Clinical outcome of angiosome-oriented infrapopliteal percutaneous transluminal angioplasty for isolated infrapopliteal lesions in patients with critical limb ischemia

Comparison of endovascular infrapopliteal revascularisation strategies based on the angiosome model in diabetics with CLTI

Background: Infrapopliteal endovascular interventions (EVT) strategies in diabetic patients are still in debate because the lesions are more likely to be diffuse with a different pattern of collateral arteries ranging from reduced to normal caliber. The aim of this all-comers study was to analyse the outcome of two different infrapopliteal EVT strategies (Group I: angiosome-based direct revascularization - DR vs. Group II: complete (direct + indirect) revascularization strategy - CR) in diabetic patients with chronic limb-threatening ischemia (CLTI) in 2 time-periods. Furthermore we analysed the outcome if DR or CR failed and only indirect revascularization (IR) or no revascularization was possible. Both groups were differentiated in patients with collaterals, defined as an intact pedal arch (immediate or after pedal PTA). Patients and methods: The database includes 91 consecutive EVT with two intrapopliteal interventional strategies performed in 68 diabetic patients (pts. 24 female, 44 male, mean age 73±10 years) between 2013-2016 and 2017-2022. Positive clinical outcome was defined as wound healing with or w/o minor amputation, combined with a symptom improvement to Rutherford category 0 or 1 after 6 months. The clinical outcome proportions were compared using the Fisher's exact test. Results: Successful DR (59%) and successful CR (47%) strategy demonstrated a similar positive clinical outcome (92.6% vs. 90.5%; p=0.594). Indirect revascularization (Group I: 26%; Group II: 44%) showed a significantly lower positive outcome in comparison to a successful DR as well as CR strategy (33.3% vs. 92.6%, p=0.0003; 40% vs 90.5%, p=0.001). IR outcome improved by the presence of collaterals (66.7% vs. 30.8%). Conclusions: In case of successful intervention, both strategies (DR and CR) yielded a similarly high proportion of positive clinical outcome. The role of collaterals and the pedal arch on the clinical outcome are important in patients in whom only IR was possible.

Effectiveness of revascularisation for the ulcerated foot in patients with diabetes and peripheral artery disease: A systematic review

INTRODUCTION

Peripheral artery disease (PAD) is associated with an increased likelihood of delayed or non-healing of a diabetes-related foot ulcer, gangrene, and amputation. The selection of the most effective surgical technique for revascularisation of the lower limb in this population is challenging and there is a lack of conclusive evidence to support the choice of intervention. This systematic review aimed to determine, in people with diabetes and tissue loss, if direct revascularisation is superior to indirect revascularisation and if endovascular revascularisation is superior to open revascularisation for the outcomes of wound healing, minor or major amputation, and adverse events including mortality.

METHODS

Title and abstract searches of Medline, Embase, PubMed, and EBSCO were conducted from 1980 to 30th November 2022. Cohort and case-control studies and randomised controlled trials reporting comparative outcomes of direct (angiosome) revascularisation (DR) and indirect revascularisation (IR) or the comparative outcomes of endovascular revascularisation and open or hybrid revascularisation for the outcomes of healing, minor amputation, and major amputation in people with diabetes, PAD and tissue loss (including foot ulcer and/or gangrene) were eligible. Methodological quality was assessed using the Cochrane risk-of-bias tool for randomised trials, the ROBINS-I tool for non-randomised studies, and Newcastle-Ottawa Scale for observational and cohort studies where details regarding the allocation to intervention groups were not provided.

