Carotid Duplex Velocity Criteria Recommended by the Society of Radiologists in Ultrasound and Endorsed by the Intersocietal Accreditation Commission Lack Predictive Ability for Identifying High-Grade Carotid Artery Stenosis.

BACKGROUND: Carotid duplex is the first-line imaging modality for characterizing degree of carotid stenosis. The Intersocietal Accreditation Commission (IAC), in published guideline documents, has endorsed use of the Society of Radiologists in Ultrasound (SRU) criteria to characterize ≥70% stenosis: peak systolic velocity (PSV) ≥230 cm/s. We sought to perform a validation of the SRU criteria using computed tomography (CT) angiography as a gold standard imaging modality and to perform a sensitivity analysis to determine optimal velocity criteria for identifying ≥80% stenosis. METHODS: We queried all carotid duplex examinations performed at our institution between 2008 and 2017. Patients with ≥70% carotid stenosis, based on previous criteria, were identified. Of these patients, those who also had a CT angiogram of the neck within one year formed the study cohort. Patients who underwent carotid revascularization between the 2 imaging dates were excluded. Degree of stenosis, as reported from the CT angiogram, was considered the true degree of stenosis. Receiver operating characteristic (ROC) curves were generated to evaluate the SRU criteria and to identify the optimal discrimination threshold for high-grade carotid stenosis. RESULTS: Of 37,204 carotid duplex examinations, 3,478 arteries met criteria for ≥70% stenosis. Of these, 344 patients had a CT angiogram within 1 year of the carotid duplex (mean time between studies, 55 days, SD 6.5) and 240 (69.8%) were consistent with ≥80% carotid stenosis. The predictive ability of the SRU criteria to identify ≥70% stenosis was poor, with an area under the ROC curve (AUC) of 0.51. A sensitivity analysis to identify ≥80% stenosis demonstrated the optimal discrimination threshold to be PSV ≥450 cm/s or end diastolic velocity (EDV) ≥120 cm/s, with an AUC of 0.66. CONCLUSIONS: In this validation study, the SRU criteria, endorsed by the IAC, to identify ≥70% carotid stenosis had no predictive value. For detection of ≥80% stenosis, the optimal criteria are a PSV ≥450 cm/s or EDV ≥120 cm/s. This study demonstrates the critical importance of carotid duplex examination validation.

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.

Institutional differences in carotid artery duplex diagnostic criteria result in significant variability in classification of carotid artery stenoses and likely lead to disparities in care.

BACKGROUND: The indications for carotid revascularization are based almost exclusively on the results of carotid duplex ultrasonography. Noninvasive vascular laboratories show large variation in the diagnostic criteria used to classify degree of carotid artery stenosis. We hypothesize that variability of these diagnostic criteria causes significant variation in stenosis classification directly affecting the number of revascularizations and associated costs. METHODS AND RESULTS: The diagnostic criteria to interpret carotid duplex ultrasounds were obtained from 10 New England institutions. All carotid duplex scans performed at our institution were reviewed from 2008 to 2012. Using the diagnostic criteria from each institution, the degree of stenosis that would have been reported was classified as 70% to 99% asymptomatic, 80% to 99% asymptomatic, and 50% to 99% symptomatic. We then calculated the theoretical number of carotid revascularization procedures that this cohort would be offered using each institution's diagnostic criteria and the costs of these procedures based on reimbursement rates. Among 10 614 patients who underwent 15 534 carotid duplex scans, 31 025 arteries were reviewed. Application of the 10 institutions' criteria to the patients from our institution yielded marked variation in the number classified as 70% to 99% asymptomatic (range, 186-2201), 80% to 99% asymptomatic (range, 78-426), and 50% to 99% symptomatic (range, 157-781). If revascularizations were based on these results, costs would range from $2.2 to $26 million, $0.9 to $5.0 million, and $1.9 to $9.2 million, respectively. CONCLUSIONS: Differences in diagnostic criteria to interpret carotid ultrasound result in significant variation in classification of carotid artery stenosis, likely leading to differences in the number and subsequent costs of revascularizations. This theoretical model highlights the need for standardization of carotid duplex criteria.

A randomized comparison of a 3-week and 6-week vascular surgery simulation course on junior surgical residents' performance of an end-to-side anastomosis.

