Immediate changes of angiosome perfusion during tibial angioplasty

Optimizing Lower Extremity Local Flap Reconstruction in Peripheral Vascular Disease

BACKGROUND

Local flaps remain a valuable reconstructive tool as a means for limb salvage for patients with advanced arterial disease. Our single-center, retrospective cohort study aims to compare the outcomes of different patterns of blood flow affected by vascular disease to pedicles in local flap reconstruction of the foot and ankle.

METHODS

A retrospective review of 92 patients and 103 flaps was performed. On angiograms, pattern of blood flow to the flap pedicle was determined to be direct inline flow (DF) or indirect flow (IF). Patterns of IF were either by arterial-arterial connections (AC) or unnamed randomized collaterals (RC). Primary outcomes were immediate flap success and limb salvage. Comparative analyses were performed using the χ2 and Fisher tests for categorical variables.

RESULTS

Among all flaps, 73.8% (n = 76/103) had DF and 26.2% (n = 27/103) had IF. Both groups experienced similar rates of immediate flap success (DF = 97.3% vs IF = 92.6%, P = 0.281) and limb salvage (DF = 75.% vs IF = 66.7%, P = 0.403). However, the rate of contralateral amputation was significantly higher in the IF group (26.9% vs 5.3%, P = 0.006). When comparing the 3 distinct patterns of blood flow (DF vs AC vs RC), pedicled flaps were more commonly supplied by DF and AC, while random pattern flaps were more commonly supplied by RC (P = 0.042).

CONCLUSIONS

Alternative routes of revascularization can maintain local flap viability and achieve similar rates of limb salvage but risks contralateral amputation. We found that pedicled and local muscle flaps require inline blood flow or blood supply by ACs. Meanwhile, random pattern flap can be supported by random collaterals.

The Effect of Revascularization on Lower Limb Circulation Parameters in Symptomatic Peripheral Arterial Disease

Background: The prevalence of peripheral arterial disease and the number of revascularization procedures performed in symptomatic patients are steadily increasing. However, uncertainties remain regarding hemodynamic monitoring after revascularization and the prediction of clinical outcomes. This study aimed to investigate hemodynamic parameters with a focus on the microvasculature. Methods: This prospective, single-center study included 29 patients (15 with intermittent claudication [IC] and 14 with chronic limb-threatening ischemia [CLTI]). Before and after the revascularization procedure, in addition to the ankle-brachial index (ABI), microperfusion parameters, including microvascular blood flow, capillary oxygen saturation (SO2), and relative hemoglobin content (rHb), were assessed with lightguide spectrophotometry combined with laser Doppler flowmetry using an oxygen-to-see (O2C) device in the horizontal and elevated leg positions. Results: At baseline, SO2 in the elevated leg position was significantly lower in patients with CLTI than in those with IC (p = 0.0189), whereas the other microcirculatory parameters and ABI values were not significantly different. Patients with diabetes mellitus had a higher flow rate than those without in the horizontal leg position (p = 0.0162) but not in the elevated leg position. After successful revascularization, the flow increased immediately and significantly in both positions, whereas SO2, rHb, and the ABI did not. Conclusions: Elevated leg SO2 was significantly lower in CLTI than in clinically compensated peripheral arterial disease, whereas microvascular flow was a suitable surrogate parameter indicating successful revascularization. In studies using surgical or interventional revascularization procedures, noninvasive hemodynamic monitoring of the microcirculation at the foot level might be beneficial.

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.

Intermittent negative pressure therapy in patients with no-option chronic limb-threatening ischemia

Background: Aim of this study was to assess the influence of intermitted negative pressure (INP) therapy on the foot microcirculation in patients with no-option CLTI. Patients and methods: CLTI patients defined as no option for revascularization on the basis of an interdisciplinary vascular board decision (interventional radiology, vascular surgery) were included in this study. INP therapy was performed at home. Therapy regime was: 1 hour twice daily. Follow-up was after 6 weeks and 3 months. Microcirculation measurement was performed by laser Doppler flowmetry and white light spectrometry (oxygen to see, O2CTM). Following parameters were evaluated: oxygen saturation (sO2 in%), relative hemoglobin (rHb) and flow (in arbitrary units A.U.). Additionally the clinical outcome of the patients was assessed. Results: From September 2020 to June 2022, 228 patients were screened. In total 19 patients (13 men, 6 women, mean age was 73.95 years) were included. 6 weeks after INP therapy the microcirculation showed a significant improvement for the parameter sO2 (%) (p=0.004). After 3 months a non-significant decrease compared to 6 weeks follow-up was seen for the parameter sO2; however, the perfusion was still improved compared to baseline measurement. With regard to the microperfusion values flow (AU) and hemoglobin (AU), the changes were not significant. Clinically, the patients reported a significant reduction of rest pain after therapy (p=0.005). Conclusions: INP therapy in no-option CLTI patients showed a significant improvement of the skin perfusion after 6 weeks. Therefore, INP therapy might have therapeutic potential in these critical ill patients.

