Variation in Ultrasound Diagnostic Thresholds for Carotid Stenosis in the United States.

BACKGROUND: Individuals with carotid stenosis enter surveillance or are considered for surgery on the basis of disease severity assessed by ultrasound. However, there is variation in the ultrasound diagnostic thresholds used to determine disease severity. Our objective was to describe this variation and its potential impact on patients. METHODS: To describe the variation in carotid ultrasound diagnostic thresholds, we examined testing protocols from 338 accredited vascular testing centers in the United States. To determine the potential impact of this variation, we applied the range of thresholds to carotid ultrasound parameters from 2 groups: a population-based sample ≥65 years of age in the Cardiovascular Health Study (n=4791), and a cohort of patients who underwent surgery for asymptomatic carotid stenosis in the Vascular Quality Initiative registry (n=28 483). RESULTS: Internal carotid artery peak systolic velocity was used by all centers to assess disease severity, with 60 distinct thresholds in use. The peak systolic velocity threshold for moderate (≥50%) stenosis ranged from 110 to 245 cm/s (median, 125; 5th and 95th percentile, 125 and 150), and the threshold for severe (≥70%) stenosis ranged from 175 to 340 cm/s (median, 230; 5th and 95th percentile, 230 and 275). In the population-based sample, the 5th percentile threshold would assign a diagnosis of moderate carotid stenosis to twice as many individuals as the 95th percentile threshold (7.9% versus 3.9%; relative risk, 2.01 [CI, 1.70-2.38]). In the surgical cohort, 1 in 10 (9.8%) patients had peak systolic velocity values that warranted the diagnosis of severe carotid stenosis at centers in the 5th percentile, but not in the 95th. CONCLUSIONS: The diagnostic threshold for carotid stenosis varies considerably. Whether or not a person is said to have moderate stenosis and enters surveillance, and whether or not they have severe stenosis and are candidates for surgery, can depend on which center performs their ultrasound.

Computed tomography angiography-derived area stenosis calculations overestimate degree of carotid stenosis compared with North American Symptomatic Carotid Endarterectomy Trial-derived diameter stenosis calculations.

OBJECTIVE: The degree of carotid artery stenosis, calculated using catheter-based angiography and the North American Symptomatic Carotid Endarterectomy Trial (NASCET) method, has been shown to predict the stroke risk in several, large, randomized controlled trials. In the present era, patients have been increasingly evaluated using computed tomography (CT) angiography (CTA) before carotid artery revascularization, especially as the use of transcarotid artery revascularization has increased. Interpretation of CTA findings regarding the degree of carotid stenosis has not been standardized, with both NASCET methods and the area stenosis used. We performed a single-institution, blinded, retrospective analysis of CTA studies using both the NASCET method and the CT-derived area stenosis to assess the concordance and discordance between the two methods when evaluating ≥70% and ≥80% stenosis. METHODS: The UMass Memorial Medical Center vascular laboratory database was queried for all carotid duplex ultrasound scans performed from 2008 to 2017. The included patients were limited to those with duplex-defined ≥70% stenosis (defined as a peak systolic velocity of ≥125 cm/s and an internal carotid artery/common carotid artery ratio of ≥4), and a correlative CTA study performed within 1 year of the duplex ultrasound examination. A blinded review of all correlative CTA studies using centerline measurements on a three-dimensional workstation (Aquarius iNtuition Viewer; Terarecon, Durham, NC) was performed to characterize the degree of carotid stenosis using the NASCET method and the area stenosis method. Patients were excluded if revascularization had been performed between the two imaging studies. RESULTS: Of the 37,204 carotid duplex ultrasound scans reviewed (performed from 2008 to 2017), 3480 arteries met the criteria for duplex ultrasound-defined ≥70% stenosis. A correlative CTA study within 1 year of the duplex ultrasound examination was identified in 460 arteries, of which 320 were adequate quality for blinded review. The median interval between the duplex ultrasound and CTA examinations was 9.5 days. Concordance between the area stenosis and NASCET methods was poor for both ≥70% (κ = 0.32) and ≥80% (κ = 0.25) stenosis. Of the 247 arteries considered to have ≥70% area stenosis, 127 (51.4%) were considered to have ≥70% stenosis using the NASCET method. Of the 169 arteries considered to have ≥80% area stenosis, 44 (26.0%) were considered to have ≥80% stenosis using the NASCET method. CONCLUSIONS: The area stenosis CTA calculations of carotid artery stenosis dramatically overestimated the degree of carotid stenosis compared with that calculated using the NASCET method. Given that stroke risk estimates have been determined from trials that used the NASCET method, the area stenosis method likely overestimates the risk of stroke. Therefore, area stenosis calculations could lead to unnecessary carotid revascularization procedures. This model highlights the need for standardized usage of the NASCET method when using CTA as the imaging modality to determine the threshold for carotid revascularization.

