Long-term survival after endovascular and open repair in patients with anatomy outside instructions for use criteria for endovascular aneurysm repair.

BACKGROUND: Randomized controlled trials of long-term survival for infrarenal abdominal aortic aneurysms have compared open surgical repair (OSR) with endovascular aneurysm repair (EVAR) in patients with suitable aortic anatomy for EVAR. However, in clinical practice, patients who do not meet instructions for use (IFU) criteria are often still treated by EVAR despite that some studies show higher graft-related adverse events. The goal of this study was to compare the long-term survival of EVAR and OSR in patients with anatomy outside IFU criteria for EVAR. METHODS: This multicenter retrospective cohort study included patients with at least one anatomic IFU violation for EVAR undergoing either elective EVAR or elective OSR for abdominal aortic aneurysm. Demographics, anatomic data, and follow-up data of patients were collected from three academic centers from 2003 to 2016. Device-specific IFU were used for EVAR patients, whereas generic IFU for EVAR were applied to the OSR patients. The primary outcomes were 30-day mortality and long-term all-cause mortality. Secondary outcomes were aneurysm-related mortality and perioperative complications at 30 days. Kaplan-Meier survival and Cox proportional hazards modeling were performed. Inverse propensity score weights were used to adjust for differences in treatment selection. RESULTS: The study population included 202 EVAR patients and 224 OSR patients with at least one anatomic IFU violation for EVAR. EVAR patients were older (78.1 ± 7.3 vs 70.9 ± 7.0 years; P < .001) and less likely to be hypertensive (69.3% vs 79.0%; P = .02) compared with OSR patients. OSR patients were more likely to have proximal aortic neck IFU violations (75.0% vs 47.1%; P < .001) and were less likely to have iliac IFU violations (65.2% vs 79.2%; P < .001). All-cause mortality was 37.6% in the EVAR group and 24.1% in the OSR group with a median follow-up time of 5.2 (3.5-7.2) and 5.4 (2.8-9.3) years, respectively (P < .002). Kaplan-Meier survival analysis revealed a significant association between patients undergoing OSR and increased long-term survival (log-rank P < .0001). When adjusted for possible confounders and weighted for propensity for treatment through Cox hazard modeling, the association remained significant (hazard ratio, 0.6; 95% confidence interval, 0.4-0.9). Aneurysm-related mortality was 3.5% in the EVAR group and 2.2% in the OSR group during long-term follow-up (P < .001). CONCLUSIONS: Our study identified that patients with IFU violations have higher overall long-term survival with open surgery compared with EVAR. Caution should be applied in considering standard EVAR for patients with anatomy outside of IFU.

Editor's Choice - Infrainguinal Bypass Following Failed Endovascular Intervention Compared With Primary Bypass: A Systematic Review and Meta-Analysis.

OBJECTIVES: Patients with infrainguinal peripheral arterial disease often undergo multiple revascularisation procedures. Although many centres have adopted an endovascular first approach, some are reluctant to do so for fear of compromising the outcomes of any subsequent bypasses. All studies that compared the outcomes of primary infrainguinal bypass with bypass after failed endovascular intervention were analysed. METHODS: A systematic review was conducted of MEDLINE, EMBASE, and CENTRAL databases for studies comparing outcomes of primary infrainguinal bypass with bypass after failed endovascular intervention for peripheral arterial disease. Abstracts and full text studies were screened independently by two reviewers with data abstraction done in duplicate. Dichotomous outcome measures were reported using the OR and 95% CI, and pooled using random effects models. RESULTS: Abstracts were screened (2,528), with 50 selected for full text review. Of these, 15 studies involving 11,886 patients met the inclusion criteria. Pooling the results of studies comparing primary bypass with bypass after failed endovascular intervention showed no significant difference in 30 day mortality (OR 1.00; 95% CI 0.65-1.54), or 30 day amputation rates (OR 1.26; 95% CI 0.95-1.65). Interestingly, one year amputation free survival was higher in the patients who had primary bypass (OR 1.30; 95% CI 1.10-1.52) compared with patients who had bypass after failed endovascular therapy. There was also worse one year primary patency (OR 1.65; 95% CI 1.04-2.62) for patients with prior failed endovascular intervention. The review demonstrated a trend towards higher rates of early graft occlusion (OR 4.54; 95% CI 0.97-21.28). CONCLUSIONS: Meta-analysis of the existing literature comparing primary bypass with bypass following failed endovascular intervention shows worse one year amputation free survival and worse primary patency in those patients who undergo bypass after failed endovascular intervention. There is also a trend towards higher rates of early graft occlusion, although these results were not statistically significant. These conclusions are limited by observational study design, inconsistent patient selection, and significant heterogeneity between studies.

Preoperative point-of-care ultrasound and its impact on arteriovenous fistula maturation outcomes.

