High Prevalence of Adverse Social Determinants of Health in Dialysis Access Creation Patients in a Safety-Net Setting.

BACKGROUND: Patients receiving dialysis access surgery are often exposed to adverse social determinants of health (SDH) that negatively impact their care. Our goal was to characterize these factors experienced by our arteriovenous dialysis access patients and identify differences in health outcomes based on their SDH. METHODS: We performed a retrospective cohort study of all patients who underwent dialysis access creation (2017-2021) and were screened for SDH at a clinical visit (using THRIVE survey) implemented at an urban, safety-net hospital institution within 1 year of access creation. Demographics, procedural details, early postoperative outcomes, survey responses, and referral to our hospital's preventive food pantry were recorded. Univariable analysis and multivariable analyses were performed to assess for associations with key health outcomes. RESULTS: There were 190 patients who responded to the survey within 1 year of their operation. At least 1 adverse SDH was identified in 42 (22%) patients. Normalized to number of respondents for each question, adverse SDH identified were difficulty obtaining transportation to medical appointments (18%), food insecurity (16%), difficulty affording utilities (13%), difficulty affording medication (12%), unemployed and seeking employment (9%), unstable housing (7%), difficulty caring for family/friends (6%), and desiring more education (5%). There were 71 (37%) patients who received food pantry referrals. Mean age was 60 years and 38% of patients were female and 64% were Black. More than half of patients (57%) had a tunneled dialysis catheter (TDC) at the time of access creation. Dialysis accesses created were brachiocephalic (39%), brachiobasilic (25%), radiocephalic fistulas (16%), and arteriovenous grafts (14%). Thirty-day emergency department (ED) visits, 30-day readmissions, and 90-day mortality occurred in 23%, 21%, and 2%, respectively. On univariable and multivariable analyses, any adverse SDH determined on survey and food pantry referral were not associated with preoperative dialysis through TDCs, receiving nonautogenous dialysis access, 30-day ED visits and readmissions, or 90-day mortality. CONCLUSION: Nearly a quarter of dialysis access surgery patients at a safety-net hospital experienced adverse SDH and more than one-third received a food pantry referral. Most common difficulties experienced include difficulty obtaining transportation to medical appointments, food insecurity, and difficulty paying for utilities and medication. Although there were no differences in postoperative outcomes, the high prevalence of these adverse SDH warrants prioritization of resources in this population to ensure healthy equity and further investigation into their effects on health outcomes.

Analysis of Early Death after Elective Open Abdominal Aortic Aneurysm Repair.

BACKGROUND: Mortality after open abdominal aortic aneurysm repair is a quality measure and early death may represent a technical complication or poor patient selection. Our objective was to analyze patients who died in the hospital within postoperative day (POD) 0-2 after elective abdominal aortic aneurysm repair. METHODS: The Vascular Quality Initiative was queried from 2003-2019 for elective open abdominal aortic aneurysm repairs. Operations were categorized as in-hospital death on POD 0-2 (POD 0-2 Death), in-hospital death beyond POD 2 (POD ≥3 Death), and those alive at discharge. Univariable and multivariable analyses were performed. RESULTS: There were 7,592 elective open abdominal aortic aneurysm repairs with 61 (0.8%) POD 0-2 Death, 156 (2.1%) POD ≥3 Death, and 7,375 (97.1%) alive at discharge. Overall, median age was 70 years and 73.6% were male. Iliac aneurysm repair and surgical approach (anterior/retroperitoneal) were similar among groups. POD 0-2 Death, compared to POD ≥3 Death and those alive at discharge, had the longest renal/visceral ischemia time, more commonly had proximal clamp placement above both renal arteries, an aortic distal anastomosis, longest operative time, and largest estimated blood loss (all P < 0.05). Postoperative vasopressor usage, myocardial infarction, stroke, and return to the operating room were most frequent in POD 0-2 Death and extubation in the operating room was least frequent (all P < 0.001). Postoperative bowel ischemia and renal failure occurred most commonly among POD ≥3 Death (all P < 0.001).On multivariable analysis, POD 0-2 Death was associated with congestive heart failure, prior peripheral vascular intervention, female sex, preoperative aspirin use, lower center volume quartile, renal/visceral ischemia time, estimated blood loss, and older age (all P < 0.05). CONCLUSIONS: POD 0-2 Death was associated with comorbidities, center volume, renal/visceral ischemia time, and estimated blood loss. Referral to high-volume aortic centers could improve outcomes.

Access site complications are uncommon with vascular closure devices or manual compression after lower extremity revascularization.

