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

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\u27s diagnostic criteria and the costs of these procedures based on reimbursement rates. Among 10614 patients who underwent 15534 carotid duplex scans, 31025 arteries were reviewed. Application of the 10 institutions\u27 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

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 \u3c .0001) while overall RAAA rates remained constant. EVAR had a lower overall in-hospital mortality than open repair (31.7% vs 40.7%, P \u3c .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 (\u3e80 years) (OR 1.58; 95% CI 1.30-1.93), high elective EVAR volume (\u3e40/y) vs medium (19-40/y) (OR 2.65; 95% CI 1.86-3.78) and low (\u3c19/y) (OR 5.37; 95% CI 3.60-8.0). EVAR had a shorter length of stay (11.1 vs 13.8 days, P \u3c .0001), higher discharges to home (65.1% vs 53.9%, P \u3c .0001), and lower charges ($108,672 vs$114,784, P \u3c .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

An increasing demand for integrated vascular residency training far outweighs the limited supply of positions

OBJECTIVE: The integrated vascular surgery residency training paradigm ( 0 + 5 ) was first approved by the Accreditation Council for Graduate Medical Education (ACGME) in 2006, with the first residents beginning in 2007. We sought to evaluate the demand for these new positions and to better understand applicant pool demographics. METHOD: The Association of American Medical Colleges (AAMC) was petitioned for data on applicants to traditional vascular surgery fellowship and integrated vascular residency training programs (years 2006-2009). In addition, 111 applications received at a single academic institution for the year 2009 were reviewed in depth. RESULT: The number of traditional vascular fellowship applicants and the corresponding number of positions remained stable. In contrast, the number of integrated vascular resident applicants increased dramatically, with 152 applicants seeking to match into 19 available positions in 2009. For the year 2009, 88% of integrated vascular residency applicants did not match, while 16% of traditional fellowship positions went unfilled. The most notable difference between integrated residency and traditional fellowship applicants is the number of foreign medical graduates (68.7% vs. 26.7% in 2008, P \u3c .001). Of the 111 integrated applicants applying for our single position (73% of entire 2009 applicant pool), the majority of applicants were residing in the United States (88.3%) and a sizable proportion (25.2%) had completed at least one full year of either surgical training or surgical research at an institution in the Unites States. Objective measures of academic success included mean United States Medical Licensing Examination (USMLE) Step 1 and Step 2 scores of 89.1 and 89.5, respectively. The mean number of peer-reviewed journal publications at the time of application was 2.8. CONCLUSION: The number of integrated vascular surgery residency applicants far outweighs the number of available positions. Growing interest in more efficient and comprehensive vascular surgery training will continue to augment demand. As educators, vascular surgeons should seize this opportunity and aggressively expand the number of available integrated residency training positions

An analysis of carotid artery stenting procedures performed in New York and Florida (2005-2006): procedure indication, stroke rate, and mortality rate are equivalent for vascular surgeons and non-vascular surgeons

OBJECTIVE: Carotid artery stenting (CAS) has emerged as an alternative to carotid endarterectomy (CEA) for the treatment of carotid artery stenosis. Unlike CEA, CAS is performed by a wide variety of specialists including vascular surgeons (VS), interventional cardiologists (IC), and interventional radiologists (IR). This study compares the indications, in-patient mortality rate, and in-patient stroke rate for patients undergoing CAS, according to operator specialty. METHODS: The State In-patient Databases from New York and Florida, made available by the Healthcare Cost and Utilization Project, were reviewed by International Classification of Disease (ICD)-9-CM codes to identify all patients treated with CAS for the years 2005 and 2006. This cohort was then stratified according to operator specialty defined by procedures performed by each operator over the years surveyed. Primary endpoints were in-patient death and stroke. Propensity score matching adjusting for indication, demographics, and comorbidities was employed to evaluate the influence of operator type on outcomes. RESULTS: During the study period, 4001 CAS procedures were performed. All primary analyses compared VS (n = 1350) to non-VS (n = 2651). Patient characteristics were similar, except VS treated fewer patients with CAD (44.2% vs 50.9%, P \u3c .001) and valvular disease (6.3% vs 8.6%, P = .01) and more patients with chronic lung disease (19.4% vs 15.9%, P = .01). Each group performed an equal proportion of CAS for symptomatic disease (8.1% vs 9.0%, P = .32). Univariate analysis revealed no difference in mortality (0.9% vs 0.5%, P = .13) or stroke (1.3% vs 1.5%, P = .73). Propensity score matched analysis also demonstrated no difference in mortality (0.7% vs 0.4%, P = .48) or stroke (1.1% vs 1.7%, P = .27). Subgroup analysis comparing VS, IC, and IR showed no significant difference in mortality or stroke, but demonstrated that of the three specialties, IC treated the smallest proportion of symptomatic patients. The proportion of CAS performed by VS differed significantly by state (New York 46%, Florida 19%, P \u3c .01). CONCLUSION: Despite a paucity of level 1 evidence for CAS in asymptomatic patients and current Centers for Medicare and Medicaid Services (CMS) policy limiting reimbursement for CAS to only high-risk symptomatic patients, VS and non-VS are treating primarily asymptomatic patients. Perioperative rates of stroke and death are equivalent between VS, IC, and IR. Regional variation of operator type is substantial, and despite similar outcomes, \u3c50% of CAS is performed by VS

Vascular surgery training trends from 2001-2007: A substantial increase in total procedure volume is driven by escalating endovascular procedure volume and stable open procedure volume

BACKGROUND: Endovascular procedure volume has increased rapidly, and endovascular procedures have become the initial treatment option for many vascular diseases. Consequently, training in endovascular procedures has become an essential component of vascular surgery training. We hypothesized that, due to this paradigm shift, open surgical case volume may have declined, thereby jeopardizing training and technical skill acquisition in open procedures. METHODS: Vascular surgery trainees are required to log both open and endovascular procedures with the Accreditation Council for Graduate Medical Education (ACGME). We analyzed the ACGME database (2001-2007), which records all cases (by Current Procedural Terminology [CPT] code) performed by graduating vascular trainees. Case volume was evaluated according to the mean number of cases performed per graduating trainee. RESULTS: The mean number of total major vascular procedures performed per trainee increased by 174% between 2001 and 2007 (from 298.3 to 519.2). Endovascular diagnostic and therapeutic procedures increased by 422% (from 63.7 to 269.1) and accounted for 93.0% of the increase in total procedures. The number of open aortic procedures (aneurysm, occlusive, mesenteric, renal) decreased by 17.1% (from 49.7 to 41.2), while the number of endovascular aortic aneurysm repair procedures increased by 298.8% (from 16.9 to 50.5). Specifically, open aortic aneurysm procedures decreased by 21.8%, aortobifemoral bypass increased by 3.2%, and open mesenteric or renal procedures decreased by 13%. Infrainguinal bypass procedures remained relatively constant (from 37.6 to 36.5, 2.9% decrease), and the number of carotid endarterectomy procedures performed did not change significantly (from 43.6 to 42.2, 3.2% decrease). CONCLUSION: Vascular surgery trainees are performing a vastly increased total number of procedures. This increase in total procedure volume is almost entirely attributable to the recent increase in endovascular procedures. Aside from a small decline in open aortic procedures, the volume of open surgical procedures has largely remained stable. It is essential that vascular surgery training programs continue to focus on both endovascular and open surgical skills in order for vascular surgeons to remain the premier specialists to care for patients with vascular disease

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 \u3c7, medium 7-30, and high \u3e30) and surgeon volume (low ≤2, medium 3-9, and high \u3e9). 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 \u3c .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 \u3c .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. All rights reserved