Platelet function testing and clinical outcomes in peripheral arterial disease: Systematic review and narrative synthesis.

OBJECTIVE: This systematic review aims to comprehensively assess the contemporary literature on platelet function testing (PFT) in individuals undergoing revascularization therapy for peripheral arterial disease (PAD). The goal is to identify whether PFT can aid in detecting antiplatelet resistance, predicting post-procedural thrombotic complications, and informing tailored treatment strategies. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a literature review was conducted using PubMed databases. Search terms included relevant medical subject headings (MeSH) terms. Eligible articles published in English between 1990 and 2023 were analyzed. Studies that examined PFT outcomes in patients with PAD after lower extremity revascularization were included. RESULTS: Ten studies met the inclusion criteria. Various PFT methods were used, including thromboelastography with platelet mapping, multiplate analyzer, Cytochrome P450 2C19 testing, VerifyNow, corrected whole blood aggregometry, platelet function analyzer-100, and light transmission aggregometry. PFT identified individuals who were resistant or non-sensitive to antiplatelet therapy, with such patients facing increased risks of graft/stent thrombosis, amputation, and reintervention. However, substantial heterogeneity in surgical procedures, drug regimens, and testing methods was observed among the studies. CONCLUSIONS: PFTs can play a crucial role in detecting resistance and non-sensitivity to antiplatelet drugs in patients with PAD post-revascularization. However, heterogeneity of data and methods underlines the need for standardized protocols and consensus-building among PFTs. Enhancing clinical utility and reliability could help optimize antiplatelet thromboprophylaxis, minimize thrombotic complications, and improve treatment strategies in vascular surgery. Further research is necessary to solidify the role of PFTs in guiding antiplatelet therapy post-revascularization in patients with PAD.

Preoperative Anemia is Associated with Poorer Postoperative Outcomes in Patients Undergoing Infrainguinal Bypass Surgery.

BACKGROUND: Preoperative anemia is an important, modifiable risk factor among surgical patients. However, data are scarce on the impact of preoperative anemia on postoperative outcomes after infrainguinal bypass. METHODS: In this multi-institutional analysis, data were retrospectively collected on all infrainguinal bypass procedures performed between 2010 and 2020. Patients were grouped by preoperative hemoglobin as per the National Cancer Institute anemia scale (mild, 10 g/dL-lower limit of normal; moderate, 8.0-9.9 g/dL; severe, 6.5-7.9 g/dL). Multivariable comparisons were performed using logistic regression analysis. RESULTS: A total of 492 patients underwent bypass for peripheral artery disease over the 10-year study period. Median preoperative hemoglobin was 11.0 g/dL (interquartile range 9.5-12.7) and median follow-up was 1.7 years. Preoperative anemia was prevalent among bypass patients (mild 52.4% [n = 258], moderate 26.4% [n = 130], and severe 5.1% [n = 25]). Women were more likely to have moderate (49.2% [women] vs. 50.8% [men]) or severe anemia (52.0% [women] vs. 48.0% [men]) compared with normal hemoglobin (17.7% [women] vs. 82.3% [men]) (P < 0.001). Patients with preoperative anemia were more likely to present with tissue loss (22.8% [normal] vs. 47.7% [moderate] vs. 52.0% [severe], P = 0.01). Bypass target and conduit types were similar between groups. Anemic patients had longer median hospital length of stay compared with nonanemic patients (4 days [normal] vs. 5 days [mild] vs. 6 days [moderate] vs. 7 days [severe], P < 0.001). Postoperative mortality at 30 days was similar across anemia groups (2.5% [normal] vs. 4.6% [moderate] vs. 8.0% [severe], P = 0.23). On multivariable analysis, however, postoperative mortality was independently associated with severe anemia (odds ratio 7.5 [1.2-48.8], P = 0.04) and male gender (odds ratio 7.5 [1.2-26.4], P = 0.03). CONCLUSIONS: Preoperative anemia is common among patients undergoing infrainguinal bypass surgery and is an independent risk factor for postoperative mortality. Future investigation is needed to determine whether correction of anemia improves postoperative outcomes in these high-risk patients.

Outcomes of Femoropopliteal Bypass for Lifestyle-Limiting Claudication in the Endovascular Era.