OBJECTIVE: Vascular closure devices (VCDs) and manual compression (MC) are used to achieve hemostasis after peripheral vascular interventions (PVIs). We sought to compare perioperative outcomes between MC and four VCDs after PVI in a multicenter setting. METHODS: The Vascular Quality Initiative was queried for all lower extremity PVIs with common femoral artery access performed from 2010 to 2020. The VCDs included were MynxGrip (Cordis, Santa Clara, CA), StarClose SE (Abbott Vascular, Redwood City, CA), Angio-Seal (Terumo, Somerset, NJ), and Perclose ProGlide (Abbott Vascular). In a blinded fashion, these four VCDs (labeled A, B, C, and D) were compared to MC for baseline characteristics, procedural details, and outcomes (access site hematoma and stenosis/occlusion). Those with a sheath size >8F were excluded. Propensity score matching (1:1) was performed. Univariable and multivariable analyses were completed for unmatched and matched data. RESULTS: A total of 84,172 lower extremity PVIs were identified. Of these, 32,013 (38%) had used MC and 52,159 (62%) had used VCDs (A, 12,675; B, 6224; C, 19,872; D, 13,388). The average age was 68.7 years, and 60.4% of the patients were men. The most common indications for intervention were claudication (43.8%) and tissue loss (40.1%). Compared with MC, VCDs were used more often for patients with obesity, diabetes, and end-stage renal disease (P < .001 for all). VCDs were used less often for patients with hypertension, chronic obstructive pulmonary disease, coronary artery disease, prior percutaneous coronary and extremity interventions, and major amputation (P < .001 for all). VCD use was more common than MC during femoropopliteal (73% vs 63.8%) and tibial (33.8% vs 22.3%) interventions but less common with iliac interventions (20.6% vs 34.7%; P < .001 for all). Protamine was used less often with VCDs (19.1% vs 25.6%; P < .001). Overall, 2003 hematomas had developed (2.4%), of which 278 (13.9%) had required thrombin or surgical intervention. Compared with MC, the use of any VCD had resulted in fewer hematomas (1.7% vs 3.6%; P < .001) and fewer hematomas requiring intervention (0.2% vs 0.5%; P < .001). When divided by hemostatic technique, the rate of the development of any hematoma was as follows: MC, 3.6%; VCD A, 1.4%; VCD B, 1.2%; VCD C, 2.3%; and VCD D, 1.1% (P < .001). The rate of hematomas requiring intervention was as follows: MC, 0.5%; VCD A, 0.2%; VCD B, 0.2%; VCD C, 0.3%; and VCD D, 0.1% (P < .001). Access site stenosis/occlusion was similar between the MC and any VCD groups (0.2% vs 0.2%; P = .12). Multivariable analysis demonstrated that any VCD use and the use of the individual VCDs compared with MC were independently associated with the development of fewer hematomas. The incidence of access site stenosis/occlusion was similar between the use of any VCD and MC. The matched analysis revealed similar findings. CONCLUSIONS: Although the overall rates of hematomas requiring intervention were low regardless of hemostatic technique, VCD use, irrespective of type, compared favorably with MC, with significantly fewer access site complications after PVI.

Indoleamine 2,3-dioxygenase-1, a Novel Therapeutic Target for Post-Vascular Injury Thrombosis in CKD.

BACKGROUND: CKD, characterized by retained uremic solutes, is a strong and independent risk factor for thrombosis after vascular procedures . Urem ic solutes such as indoxyl sulfate (IS) and kynurenine (Kyn) mediate prothrombotic effect through tissue factor (TF). IS and Kyn biogenesis depends on multiple enzymes, with therapeutic implications unexplored. We examined the role of indoleamine 2,3-dioxygenase-1 (IDO-1), a rate-limiting enzyme of kynurenine biogenesis, in CKD-associated thrombosis after vascular injury. METHODS: IDO-1 expression in mice and human vessels was examined. IDO-1-/- mice, IDO-1 inhibitors, an adenine-induced CKD, and carotid artery injury models were used. RESULTS: Both global IDO-1-/- CKD mice and IDO-1 inhibitor in wild-type CKD mice showed reduced blood Kyn levels, TF expression in their arteries, and thrombogenicity compared with respective controls. Several advanced IDO-1 inhibitors downregulated TF expression in primary human aortic vascular smooth muscle cells specifically in response to uremic serum. Further mechanistic probing of arteries from an IS-specific mouse model, and CKD mice, showed upregulation of IDO-1 protein, which was due to inhibition of its polyubiquitination and degradation by IS in vascular smooth muscle cells. In two cohorts of patients with advanced CKD, blood IDO-1 activity was significantly higher in sera of study participants who subsequently developed thrombosis after endovascular interventions or vascular surgery. CONCLUSION: Leveraging genetic and pharmacologic manipulation in experimental models and data from human studies implicate IS as an inducer of IDO-1 and a perpetuator of the thrombotic milieu and supports IDO-1 as an antithrombotic target in CKD.

Haploinsufficiency of Casitas B-Lineage Lymphoma Augments the Progression of Colon Cancer in the Background of Adenomatous Polyposis Coli Inactivation.

Casitas B-lineage lymphoma (c-Cbl) is a recently identified ubiquitin ligase of nuclear ß-catenin and a suppressor of colorectal cancer (CRC) growth in cell culture and mouse tumor xenografts. We hypothesized that reduction in c-Cbl in colonic epithelium is likely to increase the levels of nuclear ß-catenin in the intestinal crypt, augmenting CRC tumorigenesis in an adenomatous polyposis coli (APCΔ14/+) mouse model. Haploinsufficient c-Cbl mice (APCΔ14/+ c-Cbl+/-) displayed a significant (threefold) increase in atypical hyperplasia and adenocarcinomas in the small and large intestines; however, no differences were noted in the adenoma frequency. In contrast to the APCΔ14/+ c-Cbl+/+ mice, APCΔ14/+ c-Cbl+/- crypts showed nuclear ß-catenin throughout the length of the crypts and up-regulation of Axin2, a canonical Wnt target gene, and SRY-box transcription factor 9, a marker of intestinal stem cells. In contrast, haploinsufficiency of c-Cbl+/- alone was insufficient to induce tumorigenesis regardless of an increase in the number of intestinal epithelial cells with nuclear ß-catenin and SRY-box transcription factor 9 in APC+/+ c-Cbl+/- mice. This study demonstrates that haploinsufficiency of c-Cbl results in Wnt hyperactivation in intestinal crypts and accelerates CRC progression to adenocarcinoma in the milieu of APCΔ14/+, a phenomenon not found with wild-type APC. While emphasizing the role of APC as a gatekeeper in CRC, this study also demonstrates that combined partial loss of c-Cbl and inactivation of APC significantly contribute to CRC tumorigenesis.

Metabolites in a mouse cancer model enhance venous thrombogenicity through the aryl hydrocarbon receptor-tissue factor axis.

