Cost-effectiveness analysis of endovascular vs surgical arteriovenous fistula creation in the United States.

OBJECTIVE: In the United States, an estimated $2.8 billion annually is spent on vascular access and its complications. Endovascular arteriovenous fistula (endoAVF) creation is a novel, minimally invasive alternative to traditional surgical AV fistula (sAVF) creation in ≤60% of patients. Although cost effective in single-payer systems, the clinical and financial impact of endoAVF in the United States remains uncertain. METHODS: We constructed a decision tree followed by a probabilistic cohort state-transition model to study the cost effectiveness of endoAVF vs sAVF creation. We conducted a systematic review to obtain input parameters including technical success, maturation, patency, and utility values. We derived costs from the Medicare 2022 fee schedule and from the literature. We used a 5-year time horizon, an annual discount rate of 3% for costs and utilities (measured in quality-adjusted life-years [QALYs]), and the common willingness-to-pay threshold of $50,000. One-way and Monte Carlo probabilistic sensitivity analyses were performed varying technical success, patency, reintervention, cost, and utility parameters. RESULTS: In the base-case scenario, endoAVF ($30,129 average per-person costs, 2.19 QALYs gained, 65% patent at 5 years) was not cost effective compared with sAVF ($12.987 average per-person costs, 2.11 QALYs gained, 66% patent at 5 years), generating an incremental cost-effectiveness ratio of $227,504 per QALY gained. In one-way sensitivity analyses, endoAVF becomes cost effective when the initial cost of sAVF creation exceeds endoAVF by ≥$600 (eg, if endoAVF creation costs ≤$3000 relative to the base-case sAVF cost of $3600), the additional QALYs gained from endoAVF exceeds 0.12 QALYs/year (eg, 0.81 QALYs gained/year from endoAVF compared with base-case sAVF 0.69 QALYs/year), the endoAVF maturation rate is >90% (base case 78%), or the sAVF maturation rate is <65% (base case 78%). Probabilistic sensitivity analysis demonstrated that sAVF remained the optimal strategy in 71% of iterations. CONCLUSIONS: EndoAVF is not cost effective compared with sAVF when modeling 5-year outcomes. The main driver of sAVF remaining cost effective is the four times higher up-front cost for endoAVF creation, as well as a relatively low additional increase in quality of life for endoAVF. It will be important to establish how the endoAVF learning curve contributes to upfront costs and, given the annual cost attributed to vascular access nationally, a randomized controlled trial is warranted.

Association between heart failure and arteriovenous access patency in patients with end-stage renal disease on hemodialysis.

BACKGROUND: Heart disease and chronic kidney disease are often comorbid conditions owing to shared risk factors, including diabetes and hypertension. However, the effect of congestive heart failure (CHF) on arteriovenous fistula (AVF) and AV graft (AVG) patency rates is poorly understood. We hypothesize preexisting HF may diminish blood flow to the developing AVF and worsen patency. METHODS: We conducted a single-institution retrospective review of 412 patients with end-stage renal disease who underwent hemodialysis access creation from 2015 to 2021. Patients were stratified based on presence of preexisting CHF, defined as clinical symptoms plus evidence of reduced left ventricular ejection fraction (EF) (<50%) or diastolic dysfunction on preoperative echocardiography. Baseline demographics, preoperative measures of cardiac function, and dialysis access-related surgical history were collected. Kaplan-Meier time-to-event analyses were performed for primary patency, primary-assisted patency, and secondary patency using standard definitions for patency from the literature. We assessed differences in patency for patients with CHF vs patients without CHF, patients with a reduced vs a normal EF, and AVG vs AVF in patients with CHF. RESULTS: We included 204 patients (50%) with preexisting CHF with confirmatory echocardiography. Patients with CHF were more likely to be male and have comorbidities including, diabetes, chronic obstructive pulmonary disease, hypertension, and a history of cerebrovascular accident. The groups were not significantly different in terms of prior fistula history (P = .99), body mass index (P = .74), or type of hemodialysis access created (P = .54). There was no statistically significant difference in primary patency, primary-assisted patency, or secondary patency over time in the CHF vs non-CHF group (log-rank P > .05 for all three patency measures). When stratified by preoperative left ventricular EF, patients with an EF of <50% had lower primary (38% vs 51% at 1 year), primary-assisted (76% vs 82% at 1 year), and secondary patency (86% vs 93% at 1 year) rates than those with a normal EF. Difference reached significance for secondary patency only (log-rank P = .029). AVG patency was compared against AVF patency within the CHF subgroup, with significantly lower primary-assisted (39% vs 87% at 1 year) and secondary (62% vs 95%) patency rates for AVG (P < .0001 for both). CONCLUSIONS: In this 7-year experience of hemodialysis access creation, reduced EF is associated with lower secondary patency. Preoperative CHF (including HF with reduced EF and HF with preserved EF together) is not associated with significant differences in overall hemodialysis access patency rates over time, but patients with CHF who receive AVG have markedly worse patency than those who receive AVF. For patients with end-stage renal disease and CHF, the risks and benefits must be carefully weighed, particularly for those with low EF or lack of a suitable vein for fistula creation.

Utilizing remote access for electronic medical records reduces overall electronic medical record time for vascular surgery residents.

