Blood flow assessment technology in aortic surgery: a narrative review.

Background and Objective: Blood flow assessment is an emerging technique that allows for assessment of hemodynamics in the heart and blood vessels. Recent advances in cardiovascular imaging technologies have made it possible for this technique to be more accessible to clinicians and researchers. Blood flow assessment typically refers to two techniques: measurement-based flow visualization using echocardiography or four-dimensional flow magnetic resonance imaging (4D flow MRI), and computer-based flow simulation based on computational fluid dynamics modeling. Using these methods, blood flow patterns can be visualized and quantitative measurements of mechanical stress on the walls of the ventricles and blood vessels, most notably the aorta, can be made. Thus, blood flow assessment has been enhancing the understanding of cardiac and aortic diseases; however, its introduction to clinical practice has been negligible yet. In this article, we aim to discuss the clinical applications and future directions of blood flow assessment in aortic surgery. We then provide our unique perspective on the technique's translational impact on the surgical management of aortic disease. Methods: Articles from the PubMed database and Google Scholar regarding blood flow assessment in aortic surgery were reviewed. For the initial search, articles published between 2013 and 2023 were prioritized, including original articles, clinical trials, case reports, and reviews. Following the initial search, additional articles were considered based on manual searches of the references from the retrieved literature. Key Content and Findings: In aortic root pathology and ascending aortic aneurysms, blood flow assessment can elucidate postoperative hemodynamic changes after surgical reconfiguration of the aortic valve complex or ascending aorta. In cases of aortic dissection, analysis of blood flow can predict future aortic dilatation. For complicated congenital aortic anomalies, surgeons may use preoperative imaging to perform "virtual surgery", in which blood flow assessment can predict postoperative hemodynamics for different surgical reconstructions and assist in procedural planning even before entering the operating room. Conclusions: Blood flow assessment and computational modeling can evaluate hemodynamics and flow patterns by visualizing blood flow and calculating biomechanical forces in patients with aortic disease. We anticipate that blood flow assessment will become an essential tool in the treatment planning and understanding of the progression of aortic disease.

Association between Asian race and perioperative outcomes after carotid revascularization varies with Asian procedure density.

OBJECTIVE: Postoperative outcomes following carotid revascularization are understudied in Asian patients. We aimed to assess whether disease severity and postoperative outcomes following carotid revascularization differ between Asian and White patients, and whether this varies with Asian procedure density. METHODS: We analyzed the Vascular Quality Initiative Carotid Endarterectomy and Carotid Artery Stenting datasets from 2003 to 2021. Regions were divided into tertiles based on Asian procedure density. Propensity scores were used to match Asian and White patients based on patient factors and procedure type. The primary outcome variable was a collapsed composite of in-hospital ipsilateral stroke/death/myocardial infarction. χ2 tests were used to assess association between Asian race and disease severity, center and surgeon volume, and 1-year outcomes. Logistic and Cox regressions were performed between the matched cohorts. RESULTS: A total of 1766 Asian and 159,608 White patients underwent carotid revascularization, and we identified 2704 patients (1352 Asian and 1352 White) in the matched cohorts. Among propensity matched patients, all-comer Asian patients more commonly had >80% ipsilateral stenosis (63% vs 52%; P < .001) and a moderate/severe preoperative Rankin score (7.6% vs 5.1%; P = .007). The rate of in-hospital stroke/death/myocardial infarction was higher in Asian patients (2.6% vs 1.3%; P = .012), and this disparity was more pronounced in the lowest tertile of Asian procedure density (4.3% vs 0.5%; P < .001). Logistic regression in the propensity-matched cohort demonstrated Asian race was associated with lower odds of intervention at highest volume centers (odds ratio [OR], 0.3; 95% confidence interval [CI], 0.2-0.3; P < .001) and by highest volume surgeons (OR, 0.3; 95% CI, 0.3-0.4; P < .001). Asian race was associated with higher odds of in-hospital stroke/death/myocardial infarction (OR, 2.0; 95% CI, 1.1-3.8; P = .031), and there was a significant interaction between Asian procedure density and the relationship between Asian race and this outcome (interaction P = .001). After accounting for center and surgeon volume, the association of Asian race and the composite outcome was mitigated (OR, 1.5; 95% CI, 0.7-3.3; P = .300). Cox regression between the matched cohorts demonstrated that Asian race was associated with lower 1-year mortality (hazard ratio, 0.5; 95% CI, 0.3-0.7; P = .001) and higher risk of 1-year reintervention (hazard ratio, 16; 95% CI, 1.8-142; P = .013). CONCLUSIONS: Asian patients are more likely to present with a higher degree of carotid stenosis, higher preoperative risk, and experience worse perioperative outcomes. The association of Asian race with perioperative stroke/death/myocardial infarction varies with Asian procedure density and is also confounded by center and surgeon volume. These results highlight the importance of understanding referral patterns and cultural effects on outcomes disparities in Asian patients.

Reduced Intravenous Contrast Dose Portal Venous Phase Photon-Counting Computed Tomography Compared With Conventional Energy-Integrating Detector Portal Venous Phase Computed Tomography.