OBJECTIVE: We assessed the effect of an open vascular simulation course on the surgical skill of junior surgical residents in performing a vascular end-to-side anastomosis and determined the course length required for effectiveness. We hypothesized that a 6-week course would significantly increase the surgical skill of junior residents in performing an end-to-side anastomosis, while a 3-week course would not. METHODS: We randomized 37 junior residents (postgraduate year 1 to 3) to a course consisting of three (short course, n = 18) or six (long course, n = 19) consecutive weekly 1-hour teaching sessions. Content focused on instrument recognition and performance of an end-to-side vascular anastomosis using a simulation model. A standardized 50-point vascular skills assessment (SVSA) measured knowledge and technical proficiency. Senior residents (postgraduate year 4 to 5) were tested at baseline. Junior residents were tested at baseline and at 1 and 16 weeks after course completion, and their scores were compared with baseline and senior resident scores. Residents and faculty completed a standardized anonymous evaluation of the course. RESULTS: Baseline scores between short-course and long-course participants were not different. At baseline, junior residents had significantly lower SVSA scores than senior residents (36±7 vs 41.4±2.5; P=.002). One week after course completion, SVSA scores for short-course (43.5±2.9 vs 34.2±7.5; P=.008) and long-course (43.9±5.6 vs 38.3±5.9; P=.006) participants were significantly improved from baseline. SVSA scores decreased slightly at 16 weeks but remained above baseline in short-course (39±6.2 vs 34.2±7.5; P=.03) and long-course (40±4.5 vs 38.3±5.9; P=.08) participants. Long vs short course length did not affect improvement in SVSA scores at 1 or 16 weeks. In short-course and long-course participants, SVSA scores at 1 and 16 weeks were not significantly different from senior resident scores. Course ratings were high, and 95% of residents indicated the course "made them a better surgeon." Residents and faculty felt the educational benefit of the course merited the investment of resources. CONCLUSIONS: An open vascular simulation course consisting of three weekly 1-hour sessions increased the surgical skill of junior residents in performing a vascular end-to-side anastomosis to that of senior residents on a standardized assessment. A 6-week course provided no additional benefit. This study supports the use of an open vascular simulation course to teach vascular surgical skills to junior residents. A course consisting of three 1-hour sessions is an effective and efficient component of a simulation program for junior surgical residents in a busy surgical center.

Surgeon case volume, not institution case volume, is the primary determinant of in-hospital mortality after elective open abdominal aortic aneurysm repair.

OBJECTIVE: Studies analyzing the effects of volume on outcomes after abdominal aortic aneurysm (AAA) repair have primarily centered on institutional volume and not on individual surgeon volume. We sought to determine the relative effects of both surgeon and institution volume on mortality after open and endovascular aneurysm repair (EVAR) for intact AAAs. METHODS: The Nationwide Inpatient Sample (2003-2007) was queried to identify all patients undergoing open repair and EVAR for nonruptured AAAs. To calculate surgeon and institution volume, 11 participating states that record a unique physician identifier for each procedure were included. Surgeon and institution volume were defined as low (first quintile), medium (second, third, or fourth quintile), and high (fifth quintile). Stratification by institution volume and then by surgeon volume was performed to analyze the primary endpoint: in-hospital mortality. Multivariable models were used to evaluate the association of institution and surgeon volume with mortality for open repair and EVAR, controlling for potential confounders. RESULTS: During the study period, 5972 open repairs and 8121 EVARs were performed. For open AAA repair, a significant mortality reduction was associated with both annual institution volume (low <7, medium 7-30, and high >30) and surgeon volume (low ≤ 2, medium 3-9, and high >9). High surgeon volume conferred a greater mortality reduction than did high institution volume. When low and medium volume institutions were stratified by surgeon volume, mortality after open AAA repair was inversely proportional to surgeon volume (8.7%, 3.6%, and 0%; P < .0001, for low, medium, and high-volume surgeons at low-volume institutions; and 6.7%, 4.8%, and 3.3%; P = .02, for low, medium, and high-volume surgeons at medium-volume institutions). High-volume institutions stratified by surgeon volume demonstrated the same trend (5.1%, 3.4%, and 2.8%), but this finding was not statistically significant (P = .57). Multivariable analysis was confirmatory: low surgeon volume independently predicted mortality (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.3-3.1; P < .001); low institution volume did not (P = .1). For EVAR, neither institution volume nor surgeon volume influenced mortality (univariate or multivariable). CONCLUSION: The primary factor driving the mortality reduction associated with case volume after open AAA repair is surgeon volume, not institution volume. Regionalization of AAAs should focus on open repair, as EVAR outcomes are equivalent across volume levels. Payers may need to re-evaluate strategies that encourage open AAA repair at high-volume institutions if specific surgeon volume is not considered.