OBJECTIVE: Survey data suggests that surgical residents spend 20% to 30% of training time using the electronic medical record (EMR), raising concerns about burnout and insufficient operative experience. We characterize trainee EMR activity in the vascular surgery service of a quaternary care center to identify modifiable factors associated with high EMR use. METHODS: Resident activity while on the vascular surgery service was queried from the EMR. Weekends and holidays were excluded to focus on typical staffing periods. Variables including daily time spent, post-graduate year (PGY), remote access via mobile device or personal laptop, and patient census including operative caseload were extracted. Univariate analysis was performed with t tests and χ2 tests where appropriate. We then fit a linear mixed-effects model with normalized daily EMR time as the outcome variable, random slopes for resident and patient census, and fixed effects of PGY level, academic year, and fractional time spent using remote access. RESULTS: EMR activity for 53 residents from July 2015 to June 2019 was included. The mean daily EMR usage was 1.6 hours, ranging from 3.6 hours per day in PGY1 residents to 1.1 hours in PGY4 to 5 residents. Across all PGYs, the most time-consuming EMR activities were chart review (43.0%-46.6%) and notes review (22.4%-27.0%). In the linear mixed-effects model, increased patient census was associated with increased daily EMR usage (Coefficient = 0.61, P-value < .001). Resident seniority (Coefficient = -1.2, P-value < .001) and increased remote access (Coefficient = -0.44, P-value < .001) were associated with reduced daily EMR usage. Over the study period, total EMR usage decreased significantly from the 2015/2016 academic year to the 2018/2019 academic year (mean difference, 2.4 hours vs 1.78; P-value < .001). CONCLUSIONS: In an audit of EMR activity logs on a vascular surgery service, mean EMR time was 1.6 hours a day, which is lower than survey estimates. Resident seniority and remote access utilization were associated with reduced time spent on the EMR, independent of patient census. Although increasing EMR accessibility via mobile devices and personal computers have been hypothesized to contribute to poor work-life balance, our study suggests a possible time-saving effect by enabling expedient access for data review, which constitutes the majority of resident EMR activity. Further research in other institutions and specialties is needed for external validation and exploring implications for resident wellness initiatives.

Early findings and strategies for successful implementation of SIMPL workplace-based assessments within vascular surgery residency and fellowship programs.

OBJECTIVE: As medical education systems increasingly move toward competency-based training, it is important to understand the tools available to assess competency and how these tools are utilized. The Society for Improving Medical Professional Learning (SIMPL) offers a smart phone-based assessment system that supports workplace-based assessment of residents' and fellows' operative autonomy, performance, and case complexity. The purpose of this study was to characterize implementation of the SIMPL app within vascular surgery integrated residency (0+5) and fellowship (5+2) training programs. METHODS: SIMPL operative ratings recorded between 2018 and 2022 were collected from all participating vascular surgery training institutions (n = 9 institutions with 5+2 and 0+5 programs; n = 4 institutions with 5+2 program only). The characteristics of programs, trainees, faculty, and SIMPL operative assessments were evaluated using descriptive statistics. RESULTS: Operative assessments were completed for 2457 cases by 85 attendings and 86 trainees, totaling 4615 unique operative assessment ratings. Attendings included dictated feedback in 52% of assessments. Senior-level residents received more assessments than junior-level residents (postgraduate year [PGY]1-3, n = 439; PGY4-5, n = 551). Performance ratings demonstrated increases from junior to senior trainees for both resident and fellow cohorts with "performance-ready" or "exceptional performance" ratings increasing by nearly two-fold for PGY1 to PGY5 residents (28.1% vs 40.6%), and from first- to second-year fellows (PGY6, 46.7%; PGY7, 60.3%). Similar gains in autonomy were demonstrated as trainees progressed through training. Senior residents were more frequently granted autonomy with "supervision only" than junior residents (PGY1, 8.7%; PGY5, 21.6%). "Supervision only" autonomy ratings were granted to 21.8% of graduating fellows. Assessment data included a greater proportion of complex cases for senior compared with junior fellows (PGY6, 20.9% vs PGY7, 26.5%). Program Directors felt that faculty and trainee buy-in were the main barriers to implementation of the SIMPL assessment app. CONCLUSIONS: This is the first description of the SIMPL app as an operative assessment tool within vascular surgery that has been successfully implemented in both residency and fellowship programs. The assessment data demonstrates expected progressive gains in trainees' autonomy and performance, as well as increasing case complexity, across PGY years. Given the selection of SIMPL as the assessment platform for required American Board of Surgery and Vascular Surgery Board Entrustable Professional Activities assessments, understanding facilitators and barriers to implementation of workplace-based assessments using this app is imperative, particularly as we move toward competency-based medical education.

Athletes in medicine: A systematic review of performance of athletes in medicine.

INTRODUCTION: As interest in medicine grows, admissions committees must review an increasingly competitive pool of medical school and residency candidates. Nearly all admissions committees have moved towards a holistic review, which considers an applicant's experiences and attributes in addition to academic metrics. As such, identifying nonacademic predictors of success in medicine is necessary. Parallels between skills necessary to succeed in athletics and in medicine have been drawn, including teamwork, discipline and resiliency. This systematic review synthesises the current literature to evaluate the relationship between participation in athletics and performance in medicine. METHODS: The authors searched five databases to conduct a systematic review following PRISMA guidelines. Included studies assessed medical students, residents or attending physicians in the United States or Canada and used prior athletic participation as a predictor or explanatory variable. The review examined associations between prior athletic participation and outcomes in medical school, residency and/or as an attending physician. RESULTS: Eighteen studies evaluating medical students (78%), residents (28%) or attending physicians (6%) met inclusion criteria for this systematic review. Twelve (67%) studies specifically assessed participants based on skill level, and five (28%) studies specifically assessed participants based on type of athletic participation (team versus individual). Sixteen studies (89%) found that former athletes performed significantly better than their counterparts (p < 0.05). These studies found significant associations between prior athletic participation and better outcomes in multiple performance indicators, including exam scores, faculty ratings, surgical errors and burnout. CONCLUSIONS: Current literature, although limited, suggests that prior participation in athletics may be a predictor of success in medical school and residency. This was demonstrated through objective scoring methods, such as USMLE, and subjective outcomes, such as faculty ratings and burnout. Specifically, multiple studies indicate that former athletes demonstrated increased surgical skill proficiency and decreased burnout as medical students and residents.