Preoperative functional status predicts 2-year mortality in patients undergoing fenestrated/branched endovascular aneurysm repair.

BACKGROUND: Fenestrated/branched endovascular aneurysm repair (F/BEVAR) is a minimally invasive alternative for patients at high risk of open repair of complex aortic aneurysms. Nearly all investigative study protocols evaluating F/BEVAR have required a predicted life expectancy of >2 years for study inclusion. However, accurate risk models for predicting 2-year survival in this patient population are lacking. We sought to identify the preoperative predictors of 2-year survival for patients undergoing F/BEVAR. METHODS: The prospectively collected data for all consecutive F/BEVAR procedures, performed in an institutional review board-approved registry and/or a physician-sponsored investigational device exemption (IDE) trial (IDE no. G130210), were reviewed (November 2010 to February 2019). We assessed 44 preoperative patient characteristics, including comorbidities, preoperative functional status, aneurysm morphologies, and repair techniques. Preoperative functional status was defined as totally dependent (any impairment in activities of daily living or residing in a skilled nursing facility), partially dependent (any impairment in instrumental activities of daily living), or independent (no impairment in activities of daily living or instrumental activities of daily living). Using the results of univariate analysis (P < .2), a Cox proportional hazards model was constructed to identify the independent predictors of 2-year all-cause mortality. RESULTS: For the 256 consecutive patients who had undergone F/BEVAR (6 common iliac [2.3%], 94 juxtarenal [41%], 35 pararenal [14%], 119 thoracoabdominal [47%], and 2 arch [0.8%] aneurysms), the 2-year mortality was 18%. On Cox modeling, the only independent preoperative predictor contributing to 2-year mortality was functional status (totally dependent: hazard ratio [HR], 5.4; 95% confidence interval [CI], 1.8-16; P = .0024; partially dependent: HR, 4.5; 95% CI, 2.4-8.7; P < .0000019). A history of an implanted anti-arrhythmic device was protective (HR, 0.4; 95% CI, 0.2-0.99; P = .0495). Factors such as age, congestive heart failure, chronic kidney disease, diabetes, chronic obstructive pulmonary disease, aneurysm extent, and previous aortic surgery, were not significant. The 2-year mortality for the independent (n = 176; 69%), partially dependent (n = 69; 27%), and totally dependent (n = 10; 3.9%) groups was 11%, 33%, and 40%, respectively. CONCLUSIONS: For patients undergoing F/BEVAR, decreased preoperative functional status was the strongest predictor of 2-year mortality, with totally dependent patients experiencing poor survival. The traditional risk factors were not independently significant, perhaps reflecting the high prevalence of severe chronic illness in these high-risk patients participating in an IDE trial. For the independent patients, the 2-year F/BEVAR survival rate was 89%, equivalent to patient survival after infrarenal EVAR. Therefore, for independent patients, it would be reasonable to expand the indication for F/BEVAR to low-risk patients.

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.

Effect of thoracoabdominal aortic aneurysm extent on outcomes in patients undergoing fenestrated/branched endovascular aneurysm repair.

