Evolution of fenestrated/branched endovascular aortic aneurysm repair complexity and outcomes at an organized center for the treatment of complex aortic disease.

BACKGROUND: Fenestrated/branched endovascular aneurysm repair (F/BEVAR) volume has increased rapidly, with favorable outcomes at centers of excellence. We evaluated changes over time in F/BEVAR complexity and associated outcomes at a single-center complex aortic disease program. METHODS: Prospectively collected data of all F/BEVAR (definition: requiring ≥1 fenestration/branch), procedures performed in an institutional review board-approved registry and/or physician-sponsored investigational device exemption trial (IDE# G130210), were reviewed (11/2010-2/2019). Patients were stratified by surgery date into thirds: early experience, mid experience, and recent experience. Patient and operative characteristics, aneurysm morphology, device types, perioperative and midterm outcomes (survival, freedom from type I or III endoleak, target artery patency, freedom from reintervention), were compared across groups. RESULTS: For 252 consecutive F/BEVARs (early experience, n = 84, mid experience, n = 84, recent experience, n = 84), 194 (77%) company-manufactured custom-made devices, 11 (4.4%) company-manufactured off-the-shelf devices, and 47 (19%) physician-modified devices, were used to treat 5 (2.0%) common iliac, 97 (39%) juxtarenal, 31 (12%) pararenal, 116 (46%) thoracoabdominal, and 2 (0.8%) arch aneurysms. All patients had follow-up for 30-day events. The mean follow-up time for the entire cohort was 589 days (interquartile range, 149-813 days). On 1-year Kaplan-Meier analysis, survival was 88%, freedom from type I or III endoleak was 91%, and target vessel patency was 92%. When stratified by time period, significant differences included aneurysm extent (thoracoabdominal, 33% early experience, 40% mid experience, and 64% recent experience; P < .001) and target vessels per case (four-vessel case, 31% early experience, 39% mid experience, and 67% recent experience; P < .0001). There was no difference, but a trend toward improvement, in composite 30-day events (early experience, 39%; mid experience, 23%; recent experience, 27%; P = .05). On Kaplan-Meier analysis, there was no difference in survival (P = .19) or target artery patency (P = .6). There were differences in freedom from reintervention (P < .01) and from type I or III endoleak (P = .02), with more reinterventions in the early experience, and more endoleaks in the recent period. CONCLUSIONS: Despite increasing repair complexity, there has been no significant change in perioperative complications, overall survival, or target artery patency, with favorable outcomes overall. Type I or III endoleaks remain a significant limitation, with increased incidence as the number of branch arteries incorporated into the repairs has increased.

Impact of acute kidney injury on long-term outcomes after fenestrated and branched endovascular aortic aneurysm repair.

OBJECTIVE: Acute kidney injury (AKI) has been identified as a common complication after fenestrated and branched endovascular aneurysm repair (F/BEVAR), occurring in 5% to 29% of patients. Predictors of AKI and its impact on long-term outcomes remain unknown. We sought to identify independent predictors of AKI and its effect on long-term survival after F/BEVAR. METHODS: A single-institution retrospective review of all consecutive F/BEVAR procedures was performed (November 2010-September 2018). Data were collected prospectively through an Institutional Review Board-approved registry and a physician-sponsored investigational device exemption clinical trial (G130210). AKI was defined as a decrease in estimated glomerular filtration rate by >30% from baseline, within 30 days postoperatively. The cohort was stratified according to whether a patient experienced AKI. Demographics, operative details, perioperative complications, and length of stay between groups were compared. The primary outcome, long-term survival, was assessed with Kaplan-Meier analysis and Cox proportional hazards modeling. Independent predictors of AKI were identified using logistic regression. RESULTS: Among 219 consecutive F/BEVAR patients, AKI occurred in 41 patients (19%) and was the most common 30-day complication observed. Whereas preoperative creatinine concentration, estimated glomerular filtration rate, and target renal artery stenosis >50% did not predict AKI, the occurrence of intraoperative complications did correlate with AKI (37% vs 7.3%; P < .01). By 30 days, AKI resolved in 7 (17%) patients, persisted without need for dialysis in 26 (64%), and progressed to dialysis in 5 (12%); the remaining 3 (7%) patients died. Survival at 30 days was significantly lower in the AKI group (92.7% vs 98.9%; P = .047), and this difference persisted at 1 year (68% vs 87%; log-rank, P <.01) and 3 years (44% vs 60%; log-rank, P = .04). On multivariable modeling, AKI increased the hazard of death nearly twofold (hazard ratio, 1.92; 95% confidence interval [CI], 1.11-3.23; P = .019). Independent predictors of AKI on multivariable logistic regression were intraoperative complications (odds ratio, 4.10; 95% CI, 1.61-10.42; P < .01) and increased operating room time (odds ratio, 1.56; 95% CI, 1.22-2.00; P < .01). CONCLUSIONS: In our 8-year experience of F/BEVAR, AKI was the most common postoperative complication observed in nearly 20% of patients. AKI after F/BEVAR is associated with decreased short- and long-term survival. Whether AKI is causative or just associated with decreased survival remains to be elucidated. Further study is needed to determine whether the independent predictors of AKI, including intraoperative complications and operating room time, are generalizable across all centers performing F/BEVAR and to investigate how we might further mitigate this common and serious complication.

Acute Limb Ischemia in a 26-Year-Old Man Presenting with an Idiopathic Thrombosed Popliteal Artery Aneurysm.

Popliteal artery aneurysms (PAAs) are the most common peripheral arterial aneurysms and develop almost exclusively (>90%) in men who have a history of tobacco abuse at an average age of 65 years. Most PAAs are caused by chronic inflammation secondary to atherosclerotic disease; other nondegenerative causes of PAAs include arterial trauma, infection, Behçet's disease, medial fibromuscular dysplasia, or popliteal artery entrapment. Few case reports have been published on idiopathic congenital PAAs. We report a case of a 26-year-old man who presented with progressive claudication and subsequent acute limb ischemia due to the thrombosis of a large idiopathic PAA. Our case demonstrates that the differential diagnosis of young adult or pediatric patients presenting with signs of acute limb ischemia or claudication should include a symptomatic PAA.