Individual and Program-Related Predictors of Academic Vascular Surgery Practice.

BACKGROUND: Several studies have explored factors affecting academic employment in surgical subspecialties; however, vascular surgery has not yet been investigated. We examined which elements of surgical training predict future academic productivity and studied characteristics of NIH-funded vascular surgery attendings. METHODS: With approval from the Association of Program Directors in Vascular Surgery (APDVS), the database of recent vascular surgery fellowship (VSF) and integrated vascular surgery residency (IVSR) graduates was obtained, and public resources (Doximity, Scopus, PubMed, NIH, etc.) were queried for research output during and after training, completion of dedicated research years, individual and program NIH funding, current practice setting, and academic rank. Adjusted multivariate regression analyses were conducted for postgraduate academic productivity. RESULTS: From 2013 to 2017, there were 734 graduates. Six hundred three completed VSF and 131 IVSR; 220 (29%) were female. Academic employment was predicted by MD degree, advanced degree, training at a top NIH-funded program, number publications by end of training, and H-index. Dedicated research time before or during vascular training, advanced degree, or graduating from a top NIH-funded program were predictors of publishing >1 paper/year. Number of publications by end of training and years in practice were predictive of H-index ≥5. VSF versus IVSR pathway did not have an impact on future academic employment, annual publication rate as an attending, or H-index. Characterization of NIH-funded attendings showed that they often completed dedicated research time (72%) and trained at a top NIH-funded program (79%). Mean publications by graduation among this group was 15.82 ± 11.3, and they averaged 4.31 ± 4.2 publications/year as attendings. CONCLUSIONS: Research output during training, advanced degrees, and training at a top NIH-funded program predict an academic vascular surgery career. VSF and IVSR constitute equally valid paths to productive academic careers.

Trends in annual open abdominal aortic surgical volumes for vascular trainees compared with annual national volumes in the endovascular era.

OBJECTIVE: A prior analysis predicted a shortfall in open abdominal aortic repair (OAR) experience for vascular trainees resulting from the rapid adoption, and increased anatomic suitability, of endovascular aortic aneurysm repair (EVAR) technology. We explored how EVAR has transformed contemporary open aortic surgical education for vascular trainees. METHODS: We examined the Accreditation Council for Graduate Medical Education case volumes of open abdominal aortic aneurysm (AAA) repair and reconstruction for aortoiliac occlusive disease via aortoiliac or femoral bypass (AFB) from integrated vascular surgery residents (VSRs) and fellows (VSFs) graduating from 2006 to 2017 and compared them to the national estimates of total OAR (open AAA repair plus AFB) in the Agency for Healthcare Research and Quality National Inpatient Sample using the International Classification of Diseases, 9th and 10th revision, procedural codes. Changes over time were assessed using the χ2 test, Student's t test, and linear regression. RESULTS: During the 12-year study period, the national annual total OAR and open AAA repair estimates had decreased: total OAR by 72.5% (estimate ± standard error: 2006, 24,255 ± 1185; vs 2017, 6690 ± 274; P < .001) and open AAA repair by 84.7% (estimate ± standard error: 2006, 18,619 ± 924; vs 2017, 2850 ± 168; P < .001). The AFB estimates had decreased by 33.0% (P < .001). The percentage of total OAR, open AAA repair, and AFB performed at teaching hospitals had significantly increased, from ∼55% to 80% (P < .001 for all). A 40.9% decrease was found for open AAA repairs performed by graduating VSFs (mean, 18.6 vs 11) but only a 6.9% decrease in total OAR cases (mean, 27.6 vs 25.7) owing to increasing AFB volumes (mean, 9.0 vs 14.7). The VSR graduates had consistently logged an average of ∼10 open AAA repairs, with a 31.0% increase in total OARs (mean, 23.2 vs 30.4), again secondary to increasing AFB volumes (mean, 11.4 vs 17.5). Although an absolute decrease was found in open aortic experience for VSFs, the rate of decline for the total OAR case volumes was not significantly different after VSR programs had been established (P = .40). CONCLUSIONS: As the incidence has decreased nationally, the use of OAR has been shifting toward teaching hospitals. Although open AAA procedures for trainees have been declining with the increased use of EVAR, open aortic reconstruction for aortoiliac occlusive disease has been increasing, playing an important role in ensuring that vascular trainees continue to have satisfactory OAR experience sufficient for meeting minimum graduation requirements. Strategies to maintain and maximize the education and experience from these cases should be the top priority for vascular surgery program directors.

Early Real-World Experience with EndoAnchors by Indication.

