Angiosome Concept Research Articles

Comparative Outcomes of Targeted Versus Nontargeted Angiosome Revascularization for Diabetic Foot Wounds Impact of Target Arterial Path on Wound Healing

Diabetes is strongly correlated with the development of critical limb ischemia (CLI), with a predilection for below-the-knee and below-the-ankle patterns of arterial disease. The angiosome concept, described as a potential framework for targeted revascularization in CLI, has generated divergent opinions over the last decades. This study aims to evaluate the implication of angiosome targeted revascularization in wound healing in diabetic patients. This is a single-center retrospective study including diabetic patients with ischemic ulcers admitted for invasive vascular study and revascularization between January and December 2019. The primary outcome was to evaluate the impact of angiosome-targeted revascularization in wound healing. Limb-based patency and amputation-free survival according to GLASS stage and revascularization procedures were considered secondary outcomes. Data from 117 limbs of 114 diabetic patients with neuroischemic diabetic foot were evaluated. There was no significant difference between targeted and non-targeted angiosome-revascularization in wound healing at 12 months. However, angiosome targeted revascularization was associated with shorter healing times. The severity of the infection was the only variable with an impact on healing time. Endovascular surgery did not show inferior patency to open surgery, even in patients with more complex arterial disease (GLASS III). Although angiosome-guided revascularization did not demonstrate significantly higher healing rates at 12 months, there appears to be a trend towards faster healing.

Application of flow-through flaps for replantation after traumatic limb amputation according to the angiosome concept.

This study was performed to explore the treatment of the injury caused by traumatic limb amputation. From October 2002 to October 2021, 30 cases were enrolled in the present study. The reasons for injury were as follows: 8 cases with single hydraulic column crush injury, 12 cases with gear and wire rope stranding, 6 cases with belt avulsion injury, and 4 cases with carbon block smash injury. The present study application of a free or small saphenous vein bypass to reconstruct the injured artery and vein according to the concept of the angiosome model. The defective vessels were bridged with the axial vessels of a flow-through flap, such as a medial calf flap or anterolateral femoral flap, to construct an additional blood supply and drainage vein for the severed limb. The clinical data of 30 cases with traumatic limb amputation of the lower leg and ankle were retrospectively analyzed. In all 30 cases of traumatic limb amputation, the replantation via the adoption of a flow-through flap was successful, and 85.6% of the patients remained in good postoperative condition. There were no symptoms of ischemia in the marginal segment after blood supply reconstruction of the transected limb by axial vascular bridging within the flap. Via the adoption of microsurgical techniques, the blood supply to the transected limb can be reconstructed by bridging the defective vessels with the adoption of the axial vessels of the flow-through flap is a feasible and advanced treatment option.

Challenging the angiosome concept: Delineating peripheral arterial disease patterns in diabetic foot ulcers.

The angiosome concept has significantly impacted diabetic foot ulcer management by highlighting the vascular anatomy's role in wound healing. However, its clinical applicability and validity remain debated due to complexities in foot blood supply and ulcer location determination. A cross-sectional study was conducted on 84 individuals with diabetic foot ulcers undergoing lower limb angiography. Demographics, ulcer characteristics, and angiographic data were collected and analyzed using descriptive statistics and relevant tests. Digital subtraction angiography assessed 89 limbs with diabetic foot ulcers; males comprised 54.8%, primarily type 2 diabetes (96.4%), averaging 64.36 ± 10.09 years. Of 129 angiosomes, angiosome 2 (40.3%) had the highest ulcer incidence. Posterior tibial artery (PTA) involvement was predominant (72.9%), while external iliac artery (EIA) and profunda femoris artery (PFA) were least affected (2.4% each). Posterior tibial artery showed 46.5% complete occlusion. Angiosome 2 correlated notably with anterior tibial artery (ATA), peroneal artery (CPA), and PTA, but categorizing angiosomes by supply patterns showed no significant artery correlation (p > .05). The research indicates inconsistent support for below-the-knee artery involvement correlating with foot ulcer locations in angiosomes. While aiding vascular comprehension, the angiosome concept may not fully elucidate lower limb vascular complexities and ulcer genesis. Factors like collateral circulation should be noticed to understanding ulcer localization and severity, extending beyond angiosomal arterial supply.