Patients with malignancy are at 4- to 7-fold higher risk of venous thromboembolism (VTE), a potentially fatal, yet preventable complication. Although general mechanisms of thrombosis are enhanced in these patients, malignancy-specific triggers and their therapeutic implication remain poorly understood. Here we examined a colon cancer-specific VTE model and probed a set of metabolites with prothrombotic propensity in the inferior vena cava (IVC) ligation model. Athymic mice injected with human colon adenocarcinoma cells exhibited significantly higher IVC clot weights, a biological readout of venous thrombogenicity, compared with the control mice. Targeted metabolomics analysis of plasma of mice revealed an increase in the blood levels of kynurenine and indoxyl sulfate (tryptophan metabolites) in xenograft-bearing mice, which correlated positively with the increase in the IVC clot size. These metabolites are ligands of aryl hydrocarbon receptor (AHR) signaling. Accordingly, plasma from the xenograft-bearing mice activated the AHR pathway and augmented tissue factor (TF) and plasminogen activator inhibitor 1 (PAI-1) levels in venous endothelial cells in an AHR-dependent manner. Consistent with these findings, the endothelium from the IVC of xenograft-bearing animals revealed nuclear AHR and upregulated TF and PAI-1 expression, telltale signs of an activated AHR-TF/PAI-1 axis. Importantly, pharmacological inhibition of AHR activity suppressed TF and PAI-1 expression in endothelial cells of the IVC and reduced clot weights in both kynurenine-injected and xenograft-bearing mice. Together, these data show dysregulated tryptophan metabolites in a mouse cancer model, and they reveal a novel link between these metabolites and the control of the AHR-TF/PAI-1 axis and VTE in cancer.

Intravenous drug use history is not associated with poorer outcomes after arteriovenous access creation.

OBJECTIVE: Rising intravenous drug use (IVDU) paralleled with an increasing dialysis-dependent end-stage renal disease population may pose a challenge for creating and maintaining arteriovenous (AV) access for hemodialysis. We aimed to elucidate baseline characteristics and outcomes of AV access creation in the IVDU population. METHODS: The Vascular Quality Initiative (2011-2018) was queried for patients undergoing AV access placement. Univariable and multivariable analyses comparing outcomes of patients with and without IVDU history were performed. RESULTS: Of 33,404 patients undergoing AV access creation, 601 (1.8%) had IVDU history (21.8% current and 78.2% past users). IVDU patients receiving AV access were more often younger, male, nonwhite, smokers, homeless, Medicaid recipients, and hospitalized at the time of surgery (P < .001 for all). They exhibited higher rates of congestive heart failure, chronic obstructive pulmonary disease, and human immunodeficiency virus/acquired immunodeficiency syndrome (P < .05 for all). They more frequently had tunneled catheters at the time of access creation (53.6% vs 42%; P < .001) and had a previous AV access (25.3% vs 21.7%; P = .002). IVDU patients more often received prosthetic AV grafts (28.6% vs 18%; P < .001) and more often had anastomoses created to basilic veins (33.1% vs 23.2%; P < .001) but less often to cephalic veins (36.8% vs 57.7%; P < .001). IVDU patients had longer postoperative length of stay (2 ± 6 days vs 0.9 ± 5 days; P < .001) but no significant difference in 30-day mortality (1.7% vs 1.2%; P = .3). Comparing IVDU vs no IVDU cohorts, 1-year access infection-free survival (85.4% vs 86.6%; P = .382), primary patency loss-free survival (39.5% vs 37.9%; P = .335), endovascular/open reintervention-free survival (58% vs 57%; P = .705), and overall survival (89.7% vs 88.9%; P = .635) were similar. On multivariable analysis, IVDU was independently associated with postoperative length of stay (odds ratio, 1.64; 95% confidence interval, 1.35-2; P < .001) but not with 30-day mortality or 1-year infection-free survival, primary patency loss-free survival, reintervention-free survival, and all-cause mortality. The null results were confirmed in a propensity score-matched cohort. CONCLUSIONS: IVDU history was uncommon among patients undergoing AV access creation at Vascular Quality Initiative centers and was not independently associated with major morbidity or mortality postoperatively. IVDU patients more often received grafts or autogenous access with anastomoses to basilic veins. Although these patients frequently have more comorbidities, IVDU should not deter AV access creation.

The Association of Body Mass Index with Outcomes after Carotid Endarterectomy.

BACKGROUND: Patients who are obese or underweight are traditionally at higher risk for perioperative morbidity and mortality. The effect of body mass index (BMI) on outcomes after carotid endarterectomy (CEA) is unclear. Our goal was to analyze the association of BMI with perioperative and long-term outcomes after elective CEA. METHODS: The Vascular Quality Initiative (VQI) database was queried from 2003-2018 for patients undergoing elective CEAs. Patients were categorized into 5 BMI cohorts - underweight (UW, BMI < 18.5 kg/m2), normal weight (NW, BMI 18.5-24.9 kg/m2), overweight (OW, BMI 25-29.9 kg/m2), obese (OB, BMI 30-39.9 kg/m2), and morbidly obese (MO, BMI ≥ 40 kg/m2). Perioperative and long-term outcomes were assessed with univariable and multivariable analyses. RESULTS: There were 89,079 patients included: 2% UW, 26% NW, 38.4% OW, 29.9% OB, and 3.6% MO. Overall, the mean age was 70.6 years, 60% were male, and 91.8% were of white race. There were significant differences among the BMI cohorts in regards to age, sex, smoking status, and comorbidities (all P < 0.05). For perioperative outcomes, the BMI cohorts differed significantly in reoperation for bleeding and 30-day mortality. On multivariable analysis, BMI was not associated with stroke or perioperative mortality. MO was associated with perioperative cardiac complications (Odds Ratios [OR] 1.26, 95% CI 1-1.57, P = 0.05). UW status was associated with increased return to the operating room (OR 1.89, 95% confidence interval [95% CI] 1.28-2.78, P = 0.001), 30-day mortality (OR 1.68, 95% CI 1-2.86, P =0.05), 1-year mortality (Hazard ratio [HR] 1.37, 95% CI 1.08-1.74, P = 0.01), and 5-year mortality (HR 1.22, 95% CI 1.06-1.41, P =0.005). CONCLUSIONS: BMI status was not associated with perioperative stroke, cranial nerve injury, or surgical site infections. Patients with MO had higher perioperative cardiac complications. UW patients have lower short and long-term survival and should be a focus for long-term targeted risk factor stratification and modification.

