Angiosome perfusion of the foot: An old theory or a new issue?

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

BACKGROUND

Diabetes is strongly correlated with the development of critical limb ischemia, 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 critical limb ischemia, 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.

METHODS

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 Global Limb Anatomic Staging System stage and revascularization procedures were considered secondary outcomes.

RESULTS

Data from 117 limbs of 114 diabetic patients with neuroischemic diabetic foot were evaluated. There was no significant difference between targeted and nontargeted 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).

CONCLUSIONS

Although angiosome-guided revascularization did not demonstrate significantly higher healing rates at 12 months, there appears to be a trend toward faster healing.

Validation of MRI assessment of foot perfusion for improving treatment of patients with peripheral artery disease

INTRODUCTION

Information on tissue perfusion in the foot is important when treating patients with chronic limb-threatening ischemia. This study aims to test the reliability of different magnetic resonance sequences when measuring perfusion in the foot.

METHODS

Sixteen healthy volunteers had their right foot scanned in a test/retest study with six different magnetic resonance sequences (BOLD, multi-echo gradient echo (mGRE), 2D and 3D pCASL, PASL FAIR, and DWI with intravoxel incoherent motion (IVIM) with quantitative measurements of perfusion. For five sequences, cuff-induced ischemia followed by a hyperactive response was measured. Images of the feet were segmented into angiosomes and perfusion data were extracted from the five angiosomes.

RESULTS

BOLD, PASL FAIR, mGRE, and DWI with IVIM had low mean differences between the first and second scans, while the results of 2D and 3D pCASL had the highest differences. Based on a paired t-test, BOLD, and FAIR were able to distinguish between perfusion and no perfusion in all angiosomes with p-values below 0.01. This was not the case with 2D and 3D pCASL with p-values above 0.05 in all angiosomes. The mGRE could not distinguish between perfusion and no perfusion in the lateral side of the foot.

CONCLUSION

BOLD, mGRE, pASL FAIR, and DWI with IVIM seem to give more robust results compared to 2D and 3D pCASL. Further studies on patients with peripheral artery disease should explore if the sequences can have clinical relevance when assessing tissue ischemia and results of revascularization.

IMPLICATIONS FOR PRACTICE

This study provides knowledge that could be used to improve the diagnosis of patient with chronic limb-threatening ischemia to explore tissue perfusion.

Duplex ultrasound and pedal acceleration time as tools to evaluate foot perfusion: a literature review

Currently, the standard non-invasive test for diagnosing Peripheral Arterial Disease is the Ankle-Brachial Index. However, this test becomes unfeasible in a certain population. New evidence proposes the pedal acceleration time, an ultrasound index, as an alternative test. An integrative bibliographic review was carried out between June 3, 2022 and January 8, 2023, to investigate this new index as a tool to assess foot perfusion. Papers published in English, Portuguese, or Spanish between 2012 and 2022 were searched on PubMed, Google Scholar, and Scielo, using the keywords "Peripheral Arterial Disease" AND "Acceleration Time" AND (Pedal OR Plantar). Research that didn't assess foot perfusion using the methods of interest or did not present human data and also case series or reports were excluded. Seven out of the sixty-six articles identified in the searches were selected for the review, all of which had notable methodological limitations. Pedal acceleration time seems to be able to diagnose and stratify and may reflect prognosis.

A portable optical pulsatile flowmetry demonstrates strong clinical relevance for diabetic foot perfusion assessment

We present a robust, cost-effective (<2000 USD), and portable optical diffuse speckle pulsatile flowmetry (DSPF) device with a flexible handheld probe for deep tissue blood flow measurement in the human foot as well as a first-in-man observational clinical study using the proposed optical device for tissue ischemia assessment and peripheral artery disease (PAD) diagnosis. Blood flow in tissue is inherently pulsatile in nature. However, most conventional methods cannot measure deep tissue-level pulsatile blood flow noninvasively. The proposed optical device can measure tissue-level pulsatile blood flow ∼6 mm underneath the skin surface. A new quantitative tissue perfusion index (TPIDSPF) based on frequency domain analysis of the pulsatile blood flow waveform is defined to assess tissue ischemia status. Through a clinical study involving 66 subjects, including healthy individuals and diabetes patients with and without PAD, TPIDSPF demonstrated strong correlations of 0.720 with transcutaneous tissue partial oxygen pressure (TcPO2) and 0.652 with toe-brachial index (TBI). Moreover, among the three methods, TPIDSPF demonstrated the highest area under the curve for PAD diagnosis among diabetes patients, with a notable value of 0.941. The promising clinical results suggest that the proposed optical method has the potential to be an effective clinical tool for identifying PAD among the diabetic cohort.

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.

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.

Chronic Limb-Threatening Ischemia in Patients with Type 2 Diabetes: Revascularization Index as a Predictor for Primary Endovascular Intervention Outcome

Purpose

Chronic limb-threatening ischemia in patients with diabetes is associated with a high risk of adverse outcomes. The associated co-morbidities, the heterogeneity of foot presentation and the distribution of atherosclerotic lesions led to the emergence of multiple revascularization strategies and scoring systems to improve management outcomes. This study aimed to introduce a new index, the revascularization index (RI), and to assess its predictive value for the outcomes of primary endovascular intervention in patients with type 2 diabetes presenting with chronic limb-threatening ischemia.

