneurysm repair (EVAR) have found conflicting results and did not account for differences in patient selection. This study aims to evaluate the differences in outcomes among surgeons who routinely use either suprarenal or infrarenal fixation, as well as all surgeons in the Vascular Study Group of New England (VSGNE).

METHODS

All patients undergoing EVAR in the VSGNE from 2003 to 2014 were identified. All ruptured aneurysms, repairs with concomitant procedures, and infrequently used stent grafts (<50) were excluded. Suprarenal endografts included Talent, Zenith, and Endurant; infrarenal endografts included AneuRx and Excluder. Grafts were compared among surgeons who used only one type of endograft (suprarenal or infrarenal) for >80% of cases, as well as all surgeons. Multivariate regression and Cox hazard models were utilised to account for patient demographics, comorbidities, operative differences, and procedure year.

RESULTS

This study identified 2574 patients (suprarenal, 1264; infrarenal, 1310) with 888 endografts placed by routine users (suprarenal, 409; infrarenal, 479). There were no differences in baseline comorbidities, including the estimated glomerular filtration rate, between suprarenal and infrarenal fixation, or between patients with endografts placed by routine and non-routine users. Patients treated with suprarenal endografts received more contrast than all users (102 mL vs. 100 mL, p = .01) and routine users (110 mL vs. 88 mL, p < .01), but other vascular and operative details were similar. Among all users, patients treated with suprarenal grafts had higher rates of creatinine increase >.5 mg/dL (3.7% vs. 2.0%, p = .01), length of stay >2 days (27% vs. 19%, p < .01), and discharge to a skilled nursing facility (9.2% vs. 6.7%, p = .02). There were no differences in 30 day or 1 year mortality. Following adjustment, suprarenal stent grafts remained associated with an increased risk of renal deterioration (OR 2.0; 95% CI 1.2-3.4) and prolonged length of stay (OR 1.8; 95% CI 1.4-2.2). Among routine users, suprarenal fixation was also associated with higher rates of renal dysfunction (3.7% vs. 1.3%, p = .02; OR 2.9; 95% CI 1.1-7.8).

CONCLUSION

Despite potential differences in patient selection, endografts with suprarenal fixation among all users and routine users were associated with higher rates of renal deterioration and longer length of hospital stay. Longer-term data are needed to determine the duration and severity of renal function decline and to identify potential benefits of decreased migration or endoleak.

Comparison of Renal Complications between Endografts with Suprarenal and Infrarenal Fixation

OBJECTIVES

Surgeons have multiple grafts options available for the endovascular treatment of abdominal aortic aneurysm (EVAR), and some hypothesize that suprarenal fixation endografts may result in higher rates of renal complications than infrarenal endografts. This study aimed to compare the outcomes of contemporary suprarenal and infrarenal endografts.

METHODS

The Targeted Vascular Module of the National Surgical Quality Improvement Project was utilised to identify patients undergoing EVAR for infrarenal aneurysm from 2011 to 2013. Pre-operative and operative variables and 30 day outcomes were compared among suprarenal (Zenith and Endurant) and infrarenal fixation devices (Excluder). Renal complications included creatinine increase > 2 mg/dL or new dialysis, as defined by NSQIP. Multivariate regression was completed to account for patient demographics, comorbidities, and operative characteristics.

RESULTS

A total of 3587 patients were evaluated including 2273 (63%) with suprarenal grafts and 1314 (37%) with infrarenal grafts. Patients with suprarenal grafts were less commonly white (84% vs. 88%, p < .01) and more commonly male (83% vs. 80%, p = .03). There were no differences in age or comorbidities. Renal complications (1.1% vs. 0.1%, p < .01) and length of stay more than 2 days (34% vs. 25%, p < .01) occurred more commonly after suprarenal fixation. After adjustment, suprarenal grafts had significantly higher rates of renal complications (OR, 12.0; 95% CI, 1.6-91) and length of stay more than 2 days (OR, 1.4; 95% CI, 1.2-1.7).

CONCLUSION

Overall rates of renal complications following EVAR are low. Patients selected for suprarenal stent grafts are at increased risk of renal complications and prolonged length of stay, which may be due to selection bias, deployment techniques, or the presence of a bare stent overlying the renal arteries. Further studies are necessary to evaluate the mechanism and duration of renal dysfunction and important long-term outcomes of interest.

Editor's Choice - Comparison of Renal Outcomes in Patients Treated by Zenith® Fenestrated and Zenith® Abdominal Aortic Aneurysm Stent grafts in US Prospective Pivotal Trials

OBJECTIVE/BACKGROUND

Fenestrated endovascular repair (FEVAR) has been used to treat complex abdominal aortic aneurysms (AAAs). The risk of renal function deterioration compared with infrarenal endovascular aortic repair (EVAR) has not been determined.