OBJECTIVE: The outcomes after open repair of thoracoabdominal aneurysms (TAAAs) have been definitively demonstrated to worsen as the TAAA extent increases. However, the effect of TAAA extent on fenestrated/branched endovascular aneurysm repair (F/BEVAR) outcomes is unclear. We investigated the differences in outcomes of F/BEVAR according to the TAAA extent. METHODS: We reviewed a single-institution, prospectively maintained database of all F/BEVAR procedures performed in an institutional review board-approved registry and/or physician-sponsored Food and Drug Administration investigational device exemption trial (trial no. G130210). The patients were stratified into two groups: group 1, extensive (extent 1-3) TAAAs; and group 2, nonextensive (juxtarenal, pararenal, and extent 4-5) TAAAs. The perioperative outcomes were compared using the χ2 test. Kaplan-Meier analysis of 3-year survival, target artery patency, reintervention, type I or III endoleak, and branch instability (type Ic or III endoleak, loss of branch patency, target vessel stenosis >50%) was performed. Cox proportional hazards modeling was used to assess the independent effect of extensive TAAA on 1-year mortality. RESULTS: During the study period, 299 F/BEVAR procedures were performed for 87 extensive TAAAs (29%) and 212 nonextensive TAAAs (71%). Most repairs had used company-manufactured, custom-made devices (n = 241; 81%). Between the two groups, no perioperative differences were observed in myocardial infarction, stroke, acute kidney injury, dialysis, target artery occlusion, access site complication, or type I or III endoleak (P > .05 for all). The incidence of perioperative paraparesis was greater in the extensive TAAA group (8.1% vs 0.5%; P = .001). However, the incidence of long-term paralysis was equivalent (2.3% vs 0.5%; P = .20), with nearly all patients with paraparesis regaining ambulatory function. On Kaplan-Meier analysis, no differences in survival, target artery patency, or freedom from reintervention were observed at 3 years (P > .05 for all). Freedom from type I or III endoleak (P < .01) and freedom from branch instability (P < .01) were significantly worse in the extensive TAAA group. Cox proportional hazards modeling demonstrated that F/BEVAR for extensive TAAA was not associated with 1-year mortality (hazard ratio, 1.71; 95% confidence interval, 0.91-3.52; P = .13). CONCLUSIONS: Unlike open TAAA repair, the F/BEVAR outcomes were similar for extensive and nonextensive TAAAs. The differences in perioperative paraparesis, branch instability, and type I or III endoleak likely resulted from the increasing length of aortic coverage and number of target arteries involved. These findings suggest that high-volume centers performing F/BEVAR should expect comparable outcomes for extensive and nonextensive TAAA repair.

Financial implications of coronavirus disease 2019 on a tertiary academic vascular surgery practice.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has had an unprecedented impact on the healthcare system in the United States. The redistribution of resources and suspension of elective procedures and other services has resulted in financial stress across all service lines. The financial effects on the practice of vascular surgery have not yet been quantified. We hypothesized that vascular surgery divisions have experienced losses affecting the hospital and professional sides that will not be recoupable without significant productivity increases. METHODS: Administrative claims data for clinical services performed by the vascular surgery division at a tertiary medical center for March and April 2019 and for March and April 2020 were analyzed. These claims were separated into two categories: hospital claims (inpatient and outpatient) and professional claims (professional reimbursement for all services provided). Medicare reimbursement methods were used to assign financial value: diagnosis-related group for inpatient services, ambulatory payment classification for outpatient services, and the Medicare physician fee schedule for professional reimbursement and work relative value units (wRVUs). Reimbursements and productivity (wRVUs) were compared between the two periods. A financial model was created to determine the increase in future productivity over baseline required to mitigate the losses incurred during the pandemic. RESULTS: A total of 11,317 vascular surgery claims were reviewed. Hospital reimbursement during the pandemic decreased from $4,982,114 to $2,649,521 (-47%) overall (inpatient, from $3,505,775 to $2,128,133 [-39%]; outpatient, from $1,476,339 to $521,388 [-65%]) and professional reimbursement decreased from $933,897 to $430,967 (-54%) compared with the same period in 2019. Professional productivity as measured by wRVUs sustained a similar decline from 10,478 wRVUs to 5386 wRVUs (-51%). Modeling sensitivity analyses demonstrated that if a vascular division were able to increase inpatient and outpatient revenue to greater than prepandemic levels by 10%, 5%, or 3%, it would take 9, 19, or 31 months, respectively, for the hospital to recover their pandemic-associated losses. Similarly, professional reimbursement recovery would require 11, 20, or 36 months with corresponding increases in productivity. CONCLUSIONS: The COVID-19 pandemic has had profound and lasting effects on the world in terms of lives lost and financial hardships. The financial effects on vascular surgery divisions has resulted in losses ranging from 39% to 65% compared with the prepandemic period in the previous year. Because the complete mitigation of losses is not feasible in the short term, alternative and novel strategies are needed to financially sustain the vascular division and hospital during a prolonged recovery period.

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.

Fenestrated/Branched Endovascular Aortic Aneurysm Repair Using a Supraceliac Aortic Proximal Seal Zone Versus an Infraceliac Aortic Proximal Seal Zone.