OBJECTIVE: The aim of this study was to compare portal venous phase photon-counting CT (PCCT) using 20 cc less than weight-based contrast dosing with energy-integrating detector CT (EID-CT) using weight-based dosing by quantitative and qualitative analysis. METHODS: Fifty adult patients who underwent a reduced intravenous contrast dose portal venous phase PCCT from May 1, 2023, to August 10, 2023, and a prior portal-venous EID-CT with weight-based contrast dosing were retrospectively identified. Hounsfield units (HU) and noise (SD of HU) were obtained from region-of-interest measurements on 70-keV PCCT and EID-CT in 4 hepatic segments, the main and right portal vein, and both paraspinal muscles. Signal-to-noise and contrast-to-noise ratios were computed. Three abdominal radiologists qualitatively assessed overall image quality, hepatic enhancement, and confidence for metastasis identification on 5-point Likert scales. Readers also recorded the presence/absence of hepatic metastases. Quantitative variables were compared with paired t tests, and multiple comparisons were accounted for with a Bonferroni-adjusted α level of .0016. Ordinal logistic regression was used to evaluate qualitative assessments. Interreader agreement for hepatic metastases was calculated using Fleiss' κ. RESULTS: Fifty patients (32 women; mean [SD] age, 64 [13] years) were included. There was no significant difference in hepatic HU, portal vein HU, noise, and signal-to-noise or contrast-to-noise ratio between reduced contrast dose portal venous phase PCCT versus EID-CT (all Ps > 0.0016). Image quality, degree of hepatic enhancement, and confidence for metastasis identification were not different for reduced dose PCCT 70-keV images and EID-CT (P = 0.06-0.69). κ Value for metastasis identification was 0.86 (95% confidence interval, 0.70-1.00) with PCCT and 0.78 (95% confidence interval, 0.59-0.98) with EID-CT. CONCLUSION: Reduced intravenous contrast portal venous phase PCCT 70-keV images had similar attenuation and image quality as EID-CT with weight-based dosing. Metastases were identified with near-perfect agreement in reduced dose PCCT 70-keV images.

Longitudinal assessment of health-related quality of life and clinical outcomes with at home advanced pneumatic compression treatment of lower extremity lymphedema.

OBJECTIVE: This prospective, longitudinal, pragmatic study describes at home treatment with a proprietary advanced pneumatic compression device (APCD) for patients with lower extremity lymphedema (LED). METHODS: Following institutiona review board approval, four participating Veterans Affairs centers enrolled LED patients from 2016 to 2022. The primary outcome measures were health-related quality of life (HR-QoL) questionnaires (lymphedema quality of life-leg and the generic SF-36v2) obtained at baseline and 12, 24, and 52 weeks. The secondary outcome measures were limb circumference, cellulitis events, skin quality, and compliance with APCD and other compression therapies. RESULTS: Because a portion of the trial was conducted during the coronavirus disease 2019 pandemic, 179 patients had 52 weeks of follow-up, and 143 had complete measurements at all time points. The baseline characteristics were a mean age of 66.9 ± 10.8 years, 91% were men, and the mean body mass index was 33.8 ± 6.9 kg/m2. LED was bilateral in 92.2% of the patients. Chronic venous insufficiency or phlebolymphedema was the most common etiology of LED (112 patients; 62.6%), followed by trauma or surgery (20 patients; 11.2%). Cancer treatment as a cause was low (4 patients; 2.3%). Patients were classified as having International Society for Lymphology (ISL) stage I (68.4%), II (27.6%), or III (4.1%). Of the primary outcome measures, significant improvements were observed in all lymphedema quality of life-leg domains of function, appearance, symptoms, and emotion and the overall score after 12 weeks of treatment (P < .0001) and through 52 weeks of follow-up. The SF-36v2 demonstrated significant improvement in three domains at 12 weeks and in the six domains of physical function, bodily pain, physical component (P < .0001), social functioning (P = .0181), role-physical (P < .0005), and mental health (P < .0334) at 52 weeks. An SF-36v2 score <40 indicates a substantial reduction in HR-QoL in LED patients compared with U.S. norms. Regarding the secondary outcome measures at 52 weeks, compared with baseline, the mean limb girth decreased by 1.4 cm (P < .0001). The maximal reduction in mean limb girth was 1.9 cm (6.0%) at 12 weeks in ISL stage II and III limbs. New episodes of cellulitis in patients with previous episodes (21.4% vs 6.1%, P = .001) were reduced. The 75% of patients with skin hyperpigmentation at baseline decreased to 40% (P < .01) at 52 weeks. At 52 weeks, compliance, defined as use for 5 to 7 days per week, was reported for the APCD by 72% and for elastic stockings by 74%. CONCLUSIONS: This longitudinal study of Veterans Affairs patients with LED demonstrated improved generic and disease-specific HR-QoL through 52 weeks with at home use of an APCD. Limb girth, cellulitis episodes, and skin discoloration were reduced, with excellent compliance.

Long-term costs to Medicare associated with endovascular and open repairs of infrarenal and complex abdominal aortic aneurysms.

OBJECTIVE: The vast majority of patients with abdominal aortic aneurysms (AAAs) undergoing repairs receive endovascular interventions (EVARs) instead of open operations (OARs). Although EVARs have better short-term outcomes, OARs have improved longer-term durability and require less radiographic follow-up and monitoring, which may have significant implications on health care economics surrounding provision of AAA care nationally. Herein, we compared costs associated with EVAR and OAR of both infrarenal and complex AAAs. METHODS: We examined patients undergoing index elective EVARs or OARs of infrarenal and complex AAAs in the 2014-2019 Vascular Quality Initiative-Vascular Implant Surveillance and Interventional Outcomes Network (VQI-VISION) dataset. We defined overall costs as the aggregated longitudinal costs associated with: (1) the index surgery; (2) reinterventions; and (3) imaging tests. We evaluated overall costs up to 5 years after infrarenal AAA repair and 3 years for complex AAA repair. Multivariable regressions adjusted for case-mix when evaluating cost differences between EVARs vs OARs. RESULTS: We identified 23,746 infrarenal AAA repairs (8.7% OAR, 91% EVAR) and 2279 complex AAA repairs (69% OAR, 31% EVAR). In both cohorts, patients undergoing EVARs were more likely to be older and have more comorbidities. The cost for the index procedure for EVARs relative to OARs was lower for infrarenal AAAs ($32,440 vs $37,488; P < .01) but higher among complex AAAs ($48,870 vs $44,530; P < .01). EVARs had higher annual imaging and reintervention costs during each of the 5 postoperative years for infrarenal aneurysms and the 3 postoperative years for complex aneurysms. Among patients undergoing infrarenal AAA repairs who survived 5 years, the total 5-year cost of EVARs was similar to that of OARs ($35,858 vs $34,212; -$223 [95% confidence interval (CI), -$3042 to $2596]). For complex AAA repairs, the total cost at 3 years of EVARs was greater than OARs ($64,492 vs $42,212; +$9860 [95% CI, $5835-$13,885]). For patients receiving EVARs for complex aneurysms, physician-modified endovascular grafts had higher index procedure costs ($55,835 vs $47,064; P < .01) although similar total costs on adjusted analyses (+$1856 [95% CI, -$7997 to $11,710]; P = .70) relative to Zenith fenestrated endovascular grafts among those that were alive at 3 years. CONCLUSIONS: Longer-term costs associated with EVARs are lower for infrarenal AAAs but higher for complex AAAs relative to OARs, driven by reintervention and imaging costs. Further analyses to characterize the financial viability of EVARs for both infrarenal and complex AAAs should evaluate hospital margins and anticipated changes in costs of devices.

