Lower Extremity Endovascular Interventions Research Articles

Impact of Glycoprotein IIb/IIIa Inhibitors Use on Outcomes After Lower Extremity Endovascular Interventions From Nationwide Inpatient Sample (2006-2011).

The aim of our study was to study the impact of glycoprotein IIb/IIIa inhibitors (GPI) on in-hospital outcomes. There is paucity of data regarding the impact of GPI on the outcomes following peripheral endovascular interventions. The study cohort was derived from Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS) database between the years 2006 and 2011. Peripheral endovascular interventions and GPI utilization were identified using appropriate ICD-9 Diagnostic and procedural codes. Two-level hierarchical multivariate mixed models were created. The study outcomes were: primary (in-hospital mortality and amputation studied separately) and secondary (composite of in-hospital mortality and postprocedural complications). Hospitalization costs were also assessed. GPI utilization (OR, 95% CI, P-value) was independently predictive of lower amputation rates (0.36, 0.27-0.49, <0.001). There was no significant difference in terms of in-hospital mortality (0.59, 0.31-1.14, P 0.117), although GPI use predicted worse secondary outcomes (1.23, 1.03-1.47, 0.023). Following propensity matching, the amputation rate was lower (3.2% vs. 8%, P < 0.001), while hospitalization costs were higher in the cohort that received GPI ($21,091 ± 404 vs. 19,407 ± 133, P < 0.001). Multivariate analysis revealed GPI use in peripheral endovascular interventions to be suggestive of an increase in composite end-point of in-hospital mortality and postprocedural complications, no impact on in-hospital mortality alone, significantly lower rate of amputation, and increase in hospitalization costs. © 2016 Wiley Periodicals, Inc.

Acute Lower Extremity Paralysis After Lower Extremity Endovascular Intervention

A 61-year-old man underwent successful percutaneous revascularization of both lower limbs with multiple stent implantations. Paralysis of right lower limb was noticed after completion of procedure when transferring the patient from angiography table. Since hematoma compressing lumbosacral neural plexus could be a fatal complication, computed tomography (CT) image was taken. CT showed bulge of distended bladder compressing stent struts. Following placement of Foley catheter, condition improved and he was subsequently discharged uneventfully.

Abstract 15184: Prevalence, Predictors and Clinical Outcomes of Unknown Coronary Artery Disease Among the Patients Undergoing Lower Extremity Endovascular Intervention

Introduction: The prevalence and clinical outcomes of unknown coronary artery disease (CAD) among the patients with peripheral artery disease, particularly for those undergoing lower extremity endovascular intervention, were not well evaluated. Methods: Between 2006 and 2014, a total of 208 consecutive patients (73±10 years, 165 men) without angina and prior coronary revascularization, were underwent lower extremity endovascular intervention. All patients evaluated coronary angiography without simutaneous coronary revascularization. CAD was defined as angiographically significant (≥50%) stenosis. All-cause mortality and major adverse cardiac and cerebrovascular event (MACCE) rate were compared between the patients with CAD and those without CAD. MACCE included cardiac death, cerebrovascular death, myocardial infarction, stroke, or heart failure. Results: Of the 208 patients, 103 patients (50%) had CAD; 1-VD (17%); 2-VD (17%); 3-VD (15%). Independent predictors of CAD were critical limb ischemia (OR=2.4) and below-the-knee lesions (OR=2.0). During the median follow-up of 1.2 years, all-cause mortality and MACCE rate at 3 year were 16.3% and 19.8%. At 3 year, patients with CAD had significantly higher mortality (19% vs. 14%, P=0.018) and higher MACCE rate (28% vs. 9%, P=0.001) compared to those without CAD. The severity of CAD had graded relations with the mortality and MACCE rate (Figure). Presence of CAD was an independent predictor of mortality (HR=1.5, P=0.025) and MACCE rate (HR=1.9, P&lt;0.001). Conclusions: Previously unknown CAD was detected in half of the patients undergoing lower extremity endovascular intervention and associated with higher mortality and MACCE rate. Detection of CAD might be important for risk stratification for these patients, especially with below-the-knee lesions.

