Volumetric Analysis of Acute Uncomplicated Type B Aortic Dissection Using an Automated Deep Learning Aortic Zone Segmentation Model.

INTRODUCTION: Machine learning techniques have shown excellent performance in 3D medical image analysis, but have not been applied to acute uncomplicated type B aortic dissection (auTBAD) utilizing SVS/STS-defined aortic zones. The purpose of this study was to establish a trained, automatic machine learning aortic zone segmentation model to facilitate performance of an aortic zone volumetric comparison between auTBAD patients based on rate of aortic growth. METHODS: Patients with auTBAD and serial imaging were identified. For each patient, imaging characteristics from two CT scans were analyzed: (1) the baseline CTA at index admission, and (2) either the most recent surveillance CTA, or the most recent CTA prior to an aortic intervention. Patients were stratified into two comparative groups based on aortic growth: rapid growth (diameter increase ≥5mm/year) and no/slow growth (diameter increase <5mm/year). Deidentified images were imported into an open-source software package for medical image analysis and images were annotated based on SVS/STS criteria for aortic zones. Our model was trained using 4-fold cross-validation. The segmentation output was used to calculate aortic zone volumes from each imaging study. RESULTS: Of 59 patients identified for inclusion, rapid growth was observed in 33 (56%) patients and no/slow growth was observed in 26 (44%) patients. There were no differences in baseline demographics, comorbidities, admission mean arterial pressure, number of discharge antihypertensives, or high-risk imaging characteristics between groups (p>0.05 for all). Median duration between baseline and interval CT was 1.07 years (IQR 0.38-2.57). Post-discharge aortic intervention was performed in 13 (22%) of patients at a mean of 1.5±1.2 years, with no difference between groups (p>0.05). Among all patients, the largest relative percent increases in zone volumes over time were found in zone 4 (13.9% IQR -6.82-35.1) and zone 5 (13.4% IQR -7.78-37.9). There were no differences in baseline zone volumes between groups (p>0.05 for all). Average Dice coefficient, a performance measure of the model output, was 0.73. Performance was best in zone 5 (0.84) and zone 9 (0.91). CONCLUSIONS: We describe an automatic deep learning segmentation model incorporating SVS-defined aortic zones. The open-source, trained model demonstrates concordance to the manually segmented aortas with the strongest performance in zones 5 and 9, providing a framework for further clinical applications. In our limited sample, there were no differences in baseline aortic zone volumes between rapid growth and no/slow growth patients.

Comparative outcomes of open mesenteric bypass after a failed endovascular or open mesenteric revascularization for chronic mesenteric ischemia.

INTRODUCTION: Clinical practice guidelines have recommended an endovascular-first approach (ENDO) for the management of patients with chronic mesenteric ischemia (CMI), whereas an open mesenteric bypass (OMB) is proposed for subjects deemed to be poor ENDO candidates. However, the impact of a previous failed endovascular or open mesenteric reconstruction on a subsequent OMB is unknown. Accordingly, this study was designed to examine the results of a remedial OMB (R-OMB) after a failed ENDO or a primary OMB (P-OMB) for patients with recurrent CMI. METHODS: All patients who underwent an OMB from 2002 to 2022 at the University of Florida were reviewed. Outcomes after an R-OMB (ie, history of a failed ENDO or P-OMB) and P-OMB were compared. The primary end point was 30-day mortality, whereas secondary outcomes included complications, reintervention, and survival. The Kaplan-Meier methodology was used to estimate freedom from reintervention and all-cause mortality, whereas multivariable Cox proportional hazards modeling identified predictors of death. RESULTS: A total of 145 OMB procedures (R-OMB, n = 48 [33%]; P-OMB, n = 97 [67%]) were analyzed. A majority of R-OMB operations were performed for a failed stent (prior ENDO, n = 39 [81%]; prior OMB, n = 9 [19%]). R-OMB patients were generally younger (66 ± 9 years vs P-OMB, 69 ± 11 years; P = .09) and had lower incidence of smoking exposure (29% vs P-OMB, 48%; P = .07); however, there were no other differences in demographics or comorbidities. R-OMB was associated with less intraoperative transfusion (0.6 units vs P-OMB, 1.4 units; P = .01), but there were no differences in conduit choice or bypass configuration.The overall 30-day mortality and complication rates were 7% (n = 10/145) and 53% (n = 77/145), respectively, with no difference between the groups. Notably, R-OMB had decreased cardiac (6% vs P-OMB, 21%; P < .01) and bleeding complication rates (2% vs P-OMB, 15%; P = .01). The freedom from reintervention (1 and 5 years: R-OMB: 95% ± 4%, 83% ± 9% vs P-OMB: 97% ± 2%, 93% ± 5%, respectively; log-rank P = .21) and survival (1 and 5 years: R-OMB: 82% ± 6%, 68% ± 9% vs P-OMB: 84% ± 4%, 66% ± 7%; P = .91) were similar. Independent predictors of all-cause mortality included new postoperative hemodialysis requirement (hazard ratio [HR], 7.4, 95% confidence interval [CI], 3.1-17.3; P < .001), pulmonary (HR, 2.7, 95% CI, 1.4-5.3; P = .004) and cardiac (HR, 2.4, 95% CI, 1.1-5.1; P = .04) complications, and female sex (HR, 2.1, 95% CI, 1.03-4.8; P = .04). Notably, R-OMB was not a predictor of death. CONCLUSIONS: The perioperative and longer-term outcomes for a remedial OMB after a failed intraluminal stent or previous open bypass appear to be comparable to a P-OMB. These findings support the recently updated clinical practice guideline recommendations for an endovascular-first approach to treating recurrent CMI due to the significant perioperative complication risk of OMB. However, among the subset of patients deemed ineligible for endoluminal reconstruction after failed mesenteric revascularization, R-OMB results appear to be acceptable and highlight the utility of this strategy in selected patients.

