Risk factors of nonretrieval of retrievable inferior vena cava filters.

BACKGROUND: Optimal use of retrievable inferior vena cava (IVC) filters is an important health care issue, and despite an exponential rise in the use of retrievable IVC filters, national trends suggest that most of these filters are not removed. The purpose of this study was to identify risk factors associated with nonretrieval of retrievable IVC filters at our institution. METHODS: A retrospective institutional review of all patients undergoing IVC filter placement from June 2010 to June 2012 was performed. A number of patient parameters were studied, including relevant demographics, indication for filter placement, clinical history, related hospitalization, and whether filter retrieval was performed. Patient parameters were compared by univariate and multivariate logistic regression analyses. RESULTS: There were 605 retrievable IVC filters placed over a 24-month period by vascular surgery, intervention radiology, and interventional cardiology. The follow-up retrieval rate was 25%. By indication, 272 (45%), 53 (9%), and 280 (46%) filters were placed for absolute, relative, and prophylactic indications, respectively. Independent predictors for nonretrieval by multivariate analysis were age >80 years (hazard ratio [HR], 5.0; 95% confidence interval [CI], 1.7-20; P < 0.001), acute bleed (HR, 2.5; 95% CI, 1.4-5; P < 0.001), current malignancy (HR, 2.0; 95% CI, 1.3-3.3; P = 0.011), postfilter anticoagulation (HR, 0.5; 95% CI, 0.28-0.9; P = 0.017), and history of pulmonary embolism and/or venous thromboembolism (HR, 0.5; 95% CI, 0.28-0.35; P < 0.001). Filter placement team and indication were not identified as independent predictors of nonretrieval of IVC filters. CONCLUSIONS: Patient variables identified by univariate and multivariate analyses as risk for nonretrieval of retrievable IVC filters have several implications: first, some of these patients may represent a group of patients with a low life expectancy or unresolvable underlying condition in which filter retrieval has diminishing returns and may indicate the clinical option for permanence of the filter; second, identification of risk factors for nonretrieval in patients before filter placement will help to optimize use of retrievable IVC filters and enhance retrieval rates.

Complications of the endovascular management of acute ischemic stroke.

Acute ischemic stroke is a significant source of morbidity and mortality across the globe. Currently, the only US Food and Drug Administration approved medical treatment of acute ischemic stroke is intravascular (IV) alteplase. While IV thrombolysis has been shown to decrease morbidity and mortality from acute ischemic stroke, it is limited in both its efficacy in certain types of stroke, as well as in its generalizability. It has been shown that time to revascularization is one of the most important predictors of outcomes in acute ischemic stroke, and thus clinicians have turned to endovascular options in efforts to improve outcomes from stroke. Direct intra-arterial thrombolysis was one of the first of such efforts to improve efficacy rates and increase the timeline for thrombolytic therapy. More recently, investigators and clinicians have turned to newer endovascular options in attempts to further improve recanalization rates. Many different endovascular techniques have been employed and are growing exponentially in use. Examples include stenting, as well as mechanical thrombectomy with both older-generation devices and newer stent retrieval technology. While the majority of the literature focuses on the effectiveness of different techniques, such as recanalization rates and major overall outcomes such as death and disability, there is very little literature on the complications of the different techniques. The purpose of this article is to review the different forms of endovascular treatment of acute ischemic stroke and their associated complications.

Defining risks and predicting adverse events after lower extremity bypass for critical limb ischemia.

Successful treatment of patients with critical limb ischemia (CLI), hinges on the adequacy of revascularization. However, CLI is associated with a severe burden of systemic atherosclerosis, and patients often suffer from multiple cardiovascular comorbidities. Therefore, CLI patients in general represent a cohort at increased risk for procedural complications and adverse events. Although endovascular therapy represents a minimally invasive alternative to open surgical bypass, the durability of surgical reconstruction is superior, and it remains the "gold standard" approach to revascularization in CLI. Therefore, selection of the optimal treatment modality for individual patients requires careful consideration of the procedural risks and likelihood of adverse events associated with surgery. Individualized decision-making with regard to revascularization strategy requires a comprehensive understanding of the likelihood of adverse outcomes after major surgery. Here we review the risks of surgical bypass in patients with CLI, with particular emphasis on the identification of preoperative variables that predict poor outcome.

Variability in anesthetic considerations for arteriovenous fistula creation.

INTRODUCTION: Anesthetic options for arteriovenous fistula (AVF) creation include regional anesthesia (RA), general anesthesia (GA) and local anesthetic for select cases. In addition to the benefits of avoiding GA in high-risk patients, recent studies suggest that RA may increase perioperative venous dilation and improve maturation. Our objective was to assess perioperative outcomes of AVF creation with respect to anesthetic modality and identify patient-level factors associated with variation in contemporary anesthetic selection. METHODS: National Surgical Quality Improvement Project (NSQIP) data (2007-2010) were accessed to identify patients undergoing AVF creation. Univariate analysis and multivariate logistic regression were performed to assess the relationships among patient characteristics, anesthesia modality and outcome. RESULTS: Of 1,540 patients undergoing new upper extremity AVF creation, 52% were male and 81% were younger than 75 years. Anesthesia distribution was GA in 85.2%, local/monitored anesthetic care (MAC) in 2.9% and RA in 11.9% of cases. By multivariate analysis, independent predictors of RA were dyspnea at rest (hazard ratio [HR] 2.3, 95% confidence interval [CI] 1.1-4.9), age >75 (HR 1.6, 95% CI 1.1-2.3) and teaching hospital status as indicated by housestaff involvement (HR 3.7, 95% CI 2.5-5.5). RA was associated with higher total operative time, duration of anesthesia, length of time in operating room and duration of anesthesia start until surgery start (p<0.01). There were no differences between perioperative complications or mortality among anesthetic modalities, although all deaths occurred in the GA group. DISCUSSIONS: Despite recent reports highlighting potential benefits of RA for AVF creation, GA was surprisingly used in the vast majority of cases in the United States. The only comorbidities associated with preferential RA use were advanced age and dyspnea at rest. Practice environment may influence anesthetic selection for these cases, as a nonteaching environment was associated with GA use. The trend seen here toward higher mortality in GA and the potential perioperative benefits of RA for the access should encourage more widespread use of RA in practice for this high-risk patient population.