Utility of structured follow-up imaging after aortic surgery.

BACKGROUND: Although postoperative follow-up after aortic surgery is recommended by guidelines, its clinical utility is not well documented. We hypothesized that structured follow-up imaging by an aortic program would improve outcomes. We then documented radiologic findings on asymptomatic postoperative imaging. METHODS: All patients who survived to discharge after open thoracic aortic surgery between January 2017 and July 2021 were included, excluding endocarditis. Patients who followed at our center and received scheduled imaging were compared with patients who did not. Survival was analyzed by the method of Kaplan-Meier, and reintervention was assessed using the Fine-Gray subhazard function. Routine imaging was reviewed for aortic growth, pseudoaneurysm, and perigraft density. RESULTS: After aortic surgery, the cumulative incidence of follow-up was 38.6% at 3 years postoperatively. Patients with follow-up were more likely to have a dissection and fewer comorbidities but were similar in regards to socioeconomic factors and distance to hospital. After matching and accounting for immortal time bias, patients with follow-up had a greater reintervention rate (26.0% vs 9.0%) with similar survival (98.7% vs 95.2%, P = .110) at 4 years. The cumulative incidence of pseudoaneurysm, significant perigraft density, and growth ≥3 mm/year on routine imaging was 49.7% at 3 years. CONCLUSIONS: Implementation of structured follow-up imaging by an aortic program resulted in low clinical compliance. Follow-up was associated with increased rates of aortic reintervention. Clinically relevant radiologic findings were common on asymptomatic imaging and increased throughout 5-year follow-up rather than plateauing in the early postoperative period.

National trends in utilization of surgeon-modified grafts for complex and thoracoabdominal aortic aneurysms.

INTRODUCTION: Custom-branched/fenestrated grafts are widely available in other countries, but in the United States, they are limited to a handful of centers, with the exception of a 3-vessel juxtarenal device (ZFEN). Consequently, many surgeons have turned to alternative strategies such as physician-modified endografts (PMEGs). We therefore sought to determine how widespread the use of these grafts is. METHODS: We studied all complex endovascular repairs of complex and thoracoabdominal aortic aneurysms in the Vascular Quality Initiative from 2014 to 2022 to examine temporal trends. RESULTS: A total of 5826 repairs were performed during the study period: 1895 ZFEN, 3241 PMEG, 595 parallel grafting, and 95 where parallel grafting was used in addition to ZFEN, with a mean of 2.7 ± 0.98 vessels incorporated. Over time, the number of PMEGs steadily increased, both overall and for juxtarenal aneurysms, whereas the number of ZFENs essentially leveled off by 2017 and has remained steady ever since. In the most recent complete year (2021), PMEGs outnumbered ZFENs by over 2:1 overall (567 to 256) and nearly twofold for juxtarenal repairs. In three-vessel cases involving juxtarenal aneurysms, PMEGs were used as frequently as ZFENs (43% vs 43%), whereas the proportion of juxtarenal aneurysms repaired using a four-vessel graft configuration increased from 20% in 2014 to 29% in 2021 (P < .001). The differences in PMEG use were more pronounced as surgeon volume increased. Surgeons in the lowest quartile of volume performed <2 complex repairs annually, evenly split between PMEGs and ZFENs. However, surgeons in the highest quartile of volume performed a median of 18 (interquartile range: 10-21) PMEGs/y, but only 1.6 (interquartile range: 0.8-3.4) ZFENs/y. The number of physician-sponsored investigational device exemption trials of PMEGs has expanded from 1 in 2012 to 8 currently enrolling. As those data are not included in the Vascular Quality Initiative, the true number of PMEGs is likely substantially higher. CONCLUSIONS: PMEGs have become the dominant endovascular repair modality of complex abdominal and thoracoabdominal aortic aneurysms outside of investigational device exemptions. The field of endovascular aortic surgery and patients with complex aneurysms would benefit from broader publication of PMEG techniques, outcomes, and comparisons to custom-manufactured grafts.

Editor's Choice -- Age Stratified Midterm Survival Following Endovascular Versus Open Repair of Juxtarenal Abdominal Aortic Aneurysms.