Outcomes of Patients with Acute Type B Aortic Dissection and High-Risk Features.

BACKGROUND: Recently the Society for Vascular Surgery (SVS) and Society for Thoracic Surgeons (STS) published contemporary guidelines clearly defining complicated versus uncomplicated acute type B aortic dissections (TBADs) with an additional high-risk grouping. Few studies have evaluated outcomes associated with "high-risk" TBADs. The objective of this study was to assess differences in demographics, clinical presentation, symptom onset, and outcomes in high-risk patients that underwent either thoracic endovascular aortic repair (TEVAR) or best medical management for acute TBAD compared to those with complicated and uncomplicated acute TBAD. METHODS: Patients admitted with acute TBADs from a single academic medical center from October 2011 to March 2020 were analyzed. Per the STS/SVS 2020 guidelines, high risk was defined as refractory pain/hypertension, bloody pleural effusion, aortic diameter >4 cm, false lumen diameter >22 mm, radiographic malperfusion, and early readmission, and complicated was defined as ruptured/malperfusion presentation. Uncomplicated patients were those without malperfusion/rupture and without high-risk features. The primary end-point was inpatient mortality. Secondary end-points included complications, reintervention, and survival. RESULTS: Of the 159 patients identified with acute TBAD, 63 (40%) met the high-risk criteria. In the high-risk cohort, 38 (60%) underwent TEVAR (HR-TEVAR), with refractory pain as the most common indication, while 25 (40%) were managed medically (HR-medical). Malperfusion or rupture was present in 63 (40%) patients (complicated TBAD (C-TBAD)), all of whom underwent TEVAR. An additional 33 patients had no high-risk features and were all managed medically (uncomplicated TBAD). There were no differences in age, body mass index, and race between groups. Among the 4 groups, there were variable distributions in sex, insurance status, and incidence of several baseline comorbidities including congestive heart failure, chronic obstructive pulmonary disease, and renal dysfunction (P < 0.05 for all). C-TBAD had increased length of stay (12, interquartile range [IQR] 9-22) compared to HR-TEVAR (11.5, IQR 7-15), HR-medical (6, IQR 5-8), and uncomplicated TBAD (7, IQR 5-10) (P < 0.01). C-TBAD had decreased days from admission to repair (0, IQR 0-2) compared to HR-TEVAR (3.5, IQR 1-8) (P < 0.01). C-TBAD patients had worse 3-year survival compared to other groups (log-rank P < 0.01), although when in-hospital mortality was excluded, survival was similar among groups (P = 0.37). Of patients initially managed medically, outpatient TEVAR was performed in 6 (24%) HR-medical and 4 (12%) uncomplicated patients, with no difference between rate of intervention between groups (P = 0.22). CONCLUSIONS: High-risk features, as defined in updated SVS/STS guidelines, are common in patients presenting with acute TBAD. High-risk patients had acceptable outcomes when managed either surgically or medically. High-risk patients that underwent TEVAR had improved perioperative outcomes and mortality compared to those undergoing TEVAR for C-TBAD, a finding which may help guide preoperative risk stratification and patient counseling.

Persistent Acute Kidney Injury is Associated with Poor Outcomes and Increased Hospital Cost in Vascular Surgery.

BACKGROUND: Postoperative acute kidney injury (AKI) is common after major surgery and is associated with increased morbidity, mortality, and cost. Additionally, there are recent studies demonstrating that time to renal recovery may have a substantial impact on clinical outcomes. We hypothesized that patients with delayed renal recovery after major vascular surgery will have increased complications, mortality, and hospital cost. METHODS: A single-center retrospective cohort of patients undergoing nonemergent major vascular surgery between 6/1/2014 and 10/1/2020 was analyzed. Development of postoperative AKI (defined using Kidney Disease Improving Global Outcomes (KDIGO) criteria: >50% or > 0.3 mg/dl absolute increase in serum creatinine relative to reference after surgery and before discharge) was evaluated. Patients were divided into 3 groups: no AKI, rapidly reversed AKI (<48 hours), and persistent AKI (≥48 hours). Multivariable generalized linear models were used to evaluate the association between AKI groups and postoperative complications, 90-day mortality, and hospital cost. RESULTS: A total of 1,881 patients undergoing 1,980 vascular procedures were included. Thirty five percent of patients developed postoperative AKI. Patients with persistent AKI had longer intensive care unit and hospital stays, as well as more mechanical ventilation days. In multivariable logistic regression analysis, persistent AKI was a major predictor of 90-day mortality (odds ratio 4.1, 95% confidence interval 2.4-7.1). Adjusted average cost was higher for patients with any type of AKI. The incremental cost of having any AKI ranged from $3,700 to $9,100, even after adjustment for comorbidities and other postoperative complications. The adjusted average cost for patients stratified by type of AKI was higher among patients with persistent AKI compared to those with no or rapidly reversed AKI. CONCLUSIONS: Persistent AKI after vascular surgery is associated with increased complications, mortality, and cost. Strategies to prevent and aggressively treat AKI, specifically persistent AKI, in the perioperative setting are imperative to optimize care for this population.

Perioperative Cerebrospinal Fluid Drain Placement Does Not Increase Venous Thromboembolism Risk After Thoracic and Fenestrated Endovascular Aortic Repair.