Type 2 diabetes impairs the ability of skeletal muscle pericytes to augment postischemic neovascularization in db/db mice.

Peripheral artery disease is an atherosclerotic occlusive disease that causes limb ischemia and has few effective noninterventional treatments. Stem cell therapy is promising, but concomitant diabetes may limit its effectiveness. We evaluated the therapeutic potential of skeletal muscle pericytes to augment postischemic neovascularization in wild-type and type 2 diabetic (T2DM) mice. Wild-type C57BL/6J and leptin receptor spontaneous mutation db/db T2DM mice underwent unilateral femoral artery excision to induce limb ischemia. Twenty-four hours after ischemia induction, CD45-CD34-CD146+ skeletal muscle pericytes or vehicle controls were transplanted into ischemic hindlimb muscles. At postoperative day 28, pericyte transplantation augmented blood flow recovery in wild-type mice (79.3 ± 5% vs. 61.9 ± 5%; P = 0.04), but not in T2DM mice (48.6% vs. 46.3 ± 5%; P = 0.51). Pericyte transplantation augmented collateral artery enlargement in wild-type (26.7 ± 2 µm vs. 22.3 ± 1 µm, P = 0.03), but not T2DM mice (20.4 ± 1.4 µm vs. 18.5 ± 1.2 µm, P = 0.14). Pericyte incorporation into collateral arteries was higher in wild-type than in T2DM mice ( P = 0.002). Unexpectedly, pericytes differentiated into Schwann cells in vivo. In vitro, Insulin increased Nox2 expression and decreased tubular formation capacity in human pericytes. These insulin-induced effects were reversed by N-acetylcysteine antioxidant treatment. In conclusion, T2DM impairs the ability of pericytes to augment neovascularization via decreased collateral artery enlargement and impaired engraftment into collateral arteries, potentially via hyperinsulinemia-induced oxidant stress. While pericytes show promise as a unique form of stem cell therapy to increase postischemic neovascularization, characterizing the molecular mechanisms by which T2DM impairs their function is essential to achieve their therapeutic potential.

Fenestrated endovascular aortic aneurysm repair using physician-modified endovascular grafts versus company-manufactured devices.

OBJECTIVE: Fenestrated endografts are customized, patient-specific endovascular devices with potential to reduce morbidity and mortality of complex aortic aneurysm repair. With approval from the U.S. Food and Drug Administration, our center began performing fenestrated endovascular aneurysm repair through a physician-sponsored investigational device exemption (IDE #G130210), using both physician-modified endografts (PMEGs) and company-manufactured devices (CMDs). Because these techniques are associated with specific advantages and disadvantages, we sought to investigate differences in outcomes between PMEG and CMD cases. METHODS: A single-institution retrospective review of all fenestrated endovascular aneurysm repairs was performed. The cohort was analyzed by device type (PMEG or CMD) after matching of cases on the basis of (1) number of target vessels intended for treatment, (2) extent of aneurysm, (3) aneurysm diameter, (4) device configuration, and (5) date of operation. Outcomes of ruptures, common iliac artery aneurysms, and aortic arch aneurysms were excluded. Demographics, operative details, perioperative complications, length of stay, and reinterventions were compared. For patients with >1 year of follow-up time, survival, type I or type III endoleak rate, target artery patency, and reintervention rate were estimated using the Kaplan-Meier method. RESULTS: Between November 30, 2010, and July 30, 2016, 82 patients were identified and matched. The cohort included 41 PMEG and 41 CMD patients who underwent repair of 38 juxtarenal (PMEG, 17; CMD, 21; P = .38), 14 pararenal (PMEG, 6; CMD, 8; P = .56), and 30 thoracoabdominal type I to type IV (PMEG, 18; CMD, 12; P = .17) aneurysms. There were significant differences in presentation requiring urgent aneurysm repair (PMEG, 9; CMD, 0; P = .002), total fluoroscopy time (PMEG, 76 minutes; CMD, 61 minutes; P = .02), volume of contrast material used (PMEG, 88 mL; CMD, 70 mL; P = .02), in-operating room to out-of-operating room time (PMEG, 391 minutes; CMD, 319 minutes; P = .001), incision to surgery end time (PMEG, 276 minutes; CMD, 224 minutes; P = .002), and 1-year reintervention rate (PMEG, 37%; CMD, 13%; log-rank P = .04). No differences in perioperative complications, overall length of stay, type I or type III endoleak, or survival were observed between PMEG and CMD. For the entire cohort including both PMEG and CMD, the overall rate of any 30-day postoperative complication was 39%, and the Kaplan-Meier estimate of survival at 1 year was 86%. CONCLUSIONS: In this single-institution experience of fenestrated endovascular aneurysm repair, the primary differences between PMEG and CMD related only to operative metrics and the need for postoperative reinterventions. No statistically significant advantage was found for one approach over the other; we therefore cannot conclude that one approach is better than the other. Both remain viable options that may compare favorably with open repair of complex aortic aneurysms. Further studies are necessary to determine whether this relative equivalence represents a type II error or lack of long-term durability data or whether true equivalence between PMEG and CMD approaches exists.

Reinterventions after fenestrated or branched endovascular aortic aneurysm repair.

