Impact of COVID-19 on patients undergoing scheduled procedures for chronic venous disease.

OBJECTIVE: The COVID-19 pandemic has drastically altered the medical landscape. Various strategies have been employed to preserve hospital beds, personal protective equipment, and other resources to accommodate the surges of COVID-19 positive patients, hospital overcapacities, and staffing shortages. This has had a dramatic effect on vascular surgical practice. The objective of this study is to analyze the impact of the COVID-19 pandemic on surgical delays and adverse outcomes for patients with chronic venous disease scheduled to undergo elective operations. METHODS: The Vascular Surgery COVID-19 Collaborative (VASCC) was founded in March 2020 to evaluate the outcomes of patients with vascular disease whose operations were delayed. Modules were developed by vascular surgeon working groups and tested before implementation. A data analysis of outcomes of patients with chronic venous disease whose surgeries were postponed during the COVID-19 pandemic from March 2020 through February 2021 was performed for this study. RESULTS: A total of 150 patients from 12 institutions in the United States were included in the study. Indications for venous intervention were: 85.3% varicose veins, 10.7% varicose veins with venous ulceration, and 4.0% lipodermatosclerosis. One hundred two surgeries had successfully been completed at the time of data entry. The average length of the delay was 91 days, with a median of 78 days. Delays for venous ulceration procedures ranged from 38 to 208 days. No patients required an emergent intervention due to their venous disease, and no patients experienced major adverse events following their delayed surgeries. CONCLUSIONS: Interventions may be safely delayed for patients with venous disease requiring elective surgical intervention during the COVID-19 pandemic. This finding supports the American College of Surgeons' recommendations for the management of elective vascular surgical procedures. Office-based labs may be safe locations for continued treatment when resources are limited. Although the interventions can be safely postponed, the negative impact on quality of life warrants further investigation.

Predictors of poor outcomes after lower extremity revascularization for acute limb ischemia.

OBJECTIVES: Acute lower extremity ischemia is one of the most common emergencies in vascular surgery and is a cause of considerable morbidity and mortality. The goal of this study was to evaluate outcomes of revascularization for acute lower extremity ischemia and to determine factors associated with perioperative morbidity and mortality. METHODS: A total of 354 patients underwent urgent revascularization for acute lower extremity ischemia at an academic medical center between 2014 and 2019. A retrospective review of patients' demographics, comorbidities, etiology and severity of limb ischemia, and procedural characteristics was recorded. Outcomes, including postoperative complications, perioperative limb loss, and mortality, were analyzed. RESULTS: The mean patient age was 69 ± 17 years, and 52% were females. 50% of patients presented with Rutherford Class IIb ischemia. Arterial embolization was the most common cause of limb ischemia, seen in 33% of cases. Open surgical revascularization was performed in 241 (68%) patients, while endovascular and hybrid approaches were utilized in 53 (15%) and 60 (17%) cases, respectively. Postoperative adverse events occurred in 44% of patients, including wound complications (11%), cardiac (5%) and pulmonary (16%) complications, strokes (4%), UTIs (10%), renal failure (14%), bleeding (5%), and compartment syndrome (3%). The rate of unplanned return to the operating room was 21%. Major adverse cardiovascular events were seen in 103 (29%) patients and major adverse limb events were seen in 57 (16%) patients. The median length of stay was 10 days (IQR = 4); 49% patients were discharged to skilled nursing facility and 19% were readmitted within 30 days.The rate of amputation during index admission was 10%, and perioperative mortality was 20%. Gender, tibial runoff, and etiology of limb ischemia were independent predictors of limb loss. Women had lower risk of limb loss than men (OR, 0.11; 95% CI, 0.023, 0.38). Poor tibial runoff (one-vessel or absence of flow below the knee) was a significant predictor of limb loss as compared to three-vessel runoff (OR, 14.92; 95% CI, 1.92, 115.88). Aneurysmal disease (OR, 38.35; 95% CI, 3.54, 42.45) and traumatic injuries (OR, 108.08; 95% CI, 8.21, 159.06) were the strongest predictors of amputation as compared to other etiologies of limb ischemia. Multivariate model identified ESRD (OR, 9.2; 95% CI, 1.8-46.3), degree of ischemia (class IIb or higher vs class IIa; OR, 3.5; 95% CI, 1.2-10.6), and age (OR, 1.5; 95% CI 1.1-2.0 for every 10 years) as independent predictors of perioperative mortality. CONCLUSIONS: Urgent revascularization for management of acute limb ischemia is associated with high morbidity and mortality. Elderly patients with ESRD presenting with severely threatened limbs have especially high risk of perioperative mortality and may not be ideal candidates for limb salvage.

The Role of Duplex Ultrasound in Assessing AVF Maturation.