Periprocedural Outcomes in Patients on Chronic Anticoagulation Undergoing Fistulograms.

BACKGROUND: Management of antithrombotic therapy with warfarin in patients undergoing fistulograms and possible interventions is controversial and difficult because of lack of adequate outpatient bridging options. Our goal was to assess periprocedural outcomes in patients managed using different anticoagulation strategies. METHODS: A retrospective, single-institution analysis of all patients on chronic anticoagulation with warfarin undergoing fistulograms from 2011 to 2017 was performed. Anticoagulation management strategies were classified as suspended warfarin (SW), continued warfarin (CW), and a heparin bridge with suspended warfarin (HB). Periprocedural outcomes were analyzed. RESULTS: There were 87 patients on chronic anticoagulation with warfarin who underwent 175 fistulograms. Median age was 63 years, and 43.4% were women. Indications for warfarin included atrial fibrillation (53%), prior pulmonary embolism/deep vein thrombosis (29%), and hypercoagulable state (14%). Distribution was SW (60%), CW (26%), and HB (14%). Approximately half (53%) were same-day procedures, 30% occurred during access-related admissions, and 14% were performed during nonaccess-related admissions. Common indications for a fistulogram included difficulty with dialysis (63.4%), access thrombosis (20.6%), and poor maturation (10.3%). Interventions included angioplasty (82.9%), thrombectomy/embolectomy (20.6%), and stenting (8.6%). Thirty-day outcomes for SW versus CW versus HB were similar for bleeding complications (5.7%, 6.5%, 8.3%; P = 0.89), systemic thrombotic complications (3.8%, 2.2%, 0%; P = 0.569), access rethrombosis (7.6%, 13%, 12.5%; P = 0.517), and tunneled dialysis catheter placement (11.4%, 13%, 12.5%; P = 0.958). After excluding procedures performed during a nonaccess-related admission, length of stay (LOS) was highest among HB (9.6 ± 7.8 days) compared with SW (2.6 ± 5.9 days) and CW (1 ± 2.8 days), (P < 0.0001). CONCLUSIONS: CW therapy in patients undergoing fistulograms was not associated with increased morbidity and was associated with shorter LOS. Bridging with heparin is not associated with improved outcomes, warranting a thorough consideration of continuing warfarin is safe and may streamline preservation of dialysis accesses without significantly increasing resource utilization.

Temporal and tissue-specific activation of aryl hydrocarbon receptor in discrete mouse models of kidney disease.

Emerging evidence in animal models of chronic kidney disease (CKD) implicates Aryl Hydrocarbon Receptor (AHR) signaling as a mediator of uremic toxicity. However, details about its tissue-specific and time-dependent activation in response to various renal pathologies remain poorly defined. Here, a comprehensive analysis of AHR induction was conducted in response to discrete models of kidney diseases using a transgenic mouse line expressing the AHR responsive-promoter tethered to a ß-galactosidase reporter gene. Following validation using a canonical AHR ligand (a dioxin derivative), the transgenic mice were subjected to adenine-induced and ischemia/reperfusion-induced injury models representing CKD and acute kidney injury (AKI), respectively, in humans. Indoxyl sulfate was artificially increased in mice through the drinking water and by inhibiting its excretion into the urine. Adenine-fed mice showed a distinct and significant increase in ß-galactosidase in the proximal and distal renal tubules, cardiac myocytes, hepatocytes, and microvasculature in the cerebral cortex. The pattern of ß-galactosidase increase coincided with the changes in serum indoxyl sulfate levels. Machine-learning-based image quantification revealed positive correlations between indoxyl sulfate levels and ß-galactosidase expression in various tissues. This pattern of ß-galactosidase expression was recapitulated in the indoxyl sulfate-specific model. The ischemia/reperfusion injury model showed increase in ß-galactosidase in renal tubules that persisted despite reduction in serum indoxyl sulfate and blood urea nitrogen levels. Thus, our results demonstrate a relationship between AHR activation in various tissues of mice with CKD or AKI and the levels of indoxyl sulfate. This study demonstrates the use of a reporter gene mouse to probe tissue-specific manifestations of uremia in translationally relevant animal models and provide hypothesis-generating insights into the mechanism of uremic toxicity that warrant further investigation.

Risk assessment of significant upper extremity arteriovenous graft infection in the Vascular Quality Initiative.

OBJECTIVE: Infectious complications of arteriovenous grafts (AVGs) are a major source of morbidity. Our aim was to characterize contemporary risk factors for upper extremity AVG infection. METHODS: The Vascular Quality Initiative (2011-2018) was queried for all patients undergoing upper extremity AVG creation. AVG infection was classified as an infection treated with antibiotics, incision and drainage, or graft removal. Multivariable analyses were used to evaluate risk factors for short- and long-term AVG infection. RESULTS: Of 1758 upper extremity AVGs, 49 (2.8%) developed significant infection within 3 months, resulting in incision and drainage in 24% and graft removal in 76% of cases. None were managed with antibiotics alone in the study sample. Patients with significant AVG infection were more likely to be white, to be insured, to have a history of coronary artery bypass graft and intravenous (IV) drug use, to be undergoing a concomitant vascular procedure, and to be discharged on an anticoagulant. In multivariable analysis, significant AVG infection within 3 months was associated with IV drug use history (odds ratio [OR], 5; 95% confidence interval [CI], 1.75-14.3; P = .003), discharge to a health care facility (OR, 2.66; 95% CI, 1.07-6.63; P = .035), discharge on an anticoagulant (OR, 2.31; 95% CI, 1.13-4.72; P = .021), white race (OR, 2.3; 95% CI, 1.21-4.34; P = .011), and female sex (OR, 2.02; 95% CI, 1.06-3.85; P = .033). Kaplan-Meier analysis showed that freedom from graft site infection at 1 year was 96.4%. Longer term graft infection at 1 year was independently associated with IV drug use history (hazard ratio [HR], 1.98; 95% CI, 1.06-3.68; P = .032), initial discharge to a health care facility (HR, 1.88; 95% CI, 1.19-2.97; P = .007), and white race (HR, 1.64; 95% CI, 1.23-2.19; P = .001). CONCLUSIONS: Although significant AVG infection was uncommon in the Vascular Quality Initiative, the majority were treated with graft removal. In select high-risk patients, extra care should be taken and alternative forms of arteriovenous access may be considered.

