Panos Kougias

The system of care for the diabetic foot: objectives, outcomes, and opportunities

Most cases of lower extremity limb loss in the United States occur among people with diabetes who have a diabetic foot ulcer (DFU). These DFUs and the associated limb loss that may occur lead to excess healthcare costs and have a large negative impact on mobility, psychosocial well-being, and quality of life. The strategies for DFU prevention and management are evolving, but the implementation of these prevention and management strategies remains challenging. Barriers to implementation include poor access to primary medical care; patient beliefs and lack of adherence to medical advice; delays in DFU recognition; limited healthcare resources and practice heterogeneity of specialists. Herein, we review the contemporary outcomes of DFU prevention and management to provide a framework for prioritizing quality improvement efforts within a resource-limited healthcare environment.

Patients with severe chronic kidney disease benefit from early revascularization after acute coronary syndrome

BACKGROUND Early revascularization is associated with improved outcomes after non-ST-elevation acute coronary syndrome (ACS). It is unclear whether its benefits exist in patients with ACS and advanced chronic kidney disease (CKD), because these patients are often sub-optimally treated and excluded from clinical trials. METHODS We undertook meta-analyses of short- and long-term mortality outcomes in comparative studies examining the effectiveness of early revascularization in patients with ACS and CKD (as estimated by Glomerular Filtration Rate, eGFR). A literature search between 1995 and 2010 identified 7 published reports enrolling 23,234 patients with at least mild reduction in eGFR (<90 mL/min/1.73 m(2)), of whom 6276 and 16,958 patients received early revascularization versus initial medical therapy, respectively. Summary odds ratios (OR) and their 95% Confidence Intervals (CIs) were calculated using the random-effects models. Sensitivity analyses were performed by one-study removal, and publication bias was assessed by the funnel plot analysis. RESULTS Early revascularization was associated with a reduction in 1-year mortality compared to initial medical therapy (OR=0.46, 95% CI 0.26-0.82, P=0.008) among ACS patients with eGFR<60 mL/min/1.73 m(2). The mortality reduction with early revascularization occurred upfront (short term mortality OR=0.69, 95% CI 0.56-0.87, P=0.001), persisted at 3 years (OR=0.54, 95% CI 0.31-0.96, P=0.037), was evident across all CKD stages (including dialysis patients), and was independent of the influence of any single study. CONCLUSIONS Early revascularization after ACS is associated with reduced mortality in appropriately-selected patients with CKD, including those with severe CKD or receiving dialysis.

Carotid artery stenting with distal protection using the carotid wallstent and filterwire neuroprotection: single-center experience of 380 cases with midterm outcomes.

Emerging data have supported the clinical efficacy of carotid artery stenting (CAS) in stroke prevention in high-risk surgical patients. This study was performed to evaluate the midterm clinical outcome of CAS using the Carotid Wallstent and FilterWire distal protection (both Boston Scientific, Natick, MA) at an academic institution. Risk factors for in-stent restenosis (ISR) were also analyzed. Clinical variables and treatment outcome of high-risk patients who underwent Carotid Wallstent placement with FilterWire EX/EZ neuroprotection were analyzed during a recent 54-month period. Three hundred eighty CAS procedures were performed in 354 patients. Technical success was achieved in 372 cases (98%), and symptomatic lesions existed in 85 (24%) patients. No patient experienced periprocedural mortality or neuroprotective device–related complication. The 30-day stroke and death rate was 2.7%, and the overall complication rate was 6.9%. The overall major or fatal stroke rates in symptomatic and asymptomatic patients were 4.6% and 1.3%, respectively (not significant). The overall stroke and death rates between the symptomatic and asymptomatic groups were 5.8% and 2.4%, respectively (not significant). The median follow-up period was 29 months (range 1–53 months). With Kaplan-Meier analysis, the rates of freedom from 60% or greater ISR after CAS procedures at 12, 24, 36, and 48 months were 97%, 94%, 92%, and 90%, respectively. The rates of freedom from all fatal and nonfatal strokes at 12, 24, 36, and 48 months were 97%, 91%, 89%, and 85%, respectively. Multivariable analysis of significant univariate predictors identified that postendarterectomy stenosis (odds ratio [OR] 3.98, p = .02) and multiple stent placement (OR 3.68, p = .03) were independent predictors of ISR. Our study yielded favorable short-term and midterm clinical results using Carotid Wallstent with FilterWire neuroprotection. Late follow-up results showed low rates of fatal and nonfatal stroke and favorable ISR rates compared with other carotid stent trials. Postendarterectomy and multiple stent placement were associated with subsequent ISR.