BACKGROUND: Venous thromboembolism (VTE) incidence after thoracic and fenestrated endovascular aortic repair (TEVAR/FEVAR) is high (up to 6-7%) relative to other vascular procedures; however, the etiology for this discrepancy remains unknown. Notably, patients undergoing TEVAR/FEVAR commonly receive cerebrospinal fluid drains (CSFDs) for neuroprotection, requiring interruption of perioperative anticoagulation and prolonged immobility. We hypothesized that CSFDs are a risk factor for VTE after TEVAR/FEVAR. METHODS: Consecutive TEVAR/FEVAR patients at a single center were reviewed (2011-2020). Cerebrospinal fluid drains (CSFDs) were placed based on surgeon preference preoperatively or for spinal cord ischemia (SCI) rescue therapy postoperatively. The primary end-point was VTE occurrence, defined as any new deep venous thrombosis (DVT) or pulmonary embolism (PE) confirmed on imaging within 30 days postoperatively. Routine postoperative VTE screening was not performed. Patients with and without VTE, and subjects with and without CSFDs were compared. Logistic regression was used to explore associations between VTE incidence and CSFD exposure. RESULTS: Eight hundred ninety-seven patients underwent TEVAR/FEVAR and 43% (n = 387) received a CSFD at some point during their care (preoperative: 94% [n = 365/387]; postoperative SCI rescue therapy: 6% [n = 22/387]). CSFD patients were more likely to have previous aortic surgery (44% vs. 37%; P = 0.028) and received more postoperative blood products (780 vs. 405 mL; P = 0.005). The overall VTE incidence was 2.2% (n = 20). 70% (14) patients with VTE had DVT, 50% (10) had PE, and 20% (4) had DVT and PE. Among TEVAR/FEVAR patients with VTE, 65% (n = 13) were symptomatic. Most VTEs (90%, n = 18) were identified inhospital and the median time to diagnosis was 12.5 (interquartile range 7.5-18) days postoperatively. Patients with VTE were more likely to have nonelective surgery (95% vs. 41%; P < 0.001), had higher American Society of Anesthesiologists classification (4.1 vs. 3.7; P < 0.001), required longer intensive care unit admission (24 vs. 12 days; P < 0.001), and received more blood products (1,386 vs. 559 mL; P < 0.001). Venous thromboembolism (VTE) incidence was 1.8% in CSFD patients compared to 3.5% in non-CSFD patients (odds ratio 0.70 [95% confidence interval 0.28-1.78, P = 0.300). However, patients receiving CSFDs postoperatively for SCI rescue therapy had significantly greater VTE incidence (9.1% vs. 1.1%; P = 0.044). CONCLUSIONS: CSFD placement was not associated with an increased risk of VTE in patients undergoing TEVAR/FEVAR. Venous thromboembolism (VTE) risk was greater in patients undergoing nonelective surgery and those with complicated perioperative courses. Venous thromboembolism (VTE) risk was greater in patients receiving therapeutic CSFDs compared to prophylactic CSFDs, highlighting the importance of careful patient selection for prophylactic CSFD placement.

Results of the North American Complex Abdominal Aortic Debranching (NACAAD) Registry.

BACKGROUND: Hybrid debranching repair of pararenal and thoracoabdominal aortic aneurysms was initially designed as a better alternative to standard open repair, addressing the limitations of endovascular repair involving the visceral aorta. We reviewed the collective outcomes of hybrid debranching repairs using extra-anatomic, open surgical debranching of the renal-mesenteric arteries, followed by endovascular aortic stenting. METHODS: Data from patients who underwent hybrid repair in 14 North American institutions during 10 years were retrospectively reviewed. Society of Vascular Surgery scores were used to assess comorbidity risk. Early and late outcomes, including mortality, morbidity, reintervention, and patency were analyzed. RESULTS: A total of 208 patients (118 male; mean age, 71±8 years old) were treated by hybrid repair with extraanatomic reconstruction of 657 renal and mesenteric arteries (mean 3.2 vessels/patient). Mean aneurysm diameter was 6.6±1.3 cm. Thoracoabdominal aortic aneurysms were identified in 163 (78%) patients and pararenal aneurysms in 45 (22%). A single-stage repair was performed in 92 (44%) patients. The iliac arteries were the most common source of inflow (n=132; 63%), and most (n=150; 72%) had 3 or more bypasses. There were 30 (14%) early deaths, ranging widely across sites (0%-21%). A Society of Vascular Surgery comorbidity score >15 was the primary predictor of early mortality (P<0.01), whereas mortality was 3% in a score ≤9. Early complications occurred in 140 (73%) patients and included respiratory complications in 45 patients (22%) and spinal cord ischemia in 22 (11%), of whom 10 (45%) fully recovered. At 5 years, survival was 61±5%, primary graft patency was 90±2%, and secondary patency was 93±2%. The most significant predictor of late mortality was renal insufficiency (P<0.0001). CONCLUSIONS: Mortality after hybrid repair and visceral debranching is highly variable by center, but strongly affected by preoperative comorbidities and the centers' experience with the technique. With excellent graft patency at 5 years, the outcomes of hybrid repair done at centers of excellence and in carefully selected patients may be comparable (or better) than traditional open or even totally endovascular approaches. However, in patients already considered as high-risk for surgery, it may not offer better outcomes.

Postoperative Overtriage to an Intensive Care Unit Is Associated With Low Value of Care.

OBJECTIVE: We test the hypothesis that for low-acuity surgical patients, postoperative intensive care unit (ICU) admission is associated with lower value of care compared with ward admission. BACKGROUND: Overtriaging low-acuity patients to ICU consumes valuable resources and may not confer better patient outcomes. Associations among postoperative overtriage, patient outcomes, costs, and value of care have not been previously reported. METHODS: In this longitudinal cohort study, postoperative ICU admissions were classified as overtriaged or appropriately triaged according to machine learning-based patient acuity assessments and requirements for immediate postoperative mechanical ventilation or vasopressor support. The nearest neighbors algorithm identified risk-matched control ward admissions. The primary outcome was value of care, calculated as inverse observed-to-expected mortality ratios divided by total costs. RESULTS: Acuity assessments had an area under the receiver operating characteristic curve of 0.92 in generating predictions for triage classifications. Of 8592 postoperative ICU admissions, 423 (4.9%) were overtriaged. These were matched with 2155 control ward admissions with similar comorbidities, incidence of emergent surgery, immediate postoperative vital signs, and do not resuscitate order placement and rescindment patterns. Compared with controls, overtraiged admissions did not have a lower incidence of any measured complications. Total costs for admission were $16.4K for overtriage and $15.9K for controls ( P =0.03). Value of care was lower for overtriaged admissions [2.9 (2.0-4.0)] compared with controls [24.2 (14.1-34.5), P <0.001]. CONCLUSIONS: Low-acuity postoperative patients who were overtriaged to ICUs had increased total costs, no improvements in outcomes, and received low-value care.