RESULTS

From a total 7086 abstracts retrieved, 26 studies met the inclusion criteria for the comparison of direct angiosome revascularisation (DR) and indirect revascularisation (IR), and 11 studies met the inclusion criteria for the comparison of endovascular and open revascularisation. One study was included in both comparisons. Of the included studies, 35 were observational (31 retrospective and 4 prospective cohorts) and 1 was a randomised controlled trial. Cohort study quality was variable and generally low, with common sources of bias related to heterogeneous participant populations and interventions and lack of reporting of or adjusting for confounding factors. The randomised controlled trial had a low risk of bias. For studies of DR and IR, results were variable, and it is uncertain if one technique is superior to the other for healing, prevention of minor or major amputation, or mortality. However, the majority of studies reported that a greater proportion of participants receiving DR healed compared with IR, and that IR with collaterals may have similar outcomes to DR for wound healing. For patients with diabetes, infrainguinal PAD, and an adequate great saphenous vein available for use as a bypass conduit who were deemed suitable for either surgical procedure, an open revascularisation first approach was superior to endovascular therapy to prevent a major adverse limb event or death (Hazard Ratio: 0.72; 95% CI 0.61-0.86). For other studies of open and endovascular approaches, there was generally no difference in outcomes between the interventions.

CONCLUSIONS

The majority of available evidence for the effectiveness of DR and IR and open and endovascular revascularisation for wound healing and prevention of minor and major amputation and adverse events including mortality in people with diabetes, PAD and tissue loss is inconclusive, and the certainty of evidence is very low. Data from one high quality randomised controlled trial supports the use of open over endovascular revascularisation to prevent a major limb event and death in people with diabetes, infrainguinal disease and tissue loss who have an adequate great saphenous vein available and who are deemed suitable for either approach.

Oxygen Saturation Increase in Ischemic Wound Tissues after Direct and Indirect Revascularization

BACKGROUND

The primary approach for treating ischemic wounds is restoring oxygen supply to the ischemic region. While direct angiosomal revascularization is often associated with better post-operative wound healing and limb salvage, its superiority over non-angiosomal revascularization remains controversial. This study aimed to compare intraoperative tissue oxygen saturation changes in ischemic zones following either direct or indirect revascularization in below-the-knee arteries.

METHODS

This prospective observational study included patients undergoing direct and indirect below-the-knee endovascular revascularizations. Assignment to the groups was not randomized. Near-infrared spectroscopy was used to monitor rSO2 changes near the ischemic wounds intraoperatively. The changes were compared between the groups.

RESULTS

15 patients (50%) underwent direct angiosomal revascularization, while an equal number of patients underwent indirect revascularization. Overall, a statistically significant increase in regional oxygen saturation was observed after revascularization (p = 0.001). No statistically significant difference was found between the direct and indirect revascularization groups (p = 0.619).

CONCLUSIONS

This study revealed a minor difference in the oxygen saturation increase between the angiosomal and non-angiosomal revascularization groups. Such a finding indicates that the clinical significance of angiosomal revascularization is negligible and might be concealed by confounding factors, such as the vessel diameter and outflow impact on the restenosis rate.

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.

Overcoming ischemia in the diabetic foot: Minimally invasive treatment options

As the global burden of diabetes is rapidly increasing, the incidence of diabetic foot ulcers is continuously increasing as the mean age of the world population increases and the obesity epidemic advances. A significant percentage of diabetic foot ulcers are caused by mixed micro and macro-vascular dysfunction leading to impaired perfusion of foot tissue. Left untreated, chronic limb-threatening ischemia has a poor prognosis and is correlated with limb loss and increased mortality; prompt treatment is required. In this review, the diagnostic challenges in diabetic foot disease are discussed and available data on minimally invasive treatment options such as endovascular revascularization, stem cells, and gene therapy are examined.

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

BACKGROUND

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).

METHODS

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.

RESULTS

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.

CONCLUSION

This study failed to support the use of angiosome concept in CLTI due to multilevel disease.

A systematic review and meta-analysis of endovascular angiosomal revascularization in the setting of collateral vessels

OBJECTIVE

Endovascular procedures for targeted treatment of lower extremity wounds can be subdivided as direct revascularization (DR), indirect revascularization (IR), and IR via collateral flow (IRc). Although previous systematic reviews assert superiority of DR when compared with IR, the role of collateral vessels in clinical outcomes remains to be defined. This systematic review and meta-analysis aims to define the usefulness of DR, IR, and IRc in treatment of lower extremity wounds with respect to (1) wound healing, (2) major amputation, (3) reintervention, and (4) all-cause mortality.