BACKGROUND: The Heli-FX EndoAnchor (EA) system is a transmural aortic fixation device with Federal Drug Administration (FDA) approval for treatment of endoleaks, endograft migration, or high-risk seal zones. Published data are primarily from industry-sponsored registries highlighting safety and efficacy. Our objective is to evaluate real-world outcomes of EA usage after FDA approval across a variety of stent grafts and indications at a single institution. METHODS: We retrospectively reviewed our prospectively maintained aneurysm database for patients undergoing endovascular aortic repair (EVAR) with Heli-FX EAs. Technical success was defined as successful EA deployment, while procedural success was defined as absence of endoleak on completion aortogram. Cohorts were divided by indication and outcomes assessed via review of clinical and radiographic data. RESULTS: From 2016 to 2018, 37 patients underwent EA fixation. We divided the cohort by indication: Group A (prior EVAR with endoleak), B (intraoperative type 1A endoleak), C (high-risk seal zone), and D (thoracic EVAR). In Group A (n = 11), all endoleaks were type 1A and a mean of 10 EAs were deployed with 100% technical and 45.4% procedural success. Two perioperative reinterventions were performed (translumbar coil embolization and proximal graft extension with bilateral renal artery stents). At a mean 10.6 months of follow-up, 45.4% of patients had persistent endoleaks, with 100% aortic-related survival. In Group B (n = 10), a mean of 8.7 EAs were used with 100% technical and procedural success. One immediate adverse event occurred (right iliac dissection from wire manipulation, treated with a covered stent). At 13.6-month mean follow-up, there was significant sac regression (mean 9.75 mm) with no type 1A endoleaks. In Group C (n = 10), a mean of 9.5 EAs were deployed with 100% technical and procedural success. At 11.2-month mean follow-up, there were no residual endoleaks and significant sac regression (mean 3.4 mm). Overall survival was 100%. In Group D (n = 6), a mean of 8.3 EAs were used with 83.3% technical and 66.6% procedural success. One immediate adverse event occurred, in which an EA embolized to the left renal artery. At 9.4-month mean follow-up, overall survival was 83.3% with a mean 2.2-mm increase in sac diameter. CONCLUSIONS: Early experience suggests that EAs effectively treat intraoperative type 1A endoleaks and high-risk seal zones, with significant sac regression and no proximal endoleaks on follow-up. In patients treated for prior EVAR with postoperative type 1A endoleaks, fewer than half resolved after EA attempted repair. Further experience and longer term follow-up will be necessary to determine which patients most benefit from postoperative EA fixation.

Utilization of regional versus general anesthesia and its impact on lower extremity bypass outcomes.

OBJECTIVE: Previous studies evaluating general anesthesia (GA) vs regional (epidural/spinal) anesthesia (RA) for infrainguinal bypass have produced conflicting results. The purpose of this study was to analyze the factors associated with contemporary use of RA and to determine whether it is associated with improved outcomes after infrainguinal bypass in patients with critical limb ischemia. METHODS: Using the Vascular Quality Initiative infrainguinal database, a retrospective review identified all critical limb ischemia patients who received an infrainguinal bypass from 2011 through 2016. Patients were then separated by GA or RA. Primary outcomes were perioperative mortality, complications, and length of stay. Predictive factors for RA and perioperative outcomes were analyzed using a mixed-effects model to adjust for center differences. RESULTS: There were 16,052 patients identified to have a lower extremity bypass during this time frame with 572 (3.5%) receiving RA. There was a wide variation in the use of RA, with 31% of participating centers not using it at all. Age (67.2 vs 70.3 years; P < .001), chronic obstructive pulmonary disease (25.7% vs 30.9%; P < .001), and urgency of the operation (75.7% vs 80.4%; P = .01) were found to be independently associated with receiving a regional anesthetic. Univariate and multivariate analysis demonstrated that length of stay (6.8 days vs 5.7 days; P < .01), postoperative congestive heart failure (2.3% vs 1.1%; P = .040), and change in renal function (5.7% vs 2.9%; P = .005) were all significant outcomes in favor of RA. There was a trend toward lower mortality rates; however, this did not reach statistical significance. Rates of myocardial infarction, pulmonary complications, and stroke were not found to be statistically different. Coarsened exact matching continued to demonstrate a difference in length of stay and rates of new-onset congestive heart failure in favor of RA. CONCLUSIONS: RA is an infrequent but effective form of anesthesia for infrainguinal bypass surgery. Elderly patients and those with underlying respiratory problems may benefit from this form of anesthesia. Further evaluation within institutions should be performed to identify which patients would most benefit from RA or GA.

Duplex ultrasound surveillance of renal branch grafts after fenestrated endovascular aneurysm repair.

