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 2003-2021. 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. Chi-square 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 1,766 Asian and 159,608 White patients underwent carotid revascularization and we identified 2,704 patients (1,352 Asian and 1,352 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 (OR, 0.3; CI, 0.2-0.3; P<.001) and by highest volume surgeons (OR, 0.3; CI, 0.3-0.4; P<.001). Asian race was associated with higher odds of in-hospital stroke/death/myocardial infarction (OR, 2.0; 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; CI, 0.7-3.3; P=.300). Cox regression between the matched cohorts demonstrated that Asian race was associated with lower 1-year mortality (HR, 0.5; CI, 0.3-0.7; P=.001) and higher risk of 1-year reintervention (HR, 16; CI, 1.8-142; P=.013). CONCLUSION: 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.

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.

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.

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.

Protocol optimization for abdominal imaging using photon-counting CT: a consensus of two academic institutions.

PURPOSE: Photon-counting detector CT (PCD CT) is a promising technology for abdominal imaging due to its ability to provide high spatial and contrast resolution images with reduced patient radiation exposure. However, there is currently no consensus regarding the optimal imaging protocols for PCD CT. This article aims to present the PCD CT abdominal imaging protocols used by two tertiary care academic centers in the United States. METHODS: A review of PCD CT abdominal imaging protocols was conducted by two abdominal radiologists at different academic institutions. Protocols were compared in terms of acquisition parameters and reconstruction settings. Both imaging centers independently selected similar protocols for PCD CT abdominal imaging, using QuantumPlus mode. RESULTS: There were some differences in the use of reconstruction kernels and iterative reconstruction levels, however the individual combination at each site resulted in similar image impressions. Overall, the imaging protocols used by both centers provide high-quality images with low radiation exposure. CONCLUSION: These findings provide valuable insights into the development of standardized protocols for PCD CT abdominal imaging, which can help to ensure consistent as well as high-quality imaging across different institutions and allow for future multicenter research collaborations.

The clinical and economic impact of chronic venous insufficiency-associated lymphedema and the prevalence of persistent edema after venous intervention.

OBJECTIVES: To determine the demographics, outcomes, and healthcare utilization of patients with chronic venous insufficiency-associated lymphedema (CVI-LED) and the prevalence of lymphedema-specific therapy use after venous intervention. METHODS: The IBM MarketScan Commercial and Medicare Claims Databases were examined for patients with CVI-LED. Patient demographics and the use of lymphedema-specific therapy before and after venous intervention were collected. RESULTS: Of 85,601 LED patients identified, 8,406 also had a diagnosis of CVI. In the CVI-LED group, 1051 underwent endovenous ablation or venous stent placement. The use of lymphedema-specific therapy before and after venous intervention was 52% and 39%, respectively (p < .05). The mean time of initiation of LED-specific therapy following venous intervention was 265 days after ablation and 347 days after stent placement. CONCLUSION: Treating venous hypertension improves certain venous-related signs and symptoms of CVI. However, a significant proportion of patients have persistent edema which may reflect underlying, sub-optimally treated LED.

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.

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.

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.

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.

Photon-Counting Computed Tomography Versus Energy-Integrating Dual-Energy Computed Tomography: Virtual Noncontrast Image Quality Comparison.

PURPOSE: This study aimed to compare the image quality of portal venous phase-derived virtual noncontrast (VNC) images from photon-counting computed tomography (PCCT) with energy-integrating dual-energy computed tomography (EI-DECT) in the same patient using quantitative and qualitative analyses. METHODS: Consecutive patients retrospectively identified with available portal venous phase-derived VNC images from both PCCT and EI-DECT were included. Patients without available VNC in picture archiving and communication system in PCCT or prior EI-DECT and non-portal venous phase acquisitions were excluded. Three fellowship-trained radiologists blinded to VNC source qualitatively assessed VNC images on a 5-point scale for overall image quality, image noise, small structure delineation, noise texture, artifacts, and degree of iodine removal. Quantitative assessment used region-of-interest measurements within the aorta at 4 standard locations, both psoas muscles, both renal cortices, spleen, retroperitoneal fat, and inferior vena cava. Attenuation (Hounsfield unit), quantitative noise (Hounsfield unit SD), contrast-to-noise ratio (CNR) (CNR vascular , CNR kidney , CNR spleen , CNR fat ), signal-to-noise ratio (SNR) (SNR vascular , SNR kidney , SNR spleen , SNR fat ), and radiation dose were compared between PCCT and EI-DECT with the Wilcoxon signed rank test. A P < 0.05 indicated statistical significance. RESULTS: A total of 74 patients (27 men; mean ± SD age, 63 ± 13 years) were included. Computed tomography dose index volumes for PCCT and EI-DECT were 9.2 ± 3.5 mGy and 9.4 ± 9.0 mGy, respectively ( P = 0.06). Qualitatively, PCCT VNC images had better overall image quality, image noise, small structure delineation, noise texture, and fewer artifacts (all P < 0.00001). Virtual noncontrast images from PCCT had lower attenuation (all P < 0.05), noise ( P = 0.006), and higher CNR ( P < 0.0001-0.04). Contrast-enhanced structures had lower SNR on PCCT ( P = 0.001, 0.002), reflecting greater contrast removal. The SNRfat (nonenhancing) was higher for PCCT than EI-DECT ( P < 0.00001). CONCLUSIONS: Virtual noncontrast images from PCCT had improved image quality, lower noise, improved CNR and SNR compared with those derived from EI-DECT.

