Predicting wound complications following lower extremity revascularization.

OBJECTIVE: The aim of this study was to create a simple risk score to identify factors associated with wound complications after infrainguinal revascularization. METHODS: The Veterans Affairs Surgical Quality Improvement Program national data set was queried from 2005 to 2021 to identify 22,114 patients undergoing elective open revascularization for peripheral arterial disease (claudication, rest pain, tissue loss) or peripheral aneurysm. Emergency and trauma cases were excluded. The data set was divided into a two-thirds derivation set and one-third validation set to create a risk prediction model. The primary end point was wound complication (wound dehiscence, superficial/deep wound surgical site infection). Eight independent risk factors for wound complications resulted from the model and were assigned whole number integer risk scores. Summary risk scores were collapsed into categories and defined as low (0-3 points), moderate (4-7 points), high (8-11 points), and very high (>12 points). RESULTS: The wound complication rate in the derivation data set was 9.7% (n = 1428). Predictors of wound complication included age ≤73 (odds ratio [OR], 1.25; 95% confidence interval [CI], 1.08-1.46), body mass index ≥35 kg/m2 (OR, 1.99; 95% CI, 1.68-2.36), non-Hispanic White (vs others: OR, 1.48; 95% CI, 1.30-1.69), diabetes (OR, 1.23; 95% CI, 1.10-1.37), white blood cell count >9900/mm3 (OR, 1.18; 95% CI, 1.03-1.35), absence of coronary artery disease (OR, 1.27; 95% CI, 1.03-1.35), operative time >6 hours (OR, 1.20; 95% CI, 1.05-1.37), and undergoing a femoral endarterectomy in conjunction with bypass (OR, 1.34; 95% CI, 1.14-1.57). In both the derivation and validation sets, wound complications correlated with risk category. Among the defined categories in the derivation set, wound complication rates were 4.5% for low-risk patients, 8.5% for moderate-risk patients, 13.8% for high-risk patients, and 23.8% for very high-risk patients, with similar results for the internal validation data set. Operative indication did not independently associate with wound complications. Patients with wound complications had higher rates of reoperation and graft failure. CONCLUSIONS: This risk prediction model uses easily obtainable clinical metrics that allow for informed discussion of wound complication risk for patients undergoing open infrainguinal revascularization.

Percutaneous radial artery access for peripheral vascular interventions is a safe alternative for upper extremity access.

OBJECTIVE: Percutaneous radial artery access has been increasingly used for peripheral vascular interventions (PVIs). Our goal was to characterize the practice patterns and perioperative outcomes among patients treated using PVI performed via radial artery access. METHODS: The Vascular Quality Initiative was queried from 2016 to 2020 for PVI performed via upper extremity access. Univariable and multivariable analyses were used to evaluate the periprocedure outcomes of radial artery access cases. A separate sample of brachial artery access cases was used as a comparator. RESULTS: A total of 520 radial artery access cases were identified. The mean age was 69 ± 10 years, and 41.3% were women. Most procedures were performed in the hospital outpatient setting (71.7%). The sheath size was ≤5F for 10%, 6F for 78%, and 7F for 12%. Ultrasound-guided access and protamine were used in 68.3% and 17.3% of cases, respectively. The interventions were aortoiliac (55%), femoropopliteal (55%), and infrapopliteal (9%). Stenting and atherectomy were performed in 55% and 19% of cases, respectively, and more often with 7F sheaths. Access site complications were any hematoma (4.8%), including hematomas resulting in intervention (0.8%), pseudoaneurysms (1%), and access stenosis or occlusion (0.8%). On multivariable analysis, sheath size was not associated with access site complications. Percutaneous brachial artery access (n = 1135) compared with radial access was independently associated with more overall hematomas (odds ratio, 1.73; 95% confidence interval, 1.06-2.81; P = .03). However, access type was not associated with hematomas resulting in intervention (odds ratio, 2.15; 95% confidence interval, 0.69-6.72; P = .19). CONCLUSIONS: PVIs via radial artery access exhibited a low prevalence of postprocedural access site complications and were associated with fewer minor hematoma complications compared with interventions performed using brachial artery access. Radial artery access compared with brachial artery access should be the preferred technique for PVIs.

Risk prediction of 30-day mortality after lower extremity major amputation.

OBJECTIVE: Universal risk calculators may underestimate mortality risk, whereas purely observational administrative data may lack appropriate granularity to individualize risk. The purpose of this study was to create a simple risk prediction model to identify the factors associated with 30-day morality after lower extremity major amputation for ischemic vascular disease. METHODS: The Veterans Affairs Surgical Quality Improvement Program national data set was queried from 2005 to 2015 to identify 14,890 patients undergoing elective above-knee or below-knee amputation for rest pain, tissue loss, or gangrene. The data set was divided into a two-thirds derivation set and one-third validation set for the purpose of creating a risk prediction model. The primary end point was 30-day mortality. Eight independent risk factors for mortality resulted from the model and were assigned whole number integer risk scores. Summary risk scores were collapsed into categories and defined as low (0-3 points), moderate (4-7 points), high (8-10), and very high (>10). RESULTS: Mortality in the derivation data set was 4.6% (n = 453). By multivariable backward elimination, predictors of 30-day mortality (odds ratio [95% confidence limits]) included preoperative do not resuscitate order (3.1 [2.3-4.0]), congestive heart failure (2.8 [2.1-3.6]), age >80 years (1.8 [1.4-2.2]), chronic renal insufficiency (2.1 [1.7-2.5]), above-knee amputation (1.8 [1.4-2.2]), dependent functional status (2.0 [1.6-2.5]), coronary artery disease (1.3 [1.1-1.6]), and chronic obstructive pulmonary disease (1.3 [1.0-1.6]); the final model held a C statistic of 0.74. In both the derivation and validation sets, 30-day mortality correlated with risk category. Among the defined categories in the derivation set, 30-day mortality rates were 2.3% for low-risk patients, 4.3% for moderate-risk patients, 7.5% for high-risk patients, and 17.5% for very-high-risk patients, with similar results for the validation data set. CONCLUSIONS: This risk prediction model uses eight easily obtainable clinical metrics that allow early assessment of 30-day mortality risk of patients undergoing major lower extremity amputation for ischemic indications. The internal validation of the risk score demonstrates the increased mortality with increasing risk category. Reliable expected mortality prediction is critically important for surgeons to make recommendations in accordance with a patient's or family's goals of care. These data may also be used to set realistic expectations for hospital-based quality initiatives and to provide guidance in preoperative medical optimization.