METHODS

Patients with preserved renal function (estimated glomerular filtration rate [eGFR] > 45 mL/minute) enrolled in two prospective, non-randomised studies evaluating Zenith fenestrated and AAA stent grafts were matched (1:2) by propensity scores for age, sex, hypertension, diabetes, and pre-operative eGFR. Sixty-seven patients were treated by FEVAR and 134 matched controls treated by EVAR. Mean follow-up was 30 ± 20 months. Outcomes included acute kidney injury (AKI) defined by RIFLE and changes in serum creatinine (sCr), eGFR, and chronic kidney disease (CKD) staging up to 5 years.

RESULTS

AKI at 1 month was similar between groups, with > 25% decline in eGFR observed in 5% of FEVAR and 9% of EVAR patients (p = .39). There were no significant differences in > 25% decline in eGFR at 2 years (FEVAR 20% vs. EVAR 20%; p > .99) or 5 years (FEVAR 27% vs. EVAR 50%; p = .50). Progression to stage IV-V CKD was similar at 2 years (FEVAR 2% vs. EVAR 3%; p > .99) and 5 years (FEVAR 7% vs. EVAR 8%; p > .99), with similar sCr and eGFR up to 5 years. During follow-up, there were more renal artery stenosis/occlusions (15/67 [22%] vs. 3/134 [2%]; p < .001) and renal related re-interventions (12/67 [18%] vs. 4/134 [3%]; p < .001) in patients treated by FEVAR. Rate of progression to renal failure requiring dialysis was low and identical in both groups (1.5% vs. 1.5%; p > .99).

CONCLUSION

Aortic repair with FEVAR and EVAR was associated with similar rates of renal function deterioration in patients with preserved pre-operative renal function. Renal related re-interventions were higher following FEVAR, although net changes in renal function were similar in both groups.

Management of Abdominal Aortic Aneurysm: A Decade of Progress

Since the world was first introduced to the concept of endovascular aneurysm repair by Parodi's landmark procedures in 1990, stent-grafts have assumed a prominent role in the management of abdominal aortic aneurysm. Most modern systems are trackable, accurate, and secure. The resulting endovascular procedure is safe, durable, effective, and versatile. Perhaps the most significant increment in the applicability of the endovascular technique was achieved by the development of bifurcated stent-grafts, which dispensed with inadequate distal aortic implantation sites. Additional branches and fenestrations now permit endovascular repair in cases of thoracoabdominal, pararenal, juxtarenal, and bilateral iliac aneurysms. These advances in device performance have been accompanied by a rapid dissemination of necessary skills, leading to the development of a new superspecialty of vascular therapy, with elements of vascular surgery, interventional radiology, and interventional cardiology.

Endovascular vs Open AAA Repair: Does Size Matter?

Since the natural tendency of the aorta is to increase in diameter and tortuosity with age and since abdominal aortic aneurysms (AAAs) increase in diameter and length over time, encroaching on the renal and hypogastric orifices, early repair of AAAs (when =4.0 cm) may allow greater applicability of the endovascular option because of more favorable aortoiliac morphology. Patients who present at an older age with larger AAAs should be more likely to be anatomically excluded from endovascular AAA repair. Over a 42-month period, 317 consecutive patients referred with aortoiliac aneurysms (infrarenal AAA =4.0 cm) were evaluated by one of the authors (SGL) for endovascular vs open repair based on computed tomography (CT) and angiographic imaging. The 10 anatomic exclusion criteria were those applicable to the Zenith ® endograft (Cook, Inc), which currently is the most anatomically inclusive of the aortic endografts in commercial use in the United States. Based on their aortoiliac morphology, 212 patients were excluded from endovascular repair and 105 were included as acceptable anatomic candidates. Age, AAA size, and the reason(s) for exclusion were recorded for each patient. By use of Student's t test and logistic and linear regression analyses, the groups were compared by age, AAA size, and age + size. There was no significant difference in patient age or AAA size distribution between the group of patients excluded from endovascular repair based on aortoiliac morphology compared to those who met the inclusion criteria. Patients with small AAAs (4.0–5.4 cm) had similar age distribution as those with large (=5.5 cm) AAAs. The majority of patients (87%) were excluded based on proximal aortic neck morphology. The presence of aortoiliac morphology that precludes endovascular repair is independent of patient age or AAA size at presentation. A patient presenting with a small (4.0–5.4 cm) AAA is not more likely to be a candidate for endovascular repair than a patient with a large AAA.

Impact of Gender on the Outcome of Endovascular Aortic Aneurysm Repair Using the Zenith Stent-Graft: Midterm Results

Purpose:

To analyze the 2-year outcomes of female patients after endovascular aortic aneurysm repair (EVAR) with the Zenith AAA Endovascular Graft.