OBJECTIVE: Reinterventions after fenestrated or branched endovascular aneurysm repair (F/B-EVAR) are sometimes necessary to maintain aneurysm exclusion or endograft and target artery patency. These reinterventions are nontrivial, potentially associated with morbidity, mortality, and resource utilization. Whereas rates, types, and outcomes of reintervention after infrarenal EVAR have been well described, they have not been well described for F/B-EVAR. We sought to characterize the morbidity, mortality, and resource utilization due to reinterventions after F/B-EVAR. METHODS: All F/B-EVAR variables collected prospectively through a single-institution, Institutional Review Board-approved registry, which included patients enrolled in a physician-sponsored investigational device exemption trial (G130210), were reviewed (November 2010-December 2016). Reinterventions were defined as any procedure that was aneurysm related, device related, or target artery related. For patients with more than one reintervention, each intervention occurrence was treated as a discrete event. Reintervention type, indication, timing (perioperative, days 0-30; short term, days 31-180; midterm, >180 days), inpatient/outpatient, length of stay, and morbidity/mortality were recorded. Reintervention success was defined as resolution of the indication. RESULTS: Among 123 consecutive F/B-EVARs (mean follow-up, 25 months), 32 patients (25%) underwent 54 reinterventions (one reintervention, 20 (63%) patients; two reinterventions, 6 (19%) patients; three reinterventions, 4 (13%) patients; four reinterventions, 1 (3.1%) patient; and six reinterventions, 1 (3.1%) patient). The most frequent indications were type III endoleaks (n = 15 [28%]), target artery occlusions (n = 7 [13%]), and stenoses (n = 6 [11%]). These were performed in the perioperative, short-term, and midterm time frames 17%, 41%, and 43% of the time, respectively. Reinterventions were percutaneous (67%), inpatient procedures (61%), with median length of stay of 5 days. Of the 32 reintervention patients, 4 experienced access site complications and 4 died <30 days after reintervention (3 were adjudicated as not aneurysm related/not reintervention related). In 31 of 32 (97%) patients, reintervention success was achieved. CONCLUSIONS: Reinterventions after F/B-EVAR were necessary in 26% of patients, most commonly for type III endoleaks and target artery complications. Whereas all but one reintervention was successful, many of these required complex procedures with significant morbidity and mortality. Development of strategies to eliminate type III endoleaks by improving component junction integrity and to ensure target artery primary patency are key next steps in the evolution of F/B-EVAR.

Increasing the number of integrated vascular surgery residency positions is important to address the impending shortage of vascular surgeons in the United States.

OBJECTIVE: The demand for vascular surgeons is expected to far exceed the current supply. In an attempt to decrease the training duration and to address the impending shortage, integrated vascular surgery residencies were approved and have expanded nationally. Meanwhile, vascular fellowships have continued to matriculate approximately 120 trainees annually. We sought to evaluate the supply and demand for integrated vascular residency positions as well as changes in the quality of applicants. METHODS: We conducted a retrospective review of national data compiled by the Association of American Medical Colleges and the National Resident Matching Program regarding integrated vascular surgery residency programs (2008-2015) and fellowships (2007-2016). Variables reviewed included the total number of applicants, sex, U.S. vs international medical school enrollment, applications per program, and applicants per position. In addition, we conducted a retrospective review of applicants to the University of Massachusetts Medical School integrated vascular surgery residency program from 2008 to 2015 to examine these variables and United States Medical Licensing Examination Step 1 and Step 2 CK scores over time. RESULTS: The number of vascular surgery integrated residency positions increased from 4 in 2008 to 56 in 2015. Concurrently, the number of integrated residency applicants grew from 112 in 2008 to 434 in 2015. This increase has been predominantly driven by a 575% increase in U.S. graduate applicants and a 170% increase in women applicants. The percentage of international medical graduates has decreased by 17% during the study period. The total number of applicants per residency position increased from 5.9 to 7.8. Meanwhile, the number of vascular surgery fellowship positions remained stable with an applicant to position ratio near 1:1. At the University of Massachusetts Medical School, the mean United States Medical Licensing Examination Step 1 (226 to 235) and Step 2 CK (237 to 243) scores among integrated residency applicants have improved annually and typically exceed the national average among U.S. applicants who have matched in their preferred specialty. CONCLUSIONS: Since the approval of a primary certificate in vascular surgery and the subsequent rollout of integrated vascular residency programs, the number of residency programs and the quality of residency applicants have continued to increase. Demand from medical school applicants vastly outweighs the current supply of training positions by eightfold. In contrast, demand from fellowship applicants matches the supply of fellowship positions. The matriculation of additional trainees must be met with continued expansion of the integrated vascular surgery residency pathway to manage future public health needs.

Outcomes of fenestrated and branched endovascular repair of complex abdominal and thoracoabdominal aortic aneurysms.

BACKGROUND: More than 80% of infrarenal aortic aneurysms are treated by endovascular repair. However, adoption of fenestrated and branched endovascular repair for complex aortic aneurysms has been limited, despite high morbidity and mortality associated with open repair. There are few published reports of consecutive outcomes, inclusive of all fenestrated and branched endovascular repairs, starting from the inception of a complex aortic aneurysm program. Therefore, we examined a single center's consecutive experience of fenestrated and branched endovascular repair of complex aortic aneurysms. METHODS: This is a single-center, prospective, observational cohort study evaluating 30-day and 1-year outcomes in all consecutive patients who underwent fenestrated and branched endovascular repair of complex aortic aneurysms (definition: requiring one or more fenestrations or branches). Data were collected prospectively through an Institutional Review Board-approved registry and a physician-sponsored investigational device exemption clinical trial (G130210). RESULTS: We performed 100 consecutive complex endovascular aortic aneurysm repairs (November 2010 to March 2016) using 58 (58%) commercially manufactured custom-made devices and 42 (42%) physician-modified devices to treat 4 (4%) common iliac, 42 (42%) juxtarenal, 18 (18%) pararenal, and 36 (36%) thoracoabdominal aneurysms (type I, n = 1; type II, n = 4; type III, n = 12; type IV, n = 18; arch, n = 1). The repairs included 309 fenestrations, branches, and scallops (average of 3.1 branch arteries/case). All patients had 30-day follow-up for 30-day event rates: three (3%) deaths; six (6%) target artery occlusions; five (5%) progressions to dialysis; eight (8%) access complications; one (1%) paraparesis; one (1%) bowel ischemia; and no instances of myocardial infarction, paralysis, or stroke. Of 10 type I or type III endoleaks, 8 resolved (7 with secondary intervention, 1 without intervention). Mean follow-up time was 563 days (interquartile range, 156-862), with three (3%) patients lost to follow-up. On 1-year Kaplan-Meier analysis, survival was 87%, freedom from type I or type III endoleak was 97%, target vessel patency was 92%, and freedom from aortic rupture was 100%. Average lengths of intensive care unit stay and inpatient stay were 1.4 days (standard deviation, 3.3) and 3.6 days (standard deviation, 3.6), respectively. CONCLUSIONS: These results show that complex aortic aneurysms can now be treated with minimally invasive fenestrated and branched endovascular repair. Endovascular technologies will likely continue to play an increasingly important role in the management of patients with complex aortic aneurysm disease.

