Edward J. Arous

Complications After Pancreatectomy for Neuroendocrine Tumors: A National Study

BACKGROUND Although resection of pancreatic neuroendocrine tumors (PNETs) has a demonstrated survival advantage, further evaluation of the overall morbidity of these procedures is needed. Our objective was to examine a composite outcome of major postoperative complications, including in-hospital mortality. MATERIALS AND METHODS The Nationwide Inpatient Sample (NIS), 1998-2006, was used to identify all patients with a diagnosis of PNET who had undergone pancreatectomy. Candidate predictors consisted of patient and hospital characteristics. Univariate analyses included chi(2) tests. Multivariate analyses were performed with logistic regression to determine which predictors were independently associated with the composite outcome. RESULTS A total of 463 (2274 nationally weighted) patients were identified. Overall composite postoperative complication rate was 29.6%. The majority of complications involved infections (11.1%), digestive complications (8.8%), or pulmonary compromise (7.3%). In-hospital mortality rate was 1.7%. High Charlson comorbidity score, procedure type of Whipple or total pancreatectomy, and urban hospital location were all associated with significantly increased complication rate. Logistic regression analysis demonstrated: Charlson score of > or =3 versus score of 0 (adjusted odds ratio (OR) 4.1, 95% confidence interval (CI) 2.1-8.3), surgery type of Whipple or total pancreatectomy versus partial pancreatectomy (adjusted OR 2.7, 95% CI 1.8-4.1), and hospital location of urban versus rural (adjusted OR 4.5, 95% CI 3.0-6.9). CONCLUSIONS While in-hospital mortality rates are low for surgical resection of PNETs, there is a considerable overall postoperative complication rate associated with these procedures. Careful patient and surgery selection may be the key to a surgical treatment approach for PNETs that may optimize outcomes.

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.

Electronic medical record: research tool for pancreatic cancer

BACKGROUND A novel data warehouse based on automated retrieval from an institutional health care information system (HIS) was made available to be compared with a traditional prospectively maintained surgical database. METHODS A newly established institutional data warehouse at a single-institution academic medical center autopopulated by HIS was queried for International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) diagnosis codes for pancreatic neoplasm. Patients with ICD-9-CM diagnosis codes for pancreatic neoplasm were captured. A parallel query was performed using a prospective database populated by manual entry. Duplicated patients and those unique to either data set were identified. All patients were manually reviewed to determine the accuracy of diagnosis. RESULTS A total of 1107 patients were identified from the HIS-linked data set with pancreatic neoplasm from 1999-2009. Of these, 254 (22.9%) patients were also captured by the surgical database, whereas 853 (77.1%) patients were only in the HIS-linked data set. Manual review of the HIS-only group demonstrated that 45.0% of patients were without identifiable pancreatic pathology, suggesting erroneous capture, whereas 36.3% of patients were consistent with pancreatic neoplasm and 18.7% with other pancreatic pathology. Of the 394 patients identified by the surgical database, 254 (64.5%) patients were captured by HIS, whereas 140 (35.5%) patients were not. Manual review of patients only captured by the surgical database demonstrated 85.9% with pancreatic neoplasm and 14.1% with other pancreatic pathology. Finally, review of the 254 patient overlap demonstrated that 80.3% of patients had pancreatic neoplasm and 19.7% had other pancreatic pathology. CONCLUSIONS These results suggest that cautious interpretation of administrative data rely only on ICD-9-CM diagnosis codes and clinical correlation through previously validated mechanisms.

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.

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.