Patients undergoing interventions for claudication experience low perioperative morbidity but are at risk for worsening functional status and limb loss.

OBJECTIVE: Interventional approaches to managing intermittent claudication vary widely. According to Society for Vascular Surgery guidelines, any invasive treatment of claudication must offer long-term benefit at low risk of complications. Our aim was to evaluate contemporary claudication intervention patterns and functional outcomes. METHODS: The Vascular Study Group of New England database (2003-2018) was queried for peripheral vascular interventions (PVIs), infrainguinal bypasses, and suprainguinal bypasses for claudication. Perioperative and 1-year outcomes were evaluated. RESULTS: There were 7051 PVIs, 2527 infrainguinal bypasses, and 849 suprainguinal bypasses performed for claudication. Treatment levels were iliac (52.2%), femoral-popliteal (54%), and tibial (5.7%). Isolated tibial interventions were completed in 1.7% of patients. Infrainguinal bypasses were most often to the popliteal artery (81.2%); however, in 18.8% of cases, bypasses were to tibial targets. Suprainguinal bypasses originated primarily from the abdominal aorta (88.6%) but also from the axillary artery (10.6%) and thoracic aorta (0.8%). Common perioperative complications were access site hematoma in 4.9% of PVIs and cardiac complications in 3.7% of infrainguinal bypasses and 11.3% of suprainguinal bypasses. Overall, 30-day mortality was 0.4% to 2%. After 1 year, of patients initially ambulating without assistance, 2.4% to 3.6% required assistance and 0.3% to 1.3% were nonambulatory. Ipsilateral reintervention/amputation-free survival, major amputation-free survival, and survival at 1 year were 81.4% to 90.6%, 92.9% to 94.1%, and 95.3% to 97%, respectively. CONCLUSIONS: Multisegment PVI was the most commonly performed intervention for claudication; however, a subset of patients received treatments supported by limited evidence, including isolated tibial PVI and bypasses with axillary inflow and tibial outflow. Interventions had low perioperative morbidity and mortality, yet patients were still at risk for worse functional status and limb loss at 1 year, emphasizing the importance of careful patient selection, medical optimization, and informed consent.

Perioperative outcomes after lower extremity bypass and peripheral vascular interventions in patients with morbid obesity and superobesity.

OBJECTIVE: Although the effect of body mass index (BMI) on the treatment of infrainguinal peripheral artery disease has been reported, outcomes of patients on the upper end of the obesity spectrum, including morbid obesity (MO) and superobesity (SO), are unclear. Our goal was to analyze perioperative outcomes after lower extremity bypass (LEB) and peripheral vascular interventions (PVIs) in this population of patients. METHODS: The Vascular Quality Initiative was reviewed for all infrainguinal peripheral artery disease interventions from 2010 to 2017. All patients were categorized into four groups: nonobese (BMI 18.5-29.9 kg/m2), obese (BMI 30-39.9 kg/m2), morbidly obese (BMI 40-49.9 kg/m2), and superobese (BMI ≥50 kg/m2). Patient and case details were recorded. Multivariable analysis was used to analyze outcomes. For statistical analysis, MO and SO groups were combined. RESULTS: We identified 29,138 LEB cases (68.5% nonobese, 28.3% obese, 2.9% morbidly obese, 0.3% superobese) and 81,405 PVI cases (66.6% nonobese, 29.2% obese, 3.6% morbidly obese, 0.5% superobese). For both LEB and PVI, patients with MO and SO were more likely to be younger, female, nonsmokers, and ambulatory (P < .05). They also more often had diabetes, end-stage renal disease, congestive heart failure, and fewer previous inflow procedures (P < .05). LEB and PVI interventions in patients with MO and SO were less often elective and more often performed for tissue loss. Multivariable analysis showed that LEB in patients with MO and SO was not significantly associated with increased perioperative cardiac complications, return to the operating room, or mortality. Patients with MO and SO were significantly associated with increased surgical site infection (odds ratio, 1.43; 95% confidence interval, 1.02-1.98; P = .03) and increased respiratory complications (odds ratio, 1.6; 95% confidence interval, 1.11-2.31; P = .01). Multivariable analysis showed that MO and SO were not significantly associated with periprocedural access site hematoma, access site stenosis or occlusion, or mortality after PVI. CONCLUSIONS: MO and SO were significantly associated with increased incidence of wound infections and respiratory complications after LEB but were not significantly associated with increased incidence after PVI. Overall, patients with MO and SO have more comorbidities and more advanced presentation of vascular disease at the time of intervention, but MO and SO alone should not deter necessary and appropriate revascularization.

Perioperative and long-term outcomes after percutaneous thrombectomy of arteriovenous dialysis access grafts.