OBJECTIVE: Duplex ultrasound as a preoperative assessment tool in the clinic may help identify anatomic factors predictive of fistula maturation. Preoperative point-of-care ultrasound (POCUS) offers surgeons an alternative to routine formal vein mapping as it can be performed by the operator during the initial clinic visit. We sought to determine the impact of POCUS as an adjunct to physical examination on arteriovenous fistula maturation. METHODS: All consecutive patients undergoing first-time dialysis access creation from December 2007 to December 2014 were retrospectively reviewed. Surgeons who routinely use POCUS to assess preoperative maximal vein diameter and quality were compared with surgeons who relied only on physical examination. All access and patency definitions were in accordance with the Society for Vascular Surgery's reporting standards. The effects of POCUS on fistula maturation rate and fistula abandonment were analyzed using logistic regression, controlling for comorbidities of the patient, anticoagulant use, and location of fistula. RESULTS: A total of 316 patients were included in the study; 250 patients were assessed exclusively with physical examination, and 66 patients underwent preoperative ultrasound examination by the vascular surgeon in the clinic. The primary failure rate in the ultrasound group was 18% compared with 47% (P < .001) in the group of patients who did not undergo ultrasound examination. In patients without preoperative ultrasound, there were higher rates of new access creation (31% vs 9%; P < .001) and fistula abandonment (66% vs 39%; P < .001). Multivariable analysis demonstrated that fistulas created without preoperative ultrasound were associated with a 3.56 greater risk of failure (95% confidence interval, 1.67-7.59; P = .001) compared with fistulas in the POCUS group. Similarly, the rate of fistula abandonment was 2.63 times higher (95% confidence interval, 1.38-5.05; P = .003) when ultrasound was not used preoperatively. Time to functional fistula maturation was better in the ultrasound group (P < .001). At 1 year, 12% of fistulas in the ultrasound group and 32% in the clinical examination group had yet to be cannulated. Secondary patency at 1 year was better in the POCUS group at 73% compared with 59% in the group with no preoperative ultrasound (P = .01). CONCLUSIONS: POCUS as an adjunct to physical examination for dialysis access patients leads to decreased rates of primary failure, new access creation, and fistula abandonment compared with patients who undergo only physical examination. Ultrasound examination improved times to functional fistula maturation and secondary patency. Further studies are required to compare POCUS with formal preoperative vein mapping for arteriovenous fistula planning.

Any nonadherence to instructions for use predicts graft-related adverse events in patients undergoing elective endovascular aneurysm repair.

BACKGROUND: A variety of devices exist for endovascular aneurysm repair (EVAR). Device-specific instructions for use (IFU) detail anatomic constraints to application and deployment of devices and are developed from rigorous bench testing. Nonadherence to IFU occurs frequently to avoid open surgery. The purpose of this study was to determine if IFU violations are associated with increased risk of graft-related adverse events (GRAEs) during follow-up. METHODS: This multicenter retrospective observational study included patients undergoing elective endovascular repair for abdominal aneurysmal disease with three different devices. Demographics, anatomic data, and follow-up data were collected on patients from 2005 to 2014. IFU violations were device specific and included neck diameter, length, and angulation and iliac artery diameter and length. GRAEs included a composite outcome of reintervention, migration, endoleak (type II excluded), rupture, limb occlusion, sac growth, and aneurysm-related mortality during the follow-up period. Kaplan-Meier survival and Cox proportional hazards modeling were performed. Any IFU violations as well as neck-specific IFU violations were analyzed. RESULTS: In 461 patients undergoing EVAR, 43.8% had at least one IFU violation. Patients with IFU violations were more likely to have peripheral vascular disease (12.4% vs 7.3%) and were less likely to be male (78.7% vs 90.3%). The most frequent IFU violations included diameter deviations of the neck (15.2%) and of the iliac artery (21.4%). Overall, the GRAE rate was 12.8%. Median follow-up time was 1.9 and 2.1 years for patients with and without an IFU violation, respectively. Kaplan-Meier survival revealed a significant association between the presence of an IFU violation and GRAEs (log-rank, P = .031). When adjusted for clinical variable through Cox hazard modeling, the association remained significant (hazard ratio 1.8; 95% confidence interval, 1.05-3.1). When neck-specific violations were considered independently, Kaplan-Meier survival (log-rank, P = .003) and Cox modeling (hazard ratio, 2.2; 95% confidence interval, 1.2-4.0) revealed a significant association between neck-specific IFU violation and GRAEs. CONCLUSIONS: A total of 43.8% of patients undergoing EVAR had a device-specific IFU violation, indicating that implanters are pushing the boundaries of device capabilities. Our study identified that any IFU violation was significantly associated with GRAEs over time. Caution should be applied to patients being considered for EVAR when IFU deviations exist.

Explaining endograft shortening during endovascular repair of abdominal aortic aneurysms in severe aortoiliac tortuosity.