Increased Preoperative Stress Test Utilization is Not Associated With Reduced Adverse Cardiac Events in Current US Surgical Practice.

OBJECTIVE: To measure the frequency of preoperative stress testing and its association with perioperative cardiac events. BACKGROUND: There is persistent variation in preoperative stress testing across the United States. It remains unclear whether more testing is associated with reduced perioperative cardiac events. METHODS: We used the Vizient Clinical Data Base to study patients who underwent 1 of 8 elective major surgical procedures (general, vascular, or oncologic) from 2015 to 2019. We grouped centers into quintiles by frequency of stress test use. We computed a modified revised cardiac risk index (mRCRI) score for included patients. Outcomes included in-hospital major adverse cardiac events (MACEs), myocardial infarction (MI), and cost, which we compared across quintiles of stress test use. RESULTS: We identified 185,612 patients from 133 centers. The mean age was 61.7 (±14.2) years, 47.5% were female, and 79.4% were White. Stress testing was performed in 9.2% of patients undergoing surgery, and varied from 1.7% at lowest quintile centers, to 22.5% at highest quintile centers, despite similar mRCRI comorbidity scores (mRCRI>1: 15.0% vs 15.8%; P =0.068). In-hospital MACE was less frequent among lowest versus highest quintile centers (8.2% vs 9.4%; P <0.001) despite a 13-fold difference in stress test use. Event rates were similar for MI (0.5% vs 0.5%; P =0.737). Mean added cost for stress testing per 1000 patients who underwent surgery was $26,996 at lowest quintile centers versus $357,300 at highest quintile centers. CONCLUSIONS: There is substantial variation in preoperative stress testing across the United States despite similar patient risk profiles. Increased testing was not associated with reduced perioperative MACE or MI. These data suggest that more selective stress testing may be an opportunity for cost savings through a reduction of unnecessary tests.

Five-year sex-related outcomes of thoracic endovascular aortic repair in the Global Registry for Endovascular Aortic Treatment.

OBJECTIVE: The impact of sex on outcomes of thoracic endovascular aortic repair (TEVAR) represents an area of increased interest over the last decade, and long-term data are lacking. The aim of the present study was to investigate sex-related differences in long-term outcomes after TEVAR using real-world data from the Global Registry for Endovascular Aortic Treatment. METHODS: Data were obtained retrospectively after querying the multicenter, sponsored Global Registry for Endovascular Aortic Treatment. Patients treated with TEVAR between December 2010 and January 2021 were selected regardless of the type of thoracic aortic disease. The primary outcome was sex-specific all-cause mortality at 5 years and maximum follow-up. Secondary outcomes were sex-specific all-cause mortality at 30 days and 1 year, and aorta-related mortality, major adverse cardiac events, neurological complications, and device-related complications or reinterventions at 30 days, 1 year, 5 years, and maximum follow-up. RESULTS: A total of 805 patients were analyzed; 535 (66.5%) were males. Females were older (median, 66 years [interquartile range (IQR), 57-75 years] vs 69 years [IQR, 59-78 years], P < .001). Males had more frequently a history of coronary artery bypass grafting and renal insufficiency (8.7% vs 3.7% [P = .010] and 22.4% vs 11.6% [P < .001]). The median follow-up was 3.46 years (IQR, 1.49-4.99 years) for males and 3.18 years (IQR, 1.29-4.86 years) for females. Indications for TEVAR were mostly descending thoracic aortic aneurysms (n = 307 [38.1%]) type B aortic dissections (n = 250 [31.1%]) or others (n = 248 [30.8%]). Freedom from 5-year all-cause mortality was similar for males and females (67% [95% CI, 62.1-72.2] vs 65.9% [95% CI, 58.5-74.2]; P = .847), and there were no differences in secondary outcomes. Multivariable Cox regression showed females to have lower all-cause mortality rates; however, this difference did not reach statistical significance (hazard ratio, 0.97; 95% CI, 0.72-1.30; P = .834). Additional subgroup analyses based on the indication for TEVAR did not identify differences between both sexes for the primary and secondary outcomes except more endoleak type II in females with complicated type B aortic dissection (1.8% vs 12.1%; P = .023). CONCLUSIONS: The present analysis suggests that long-term outcomes of TEVAR performed irrespective of the type of aortic disease are similar for males and females. Further studies are needed to clarify existing controversies regarding the impact of sex on outcomes of TEVAR.

Assessing the quality of reporting of studies using Vascular Quality Initiative (VQI) data.