Investigation of Different Methods of Intraoperative Graft Perfusion Assessment during Kidney Transplantation for the Prediction of Delayed Graft Function: A Prospective Pilot Trial

Delayed graft function (DGF) after renal transplantation is a relevant clinical problem affecting long-term organ function. The early detection of patients at risk is crucial for postoperative monitoring and treatment algorithms. In this prospective cohort study, allograft perfusion was evaluated intraoperatively in 26 kidney recipients by visual and formal perfusion assessment, duplex sonography, and quantitative microperfusion assessment using O2C spectrometry and ICG fluorescence angiography. The O2C tissue spectrometry device provides a quantitative method of microperfusion assessment that can be employed during kidney transplantation as an easy-to-use and highly sensitive alternative to ICG fluorescence angiography. Intraoperative microvascular flow and velocity in the allograft cortex after reperfusion predicted DGF with a sensitivity of 100% and a specificity of 82%. Threshold values of 57 A.U. for microvascular flow and 13 A.U. for microvascular velocity were identified by an ROC analysis. This study, therefore, confirmed that impairment of microperfusion of the allograft cortex directly after reperfusion was a key indicator for the occurrence of DGF after kidney transplantation. Our results support the combined use of intraoperative duplex sonography, for macrovascular quality control, and quantitative microperfusion assessment, such as O2C spectrometry, for individual risk stratification to guide subsequent postoperative management.

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.

Grades of Below-the-Ankle Arterial Occlusive Disease following the Angiosome Perfusion: A New Morphological Assessment and Correlations with the Inframalleolar GVG Stratification in CLTI Patients

PURPOSE

To assess a specific classification of the foot atherosclerotic disease concerning the angiosomal source arteries, the connected foot arches and attached collaterals for Rutherford 5, CLTI patients. To compare eventual analogies of this novel grading system with previously reported GLASS/GVG inframalleolar patterns of occlusive disease (P0-P2).

MATERIALS AND METHODS

A series of 336 ischemic feet (221 diabetics) were selected and retrospectively analyzed. For each angiographic pattern of inframalleolar atherosclerotic disease, 4 severity classes of targeted angiosomal artery path (TAAP), associating 4 other classes concerning linked foot arches (LFA) and collaterals occlusive disease were described. By associating the 4 TAAP with the 4 others parallel LFA and collaterals classes, 4 novel anatomical "Grades" (A-D) of occlusive disease were described. Limb salvage was studied between groups of diabetic and non-diabetic patients.

RESULTS

Using a primary endovascular approach, limb preservation comparison of grade A/B proved without significance for diabetics (P = 0.032) and non-diabetics (P = 0.226). Comparison in diabetics and/or non-diabetics between A/C (P = 0.045 and 0.046), A/D (P = 0.027 and 0.030, B/C (P = 0.009 and 0.038), and B/D (P = 0.006 and P = 0.042), as well as C/D groups (P = 0.048 and P = 0.034) proved ponderous. Parallel analysis of similar grades (A/A, B/B, etc.) with, or without diabetes appeared without significance (P > 0.05). Further comparison between grades A+B (assigned as P0/GVG), versus C (P1), and D (P2), proved significant (P < 0.0001).

CONCLUSION

The present grading system proposes a useful correlation between the severity of foot angiosomal arteries, arches, and collaterals disease and limb salvage, confirming the clinical significance of P0-P2 GVG severity score. This analysis also points the limits of EVT to be probably avoided in grade D patients.

A Systematic Review and Critical Appraisal of Peri-Procedural Tissue Perfusion Techniques and their Clinical Value in Patients with Peripheral Arterial Disease

OBJECTIVE

Many techniques have been introduced to enable quantification of tissue perfusion in patients with peripheral arterial disease (PAD). Currently, none of these techniques is widely used to analyse real time tissue perfusion changes during endovascular or surgical revascularisation procedures. The aim of this systematic review was to provide an up to date overview of the peri-procedural applicability of currently available techniques, diagnostic accuracy of assessing tissue perfusion and the relationship with clinical outcomes.