Angiosome-Targeted Infrapopliteal Angioplasty: Impact on Clinical Outcomes—An Observational Study

Background: Revascularization based on the angiosome concept (AC) is a controversial subject because there is currently no clear evidence of its efficacy, due to the heterogeneity of patients (multiple and diverse risk factors and comorbidities, multiple variations in the affected angiosomes). Choke vessels change the paradigm of the AC, and the presence or absence of the plantar arch directly affects the course of targeted revascularization. The aim of this study was to evaluate the effect of revascularization based on the AC in diabetic patients with chronic limb-threatening ischemia (CLTI). Methods: This retrospective analysis included 51 patients (40 men, 11 women), with a mean age of 69 years (66–72) and a total of 51 limbs, who presented with Rutherford 5–6 CLTI, before and after having undergone a drug-coated balloon angioplasty (8 patients) or plain balloon angioplasty (43). Between November 2018 and November 2019, all patients underwent below-the-knee balloon angioplasties and were followed up for an average of 12 months. The alteration of microcirculation was compared between directly and indirectly revascularized angiosomes. The study assessed clinical findings and patient outcomes, with follow-up investigations, comparing wound healing rates between the different revascularization methods. Patient records and periprocedural leg digital subtraction angiographies (DSA) were analyzed. Differences in outcomes after direct revascularization and indirect percutaneous transluminal angioplasty (PTa) were examined using Cox proportional hazards analysis, with the following endpoints: ulcer healing, limb salvage, and also amputation-free survival. Results: Direct blood flow to the angiosome supplying the ulcer area was achieved in 38 legs, in contrast to 13 legs with indirect revascularization. Among the cases, there were 39 lesions in the anterior tibial artery (ATA), 42 lesions in the posterior tibial artery (PTA), and 8 lesions in the peroneal artery (PA). According to a Cox proportional hazards analysis, having fewer than three (<3) affected angiosomes (HR 0.49, 95% CI 0.19–1.25, p = 0.136) was associated with improved wound healing. Conversely, wound healing outcomes were least favorable after indirect angioplasty (p = 0.206). When adjusting the Cox proportional hazard analysis for the number of affected angiosomes, it was found that direct drug-coated angioplasty resulted in the most favorable wound healing (p = 0.091). At the 1-year follow-up, the major amputation rate was 17.7%, and, according to a Cox proportional hazards analysis, atrial fibrillation (HR 0.85, 95% CI 0.42–1.69, p = 0.637), hemodialysis (HR 1.26, 95% CI 0.39–4.04, p = 0.699), and number of affected angiosomes > 3 (HR 0.94, 95% CI 0.63–1.39, p = 0.748) were significantly associated with poor leg salvage. Additionally, direct endovascular revascularization was associated with a lower rate of major amputation compared to indirect angioplasty (HR 1.09, 95% CI 0.34–3.50, p = 0.884). Conclusions: Observing the angiosomes concept in decision-making appears to result in improved rates of arterial ulcer healing and leg salvage, particularly in targeted drug-coated balloon angioplasty for diabetic critical limb ischemia, where multiple angiosomes are typically affected.

The Utility of Advanced Lower-Extremity Duplex Using Pedal Acceleration Time in the Management of the Threatened Diabetic Foot.

Patients with diabetes and diffuse infrageniculate arterial disease who present with chronic limb-threatening ischemia require an exact anatomical plan for revascularization. Advanced pedal duplex can be used to define possible routes for revascularization. In addition, pedal acceleration time (PAT) can predict the success or failure of both medical and surgical interventions. A retrospective review of patients who were referred to our group for unilateral limb-threatening ischemia with isolated infrageniculate disease was conducted. Pedal duplex and PAT at the base of the wound was performed before and 1 week after intervention. The primary endpoint was limb salvage at 1 year. Revascularization was defined as direct or indirect based on the angiosome concept. Fifty-four patients meeting inclusion criteria presented over a 5-year period (toe wound, n = 42; heel wound, n = 8; both, n = 4). At 1 year, 10 (18.5%) had required below-knee amputation, whereas the remainder had healed/improved. Limb salvage was predicted by absence of ongoing smoking, absence of dialysis, and postprocedural PAT (class I/II). Limb salvage did not correlate with direct versus indirect revascularization. Advanced lower-extremity duplex in conjunction with determining PAT at the area of concern is a useful technique for mapping the vasculature and identifying targets for revascularization in patients with diffuse infrageniculate disease. Target artery revascularization to the wound bed resulting in a PAT less than 180 msec is predictive of limb salvage, regardless of whether perfusion is direct or indirect.