OBJECTIVE: The Society for Vascular Surgery Vascular Quality Initiative (VQI) has become an increasingly popular data source for retrospective observational vascular surgery studies. There are published guidelines on the reporting of data in such studies to promote transparency and rigor, but these have not been used to evaluate studies using VQI data. Our objective was to appraise the methodological reporting quality of studies using VQI data by evaluating their adherence to these guidelines. METHODS: The Society for Vascular Surgery VQI publication repository was queried for all articles published in 2020. The REporting of studies Conducted using Observational Routinely-collected Health Data (RECORD) statement and the Journal of American Medical Association-Surgical Section (JAMA-Surgery) checklist were utilized to assess the quality of each article's reporting. Five and three items from the RECORD statement and JAMA-Surgery checklist were excluded, respectively, because they were either inapplicable or nonassessable. Journal impact factor (IF) was queried for each article to elucidate any difference in reporting standards between high and low IF journals. RESULTS: Ninety studies were identified and analyzed. The median score on the RECORD checklist was 6 (of 8). The most commonly missed item was discussing data cleaning methods (93% missed). The median score on the JAMA-Surgery checklist was 3 (of 7). The most commonly missed items were the identification of competing risks (98% missed), the use of a flow chart to clearly define sample exclusion and inclusion criteria (84% missed), and the inclusion of a solid research question and hypothesis (81% missed). There were no differences in JAMA-Surgery checklist or RECORD statement median scores among studies published in low vs high IF journals. CONCLUSIONS: Studies using VQI data demonstrate a poor to moderate adherence to reporting standards. Key areas for improvement in research reporting include articulating a clear hypothesis, using flow charts to clearly define inclusion and exclusion criteria, identifying competing risks, and discussing data cleaning methods. Additionally, future efforts should center on creating tailored instruments to better guide reporting in studies using VQI data.

National Institutes of Health funding among vascular surgeons is rare.

BACKGROUND: The National Institutes of Health (NIH) is an essential source of funding for vascular surgeons conducting research. NIH funding is frequently used to benchmark institutional and individual research productivity, help determine eligibility for academic promotion, and as a measure of scientific quality. We sought to appraise the current scope of NIH funding to vascular surgeons by appraising the characteristics of NIH-funded investigators and projects. In addition, we also sought to determine whether funded grants addressed recent Society for Vascular Surgery (SVS) research priorities. METHODS: In April 2022, we queried the NIH Research Portfolio Online Reporting Tools Expenditures and Results (RePORTER) database for active projects. We only included projects that had a vascular surgeon as a principal investigator. Grant characteristics were extracted from the NIH Research Portfolio Online Reporting Tools Expenditures and Results database. Principal investigator demographics and academic background information were identified by searching institution profiles. RESULTS: There were 55 active NIH awards given to 41 vascular surgeons. Only 1% (41/4037) of all vascular surgeons in the United States receive NIH funding. Funded vascular surgeons are an average of 16.3 years out of training; 37% (n = 15) are women. The majority of awards (58%; n = 32) were R01 grants. Among the active NIH-funded projects, 75% (n = 41) are basic or translational research projects, and 25% (n = 14) are clinical or health services research projects. Abdominal aortic aneurysm and peripheral arterial disease are the most commonly funded disease areas and together accounted for 54% (n = 30) of projects. Three SVS research priorities are not addressed by any of the current NIH-funded projects. CONCLUSIONS: NIH funding of vascular surgeons is rare and predominantly consists of basic or translational science projects focused on abdominal aortic aneurysm and peripheral arterial disease research. Women are well-represented among funded vascular surgeons. Although the majority of SVS research priorities receive NIH funding, three SVS research priorities are yet to be addressed by NIH-funded projects. Future efforts should focus on increasing the number of vascular surgeons receiving NIH grants and ensuring all SVS research priorities receive NIH funding.

Resolution of inflammation via RvD1/FPR2 signaling mitigates Nox2 activation and ferroptosis of macrophages in experimental abdominal aortic aneurysms.

Abdominal aortic aneurysm (AAA) formation is characterized by inflammation, leukocyte infiltration, and vascular remodeling. Resolvin D1 (RvD1) is derived from ω-3 polyunsaturated fatty acids and is involved in the resolution phase of chronic inflammatory diseases. The aim of this study was to decipher the protective role of RvD1 via formyl peptide receptor 2 (FPR2) receptor signaling in attenuating abdominal aortic aneurysms (AAA). The elastase-treatment model of AAA in C57BL/6 (WT) mice and human AAA tissue was used to confirm our hypotheses. Elastase-treated FPR2-/- mice had a significant increase in aortic diameter, proinflammatory cytokine production, immune cell infiltration (macrophages and neutrophils), elastic fiber disruption, and decrease in smooth muscle cell α-actin expression compared to elastase-treated WT mice. RvD1 treatment attenuated AAA formation, aortic inflammation, and vascular remodeling in WT mice, but not in FPR2-/- mice. Importantly, human AAA tissue demonstrated significantly decreased FPR2 mRNA expression compared to non-aneurysm human aortas. Mechanistically, RvD1/FPR2 signaling mitigated p47phox phosphorylation and prevented hallmarks of ferroptosis, such as lipid peroxidation and Nrf2 translocation, thereby attenuating HMGB1 secretion. Collectively, this study demonstrates RvD1-mediated immunomodulation of FPR2 signaling on macrophages to mitigate ferroptosis and HMGB1 release, leading to resolution of aortic inflammation and remodeling during AAA pathogenesis.

Eosinophils Protect Mice From Angiotensin-II Perfusion-Induced Abdominal Aortic Aneurysm.