Cost-effectiveness of revascularization for limb preservation in patients with end-stage renal disease

BACKGROUND Limb revascularization in patients with end-stage renal disease (ESRD) has been criticized because of the low rates of limb preservation and overall survival that characterize this patient population. We undertook a formal cost-utility analysis to evaluate the role of revascularization in the ESRD population. METHODS A probabilistic Markov model was used to simulate the clinical outcomes and long-term outcomes after six different strategies for the management of nonhealing foot wounds in patients with critical limb ischemia and ESRD. All scenarios considered all-cause mortality and major amputation for failure of limb salvage. Parameter estimates of the costs, clinical events, and functional outcomes used in the model were derived from primary data or published literature. Costs are reported in 2011 U.S. dollars. RESULTS Local wound care alone had the lowest long-term total cost of the management strategies evaluated; primary amputation had the highest. Purely endovascular intervention yielded the highest limb salvage rates. Endovascular intervention had a cost of

Minor Amputation and Palliative Wound Care as a Strategy to Avoid Major Amputation in Patients With Foot Infections and Severe Peripheral Arterial Disease

15,403 per additional year of ambulation beyond that by local wound care alone. Endovascular intervention had the potential for cost-savings (ie, better health benefits at lower cost) only with very high 1-year wound healing rates. The 5-year survival rates ranged from 17% to 34% in all management strategies. CONCLUSIONS Endovascular intervention may be a cost-effective alternative to local wound care alone for patients with ESRD and ischemic foot wounds, but with small marginal health benefits at considerable cost. Local wound care alone may be preferable to primary amputation.

Establishment of a transcatheter aortic valve program and heart valve team at a Veterans Affairs facility.

Foot infections occurring in patients with severe peripheral arterial disease (PAD) who are not considered candidates for revascularization and limb salvage efforts are generally treated with major amputations. Herein we describe our early experiences in managing foot infections with minor amputations and palliative wound care as a strategy to avoid the functional disability often associated with major amputations. Patients with severe PAD that underwent minor amputations and subsequent palliative wound care for moderate/severe infections were paired with age-matched controls with PAD that underwent primary major amputations for foot infections. Eleven patients who underwent minor amputations and palliative wound care of 13 limbs were compared to an age-matched cohort of 12 patients undergoing 13 major amputations.The median age was 80 years in both groups. Survival at 1 and 2 years did not differ significantly between groups. All patients who were ambulatory and/or independently living remained so following palliative management; in contrast, major amputation changed ambulatory status in 75% of patients and independent living status in 50%. Palliative management did not result in ascending/systemic sepsis or progressive necrosis. The need for reoperations was uncommon in both groups. In summary, minor amputations and operative drainage with subsequent palliative wound care appears to be a safe management option in patients with severe PAD and moderate or severe foot infections that are not candidates for revascularization. Palliative management may result in less functional impairment than major amputation.

Comparison of domain-specific cognitive function after carotid endarterectomy and stenting

BACKGROUND The US Food and Drug Administration recently approved a transcatheter aortic valve for patients for whom open heart surgery is prohibitively risky. METHODS A multidisciplinary heart valve team partnered with administration to launch a transcatheter aortic valve replacement (TAVR) program. Clinical registries were used to show robust valve caseloads and outcomes at our Veterans Affairs (VA) facility and to project future volumes. A TAVR business plan was approved by the VA leadership as part of a multiphase project to upgrade and expand our surgical facilities. RESULTS The heart valve team completed a training program that included simulations and visits to established TAVR centers. Patients were evaluated and screened through a streamlined process, and the program was initiated successfully. CONCLUSIONS Establishing a TAVR program at a VA facility requires a multidisciplinary team with experience in heart valve and endovascular therapies and a supportive administration willing to invest in a sophisticated infrastructure.