Patients and Methods

A retrospective electronic medical records review was conducted for patients with type 2 diabetes presenting with chronic limb-threatening ischemia managed at King Abdullah University Hospital by primary endovascular interventions between January 2014 and August 2019. The RI was analyzed for its predictive value for the treatment outcomes.

Results

A total of 187 patients were included in this study, with a major lower limb amputation rate of 19.3%. The performance of the RI was excellent in predicting secondary revascularization (AUC = 0.80, 95% CI: 0.73-0.86, p-value < 0.001), good to predict major amputation (AUC = 0.76, 95% CI: 0.67-0.85, p-value = 0.047), and poor in predicting death (AUC = 0.46, 95% CI: 0.40-0.55, p-value = 0.398). RI of <1.21 was significantly associated with a higher risk of major lower limb amputation (HR = 5.8, 95% CI: 1.25-26.97, p-value < 0.025), and RI of < 1.3 was associated with a higher risk for secondary revascularization.

Conclusion

The RI can be used to predict major adverse lower limb events (MALE). It might be used as a guide for the extent of endovascular interventions for diabetic chronic limb-threatening ischemia with multi-level outflow atherosclerotic disease.

Outcome of a Simple Novel Technique to Reduce Soft Tissue Complications in Open Tendoachilles Injury: A Series of 20 Patients

Introduction

Open tendoachilles injuries are rare and associated with significant soft tissues complications. The objective of the present study was to assess the clinical outcome and safety of a simple and minimally invasive technique, with a goal to assess if it may help minimise flap and wound related complications in open tendoachilles injuries.

Materials and methods

This prospective study of four years duration included 20 patients with open tendoachilles injuries managed with a simple minimally invasive tunnel technique. The primary outcome variable was occurrence of a major soft tissue complication. The secondary outcome variables included functional outcome measured using AOFAS Ankle hind foot score, re-rupture of tendoachilles and need for revision surgery.

Results

None of the patients in the present series developed a serious soft tissue complication. Based upon the AOFAS hind foot scoring system, good to excellent outcome was achieved in 19 (95%) patients. All the patients were able to perform tip toe walking at six months post-surgery. None of the patients had a re-rupture of the tendoachilles and no patient needed a revision surgery. The complications encountered include thickening of the tendon at the repair site (15%), superficial wound infection (5%), stitch granuloma (5%) and hypertrophic scar (5%).

Conclusion

This technique seems to be promising in reducing the soft tissue complications associated with the surgical management of open tendoachilles injuries. Most patients had a good final clinical outcome. The technique is safe, simple and reproducible. However, further randomised control studies with a larger sample size assessing the technique are recommended.

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.

Peripheral Arterial Disease in Persons with Diabetic Foot Ulceration: a Current Comprehensive Overview

In developed countries, the prevalence of persons with diabetes and peripheral arterial disease (PAD) is approximately 50%. The presence of PAD is associated with non-healing ulcers, major amputation, cardiovascular morbidity, and mortality. It is estimated that persons with diabetes, foot ulceration and PAD have 50% of 5-years mortality rate. Therefore, subjects with ischemic diabetic foot ulcers (DFUs) should be considered a special group of patients with specific clinical characteristics, general health status and prognosis. In persons with ischemic DFUs, an early diagnosis and treatment are mandatory to reduce the risk of worse outcomes such as major amputation. Revascularization of occluded lower extremity arteries is the main treatment to restore blood flow in the foot and promote wound healing. Nonetheless, there are several unmet needs in the management of diabetic subjects with PAD and foot ulceration as medical therapy, diagnostic criteria and indications for revascularization, revascularization strategy and technical approach as well as the management of no-option critical limb ischemia patients. It is a common opinion that there is an evolution of PAD features in diabetic persons, which seems to present a more aggressive pattern. This may be related to the frequent presence of concomitant comorbidities such as renal failure which could influence the characteristics of atherosclerotic plaques and their distribution. The aim of this review is to commence a complete overview and state of the art in the treatment of patients with diabetes, PAD, and foot ulceration and to describe the current challenges and future perspectives.

Angiosome～From the Standpoint of Bypass Surgery

Although several studies showed that angiosome-guided endovascular treatment improved wound healing and major amputation rates in patients with chronic limb-threatening ischemia (CLTI), effectiveness of the angiosome concept to the treatment of ischemic foot remains to be elucidated, especially in bypass surgery. Arterial anatomy of the foot and ankle shows that there are multiple supplementary circulation including arterial–arterial connections and choke nexus, which indicates angiosome concept may carry limited importance in bypass surgery for CLTI. On the other hand, patients with diabetes or renal dysfunction have partial occlusion of arterial–arterial connections and, therefore, quite a few patients with CLTI in Japan may present with limited but impaired supplementary circulation around the ankle. This article reviews the arterial anatomy and circulation of the foot and ankle and discusses availability and limitations of angiosome-guided bypass surgery.