DATA SOURCES

MEDLINE, Embase, CINAHL, and the Cochrane Central Register of Controlled Trials.

REVIEW METHODS

This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) guidelines. Four electronic databases were searched up to 31 12 2020 for eligible articles: MEDLINE, Embase, CINAHL and the Cochrane Central Register of Controlled Trials. Eligible articles describing a perfusion measurement technique, used in a peri-procedural setting before and within 24 hours after the revascularisation procedure, with the aim of determining the effect of intervention in patients with PAD, were assessed for inclusion. The QUADAS-2 tool was used to assess the risk of bias and applicability of the studies.

RESULTS

An overview of 10 techniques found in 26 eligible articles focused on study protocols, research goals, and clinical outcomes is provided. Non-invasive techniques included laser speckle contrast imaging, micro-lightguide spectrophotometry, magnetic resonance imaging perfusion, near infrared spectroscopy, skin perfusion pressure, and plantar thermography. Invasive techniques included two dimensional perfusion angiography, contrast enhanced ultrasound, computed tomography perfusion imaging, and indocyanine green angiography. The results of the 26 eligible studies, which were mostly of poor quality according to QUADAS-2, were without exception, not sufficient to substantiate implementation in daily clinical practice.

CONCLUSION

This systematic review provides an overview of 10 tissue perfusion assessment techniques for patients with PAD. It seems too early to appoint one of them as a reference standard. The scope of future research in this domain should therefore focus on clinical accuracy, reliability, and validation of the techniques.

The predictive value of microperfusion assessments for the follow-up of tibial bypass grafts

OBJECTIVE

We conducted a prospective evaluation of microperfusion parameters after tibial bypass surgery was performed. Differences between grafts with occlusions during follow-up and patent grafts were analyzed in relation to the pedal arch quality.

METHODS

Patients receiving tibial bypass grafts for chronic limb-threatening ischemia from 2019 to 2020 were included. Assessment of microcirculation (parameters: hemoglobin oxygen saturation [sO₂] and flow) was done by laser Doppler flowmetry and white light spectrometry (oxygen-to-see), supine and in elevation, whereas the macrocirculation was evaluated by the ankle-brachial index and duplex ultrasound examination. The quality of run-off was graded for each patient. Measurements were performed preoperatively, 1 day postoperatively, and after 6 months. Patients with graft occlusions during follow-up (OCCLUDED) and patients without occlusions (OPEN) were compared.

RESULTS

We included 42 patients (13 women, 29 men; mean age, 76.1 years; range, 60-89 years) were included. The patency of all grafts 1 day after the operation was confirmed by ultrasound examination. The overall analysis of the microcirculation showed significant changes in both the supine and elevated leg position between measurements taken preoperatively, 1 day after the operation, and after 6 months for the parameters sO₂ and FLOW (sO₂ supine, P = .001; sO₂ elevated, P < .001; FLOW supine, P < .001; FLOW elevated, P < .001). The comparison of the values 1 day after the operation yielded significantly decreased microperfusion parameters (both O₂ and FLOW) in the group that developed bypass occlusion in the later follow-up period (sO₂ supine: OCCLUDED, 35.7% [7.3-65.0] and OPEN, 48.7% [25.0-72.3] P = .011; FLOW supine: OCCLUDED, 27.7 A.U. [12.7-52.7] and OPEN, 57.3 A.U. [16.0-106.7], P = .008). No significant differences in the severity of the arch impairment was found between the OPEN and OCCLUDED groups (P = .651). Absolute values of the parameters sO₂ and flow showed no correlation with the pedal arch classification.

CONCLUSIONS

Significantly poorer microperfusion was detected postoperatively in patients with later occurrence of graft occlusions despite patent grafts on the first postoperative day. Microperfusion measurements might be a possible tool for the prediction of graft failure.

