The Role of the Angiosome Concept in the Treatment of below the knee Critical Limb Ischemia

Background: Critical limb ischemia (CLI) presented as a foot ulcer with or without gangrene requires the quick re-establishment of arterial blood supply. The recently introduced angiosome concept has offered a new perspective on the treatment of CLI. The idea of angiosome-targeted (direct) revascularization⎯the restoration of blood flow directly to the angiosome affected by an ischemic wound appeared among vascular surgeons. The concept has rised interest among vascular specialists as several studies supported the hypothesis of a better clinical outcome after direct revascularization. Despite the promising results, the feasibility of the concept in endovascular treatment has not been addressed, nor has a comparison of revascularization methods, endovascular versus open surgical, been investigated. Furthermore, the methodology is not consistent, and the definition of direct revascularization is unclear, especially if the wound spreads over several angiosomes. Therefore, clinical value of the hypothesis is yet to determined. Aim of the study: The aim of this study was to investigate the importance of the angiosome concept in the treatment of CLI with tissue loss (Rutherford 5,6). The main goals were to evaluate the feasibility of the concept in endovascular procedures; to compare the clinical outcomes of direct and indirect revascularization; and to obtain a consensus concerning the angiosome-targeted approach. Patients and methods: The study comprises patients referred for infrapopliteal revascularization, endovascular or open surgical, between 2008 and 2013. We analyzed patient s records retrospectively, focusing on wound location, the feasibility of infrapopliteal direct revascularization, and differences in clinical outcome, with the main interest in wound healing and leg salvage. We also compared the clinical outcome of two existing definitions of angiosome-targeted revascularizations as they differ in revascularization approach of leasions located in forefoot and the heel. Definition A accepts into the direct group if any of the affected angiosomes is revascularized, while Definition B accepts only revascularization of posterior tibal artery. Main Results: For the feasibility of the angiosome concept in endovascular infrapopliteal revascularization, the wound was isolated to a single angiosome in only 24% of the cases, and 33% of the patients had only one infrapopliteal artery suitable for revascularization. The success rate of direct revascularization, however, was 75.9%. When comparing direct and indirect revascularization, the propensity score analysis yielded significantly better leg salvage (p=0.019) and a trend towards improved wound healing (p=0.058) for the direct approach, and when adjusted for revascularization method, direct bypass was associated with a significantly higher wound-healing rate than endovascular revascularization (HR 1.295, 95%CI 1.005 1.668). Among diabetic patients, the findings showed that direct bypass yielded significantly better wound healing than indirect PTA (p=0.001, HR 2.83, 95%CI 1.35 3.04), and, furthermore, indirect PTA was associated with the poorest leg salvage rate. The analysis of the two different angiosome-targeted approaches revealed a significantly better feasibility of the conventional method (definition A) compared to definition B (p less than 0.05). Furthermore, the prognostic ability for better clinical outcome using definition A was confirmed by both the Cox proportional hazard analysis (p= 0.044 for wound healing, p= 0.047 for leg salvage) and the propensity score analysis (p= 0.037 for wound healing, p= 0.044 for leg salvage). Conclusion: The tissue lesion affects several angiosomes in the majority of the cases, and a consensus on the accurate definition of angiosome-targeted revascularization needs to be achieved to standardize the methodology of arterial selection. Despite the inconsistent methodology in the literature, our findings seem to suggest that observing the angiosome concept in the decision-making yields better clinical outcomes, especially in endovascular therapy. In bypass surgery, however, the concept seems to be of less value, and the artery with the best runoff should be selected as the outflow artery.non

The Feasibility of Angiosome-Targeted Endovascular Treatment in Patients with Critical Limb Ischaemia and Foot Ulcer

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The Prognostic Significance of Different Definitions for Angiosome-Targeted Lower Limb Revascularization

Background: The definition of angiosome-targeted revascularization is confusing, especially when a tissue lesion affects several angiosomes. Two different definitions of direct revascularization exist in the literature. The study aim was (1) to compare the 2 definitions of direct revascularization in patients with foot lesions involving more than one angiosome and (2) to evaluate which definition better predicts clinical outcome. Methods: This study cohort comprises 658 patients with Rutherford 5-6 foot lesions who underwent infrapopliteal endovascular or surgical revascularization between January 2010 and July 2013. We compared the 2 angiosome-targeted definitions using multivariate analysis; the impact of each angiosome-targeted definition was adjusted for a propensity score obtained by means of nonparsimonious logistic regression. Results: Direct revascularization according to definition A was performed in 367 cases (55.8%) versus 198 cases (30.1%) with definition B. The propensity-score-adjusted analysis showed that definition A of direct revascularization was associated with significantly better wound healing (P <0.044, hazard ratio [HR] 1.291) and lower amputation rates (P <0.047, HR 0.706), whereas definition B was associated only with significantly better wound healing (P <0.029, HR 1.321). The prognostic ability of direct revascularization according to definition A was confirmed in a Cox proportional hazard analysis. Conclusions: Definition A of direct revascularization was associated with a significantly higher wound healing and leg salvage rate than indirect revascularization in both series. Therefore, it seems that, if the wound spreads over several angiosomes in the forefoot or heel, any angiosome involved in the wound can be targeted.Peer reviewe

Quality Control of the Foot Revascularization Using Indocyanine Green Fluorescence Imaging