Methods:

A retrospective analysis was conducted of data from the US Zenith multicenter trial and the Zenith female registry on 40 women (10.9%, study group) and 326 men (89.1%, control group) enrolled. All patients had completed their 2-year follow-up. Primary study endpoints were survival, aneurysm rupture, and conversion rate. Significance was assumed if p<0.05.

Results:

Overall rates of mortality (12.5% for women versus 13.2% for men, p=0.94) and aneurysm rupture (2.5% for women versus 0% for men, p=0.11) were comparable between groups. Conversion to open repair within 2 years was significantly more frequent in women compared to men (7.5% versus 0.6%, p=0.01). The incidence of endoleaks of any type was equivalent between groups at 2 years (13.3% for women versus 6.9% for men, p=0.30). No difference was observed in the need for secondary interventions (15% for women versus 13.5% for men, p=0.81) or aneurysm dilatation >5 mm (10.5% for women versus 2.3% for men, p=0.10). None of the patients developed device migration .10 mm or required intervention for migration.

Conclusion:

While women underwent conversion to open repair more frequently compared to men at 2 years post EVAR, there was no difference in survival, freedom from aneurysm rupture, or need for secondary interventions between groups. As in men, the Zenith AAA Endovascular Graft provides reliable protection from aneurysm rupture and aneurysm-related death in women in a midterm follow-up.

Natural History of the Iliac Arteries after Endovascular Abdominal Aortic Aneurysm Repair and Suitability of Ectatic Iliac Arteries as a Distal Sealing Zone

Purpose:

To investigate the natural history of dilated common iliac arteries (CIA) exposed to pulsatile blood flow after endovascular abdominal aortic aneurysm repair (EVAR) and the suitability of ectatic iliac arteries as sealing zones using flared iliac limbs.

Methods:

Follow-up computed tomograms of 102 CIAs in 60 EVAR patients were investigated. Diameter changes in CIAs ≤16 mm (group 1) were compared with changes in vessels where a dilated segment >16 mm in diameter continued to be exposed to pulsatile blood flow (group 2). Within group 2, cases in which the stent terminated proximal to the dilated artery segment (2a) were compared with those that had been treated with a flared limb (2b).

Results:

The mean CIA diameter increased by 1.0±1.0 mm in group 1 (p<0.001 versus immediately after EVAR) and by 1.5±1.7 mm in group 2 (p<0.001 versus immediately after EVAR) within an average follow-up of 43.6±18.0 months. Diameter increase was more pronounced in dilated CIAs (p=0.048), and it was not significantly different between groups 2a and 2b (p=0.188). No late distal type I endoleak or stent-graft migration associated with CIA ectasia was observed.

Conclusion:

Dilatation of the CIA is significant after EVAR, and it is more pronounced in ectatic iliac arteries. Although ectatic iliac arteries appear to be suitable sealing zones in the short term, continued follow-up is mandatory.

Aortoduodenal Fistula after Abdominal Aortic Stent Graft Presenting with Extremity Abscesses

Aortoenteric fistula (AEF) has been described after endovascular stent graft repair of abdominal aortic aneurysms (EVAR). AEF after EVAR has been associated with aneurysm growth, endoleak, migration, and aortic inflammation. We report a patient with an AEF presenting 2 years after EVAR with two abscesses in the right leg. A computed tomographic scan showed a gas-filled thrombus lining the right limb of his graft. At conversion, no endoleak, device migration, or residual aneurysm sac was found. AEF can occur after endoluminal stent graft (ELG) in the absence of aneurysm growth, endoleak, migration, or inflammation. AEF can cause ELG infection and extremity infection.

Current aortic endografts for the treatment of abdominal aortic aneurysms

Endovascular Aneurysm Repair is a widely adopted method of treatment for patients with abdominal aortic aneurysms. The minimally invasive approach offered with EVAR has become popular not only among physicians and patients, but in the medical device industry as well. Over the past 25 years the global market for aortic endografts has increased rapidly, resulting in a wide range of devices from various companies. Currently, there are seven endografts approved by the FDA for the treatment of abdominal aortic aneurysms. These devices offer a wide range of designs intended to increase inclusion criteria while decreasing technical complications such as endoleak and migration. Despite advances in device design, secondary interventions and follow-up requirements remain a significant issue. New devices are currently being studied in the U.S. and abroad and may significantly reduce complications and secondary interventions.

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.

Endovascular treatment of renal artery occlusion caused by aortic stentgraft migration

Renal function impairment during interventional procedures became a real clinical problem. Contrast related nephropathy is the most common cause of renal failure, however, the procedure-related technical troubles may cause unexpected renal dysfunction.Technical failure of EVAR resulting in acute renal dysfunction is presented. The postprocedural occlusion of the right renal artery was treated in chimney technique. Early reintervention allowed the kidney preservation and renal function restoration. It is impossible to avoid all the complications following treatment of aortic aneurysm, but they can be anticipated and comprehensively treated in collaboration with other specialists.