OBJECTIVE: Age stratified mortality was examined following fenestrated endovascular aneurysm repair (F-EVAR) vs. open repair of juxtarenal abdominal aortic aneurysms (AAAs) METHODS: All patients undergoing first time elective F-EVAR and complex open aneurysm repair (c-OAR) for juxtarenal AAA in the Vascular Quality Initiative between 2014 and 2021 were identified. Open repairs were compared with commercially available fenestrated endovascular aneurysm repair and physician modified endografts (PMEGs). Patients were stratified into three age groups (< 65, 65 - 75, > 75 years). Primary outcomes were peri-operative and five year mortality, and inverse probability weighted risk adjustment was performed to account for baseline differences. RESULTS: Overall, 1 961 patients underwent F-EVAR (82% commercial F-EVAR, 18% PMEG) and 3 385 patients underwent c-OAR. Across age groups, the distribution of F-EVAR (vs. c-OAR) was: < 65 years: 23%, 65 - 75 years: 33%, > 75 years: 52%. After adjustment, among patients < 65 years, compared with c-OAR, F-EVAR was associated with similar peri-operative mortality (0.9% vs. 2.1%; hazard ratio [HR] 0.40, 95% confidence interval [CI] 0.07 - 1.44], p = .22), and five year mortality (13% vs. 9.5%; HR 1.44, 95% CI 0.71 - 2.90, p = .31). Among patients aged 65 - 75 years, between juxtarenal AAA repair modalities, compared with c-OAR, F-EVAR was associated with a significantly lower risk of peri-operative mortality (2.2% vs. 5.0%; HR 0.50, 95% CI 0.30 - 0.79, p = .004), and five year mortality (13% vs. 13%; HR 0.94, 95% CI 0.65 - 1.36, p = .74). Similarly, among patients > 75 years, compared with c-OAR, F-EVAR was associated with lower peri-operative mortality (2.2% vs. 6.5%; HR 0.26, 95% CI 0.13 - 0.47, p < .001), but with similar five year mortality (18% vs. 21%; HR 0.83, 95% CI 0.57 - 1.20, p = .31). CONCLUSION: Among patients with a juxtarenal AAA, F-EVAR was associated with a lower peri-operative mortality compared with c-OAR in patients ≥ 65 years, but was similar in those < 65 years. At five years, F-EVAR was associated with similar mortality in all age groups, though there was a non-significant trend for a higher mortality rate in younger patients.

The critical role of phlebolymphedema in cellulitis associated with lymphedema: Its incidence and economic impact in a large real-world population.

OBJECTIVE: The aims of this study were: to define the incidence of cellulitis in patients with lymphedema (LED) overall and relate this to the etiology of LED; to determine how this rate might be affected by recurrence of cellulitis; and to quantify the contemporary economic burden of treatment. Understanding these factors is essential in developing targeted cellulitis prevention strategies and reducing health care costs. METHODS: The IBM MarketScan Research Database was examined from April 2013 to March 2019 for patients with a new diagnosis of LED (n = 85,601). Based on International Classification of Diseases (ICD)-9/ICD-10 diagnosis codes, the incidence and cost of cellulitis were ascertained during the 3-year follow-up period. Incidence rates (per 100 patient-years [PYs]) and cost (per patient per year) of cellulitis were evaluated among all patients with LED and within subgroups of LED etiologies. RESULTS: Among the three most common morbidities associated with LED (breast cancer-related lymphedema [BCRL], n = 17,954 [20.97%]; gynecological cancer-related LED [GCRL], n = 1256 [1.47%]; and phlebolymphedema [PLED], n = 8406 [9.82%]), rates of cellulitis were markedly lower for BCRL (8.9; 95% confidence interval [CI], 8.7-9.2) and GCRL (14.8; 95% CI, 13.4-16.4) vs PLED (47.7; 95% CI, 46.7-48.8). Patients with a history of cellulitis had markedly higher cellulitis rates during follow-up than those without-overall, 74.0% vs 16.4%; BCRL, 42.9%; 95% CI, 39.7%-46.3% vs 7.6%; 95% CI, 7.3%-7.9%; GCRL, 67.5%; 95% CI, 56.4%-80.8% vs 11.0%; 95% CI, 9.8%-12.4%; and PLED, 81.7%; 95% CI, 79.4%-84.1% vs 30.4%; 95% CI, 29.4%-31.4%, respectively. The mean $/patient/year of cellulitis-related costs for a patient with PLED ($2836; 95% CI, $2395-$3471) was significantly greater than that for BCRL ($503; 95% CI, $212-$1387) and GCRL ($609; 95% CI, $244-$1314). CONCLUSIONS: The incidence of cellulitis associated with LED varies by the etiology of LED. PLED has the highest rates of both an initial cellulitis episode and recurrent cellulitis events. Additionally, PLED has one of the largest cellulitis-related total costs per patient per year. Prevention, as well as early identification and treatment of PLED-associated cellulitis, could significantly decrease health care costs and improve patient quality of life.

One-year aneurysm-sac dynamics are associated with reinterventions and rupture following infrarenal endovascular aneurysm repair.

OBJECTIVE: One-year aneurysm sac changes have previously been found to be associated with mortality and may have the potential to guide personalized follow-up following endovascular aneurysm repair (EVAR). In this study, we examined the association of these early sac changes with long-term reintervention and rupture. METHODS: We identified all patients undergoing first-time EVAR for intact abdominal aortic aneurysm between 2003 and 2018 in the Vascular Quality Initiative with linkage to Medicare claims for long-term outcomes. We included patients with an imaging study at 1 year postoperatively. Aneurysm sac behavior was defined as per the Society for Vascular Surgery guidelines: stable sac (<5 mm change), sac regression (≥5 mm), and sac expansion (≥5 mm). Outcomes included mortality, reintervention, and rupture within 8 years, which were assessed with Kaplan-Meier methods and multivariable Cox regression analysis. Secondarily, we utilized polynomial spline interpolation to demonstrate the continuous relationship of diameter change to 8-year hazard of reintervention, rupture, or mortality as a composite outcome. RESULTS: Of 31,185 EVAR patients, 16,102 (52%) had an imaging study at 1 year and were included in this study. At 1 year, 44% of sacs remained stable, 49% regressed, and 6.2% displayed expansion. Following risk adjustment, compared with a stable sac at 1 year, sac regression was associated with lower 8-year mortality (49% vs 53%; hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.85-0.99; P = .036), reintervention rate (8.9% vs 15%; HR, 0.58; 95% CI, 0.50-0.68; P < .001), and rupture rate (2.0% vs 4.0%; HR, 0.45; 95%CI, 0.29-0.69; P < .001). Conversely, compared with a stable sac, sac expansion was associated with higher 8-year mortality (64% vs 53%; HR, 1.31; 95% CI, 1.14-1.51; P < .001) and reintervention rate (27% vs 15%; HR, 1.98; 95% CI, 1.57-2.51; P < .001), but similar risk of rupture (7.2% vs 4.0%; HR, 1.61; 95% CI, 0.88-2.96; P = .12). Polynomial spline interpolation demonstrated that, compared with no diameter change at 1 year, increased sac regression was associated with an incrementally lower risk of late outcomes, whereas increased sac expansion was associated with an incrementally higher risk of late outcomes. CONCLUSIONS: Following EVAR, compared with a stable sac at 1-year imaging, sac regression and expansion are associated with a lower and higher risk respectively of long-term mortality, reinterventions, and ruptures. Moreover, the amount of regression or expansion seems to be incrementally associated with these late outcomes, too. Future studies are needed to determine how to improve 1-year sac regression, and whether it is safe to extend follow-up intervals for patients with regressing sacs.