Successful Revascularization, Angiosome Concept, and Multivessel Revascularization: Effects on Wound Healing: An Asian Perspective.

Endovascular treatment for revascularization in patients with chronic limb-threatening ischemia (CLTI), which is commonly found in patients with diabetes mellitus demonstrates a variable result of vessel patency, wound healing rate, and limb salvage rate. The angiosome concept has been adopted to determine the best target arterial path (TAP) for revascularization for wound healing in CLTI patients. Recent publications demonstrated the benefit of angiosome-targeted revascularization to guide the endovascular treatment in patients CLTI. The best TAP under angiosome concept by direct revascularization with at least 2 of 3 below-the-knee arteries runoff to restore in-line pulsatile blood flow to the ischemic tissue shows the best patency and high rate of wound healing. However, the clinical evidence and application of the angiosome concept in daily practice are difficult and not well established. The vascular territories, collateral vessel, wound area, and locations which associated with angiosome are varied. This article review aims to summarize the concept of angiosome-targeted revascularization and multivessel revascularization for application to the real-world practice under the evidence-based data.

Analyses of transcutaneous oxygen pressure values stratified for foot angiosomes to predict diabetic foot ulcer healing

AimsPrevious research suggested that diabetic foot ulcer (DFU) location could affect transcutaneous oxygen pressure (TcPO2) values following the angiosome concept. Up to our knowledge no studies have yet analyzed if the location of a diabetic foot ulcer can be a confounding factor that modifies TcPO2 values. The primary aim of this study was to compare the potential healing prognosis of TcPO2 differentiated for diabetic foot ulcers in different angiosome locations. Methodsa 2-years observational cohort prospective study was performed in 81 patients with diabetic foot ulcers. Transcutaneous oxygen pressure measurements were performed at baseline by placing the electrode on two different angiosomes: dorsal zone of the foot (dorsalis pedis angiosome) and between the navicular bone and the tibial malleolus (posterior tibial angiosome). The main outcome was establishing the effectiveness of TcPO2 measurements (dorsalis pedis angiosome and posterior tibial angiosome) for predicting DFU healing. ResultsTranscutaneous oxygen pressure probe placed in the dorsum of the foot (dorsalis pedis angiosome) yielded a sensitivity (S) of 95 % and specificity (SP) of 73 %, and an area under the curve (AUC) of 0.902 (p < 0.001 [0.84–0.96]) for ulcers located in the forefoot and toes; while TcPO2 placed in the posterior tibial angiosome yielded an S of 100 % and SP of 85 % and an AUC of 0.894 (p < 0.001 [0-822-0.966]) for DFU located in the midfoot and heel. ConclusionThis study suggests that angiosome-guided TcPO2 contributes to a prognosis of successful foot ulcer healing.

The Effects of Angiosome Morphology on Choke Vessels and Flap Necrosis in a Rat Multiterritory Perforator Flap.

Although the angiosome concept has been proposed for a long time, very few studies have been done on its morphology. Our study investigated the effects of angiosome morphology on choke vessels and flap necrosis in a rat multiterritory perforator flap. Seventy-two male Sprague-Dawley rats were randomly divided into 3 groups (n = 24/group). The flap contained the right iliolumbar, posterior intercostal, and thoracodorsal angiosomes (TDAVs), termed angiosomes I, II, and III, respectively. Only the posterior intercostal artery and iliolumbar vein were preserved in group 1, whereas only the posterior intercostal artery and vein were preserved in group 2, and only the posterior intercostal artery and thoracodorsal vein were preserved in group 3. Distances from angiosome II to angiosome I (II-I), angiosome II to angiosome III (II-III), angiosome I to the caudal side of the flap (I-caudal), and angiosome III to the cranial side of the flap (III-cranial) were measured. Arteriography, flap necrosis, average microvascular density, and vascular endothelial growth factor expression were evaluated. The II-I distance was significantly greater than that of II-III (3.853 ± 0.488 versus 3.274 ± 0.433 cm, P = 0.012), whereas the distance of I-caudal resembled that of III-cranial (1.062 ± 0.237 versus 0.979 ± 0.236 cm, P = 0.442). The iliolumbar and posterior intercostal angiosomes were multidirectional, whereas the TDAV was craniocaudal and unidirectional. Seven days after the operation, the choke arteries had transformed into true anastomotic arteries. Flap necrosis was lowest in group 3, followed by group 2, and highest in group 1 (10.5% ± 2.4% versus 18.3% ± 3.5% versus 25.5% ± 4.6%, P < 0.01), whereas group 3 showed the highest microvascular density and vascular endothelial growth factor expression, in contrast to groups 2 and 1, with the lowest. The choke vessel adjacent to the craniocaudal and unidirectional TDAV significantly blocked venous return. Increasing venous return may reduce the necrosis.