OBJECTIVE: During endovascular aneurysm repair (EVAR), severely tortuous aortoiliac anatomy can alter the deployment and conformability of the endograft. The accuracy of treatment length measurements is commonly recognized to be affected by severe tortuosity. However, the exact mechanism of the postintervention length discrepancy is poorly understood. The objective of this study was to determine the mechanism of how severe aortoiliac tortuosity influences the endograft and native aorta during EVAR and its impact on the distal sealing zone. METHODS: A prospectively collected vascular surgery database was retrospectively reviewed at a university-affiliated medical center to identify the study patients. Patients who underwent EVAR with the main body device deployed on the side of the severely tortuous iliac artery were selected. Severe aortoiliac tortuosity was defined as having either aortoiliac or common iliac angulation <90 degrees. RESULTS: A total of 469 patients between 2008 and 2014 underwent EVAR using the Endurant endograft (Medtronic Cardiovascular, Santa Rosa, Calif). Severe aortoiliac tortuosity was observed in 36% of patients; 17 patients were found to have the main body placed on the side of severe tortuosity without an extension limb. There was a significant shortening of the main body endograft length from 169 mm before EVAR to 147 mm after EVAR (P < .001). The treatment length of the main body, measured from the lowest renal artery to hypogastric artery, also significantly shortened from 179 mm to 170 mm (P < .001). There was a decrease in tortuosity at the most angulated portion of the aneurysm after EVAR, in which angulation changed from 86 degrees to 114 degrees (P < .001). There was no significant change in treatment length (P = .859) and angulation (P = .195) on the nontortuous side of the aneurysm. CONCLUSIONS: The study observed significant shortening of endografts and native aorta and iliac arteries in patients with severe aortoiliac tortuosity during EVAR. This shortening effect can have a negative impact on the distal sealing zone during EVAR. A longer main body or an extension limb should be considered when one is faced with severely tortuous aneurysms.

Patency of the contralateral internal iliac artery in aortouni-iliac endografting.

OBJECTIVE: This study determined the outcome of the contralateral internal iliac artery (IIA) in patients undergoing aortouni-iliac (AUI) endovascular abdominal aortic aneurysm repair (EVAR) with a femorofemoral bypass. METHODS: This retrospective study evaluated 131 consecutive patients undergoing AUI EVAR with femorofemoral bypass at the McGill University Health Center from October 2001 to November 2010. One hundred patients with preoperatively patent contralateral IIA met inclusion criteria for the study. Preoperative demographics and preoperative and postoperative contrast-enhanced computed tomography (CT) scans with multiplanar reconstruction were reviewed for all patients. The last available postoperative CT imaging for all patients was identified and evaluated for contralateral IIA patency. Patency in preoperative and postoperative CT scans was defined as contrast enhancement of the IIA in continuity with the external iliac artery and absence of >50% stenosis at the origin of the IIA. Clinical outcome focused on postoperative pelvic ischemia and reported symptoms of buttock claudication. RESULTS: Mean age at the time of operation was 77.6 ± 6.7 years, and 78% were male. Mean clinical follow-up was 29.2 months after surgery, and mean follow-up of imaging with intravenous contrast was 30.6 months. The last imaging follow-up showed 67 patients (67%) had a patent contralateral IIA and that the IIAs in 33 patients (33%) were occluded (25 [76%]) or stenotic (8 [24%]). Of the patients with IIA occlusion, 80% (20 of 25) were occluded on the first postoperative imaging (median, 8.5 days). Buttock claudication was reported in 18% (6 of 33 patients) with an occluded IIA compared with only 3% (2 of 67 patients) of patients with a patent contralateral IIA on final imaging follow-up (18% vs 3%; P = .014). There were no observed cases of buttock necrosis, spinal ischemia, or colonic ischemia. CONCLUSIONS: Our findings suggest that AUI EVAR with femorofemoral bypass is associated with a significant incidence of contralateral IIA malperfusion on postoperative CT imaging. Occlusion appears to occur early in the postoperative period in most patients, and patient-reported buttock claudication is observed significantly more frequently in patients with an occluded IIA compared with those with a patent IIA. More serious pelvic ischemic complications were not seen in this series. Further study is required to determine whether modification of the procedure can prevent contralateral IIA occlusion and the development of buttock claudication.

A National Survey on Teaching and Assessing Technical Proficiency in Vascular Surgery in Canada.

BACKGROUND: This survey aims to explore trainees' perspectives on how Canadian vascular surgery training programs are using simulation in teaching and assessing technical skills through a cross-sectional national survey. METHODS: A 10-min online questionnaire was sent to Program Directors of Canada's Royal College of Physicians and Surgeons' of Canada approved training programs in vascular surgery. This survey was distributed among residents and fellows who were studying in the 2013-2014 academic year. RESULTS: Twenty-eight (58%) of the 48 Canadian vascular surgery trainees completed the survey. A total of 68% of the respondents were part of the 0 + 5 integrated vascular surgery training program. The use of simulation in the assessment of technical skills at the beginning of training was reported by only 3 (11%) respondents, whereas 43% reported that simulation was used in their programs in the assessment of technical skills at some time during their training. Training programs most often provided simulation as a method of teaching and learning endovascular abdominal aortic or thoracic aneurysm repair (64%). Furthermore, 96% of trainees reported the most common resource to learn and enhance technical skills was dialog with vascular surgery staff. CONCLUSIONS: Surveyed vascular surgery trainees in Canada report that simulation is rarely used as a tool to assess baseline technical skills at the beginning of training. Less than half of surveyed trainees in vascular surgery programs in Canada report that simulation is being used for skills acquisition. Currently, in Canadian training programs, simulation is most commonly used to teach endovascular skills.