Trends in use of the only Food and Drug Administration-approved commercially available fenestrated endovascular aneurysm repair device in the United States.

BACKGROUND: Fenestrated endografts are customized, patient-specific, endovascular devices with potential to significantly reduce morbidity and mortality of short-neck infrarenal and juxtarenal abdominal aortic aneurysm repair. The Zenith fenestrated endovascular graft (ZFEN) for abdominal aortic aneurysms (Cook Medical, Bloomington, Ind), Food and Drug Administration-approved in 2012, remains the only fenestrated device available in the United States. This technology is among the most technically complex catheter-based procedures and, therefore, inherently associated with serious risk for device-related complications. We sought to define patterns of physician and hospital adoption of ZFEN. METHODS: Deidentified datasets containing numbers of physicians trained, orders by physicians and hospitals, and designs (fenestration/scallop configuration) was provided for U.S. ZFEN devices ordered (April 2012-August 2015). We evaluated the number of physicians trained, the number of devices ordered, hospital characteristics, and fenestration/scallop design configurations. Cook Medical assembled the datasets but played no role in study design, analysis, or interpretation of data. RESULTS: Between April 2012 and August 2015, 553 physicians attended formal ZFEN training sessions, 388 (70%) of whom ordered a total of 2669 devices. An increase in orders per month (nine in June 2012 and 91 in August 2015, 911% growth; P < .001) and in number of physicians ordering per month (eight in June 2012 and 62 in August 2015, 675% growth; P < .001) was observed. Teaching hospitals, representing all U.S. regions (Midwest 927, 35%; South 799, 30%; Northeast 547, 20%; West 396, 15%), accounted for 1703 (64%) ZFEN orders. Of 553 trained physicians, 165 (30%) ordered no devices, 116 (21%) ordered 1 device, 144 (26%) ordered 2-5 devices, 61 (11%) ordered 6-10 devices, 39 (7%) ordered 11-20, and 28 (5%) ordered >20 devices. For physicians contributing >6 months of data (n = 336), the average number of devices ordered per year was three (standard deviation, 4); 272 (81%) ordered ≤ 5 devices/year, 15 (4.5%) ordered 11-20 devices/year, and 3 (0.9%) ordered >20 devices/year. Of devices with design details available (2618 of 2669; 98%), most common designs were 2 small fenestrations/1 scallop (1443; 55%), 2 small fenestrations/1 large fenestration (568; 22%), 1 small fenestration/1 scallop (173, 6.6%), and 2 small fenestrations (169; 6.5%). The average number of target vessels incorporated in each design was 2.7/device; 2071 (79%) incorporated three, 398 (15%) incorporated two. CONCLUSIONS: Since 2012, ZFEN has demonstrated a ninefold increase in monthly orders, with 553 physicians trained. Unlike the experience of rapid dissemination seen with infrarenal endografts, only 28 (5%) physicians have ordered >20, whereas 165 (30%) have ordered none, and 272 (81%) ordered ≤ 5 devices/year. Assuming that volume, in general, correlates with outcomes, this adoption pattern raises questions whether fenestrated technology should be regionalized to high-volume centers.

An intensive vascular surgical skills and simulation course for vascular trainees improves procedural knowledge and self-rated procedural competence.

BACKGROUND: Surgical skills and simulation courses are emerging to meet the demand for vascular simulation training for vascular surgical skills, but their educational effect has not yet been described. We sought to determine the effect of an intensive vascular surgical skills and simulation course on the procedural knowledge and self-rated procedural competence of vascular trainees and to assess participant feedback regarding the course. METHODS: Participants underwent a 1.5-day course covering open and endovascular procedures on high-fidelity simulators and cadavers. Before and after the course, participants completed a written test that assessed procedural knowledge concerning index open vascular and endovascular procedures. Participants also assessed their own procedural competence in open and endovascular procedures on a 5-point Likert scale (1: no ability to perform, 5: performs independently). Scores before and after the course were compared among postgraduate year (PGY) 1-2 and PGY 3-7 trainees. Participants completed a survey to rate the relevance and realism of open and endovascular simulations. RESULTS: Fifty-eight vascular integrated residents and vascular fellows (PGY 1-7) completed the course and all assessments. After course participation, procedural knowledge scores were significantly improved among PGY 1-2 residents (50% correct before vs 59% after; P < .0001) and PGY 3-7 residents (52% correct before vs 63% after; P = .003). Self-rated procedural competence was significantly improved among PGY 1-2 (2.2 ± 0.1 before vs 3.1 ± 0.1 after; P < .0001) and PGY 3-7 (3.0 ± 0.1 before vs 3.7 ± 0.1 after; P ≤ .0001). Self-rated procedural competence significantly improved for both endovascular (2.4 ± 0.1 before vs 3.3 ± 0.1 after; P < .0001) and open procedures (2.7 ± 0.1 before vs 3.5 ± 0.1 after; P < .0001). More than 93% of participants reported they were "satisfied" or "very satisfied" with the relevance and realism of the open and endovascular simulations. All participants reported they would recommend the course to other trainees. CONCLUSIONS: This intensive vascular surgical skills and simulation course improved procedural knowledge concerning index open vascular and endovascular procedures among PGY 1-2 and PGY 3-7 trainees. The course also improved self-rated procedural competence across all levels of training for open and endovascular procedures. Trainees rated the value of a surgical skills and simulation course highly. These results support strong consideration for the implementation of similar intensive simulation and surgical skills courses with ongoing objective assessment of their educational effect.