Evaluation of the Angiosome Concept Using Near-Infrared Fluorescence Imaging with Indocyanine Green

The angiosome concept is defined as the anatomical territory of a source artery within all tissue layers. When applying this theory in vascular surgery, direct revascularization (DR) is preferred to achieve increased blood flow toward the targeted angiosome of the foot in patients with lower extremity arterial disease (LEAD). This study evaluates the applicability of the angiosome concept using quantified near-infrared (NIR) fluorescence imaging with indocyanine green (ICG). This study included patients undergoing an endovascular- or surgical revascularization of the leg between January 2019 and December 2021. Preinterventional and postinterventional ICG NIR fluorescence imaging was performed. Three angiosomes on the dorsum of the foot were determined: the posterior tibial artery (hallux), the anterior tibial artery (dorsum of the foot) and the combined angiosome (second to fifth digit). The angiosomes were classified from the electronic patient records and the degree of collateralization was classified based on preprocedural computed tomography angiography and/or X-ray angiography. Fluorescence intensity was quantified in all angiosomes. A subgroup analysis based on endovascular or surgical revascularized angiosomes, and within critical limb threatening ischemia (CLTI) patients was performed. ICG NIR fluorescence measurements were obtained in 52 patients (54 limbs) including a total of 157 angiosomes (121 DR and 36 indirect revascularizations [IR]). A significant improvement of all perfusion parameters in both the directly and indirectly revascularized angiosomes was found (P-values between <0.001-0.007). Within the indirectly revascularized angiosomes, 90.6% of the scored collaterals were classified as significant. When comparing the percentual change in perfusion parameters between the directly and indirectly revascularized angiosomes, no significant difference was seen in all perfusion parameters (P-values between 0.253 and 0.881). Similar results were shown in the CLTI patients subgroup analysis, displaying a significant improvement of perfusion parameters in both the direct and indirect angiosome groups (P-values between <0.001 and 0.007), and no significant difference when comparing the percentual parameter improvement between both angiosome groups (P-values between 0.134 and 0.359). Furthermore, no significant differences were observed when comparing percentual changes of perfusion parameters in directly and indirectly revascularized angiosomes for both endovascular and surgical interventions (P-values between 0.053 and 0.899). This study proves that both DR and IR of an angiosome leads to an improvement of perfusion. This suggests that interventional strategies should not only focus on creating in-line flow to the supplying angiosome. One can argue that the angiosome concept is not applicable in patients with LEAD.

Assessment of chronic limb threatening ischemia using thermal imaging

ObjectivesCurrent chronic limb threatening ischemia (CLTI) diagnostics require expensive equipment, using ionizing radiation or contrast agents, or summative surrogate methods lacking in spatial information. Our aim is to develop and improve contactless, non-ionizing and cost-effective diagnostic methods for CLTI assessment with high spatial accuracy by utilizing dynamic thermal imaging and the angiosome concept. ApproachDynamic thermal imaging test protocol was suggested and implemented with a number of computational parameters. Pilot data was measured from 3 healthy young subjects, 4 peripheral artery disease (PAD) patients and 4 CLTI patients. The protocol consists of clinical reference measurements, including ankle- and toe-brachial indices (ABI, TBI), and a modified patient bed for hydrostatic and thermal modulation tests. The data was analyzed using bivariate correlation. ResultsThe thermal recovery time constant was on average higher for the PAD (88%) and CLTI (83%) groups with respect to the healthy young subjects. The contralateral symmetry was high for the healthy young group and low for the CLTI group. The recovery time constants showed high negative correlation to TBI (ρ = -0.73) and ABI (ρ = -0.60). The relation of these clinical parameters to the hydrostatic response and absolute temperatures (|ρ|<0.3) remained unclear. ConclusionThe lack of correlation for absolute temperatures or their contralateral differences with the clinical status, ABI and TBI disputes their use in CLTI diagnostics. Thermal modulation tests tend to augment the signs of thermoregulation deficiencies and accordingly high correlations were found with all reference metrics. The method is promising for establishing the connection between impaired perfusion and thermography. The hydrostatic modulation test requires more research with stricter test conditions.