OBJECTIVE: The use of duplex ultrasound (DUS) examinations for surveillance after fenestrated endovascular aneurysm repair (FEVAR) is not well-studied. Our objective was to further characterize normal and abnormal duplex findings in renal branch grafts after FEVAR. METHODS: We retrospectively reviewed a single-center experience involving consecutive patients treated with Cook ZFEN devices between 2012 and 2017. Postoperative imaging consisted of a computed tomography (CT) scan at 1 month, 6 months, 1 year, and annually thereafter. As experienced progressed, DUS examination with or without concurrent CT scans were obtained in a nonstandardized protocol, particularly for patients with decreased renal function. Renal patency loss was defined as occlusion or stenosis of greater than 50% evaluated on 3-day renal artery center-line imaging. RESULTS: A total of 116 patients were treated with FEVAR, of which 60 (51.7%) had concurrent CT and renal DUS images available for review. Six patients (10%) had limited ultrasound studies owing to bowel gas and were excluded. The study cohort therefore included 54 patients receiving of 94 renal fenestrated stents with a mean follow-up of 23 months. Twelve cases of renal patency loss in 10 patients (9 stenoses, 3 occlusions) were found on CT scanning, 11 (91.6%) of which had concurrent abnormalities found on ultrasound examination. Stents with compression at the junction of the main body exhibited significantly elevated mean Peak systolic velocities (PSV) compared with nonstenosed stents (349.2 cm/s vs 115.3 cm/s; P = .003). Stenosis in the most proximal portion of the stent (ie, within the main body) showed no difference in proximal PSV (86.0 cm/s vs 131.9 cm/s; P = .257); however, dampened PSV showed significant differences in the mid (17.5 cm/s vs 109.9 cm/s; P = .027) and distal (19.0 cm/s vs 78.3 cm/s; P = .028) segments compared with nonstenosed stents. All occluded stents demonstrated no flow detection. Proximal PSV served as a strong classifier for junctional stenosis (area under the curve, 0.98). A combined criterion of proximal PSV of greater than 215 cm/s or distal PSV of less than 25 cm/s resulted in a sensitivity of 91.6% and specificity of 85.3% for detecting patency loss. All stents that were compromised underwent successful secondary reintervention and restoration of patency. CONCLUSIONS: DUS imaging is a clinically useful modality for surveillance of renal branch grafts after FEVAR. Patterns of segmental velocity elevation (proximal PSV, >215 cm/s) and dampening in the distal renal indicate potential hemodynamic compromise and should prompt more aggressive workup or imaging and likely be considered for secondary intervention.

Secondary interventions in patients with implantable cardiac devices and ipsilateral arteriovenous access.

OBJECTIVE: The number of patients with end-stage renal disease who require implantable cardiac devices is increasing. Rates of secondary interventions or fistula failure are not well studied in patients who have arteriovenous fistula (AVF) access placed on the ipsilateral side as a pacemaker. This study aimed to compare central vein-related interventions and failure rates of arteriovenous access in patients with pacemakers placed on the ipsilateral vs contralateral side. METHODS: A retrospective review of a prospectively collected database at a single high-volume dialysis institution was performed; all patients 18 years or older who had both arteriovenous access and a pacemaker were included. Data points included the number of interventions such as thrombectomy, percutaneous transluminal angioplasty, and stent placement, as well as time to first intervention and failure of the fistula or graft. Patients with an implantable cardiac device who had contralateral AVF access were compared with AVF ipsilateral access using a t-test and Kaplan-Meier curves for primary patency. Outcomes evaluated included number of interventions and time to intervention from access creation. RESULTS: A total of 32 patients were identified; 20 had arteriovenous access on the contralateral side from the pacemaker and 12 had access on the ipsilateral side. In the contralateral group, there were a mean of 3.6 percutaneous transluminal angioplasties per patient (range, 1-12). In the ipsilateral group, there were an average of 2.8 percutaneous transluminal angioplasties per patient (range, 1-6). There was no difference in intervention rates between these cohorts; however, the time to intervention was increased in patients who had arteriovenous access on the contralateral side to their pacemaker (9.5 vs 19.5 months; P < .05). Patency rates did not differ (P = .068). CONCLUSIONS: There was no difference in intervention rates between ipsilateral and contralateral patients; however, the time to intervention was increased in patients who had arteriovenous access on the contralateral side to their pacemaker (9.5 months vs 19.5 months). This study was limited by its lack of power. Patency rates did not differ (P = .068). Ipsilateral access placement should be considered rather than abandoning access in that extremity.

Complex endovascular aneurysm repair is associated with higher perioperative mortality but not late mortality compared with infrarenal endovascular aneurysm repair among octogenarians.

OBJECTIVE: As our collective experience with complex endovascular aneurysm repair (EVAR) has grown, an increasing number of older patients are being offered endovascular repair of juxtarenal aneurysms. Outcomes after complex EVAR in this older subpopulation are not well-described. We sought to specifically evaluate clinical outcomes after complex EVAR compared with infrarenal EVAR in a cohort of octogenarians. METHODS: A single-center retrospective review was conducted using a database of consecutive patients treated with elective EVAR for abdominal aortic aneurysms (AAAs) between 2009 and 2015. Only patients 80 years of age or older were included. Patients in the complex EVAR group were treated with either snorkel/chimney or fenestrated techniques, whereas infrarenal EVAR consisted of aneurysm repair without renal or visceral involvement. Relevant demographic, anatomic, and device variables, and clinical outcomes were collected. RESULTS: There were 103 patients (68 infrarenal, 35 complex) treated within the study period with a mean follow-up of 21 months. A total of 75 branch grafts were placed (59 renal, 11 celiac, 5 superior mesenteric artery) in the complex group, with a target vessel patency of 98.2% at latest follow-up. Patients undergoing complex EVAR were more likely to be male (82.8% vs 60.2%; P = .02) and have a higher prevalence of renal insufficiency (71.4% vs 44.2%; P = .008). The 30-day mortality was significantly greater in patients treated with complex EVAR (8.6% vs 0%; P = .03). There were no differences in major adverse events (P = .795) or late reintervention (P = .232) between groups. Interestingly, sac growth of more than 10 mm was noted to be more frequent with infrarenal EVAR (17.6% vs 2.8%; P = .039). However, both type IA (5.7% infrarenal; 4.9% complex) and type II endoleaks (32.3% infrarenal; 25.7% complex) were found to be equally common in both groups. Complex EVAR was not associated with increased all-cause mortality at latest follow-up (P = .322). Multivariable Cox modeling demonstrated that AAAs greater than 75 mm in diameter (hazard ratio; 4.9; 95% confidence interval, 4.6-48.2) and renal insufficiency (hazard ratio, 3.71; 95% confidence interval, 1.17-11.6) were the only independent risk factors of late death. CONCLUSIONS: Complex EVAR is associated with greater perioperative mortality compared with infrarenal EVAR among octogenarians. However, late outcomes, including the need for reintervention and all-cause mortality, are not significantly different. Larger aneurysms and chronic kidney disease portends greater risk of late death after EVAR, regardless of AAA complexity. These patient-related factors should be considered when offering endovascular treatment to older patients.