A multidisciplinary approach to vascular surgery procedure coding improves coding accuracy, work relative value unit assignment, and reimbursement.

BACKGROUND: Vascular surgery procedural reimbursement depends on accurate procedural coding and documentation. Despite the critical importance of correct coding, there has been a paucity of research focused on the effect of direct physician involvement. We hypothesize that direct physician involvement in procedural coding will lead to improved coding accuracy, increased work relative value unit (wRVU) assignment, and increased physician reimbursement. METHODS: This prospective observational cohort study evaluated procedural coding accuracy of fistulograms at an academic medical institution (January-June 2014). All fistulograms were coded by institutional coders (traditional coding) and by a single vascular surgeon whose codes were verified by two institution coders (multidisciplinary coding). The coding methods were compared, and differences were translated into revenue and wRVUs using the Medicare Physician Fee Schedule. Comparison between traditional and multidisciplinary coding was performed for three discrete study periods: baseline (period 1), after a coding education session for physicians and coders (period 2), and after a coding education session with implementation of an operative dictation template (period 3). The accuracy of surgeon operative dictations during each study period was also assessed. An external validation at a second academic institution was performed during period 1 to assess and compare coding accuracy. RESULTS: During period 1, traditional coding resulted in a 4.4% (P = .004) loss in reimbursement and a 5.4% (P = .01) loss in wRVUs compared with multidisciplinary coding. During period 2, no significant difference was found between traditional and multidisciplinary coding in reimbursement (1.3% loss; P = .24) or wRVUs (1.8% loss; P = .20). During period 3, traditional coding yielded a higher overall reimbursement (1.3% gain; P = .26) than multidisciplinary coding. This increase, however, was due to errors by institution coders, with six inappropriately used codes resulting in a higher overall reimbursement that was subsequently corrected. Assessment of physician documentation showed improvement, with decreased documentation errors at each period (11% vs 3.1% vs 0.6%; P = .02). Overall, between period 1 and period 3, multidisciplinary coding resulted in a significant increase in additional reimbursement ($17.63 per procedure; P = .004) and wRVUs (0.50 per procedure; P = .01). External validation at a second academic institution was performed to assess coding accuracy during period 1. Similar to institution 1, traditional coding revealed an 11% loss in reimbursement ($13,178 vs $14,630; P = .007) and a 12% loss in wRVU (293 vs 329; P = .01) compared with multidisciplinary coding. CONCLUSIONS: Physician involvement in the coding of endovascular procedures leads to improved procedural coding accuracy, increased wRVU assignments, and increased physician reimbursement.

Results of repeated percutaneous interventions on failing arteriovenous fistulas and grafts and factors affecting outcomes.

OBJECTIVE: Repeated percutaneous interventions on failing arteriovenous fistulas (AVFs) and arteriovenous grafts (AVGs) for hemodialysis are common, but the outcomes are largely unknown. We sought to determine the results of the second percutaneous intervention on failing AVGs and AVFs and to identify factors associated with loss of patency. METHODS: For the purpose of this study, the second percutaneous intervention was identified as the index procedure. We reviewed the second percutaneous interventions on failing AVFs and AVGs at a single institution between 2007 and 2013. Patient comorbidities, graft or fistula configuration, lesion characteristics, and procedural characteristics of the intervention performed were analyzed with respect to technical success, primary patency, primary assisted patency, and secondary patency. Patency was defined per Society for Vascular Surgery recommended reporting standards and was determined from the time of the index procedure. Cox proportional hazards multivariable modeling was performed to identify independent determinants of loss of patency. RESULTS: Among 91 patients, 96 second-time percutaneous interventions were performed on 52 AVFs and 44 AVGs. Patients included 56% men and 44% women with a mean age of 64 ± 17 years. The lesions intervened on were primarily located along the accessed portion of the outflow in AVFs and within the length of the graft and at the venous anastomosis in AVGs. Transluminal angioplasty alone was performed in 82 procedures (85%), and uncovered or covered stents were placed in 15 procedures (16%). Pharmacomechanical thrombectomy was performed in 32 patients (34%) and was more commonly performed in AVGs compared with AVFs (53% vs 17%; P = .0002). Technical success was achieved in 90 procedures (97%; n = 92). One-year primary patency, assisted primary patency, and secondary patency rates were 35%, 86%, and 86%, respectively. One-year primary patency did not differ between AVFs and AVGs, but secondary patency was lower for AVG in comparison to AVF (P = .04). On multivariable analysis, only the need for pharmacomechanical thrombectomy significantly predicted failure of primary patency (hazard ratio, 2.6; 95% confidence interval, 1.6-4.3). The presence of an AVG rather than an AVF independently predicted failure of secondary patency (hazard ratio, 2.9; 95% confidence interval, 1.0-8.2). CONCLUSIONS: The second percutaneous interventions on AVFs and AVGs are associated with excellent technical success but poor primary patency. The need for pharmacomechanical thrombectomy predicts the need for additional percutaneous intervention to maintain patency. With additional interventions, acceptable secondary patency out to 5 years can be achieved, although AVGs have inferior secondary patency to AVFs. To develop optimal practice management algorithms, the effectiveness of repeated percutaneous interventions for failing AVGs and AVFs vs creation of a new access should be further investigated.