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.

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.

Psychiatric risk gene Transcription Factor 4 (TCF4) regulates the density and connectivity of distinct inhibitory interneuron subtypes.

Transcription factor 4 (TCF4) is a basic helix-loop-helix transcription factor that is implicated in a variety of psychiatric disorders including autism spectrum disorder (ASD), major depression, and schizophrenia. Autosomal dominant mutations in TCF4 are causal for a specific ASD called Pitt-Hopkins Syndrome (PTHS). However, our understanding of etiological and pathophysiological mechanisms downstream of TCF4 mutations is incomplete. Single cell sequencing indicates TCF4 is highly expressed in GABAergic interneurons (INs). Here, we performed cell-type specific expression analysis (CSEA) and cellular deconvolution (CD) on bulk RNA sequencing data from 5 different PTHS mouse models. Using CSEA we observed differentially expressed genes (DEGs) were enriched in parvalbumin expressing (PV+) INs and CD predicted a reduction in the PV+ INs population. Therefore, we investigated the role of TCF4 in regulating the development and function of INs in the Tcf4+/tr mouse model of PTHS. In Tcf4+/tr mice, immunohistochemical (IHC) analysis of subtype-specific IN markers and reporter mice identified reductions in PV+, vasoactive intestinal peptide (VIP+), and cortistatin (CST+) expressing INs in the cortex and cholinergic (ChAT+) INs in the striatum, with the somatostatin (SST+) IN population being spared. The reduction of these specific IN populations led to cell-type specific alterations in the balance of excitatory and inhibitory inputs onto PV+ and VIP+ INs and excitatory pyramidal neurons within the cortex. These data indicate TCF4 is a critical regulator of the development of specific subsets of INs and highlight the inhibitory network as an important source of pathophysiology in PTHS.

Impact of lymphedema in the management of venous leg ulcers.

INTRODUCTION: Lymphedema (LED) in patients with venous leg ulcers (VLU) [VLU+LED] can impair ulcer healing and predispose to cellulitis. There is little data, however, demonstrating how lymphatic dysfunction may impact the clinical course, treatment, and healthcare expenditures for VLU+LED versus VLU-LED patients. OBJECTIVE: To determine how lymphatic dysfunction might influence treatment and expenditures among VLU patients in a large deidentified healthcare claims database. METHODS: A retrospective cohort design and data from the IBM MarketScan Database (April 2013 to March 2019) were employed. Study population comprised VLU patients, and was stratified into two subgroups: VLU+LED (index date = date of first LED diagnosis) and VLU-LED (index dates randomly assigned to match distribution of index dates for VLU+LED). Within each subgroup, patients with <1 year of healthcare claims information before and after their index dates were excluded. Demographics, comorbidities, procedures/treatments, as well as all-cause post-index medical resource utilization and expenditures ($/patient/year) of the two groups were compared. Stabilized inverse probability treatment weights (IPTWs) were employed to adjust for differences between groups in baseline characteristics. RESULTS: A total of 5466 VLU patients were identified (VLU+LED: N = 299; VLU-LED: N = 5167). Overall ambulatory encounters (AMB ENC) and their components were higher in VLU+LED, which were reflected in increased expenditures for this group (Table 1). Treatment with endovenous ablation (EVA) or stenting for venous hypertension as well as for specific measures for LED were higher in the 1-year post-index period for VLU+LED. The use of LED specific therapy was low for both groups, but a greater percentage of VLU+LED patients received therapy, which was predominantly manual lymphatic drainage (17.4%) rather than pneumatic compression (10.7%). CONCLUSIONS: The clinical presence of LED in patients with VLU is a marker for a more complex disease process with more episodes of cellulitis and expenditures, but a surprisingly low specific treatment for LED.

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.