METHODS

A meta-analysis was performed in accordance with PRISMA guidelines. Ovid MEDLINE was queried for records pertaining to the study question using appropriate Medical Subject Heading terms. Studies were limited to those using DR, IR, or IRc as a primary intervention and reporting information on at least one of the primary outcomes of interest. No limitation was placed on year of publication, country of origin, or study size. Studies were assessed for validity using the Newcastle-Ottawa Scale. Study characteristics and patient demographics were collected. Data representing the primary outcomes-wound healing, major amputation, reintervention, and all-cause mortality-were collected for time points ranging from one month to four years following intervention. A meta-analysis on sample size-weighted data assuming a random effects model was performed to calculate odds ratios (ORs) for the four primary outcomes at various time points.

RESULTS

We identified 21 studies for a total of 4252 limbs (DR, 2231; IR, 1647; IRC, 270). Overall wound healing rates were significantly superior for DR (OR, 2.45; P = .001) and IRc (OR, 8.46; P < .00001) compared with, IR with no significant difference between DR and IRc (OR, 1.25; P = .23). The overall major amputation rates were significantly superior for DR (OR, 0.48; P < .00001) and IRc (OR, 0.44; P = .006) compared with IR, with DR exhibiting significantly improved rates compared with IRc (OR, 0.51; P = .01). The overall mortality rates showed no significant differences between DR (OR, 0.89; P = .37) and IRc (OR, 1.12; P = .78) compared with IR, with no significant difference between DR and IRc (OR, 0.54; P = .18). The overall reintervention rates showed no significant difference between DR and IR (OR, 1.05; P = .81), with no studies reporting reintervention outcomes for IRc.

CONCLUSIONS

Both DR and IRc offer significantly improved wound healing rates and major amputation rates compared with IR when used to treat critical limb ischemia. Although DR should be the preferred method of revascularization, IRc can offer comparable outcomes when DR is not possible. This analysis was limited by a small sample size of IRc limbs, a predominance of retrospective studies, and variability in outcome definitions between studies.

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.

Effectiveness of revascularisation of the ulcerated foot in patients with diabetes and peripheral artery disease: A systematic review

In patients with diabetes, foot ulceration and peripheral artery disease (PAD), it is often difficult to determine whether, when and how to revascularise the affected lower extremity. The presence of PAD is a major risk factor for non-healing and yet clinical outcomes of revascularisation are not necessarily related to technical success. The International Working Group of the Diabetic Foot updated systematic review on the effectiveness of revascularisation of the ulcerated foot in patients with diabetes and PAD is comprised of 64 studies describing >13 000 patients. Amongst 60 case series and 4 non-randomised controlled studies, we summarised clinically relevant outcomes and found them to be broadly similar between patients treated with open vs endovascular therapy. Following endovascular revascularisation, the 1 year and 2 year limb salvage rates were 80% (IQR 78-82%) and 78% (IQR 75-83%), whereas open therapy was associated with rates of 85% (IQR 80-90%) at 1 year and 87% (IQR 85-88%) at 2 years, however these results were based on a varying combination of studies and cannot therefore be interpreted as cumulative. Overall, wound healing was achieved in a median of 60% of patients (IQR 50-69%) at 1 year in those treated by endovascular or surgical therapy, and the major amputation rate of endovascular vs open therapy was 2% vs 5% at 30 days, 10% vs 9% at 1 year and 13% vs 9% at 2 years. For both strategies, overall mortality was found to be high, with 2% (1-6%) perioperative (or 30 day) mortality, rising sharply to 13% (9-23%) at 1 year, 29% (19-48%) at 2 years and 47% (39-71%) at 5 years. Both the angiosome concept (revascularisation directly to the area of tissue loss via its main feeding artery) or indirect revascularisation through collaterals, appear to be equally effective strategies for restoring perfusion. Overall, the available data do not allow us to recommend one method of revascularisation over the other and more studies are required to determine the best revascularisation approach in diabetic foot ulceration.