Endovascular treatment of lesions in the below-knee popliteal artery.

BACKGROUND: Endovascular interventions are increasing; however, there are little data regarding outcomes of complex interventions involving the below-knee popliteal/P3 artery. This study evaluated the short-term and long-term results and predictors of success of below-knee popliteal artery endovascular interventions. METHODS: This was a retrospective review of a prospectively maintained endovascular lower extremity database of all patients with below-knee popliteal interventions from 2004 to 2012. Patient demographics, angiographic findings, interventions, primary and secondary patency, limb loss, and mortality were recorded. Analysis was performed using Kaplan-Meier life-table and multivariate analysis, with P < .05 indicating significance. RESULTS: There were 221 patients (56% male) with below-knee popliteal/P3 artery lesions. Mean age was 73 ± 11.2 years. Claudication was present in 22% and critical limb ischemia (CLI) in 78%. Mean lesion length was 10 ± 8.5 cm, with 45% having total occlusions. Treatment included percutaneous transluminal angioplasty (PTA) with or without a stent (47%), atherectomy (ATH) with or without PTA/stent (52%), and stenting with PTA and ATH (3%). Complications included embolization (0.4%), hematoma (2.7%), pseudoaneurysm (1.3%), and dissection (7%). Freedom from restenosis (peak systolic velocity ratio >2.4) was 65% at 1 year. Independent predictors of restenosis were CLI (hazard risk [HR], 4.4; 95% confidence interval [CI], 1.9-9.9) and stenting combined with PTA and ATH (HR, 2.7; 95% CI, 1.01-7.4). Primary assisted and secondary patencies were 95% and 85% at 1 year. ATH with PTA had lower short-term restenosis in diabetic patients compared with nondiabetic patients (95% vs 78% at 4 months). Limb loss was 18% at 4 years. Mortality was 24% at 4 years. Statin use was protective against primary restenosis (HR, 0.39; 95% CI, 0.23-0.67) and death (HR, 0.5; 95% CI, 0.28-1.0). CONCLUSIONS: Endovascular intervention for lesions involving the below-knee popliteal artery is a safe and effective therapy for claudication and CLI. Diabetic patients benefit most from ATH with PTA. Statin use is protective against restenosis and mortality and should be the standard of care in patients undergoing peripheral endovascular interventions.

Risk factors for protracted postoperative length of stay after lower extremity bypass for critical limb ischemia.

BACKGROUND: Compared with other common chronic conditions, admissions for management of peripheral arterial disease (PAD) are associated with prolonged hospitalizations. Length of stay (LOS) is one of many metrics receiving increased attention in the current focus on efficient healthcare delivery. Our objective was to characterize LOS among patients with severe PAD, those undergoing surgical bypass for critical limb ischemia (CLI), and identify risk factors for protracted postoperative LOS. METHODS: Patient data from the 2007 to 2009 American College of Surgeons National Surgical Quality Improvement Program were used to develop a database consisting of patients undergoing bypass surgery for CLI (n = 4,894). Protracted postoperative LOS was defined as the top quartile of days hospitalized from surgery to discharge. Preoperative risk factors with significant association (Pearson chi-squared test; P < 0.05) were used to develop a logistic regression model for protracted postoperative LOS. RESULTS: Average postoperative LOS was 7.5 days (median 6 days). The top quartile of postoperative LOS, >8 days, was used to define protracted LOS. Independent preoperative risk factors for protracted postoperative LOS included demographic characteristics (advanced age and non-Caucasian race), comorbidities, and medical history (e.g., obesity, dialysis dependence, severe cardiac and pulmonary disease, and bleeding disorders). Indicators of PAD severity (e.g., distal target sites, open wounds or gangrene, and prior arterial surgery) were also independent predictors of protracted LOS after surgery. The greatest predictors of extended postoperative LOS were prolonged preoperative hospitalization (OR 2.2 [95% CI: 1.8-2.6], P < 0.001) and preoperative dependent functional status (OR 2.0 [95% CI: 1.7-2.3], P < 0.001 for partial dependence; OR 2.8 [95% CI: 1.8-4.3], P < 0.001 for totally dependent status), where OR and CI stand for odds ratio and confidence interval. CONCLUSIONS: Here, we identify preoperative risk factors for protracted postoperative LOS after infrainguinal bypass for CLI. These findings provide an important evidence basis for ongoing efforts to reduce healthcare spending and facilitate provision of efficient health care. Future efforts will include prospective identification of patients at high risk for protracted postoperative LOS and targeted multidisciplinary efforts to reduce associated costs without sacrificing healthcare quality.