Multi-center feasibility study of microwave radiometry thermometry for non-invasive differential diagnosis of arterial disease in diabetic patients with suspected critical limb ischemia.

AIMS: Diagnosis of vascular involvement in diabetic foot ulceration (DFU) remains challenging. We conducted a proof of concept study to investigate the feasibility of microwave radiometry (MWR) thermometry for non-invasive differential diagnosis of critical limb ischemia (CLI) in subjects with DFU. METHODS: This prospective, multi-center, study included 80 participants, divided into four groups (group N: normal control subjects; group DN: participants with diabetes and verified neuropathic ulcers without vascular involvement; group DC: participants with diabetes and CLI and group NDC: participants with CLI without diabetes). Vascular disease was confirmed with angiography. All patients underwent MWR (RTM-01-RES:University of Bolton, UK) to record mean tissue temperatures at various pre-determined foot sites. Comparisons of temperature measurements between study groups were performed using one-way ANOVA and Dunn tests. ROC analysis was performed to determine sensitivity, specificity and cut-off value of MWR for CLI diagnosis. RESULTS: Temperatures recorded in vicinity to the foot ulcers of participants with diabetes and CLI were similar to those with CLI without diabetes, but significantly lower than in subjects with neuropathic ulcers without vascular involvement and normal controls (group DC:29.30°C±1.89 vs. group NDC:29.18°C±1.78vs. group N:33.01°C±0.45 vs. group DN:33.39°C±1.37;P<.0001). According to ROC analysis, cut-off temperature value to diagnose CLI was <31.8°C (area under the curve: 0.984; 95% CI: 0.965-1.005;P<.001), with a sensitivity of 100.0% (95%CI: 90.26-100.0) and specificity of 88.37% (95% CI: 74.92-96.11). CONCLUSIONS: Tissue temperatures in vicinity to ulcers were significantly lower in participants with CLI, with or without diabetes, compared to non-ischemic controls. MWR could be used for differential diagnosis of arterial ischemia in subjects with DFU.

Long-Term Clinical Outcomes of Infrapopliteal Drug-Eluting Stent Placement for Critical Limb Ischemia in Diabetic Patients.

PURPOSE: To evaluate long-term clinical outcomes of infrapopliteal drug-eluting stent (DES) placement in insulin-dependent and non-insulin-dependent diabetic patients with critical limb ischemia (CLI). MATERIALS AND METHODS: A retrospective analysis was performed of all diabetic patients treated with infrapopliteal DES between January 2002 and September 2012. The study's primary outcome measures were patient survival and major amputation-free survival (AFS). Secondary outcome measures included technical success (defined as the creation of a straight line of blood flow to the foot arch with < 30%), identification of independent predictors of primary outcomes, infrapopliteal target limb repeat intervention-free survival, and procedure-related complications. RESULTS: In total, 214 patients with CLI (168 men [78.5%]; mean age, 70 y ± 9) in 311 limbs, 562 arteries, and 679 lesions were treated. According to Kaplan-Meier analysis, survival rates were 90.8%, 55.5%, and 36.2%, and AFS rates were 94.9%, 90.4%, and 90.4%, respectively, at 1, 5, and 10 years. Target limb repeat intervention-free survival rates were 79.7%, 55.2%, and 49.7%, respectively, at 1, 5, and 10 years. The overall technical success rate was 97.7%. Cox multivariate analysis demonstrated that procedural failure was the only independent predictor of decreased AFS (hazard ratio [HR], 61.3; 95% confidence interval [CI], 13.8-271.9), and statin use was associated with increased survival (HR, 0.55; 95% CI, 0.31-0.98). Coronary disease (HR, 1.9; 95% CI, 1.01-3.54), dialysis (HR, 2.2; 95% CI, 1.21-4.06), and duration of diabetes (HR, 1.5; 95% CI, 1.02-2.34) were identified as independent predictors of decreased survival. Major complications occurred in four of 479 procedures (0.8%). CONCLUSIONS: Infrapopliteal DES placement for the management of CLI in diabetic patients resulted in a 55.5% 5-year survival rate, with a 90.4% AFS at 5 and 10 years and a 50.3% repeat intervention rate at 10 years. Technical failure was associated with reduced AFS, and statin intake was associated with increased survival.

Endovenous ablation of incompetent truncal veins and their perforators with a new radiofrequency system. Mid-term outcomes.

