Evaluation of wound healing after Angiosome-directed infrapopliteal endovascular angioplasty in critical limb ischemia

Abstract

A n angiosome is a three dimensional anatomic unit of tissue (consisting of skin, subcutaneous tissue, fascia, muscle, and bone) fed by a source artery and drained by specific veins. The foot and ankle arterial angiosome is represented as a topographic map that is divided into six territories; each territory is fed by three main arteries and their branches. Angiosome directed therapy refers to the establishment of flow to the topographic area of the foot where the wound is located. This can be achieved via direct flow, defined as inline, pulsatile flow through the affected angiosome source artery, or indirect flow represented by the strategy whereby flow to the wound area is provided by collaterals fed by an arterial conduit that is revascularized, as no direct flow is considered feasible. When the indirect flow approach is utilized, the recommendation is to open as many vessels as possible to increase the volume of blood to the foot (volume concept). A thorough stratification of each tissue defect including the extent, the depth, the percentage of surrounding viable tissue in the foot and specific associated risk factors (such as infection), other factors affecting wound healing (neuropathy, low albumin, renal insufficiency, metabolic or autoimmune disorders, thrombophilia, etc.) is equally required. Infrapopliteal interventions remain the Achilles heel of endovascular limb salvage efforts with pedal perfusion being the most important factor in wound healing. The role of angiosome directed, single or multiple vessel revascularisations in preserving the limb are areas of ongoing debate. While surgical revascularisation involves choosing the best outflow vessel, preferentially the vessel supplying the angiosome of interest, endovascular techniques have allowed treatment of more than one vessel at a single setting. Proponents of the multiple vessels approach suggest that this leads to higher tissue perfusion, and improved wound healing and limb salvage. Perfusion is maintained even after restenosis or occlusion of one vessel through the remaining patent vessel. This is a non-randomized prospective interventional cohort study, Patients presenting with critical limb ischemia due to infrapopliteal occlusive lesions, without significant superficial femoral or inflow arterial disease with good run in and run off tibial segments will undergo angioplasty for tibial vessels, then they will be categorized according to the anatomy of the wound and targeted vessel into ulcer angiosome direct arterial flow and ulcer angiosome indirect arterial flow. The protocol was approved by local ethics committee of Ain Shams University hospitals and all patients signed an informed consent form. The primary endpoint is complete wound healing, the secondary endpoints are limb salvage are amputation free survival rate. At the past any patient with peripheral vascular disease at the level of infrapopliteal vessels with intact popliteal pulse, will go for tibial angioplasty regardless the angiosome of the target vessels of the foot wound, in this study we aim to prove that angioplasty of the angiosome-target vessel of the foot wound supposed to improve the wound healing rate. The Technical success is considered as successful crossing of the lesion with balloon dilatation resulting in less than 30% residual diameter reduction as assessed by quantitative intra-procedural angiography. A successful revascularization was define as good distal collateralization to the foot circle and also the postprocedural ABI increased vs baseline measurements) is recorded in 40 cases, 27 cases (67.5 %) were managed to cross the lesion in the angiosomal tibial vessel directly supplying the foot ulcer (group A) while 13 cases (32.5 %) went for tibial angioplasty of the angiosomal tibial vessel indirectly supplying the foot ulcer (group B). Postoperative ABI in group (A) Mean ± SD 1.06 ± 0.13 ranging from 0.9 to 1.5, while in group (B) Mean ± SD 1.05 ± 0.14ranging from 0.9 to 1.4. Understanding the boundaries of the angiosome and the vascular connections among its source arteries provides the basis for logically rather than empirically designed incisions for tissue exposure or to plan reconstructions or amputations that ultimately preserve blood flow for a surgical wound to heal. The wound healing in the groups of the study, and by statistical calculation revealed that the mean duration of wound healing in group (A) ranged from 6 to 12 months with standard deviation 1.72 months, while the mean duration of wound healing in group (B) ranged from 1 to 2 months, with standard deviation 0.41 months. Also the data reveals the marked improvement of the foot wound healing rates group (A) compared to group (B).