Endovascular repair of ruptured abdominal aortic aneurysms does not reduce later mortality compared with open repair.

OBJECTIVE: Endovascular aneurysm repair (EVAR) of ruptured abdominal aortic aneurysms (RAAAs) reduces in-hospital mortality compared with open repair (OR), but it is unknown whether EVAR reduces long-term mortality. We hypothesized that EVAR of RAAA would independently reduce long-term mortality compared with OR. METHODS: The Vascular Quality Initiative database (2003-2013) was used to determine Kaplan-Meier 1-year and 5-year mortality after EVAR and OR of RAAA. Multivariate analysis was performed to identify patient and operative characteristics associated with mortality at 1 year and 5 years after RAAA repair. RESULTS: Among 590 patients who underwent EVAR and 692 patients who underwent OR of RAAA, the lower mortality seen in the hospital after EVAR (EVAR 23% vs OR 35%; P < .001) persisted at 1 year (EVAR 34% vs OR 42%; P = .001) and 5 years (EVAR 50% vs OR 58%; P = .003) after repair. After adjusting for patient and operative characteristics, EVAR did not independently reduce mortality at 1 year (hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.7-1.1) or 5 years (HR, 0.95; 95% CI, 0.77-1.2) compared with OR. Dialysis dependence (HR, 3.9; 95% CI, 1.8-8.6), home oxygen use (HR, 1.9; 95% CI, 1.3-2.7), cardiac ejection fraction <50% (HR, 1.5; 95% CI, 1.03-2.1), female gender (HR, 1.3; 95% CI, 1.04-1.6), and age (HR, 1.06; 95% CI, 1.05-1.08 per 5 years) as well as cardiac arrest (HR, 3.4; 95% CI, 2.5-4.5), loss of consciousness (HR, 1.7; 95% CI, 1.3-2.2), and preoperative systolic blood pressure <90 mm Hg (HR, 1.4; 95% CI, 1.1-1.8) on admission predicted mortality at 1 year and 5 years after RAAA repair. Type I endoleak (HR, 2.2; 95% CI, 1.2-3.8) also predicted mortality at 1 year. CONCLUSIONS: EVAR does not independently reduce long-term mortality compared with OR. Patient comorbidities and indices of shock on admission are the primary independent determinants of long-term mortality. However, the lower early mortality observed in the Vascular Quality Initiative for patients selected to undergo EVAR of RAAA compared with patients selected for OR is sustained over time, suggesting that EVAR for RAAA is beneficial in appropriate candidates. Better elucidation of the key selection factors, including aneurysm anatomy, is needed to best select patients for EVAR and OR to reduce long-term mortality.

Contemporary Management of Acute Aortic Occlusion Has Evolved but Outcomes Have Not Significantly Improved.

BACKGROUND: Most existing series of acute aortic occlusion (AAO) predate the changes in surgical and endovascular therapy of the last 2 decades. We examined the contemporary management and outcomes of AAO. METHODS: We reviewed consecutive patients with AAO at a tertiary referral center from 2004 to 2012. Outcomes were stratified and compared according to etiology and procedure performed. RESULTS: AAO in 29 patients was due to in situ thrombosis in 21 (72%) and embolism in 8 (28%) patients. Vascular patients with embolism were on average older (77 ± 7 vs. 66 ± 12 years, P = 0.02) and had higher rates of atrial fibrillation (100% vs. 20%, P = 0.0002) and congestive heart failure (75% vs. 0%, P = 0.0001) in comparison with those with in situ thrombosis. Neurologic deficit was present in 16 (55%) patients. Six patients (21%) presented with bilateral paresis/paralysis secondary to spinal cord or lumbosacral plexus ischemia, and primary neurologic etiology was investigated before vascular consultation was obtained in 4 of these 6 patients. Of the 29 patients, 28 (97%) underwent revascularization including transfemoral embolectomy (n = 6), transperitoneal aortoiliac thrombectomy (n = 2), axillobifemoral bypass (n = 10), aortobifemoral bypass (n = 6), and endovascular therapy including thrombolysis, angioplasty ± stenting (n = 4). In-hospital mortality was 31% and did not vary significantly according to etiology (embolism 38% vs. in situ thrombosis 29%, P = 0.67). In-hospital mortality varied widely according to procedure (transfemoral embolectomy 50%, aortoiliac thrombectomy 100%, axillobifemoral bypass 30%, aortobifemoral bypass 0%, and endovascular therapy 25%, P = 0.08). Major morbidity (59%), length of stay (8.6 ± 8.0 days), and discharge to a rehabilitation facility (50%) did not vary by etiology or procedure. At a media follow-up of 361 ± 460 days (range 3-2014), overall survival was 42%. There were no amputations among 20 survivors of initial hospitalization. CONCLUSIONS: AAO is now more commonly caused by in situ thrombosis rather than embolism. A high index of suspicion for AAO is required for prompt diagnosis and treatment, particularly when patients present with profound lower extremity neurologic deficit. In comparison with previous reports, the contemporary management of AAO includes increased use of axillobifemoral bypass and now involves endovascular revascularization, although a variety of open surgical procedures are utilized. However, the in-hospital mortality and morbidity of AAO has not decreased significantly over the last 2 decades and mid-term survival remains limited. Further study is required to identify strategies that improve outcomes after AAO.

Inhibition of p38 Mitogen-Activated Protein Kinase Enhances the Apoptosis Induced by Oxidized Low-Density Lipoprotein in Endothelial Progenitor Cells.