Outcomes of Staged Repairs of Complex Endovascular Repairs of Thoracoabdominal Aortic Aneurysms.

BACKGROUND: Endovascular treatment allows for the staging of thoracoabdominal aortic aneurysm repairs (eTAAAs) in an effort to decrease the risk of spinal cord ischemia (SCI), but data are limited. METHODS: We studied all eTAAAs in the Vascular Quality Initiative from 2014 to 2021. Inverse probability weighting was used to compare perioperative and long-term outcomes of staged and single-stage repairs. Thoracoabdominal life-altering events (TALEs) are the composite endpoint consisting of death/stroke/permanent SCI/permanent dialysis. RESULTS: There were 3,258 total operations during the study period. In total, 841 cases (26%) were staged repairs, and 2,417 (74%) were completed in a single stage, but in the cohort of patients with extensive aneurysms, 44% were staged. Staging methods included thoracic endograft (78%), branch (23%), and iliac (5%). Staged repairs were more often employed by high-volume surgeons at high-volume centers; for larger, more extensive aneurysms, with higher rates of prior aortic surgery. After adjustment, staged repair and single-stage treatment were associated with similar odds of all perioperative outcomes and including mortality, TALE, acute kidney injury, stroke, dialysis, and SCI, as well as long-term survival. This was consistent in the subgroups of patients with extensive aneurysms undergoing elective procedures. Of note, first-stage thoracic endografts were associated with 2.6% mortality, 7.3% TALE, 1.5% dialysis, and 4.1% SCI, and 25% of patients did not undergo a second stage. First-stage procedures accounted for one-third of perioperative complications including half of the deaths in the staged cohort. CONCLUSIONS: Staged eTAAA repairs were associated with similar perioperative and long-term complications to single-stage treatments. However, first stage procedures are associated with significant morbidity and mortality, and one-quarter of patients never complete their repairs. These data demonstrate the necessity of evaluating the outcomes of all patients planned for staged procedures, not only those who make it to the final stage. More data are needed as to the optimal method of spinal cord protection for these challenging aneurysms.

Lymphoscintigraphy is frequently recommended but seldom used in a "real world setting".

OBJECTIVE: Lymphedema (LED) lacks a standard, simple, guiding noninvasive diagnostic test, unlike the two other circulatory disorders-arterial or venous disease. Lymphoscintigraphy (LSG) has been recommended by several guidelines as the diagnostic test of choice for LED. Several recent expert panels, however, have suggested from anecdotal experience that LSG was used infrequently, and that the diagnosis of LED is usually based on clinical examination. METHODS: To determine the use of LSG in a large real-world LED population, the International Business Machines MarketScan Research Database was examined from April 2012 to March 2020 for patients with a new diagnosis of LED (the index date). Use of LSG (LSG+) was ascertained during the period beginning 12 months prior to the initial coding of a LED diagnosis and ending 12 months after the index date based on the corresponding Current Procedural Terminology code; LSG use for sentinel node mapping at the time of oncologic surgery was excluded. Demographic profiles, comorbidities, and causes of LED among patients with and without evidence of LSG were characterized. RESULTS: We identified 57,674 patients, aged ≥18 years, who had a new diagnosis of LED and health care coverage for ≥12 months before and after this index date. Only a small number (1429; 2.5%) of these patients underwent LSG during the study period. The LSG + cohort was younger (53.7 vs 60.7 years), had a higher proportion of women (91.3% vs 73.4%), but a lower percentage of diabetes (12.8% vs 27.5%), heart failure (2.2% vs 8.7%), hypertension (32.4% vs 51.0%), and obesity (15.1% vs 22.2%) compared with the LED population who did not undergo LSG (all P < .001). Most importantly, the use of LSG for diagnosis varied with the etiology of LED (LSG was most frequently utilized among patients with melanoma-LED (9.5%) and patients with breast cancer-LED (6.7%), in contrast to patients with advanced venous disease-related LED (1.1%; P < .05 for both comparisons). CONCLUSIONS: Despite four guidelines recommending LSG, including the Guidelines of the American Venous Forum (Handbook of Venous and Lymphatic Disease-4th edition), which recommended LSG "for the initial evaluation of patients with LED" with a 1B recommendation, LSG plays a minor role in establishing the diagnosis of LED in the United States. This underlines the need for a better, simple diagnostic test for LED to complement clinical examination.

Low-volume surgeons can have better outcomes at certain hospital settings for open abdominal aortic repairs.