OBJECTIVE: Maintenance of functional arteriovenous grafts (AVGs) for dialysis is difficult secondary to low primary patency, need for reinterventions, and limited alternative dialysis access options. We assessed our experience with percutaneous thrombectomy for treatment of occluded AVGs. METHODS: We performed a retrospective analysis of all percutaneous thrombectomies for AVGs from 2015 to 2017. These were generally performed using mechanical thrombectomy and occasional chemical tissue plasminogen activator thrombolysis, over-the-wire balloon embolectomy for inflow, and adjunctive inflow and outflow interventions as necessary. Perioperative outcomes, long-term patency, reinterventions, and need for new permanent access placement were analyzed. RESULTS: There were 218 percutaneous thrombectomies performed on 86 AVGs in 77 patients. Approximately half (53.2%) of the patients were male and 68.8% were black. Mean age was 61.1 ± 13.0 years. At the time of thrombectomy, 73.8% underwent venous outflow interventions and 4.5% underwent arterial inflow interventions. Within 30 days, 24.8% of declotted grafts underwent repeated percutaneous thrombectomy, 14.3% required tunneled dialysis catheter placement, 4% developed minor access site or graft infections, and one patient underwent surgical arterial thrombectomy for arm ischemia. There were no venous thromboembolic, cardiopulmonary, or cerebrovascular complications or clinically significant pulmonary embolism. At 1 year and 3 years after percutaneous thrombectomy, freedom from repeated thrombosis was 37% and 18%, respectively, and freedom from new dialysis access placement was 66% and 51%, respectively. Overall patient survival was 82% at 3 years. CONCLUSIONS: Percutaneous thrombectomy of AVGs is safe and is associated with acceptable patency rates. This minimally invasive method extends AVG use for these high-risk patients with limited dialysis access options.

Shunt intention during carotid endarterectomy in the early symptomatic period and perioperative stroke risk.

OBJECTIVE: Whether recent stroke mandates planned shunting during carotid endarterectomy (CEA) is controversial. Our goal was to determine associations of various shunting practices with postoperative outcomes of CEAs performed after acute stroke. METHODS: The Vascular Quality Initiative database (2010-2018) was queried for CEAs performed within 14 days of an ipsilateral stroke. Surgeons who prospectively planned to shunt either shunted routinely per their usual practice or shunted selectively for preoperative indications. Surgeons who prospectively planned not to shunt either shunted selectively for intraoperative indications or did not shunt. Univariable and multivariable analyses compared shunting approaches. RESULTS: There were 5683 CEAs performed after acute ipsilateral stroke. Surgeons planned to shunt in 56.1% of cases. Patients whose surgeons planned to shunt vs planned not to shunt were more likely to have severe contralateral stenosis (8.8% vs 6.9%; P = .008), to receive general anesthesia (97.5% vs 89.1%; P < .001), and to undergo conventional CEA (94% vs 81.8%; P < .001). Unadjusted outcomes were similar between the cohorts for operative duration (124.3 ± 48.1 minutes vs 123.6 ± 47 minutes; P = .572) and 30-day stroke (3.4% vs 3%; P = .457), myocardial infarction (1.1% vs 0.8%; P = .16), and mortality (1.6% vs 1.3%; P = .28). On multivariable analysis, planning to shunt vs planning not to shunt was associated with similar risk of 30-day stroke (odds ratio [OR], 1.17; 95% confidence interval [CI], 0.82-1.67; P = .402). On subgroup analysis, in 38.4% patients, no shunt was placed, whereas the remainder received routine shunts (44.4%), preoperatively indicated shunts (11.6%), and intraoperatively indicated shunts (5.5%). Compared with no shunting, shunting by surgeons who routinely shunt was associated with a similar stroke risk (OR, 1.39; 95% CI, 0.91-2.13; P = .129), but shunting by surgeons who selectively shunt on the basis of preoperative indications (OR, 2.11; 95% CI, 1.22-3.63; P = .007) or intraoperative indications (OR, 3.34; 95% CI, 1.86-6.01; P < .001) was associated with increased stroke risk. Prior coronary revascularization independently predicted increased intraoperatively indicated shunting (OR, 1.37; 95% CI, 1.05-1.8; P = .022). CONCLUSIONS: In CEAs performed after acute ipsilateral stroke, there is no difference in postoperative stroke risk when surgeons prospectively plan to shunt or not to shunt. Shunting is often not necessary; however, when shunting is performed, routine shunters achieve better outcomes.

Association of Anesthesia Type with Outcomes after Outpatient Brachiocephalic Arteriovenous Fistula Creation.

BACKGROUND: Brachiocephalic arteriovenous fistulas (BCFs) are commonly placed in outpatient settings. The impact of general anesthesia (GA), regional anesthesia (RA), or local anesthesia (LA) on perioperative recovery and fistula maturation/patency after outpatient BCF creations is unknown. We evaluated whether outcomes of outpatient BCF creations vary based on anesthesia modality. METHODS: The Vascular Quality Initiative (2011-2018) national database was queried for outpatient BCF creations. Anesthesia modalities included GA, RA, and LA. Perioperative, 3-month, and 1-year outcomes were compared between GA versus RA/LA anesthesia types. RESULTS: Among 3,527 outpatient BCF creations, anesthesia types were GA in 1,043 (29.6%), RA in 1,150 (32.6%), and LA in 1,334 (37.8%). Patients receiving GA were more often younger, obese, Medicaid recipients, without coronary artery disease, and treated in non-office-based settings (P < 0.05 for all). GA compared with RA/LA cohorts were more often admitted postoperatively (5.3% vs. 2.4%, P < 0.001) but had similar rates of thirty-day mortality (0.9 vs. 0.6%, P = 0.39). 3-month access utilization for hemodialysis was lower in GA than in RA/LA cohorts (12.6% vs. 23.6%, P < 0.001). The Kaplan-Meier analysis showed that GA and RA/LA cohorts had similar 1-year primary access occlusion-free survival (43.6% vs. 47.1%, P = 0.24) and endovascular/open reintervention-free survival (57.2% vs. 57.6%, P = 0.98). On multivariable analysis, GA compared with RA/LA use was independently associated with increased postoperative admission (odds ratio [OR]: 1.7, 95% confidence interval [CI]: 1.08-2.67, P = 0.02) and decreased 3-month access utilization (OR: 0.39, 95% CI: 0.25-0.61, P < 0.001) but had similar 1-year access occlusion (hazard ratio [HR]: 1.09, 95% CI: 0.9-1.32, P = 0.36) and reintervention (HR: 1.02, 95% CI: 0.82-1.26, P = 0.88). On subgroup analysis of the RA/LA cohort, RA compared with LA was associated with increased 3-month access utilization (OR: 1.6, 95% CI: 1.01-2.5; P = 0.04) and 1-year access reintervention (HR: 1.46, 95% CI: 1.12-1.89), but had similar 1-year access occlusion (HR: 1.2, 95% CI: 0.95-1.51, P = 0.13). CONCLUSIONS: Compared with RA/LA use, GA use in patients undergoing outpatient BCF creations was associated with increased hospital admissions, decreased access utilization at 3 months, and similar 1-year access occlusion and reintervention. RA/LA is preferable to expedite recovery and access utilization.