Impact of cumulative intravascular contrast exposure on renal function in patients with occlusive and aneurysmal vascular disease

BACKGROUND Observational data indicate that carotid artery stenting (CAS) is associated with higher incidence of subclinical cerebral microemboli than carotid endarterectomy (CEA). We hypothesized that CEA would be associated with superior performance on detailed domain-specific cognitive testing compared with CAS. METHODS Patients with >80% asymptomatic carotid artery stenosis were randomized to CEA or CAS with side of stenosis balanced across condition. A robust battery of tests was used to assess the cognitive domains of attention, memory, mood, visual-spatial skills, motor ability, processing speed, and executive functioning ≤10 days preoperatively and postoperatively at 6 weeks and 6 months. Tests were administered using standardized conditions and were scored by individuals blinded to treatment allocation. RESULTS Baseline cognitive performance was similar between CAS (n = 29) and CEA (n = 31) groups (P > .05). Relative to baseline, verbal and visual memory and attention functions substantially improved in the CAS and CEA groups at 6 months (multiple cognitive tests achieved statistical significance). Compared with CEA, cognitive processing speed (Stroop Color test: 9.0 vs 7.3, P = .04; and Stroop Word test: 9.0 vs 7.4, P = .05) was superior in the CAS group at 6 weeks. Executive functioning (phonemic verbal fluency: 10.6 vs 8.4, P = .043) and motor function (Grooved Pegboard of nondominant extremity: 45.7 vs 38.9, P = .022) were also superior in the CAS group at 6 months. Tests of attention, memory, and visual-spatial skills were similar between CAS and CEA patients at 6 weeks and 6 months. CONCLUSIONS Carotid revascularization improves memory and attention within the first 6 postoperative months. Compared with CEA, CAS produces improvements in cognitive processing speed, executive functioning, and motor function.

Utility of Retrievable Vena Cava Filters and Mechanical Thrombectomy in the Endovascular Management of Acute Deep Venous Thrombosis

OBJECTIVE Patients with occlusive or aneurysmal vascular disease are repeatedly exposed to intravascular (IV) contrast for diagnostic or therapeutic purposes. We sought to determine the long-term impact of cumulative iodinated IV contrast exposure (CIVCE) on renal function; the latter was defined by means of National Kidney Foundation (NKF) criteria. METHODS We performed a longitudinal study of consecutive patients without renal insufficiency at baseline (NFK stage I or II) who underwent interventions for arterial occlusive or aneurysmal disease. We collected detailed data on any IV iodinated contrast exposure (including diagnostic or therapeutic angiography, cardiac catheterization, IV pyelography, computed tomography with IV contrast, computed tomographic angiography); medication exposure throughout the observation period; comorbidities; and demographics. The primary end point was the development of renal failure (RF) (defined as NFK stage 4 or 5). Analysis was performed with the use of a shared frailty model with clustering at the patient level. RESULTS Patients (n = 1274) had a mean follow-up of 5.8 (range, 2.2-14) years. In the multivariate model with RF as the dependent variable and after adjusting for the statistically significant covariates of baseline renal function (hazard ratio [HR], 0.95; P < .001), diabetes (HR, 1.8; P = .007), use of an angiotensin-converting enzyme inhibitor (HR, 0.63; P = .03), use of antiplatelets (HR, 0.5; P = .01), cumulative number of open vascular operations performed (HR, 1.2; P = .001), and congestive heart failure (HR, 3.2; P < .001), CIVCE remained an independent predictor for RF development (HR, 1.1; P < .001). In the multivariate survival analysis model and after adjusting for the statistically significant covariates of perioperative myocardial infarction (HR, 3.9; P < .001), age at entry in the cohort (HR, 1.05; P = .035), total number of open operations (HR, 1.51; P < .001), and serum albumin (HR, 0.47; P < .001), CIVCE was an independent predictor of death (HR, 1.07; P < .001). CONCLUSIONS Cumulative IV contrast exposure is an independent predictor of RF and death in patients with occlusive and aneurysmal vascular disease.

Cost-effectiveness of Revascularization for Limb Preservation in Patients with Marginal Functional Status

Endovascular interventions of symptomatic deep venous thrombosis (DVT) using various therapeutic modalities, such as thrombolysis, mechanical thrombectomy, and inferior vena cava (IVC) filter placement, have received increased focus owing in part to advances in catheter-based interventional technologies. Although systemic anticoagulation remains the primary treatment modality in DVT, catheter-based interventions can provide rapid removal of large thrombus burden and possibly preserve venous valvular function in patients with symptomatic DVT. This article reviews current endovascular treatment strategies for acute DVT. Specifically, the utility of mechanical thrombectomy along with various temporary IVC filters in the setting of DVT is examined. Lastly, an illustrative case of acute DVT that was treated with endovascular intervention with IVC filter placement is presented.