INTRODUCTION: Outcomes after femoropopliteal bypass for intermittent claudication (IC) remain unclear in the endovascular era. METHODS: A multi-institutional database was retrospectively queried for all femoropopliteal bypass procedures performed between 1995 and 2020. Demographics, operative details, and outcomes were documented. A statistical analysis included Kaplan-Meier curves and Cox proportional hazards ratios (HR). RESULTS: A total of 282 patients underwent femoropopliteal bypass surgery for IC. Median age was 68 y (interquartile range, 61-73 y). Bypass conduits included great saphenous vein (GSV) (48.2%), prosthetic grafts (48.9%), and non-GSV autogenous grafts (2.8%). Distal bypass target was above-knee in 62.1% and below-knee in 37.9% of patients. The most common postoperative complications were wound infections (14.2%) followed by unplanned 30-d hospital readmissions (12.4%). Mortality rates were low at 0.4% (30 d) and 3.2% (1 y). Five-year primary patency rates trended highest for claudicants undergoing above-knee bypass with GSV conduit (log-rank P = 0.065). Five-year amputation-free survival rates were highest using GSV conduit regardless of distal bypass target (log-rank P = 0.017). On a multivariable analysis, age (HR 1.02 [1.00-1.04], P = 0.023) and active smoking (HR 1.48 [1.06-2.06], P = 0.021) were identified as risk factors for diminished primary graft patency. Risk factors for amputation-free survival included age (HR 1.03 [1.01-1.05], P < 0.001) and GSV conduit type (HR 0.65 [0.46-0.90], P = 0.011). CONCLUSIONS: Femoropopliteal bypass among claudicants is associated with high rates of wound infection and hospital readmission. Active smoking portends worse outcomes in this population. These data may inform clinical decision-making regarding surgical intervention for claudication in the endovascular era.

Impact of anticoagulation/antiplatelet therapy on femoropopliteal bypass graft outcomes.

BACKGROUND: Anticoagulant and antiplatelet (AC/AP) medications have been reported to improve bypass graft patency, however, the optimal AC/AP strategy remains unclear in the heterogenous peripheral artery disease population. METHODS: A multi-institutional retrospective review utilizing the Research Patient Data Registry database from 1995 to 2020 was performed for all patients who underwent femoropopliteal bypass procedures. Electronic medical records were used to obtain demographic information, comorbidities, smoking status, operative details (bypass target), postoperative AC/AP medications, postoperative complications, and long-term outcomes and were reviewed for the cohort. Cox proportional hazards model was used to determine independent risk factors for major adverse limb events (MALE) after bypass. MALE was defined as reintervention for patency or major amputation of index limb (above- or below-knee amputation). RESULTS: A total of 1421 patients underwent femoropopliteal bypass between 1995 and 2020 throughout five institutions included in this study. Complete data were available for 1292 of the 1421 patients (90.9%). The indications for bypass included intermittent claudication (21.4%), rest pain (30.3%), tissue loss (33.5%), and nonatherosclerotic disease (14.8%). Distal bypass targets comprised above-knee (38.6%) and below-knee (61.4%) popliteal arteries. Patients were divided into six groups based on postoperative AC/AP use including none (n = 57 [4.4%]), monoantiplatelet therapy (n = 587 [45.4%]), dual AP therapy (n = 214 [16.6%]), AC alone (n = 73 [5.7%]), AC + monoantiplatelet therapy (n = 319 [24.7%]), and AC + dual AP therapy (n = 42 [3.3%]). Postoperative bleeding complications were low for both hematoma (3.7%) and pseudoaneurysm (0.7%). There was no difference in bleeding complications across AC/AP groups (hematoma, P = .61; pseudoaneurysm, P = .31). After adjusting for patient factors, below-knee bypass target (hazard ratio [HR], 1.25; 95% confidence interval [CI], 1.04-1.52; P = .019) and bypass for tissue loss (HR, 1.40; 95% CI, 1.04-1.88; P = .028) were independent predictors for MALE. Great saphenous vein conduit trended toward protection for MALE, compared with prosthetic grafts (HR, 0.84; 95% CI, 0.70-1.01; P = .06). No AC/AP regimen was associated with of MALE, even stratifying by above-knee and below-knee bypass cohorts. The median follow-up period was 2 years. CONCLUSIONS: Among patients undergoing femoropopliteal bypass grafting, no combination of AC or AP medications was associated with improved graft patency; however, a below-knee target and tissue loss were associated with adverse limb events. AC and AP regimen may be individualized after bypass with regard to other concomitant medical comorbidities.