Infrarenal endovascular aneurysm repair with large device (34- to 36-mm) diameters is associated with higher risk of proximal fixation failure.

OBJECTIVE: Endovascular aneurysm repair (EVAR) has become the standard of care for infrarenal aneurysms. Endografts are commercially available in proximal diameters up to 36 mm, allowing proximal seal in necks up to 32 mm. We sought to further investigate clinical outcomes after standard EVAR in patients requiring large main body devices. METHODS: We performed a retrospective review of a prospectively maintained database for all patients undergoing elective EVAR for infrarenal abdominal aortic aneurysms at a single institution from 2000 to 2016. Only endografts with the option of a 34- to 36-mm proximal diameter were included. Requisite patient demographics, anatomic and device-related variables, and relevant clinical outcomes and imaging were reviewed. The primary outcome in this study was proximal fixation failure, which was a composite of type IA endoleak and stent graft migration >10 mm after EVAR. Outcomes were stratified by device diameter for the large-diameter device cohort (34-36 mm) and the normal-diameter device cohort (<34 mm). RESULTS: There were 500 patients treated with EVAR who met the inclusion criteria. A total of 108 (21.6%) patients received large-diameter devices. There was no difference between the large-diameter cohort and the normal-diameter cohort in terms of 30-day (0.9% vs 0.95%; P = .960) or 1-year mortality (9.0% vs 6.2%; P = .920). Proximal fixation failure occurred in 24 of 392 (6.1%) patients in the normal-diameter cohort and 26 of 108 (24%) patients in the large-diameter cohort (P < .001). There were 13 (3.3%) type IA endoleaks in the normal-diameter cohort and 16 (14.8%) in the large-diameter cohort (P < .001). Stent graft migration (>10 mm) occurred in 15 (3.8%) in the normal-diameter cohort and 16 (14.8%) in the large-diameter cohort (P < .001). After multivariate analysis, only the use of Talent (Medtronic, Minneapolis, Minn) endografts (odds ratio [OR], 4.50; 95% confidence interval [CI], 1.18-17.21) and neck diameter ≥29 mm (OR, 2.50; 95% CI, 1.12-5.08) remained significant independent risk factors for development of proximal fixation failure (OR, 3.99; 95% CI, 1.75-9.11). CONCLUSIONS: Standard EVAR in patients with large infrarenal necks ≥29 mm requiring a 34- to 36-mm-diameter endograft is independently associated with an increased rate of proximal fixation failure. This group of patients should be considered for more proximal seal strategies with fenestrated or branched devices vs open repair. Also, this group likely needs more stringent radiographic follow-up.

Arteriovenous Fistula and Graft Construction in Patients with Implantable Cardiac Devices: Does Side Matter?

BACKGROUND: Limited reports have documented the effect cardiac implantable electronic devices (CIEDs) have on arteriovenous (AV) access patency. Current recommendations suggest placing the access on the contralateral side of the CIEDs, as there is concern for increased central venous stenosis and access failure. The goal of this study is to review our single-center AV access patency rates for dialysis patients with an ipsilateral or contralateral side CIED. METHODS: A retrospective review was performed from 2008 to 2016 at a single institution identifying all patients who have received a CIED and the diagnosis of end-stage renal disease (ESRD). Medical records were queried to identify each patient's dialysis access and whether it was ipsilateral or contralateral to the CIED. Primary outcomes of study were primary and secondary patency rates. RESULTS: A total of 44 patients were identified to have ESRD and CIED. Of these patients, 28 patients with fistulas or grafts (13 ipsilateral and 15 contralateral) had follow-up with regards to their AV access. There were 3 primary failures in both groups. For patients who had the CIED placed after already starting the dialysis, patency was based on when the cardiac device was implanted. Primary patency for ipsilateral and contralateral access was 20.2 and 22.2 months, respectively. With secondary interventions, ipsilateral and contralateral mean patency was 39 and 48.8 months, respectively. Six-month and 1-year primary patency for arteriovenous fistula or arteriovenous graft on patients with ipsilateral access was 69.2% and 53.8%, respectively. Ipsilateral 1-year cumulative patency was 39 months. CONCLUSIONS: CIED may lead to stenosis or occlusion to one's AV access; however, primary assisted and secondary patency rates are still acceptable at 6 months and 1 year compared to Kidney Disease Outcomes Quality Initiative guidelines. Despite a CIED, a surgeon's algorithm should not lead to the abandonment of an ipsilateral access if the central venous system is patent.

Outcomes of open and endovascular lower extremity revascularization in active smokers with advanced peripheral arterial disease.