Oxidized low-density lipoprotein (oxLDL) is an important risk factor in the development of atherosclerosis. oxLDL has been shown to decrease endothelial progenitor cell (EPC) number by inducing apoptosis. p38 mitogen-activated protein kinase (MAPK) was shown to be activated by oxLDL and participated in the regulation of EPC number and function. However, the role of p38 remains unknown. Here, we show that oxLDL-induced p38 phosphorylation in EPCs is time and dose dependent. Treatment with antioxidant N-acetyl cysteine restored oxLDL-induced p38 phosphorylation to basal levels. LOX-1-blocking antibody also significantly decreased oxLDL-induced p38 phosphorylation. Interestingly, TUNEL staining showed that pretreatment with the p38 inhibitor SB203580 further increased oxLDL-induced apoptosis in EPCs. In accordance with these findings, pretreatment with SB203580 further attenuated Akt phosphorylation in EPCs challenged with oxLDL, indicating an interaction between Akt and p38 MAPK pathways. In agreement, inhibition of p38 MAPK further attenuated Akt phosphorylation and increased apoptosis in EPCs isolated from hypercholesterolemic ApoE-/- mice. In conclusion, p38 MAPK serves as an anti-apoptotic pathway by supporting Akt activity when EPCs are challenged with oxLDL.

Developing a complex endovascular fenestrated and branched aortic program.

In 2008, the top priority in our division's 5-year strategic plan was "to become an internationally recognized center of excellence for the endovascular treatment of complex aortic pathology extending from the aortic valve to the external iliac artery." Five components were identified as "most critical" to achieve this strategic priority: (1) training at centers of excellence in complex endovascular repair; (2) industry partnership to improve access to developing technologies; (3) a fully integrated team approach with one leader involved in all steps of all cases; (4) prospective data collection; and (5) development and implementation of a physician-sponsored investigational device exemption for juxtarenal, pararenal, and thoracoabdominal aneurysms. We have now performed 49 repairs (16 commercially manufactured devices, 33 physician-modified devices) for 3 common iliac, 20 juxtarenal, 9 pararenal, and 17 thoracoabdominal aneurysms, using 142 fenestrations, branches, and scallops. All patients had complete 30-day follow-up for calculation of 30-day events. Kaplan-Meier analysis was used to calculate 1-year events. In 5 years, we developed a successful complex endovascular aortic program that uses fenestrated/branched repair techniques. A focused team strategic planning approach to program development is an effective way for vascular surgery divisions to gain experience and expertise with new complex technologies while ensuring acceptable patient outcomes.

The Agency for Healthcare Research and Quality Inpatient Quality Indicator #11 overall mortality rate does not accurately assess mortality risk after abdominal aortic aneurysm repair.

OBJECTIVE: The Agency for Healthcare Research and Quality (AHRQ) Inpatient Quality Indicator (IQI) #11, abdominal aortic aneurysm (AAA) repair mortality rate, is a measure of hospital quality that is publically reported but has not been externally validated. Because the IQI #11 overall mortality rate includes both intact and ruptured aneurysms and open and endovascular repair, we hypothesized that IQI #11 overall mortality rate does not provide accurate assessment of mortality risk after AAA repair and that AAA mortality cannot be accurately assessed by a single quality measure. METHODS: Using AHRQ IQI software version 4.2, we calculated observed (O) and expected (E) mortality rates for IQI #11 for all hospitals performing more than 10 AAA repairs per year in the Nationwide Inpatient Sample for the years 2007 to 2011. We used Spearman correlation coefficient to compare expected rates as determined by IQI #11 overall mortality rate risk adjustment methodology and observed rates for all AAA repairs in four cohorts stratified by aneurysm stability (ruptured vs intact) and method of repair (open vs endovascular). RESULTS: Among 187,773 AAA repairs performed at 1268 U.S. hospitals, hospitals' IQI #11 overall expected rates correlated poorly with their observed rates (E: 5.0% ± 4.4% vs O: 6.0% ± 9.8%; r = .49). For ruptured AAAs, IQI #11 overall mortality rate methodology underestimated the mortality risk of open repair (E: 34% ± 7.2% vs O: 40.1% ± 38.2%; r = 0.20) and endovascular repair (E: 24.8% ± 9% vs O: 27.3% ± 37.9%; r = 0.08). For intact AAA repair, IQI #11 overall mortality rate methodology underestimated the mortality risk of open repair (E: 4.3% ± 2.4% vs O: 6.3% ± 16.1%; r = .24) but overestimated the mortality risk of endovascular repair (E: 1.3% ± 0.8% vs O: 1.1% ± 3.7%; r = 0.25). Hospitals' observed mortality rates after intact AAA repair were not correlated with their mortality rates after ruptured AAA repair (r = 0.03). CONCLUSIONS: IQI #11 overall mortality rate fails to provide accurate assessment of inpatient mortality risk after AAA repair. Thus, it is inappropriate to use IQI #11 overall mortality rate for quality reporting. The accuracy of separate quality measures that assess mortality risk after repair of ruptured and intact AAAs, stratified by the use of open or endovascular repair, should be examined.

National variation in preoperative imaging, carotid duplex ultrasound criteria, and threshold for surgery for asymptomatic carotid artery stenosis.