OBJECTIVE: The volume-outcomes relationship is cross-cutting among open abdominal aortic operations, where higher-volume surgeons have better perioperative outcomes. However, there has been minimal focus on low-volume surgeons and how to improve their outcomes. This study sought to identify if there are any differences in outcomes among low-volume surgeons for open abdominal aortic surgeries by different hospital settings. METHODS: We used the 2012-2019 Vascular Quality Initiative registry to identify all patients who underwent open abdominal aortic surgery for aneurysmal or aorto-iliac occlusive disease by a low-volume surgeon (<7 operations annually). We categorized high-volume hospitals using three distinct definitions: those that performed ≥10 operations annually, those with at least one high-volume surgeon, and by the number of surgeons (1-2 surgeons, 3-4 surgeons, 5-7 surgeons, and 8+ surgeons). Outcomes included 30-day perioperative mortality, overall complications, and failure-to-rescue. We compared outcomes among low-volume surgeons using univariable and multivariable logistic regressions across each of these three hospital categorizations. RESULTS: Among 14,110 patients who underwent open abdominal aortic surgery, 10,252 (7 3%) were performed by 1155 low-volume surgeons. Two-thirds of these patients (66%) underwent their surgery at a high-volume hospital, fewer than one-third (30%) at a hospital that had at least one high-volume surgeon, and one-half (49%) at hospitals with at least five surgeons. Among all patients operated on by low-volume surgeons, rates of 30-day mortality were 3.8%, perioperative complications were 35.3%, and failure-to-rescue were 9.9%. Low-volume surgeons operating at high-volume hospitals for aneurysmal disease had lower rates of perioperative death (adjusted odds ratio [aOR], 0.66; 95% confidence interval [CI], 0.48-0.90) and failure-to-rescue (aOR, 0.70; 95% CI, 0.50-0.98), but similar rates of complications (aOR, 1.06; 95% CI, 0.89-1.27). Similarly, patients undergoing their operation at hospitals that had at least one high-volume surgeon had lower rates of death (aOR, 0.71; 95% CI, 0.50-0.99) for aneurysmal disease. Patient outcomes among low-volume surgeons for aorto-iliac occlusive disease did not vary by hospital setting. CONCLUSIONS: The majority of patients undergoing open abdominal aortic surgery have a low-volume surgeon, where outcomes are slightly better for those taking place at a high-volume hospital. Focused and incentivized interventions may be needed to improve outcomes among low-volume surgeons across all practice settings.

Thoracoabdominal aortic aneurysm life-altering events following endovascular aortic repair in the Vascular Quality Initiative.

OBJECTIVE: Endovascular aortic aneurysm repair (EVAR) has lower rates of postoperative mortality and morbidity when compared with open repair. However, endovascular repair still carries the risk of postoperative dialysis, paralysis, and stroke. This study examined the rates of postoperative mortality and morbidity stratified by type of endovascular aortic aneurysm repair. METHODS: All patients who underwent EVAR in the Vascular Quality Initiative registry from January 2011 to May 2022 were identified. Patients were stratified by repair type: infrarenal EVAR, complex EVAR, thoracic endovascular aortic repair (TEVAR), extent I to III thoracoabdominal aortic aneurysm (TAAA) repair, or aortic arch repair. The primary outcome was postoperative thoracoabdominal aortic aneurysm life-altering events (TALE) across the different treatment groups. TALE was defined as a composite outcome of postoperative mortality, dialysis, paralysis, and/or stroke. Mixed effect logistic regression modeling was used to identify procedural and anatomic factors that were independently associated with TALE. RESULTS: A total of 52,592 EVARs, 3768 complex EVARs, 3899 TEVARs, 1139 extent I to III TAAA repairs, and 479 arch repairs were identified. TALE was observed in 1.2% of EVARs, 4.8% of complex EVARs, 6.0% of TEVARs, 10% of extent I to III TAAA repairs, and 14% of arch repairs. More proximal landing zone was associated with higher odds of TALE after complex EVAR (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.2-3.1; P = .008), TEVAR (OR, 2.2; 95% CI, 1.4-3.5; P = .001), and extent I to III TAAA repair (OR, 2.7; 95% CI, 1.5-4.9; P = .001). Aortic diameter >65 mm was associated with higher odds of TALE after infrarenal EVAR (OR, 1.8; 95% CI, 1.4-2.3; P < .001), complex EVAR (OR, 1.6; 95% CI, 1.1-2.3; P = .010), TEVAR (OR, 2.7; 95% CI, 2.0-3.8; P < .001), and arch repair (OR, 2.4; 95% CI, 1.3-4.4; P = .007). The use of parallel grafting technique (chimney/snorkel/periscope) during extent I to III TAAA repair was also associated with higher odds of TALE (OR, 1.8; 95% CI, 1.1-3.2; P = .032). Preoperative chronic kidney disease was also associated with higher odds of TALE after infrarenal EVAR (OR, 4.3; 95% CI, 3.0-5.7; P < .001), complex EVAR (OR, 5.2; 95% CI, 3.3-8.2; P < .001), TEVAR (OR, 4.5; 95% CI, 2.8-7.1; P < .001), and extent I to III TAAA repair (OR, 3.2; 95% CI, 1.6-6.7; P = .001). CONCLUSIONS: Although TALE was originally described for TAAA repairs, TALE may occur after complex EVAR, TEVAR, and arch repairs as well. Therefore, TALE and its component parts should be used to evaluate the efficacy of all aortic repairs and for preoperative counseling. Additionally, surgeons should be aware of anatomic and procedural characteristics that are associated with higher odds of TALE. The anticipated need for such interventions during aortic repair should be factored into preoperative risk assessment of patients.

Crohn's disease phenotype analysis with iodine density from dual-energy CT enterography.

PURPOSE: To compare dual-source dual-energy CT enterography (dsDECTE) obtained iodine density (I) (mg/mL) and I normalized to the aorta (I%) with Crohn's disease (CD) phenotypes defined by the SAR-AGA small bowel CD consensus statement. METHODS: Fifty CD patients (31 male, 19 female; mean [SD] age: 50.4 [15.2] years) who underwent dsDECTE were retrospectively identified. Two abdominal radiologists assigned CD phenotypes: no active inflammation (group-2), active inflammation without (group-3) or with luminal narrowing (group-4), stricture with active inflammation (group-5), stricture without active inflammation (group-1), and penetrating disease (group-6). Semiautomatic prototype software was used to determine the median I and I% of CD-affected small bowel mucosa for each patient. The means of the I and I% medians were compared among 4 groups ("1 + 2", "3 + 4", "5", "6") using one-way ANOVA (significance level 0.05 for each outcome) for each outcome individually followed by Tukey's range test for pairwise comparisons with adjusted p-values (overall alpha = 0.05). RESULTS: Mean [SD] I was 2.14 [1.07] mg/mL for groups 1 + 2 (n = 16), 3.54 [1.71] mg/mL for groups 3 + 4 (n = 15), 5.5 [3.27] mg/mL for group- "5" (n = 9), and 3.36 [1.43] mg/mL for group-"6" (n = 10) (ANOVA p = .001; group "1 + 2" versus "5" adj-p = .0005). Mean [SD] I% was 21.2 [6.13]% for groups 1 + 2, 39.47 [9.71]% for groups 3 + 4, 40.98 [11.76]% for group-5, and 35.01 [7.58]% for group-6 (ANOVA p < .0001; groups "1 + 2" versus "3 + 4" adj-p < .0001, group "1 + 2" versus "5" adj-p < .0001, and groups "1 + 2" versus "6" adj-p = .002). CONCLUSION: Iodine density obtained from dsDECTE significantly differed among CD phenotypes defined by SAR-AGA, with I (mg/mL) increasing with phenotype severity and decreasing for penetrating disease. I and I% can be used to phenotype CD.