This is a prospective trial investigating endovenous radiofrequency ablation with the EVRF system for the treatment of symptomatic varicose veins. Primary endpoints include one-year anatomical and clinical success and procedure-related complications. Secondary endpoints include adjunctive procedures and recanalization rates, periprocedural pain assessment, and time return to normal activities. In 60 patients with 74 limbs, 58 great saphenous vein, 11 small saphenous vein, 2 anterior accessory saphenous vein, and 3 perforators were ablated. Additional ablations for further improvement were necessary in 28.4%. Clinical success was 94.6%. Anatomical success was 96.0% at one month and 89.2% at one year. Primary ablation success was 77%. Revascularization occurred in 12.1%. Clinically driven repeat ablation rate was 4.0%. Perforator ablation due to segmental revascularization was performed in 5.4%. Complications included one puncture-site infection, three scars, two cases of transient paresthesia, and one skin pigmentation. Periprocedural mean pain score was 2.4 ± 2.6. In 27.0% cases, the patients used analgesics and mean time return was 1.2 ± 0.5 days. The EVRF system yields satisfactory clinical and anatomical midterm outcomes with very low complication rates.

Distal macro- and microembolization during subintimal recanalization of femoropopliteal chronic total occlusions.

PURPOSE: To investigate the phenomenon of distal embolization during subintimal angioplasty with or without stenting of femoropopliteal chronic total occlusions (CTOs). METHODS: This prospective study included 40 consecutive patients (35 men; mean age 65.4±9.3 years) who underwent subintimal angioplasty alone (n=14) or with stenting (n=26) of CTOs in the femoropopliteal segment. A Spider protection filter was used to capture any possible macro- or microemboli generated during balloon inflation/stenting. Arterial outflow was angiographically checked during each consecutive procedural step. All filters were examined on site for macroscopic material, while the first 20 filters underwent further histopathological qualitative and semiquantitative analysis using a 0+ to 3+ score. RESULTS: There was no angiographically or clinically evident distal embolization. Macroscopic particulate debris was not detected in any filter. Histopathology confirmed the absence of macroemboli but revealed microembolic material (diameter <100 µm) in all filters (20/20). The mean number of particles detected was 9.4±4.5 (range 5-17). Histopathological findings included fibrin conglomerates (20/20), trapped erythrocytes (19/20), inflammatory cells (16/20), calcification minerals (6/20), extracellular matrix (6/20), cholesterol clefts (6/20), and endothelial cells (6/20). Captured material was classified as fresh and old thrombus in 7/20 and 4/20 cases, respectively. Semiquantitative analysis demonstrated that the collected microparticles consisted primarily of fibrin conglomerates (median score 2+), trapped erythrocytes (median score 1+), and inflammatory cells (median score 1+). CONCLUSION: Macroscopically evident emboli were not detected following subintimal angioplasty or stenting of femoropopliteal CTOs. Microscopic debris was present in all filters. The clinical significance of the phenomenon remains to be determined.

Feasibility of endovascular recanalization of occluded infrapopliteal drug-eluting stents.

PURPOSE: To investigate the safety and feasibility of percutaneous endovascular recanalization of late total occlusions of infrapopliteal drug-eluting stents (DES). METHODS: A retrospective study investigated all 408 infrapopliteal stent procedures performed in 367 patients between January 2007 and October 2013 to identify those who underwent percutaneous reintervention for symptomatic infrapopliteal balloon-expandable DES occlusion. The search identified 49 patients with at least one infrapopliteal DES occlusion in 61 (14.9%) of 408 limbs. Seven (14.3%) patients were excluded from the analysis owing to asymptomatic status (n=6) and acute thrombotic occlusion (n=1), leaving 42 patients who underwent endovascular revascularization of occluded stents in 54 limbs. The study's primary outcomes were technical success and complication rates of endovascular recanalization, while secondary outcomes included limb salvage and the identification of factors influencing primary results. RESULTS: Technical success was 90.7% (49/54 procedures). Technical failure was seen only in cases of stent collapse and overlapping native popliteal artery-infrapopliteal stent occlusion. According to Kaplan-Meier analysis, survival was 89.6%, 81.1%, and 73.5% at 1, 2, and 3 years, respectively, while limb salvage rates were 86.1%, 79.3%, and 72.7% at the same time points. There was 1 (1.8%) case of distal embolization. No factors influencing outcomes could be identified. CONCLUSION: Percutaneous recanalization of infrapopliteal stent total occlusions is safe and feasible. Technical failure was noted in cases of stent deformation occurring at the pedal artery and in overlapping native popliteal artery-infrapopliteal stent occlusion.