BACKGROUND: Fenestrated/branched endovascular aneurysm repair (F/B-EVAR) achieves more extensive proximal seal than conventional infrarenal devices, thereby increasing aneurysm exclusion durability. Optimal seal zone length remains undefined. We assessed relative risks and benefits of extending the proximal seal above the celiac artery. METHODS: The prospective database of all complex endovascular aortic aneurysm repairs at a single institution (institutional review board-approved, physician-sponsored investigational device exemption trial, 10/2010-6/2017) was used to classify repairs according to the number of target visceral-renal arteries incorporated: 4-vessel versus <4-vessel. Comparisons of aneurysm characteristics, perioperative details, and postoperative complications were performed, stratified by repair type. One-year survival, target artery patency, freedom from type 1 or 3 endoleak, and freedom from reintervention were estimated with Kaplan-Meier analysis. RESULTS: Among 175 F/B-EVARs, 38% (n = 67) were 4-vessel and 62% (n = 108) were <4-vessel. Intraoperatively, there was no difference in mean contrast use (76 mL vs. 74 mL, P = non significant [NS]) or dose area product (63,428 mGy cm2 vs. 96,015 mGy cm2), but there was increased median procedure time (4.8 hr, interquartile range [IQR] = 4.1-5.8 versus 3.6 hr, IQR = 2.9-4.1, P < 0.0001) and mean operating room direct costs ($52,532, standard deviation [SD] = 18,640 versus $40,128, SD = 15,135, P < 0.0001) in 4-vessel repairs. There were no differences in mortality (1.9% vs. 4.5%), paraparesis (0% vs. 3.0%), or paralysis (0.9% vs. 0%), all P = NS. There were no differences in one-year survival, target artery patency, or freedom from reintervention. There was a lower 1-year freedom from type 1 or 3 endoleak with 4-vessel repairs (82% vs. 94%, log-rank P = 0.02), driven by an increased rate of type 3 endoleaks. Endoleak resolution after treatment was equivalent in both groups (4-vessel, 10 of 12, 83% resolved; <4-vessel, 7 of 7, 100% resolved, P = NS). CONCLUSIONS: With F/B-EVAR, utilization of a supraceliac seal zone, compared with an infraceliac seal zone, is associated with statistical differences in operative characteristics/resource utilization, but with negligible clinical significance. Further innovation to eliminate type 3 endoleaks at fenestrations/branches remains an unmet need. To achieve adequate F/B-EVAR proximal seal zone length, one should have a low threshold to incorporate the celiac artery.

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.

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.

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.

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.

Complete regression of a symptomatic, mycotic juxtarenal abdominal aortic aneurysm after treatment with fenestrated endovascular aneurysm repair.

Mycotic abdominal aortic aneurysms are rare and present unique challenges when potential treatment options are considered. Although aortic resection with in situ grafting techniques or extra-anatomic reconstruction are the treatments of choice, endovascular aortic repair has emerged as a suitable alternative in critically ill patients. We report the successful endovascular repair of a symptomatic, mycotic juxtarenal aortic aneurysm using a physician-modified fenestrated endograft. In this patient, with >6 months of follow-up, the aneurysm has completely regressed, illustrating that in select patients with complex mycotic aneurysms, endovascular repair combined with appropriate medical management is a viable treatment strategy.

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.

Treating Chronic Iliac Vein Stent Occlusion in an Office-Based Lab Setting.

Iliac vein stenting is performed when sufficient venous patency is not achieved via angioplasty or lysis. Iliac vein stenting is known to be effective; however, occlusion of the stent occurs occasionally. There is a lack of effective treatment options for those with failed prior venous stents, and traditional methods may involve the removal of the stent and surgical reconstruction. We present a patient with a right leg post-thrombotic syndrome and narcotic abuse after occlusion of a previously placed right common iliac/external iliac vein stent 25 years prior. After transfer to an office-based lab (OBL), femoral vein access was achieved. Then, a second stent was deployed adjacent to the previously chronically thrombosed stent. Imaging confirmed adequate deployment of the new stent and venous flow. Treatment resulted in a significant decrease in patient pain and cessation of narcotics. We demonstrate successful recanalization of a right iliac vein thrombosis via parallel deployment of a stent adjacent to a chronically thrombosed stent.

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.