Evolution of Anatomical Studies on the Arterial, Venous, and Lymphatic System in Plastic Surgery.

Anatomies of the vascular and lymphatic systems have been vital research topics in reconstructive surgery. Harvey was a pioneer who provided the earliest descriptions of the cutaneous vasculature in the 17th century. The concept of vascular territories of the skin was first described by Manchot. The radiographic injection method in cadavers was developed by Salman, who defined more than 80 vascular territories. The arterial system has been thoroughly investigated with the development of regional and free flaps. The concept of axial and random pattern flaps was introduced by McGregor and Morgan. Manchot's vascular territories were refined by Taylor and Palmer as the angiosome concept. Detailed information about the venous circulation is essential for reconstructive surgeries. The concept of intrinsic and extrinsic venocutaneous vascular systems was introduced by Nakajima and led to the development of the venoadipofascial flap. The importance of venous augmentation in flap survival was emphasized by Chang. The lymphatic system was discovered much later than the arterial and venous systems. Aselli was credited for discovering the lacteal vessels in the 17th century; mercury was popularly used as a contrast agent to distinguish lymphatic vessels for the next three centuries. A radiographic method in cadavers was developed by Suami. Lymphatic imaging devices are constantly upgrading, and photoacoustic imaging was recently introduced for three-dimensional visualization of architecture of superficial layers of the lymphatic and venous systems.

Identification of Unequal Flow-Carrying Capabilities of Choke Vessels in Rat Abdominal Flaps.

Although the angiosome concept is a well-accepted theory, unexpected necrosis suggests that other factors can influence the flap survival. Our study uses the rat model to explore the flow capacity of the choke vessels across 2 angiosomes. The medioventral line of Sprague-Dawley rats' abdominal flap was equally divided into 4 sections, which were preserved in 7 different groups (n = 6/group): A, no dissection; B to D, preserve the inferior 1/4, 2/4, and 3/4 sections; E to G, preserve the superior 1/4, 2/4, and 3/4 sections. The ratio (%) of the survival area of the distal/proximal territory was calculated. Indocyanine green, lead-oxide gel imaging, hematoxylin and eosin, and CD31 histology tests were performed. Compared with 96.0 ± 1.4% flap survival in group A, groups B, C, and D had distal territory flap loss (34.8% ± 4.1%, 65.0% ± 3.7%, and 94.3% ± 3.1% respectively). Group E lost the majority of the distal territory (3.5% ± 2.4%), whereas groups F and G (15.5% ± 3.8% and 79.2% ± 3.3%, respectively) had larger flap survival. Except for groups A and D, each of the other 2 groups showed statistically significant results ( P < 0.001). Indocyanine green indicated no blood flow at the superior 1/4 part. Lead-oxide gel and histology showed that the choke vessels residing along the medioventral line had no significant difference. Choke vessels do not carry blood flow equally. Two categories of choke vessels-"resting" and "active"-are proposed. The "active" form has variable flow carrying capabilities when the flap is harvested in different designs.

Tissue Perfusion Changes after Direct and Indirect Angiosome Revascularization in Critical Limb Ischemia

Background. Blood flow restore in critical limb ischemia according to angiosomes is becoming very popular. This method allows to restore blood flow precisely to the artery supplying the ischemic zone, based on the angiosome concept. However, angiosome revascularization is not a gold standard because of the lack of evidence supporting this approach. The aim of this study was to compare tissue oxygenation changes in ischemic zone during endovascular revascularization procedure either following angiosome concept or performing indirect revascularization. Methods. A prospective observational study was performed. Patients with critical limb ischemia and tissue loss due to chronic total occlusion of below the knee arteries were included. Endovascular revascularization was performed in all cases. Tissue oxygen saturation was observed intraoperatively using near-infrared spectroscopy. Tissue oxygenation changes near the ischemic wound were compared between direct and indirect revascularization groups. Results. This clinical trial included 30 patients with critical limb ischemia (Rutherford 5) and occluded below the knee arteries intended to treat. In 15 patients the procedure was performed according to angiosome, while the other half underwent indirect revascularization. Tissue oxygenation near the wound was monitored during the intervention. Greater oxygen saturation increase was observed in the group with direct revascularization (29% and 23% accordingly), however the difference between groups was not statistically significant (t-test for independent group, p = 0,544). Conclusions. The increase in tissue oxygen saturation differed very slightly in direct and indirect revascularization groups and the difference was statistically insignificant.