[Diabetic foot syndrome-Part 2 : Revascularization, treatment alternatives, care structures, recurrency prophylaxis]

Diabetic foot syndrome (DFS) is the most frequent reason for major amputations in Germany. The majority of foot lesions are triggered by repetitive pressure in diabetic polyneuropathy. Peripheral arterial occlusive disease (PAOD) impairs wound healing and is the main risk factor for amputations. The treatment of wounds and infections as well as timely revascularization are decisive. The use of endovascular and vascular surgical methods depends on the distribution pattern and length of the occlusion processes. Both procedures are complementary. Bypass surgery is of great importance for neuroischemic DFS. Multidisciplinary centers that provide revascularization in DFS can achieve an improvement of arterial blood flow in 90% of the cases and reduce the amputation rate by up to 80%. Due to the high recurrence rate of diabetic foot lesions, measures for secondary prophylaxis are of exceptional importance (podological and orthopedic technical care, foot surgery).

The Effect of Lower Limb Revascularization on Flow, Perfusion, and Systemic Endothelial Function: A Systematic Review

Peripheral arterial disease (PAD) is associated with reduced lower limb blood flow and tissue perfusion. The consequent reduction in vessel wall shear stress as well as ischemia-reperfusion injury has also been associated with systemic endothelial dysfunction and inflammation. We aimed to explore the impact of lower limb revascularization on (1) lower limb blood flow, (2) tissue perfusion, and (3) systemic endothelial function. We performed a systematic literature search using the MEDLINE, Embase, and Web of Science databases. Eligible studies measured changes in lower limb blood flow, perfusion, or systemic endothelial function following revascularization for the treatment of symptomatic PAD. We found 19 eligible studies, which were limited by considerable heterogeneity. Current evidence suggests that revascularization has a positive effect on flow, perfusion, and systemic endothelial dysfunction. Any changes may take a number of weeks to become apparent. There is a need for well-designed studies to explore the association between flow, perfusion, and endothelial dysfunction.

Infrapopliteal endovascular intervention and the angiosome concept: intraoperative real-time assessment of foot regions' blood volume guides and improves direct revascularization

OBJECTIVE

There is no consensus for determining which vessel should be revascularized in patients with multiple diseased infrapopliteal arteries. The angiosome concept may guide a more efficient targeted direct revascularization. Therefore, we conducted a study to assess whether the regional evaluation of foot blood volume may guide direct revascularization (DR) and if it will lead to better perfusion improvement than indirect revascularization (IR).

METHODS

We performed a prospective single-center observational cohort study in patients treated in the Department of Vascular Surgery of Peking Union Medical College Hospital from November 2016 to April 2019. Twenty-seven patients treated with endovascular intervention were included. The intraoperative parenchymal blood volume of different foot regions was obtained for each patient using C-arm CT before and after intervention.

RESULTS

The intervention procedure significantly increased the overall blood volume (48.95 versus 81.97 ml/1000 ml, p = 0.002). Patients with direct revascularization had a 197% blood volume increase while patients with indirect revascularization had a 39% increase (p = 0.028). The preoperative blood volume was higher in patients with mild symptoms than in patients with severe symptoms (58.20 versus 30.45 ml/1000 ml, p = 0.039). However, in regard to postoperative blood volume, no significant difference was discovered between these two groups (75.05 versus 95.01 ml/1000 ml, p = 0.275).

CONCLUSION

Based on quantitative measurements, we conclude that overall blood volume can rise significantly after the intervention. Revascularizing the supplying vessel of the ischemic area directly will result in better perfusion improvement than restoring blood supply through the collateral circulation. Preoperative blood volume is associated with preoperative symptoms.

KEY POINTS

• Flat panel detector CT can obtain intraoperative perfusion status and guide treatment in endovascular intervention. • Revascularizing the supplying vessel of the ischemic area directly will result in better perfusion improvement than restoring the blood supply through the collateral circulation. • Patients with severer clinical manifestations have lower blood volumes.

Foot Angiosomes: Instructions for Use

In the last 15 years an abundance of literature has demonstrated that angiosome-targeted revascularization, either endovascular or open, can lead to better clinical results in patients with chronic limb-threatening ischemia. According to this literature, the angiosome concept should guide our treatment strategy in every chronic limb-threatening ischemia patient. However, in our daily practice, its application is often difficult or impossible. Most foot wounds spread over multiple angiosomes and, moreover, the value of an angiosome-guided revascularization approach can vary according to vascular anatomy, collateral vessel network, type of revascularization, and wound. The aim of this article is to explore values and limits of the angiosome concept, and to propose some “instructions for use” regarding its application in our daily practice.