RATIONALE: Blood eosinophil count and ECP (eosinophil cationic protein) associate with human cardiovascular diseases. Yet, whether eosinophils play a role in cardiovascular disease remains untested. The current study detected eosinophil accumulation in human and murine abdominal aortic aneurysm (AAA) lesions, suggesting eosinophil participation in this aortic disease. OBJECTIVE: To test whether and how eosinophils affect AAA growth. METHODS AND RESULTS: Population-based randomized clinically controlled screening trials revealed higher blood eosinophil count in 579 male patients with AAA than in 5063 non-AAA control (0.236±0.182 versus 0.211±0.154, 109/L, P<0.001). Univariate (odds ratio, 1.381, P<0.001) and multivariate (odds ratio, 1.237, P=0.031) logistic regression analyses indicated that increased blood eosinophil count in patients with AAA served as an independent risk factor of human AAA. Immunostaining and immunoblot analyses detected eosinophil accumulation and eosinophil cationic protein expression in human and murine AAA lesions. Results showed that eosinophil deficiency exacerbated AAA growth with increased lesion inflammatory cell contents, matrix-degrading protease activity, angiogenesis, cell proliferation and apoptosis, and smooth muscle cell loss using angiotensin-II perfusion-induced AAA in Apoe-/- and eosinophil-deficient Apoe-/-ΔdblGATA mice. Eosinophil deficiency increased lesion chemokine expression, muted lesion expression of IL (interleukin) 4 and eosinophil-associated-ribonuclease-1 (mEar1 [mouse EOS-associated-ribonuclease-1], human ECP homolog), and slanted M1 macrophage polarization. In cultured macrophages and monocytes, eosinophil-derived IL4 and mEar1 polarized M2 macrophages, suppressed CD11b+Ly6Chi monocytes, and increased CD11b+Ly6Clo monocytes. mEar1 treatment or adoptive transfer of eosinophil from wild-type and Il13-/- mice, but not eosinophil from Il4-/- mice, blocked AAA growth in Apoe-/-ΔdblGATA mice. Immunofluorescent staining and immunoblot analyses demonstrated a role for eosinophil IL4 and mEar1 in blocking NF-κB (nuclear factor-κB) activation in macrophages, smooth muscle cells, and endothelial cells. CONCLUSIONS: Eosinophils play a protective role in AAA by releasing IL4 and cationic proteins such as mEar1 to regulate macrophage and monocyte polarization and to block NF-κB activation in aortic inflammatory and vascular cells.

Presentation and Outcomes of Elective and Nonelective Complex Endovascular Repair for Thoracoabdominal and Juxtarenal Aortic Aneurysms.

BACKGROUND: Endovascular repair of thoracoabdominal aortic aneurysms (TAAA) and juxtarenal aortic aneurysms (JAA) with fenestrated and/or branched endografts (B/FEVAR) has become common. Physician modified endografts for patients presenting with symptomatic or contained ruptures has made B/FEVAR a feasible option in nonelective settings. The purpose of this study was to describe our 10-year institutional experience with endovascular interventions for TAAA in elective and nonelective cases to evaluate differences in outcomes and the clinical risk factors associated with nonelective presentation. METHODS: A prospectively maintained database was retrospectively queried for patients undergoing B/FEVAR for TAAA and JAA at a single tertiary care academic institution between 1/2011 and 12/2020. Data collected included demographics, comorbidities, presenting symptoms, aneurysm characteristics, and clinical outcomes. Nonelective repair was defined as any patient that presented through the Emergency Department, as a hospital transfer, or as a direct admission from clinic and had aortic repair performed during the same admission. Univariate analyses were used to compare patients. The primary outcomes were 30-day and 1-year mortality. Secondary outcomes included perioperative complications and nonhome discharge. RESULTS: Between 1/201 and 12/2020, a total of 208 patients underwent B/FEVAR for TAAA (173) and JAA (35). Nonelective repair was performed in 44 (21%) patients with 39 for TAAA (23%) and 5 for JAA (14%). Nonelective patients were younger (71 ± 11 vs. 74 ± 7 years, P = 0.03), more likely to be self-pay or have Medicaid (11% vs. 2%, P = 0.02) and had a different race distribution compared to the elective cohort (P < 0.01). Thirty-day mortality was 4% (n = 6) in elective repairs and 7% (n = 3) in nonelective repairs. One-year mortality was 13% (n = 22) in elective repairs and 18% (n = 8) in nonelective repairs. There were no differences between patients receiving elective versus nonelective repair in 30-day (P = 0.40) or 1-year mortality (P = 0.47). Nonelective patients had longer median duration of stay (11 interquartile range (IQR) 6-15 vs. 5 IQR 4-8, P < 0.01), postoperative length of stay (7 IQR 5-12 vs. 4 IQR 3-7, P < 0.01), and more intensive care unit days (6 IQR 3-8 vs. 3 IQR 2-5, P < 0.01). There were no differences in other secondary outcomes between elective and nonelective patients including inpatient and access-related complications, re-interventions, and nonhome discharge (P > 0.05 for all comparisons). A composite "any complication" occurred more frequently in patients with nonelective repair (50% vs. 35%, P = 0.03). CONCLUSIONS: Endovascular repair for TAAA or JAA is a good option in patients undergoing nonelective surgical intervention, with comparable 30-day mortality, 1-year mortality, and perioperative morbidity to that of patients undergoing elective B/FEVAR.

Aligning Patient Acuity With Resource Intensity After Major Surgery: A Scoping Review.

OBJECTIVE: Develop unifying definitions and paradigms for data-driven methods to augment postoperative resource intensity decisions. SUMMARY BACKGROUND DATA: Postoperative level-of-care assignments and frequency of vital sign and laboratory measurements (ie, resource intensity) should align with patient acuity. Effective, data-driven decision-support platforms could improve value of care for millions of patients annually, but their development is hindered by the lack of salient definitions and paradigms. METHODS: Embase, PubMed, and Web of Science were searched for articles describing patient acuity and resource intensity after inpatient surgery. Study quality was assessed using validated tools. Thirty-five studies were included and assimilated according to PRISMA guidelines. RESULTS: Perioperative patient acuity is accurately represented by combinations of demographic, physiologic, and hospital-system variables as input features in models that capture complex, non-linear relationships. Intraoperative physiologic data enriche these representations. Triaging high-acuity patients to low-intensity care is associated with increased risk for mortality; triaging low-acuity patients to intensive care units (ICUs) has low value and imparts harm when other, valid requests for ICU admission are denied due to resource limitations, increasing their risk for unrecognized decompensation and failure-to-rescue. Providing high-intensity care for low-acuity patients may also confer harm through unnecessary testing and subsequent treatment of incidental findings, but there is insufficient evidence to evaluate this hypothesis. Compared with data-driven models, clinicians exhibit volatile performance in predicting complications and making postoperative resource intensity decisions. CONCLUSION: To optimize value, postoperative resource intensity decisions should align with precise, data-driven patient acuity assessments augmented by models that accurately represent complex, non-linear relationships among risk factors.