Angiosome-Guided Endovascular Revascularization for Treatment of Diabetic Foot Ulcers with Peripheral Artery Disease

Because diabetic foot ulcers (DFUs) are difficult to heal and cause huge economic losses to the society, accelerating their healing has become extremely important. The purpose of this study was to evaluate the effect of revascularization based on the angiosome concept on DFU. Between January 2018 and July 2020, 112 consecutive legs with DFUs, in 111 patients who were discharged from the vascular surgery department of our hospital were retrospectively evaluated. The legs were assigned to two groups depending on whether direct arterial flow to the foot ulcer based on the angiosome concept was achieved. Comparisons of the ulcer healing rate, mean time to ulcer healing, major amputation rate, survival rate, and major amputation-free survival rate between the angiosome direct revascularization (DR) and angiosome indirect revascularization (IR) groups were performed. DR was achieved in 71 legs (63%) compared with IR in 41 legs. The ulcer healing rate (70.4% in the DR group versus 34.1% in the IR group, P<0.01), the mean time to ulcer healing (7.01±4.26months versus 10.09±3.24months, P<0.01), the survival rate (90.1 vs. 53.7%, P<0.01), and the major amputation-free survival rate (81.7 vs. 48.8%, P<0.01) were significantly higher in the DR group than in the IR group. Undergoing DR did not significantly reduce the major amputations rate compared to IR (13.4 and 34.1%, respectively, P=0.15), but there might be a trend. In multivariate models, DR remained a significant predictor for ulcer healing (HR, 7.07; 95% confidence interval (CI), 6.54-7.60, P<0.01). Opening multiple infrapopliteal arteries in the DR group compared with restoring only one infrapopliteal artery did not significantly improve the ulcer healing rate (P=0.59), the mean time to ulcer healing (P=0.70), major amputation rate (P=0.83), the survival rate (P=0.31), and the major amputation-free survival rate (P=0.40). Attaining a direct arterial flow based on the angiosome concept may be important for ulcer healing, survival, and amputation-free survival in diabetic foot patients. Opening multiple infrapopliteal arteries in DR patients may not improve the ulcer healing, survival, major amputation or amputation-free survival compared with single DR vessel patency.

Clinical Effect of Revascularization Strategies and Pharmacologic Treatment on Long-Term Results in Patients with Advanced Peripheral Artery Disease with TASC C and D Femoropopliteal Lesions.

Background This study was to assess the clinical outcome and associated parameters of endovascular therapy (EVT group) and bypass surgery (bypass group) in patients with long femoropopliteal TransAtlantic Inter-Society Consensus II (TASC II) C and D peripheral artery disease (PAD). Methods 187 patients who underwent successful EVT or bypass surgery were assessed. The endpoints included the events of cardiovascular disease (CVD) and lower-extremity amputation (LEA), 3-year primary patency, and 3-year amputation-free survival (AFS). Results The 3-year primary and secondary patency rates were better in the bypass group (P=0.007 and P=0.039, respectively), while the incidences of LEA, new CVD events, and mortality were comparable between groups. Weighted multivariate Cox analyses showed that cilostazol treatment (hazard ratio (HR): 0.46, 95% confidence interval (CI): 0.3–0.72, P=0.001), statin treatment (HR: 0.54, 95% CI: 0.33–0.9, P=0.014), and direct revascularization (DR) (HR: 0.47, 95% CI: 0.29–0.74, P=0.001) were predictive factors of 3-year primary patency. Kaplan–Meier curve analyses of time-to-primary cumulative AFS showed that nondiabetes mellitus, mild PAD, and cilostazol and statin treatment were correlated with a superior 3-year AFS (log rank test, P=0.001, P < 0.001, P=0.009, and P=0.044, respectively). Conclusions Endovascular stenting based on the angiosome concept and bypass surgery provide comparable benefits for the treatment of long, advanced femoropopliteal lesions after a short follow-up period, whereas cilostazol therapy for more than 3 months, aggressive treatment of dyslipidemia, and surgical revascularization were associated with higher primary patency.