Distal Embolization During Lower Extremity Endovascular Interventions

Distal embolization (DE) during peripheral arterial endovascular interventions is a well-known complication that is poorly studied. The goal of this project was to determine the incidence, risk factors, and effect of DE on the outcomes of lower extremity endovascular interventions (LEI). All LEI between 2010 and 2014 in the Vascular Study Group of New England database were reviewed. Patient characteristics were analyzed to determine predictors of DE. LEI involving the superficial femoral artery (SFA) were reviewed to assess the effect of type of treatment on DE. The outcomes examined were loss of patency, limb loss, and mortality after LEI involving the SFA. A multivariable regression was used to determine predictors of DE. SAS and STAT 9.4 software were used for all analyses. There were a total of 10,856 procedures. The incidence of DE was 17.3/1000 procedures, and 68% required treatment (57% endovascular, 11% open surgery). DE was more common in patients with diabetes (relative risk [RR], 1.51; 95% confidence interval [CI], 1.11-2.04), and in urgent (RR, 1.91; 95% CI, 1.37-2.66) and emergency (RR, 3.43; 95% CI, 1.77-6.67) procedures compared with elective procedures. The use of aspirin/P2Y12 antagonists and statins were associated with lower incidence of DE (RR, 0.65; 95% CI, 0.46-0.92; RR, 0.66; 95% CI, 0.49-0.90, respectively). DE increased with the number of arteries treated (P < .0001), and with the length of occlusion (P < .0001). The SFA was the most commonly treated artery (4751 [43.7%]). The combined treatment modalities of balloon angioplasty and atherectomy as well as stenting and atherectomy had higher risk of DE compared with balloon angioplasty and stenting of the SFA (RR, 3.20; 95% CI, 1.91-5.37; RR, 3.15; 95% CI, 1.62-6.12, respectively). DE was not significantly associated with loss of patency, major amputation, or mortality. The incidence of DE during LEI is 1% to 2% and increases with atherectomy. The use of platelet inhibitors and statins seems to be protective.

Retrospective review of superficial femoral artery stenting in diabetic patients: thiazolidinedione use may decrease reinterventions.

BackgroundDiabetics are known to have inferior outcomes following peripheral vascular interventions. Thiazolidinediones are oral diabetic agents which improve outcomes following coronary bare metal stenting. No studies have been performed evaluating thiazolidinedione use and outcomes following lower extremity endovascular interventions. We hypothesize that diabetic patients taking thiazolidinediones at the time of primary superficial femoral artery (SFA) stenting have fewer reinterventions.MethodsA retrospective review was performed to identify diabetic patients undergoing primary SFA stenting. The unit of analysis was the extremity. The primary outcome was freedom from target lesion revascularization stratified by thiazolidinedione use, evaluated by Kaplan Meier curves and a log rank test. A Cox proportional hazards model was constructed to determine variables associated with freedom from target lesion revascularization.ResultsSFA stents were placed in 138 extremities in 128 diabetic patients between August 1, 2001 and July 15, 2012. Twenty-four patients were taking thiazolidinediones at the time of SFA stenting. All patients taking thiazolidinediones had TASC A or B lesions. Twenty-seven extremities in the non-thiazolidinedione group had TASC C or D lesions and were excluded to control for disease severity. Freedom from target lesion revascularization was significantly higher in diabetics taking thiazolidinediones at 2 years, 88.5% vs. 59.4%, P = 0.02, SE < 10%. Cox modeling identified a protective trend for thiazolidinedione use (thiazolidinedione use HR 0.33, 95% CI 0.09-1.13), whereas critical limb ischemia and insulin use were associated with trends for worse freedom from target lesion revascularization.ConclusionsThis pilot, translation study demonstrates that diabetic patients taking thiazolidinediones at the time of primary SFA stenting have decreased reintervention rates at 2 years. These results may be explained by higher adiponectin levels or other anti-inflammatory effects in patients taking thiazolidinedione. National and regional quality improvement registries should consider collecting information regarding specific diabetic regimens and use of PPAR agonists such as cilostazol and fibrates.