Objectives Critical limb ischemia (CLI) is a clinical diagnosis, confirmed by objective tests, usually ankle-brachial index (ABI), toe pressure (TP) and TcPO2. Furthermore, the anatomical lesions in patients affected by CLI were visualized by ultrasound, angiography, CTA, or MRA. Indocyanine green fluorescence imaging (ICG-FI) is a diagnostic modality for assessing foot perfusion. We aimed to study the usefulness of ICG-FI in the quality control of revascularization. Materials and methods One hundred and four CLI limbs in 101 patients were studied with ICG-FI using SPY Elite before and after open or endovascular revascularization. ABI and TP were also measured. After ICG-FI, assessment of circulation was done using time-intensity curve derived from the two regions of interest the one being in the plantar side of the foot and the other in the dorsal side of the foot. Three parameters were derived from the curves: maximum intensity (the absolute value of the maximum intensity); intensity rate (the value from the time-intensity curve describing the increase in maximum intensity/s) and SPY10 (the intensity achieved during the first 10 s after the foot starts to gain intensity). Results Sixty-two limbs presented category 3 of Rutherford classification, 12 limbs category 4, and 30 limbs category 5. Ninety-five technically successful procedures were achieved, 63 (66.3%) endovascular and 32 (33.7%) surgical revascularizations. In 9 (9.5%) patients, an in-line flow from the aorta to the foot was not achieved due to a failure to recanalize the occlusion (n = 7) or due to distal embolization (n = 2). ABI was not reliable in 58 patients (57.4%) mostly due to pseudohypertension and TPs in 49 (48.5%) patients mostly due to previous minor amputations. ICG-FI was successful in all patients. The mean intensity values before and after the procedure in patients who underwent successful revascularization were 81 +/- 47 units and 120 +/- 5 units of intensity (p <001) and intensity rates 4.2 +/- 4 and 8.0 +/- 6.2 units/s (p =.001), respectively. In the PTA patients in whom the revascularization was unsuccessful, no changes were seen in the hemodynamic parameters. In 6 (8.8%) patients who underwent technically successful revascularization, the SPY values were worse after the revascularization than at the baseline. Conclusions ICG-FI with SPY Elite provides reliable information on the increase in perfusion after revascularization, in addition to implicating possible failure if there is no improvement in the ICG-FI variables. Unlike ABI and TP, it can be performed in all patients. It gives valuable information to complement traditional assessment methods.Peer reviewe

Competing Risk Analysis of the Impact of Pedal Arch Status and Angiosome-Targeted Revascularization in Chronic Limb-Threatening Ischemia

Introduction In the context of chronic limb threatening ischemia (CLTI), the prognostic impact of angiosome-targeted revascularization and of the status of the pedal arch are debated. Materials and method This series includes 580 patients who underwent endovascular (n=407) and surgical revascularization (n=173) of the infrapopliteal arteries for CLTI associated with foot ulcer or gangrene. The risk of major amputation after infrapopliteal revascularization was assessed by a competing risk approach. A subanalysis was made separately for patients who underwent endovascular or open surgical revascualrization. Results At 2 years, survival was 65.1% and leg salvage was 76.1%. Multivariable competing risk analysis showed that C-reactive protein≥ 10 mg/dL, diabetes, rheumatoid arthritis, increased number of affected angiosomes and the incomplete or total absence of pedal arch compared to complete pedal arch were independent predictors of major amputation after infrapopliteal revascularization. Multivariable analysis showed increasing risk estimates of major amputation in patients with incomplete (SHR 2.131, 95%CI 1.282-3.543) and no visualized pedal arch (SHR 3.022, 95%CI 1.553-5.883) compared to complete pedal arch. Pedal arch was important even if angiosome-targeted revascularization was achieved: Angiosome-directed revascularization in presence of complete pedal arch had a lower risk of major amputation (adjusted SHR 0.463, 95%CI 0.240-0.894) compared to angiosome-directed revascularization without complete pedal arch. In the subanalysis, among patients who underwent endovascular revascularization, complete pedal arch (SHR 0.509, 95%CI 0.286-0.905) and angiosome-targeted revascularization (SHR 0.613, 95%CI 0.394-0.956) were associated with a lower risk of major amputation. Conclusions Competing risk analysis showed that a patent pedal arch had significant impact on leg salvage and that the subset of patients undergoing endovascular procedure may most benefit of an angiosome-targeted revascularization.Peer reviewe

Angiosome Targeted PTA is More Important in Endovascular Revascularisation than in Surgical Revascularisation : Analysis of 545 Patients with Ischaemic Tissue Lesions

Introduction: This study aimed to evaluate the impact of angiosome targeted (direct) revascularisation according to revascularisation method in patients with diabetes. Materials and methods: This retrospective study cohort comprised 545 diabetic patients with critical limb ischaemia and tissue loss (Rutherford 5, 6). All patients underwent infrapopliteal endovascular (PTA) or open surgical revascularisation between January 2008 and December 2013. Differences in the outcome after direct revascularisation, bypass surgery, and PTA were investigated by means of Cox proportional hazards analysis. The endpoints were wound healing, leg salvage, and amputation free survival. Results: Overall, 60.3% of the ischaemic wounds healed during 1 year of follow-up. The highest wound healing rate was achieved after direct bypass (77%) and the worst after indirect PTA (52%). The Cox proportional hazards analysis showed that the number of affected angiosomes = 10 mg/dL (HR 2.05, 95% CI 1.45-2.90), atrial fibrillation (HR 1.54, 95% CI 1.05-2.26), and number of affected angiosomes >3 (HR 1.75, 95% CI 1.24-2.46) were significantly associated with poor leg salvage. Direct PTA was associated with a lower rate of major amputation compared with indirect PTA (HR 0.57 95% CI 0.37-0.89). Conclusion: In diabetics, indirect endovascular revascularisation leads to significantly worse wound healing and leg salvage rates compared with direct revascularisation. Therefore, endovascular procedures should be targeted according to the angiosome concept. In bypass surgery, however, the concept is of less value and the artery with the best runoff should be selected as the outflow artery. (C) 2017 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.Peer reviewe