B Cell-Activating Factor Antagonism Attenuates the Growth of Experimental Abdominal Aortic Aneurysm.

B cell-activating factor (BAFF), part of a tumor necrosis factor family of cytokines, was recently identified as a regulator of atherosclerosis; however, its role in aortic aneurysm has not been determined. Here, the study examined the effect of selective BAFF antagonism using an anti-BAFF antibody (blocks binding of BAFF to receptors BAFF receptor 3, transmembrane activator and CAML interactor, and B-cell maturation antigen) and mBaffR-mFc (blocks binding of BAFF to BAFF receptor 3) on a murine model of abdominal aortic aneurysm (AAA). In a prevention strategy, the antagonists were injected before the induction of AAA, and in an intervention strategy, the antagonists were injected after the induction of AAA. Both strategies attenuated the formation of AAA. In the intervention group, BAFF antagonism depleted most of the mature B-cell subsets in spleen and circulation, leading to enhanced resolution of inflammation in AAA as indicated by decreased infiltration of B cells and proinflammatory macrophages and a reduced number of apoptotic cells. In AAA tissues, B cells and macrophages were found in close contact. In vitro, B cells, irrespective of treatment with BAFF, impaired the efferocytosis activity of macrophages, suggesting a direct innate role of B cells on macrophage function. Altogether, BAFF antagonism affects survival of the mature B cells, promotes resolution of inflammation in the aorta, and attenuates the growth of AAA in mice.

Implementation of the Vascular Surgery Board virtual certifying examination.

OBJECTIVE: The onset of the COVID-19 (coronavirus disease 2019) pandemic mandated postponement of the in-person Vascular Surgery Board 2020 certifying examination (CE). Vascular surgery virtual CEs (VVCEs) were developed for the scheduled 2020 CEs (rescheduled to January 2021) and 2021 CEs (rescheduled to July 2021) to avoid postponing the certification testing. In the present study, we have reported the development, implementation, and outcomes of the first two VVCEs. METHODS: The VVCE was similar to the in-person format (three 30-minutes sessions, two examiners, four questions) but required a proctor and a host. In contrast to the general surgery VCEs, the VVCE also incorporated images. The candidates and examiners were instructed on the format, and technology checks were performed before the VVCE. The candidates were given the opportunity to invalidate their examination for technology-related reasons immediately after the examination. Postexamination surveys were administered to all the participants. RESULTS: The VVCEs were completed by 356 of 357 candidates (99.7%). The pass rates for the January 2021 and July 2021 examinations were 97.6% (first time, 99.4%; retake, 70%) and 94.7% (first time, 94.6%; retake, 100%), respectively. The pass rates were not significantly different from the 2019 in-person CE (χ2 = 2.30; P = .13; and χ2 = 0.01; P = .91, for the January 2021 and July 2021 examinations, respectively). None of the candidates had invalidated their examination. The candidates (162 of 356; 46%), examiners (64 of 118; 54%), proctors (25 of 27; 93%), and hosts (8 of 9; 89%) completing the survey were very satisfied with the examination (Likert score 4 or 5: candidates, 92.6%; noncandidates, 96.9%) and found the technology domains (Zoom, audio, video, viewing images) to be very good (Likert score 4 or 5), with candidate and other responder scores of 73% to 84% and >94%, respectively. Significantly more of the candidates had favored a future VVCE compared with the examiners (87% vs 32%; χ2 = 67.1; P < .001). The free text responses from all responders had commented favorably on the organization and implementation of the examination. However, some candidates had expressed concerns about image sizes, and some examiners had expressed concern about the time constraints for the question format. The candidates appreciated the convenience of an at-home examination, especially the avoidance of travel costs. CONCLUSIONS: The two Vascular Surgery Board VCEs were shown to be psychometrically sound and were overwhelmingly successful, demonstrating that image-based virtual examinations are feasible and could become the standard for the future.

Outcomes of endovascular abdominal aortic aneurysm repair conversion in octogenarians treated at a high-volume aorta center.

BACKGROUND: Endovascular abdominal aortic aneurysm repair (EVAR) has become the dominant treatment strategy for infrarenal abdominal aortic aneurysms but has been especially preferred for octogenarian (age ≥80 years) patients because of concerns surrounding comorbidity severity and physiologic frailty. However, EVAR failure resulting in subsequent open conversion (EVAR-c) has been increasingly reported in older patients, although a paucity of literature focusing on the outcomes in this subgroup is available. The purpose of the present analysis was to evaluate our experience with EVAR-c for octogenarians (age ≥80 years) compared with that for younger patients (age <80 years). METHODS: A retrospective review of all nonmycotic EVAR-c procedures (2002-2020) at a single high-volume academic hospital with a dedicated aorta center (available at: https://www.uf-health-aortic-disease-center) was performed. A total of 162 patients were categorized into octogenarian (age ≥80 years; n = 43) and nonoctogenarian (age <80 years; n = 119) cohorts and compared. The primary end point was 30-day mortality. The secondary end points included complications, 90-day mortality, and overall survival. Cox regression was used to determine the effects of selected covariates on mortality risk. The Kaplan-Meier method was used to estimate survival. RESULTS: No differences in the preadmission EVAR reintervention rates were present (octogenarians, 42%; nonoctogenarians, 43%; P = 1.00) although the interval to the first reintervention was longer for the octogenarians (41 months) than for the nonoctogenarians (15 months; P = .01). In addition, the time to EVAR-c was significantly longer for the octogenarian patients (61 months) than for the nonoctogenarian patients (39 months; P < .01). No difference in rupture presentation was evident (14% vs 10%; P = .6). However, elective EVAR-c occurred less frequently for octogenarians (42%) than for nonoctogenarians (59%; P = .07). The abdominal aortic aneurysm diameter was significantly larger for elective octogenarian EVAR-c (7.8 ± 1.9 cm) than for nonoctogenarian EVAR-c (7.0 ± 1.5 cm; P = .02), and the presence of a type Ia endoleak was the most common indication overall (58%; n = 91). A trend toward greater 30-day mortality was evident for octogenarian patients (16%) compared with nonoctogenarian patients (7%; P = .06). Similarly, the 90-day mortality was greater for the octogenarian patients (26%) than for the nonoctogenarian patients (10%; P = .02). However, the incidence of any complication (56% vs 49%; P = .5), readmission rate (12% vs 6%; P = .3), unplanned reoperation rate (10% vs 5%; P = .5), and length of stay (11 days vs 9 days; P = .3) were not significantly different between the two groups. Age ≥80 years was predictive of short-term mortality after nonelective but not after elective surgery. However, increasing comorbidities, nonelective admission, and renal or mesenteric revascularization showed the strongest association with mortality risk. Survival at 1 and 3 years was not different between the two groups when comparing all patients after the first 90 days postoperatively. CONCLUSIONS: Although the unadjusted perioperative mortality was greater for octogenarian patients, the risk-adjusted elective outcomes were comparable to those for younger EVAR-c patients when treated at a high-volume aortic surgery center. This finding underscores the importance of appropriate patient selection and modulation of operative complexity when feasible to achieve optimal results. Providers caring for octogenarian patients with EVAR failure should consider timely elective referral to high-volume aorta centers to reduce resource usage and the frequency of nonelective presentations.