Healing of Diabetic Neuroischemic Foot Wounds With vs Without Wound-Targeted Revascularization: Preliminary Observations From an 8-Year Prospective Dual-Center Registry

Purpose: To assess the clinical efficacy of endovascular angiosome-oriented wound-targeted revascularization (WTR) vs indirect (wound-indifferent) revascularization (IR) in diabetic patients with neuroischemic foot ulcers. Materials and Methods: Between April 2009 and July 2017, 167 diabetic patients (mean age 72.8 years; 137 men) with chronic limb-threatening ischemia (Rutherford category 5) and foot wounds (Wagner 2-4) in 194 limbs were prospectively registered and scheduled for primary infragenicular endovascular treatment. Specific angiosome source artery reperfusion sustained by patent foot arches or arterial-arterial connections was attempted initially. If this approach failed, topographic revascularization via available collaterals (WTRc) and IR were sequentially attempted. Results: Reperfusion was successful in 176 (91%) of 194 limbs (113 with WTR, 28 with WTRc, and 35 with IR); the global angiosome-oriented technical success (WTR and WTRc) was 73% (141/194). The mean follow-up was 10.9±0.7 months (range 3-12.5). Over 1 year, 102 (58%) of the 176 successfully treated limbs experienced wound healing [79/113 (70%) in the WTR group, 15/28 (54%) in the WTRc group, and 7/35 (20%) in the IR group; p=0.011]. The mean time to healing was 6.8±0.4 months in the WTR group, 7.9±0.6 months in the WTRc group, and 9.8±0.7 months in the IR group (p=0.001). Relapses were noted in 18 (16%) WTR limbs, 5 (18%) WTRc limbs, and 6 (17%) IR limbs. Comparison between WTR and IR and WTRc vs IR showed improved cicatrization in the angiosome-oriented groups (p<0.05). Major adverse limb events (MALE) and limb salvage were different between WTR and WTRc and between WTR and IR groups (p<0.05), while WTRc vs IR was not. Amputation-free survival was not influenced by the revascularization strategy (p=0.093). Conclusion: Wound healing in diabetic patients with chronic limb-threatening ischemia appeared to be improved by intentional wound-targeted revascularization, but no uniform benefit concerning MALE or limb preservation was observed. IR still represents an alternative for limb salvage in cases in which angiosome-guided revascularization fails.

Bypass versus endovascular intervention for healing ischemic foot wounds secondary to tibial arterial disease

OBJECTIVE

Pedal (inframalleolar) bypass is a long-standing therapy for tibial arterial disease in patients with ischemic tissue loss. Endovascular tibial intervention is an appealing alternative with lower risks of perioperative mortality or complications. Our objective was to compare the effectiveness of these two treatment modalities with respect to patency and limb-related clinical outcomes.

METHODS

We performed a retrospective chart review of patients presenting between 2006 and 2013 with ischemic foot wounds and infrapopliteal arterial disease who underwent a revascularization procedure (either open surgical bypass to an inframalleolar target or endovascular tibial intervention). Data were collected on baseline demographics and comorbidities, procedural details, and postprocedure outcomes. The primary outcome was successful healing of the index wound, with mortality, major amputation, and patency assessed as secondary outcomes.

RESULTS

We identified 417 patients who met our eligibility criteria; 105 underwent surgical bypass and 312 underwent endovascular intervention, with mean follow-up of 25.0 and 20.2 months, respectively (P = .08). The endovascular patients were older at baseline (P = .009), with higher rates of hyperlipidemia (P = .02), prior cerebrovascular accidents (P = .04), and smoking history (P = .04). Within 30 days postoperatively, there was no difference in mortality (P = .31), but bypass patients had longer hospital length of stay (P < .0001), higher rate of discharge to nursing facility (P < .001), and higher rates of myocardial infarctions (P = .03) and wound complications (P < .001). At 6 months, the rate of wound healing was 22.4% in the bypass group compared with 29.0% in the endovascular group (P = .02). At 1 year, survival was higher after bypass (86.2% vs 70.4%; P < .0001), but freedom from major amputation was similar (84.9% vs 82.8%; P = .42). Primary patency (53.1% vs 38.2%; P = .002) and primary assisted patency (76.6% vs 51.7%; P < .0001) were higher in the bypass group, but there was no difference in secondary patency (77.3% vs 73.8%; P = .13).

CONCLUSIONS

Endovascular tibial intervention is associated with poorer primary patency but similar secondary patency and wound healing rates compared with the "gold standard" of surgical bypass to a pedal target. In patients with tibial arterial disease, endovascular intervention should be considered a lower risk alternative to pedal bypass that provides similar clinical outcomes.