MARCKS silencing differentially affects human vascular smooth muscle and endothelial cell phenotypes to inhibit neointimal hyperplasia in saphenous vein.

Intimal hyperplasia (IH) limits the patency of all cardiovascular vein bypass grafts. We previously found the myristoylated alanine-rich C kinase substrate (MARCKS), a key protein kinase C (PKC) substrate, to be up-regulated in canine models of IH. Here, we further characterize the role of MARCKS in IH and examine the phenotypic consequences of MARCKS silencing by small interfering RNA (siRNA) transfection in human vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) in vitro and use a rapid 10-min nonviral siRNA transfection technique to determine the effects of MARCKS silencing in human saphenous vein cultured ex vivo. We demonstrate MARCKS silencing attenuates VSMC migration and arrests VSMC proliferation in part through the up-regulation of the cyclin-dependent kinase inhibitor p27(kip1). Conversely, MARCKS silencing had little or no effect on EC migration or proliferation. These phenotypic changes culminated in reduced neointimal formation in cultured human saphenous vein. These data identify MARCKS as a pathogenic contributor to IH and indicate therapeutic MARCKS silencing could selectively suppress the "atherogenic," proliferative phenotype of VSMCs without collateral harm to the endothelium. This approach could be readily translated to the clinic to silence MARCKS in vein bypass grafts prior to implantation.

National outcomes after open repair of abdominal aortic aneurysms with visceral or renal bypass.

BACKGROUND: We evaluated national outcomes after open repair of abdominal aortic aneurysms (AAAs) with visceral or renal bypass (VRB). METHODS: Using the National Inpatient Sample database from 1993 through 2006, AAA repairs were identified by ICD9 codes for diagnosis of intact AAA combined with a procedure of open AAA repair. VRB patients also had an aortorenal and/or mesenteric bypass or mesenteric endarterectomy. Dissections as well as thoracic and thoracoabdominal aneurysms were excluded. Demographics and comorbidities were noted. Mortality and complications were compared to infrarenal AAA (IRA) repairs without VRB. Predictors of perioperative mortality were analyzed by multivariate logistic regression. RESULTS: A total of 41,166 VRB and 362,808 IRA repairs were identified. VRB repair volume decreased by 58% and IRA volume decreased by 59% from 1993 to 2006. VRB patients had higher mortality (5.8% vs. 4.4%, p < 0.001) and more complications including acute renal failure (9.5% vs. 6.0%, p < 0.001), acute mesenteric ischemia (2.0% vs. 1.2%), and bowel resection (1.1% vs. 0.8%, p < 0.01). Patients requiring a bowel resection or with acute renal failure were 10 times more likely to die within the hospital stay regardless of repair type. Independent preoperative predictors of mortality were VRB (odds ratio [OR] = 1.3, 95% confidence interval [CI] 1.2-1.5), age (OR = 1.4 per decade, 95% CI 1.4-1.5), chronic renal failure (OR = 5.5, 95% CI 4.9-6.3), congestive heart failure (OR = 7.5, 95% CI 6.1-9.3), and pulmonary disease (OR = 1.2, 95% CI 1.1-1.2). CONCLUSION: VRB repair volume decreased per year similarly to open IRA repair volume and may be related to increasing use of endovascular therapy. Mortality after VRB is high and dependent upon age, renal failure, and congestive heart failure. Overall, VRB repair was associated with worsened outcomes; however, this study cannot conclude that avoiding such a repair will improve outcomes. This should be factored into surgical decision making for these patients.

Asymptomatic portal vein aneurysms: To treat, or not to treat?

Background Portal vein aneurysms are rare dilations in the portal venous system, for which the etiology and pathophysiological consequences are poorly understood. Method We reviewed the existing literature as well as present a unique anecdotal case of a patient presenting with a very large portal vein aneurysm that was successfully managed conservatively and non-operatively without anticoagulation, with close follow-up and routine surveillance. Result The rising prevalence of abdominal imaging in clinical practice has increased rates of portal vein aneurysm detection. While asymptomatic aneurysms less than 3 cm can be clinically observed, surgical intervention may be necessary in large asymptomatic aneurysms (>3 cm) with or without thrombus, or small aneurysms with evidence of evolving mural thrombus formation on imaging. Conclusion Portal vein aneurysms present a diagnostic challenge for any surgeon, and the goal for surgical therapy is based on repairing the portal vein aneurysm, and if portal hypertension is present decompressing via surgically constructed shunts.