Outcomes of Complex Endovascular Treatment of Post-Dissection Aneurysms.

OBJECTIVE: Reports of endovascular treatment of chronic post-dissection aneurysms are limited to high volumes centres, posing questions about generalisability. METHODS: All endovascular repairs of intact pararenal and thoraco-abdominal aneurysms in the Vascular Quality Initiative from 2014 to 2021 were studied, and peri-operative and long term outcomes were compared between repairs of degenerative and post-dissection aneurysms. Peri-operative outcomes were compared using mixed effects logistic regression, and long term outcomes using Medicare linkage. RESULTS: There were 123 patients who completed treatment for post-dissection aneurysms and 3 635 for degenerative aneurysms, with 36% of post-dissection repairs and 6.7% of degenerative repairs performed in a staged fashion (p < .001). The majority (84%) of post-dissection aneurysms were extensive thoraco-abdominal aneurysms (TAAAs: Crawford Type 1, 2, 3, 5), compared with 22% of degenerative aneurysms (p < .001). Physician modified endografts were the primary repair type for post-dissection (73%), while commercially available fenestrated grafts were the dominant repair for degenerative (48%). The first stage of staged procedures was associated with a 2.8% peri-operative mortality rate, 5.1% spinal cord ischaemia, and 8.9% thoraco-abdominal life altering events (the composite of peri-operative death, stroke, permanent spinal cord ischaemia, and dialysis). Th final stage procedure and fluoroscopy times were similar, but technical success was lower in post-dissection repairs (75% vs. 83%, p = .018), both due to issues with the main endograft or bridging vessels (11% vs. 6.6%, p = .055), and types 1and 3 endoleak at completion (17% vs. 10%, p = .035). In addition, high volume surgeons had two fold higher odds of technical success than their low volume counterparts. Adjusted peri-operative outcomes were similar between pathology types, including when comparisons were restricted to extensive TAAAs. Crude and adjusted three year survival were similar, but three year re-interventions were significantly higher following post-dissection repairs (p < .001). CONCLUSION: Complex endovascular repair of chronic post-dissection aneurysms is feasible but is associated with high rates of re-interventions and non-trivial rates of lack of technical success. More data are needed to evaluate the long term durability of these procedures, and the utility of centralising these complex procedures.

Compression therapy in peripheral artery disease: a literature review.

OBJECTIVE: Our objective is to examine the pathophysiology of oedema in the ischaemic and post-revascularised limb, compare compression stockings to pneumatic compression devices, and summarise compression regimens in patients with severe peripheral artery disease (PAD) without revascularisation, after revascularisation, and in mixed arterial and venous disease. METHOD: A scoping literature review of the aforementioned topics was carried out using PubMed. RESULTS: Compression therapy has been shown to increase blood flow and aid in wound healing through a variety of mechanisms. Several studies suggest that intermittent pneumatic compression (IPC) devices can be used to treat critical limb ischaemia in patients without surgical options. Additionally, compression stockings may have a role in preventing oedema after peripheral artery bypass surgery, thereby diminishing pain and reducing the risk of surgical wound dehiscence. CONCLUSION: Oedema may occur in the ischaemic limb after revascularisation surgery, as well as in combination with venous disease. Clinicians should not fear using compression therapy in PAD.

Asian race is associated with peripheral arterial disease severity and postoperative outcomes.

OBJECTIVE: The nature of peripheral arterial disease and postoperative outcomes are understudied in Asian patients. We aimed to determine if there are disparities in disease severity at the time of presentation and postoperative outcomes with regard to Asian race. METHODS: We analyzed the Society for Vascular Surgery Vascular Quality Initiative Peripheral Vascular Intervention dataset from 2017 to 2021, which includes endovascular lower extremity interventions. Propensity scores were used to match White and Asian patients based on age, sex, comorbidities, ambulatory/functional status, and intervention level. Differences were examined with regard to Asian race across all patients in the United States, Canada, and Singapore, and separately in the United States and Canada only. The primary outcome was emergent intervention. We also examined differences in severity of disease and postoperative outcomes. RESULTS: A total of 80,312 White and 1689 Asian patients underwent peripheral vascular intervention. After propensity score matching, we identified 1669 matched pairs of patients across all centers including Singapore and 1072 matched pairs in the United States and Canada only. Among the matched cohort consisting of all centers, Asian patients had a higher rate of emergent intervention to prevent limb loss (5.6% vs 1.7%, P < .001). The majority of Asian patients presented with chronic limb threatening ischemia at a higher rate than White patients within the cohort including Singapore (71% vs 66%, P = .005). Within both propensity-matched cohorts, the rate of in-hospital death was higher in Asian patients (all centers: 3.1% vs 1.2%, P < .001; United States and Canada only: 2.1% vs 0.8%, P = .010). Logistic regression demonstrated greater odds of emergent intervention in Asian patients from all centers including Singapore (odds ratio [OR], 3.3; 95% confidence interval [CI], 2.2-5.1, P < .001) but not in the United States and Canada only (OR, 1.4; 95% CI, 0.8-2.8, P = .261). In addition, Asian patients had greater odds of in-hospital death in both matched cohorts (all centers: OR, 2.6; 95% CI, 1.5-4.4, P < .001; United States and Canada: OR, 2.5; 95% CI, 1.1-5.8, P = .026). Asian race was associated with a greater risk of loss of primary patency at 18 months (all centers: hazard ratio, 1.5; CI, 1.2-1.8, P = .001; United States and Canada only: hazard ratio, 1.5; CI, 1.2-1.9, P = .002). CONCLUSIONS: Asian patients are more likely to present with advanced peripheral arterial disease and undergo emergent intervention to prevent limb loss, in addition to having worse postoperative outcomes and long-term patency. These results highlight the need for improved screening and postoperative follow-up in this understudied population.