BACKGROUND: Arteriovenous fistulas (AVFs) are favored for hemodialysis (HD) access. However, in many instances, AVFs fail to mature. We examined the utility of postoperative color duplex ultrasound (CDU) in assessing AVF maturation and determining the need for balloon-assisted maturation (BAM). METHODS: A total of 633 patients underwent AVF creation at a single institution from 2015 to 2018. A total of 339 patients (54%) underwent CDU at a median of 8 weeks postoperatively. We collected the following parameters: vein diameter, volume flow (VF), peak systolic velocities in arterial inflow and venous outflow, and presence of stealing branches. A peak systolic velocity ratio (SVR) of ≥2 correlated with ≥50% stenosis in venous outflow, and SVR ≥3 correlated with ≥50% stenosis at the anastomosis. AVFs were considered mature when they were successfully cannulated on dialysis. A generalized linear mixed model (GLMM) was created to compare duplex criteria associated with successful use of AVF (maturation) to those AVFs that required further intervention or failed to mature. Fistulography images, the current gold standard, were compared with findings from CDU studies to determine validity of the duplex ultrasound. RESULTS: Of the 339 AVFs with postoperative CDU, 31.3% matured without interventions, 38.3% required BAM, 9.7% thrombosed, and the remaining patients were not yet on HD. Based on GLMM analysis, the probability of AVF maturation increases if CDU demonstrated one of the following: the vein diameter is ≥ 6 (odds ratio [OR] = 38.7), no evidence of stenosis in the venous outflow tract (OR = 35.6), no stealing branches (OR = 21.6) and VF ≥ 675 (OR = 5.0). Fistulography was performed in 195 patents. Sensitivity and specificity for each are as follows: vein diameter (84.3%, 28.6%), stenosis (59.3%, 78.8%), and stealing branches (20.7%, 92.7%). CONCLUSIONS: Postoperative CDU should be considered routine to correct anatomical findings that might limit AVF maturation and identify the need for further interventions.

Maturation Rates of Arteriovenous Fistulas Using Small Veins in the Era of Endovascular Interventions.

BACKGROUND: Traditional practice suggests the abandonment of veins smaller than 3 mm in diameter for arteriovenous fistula (AVF) creation because of a low rate of maturation. This study aims to show that with balloon-assisted maturation (BAM), undersized veins can be used to create functional AVFs with a high rate of success. METHODS: All patients who underwent AVF creation between 2014 and 2018 at a tertiary academic medical center were retrospectively reviewed. The patients without preoperative vein mapping, those who failed to follow-up, and the patients who were not on dialysis were excluded. A fistula was considered to be mature if it was successfully cannulated for dialysis. A total of 596 patients were identified for analysis. The cohort was divided into the small-vein group (SVG, <2.5 mm) and large-vein group (LVG, ≥2.5 mm) based on preoperative vein size. Categorical variables were analyzed with the chi-squared test for their association with maturation status. Continuous variables were analyzed with the Wilcoxon rank sum test. A P-value less than 0.05 was considered significant. RESULTS: In the study cohort, 61.9% of the patients were male, with an average age of 62.8 ± 13.7 years, and an average preoperative vein size of 2.9 ± 1.1 mm. With similar demographic distribution, the participants in the SVG (n = 216) had significantly smaller preoperative vein size of 1.9 ± 0.4 mm than the patients in the LVG (n = 380), 3.5 ± 0.8 mm (P = 0.001). There were significantly more radio-cephalic AVFs created in the SVG (77.8% versus 48.7%, P < 0.0001). The overall maturation rate was 83.1% (n = 495), 219 fistulas (36.7%) matured primarily and 276 (46.3%) required interventions. Ninety-one percent of the patients required only 1 or 2 BAMs to achieve maturation. The SVG achieved a maturation rate of 75.9% as compared with 87.1% in the LVG (P = 0.002). A significantly higher number of patients in the SVG required BAM for maturation as compared with the LVG (67.7% versus 49.9%, P = 0.0002); however, there was no difference in the average number of BAMs required for fistula maturation between the groups (1.5 ± 0.8 for the SVG vs. 1.4 ± 0.7 for the LVG). In multivariable logistic regression analysis, vein size ≥2.5 mm (odds ratio (OR) = 2.11, confidence interval (CI): 1.36-3.27, P = 0.0009) and male sex (OR = 2.30, CI: 1.49-3.57, P = 0.0002) were independent predictors of maturation. CONCLUSIONS: Small veins can be used for AVF creation with lower but still favorable maturation rates using BAM interventions, especially in male patients. This practice can increase the creation of autogenous dialysis access and potentially reduce complications related to prosthetic dialysis access.

Sex disparities in hemodialysis access outcomes: A systematic review.

The goal of this systematic review was to collate and summarize the current literature on hemodialysis access outcomes in females, identify differences between females and men, and provide a foundation for future research. A systematic review of the English-language literature was conducted by searching PubMed and Google Scholar for the following terms: "sex," "hemodialysis access," "arteriovenous fistula," "arteriovenous graft," and "dialysis catheter." Reference lists from the resulting articles were also evaluated to ensure that any and all relevant primary sources were identified. Studies were then screened by two independent reviewers for inclusion. Of 967 total studies, 53 ultimately met inclusion criteria. Females have lower maturation rates; have decreased rates of primary, primary-assisted, and secondary patency; require more procedures per capita to achieve maturation and to maintain fistula patency; are more likely to receive dialysis via an arteriovenous graft or central venous catheter; and require a longer time and potentially more assistive invasive interventions to achieve a mature fistula. Our findings emphasize the urgent need for further research to evaluate and address the causes of these disparities. Discussion with patients undergoing hemodialysis should include these findings to improve patient education, expectations, satisfaction, and outcomes.