Risk factors and consequences of graft infection after femoropopliteal bypass: A 25-year experience.

OBJECTIVE: In this multi-institutional series, we aimed to determine the incidence, risk factors, and long-term outcomes of graft infection in patients post-femoropopliteal bypass. METHODS: A multi-institutional database was retrospectively queried for all femoropopliteal bypass procedures from 1995 through 2020. Cumulative incidence function estimated the long-term rate of bypass graft infection (BGI), and the Fine-Gray model was used to determine independent risk factors for BGI to account for death as a competing risk. RESULTS: Over the 25-year period, 1315 femoral popliteal bypasses were identified with a median follow-up of 2.89 years (interquartile range, 0.75-6.55 years). BGI was diagnosed in 34 patients (2.6%). BGI occurred between 9 days and 11.2 years postoperatively, with a median of 109 days. Estimated 1- and 5-year incidence of BGI was 2.1% (95% confidence interval [CI], 1.4%-3.1%) and 2.8% (95% CI, 1.9%-3.9%), respectively. Medical comorbidities, indications for bypass, and popliteal bypass targets (above- vs below-knee) were similar between patients with BGI and all patients (P = not significant for each). Patients with BGI were more frequently complicated by postoperative hematoma (14.7% vs 3.7%), superficial wound infection (38.2% vs 19.2%), lymphocele/lymphorrhea (8.8% vs 2.1%), and 30-day readmission rates (47.1% vs 21.3%) (P < .05 for each). Most commonly isolated pathogens were Staphylococcus aureus (n = 19; 55.9%) and polymicrobial cultures (n = 5; 14.7%). Reoperation for BGI involved incision and drainage (n = 7; 20.6%), graft excision without reconstruction (n = 12; 35.3%), graft excision with in-line reconstruction (n = 11; 32.4%), and graft excision with extra-anatomic reconstruction (n = 2; 5.9%). Nine patients with BGI (26.5%) ultimately required major amputation. Prosthetic bypass (subdistribution hazard ratio [SHR], 3.73; 95% CI, 1.64-8.51; P = .002), postoperative hematoma (SHR, 3.44; 95% CI, 1.23-9.61; P = .018), and 30-day readmission (SHR, 2.75; 95% CI, 1.27-5.44; P = .010) were independently associated with BGI. One-year amputation-free survival was 50% (95% CI, 31.9%-65.7%) after BGI. CONCLUSIONS: BGI is a rare complication of femoral-popliteal bypass with significant morbidity. Graft infection is associated with the use of prosthetic grafts, postoperative hematoma, and unplanned hospital readmission. Mitigation of these risk factors may decrease the risk of this dreaded complication.

The Weekend Effect in Carotid Endarterectomy for Symptomatic Carotid Stenosis.

BackgroundRecent studies report a limited window in which carotid endarterectomy (CEA) provides the greatest benefit for symptomatic carotid stenosis. Given the time-sensitive nature of CEA for symptomatic stenosis, it is important to understand whether patient outcomes are adversely affected by undergoing CEA over the weekend. Currently, it is unclear whether CEA is impacted by the "weekend effect" phenomenon. Methods A multi-institutional database was queried for all patients undergoing CEA for symptomatic carotid artery stenosis from 2015 to 2020 via ICD-9 codes. A total of 288 patients were identified during the study period. Univariate and multivariate analysis were used to compare outcomes based on weekend vs weekday surgery. Results A total of 261 patients (90.6%) underwent weekday CEA, as compared to 27 (9.4%) on the weekend. There were no differences in age, race, gender, or medical comorbidities between groups. Primary surgeon specialty was predominantly vascular surgery (77.0% weekday and 74.1% weekend) followed by neurosurgery (19.9% weekday and 25.9% weekend). Operative time was similar between groups (3.1 (weekday) vs 2.9 hr (weekend), P = .33) as well as estimated blood loss (100 vs 100 mL, P = .54). Hospital length of stay did not differ between groups (P = .69). Combined stroke and 30-day mortality rate was 2.0% on weekdays, compared to 3.7% on weekends (P = .75). On multivariate analysis, weekend surgery was not predictive of postoperative stroke or 30-day mortality (odds ratio .11 [95% CI: -1.57 to 1.85], P = .90). Conclusion In our multi-institutional experience, we did not identify a "weekend effect" in patients undergoing CEA for symptomatic carotid artery stenosis. Surgical revascularization should not be withheld on account of a weekend procedure in similar academic medical centers.