Endovascular treatment of ruptured abdominal aortic aneurysms in the United States (2001-2006): a significant survival benefit over open repair is independently associated with increased institutional volume.

OBJECTIVE: Endovascular aortic repair (EVAR) has gained wide acceptance for the elective treatment of abdominal aortic aneurysms (AAA), leading to interest in similar treatment of ruptured abdominal aortic aneurysms (RAAA). The purpose of this study was to evaluate national outcomes after EVAR for RAAA and to assess the effect of institutional volume metrics. METHODS: The Nationwide Inpatient Sample was used to identify patients treated with open or EVAR for RAAA, 2001-2006. Procedure volume was determined for each institution categorizing hospitals as low-, medium-, and high-volume. The primary outcome was in-hospital mortality. Secondary outcomes related to resource utilization. Multivariable logistic regression models were used to determine independent predictors of EVAR usage and mortality. RESULTS: From 2001 to 2006, an estimated 27,750 hospital discharges for RAAA occurred; 11.5% were treated with EVAR. EVAR utilization increased over time (5.9% in 2001 to 18.9% in 2006, P < .0001) while overall RAAA rates remained constant. EVAR had a lower overall in-hospital mortality than open repair (31.7% vs 40.7%, P < .0001), an effect which amplified when stratified by institutional volume. On multivariable regression, open repair independently predicted mortality (odds ratio [OR] 1.56; 95% confidence interval [CI] 1.29-1.89). EVAR usage for RAAA increased with age (>80 years) (OR 1.58; 95% CI 1.30-1.93), high elective EVAR volume (>40/y) vs medium (19-40/y) (OR 2.65; 95% CI 1.86-3.78) and low (<19/y) (OR 5.37; 95% CI 3.60-8.0). EVAR had a shorter length of stay (11.1 vs 13.8 days, P < .0001), higher discharges to home (65.1% vs 53.9%, P < .0001), and lower charges ($108,672 vs $114,784, P < .0001). CONCLUSIONS: In the United States, for RAAA, EVAR had a lower postoperative mortality than open repair. Higher elective open repair as well as RAAA volume increased this mortality advantage for EVAR. These results support regionalization of RAAA repair to high volume centers whenever possible and a wider adoption of endovascular repair of RAAA nationwide.

Hand-assisted laparoscopic aortobifemoral bypass versus open bypass for occlusive disease.

BACKGROUND: Aortobifemoral bypass grafting is the treatment of choice for patients with symptomatic aortoiliac occlusive disease. Yet, traditional operative exposure through a midline laparotomy incision carries significant morbidity. The authors compare operative and patient outcomes following hand-assisted laparoscopic aortobifemoral (HALABF) bypass and open aortobifemoral (OABF) bypass. METHODS: An initial series of patients who underwent HALABF bypass grafting (n = 8) were compared with a simultaneous cohort of patients treated with standard open bypass (n = 10). The two groups were similar with respect to age, weight, and sex. Operative parameters, clinical outcomes, and complications were compared. RESULTS: HALABF was successfully performed in all eight cases attempted. Operative times did not differ between the laparoscopic and open groups (234 +/- 42 minutes vs. 206 +/- 43 minutes, P =.99). Mean blood loss values were comparable (562 mL [HALABF] vs. 756 mL [OABF], P =.56). There were no conversions. Time to resumption of oral intake (1.8 vs. 4.7 days, P =.001) and length of stay (3.8 vs. 6.3 days, P =.0004) were significantly shorter in the laparoscopic than in the open group. CONCLUSIONS: HALABF is a safe and technically feasible procedure. When compared with the traditional open operation, this technique may result in shorter hospitalization, more rapid return of bowel function, and earlier return to activity.