OBJECTIVE: Carotid endarterectomy (CEA) for asymptomatic carotid artery stenosis is among the most common procedures performed in the United States. However, consensus is lacking regarding optimal preoperative imaging, carotid duplex ultrasound criteria, and ultimately, the threshold for surgery. We sought to characterize national variation in preoperative imaging, carotid duplex ultrasound criteria, and threshold for surgery for asymptomatic CEA. METHODS: The Society for Vascular Surgery Vascular Quality Initiative (VQI) database was used to identify all CEA procedures performed for asymptomatic carotid artery stenosis between 2003 and 2014. VQI currently captures 100% of CEA procedures performed at >300 centers by >2000 physicians nationwide. Three analyses were performed to quantify the variation in (1) preoperative imaging, (2) carotid duplex ultrasound criteria, and (3) threshold for surgery. RESULTS: Of 35,695 CEA procedures in 33,488 patients, the study cohort was limited to 19,610 CEA procedures (55%) performed for asymptomatic disease. The preoperative imaging modality used before CEA varied widely, with 57% of patients receiving a single preoperative imaging study (duplex ultrasound imaging, 46%; computed tomography angiography, 7.5%; magnetic resonance angiography, 2.0%; cerebral angiography, 1.3%) and 43% of patients receiving multiple preoperative imaging studies. Of the 16,452 asymptomatic patients (89%) who underwent preoperative duplex ultrasound imaging, there was significant variability between centers in the degree of stenosis (50%-69%, 70%-79%, 80%-99%) designated for a given peak systolic velocity, end diastolic velocity, and internal carotid artery-to-common carotid artery ratio. Although 68% of CEA procedures in asymptomatic patients were performed for an 80% to 99% stenosis, 26% were performed for a 70% to 79% stenosis, and 4.1% were performed for a 50% to 69% stenosis. At the surgeon level, the range in the percentage of CEA procedures performed for a <80% asymptomatic carotid artery stenosis is from 0% to 100%. Similarly, at the center level, institutions range in the percentage of CEA procedures performed for a <80% asymptomatic carotid artery stenosis from 0% to 100%. CONCLUSIONS: Despite CEA being an extremely common procedure, there is widespread variation in the three primary determinants-preoperative imaging, carotid duplex ultrasound criteria, and threshold for surgery-of whether CEA is performed for asymptomatic carotid stenosis. Standardizing the approach to care for asymptomatic carotid artery stenosis will mitigate the significant downstream effects of this variation on health care costs.

In patients stratified by preoperative risk, endovascular repair of ruptured abdominal aortic aneurysms has a lower in-hospital mortality and morbidity than open repair.

OBJECTIVE: Previous studies have reported that endovascular repair (EVAR) of ruptured abdominal aortic aneurysms (RAAAs) has lower postoperative mortality than open repair (OR). However, comparisons involved heterogeneous populations that lacked adjustment for preoperative risk. We hypothesize that for RAAA patients stratified by a validated measure of preoperative mortality risk, EVAR has a lower in-hospital mortality and morbidity than does OR. METHODS: In-hospital mortality and morbidity after EVAR and OR of RAAA were compared in patients from the Vascular Quality Initiative (2003-2013) stratified by the validated Vascular Study Group of New England RAAA risk score into low-risk (score 0-1), medium-risk (score 2-3), and high-risk (score 4-6) groups. RESULTS: Among 514 patients who underwent EVAR and 651 patients who underwent OR of RAAA, EVAR had lower in-hospital mortality (25% vs 33%, P = .001). In risk-stratified patients, EVAR trended toward a lower mortality in the low-risk group (n = 626; EVAR, 10% vs OR, 15%; P = .07), had a significantly lower mortality in the medium-risk group (n = 457; EVAR, 37% vs OR, 48%; P = .02), and no advantage in the high-risk group (n = 82; EVAR, 95% vs OR, 79%; P = .17). Across all risk groups, cardiac complications (EVAR, 29% vs OR, 38%; P = .001), respiratory complications (EVAR, 28% vs OR, 46%; P < .0001), renal insufficiency (EVAR, 24% vs OR, 38%; P < .0001), lower extremity ischemia (EVAR, 2.7% vs OR, 8.1%; P < .0001), and bowel ischemia (EVAR, 3.9% vs OR, 10%; P < .0001) were significantly lower after EVAR than after OR. Across all risk groups, median (interquartile range) intensive care unit length of stay (EVAR, 2 [1-5] days vs OR, 6 [3-13] days; P < .0001) and hospital length of stay (EVAR, 6 [4-12] days vs OR, 13 [8-22] days; P < .0001) were lower after EVAR. CONCLUSIONS: This novel risk-stratified comparison using a national clinical database showed that EVAR of RAAA has a lower mortality and morbidity compared with OR in low-risk and medium-risk patients and that EVAR should be used to treat these patients when anatomically feasible. For RAAA patients at the highest preoperative risk, there is no benefit to using EVAR compared with OR.

Follow-up compliance after endovascular abdominal aortic aneurysm repair in Medicare beneficiaries.

OBJECTIVE: Lifelong imaging follow-up is essential to the safe and appropriate management of patients who undergo endovascular abdominal aortic aneurysm repair (EVAR). We sought to evaluate the rate of compliance with imaging follow-up after EVAR and to identify factors associated with being lost to imaging follow-up. METHODS: We identified a 20% sample of continuously enrolled Medicare beneficiaries who underwent EVAR between 2001 and 2008. Using data through 2010 from Medicare Inpatient, Outpatient, and Carrier files, we identified all abdominal imaging studies that may have been performed for EVAR follow-up. Patients were considered lost to annual imaging follow-up if they did not undergo any abdominal imaging study within their last 2 years of follow-up. Multivariable models were constructed to identify independent factors associated with being lost to annual imaging follow-up. RESULTS: Among 19,962 patients who underwent EVAR, the incidence of loss to annual imaging follow-up at 5 years after EVAR was 50%. Primary factors associated with being lost to annual imaging follow-up were advanced age (age 65-69 years, reference; age 75-79 years: hazard ratio [HR], 1.23; 95% confidence interval [CI], 1.15-1.32; age 80-85 years: HR, 1.45; 95% CI, 1.35-1.55; age >85 years: HR, 2.03; 95% CI, 1.88-2.20) and presentation with an urgent/emergent intact aneurysm (HR, 1.27; 95% CI, 1.20-1.35) or ruptured aneurysm (HR, 1.84; 95% CI, 1.63-2.08). Additional independent factors included several previously diagnosed chronic diseases and South and West regions of the United States. CONCLUSIONS: Annual imaging follow-up compliance after EVAR in the United States is significantly below recommended levels. Quality improvement efforts to encourage improved compliance with imaging follow-up, especially in older patients with multiple comorbidities and in those who underwent EVAR urgently or for rupture, are necessary.