Modified Banding of Arteriovenous Fistulas for the Treatment of Vascular Access Induced Digital Ischaemia.

OBJECTIVE: Vascular access induced digital ischaemia is an uncommon complication of haemodialysis access procedures and is difficult to manage. Several techniques have been described to treat this phenomenon, with variable long term success. Although all of these procedures have been shown to work, they have a significant failure rate, such as persistent high vascular access flow or loss of access. One of the major technical limitations of these techniques is the lack of quantitative data gathered during the procedure to ensure treatment success. In this study, the aim was to describe a novel technique that can improve the success of banding in preserving access and eliminating digital ischaemia. TECHNIQUE: A modified method for arteriovenous fistula banding that incorporates measurements of distal arterial pressure to improve the success of the procedure is described. RESULTS: Sixteen patients with vascular access induced digital ischaemia and high-flow vascular access were treated using the technique. All procedures were technically successful. At 30 days, complete symptomatic relief (clinical success) was seen in 81% (n = 13) of patients. There was no access thrombosis or infection in any of the patients at the 30 day follow up. Six month follow up data were available in seven patients. There was no loss of access patency or recurrence of symptoms observed at six months. CONCLUSION: This novel technique is simple and effective and can be used safely as first line therapy for the management of vascular access induced digital ischaemia.

Inhibition of Ca2+-independent phospholipase A2 decreases prostate cancer cell growth by p53-dependent and independent mechanisms.

The mechanisms by which Ca(2+)-independent phospholipase A(2) (iPLA(2)) mediates cell growth in p53-positive LNCaP and p53-negative PC-3 prostate cancer cell lines were studied. Exposure of cells to the iPLA(2) selective inhibitor bromoenol lactone (BEL; 0-20 microM) induced concentration- and time-dependent decreases in cell growth based on 3-(4, dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide staining and cell number. Decreased cell growth was not caused by cell death as BEL exposure did not alter nuclear morphology or increase annexin V (apoptotic cell marker) or propidium iodide (necrotic cell marker) staining after 48 h. Decreased growth correlated to a G(1)/G(0) arrest in LNCaP cells and aG(2)/M arrest in PC-3 cells. In LNCaP cells, G(1) arrest was preceded by time- (0-48 h) and concentration-dependent (0-10 microM) increases in the expression of the tumor suppressor protein p53 and the cyclin-dependent kinase inhibitor p21. Increases in p53 expression preceded increases in p21 expression by 8 h. In LNCaP cells, BEL treatment decreased the expression of the p53 antagonist Mdm2, while increasing Akt phosphorylation. BEL treatment also increased Akt phosphorylation in PC-3 cells, but Mdm2 was not detected. The ability of BEL to increase Akt phosphorylation was inhibited by the phosphoinositide 3-kinase inhibitor LY294002 [2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one]. BEL treatment also decreased agonist-induced activation of the epidermal growth factor receptor. These data suggest that inhibition of iPLA(2) decreases prostate cancer cell growth by p53-dependent and independent mechanisms. Furthermore, alterations in Mdm2 and epidermal growth factor receptor activation following BEL exposure suggest novel roles for iPLA(2) in prostate cancer cell signaling.

Laparoscopic cholecystectomy for biliary dyskinesia in children: frequency increasing.

PURPOSE: The treatment of children with biliary dyskinesia (BD) is controversial. As we recently observed an increasing frequency of referrals for BD in our institution the aim of the study was to re-evaluate the long-term outcome in children with BD. METHODS: Children with laparoscopic cholecystectomy (LC) for suspected BD between 8/2006 and 5/2011 were included. A pathologic ejection fraction (EF) was defined as <35%. The long-term effect of cholecystectomy was assessed via a Likert scale symptom questionnaire. RESULTS: 82 children (median age 13.5 years, mean BMI 25.8) were included. CCK-HIDA scan was pathologic in 74 children (90.2%). Mean EF was 16.4%. Histology revealed chronic cholecystitis in 48 (58.5%) children and was normal in 30 children (36.5%). The frequency of LC for suspected BD increased by a factor of 4.3 in the last 10 years. Long term follow-up showed that only 23/52 children (44.2%) were symptom-free after LC. Patients with chronic inflammation were more likely to have persistent symptoms (p=0.017). An EF<15% was associated with a resolution of symptoms (p=0.031). CONCLUSION: The frequency of LC for suspected BD in our institution has increased significantly during recent years. The long-term efficacy in our cohort was only 44.2%. We believe that laparoscopic cholecystectomy is likely helpful in patients with an EF<15%. However, in children with an EF of 15%-35%, based upon our data, we would highly recommend an appropriately thorough pre-op testing to exclude other gastrointestinal disorders prior to consideration of operative management.