C-reactive protein and brain natriuretic peptide as predictors of adverse events after lower extremity endovascular revascularization

High-sensitivity C-reactive protein (hsCRP) and brain natriuretic peptide (BNP) have been shown to be independent predictors of adverse cardiovascular outcomes and increased risk of secondary interventions or limb loss in patients with peripheral arterial disease (PAD). To assist clinicians in decision-making about treatment approaches and predicting postprocedure mortality and morbidity, we retrospectively examined patients with preprocedure hsCRP and BNP levels who underwent elective angioplasty or stent placement for lower extremity PAD. The study period was from January 1, 2007, to December 31, 2012, and patients were included who had angioplasty or stenting for PAD. Minimal required follow-up for study inclusion was at least one postoperative ankle-brachial index, contrast angiography, or duplex imaging of the treated limb. Events of interest included major adverse limb events (MALE), defined as target vessel revascularization, amputation, or disease progression by 1 year, and major adverse cardiovascular events (MACE; stroke, myocardial infarction, or death) by 2 years. Elevated/abnormal values for our biomarkers of interest were established by the upper limits of our institution's clinical laboratory reference range (hsCRP, >0.80 mg/dL; BNP, >100 pg/mL). A total of 159 limbs in 118 patients were included in analysis (42% men; median age [range], 64 [42-87] years). All limbs were symptomatic (Rutherford classification: 1-6). Iliac artery revascularization without other adjunct lower extremity intervention was performed in 60% of the limbs. High hsCRP levels (>0.80 mg/dL) were present in 32 patients (27%) and high BNP values (>100 pg/mL) in 24 patients (20%). Kaplan-Meier analysis with log-rank comparison demonstrated that elevated hsCRP levels were associated with MALE but only in limbs receiving interventions distal to the iliac arteries (P = .005). High BNP levels did not affect MALE rates (P = .821). Conversely, both elevated BNP levels (hazard ratio, 5.6; 95% confidence interval [CI], 2.0-5.8; P = .001) and hsCRP levels (hazard ratio, 2.9; 95% CI, 1.1-7.6; P = .034) predicted MACE at 2 years in the presence of confounders in Cox proportional hazards multivariate analysis. Patients with high preintervention values of hsCRP and BNP were 10.6 times (95% CI, 2.6-42.9; P = .001) more likely to experience MACE than were patients with normal hsCRP and BNP values. After lower extremity endovascular interventions, elevated preprocedural hsCRP levels are associated with MALE (femoral-popliteal interventions), and elevated levels of hsCRP and BNP are associated with late cardiovascular events.

Duplex Evaluation Following Femoropopliteal Angioplasty and Stenting: Criteria and Utility of Surveillance

Surveillance following lower extremity bypass, carotid endarterectomy, and endovascular aortic aneurysm repair has become the standard of care at most institutions. Conversely, surveillance following lower extremity endovascular interventions is performed somewhat sporadically in part because the duplex criteria for recurrent stenoses have been ill defined. It appears that duplex surveillance after peripheral endovascular interventions, as with conventional bypass, is beneficial in identifying recurrent lesions which may preclude failure and occlusion. In-stent stenosis following superficial femoral artery angioplasty and stenting can be predicted by both peak systolic velocity and velocity ratio data as measured by duplex ultrasound. Duplex criteria have been defined to determine both ≥50% in-stent stenosis and ≥80% in-stent stenosis. Although not yet well studied, it appears that applying these criteria during routine surveillance may assist in preventing failure of endovascular interventions.

National trends in lower extremity bypass surgery, endovascular interventions, and major amputations

Advances in endovascular interventions have expanded the options available for the invasive treatment of lower extremity peripheral arterial disease (PAD). Whether endovascular interventions substitute for conventional bypass surgery or are simply additive has not been investigated, and their effect on amputation rates is unknown. We sought to analyze trends in lower extremity endovascular interventions (angioplasty and atherectomy), lower extremity bypass surgery, and major amputation (above and below-knee) in Medicare beneficiaries between 1996 and 2006. We used 100% samples of Medicare Part B claims to calculate annual procedure rates of lower extremity bypass surgery, endovascular interventions (angioplasty and atherectomy), and major amputation between 1996 and 2006. Using physician specialty identifiers, we also examined trends in the specialty performing the primary procedure. Between 1996 and 2006, the rate of major lower extremity amputation declined significantly (263 to 188 per 100,000; risk ratio [RR] 0.71, 95% confidence interval [CI] 0.6-0.8). Endovascular interventions increased more than threefold (from 138 to 455 per 100,000; RR = 3.30; 95% CI: 2.9-3.7) while bypass surgery decreased by 42% (219 to 126 per 100,000; RR = 0.58; 95% CI: 0.5-0.7). The increase in endovascular interventions consisted both of a growth in peripheral angioplasty (from 135 to 337 procedures per 100,000; RR = 2.49; 95% CI: 2.2-2.8) and the advent of percutaneous atherectomy (from 3 to 118 per 100,000; RR = 43.12; 95% CI: 34.8-52.0). While radiologists performed the majority of endovascular interventions in 1996, more than 80% were performed by cardiologists and vascular surgeons by 2006. Overall, the total number of all lower extremity vascular procedures almost doubled over the decade (from 357 to 581 per 100,000; RR = 1.63; 95% CI: 1.5-1.8). Endovascular interventions are now performed much more commonly than bypass surgery in the treatment of lower extremity PAD. These changes far exceed simple substitution, as more than three additional endovascular interventions were performed for every one procedure declined in lower extremity bypass surgery. During this same time period, major lower extremity amputation rates have fallen by more than 25%. However, further study is needed before any causal link can be established between lower extremity vascular procedures and improved rates of limb salvage in patients with PAD.