c-Cbl Expression Correlates with Human Colorectal Cancer Survival and Its Wnt/ß-Catenin Suppressor Function Is Regulated by Tyr371 Phosphorylation.

The proto-oncogene ß-catenin drives colorectal cancer (CRC) tumorigenesis. Casitas B-lineage lymphoma (c-Cbl) inhibits CRC tumor growth through targeting nuclear ß-catenin by a poorly understood mechanism. In addition, the role of c-Cbl in human CRC remains largely underexplored. Using a novel quantitative histopathologic technique, we demonstrate that patients with high c-Cbl-expressing tumors had significantly better median survival (3.7 years) compared with low c-Cbl-expressing tumors (1.8 years; P = 0.0026) and were more than twice as likely to be alive at 3 years compared with low c-Cbl tumors (P = 0.0171). Our data further demonstrate that c-Cbl regulation of nuclear ß-catenin requires phosphorylation of c-Cbl Tyr371 because its mutation compromises its ability to target ß-catenin. The tyrosine 371 (Y371H) mutant interacted with but failed to ubiquitinate nuclear ß-catenin. The nuclear localization of the c-Cbl-Y371H mutant contributed to its dominant negative effect on nuclear ß-catenin. The biological importance of c-Cbl-Y371H was demonstrated in various systems, including a transgenic Wnt-8 zebrafish model. c-Cbl-Y371H mutant showed augmented Wnt/ß-catenin signaling, increased Wnt target genes, angiogenesis, and CRC tumor growth. This study demonstrates a strong link between c-Cbl and overall survival of patients with CRC and provides new insights into a possible role of Tyr371 phosphorylation in Wnt/ß-catenin regulation, which has important implications in tumor growth and angiogenesis in CRC.

Snuffbox arteriovenous fistulas have similar outcomes and patency as wrist arteriovenous fistulas.

OBJECTIVE: Radial artery-based wrist arteriovenous fistulas (AVFs) are commonly created as an initial upper extremity arteriovenous access. A more distal access site, such as the anatomic snuffbox AVF, can also be created. Although much has been written about wrist AVFs, outcomes of snuffbox AVFs are unclear. Our goal was to compare perioperative and midterm outcomes between these two types of distal access. METHODS: The Vascular Quality Initiative database was queried for all patients undergoing snuffbox AVFs and wrist AVFs from 2011 to 2017. Unmatched and matched analyses were performed for baseline characteristics and outcomes at 6 months for ischemic steal, wound infection, and arm swelling. Multivariable analysis was performed for unmatched and matched analyses for primary patency, surgical or endovascular repair, and patient survival. Kaplan-Meier matched analysis was performed for primary patency, freedom from surgical or endovascular intervention, and survival. RESULTS: We identified 4525 distal forearm fistulas: 179 (4%) snuffbox AVFs and 4346 (96%) wrist AVFs. The average age was 59 ± 14.7 years, and 72.3% of patients were male. There were no significant differences in baseline demographics or comorbidities of patients with snuffbox AVFs and wrist AVFs except that patients with snuffbox AVFs had fewer tunneled lines at access creation (70.2% vs 65.2%; P = .046) and had a lower American Society of Anesthesiologists class. There were no significant differences in unmatched outcomes at 6 months for ischemic steal (0.8% vs 1.9%; P = .336), wound infection (0% vs 0.2%; P = .649), and arm swelling (0.8% vs 1.3%; P = .592). Matched analysis showed no significant differences in baseline characteristics and outcomes at 6 months for ischemic steal (0% vs 1.8%; P = .146), wound infection (0% vs 0%), and arm swelling (0.9% vs 1.2%; P = .789). Kaplan-Meier matched analysis showed no significant differences between snuffbox AVFs and wrist AVFs at 6 months for primary patency (51% vs 48%; P = .61), freedom from endovascular intervention (84.5% vs 82.5%; P = .98), freedom from surgical intervention (90% vs 86%; P = .08), and survival (92% vs 96%; P = .1). In multivariable analysis of unmatched data, snuffbox AVFs and wrist AVFs had similar primary patency (hazard ratio [HR], 0.97; 95% confidence interval [CI], 0.75-1.26; P = .83), likelihood of surgical intervention (HR, 0.61; 95% CI, 0.35-1.05; P = .074) and endovascular intervention (HR, 0.96; 95% CI, 0.65-1.42; P = .83), and survival (HR, 1.47; 95% CI, 0.9-2.4; P = .128). CONCLUSIONS: Snuffbox AVFs have midterm results similar to those of wrist AVFs.