OBJECTIVE: Concern over perioperative and long-term durability of lower extremity revascularizations among active smokers is a frequent deterrent for vascular surgeons to perform elective lower extremity revascularization. In this study, we examined perioperative outcomes of lower extremity endovascular (LEE) revascularization and open lower extremity bypass (LEB) in active smokers with intermittent claudication (IC) and critical limb ischemia (CLI). METHODS: Active smokers undergoing LEE or LEB from 2011 to 2014 were identified in the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) targeted vascular data set. Patient demographics, comorbidities, anatomic features, and perioperative outcomes were compared between LEE and LEB procedures. Subgroup analysis was performed for patients undergoing revascularization for IC and CLI independently. RESULTS: From 2011 to 2014, 4706 lower extremity revascularizations were performed in active smokers (37% of all revascularizations). In this group, 1497 were LEE (55.6% for CLI, 13.4% for below-knee pathology) and 3209 were LEB (68.9% CLI, 34.7% below-knee). Patients undergoing LEE had higher rates of female gender, hypertension, end-stage renal disease, and diabetes (all P ≤ .02). LEE patients also had a higher frequency of prior percutaneous interventions (22.7% vs 17.2%; P < .01) and preoperative antiplatelet therapy (82.3% vs 78.7%; P = .02). On risk-adjusted multivariate analysis, LEE patients had higher need for reintervention on the treated arterial segment than LEB (5.1% vs 5.2%; odds ratio [OR], 1.52; 95% confidence interval [CI], 1.08-2.13; P = .02) but had lower wound complications (3.1% vs 13.2%; OR, 0.32; 95% CI, 0.23-0.45; P < .01) and no statistically significant difference in 30-day mortality (0.6% vs 0.9%), myocardial infarction or stroke (1.1% vs 2.6%), or major amputation (3.2% vs 2.1%) in the overall cohort of active smokers. In the IC subgroup, myocardial infarction or stroke was significantly higher in the LEB group (1.9% vs 0.6%; OR, 1.83; 95% CI, 1.17-1.97; P = .03), although no difference was found in the CLI subgroup (2.8% vs 1.4%; OR, 0.75; 95% CI, 0.37-1.52; P = .42,). Also in IC group, there was a trend for lower major amputation rates ≤30 days in the LEE group, whereas in the CLI group, LEE had a trend toward higher risk of early amputation compared with LEB. CONCLUSIONS: In active smokers, LEB for IC and CLI requires fewer reinterventions but is associated with a higher rate of postoperative wound complications compared with LEE revascularization. However, the risk for limb amputation is higher in actively smoking patients when treated by LEE compared with LEB for CLI. Importantly, cardiovascular complications are significantly higher in actively smoking patients with IC undergoing LEB compared with LEE. This additional cardiovascular risk should be carefully weighed when proposing LEB for actively smoking patients with nonlimb-threatening IC.

Influence of gender and use of regional anesthesia on carotid endarterectomy outcomes.

OBJECTIVE: Carotid endarterectomy (CEA) is the most commonly performed surgical procedure to reduce the risk of stroke. The operation may be performed under general anesthesia (GA) or regional anesthesia (RA). We used a national database to determine how postoperative outcomes were influenced by gender and type of anesthesia used. METHODS: All patients who underwent CEA between 2005 and 2011 were identified from the American College of Surgeons National Surgical Quality Improvement Program database (N = 41,442). Incidence of stroke and myocardial infarction (MI) within 30 days as well as other postoperative complications, operative time, and hospital length of stay were examined in groups separated by gender and anesthesia type. Multivariable logistic regression with effect modification was used to determine significant risk-adjusted differences between genders and type of anesthesia to assess outcomes after CEA. RESULTS: The male-to-female ratio among CEA cases performed was approximately 3:2. Most cases were performed under GA (85% male patients, 86% female patients). Adjusted multivariable analysis showed no statistical difference in rates of MI and stroke based on gender or type of anesthesia used. There were, however, higher 30-day postoperative local complications and MI (both P < .05) in those who had GA vs RA regardless of gender before adjustment. Total operative time was decreased (mean difference, -8.15 minutes; 95% confidence interval, -10.09 to -6.21; P < .001) and length of stay was increased (mean difference, 0.34 day; 95% confidence interval, 0.14-0.54; P < .02) in women, with statistical significance, whether RA or GA was used. CONCLUSIONS: On adjusted multivariate analysis, there is no statistically significant difference in postoperative incidence of MI or stroke between men and women undergoing CEA. Use of RA vs GA did not affect this finding. Furthermore, there was no correlation between gender and the type of anesthesia chosen. Women, however, experienced decreased operative times and increased length of stay regardless of anesthesia type.

Risk factors and outcomes of postoperative ischemic colitis in contemporary open and endovascular abdominal aortic aneurysm repair.