Surgical infrarenal "neo-neck" technique during elective conversion after EVAR with suprarenal fixation

OBJECTIVES

Conversion of a previous endovascular aneurysm repair (EVAR) with suprarenal fixation is a challenging situation even in the elective setting. The outcomes of a technique based on preservation of the first proximal covered stent of the endograft, used as a "neo-neck" for proximal anastomosis, are presented.

METHODS

From 2001 to 2014, nine patients underwent elective conversion of a previous suprarenally fixed EVAR. After supraceliac clamping, the aneurysm sac was opened and the endograft identified; the fabric was cut beyond the first covered stent together with its native aortic wall in order to create a "neo-neck." An aortic balloon was inflated into the visceral aorta to avoid back bleeding. A Dacron bifurcated tube graft (Intergard, Maquet) was then sutured to the neo-neck mimicking endobanding, passing the stitches into the aortic wall and the first covered stent.

RESULTS

The mean age was 68 years (range, 52-84 years). The stent grafts removed were four Zenith (Cook Medical), three Endurant (Medtronic), and two E-vita (Jotec). The indication for conversion was type 1A (n = 2), type 2 (n = 2), and type 3 (n = 1) endoleak, complete endograft thrombosis (n = 2), and abdominal pain with sac enlargement with no radiological sign of endoleak (n = 2). Blood loss was 1,428 mL (range 500-3,000 mL); the visceral ischemic time to perform the proximal anastomosis was 23.5 min ± 2.3 min). The post-operative complication rate was 11% (n = 1/9) related to a case of sac wall bleeding requiring re-intervention; mortality at 30 days was 0%. At 22 months (range, 8-41) the computed tomography angiogram demonstrated no signs of leaks or anastomotic pseudoaneurysm.

CONCLUSION

Preservation of the proximal covered stent of an endograft with suprarenal fixation used as an infrarenal "neo-neck" with incorporation of the aorta to the suture line during elective surgical explantation simplifies the procedure, and can be achieved with very low early morbidity and mortality; furthermore, it seems to be durable over mid-term follow up.

Image fusion performed with noncontrast computed tomography scans during endovascular aneurysm repair

We report two endovascular aneurysm repair procedures achieved under image fusion guidance accomplished with noncontrast injected preoperative computed tomography scans. Such use of this advanced imaging application reduces contrast media injection volume (respectively, 27 and 24 mL throughout the patients' hospital course). No changes in creatinine clearance occurred after the procedures. Contrast-enhanced ultrasound imaging confirmed technical success in both cases.

Infective Etiology Affects Outcomes of Late Open Conversion After Failed Endovascular Aneurysm Repair

Purpose: To retrospectively review all patients undergoing late open conversion (LOC) after endovascular aneurysm repair (EVAR) in order to identify any clinical or technical predictors of poor outcome. Methods: Twenty-six consecutive patients (24 men; mean age 74.7±8.3 years) underwent LOC between June 2006 and April 2013 at our institution. The mean interval from index EVAR to LOC was 40.4±29.2 months (range 5–93 months). The indication for LOC was endoleak in 14 (54%) patients and infection in 12 (46%): 2 (8%) patients with endoleak had a ruptured aneurysm and 6 (23%) patients with infection had a recurrent secondary aortoesophageal fistula (sAEF). Results: In all 12 cases of infection and in 12 of 14 endoleaks, the entire endograft was explanted. A rifampin-soaked Dacron silver graft was implanted in all patients with infection. Patients with any infection and with recurrent AEF required more blood units than patients with endoleak (6.40 vs. 1.86, p=0.045; 6.76 vs. 1.86, p=0.0036, respectively). Compared with endoleak, the duration of conversions in the setting of infection (274 vs. 316 minutes, p=0.42) and recurrent sAEF (274 vs. 396 minutes, p=0.021) was longer. All patients with recurrent sAEF died at a mean 3.0±2.5 days after LOC from proximal anastomosis disruption and hemorrhagic shock (n=2), myocardial infarction (n=2), acute stroke (n=1), or persistent sepsis (n=1). Perioperative mortality was significantly higher in patients with endograft infection (6/12, p=0.002) and in cases of supraceliac cross-clamping (4/6, p=0.003). The association of infection with supraceliac cross-clamping was a strong predictor for perioperative mortality (p<0.001). Conclusion: In our experience, endograft infection led to greater perioperative mortality after LOC. Recurrent aortoenteric fistula in association with supraceliac cross-clamping is a strong predictor of poor outcome. Patients surviving the perioperative period may have good chances of long-term survival.