Peripheral atherectomy practice patterns in the United States from the Vascular Quality Initiative

Objective: Peripheral atherectomy has been shown to have technical success in single‐arm studies, but clinical advantages over angioplasty and stenting have not been demonstrated, leaving its role unclear. We sought to describe patterns of atherectomy use in a real‐world U.S. cohort to understand how it is currently being applied. Methods: The Vascular Quality Initiative was queried to identify all patients who underwent peripheral vascular intervention from January 2010 to September 2016. Descriptive statistics were performed to analyze demographics of the patients, comorbidities, indication, treatment modalities, and lesion characteristics. The intermittent claudication (IC) and critical limb ischemia (CLI) cohorts were analyzed separately. Results: Of 85,605 limbs treated, treatment indication was IC in 51% (n = 43,506) and CLI in 49% (n = 42,099). Atherectomy was used in 15% (n = 13,092) of cases, equivalently for IC (15%; n = 6674) and CLI (15%; n = 6418). There was regional variation in use of atherectomy, ranging from a low of 0% in one region to a high of 32% in another region. During the study period, there was a significant increase in the proportion of cases that used atherectomy (11% in 2010 vs 18% in 2016; P < .0001). Compared with nonatherectomy cases, those with atherectomy use had higher incidence of prior peripheral vascular intervention (IC, 55% vs 43% [P < .0001]; CLI, 47% vs 41% [P < .0001]), greater mean number of arteries treated (IC, 1.8 vs 1.6 [P < .0001]; CLI, 2.1 vs 1.7 [P < .0001]), and lower proportion of prior leg bypass (IC, 10% vs 14% [P < .0001]; CLI, 11% vs 17% [P < .0001]). There was lower incidence of failure to cross the lesion (IC, 1% vs 4% [P < .0001]; CLI, 4% vs 7% [P < .0001]) but higher incidence of distal embolization (IC, 1.9% vs 0.8% [P < .0001]; CLI, 3.0% vs 1.4% [P < .0001]) and, in the CLI cohort, arterial perforation (1.4% vs 1.0%; P = .01). Conclusions: Despite a lack of evidence for atherectomy over angioplasty and stenting, its use has increased across the United States from 2010 to 2016. It is applied equally to IC and CLI populations, with no identifiable pattern of comorbidities or lesion characteristics, suggesting that indications are not clearly delineated or agreed on. This study places impetus on further understanding of the optimal role for atherectomy and its long‐term clinical benefit in the management of peripheral arterial disease.

C10: Poster CompetitionPC094 Increasing the Number of Integrated Vascular Surgery Residency Positions Is Necessary to Address the Impending Shortage of Vascular Surgeons in the United States

three-dimensional (3D) printed aortic model connected to hemodynamic pump. Methods: The study was a prospective validation of EVAR simulation using a 3D printed photopolymer aortic model (Objet500 Connex3 printer; Stratasys, Eden Prairie, Minn) connected to BDC PD-0500 fluid pump (BDC Laboratories, Wheat Ridge, Colo). EVAR procedure metrics were benchmarked in two expert implanters and compared to 20 vascular surgical trainees with different levels of EVAR experience (<20 or >20 cases). All procedures were performed using commercially available stent grafts, fluoroscopic guidance, and high-fidelity simulation of procedural steps with guidewires, catheters, and contrast angiography (Fig). End points included ability to complete the procedure independently and time to deploy aortic component, cannulate the contralateral (CL) gate and complete the repair, total fluoroscopy time, and estimated distance from lowest renal artery. Results: Trainee experience with EVAR prior to the first simulation session was fewer than 5 in 7 trainees, 6 to 20 in 6 and 20 in 7. A total of 22 EVAR simulation procedures were performed by trainees with mean total procedure time of 37 6 12 minutes. Experienced trainees had significantly (P < .003) lower total procedural time (32 6 9 vs 44 6 6 minutes), fluoroscopic time (13 6 5 vs 23 6 8 minutes), and lag time between steps (5 6 2 vs 7 6 2 minutes). All experienced trainees completed the procedure independently in <45 minutes, compared to six (46%) of those with less EVAR experience (P 1⁄4 .016). Among less experienced trainees, only two (15%) completed the entire procedure independently (P < .001). Expert implanters performed significantly better than both trainee groups in nearly all EVAR metrics (Table). Conclusions: EVAR simulation with 3D printed aortic models and hemodynamic pump was feasible and simulated all procedural steps with high fidelity. This model may be applicable for assessment of technical competencies and standard endovascular skill acquisition within vascular surgery training curricula.

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.