Mortality analysis of endovascular aneurysm sealing versus endovascular aneurysm repair.

BACKGROUND: Endovascular aneurysm sealing (EVAS), using the Nellix endovascular aneurysm sealing system, has been associated with high reintervention and migration rates. However, prior reports have suggested that EVAS might be related to a lower all-cause mortality compared with endovascular aneurysm repair (EVAR). In the present study, we examined the 5-year all-cause mortality trends after EVAS and EVAR. METHODS: We compared the 333 EVAS patients in the EVAS-1 Nellix U.S. investigational device exemption trial with 16,497 infrarenal EVAR controls from the Vascular Quality Initiative, treated between 2014 and 2016, after applying the exclusion criteria from the investigational device exemption trial (ie, hemodialysis, creatinine >2.0 mg/dL, rupture). As a secondary analysis, we stratified the patients by aneurysm diameter (<5.5 cm and ≥5.5 cm). We calculated propensity scores after adjusting for demographics, comorbidities, and anatomic characteristics and applied inverse probability weighting to compare the risk-adjusted long-term mortality using Kaplan-Meier and Cox regression analyses. RESULTS: After weighting, the EVAS group had experienced similar 5-year mortality compared with the controls from the Vascular Quality Initiative (EVAS vs EVAR, 18% vs 14%; hazard ratio [HR], 1.1; 95% confidence interval [CI], 0.71-1.7; P = .70). The subgroup analysis demonstrated that for patients with an aneurysm diameter of <5.5 cm, EVAS was associated with higher 5-year mortality compared with EVAR (19% vs 11%; HR, 2.4; 95% CI, 1.7-4.7; P = .013). In patients with an aneurysm diameter of ≥5.5 cm, EVAS was associated with lower mortality within the first 2 years (2-year mortality: HR, 0.29; 95% CI, 0.13-0.62; P = .002). However, compared with EVAR, EVAS was associated with higher mortality between 2 and 5 years (HR, 1.9; 95% CI, 1.2-3.0; P = .005), with no mortality difference at 5 years (18% vs 17%; HR, 0.82; 95% CI, 0.4-1.4; P = .46). CONCLUSIONS: Within the overall population, EVAS was associated with similar 5-year mortality compared with EVAR. EVAS was associated with higher mortality for those with small aneurysms (<5.5 cm). For those with larger aneurysms (≥5.5 cm), EVAS was initially associated with lower mortality within the first 2 years, although this advantage was lost thereafter, with higher mortality after 2 years. Future studies are required to evaluate the specific causes of death and to elucidate the potential beneficial mechanism behind sac obliteration that leads to this potential initial survival benefit. This could help guide the development of future grafts with better proximal fixation and sealing that also incorporate sac obliteration.

Racial disparities in treatment of ruptured abdominal aortic aneurysms.

OBJECTIVE: The Society for Vascular Surgery has recommended immediate transfer of patients with ruptured abdominal aortic aneurysms (rAAAs) to a regional center when feasible. However, Black patients might be less likely to be transferred and more likely to be turned down for repair. We, therefore, examined the transfer rates, turndown rates, and outcomes for Black vs White patients presenting with rAAAs in two large databases. METHODS: We examined all rAAA repairs in the Vascular Quality Initiative from 2003 to 2020 to evaluate the transfer rates and outcomes for Black vs White patients. We used the National Inpatient Sample from 2004 to 2015 to examine the turndown rates. Mixed effects logistic regression, Cox regression, and marginal effects modeling were used to study the interaction between race, insurance status, surgery type (open repair vs endovascular aortic aneurysm repair), and hospital volume. RESULTS: We identified 4935 patients with rAAAs in the Vascular Quality Initiative (6.2% Black) and 48,489 in the National Inpatient Sample (6.0% Black). The rates of transfer were high; however, Black patients were significantly less likely to undergo transfer before repair compared with White patients (49% Black vs 62% White; P = .002). The result was consistent in both crude and adjusted analyses when considering only stable patients and was not modified by insurance status, surgery type, or hospital volume. No significant differences were found in perioperative mortality (22% vs 26%; P = .098) or complications (52% vs 52%; P = .64). However, Black patients were significantly more likely to be turned down for repair (37% vs 28%; odds ratio, 1.5; 95% confidence interval, 1.2-1.9; P < .001). A significant interaction was found between race and insurance status with respect to turndown. Patients with private insurance had undergone surgery at a similar rate, regardless of race. However, among patients with Medicare or Medicaid/self-pay, Black patients were less likely than were White patients to undergo repair (Medicare, 64% vs 72%; P = .001; Medicaid/self-pay, 43% vs 61%; P = .031). Patients with Medicaid/self-pay were also less likely to undergo repair than were patients of the same race with either Medicare or private insurance (P < .05). CONCLUSIONS: We found that Black patients with rAAAs are poorly served by the current systems of interhospital transfer in the United States, because they less often undergo transfer before repair. Although the postoperative outcomes appeared similar, this finding could be falsely optimistic, because Black patients, especially the underinsured, were turned down for repair more often even after adjustment. Significant work is needed to better understand the reasons underlying these disparities and identify the targets to improve the care of Black patients with rAAAs.