Sex-based differences in patients undergoing thoracic endovascular aortic repair for acute complicated type B dissection.

OBJECTIVE: Sex-based differences in outcomes for patients undergoing degenerative aortic aneurysm repair have been well described, with female patients having worse early and long-term outcomes compared with male patients. However, differences between men and women after thoracic endovascular aortic repair (TEVAR) of acute complicated type B aortic dissection (TBAD) have not been well characterized. Therefore, the objective of the present study was to assess the sex-based differences in clinical presentation, time to repair, morbidity, and mortality for patients undergoing TEVAR for TBAD. METHODS: All TEVAR procedures performed for acute complicated TBAD from a single academic medical center from August 2005 to January 2020 were analyzed. The clinical presentation, time to repair, and outcomes were compared by sex. The primary outcome was 30-day mortality. The secondary outcomes were in-hospital complications, reintervention, aorta-related death, and out of hospital survival. The predictors of mortality, including sex, were determined using multivariable logistic regression. RESULTS: A total of 159 patients (38 women [24%]) were included in the analysis. No sex-based differences were found in clinical presentation or comorbidity prevalence between the female and male patients. The female patients had had a longer overall time from initial symptom onset to TEVAR (female patients: median, 3.5 days [interquartile range (IQR), 1-10 days]; male patients: median, 1 day [IQR, 1-3]; P = .007). However, no differences were found in the time to repair after admission to the academic medical center (female patients: median, 1 day [IQR, 0-5 days]; male patients: median, 1 day [IQR, 0-3]; P = .176). No differences were found in the unadjusted aortic-related, in-hospital, or 30-day death between the female and male patients. Similarly, the risk-adjusted analysis revealed that sex was not associated with adverse outcomes. The 1- and 5-year freedom from aortic-related mortality were 82% ± 4% and 87% ± 6% and 79% ± 4% and 80% ± 8% for the men and women, respectively. CONCLUSIONS: We found no differences between the female and male patients with acute complicated TBAD who had undergone TEVAR in the clinical presentation or comorbidities. The female patients had undergone TEVAR after a longer duration of symptoms, but this was not associated with sex-based differences in early or late morbidity or mortality.

The vascular surgery in-training examination predicts performance on qualifying examination.

OBJECTIVE: Vascular surgery trainees participate in the vascular surgery in-training examination (VSITE) during each year of their training. Although the VSITE was developed as a low-stakes, formative examination, performance on that examination might correlate with the pass rates for the Vascular Surgery Board written qualifying examination (VQE) and oral certifying examination (VCE) and might, therefore, guide both trainees and program directors. The present study was designed to examine the ability of the VSITE to predict trainees' performance on the VQE and VCE. METHODS: All first-time candidates of the Vascular Surgery Board VQE and VCE were analyzed from 2016 to 2020, including those from both the integrated and independent training pathways. VSITE scores from the final year of training were associated with the VQE scores and the probability of passing the VQE and VCE both. Linear and logistic regression models were used to determine the ability of VSITE results to predict the VQE scores and the probability of passing each board examination. RESULTS: VSITE scores available for the 559 candidates (69.3% male; 30.7% female) who had completed the VQE and 369 candidates (66.7% male; 33.3% female) who had completed both the VQE and the VCE. The linear regression model results for the final year of training showed that the VSITE scores explained 34% of the variance in the VQE scores (29% for the integrated and 37% for the independent trainees). Logistic regression demonstrated that the final year VSITE scores were a significant predictor of passing the VQE for both integrated and independent trainees (P < .001). A VSITE score of 500 during the final year of training predicted a VQE passing probability of >90% for each group of candidates. The probability of passing the VQE decreased to 73% for candidates from integrated programs, 61% for candidates from independent programs, and 64% for the whole cohort when the score was 400. The VSITE scores were a significant predictor of passing the VCE only for the candidates from independent programs (odds ratio, 1.01; 95% confidence interval, 1.00-1.02; P < .01), for whom a VSITE score of 400 correlated with an 82% probability of passing the VCE. CONCLUSIONS: VSITE performance is predictive of passing the VQE for trainees from both integrated and independent training paradigms. Vascular surgery trainees and training programs should optimize their preparation and educational efforts to maximize performance on the VSITE during their final year of training to improve the likelihood of passing the VQE. Further analysis of the predictive value of VSITE scores during the earlier years of training might allow the board certification examinations to be administered earlier in the final year of training.