OBJECTIVE: Postoperative ischemic colitis (IC) can be a serious complication following infrarenal abdominal aortic aneurysm (AAA) repair. We sought to identify risk factors and outcomes in patients developing IC after open AAA repair and endovascular aneurysm repair (EVAR). METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was used to examine clinical data of patients undergoing AAA repair from 2011 to 2012 who developed postoperative IC. Multivariate regression analysis was performed to identify risk factors and outcomes. RESULTS: We evaluated a cohort of 3486 patients who underwent AAA repair (11.6% open repair and 88.4% EVAR). The incidence of postoperative IC was 2.2% (5.2% for open repair and 1.8% for EVAR). Surgical treatment was needed in 49.3% of patients who developed IC. The mortality of patients with IC was higher than that of patients without IC (adjusted odds ratio [AOR], 4.23; 95% confidence interval [CI], 2.26-7.92; P < .01). The need for surgical treatment (AOR, 7.77; 95% CI, 2.08-28.98; P < .01) and age (AOR, 1.11; 95% CI, 1.01-1.22; P = .01) were mortality predictors of IC patients. Predictive factors of IC included need for intraoperative or postoperative transfusion (AOR, 6; 95% CI, 3.08-11.72; P < .01), rupture of the aneurysm before surgery (AOR, 4.07; 95% CI, 1.78-9.31; P < .01), renal failure requiring dialysis (AOR, 3.86; 95% CI, 1.18-12.62; P = .02), proximal extension of the aneurysm (AOR, 2.19; 95% CI, 1.04-4.59; P = .03), diabetes (AOR, 1.87; 95% CI, 1.01-3.46; P = .04), and female gender (AOR, 1.75; 95% CI, 1.01-3.02; P = .04). Although open AAA repair had three times higher rate of postoperative IC compared with endovascular repair, in multivariate analysis we did not find any statistically significant difference between open repair and EVAR in the development of IC (5.2% vs 1.8%; AOR, 1.25; 95% CI, 0.70-2.25; P = .43). CONCLUSIONS: Postoperative IC has a rate of 2.2% after AAA repair. However, it is associated with 38.7% mortality rate. Rupture of the aneurysm before surgery, need for transfusion, proximal extension of the aneurysm, renal failure requiring dialysis, diabetes, and female gender were significant predictors of postoperative IC. AAA patients who develop IC have four times higher mortality compared with those without IC. Surgical treatment is needed in nearly 50% of IC patients and is a predictor of higher mortality.

Development and evaluation of a retroperitoneal dialysis porcine model.

OBJECTIVES: We attempted to create a surgical model to evaluate the retroperitoneal space for the ability to transfer solutes through the retroperitoneal membrane. Our dual objectives were to develop a technique to assess the feasibility of retroperitoneal dialysis (RPD) in a porcine model. METHODS: We incorporated two 35-kg Yorkshire pigs for this pilot study. In the first animal, we clamped renal vessels laparoscopically. In the second animal, we embolized renal arteries. In both animals, we dilated the retroperitoneal space bilaterally and deployed dialysis catheters. We measured serum creatinine (Cr), urea, and electrolytes at baseline 6 hours before the dialysis and every 4 hours after. RESULTS: We successfully created retroperitoneal spaces bilaterally and deployed dialysis catheters in both animals. In the first animal, dialysate and plasma Cr ratio (D/P) on the left and right side were 0.43 and 0.3, respectively. Cr clearance by 40 minutes of dialysis treatment was 6.3 mL/min. The ratio of dialysate glucose at 4 hours dwell time to dialysate glucose at 0 dwell time (D/D0) for left/rights sides were 0.02 and 0.02, respectively. kt/Vurea was 0.43. In the second animal, D/P Cr for left/right sides were 0.34 and 0.33, respectively. kt/Vurea was 0.17. We euthanized the pigs due to fluid collection in the peritoneal space and rapid increase of serum Cr, urea, and electrolytes. CONCLUSIONS: We demonstrated the feasibility of creation of a functionally anephric porcine model with successful development of retroperitoneal spaces using balloon inflation. Notwithstanding minimal clearance and limited diffusion capacity in this experiment, additional studies are needed to examine potential use of retroperitoneal space for peritoneal dialysis.

Experience matters more than specialty for carotid stenting outcomes.

OBJECTIVE: The introduction of carotid stenting has led to a rapid rise in the number of vascular specialists performing this procedure. The Carotid Revascularization Endarterectomy vs Stenting Trial (CREST) has shown that carotid stenting can be performed with an equivalent major event rate compared with carotid endarterectomy. However, there is still controversy about the appropriate training and experience required to safely perform this procedure. This observational study examined the performance of carotid stenting with regard to specialty and case volume. METHODS: From 2004 to 2011, inpatients diagnosed with carotid stenosis who had a carotid stenting procedure were extracted from the Nationwide Inpatient Sample database. The cohort was separated on the basis of the provider performing the procedure (surgeon vs interventionalist), hospital location, and volume. Surgeons were defined as providers who also performed either a carotid endarterectomy or femoral-popliteal bypass during the same time interval. Primary end points analyzed included stroke, myocardial infarction, and 30-day mortality. Length of stay and hospital costs were also analyzed as secondary outcomes. RESULTS: A total of 20,663 cases of carotid stenting were found; 15,305 (74%) cases were identified to be performed by a "surgeon," whereas 5358 (26%) were done by an "interventionalist." The majority of cases were done at hospitals in urban locations (96.51%) and designated teaching institutions (61.47%). Unadjusted outcomes were similar between surgeons and interventionalists in terms of stroke (4.33% and 4.41%), myocardial infarction (2.10% and 2.13%), and mortality (0.84% and 1.03%) respectively. Qualitatively, volume per 10 cases was shown to decrease the risk of stroke. Adjusted multivariate analysis demonstrated no statistical significance between primary end point outcomes. However, length of stay (2.81 vs 3.08 days) and total charges ($48,087.61 and $51,718.77) were lower for procedures performed by surgeons. CONCLUSIONS: Surgeons are performing the majority of carotid stent procedures in the United States. The volume of cases performed by a provider, rather than the provider's specialty, appears to be a stronger predictor of adverse outcomes for carotid stenting. There were, however, significant cost differences between surgeons and interventionalists, which needs to be further evaluated at an institutional level.