Evaluation of Tissue Perfusion by Wound Blush and 2D Color-Coded Digital Subtraction Angiography During Endovascular Intervention and Its Impact on Limb Salvage in Critical Limb Ischemia

Purpose: Critical limb ischemia (CLI) is an entity with high mortality if not properly treated. The primary aim of CLI revascularization is to enhance wound healing, which greatly depends on microvascular circulation. The available tools for assessment of revascularization success are deficient in the evaluation of local microvascular tissue perfusion, that wound blush (WB) reflects. A reliable technique that assesses capillary flow to foot lesions is needed. This study aims to assess WB angiographically at sites of interest in the foot after revascularization and its impact on limb salvage in CLI. Materials and Methods: 198 CLI patients (Rutherford category 5/6) with infrainguinal atherosclerotic lesions amenable for endovascular revascularization (EVR) were included. Limbs were directly or indirectly revascularized by EVR. Direct revascularization meant that successful revascularization of the area of interest according to the angiosome concept was achieved. A completion angiographic run was taken to assess WB. Patients were divided into 2 groups; positive and negative WB groups. In the event of a disagreement between the observational investigators, the digital subtraction angiography (DSA) series was analyzed for hemodynamic changes with a computerized 2D color-coded DSA (Syngo iFlow). Results: 176 limbs had successful revascularization in 157 patients. The successful revascularization rate was 88.9% (176/198), with technical failure encountered in 22 limbs. 121 patients had positive WB and 55 patients had negative WB. Direct revascularization of target areas was obtained in 98 limbs (55.7%). There was a significant difference in the rate of achieving direct flow to the lesion between the positive WB and negative WB groups (36.4% vs 19.3%, p≤0.001). We noticed a nonsignificant difference between patients who had direct revascularization of the foot lesion(s) and those who had indirect revascularization as regards limb salvage. Patients were followed up for 25.2 ± 12.7 months. By the end of the first year, limb salvage rate was significantly higher in patients who had positive WB (98% vs 63%, p<0.001, after 2 years (97% vs 58%, p<0.001) and after 3 years (94% vs 51.5%, p<0.001). Conclusions: WB is an important predictor and a prognostic factor for wound healing in CLI patients with soft tissue lesions.

Propensity-matched analysis does not support angiosome-guided revascularization of multilevel peripheral artery disease (PAD).

This retrospective comparative cohort study evaluated the clinical outcome of angiosome-guided endovascular arterial reconstructions in chronic limb-threatening ischemia (CLTI) due to multilevel peripheral artery disease (PAD). Patients treated in an endovascular fashion for CLTI with tissue loss due to multilevel PAD were analyzed. Limbs were classified as having undergone either angiosome-guided (direct) revascularization (DR) or nonangiosomic (indirect) revascularization (IR). DR was defined as uninterrupted in-line flow to the affected angiosome, revascularization through the pedal arch was also considered direct. Groups were adjusted with propensity score (PS) matching and compared for amputation-free survival (AFS), freedom from major adverse limb events (MALE), and healing rate at 12 months. A total of 174 patients (81 men, mean age 70.0 ± 10.4 y) were included. PS matching produced two groups of 55 patients each: DR (24 men, mean age 71.7 ± 10.7 y) and IR (26 men, mean age 72.0 ± 9.4 y). The matched groups had no significant differences in baseline variables. At 12 months there were no significant differences in AFS (73.2% vs 71.6%; p = 0.841), freedom from MALE (71.7% vs 66.1%; p = 0.617), and healing rate (72.7% vs 72.0%; p = 1.000) between DR and IR, respectively. This study failed to support the use of angiosome concept in CLTI due to multilevel disease.