A systematic review of thromboelastography utilization in vascular and endovascular surgery.

OBJECTIVE: Thromboelastography (TEG) is diagnostic modality that analyzes real-time blood coagulation parameters. Clinically, TEG primarily allows for directed blood component resuscitation among patients with acute blood loss and coagulopathy. The utilization of TEG has been widely adopted in among other surgical specialties; however, its use in vascular surgery is less prominent. We aimed to provide an up-to-date review of TEG utilization in vascular and endovascular surgery. METHODS: Using Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, a literature review with the Medical Subject Headings (MeSH) terms "TEG and arterial events", "TEG and vascular surgery", "TEG and vascular", "TEG and endovascular surgery", "TEG and endovascular", "TEG and peripheral artery disease", "TEG and prediction of arterial events", "TEG and prediction of complications ", "TEG and prediction of thrombosis", "TEG and prediction of amputation", and "TEG and amputation" was performed in Cochrane and PubMed databases to identify all peer-reviewed studies of TEG utilization in vascular surgery, written between 2000 and 2021 in the English language. The free-text and MeSH subheadings search terms included diagnosis, complications, physiopathology, surgery, mortality, and therapy to further restrict the articles. Studies were excluded if they were not in humans or pertaining to vascular or endovascular surgery. Additionally, case reports and studies with limited information regarding TEG utilization were excluded. Each study was independently reviewed by two researchers to assess for eligibility. RESULTS: Of the 262 studies identified through the MeSH strategy, 15 studies met inclusion criteria and were reviewed and summarized. Literature on TEG utilization in vascular surgery spanned cerebrovascular disease (n = 3), peripheral arterial disease (n = 3), arteriovenous malformations (n = 1), venous thromboembolic events (n = 7), and perioperative bleeding and transfusion (n = 1). In cerebrovascular disease, TEG may predict the presence and stability of carotid plaques, analyze platelet function before carotid stenting, and compare efficacy of antiplatelet therapy after stent deployment. In peripheral arterial disease, TEG has been used to predict disease severity and analyze the impact of contrast on coagulation parameters. In venous disease, TEG may predict hypercoagulability and thromboembolic events among various patient populations. Finally, TEG can be utilized in the postoperative setting to predict hemorrhage and transfusion requirements. CONCLUSIONS: This systematic review provides an up-to-date summarization of TEG utilization in multiple facets of vascular and endovascular surgery.

The current status of the diversity pipeline in surgical training.

OBJECTIVE: Recent initiatives have emphasized the importance of diversity, equity, and inclusion in academic surgery. Racial/ethnic disparities remain prevalent throughout surgical training, and the "diversity pipeline" in resident recruitment and retention remains poorly defined. METHODS: Data was retrospectively collected using two separate datasets. The Association of American Medical Colleges database was used to obtain demographic data on US medical school graduates. The US Graduate Medical Education annual report was used to obtain demographic data on surgical residents. Wilcoxon signed-rank test was used to compare racial/ethnic distribution within surgical residency programs with graduating medical students. Linear regression analysis was performed to analyze population trends over time. RESULTS: The study population included 184,690 surgical residents from 2011 to 2020. Nine resident cohorts were created according to surgical specialty - general surgery, neurosurgery, ophthalmology, orthopedic surgery, otolaryngology, plastic surgery, cardiothoracic surgery, urology, and vascular surgery. Among surgical programs, White residents were overrepresented in 8 of 9 specialties compared to the concurrent graduating medical student class for all years (p < 0.01 each, no difference in ophthalmology). Black residents were underrepresented in 8 of 9 specialties (p < 0.01 each, no difference in general surgery). Asian representation was mixed among specialties (4 overrepresented, 1 equal, 4 underrepresented), as was Hispanic representation (5 overrepresented, 4 equal) (p < 0.01 each). CONCLUSIONS: These data suggest that racial/ethnic disparities are inherent to the process of recruitment and retention of surgical residents. Efforts to improve the "diversity pipeline" should focus on mentorship and development of minority medical students and creating an equitable learning environment.