The comparative efficacy of angiosome-directed and indirect revascularisation strategies to aid healing of chronic foot wounds in patients with co-morbid diabetes mellitus and critical limb ischaemia: a literature review

BACKGROUND

Ischaemic ulcerations have been reported to persist and/or deteriorate despite technically successful revascularisations; a higher incidence of which affects patients with diabetes and critical limb ischaemia. In the context of wound healing, it is unclear if applications of the angiosome concept in 'direct revascularisation' (DR) would be able to aid the healing of chronic foot ulcerations better than the current 'best vessel' or 'indirect revascularisation' (IR) strategy in patients with co-morbid diabetes and critical limb ischaemia.

METHODS

A literature search was conducted in eight electronic databases, namely AMED, CINAHL, The Cochrane Library, ProQuest Health & Medicine Complete, ProQuest Nursing & Allied Health Source, PubMed, ScienceDirect and TRIP database. Articles were initially screened against a pre-established inclusion and exclusion criteria to determine eligibility and subsequently appraised using the Newcastle-Ottawa Scale.

RESULTS

Five retrospective studies of varying methodological quality were eligible for inclusion in this review. Critical analysis of an aggregated population (n = 280) from methodologically stronger studies indicates better wound healing outcomes in subjects who had undergone DR as compared to IR (p < 0.001; p = 0.04). DR also appears to result in a nearly twofold increase in probability of wound healing within 12 months (hazard ratio, 1.97; 95% CI, 1.34-2.90). This suggests that achieving direct arterial perfusion to the site of ulceration may be important for the healing of chronic diabetic foot ulcerations.

CONCLUSION

Incorporating an angiosome-directed approach in the lower limb revascularisation strategy could be a very useful adjunct to a solely indirect approach, which could increase the likelihood of wound healing. With the limited data currently available, findings appear promising and merit from further investigation. Additional research to form a solid evidence base for this revised strategy in patients with co-morbid diabetes and critical limb ischaemia is warranted.

Angiosome-directed revascularization in patients with critical limb ischemia

OBJECTIVE

Direct revascularization (DR), according to the angiosome concept, provides direct blood flow to the site of tissue loss in patients with critical limb ischemia (CLI). DR may lead to improved outcomes; however, evidence for this is controversial. This systematic review and meta-analysis investigated the outcomes of surgical and endovascular DR compared with indirect revascularization (IR) in patients with CLI.

METHODS

A systematic review was undertaken using the Cochrane Collaboration specified tool, and a meta-analysis was done according to the MOOSE (Meta-analysis of Observational Studies in Epidemiology) criteria. The electronic databases of MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were systematically searched for studies of DR compared with IR in patients with CLI with tissue loss. All articles were critically assessed for relevance, validity, and availability of data regarding patient and lesion characteristics and outcomes. When possible, data were systematically pooled, and a meta-analysis was performed for wound healing, major amputation, amputation-free survival, and overall survival.

RESULTS

Of 306 screened abstracts, 19 cohort studies with 3932 patients were included. Nine scored 7 or higher on the Newcastle-Ottawa score. DR significantly improved wound healing (risk ratio [RR], 0.60; 95% confidence interval [CI], 0.51-0.71), major amputation (RR, 0.56; 95% CI, 0.47-0.67), and amputation-free survival rates (RR, 0.83; 95% CI, 0.69-1.00) compared with IR. This significance was lost in major amputation on sensitivity analysis for bypass studies. No significant difference was found in overall survival. In studies stratifying for collaterals, no differences between DR and IR were found in wound healing or major amputations in the presence of collaterals.

CONCLUSIONS

DR significantly improves wound healing and major amputation rates after endovascular treatment in patients with CLI, supporting the angiosome theory. In the presence of collaterals, outcomes after IR are similar to outcomes after DR. Alternatively, patients without collaterals may benefit even more from DR as a primary treatment strategy. The angiosome theory is less applicable in bypass surgery, because bypasses are generally anastomosed to the least affected artery, with runoff passing the ankle to maintain bypass patency.