The impact of an angiosome-targeted revascularization on healing rate, limb salvage and survival in critical limb threatening ischemia

Objective According to the angiosome concept ulcer healing and limb salvage should be superior if direct arterial flow to the source vessel of an affected angiosome is established compared to indirect flow where the angiosome is perfused by means of collaterals. The objective of this study was to evaluate the impact of direct versus indirect revascularization (DR/IR) in endovascular versus bypass surgery on ulcer healing, limb salvage and mortality. Materials and methods A retrospective analysis of both endovascular and bypass distal (below the knee) lower limb revascularizations for chronic limb-threatening ischemia (CLTI) between 1993 and 2014 was performed. Results The study population consisted of 126 endovascular and 198 bypass procedures. DR and IR were achieved in 57.4% and 42.6% limbs respectively. DR was not superior to IR regarding all three major endpoints when endovascular and bypass procedures were analyzed separately. Endovascular and bypass procedures resulted in comparable healing rates. All patients who did not achieve wound healing (HR 7.49; 95% CI 4.25–13.20, p = .0001) or needed to be treated with a bypass (HR 1.79; 95% CI 1.05–3.05, p = .034) were at an increased risk for major amputation. Increased mortality rate was noted after endovascular procedures (HR 1.45; 95% CI 1.04–2.00, p = .026). Conclusion This retrospective study with comparable results for DR and IR did not support the angiosome concept. Achieving wound healing remains critical in patients with CLTI to reduce major amputation rates. Overall the implications of the angiosome concept seem to be limited due to its feasibility in patients with CLTI.

An advanced ultrasound application used to assess peripheral vascular diseases: superb microvascular imaging.

Over the past several years, a novel ultrasound imaging modality termed superb microvascular imaging (SMI) has enabled visualization of microvessels. SMI ultrasound studies of peripheral artery diseases have significantly extended our knowledge of tissue microcirculation and the arterial microenvironments of atherosclerotic lesions. We here present an overview of current knowledge on the utility of SMI assessment of vascular diseases and highlight certain peripheral microcirculation disorders for which SMI is particularly valuable. The evidence indicates that SMI can detect intraplaque neovascularization and usefully assess carotid plaque vulnerability; vascularization of the carotid arterial wall detected by SMI is a potential marker of disease activity in patients with Takayasu arteritis; SMI reveals the foot microcirculation and yields a quantitative vascular index (in line with the angiosome concept); and, SMI may serve as an auxiliary diagnostic modality for hereditary hemorrhagic telangiectasia and Raynaud syndrome. In general, microcirculatory evaluation by SMI is an attractive field for future research on therapeutic strategies for peripheral vascular diseases.

Bifurcated bypass in severe chronic limb threatening ischaemia.

Revascularization according to the angiosome concept is of proven importance for limb salvage in chronic limb threatening ischaemia but it is not always practicable. Bifurcated bypasses could be considered as an option when an endovascular approach is not feasible or has already failed and a single bypass would not allow direct revascularization of the ischaemic area. Bifurcated bypasses are characterized by landing on two different arteries, the main artery (in direct continuity with the foot vessels) and the secondary one (perfusing the angiosome district). The aim of this study is to evaluate the safety and effectiveness of bifurcated bypass in chronic limb threatening ischaemia. Thirty-five patients were consecutively treated with a bifurcated bypass for chronic limb threatening ischaemia from January 2014 to December 2019 in a single vascular surgery centre. Data from clinical records and operative registers were collected prospectively in an electronic database and retrospectively analysed. Primary and primary assisted bypass patency, amputation-free survival, morbidity and mortality rates at 12 and 24 months were analysed. Mean follow-up period was 25.1 months (range 2-72 months). Thirty-six bifurcated bypasses were performed on 35 patients (age 75.3 ± 7.2 years; 69.4% were male). According to Wound, Ischemia, foot Infection classification 22.2% belonged to stage 3 and 77.8% to stage 4 and the mean Rutherford's class was 5.1 ± 0.7. Immediate technical success was 100%. Early mortality and morbidity rates were respectively 5.5%, and 33.3%; foot surgery was performed in 50% of cases with wound healing in all patients. Primary patency and primary assisted bypass patency were 96.7% and 100% at 6 months; 85.2% and 92% at 12 months, 59.9% and 73.4% at 24 months, respectively. Amputation-free survival at 12 and 24 months was, respectively, 95.6% and 78.8%. Overall survival rates at 12 and 24 months were respectively 94.4% and 91.6%. Bifurcates bypass can provide good results in patients with chronic limb threatening ischaemia without endovascular option, especially in diabetic ones. Bifurcated bypass is a complex surgical solution, both to be planned and performed, and it is quite invasive for frail patients that should be accurately selected.