The effect of the duration of preoperative smoking cessation timing on outcomes after elective open abdominal aortic aneurysm repair and lower extremity bypass.

OBJECTIVE: Smoking has been associated with poor postoperative outcomes across various surgical procedures. However, the effect of quitting smoking preoperatively for elective operations is unclear. Our goal was to assess the temporal effect of smoking cessation before elective lower extremity bypass (LEB) and open abdominal aortic aneurysm (AAA) repair on perioperative outcomes. METHODS: The Vascular Quality Initiative was reviewed for all patients with a documented smoking history and who underwent an elective LEB or open AAA repair from 2010 to 2017. Patients were then categorized into three groups: long-term smoking cessation (LTSC; defined as quitting smoking ≥8 weeks before surgery), short-term smoking cessation (STSC; defined as quitting smoking < 8 weeks before surgery), and current smokers (CS). Patient and procedure details were recorded. Univariate and multivariate analysis for crude and propensity-matched data were used to compare outcomes among groups. RESULTS: We identified 15,950 patients with a documented smoking history who underwent an elective LEB (43.3% LTSC, 2.2% STSC, 54.5% CS) and 5215 patients who underwent an elective open AAA repair (42.9% LTSC, 2.4% STSC, 54.7% CS). LTSC patients compared with STSC and CS, respectively, were more often obese, diabetic, on aspirin, on a statin, had coronary artery disease, and had congestive heart failure, but were less likely to have chronic obstructive pulmonary disease (all P < .05). Perioperative outcomes demonstrated significant differences comparing LTSC with STSC and CS for myocardial infarction (3.4% vs 1.4% vs 1.4%), dysrhythmia (4.2% vs 2.5% vs 2.7%), 30-day mortality (1.6% vs .3% vs .9%), in-hospital mortality (1.1% vs 0% vs 0.5%; all P < .001) and congestive heart failure (1.8% vs .8% vs 1.5%; P = .003). There was no difference in outcomes after analysis of propensity-matched data for LTSC or STSC on any postoperative outcomes for LEB. For open AAA repair, LTSC compared with CS patients, respectively, were older, more often male, obese, on a statin, diabetic, and less frequently had chronic obstructive pulmonary disease (P < .05 for all). Perioperative outcomes demonstrated differences in pulmonary complications when comparing LTSC with STSC and CS (9.5% vs 8.0% vs 12.5%; P = .002). Multivariate analysis demonstrated that LTSC patients compared with CS were less likely to experience pulmonary complications (odds ratio, 0.65; 95% confidence interval, 0.53-0.79; P < .001). Propensity-matched multivariate analysis confirmed that LTSC remained significantly less likely to encounter pulmonary complications (odds ratio, 0.49; 95% confidence interval, 0.33-0.74; P = .001). CONCLUSIONS: In our propensity-matched, risk-adjusted cohort, LTSC and STSC were not associated with perioperative outcomes after elective LEB. LTSC was associated with a significantly decreased odds of pulmonary complications after elective open AAA repair. STSC was not associated with perioperative outcomes after elective open AAA repair. If time permits, a longer period of smoking cessation should be attempted before elective open AAA repair.

Patients with lower extremity dialysis access have poor primary patency and survival.

OBJECTIVE: Lower extremity arteriovenous (AV) access is an alternative when upper extremity access options have been exhausted. Our goal was to assess short- and medium-term outcomes of lower extremity hemodialysis access. METHODS: The Vascular Quality Initiative was reviewed for all lower extremity AV hemodialysis cases. Patient and case details were recorded. Multivariable analysis was used to analyze outcomes. RESULTS: We identified 463 lower extremity AV access cases in the VQI registry. There were 56 AVF (12.1%) and 407 AVG (87.9%). The mean age was 56 ± 15 years, 46.9% were male, and 40.7% were Caucasian. The majority (90%) had a previous upper extremity AV access and 25.4% had a prior lower extremity access. More than one-half (57.9%) had a tunneled line at the time of the procedure. Patients undergoing an AVF vs AVG creation were younger, more often ambulatory, and less often with peripheral arterial disease. For AVF, the superficial femoral artery was more often used for access inflow (76.8% vs 49.4%; P < .001), compared with AVG, and there was no difference in using femoral vein as the main outflow (78.6% vs 82.6%; P = .466). For AVF, compared with AVG, there was no difference in wound infection (12.5% vs 9.6%; P = .571), ischemic steal (5% vs 2.2%; P = .273), or leg swelling (2.5% vs 3.3%; P = .99) at 6 months. Kaplan-Meier analysis of the overall cohort showed that freedom from loss of primary patency at 6 months was 52.9%, freedom from any reintervention at 6 months was 75.3%, and the 1-year survival was 81.9%. Survival at 5 years was 65.5%. Multivariable analysis showed no significant association of access type (AVF vs AVG) with primary patency loss or death (hazard ratio [HR], 0.74; 95% confidence interval [CI], 0.36-1.5; P = .4), any reintervention or death (HR, 1.65; 95% CI, 0.82-3.33; P = .163), or mortality (HR, 1.94; 95% CI, 0.71-5.33; P = .197). Factors independently associated with primary patency loss or death included peripheral arterial disease (HR, 1.6; 95% CI, 1.06-2.42; P = .03) and obesity (HR, 1.5; 95% CI, 1.1-2.05; P = .01). Any reintervention or death was associated with obesity (HR, 1.67; 95% CI, 1.09-2.56; P = .015). Mortality was associated with congestive heart failure (HR, 1.82; 95% CI, 1.13-2.94; P = .015) and white race (HR, 1.71; 95% CI, 1.08-2.73; P = .023). CONCLUSIONS: In our contemporary multicenter analysis, patients undergoing lower extremity AV access creation have low primary access patency and almost 20% mortality at 1 year. These results should be considered when suggesting a lower extremity dialysis access, as well as other dialysis alternatives when available.