Invited commentary

Invited commentary

Lower extremity endovascular interventions: Can we improve cost-efficiency?

Management of lower extremity arterial disease with endovascular intervention is on the rise. Current practice patterns vary widely across and within specialty practices that perform endovascular intervention. This study evaluated reimbursement and costs of different approaches for offering endovascular intervention and identified strategies to improve cost-efficiency. The medical records of all patients admitted to a university health system during 2005 for an endovascular intervention were retrospectively reviewed. Procedure type, setting, admission status, and financial data were recorded. Groups were compared using analysis of variance, Student t test for independent samples, and chi2. A total of 296 endovascular interventions were completed, and 184 (62%) met inclusion criteria. Atherectomy and stenting were significantly more costly when performed in the operating room than in the radiology suite: atherectomy, dollars 6596 vs dollars 4867 (P = .002); stent, dollars 5884 vs dollars 3292, (P < .001); angioplasty, dollars 2251 vs dollars 1881 (P = .46). Reimbursement was significantly higher for inpatient vs ambulatory admissions (P < .001). Costs were lowest when the endovascular intervention was done in the radiology suite on an ambulatory basis and highest when done as an inpatient in the operating room (dollars 5714 vs dollars 12,278; P < .001). Contribution margins were significantly higher for inpatients. Net profit was appreciated only for interventions done as an inpatient in the radiology suite. Reimbursement, contribution margins, and net profit were significantly lower among private pay patients in both the ambulatory and inpatient setting. The 30-day hospital readmission after ambulatory procedures was seven patients (6%). Practice patterns for endovascular interventions differ considerably. Costs vary by procedure and setting, and reimbursement depends on admission status and accurate documentation; these dynamics affect affordability. Organizing vascular services within a hub will ensure that care is delivered in the most cost-efficient manner. Guidelines may include designating the radiology suite as the primary venue for endovascular interventions because it is less costly than the operating room. Selective stenting policies should be considered. Contracts with private insurers must include carve-outs for stent costs and commensurate reimbursement for ambulatory procedures, and Current Procedural Terminology (CPT; American Medical Association, Chicago, Ill) coding must be proficient to make ambulatory endovascular interventions fiscally acceptable.

Commentary on "Duplex Surveillance of Lower Extremity Endovascular Interventions"

Commentary on "Duplex Surveillance of Lower Extremity Endovascular Interventions"

Update on Lower Extremity Endovascular Interventions

In the past decade there have been major strides in the development of devices and techniques for nonsurgical lower extremity revascularization. These advances have broadened indications for endovascular therapies and expanded the treatment options for patients with peripheral vascular disease. A variety of new laser‐etched steel and nitinol stent designs now complement balloon angioplasty. In the iliac segment, stenting has replaced balloon angioplasty as the first‐line therapy for treatment of symptomatic occlusive disease. Stenting results in superior acute procedural success and long‐term clinical efficacy compared to balloon angioplasty and is a “less invasive” alternative to surgical reconstruction. Endoluminal stent grafts offer promise in the treatment of high‐risk patients with abdominal aortic aneurysms. New strategies are being developed to address the diverse nature of the superficial femoral artery (SFA) and infrapopliteal disease where balloon angioplasty, stenting, and stent graft strategies have proven unsatisfactory for treatment of diffuse disease and long occlusions. The next millennium will see the use of “therapeutic angiogenesis,” the intravascular and intramuscular administration of DNA fragments or proteins, to stimulate new vessel growth in patients not amenable to conventional surgical or endovascular therapies. Brachytherapy, the intravascular delivery of a retrievable ionizing radiation source, represents an exciting development that offers the potential of reducing restenosis in the SFA.