Wound closure by means of free flap and arteriovenous loop: Development of flap autonomy in the long-term follow-up

Free flaps in combination with arterial reconstruction by means of arteriovenous loops or bypass have, meanwhile, been established as a therapeutic option in defect reconstruction for areas without recipient vessels. Our aim was to analyse the long‐term performance, flap autonomy, and the flap perfusion. Patients receiving this combined reconstruction at a single‐centre institution were included. During follow‐up examination, the patency of arterial reconstruction was investigated by duplex ultrasound. Flap micro‐circulation was assessed by laser Doppler flowmetry and white light tissue spectrometry (O2C) as well as by indocyanine green fluorescence angiography. Twenty‐three patients could be clinically followed up. Duplex ultrasound showed, in four cases, arterial pedicle occlusion in spite of vital flap. Comparison of the O2C perfusion parameters between flaps with occluded pedicles and those with intact inflow showed no significant difference (parameters sO2: P = .82; Flow: P = .31). Similar results were obtained by fluorescence angiography; no significant difference could be detected between both groups (parameters Ingress P = .13; Ingressrate P = .54). Combined vascular reconstruction with free tissue transfer is associated with a good long‐term outcome and wound closure. Even after flap transplantation to areas with critical tissue perfusion, the flap can develop autonomy and thus survive after pedicle occlusion.

Editor's Choice - Impact of Endovascular Pedal Artery Revascularisation on Wound Healing in Patients With Critical Limb Ischaemia

OBJECTIVE

The present study investigated the impact of endovascular pedal artery revascularisation (PAR) on the clinical outcomes of patients with critical limb ischaemia (CLI).

METHODS

This retrospective analysis of a single centre cohort included 239 patients who underwent endovascular revascularisation of infrapopliteal arteries for a chronic ischaemic wound. PAR was attempted in 141 patients during the procedure. After propensity score matching, there were 87 pairs of patients with and without PAR.

RESULTS

After the matching, the two groups showed balanced baseline clinical and lesion characteristics. PAR was achieved in 60.9% of the PAR group. Direct angiosome flow was more frequently obtained in the PAR group than in the non-PAR group (81.6% vs. 34.5%; p < .001). Subintimal angioplasty (47.1% vs. 29.9%; p = .019) and pedal-plantar loop technique (18.4% vs. 0%; p < .001) were more frequent in the PAR group. At the one year follow up, the PAR group showed greater freedom from major amputation (96.3% vs. 84.2%; p = .009). The wound healing rate, overall survival, major adverse limb event, and freedom from re-intervention did not differ significantly between the two groups. However, the patient subgroup with successful PAR showed a higher wound healing rate than the non-PAR group (76.0% vs. 67.0%; p = .031). In a multivariable Cox proportional hazards regression model, successful PAR (hazard ratio [HR] 1.564, 95% confidence interval [CI] 1.068-2.290; p = .022) was identified as an independent factor associated with improved wound healing, whereas gangrene (HR 0.659, 95% confidence interval [CI] 0.471-0.923; p = .015), C reactive protein >3 mg/dL (HR 0.591, 95% CI 0.386-0.904; p = .015), and pre-procedural absence of pedal arch (HR 0.628, 95% CI 0.431-0.916; p = .016) were associated with impaired wound healing.

CONCLUSION

Successful PAR significantly improved wound healing in patients with CLI. Thus, efforts should be made to revascularise the pedal arteries, especially when the pedal arch is completely absent.

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

The angiosome concept of foot perfusion was conceived based on anatomical studies of arterial circulation and used for planning surgical procedures, tissue reconstruction, and amputation. Its application is relevant in diabetic patients with critical limb ischemia and nonhealing foot ulcer or amputation. An understanding of foot angiosome anatomy is useful for predicting healing and planning arterial revascularization. A review of the literature, including the most recent systematic reviews and meta-analyses, indicates improved wound healing is achieved when the angiosome concept is followed. The greatest value of angiosome-based revascularization is in patients with lesion(s) limited to a single angiosome, or to achieve optimal healing of amputation sites. Future research should focus on proper identification of (imaging) modalities to determine the hemodynamic and functional changes before and after revascularization, thus identifying the "real" angiosome and directing optimal therapy.

Angiosome Specific Revascularisation: Does the Evidence Support It?

OBJECTIVE

To explain the angiosome concept and explore the practical application of the angiosome literature to a clinical scenario, in this case a tibial angioplasty for critical ischaemia.

METHODS

Clinical vignette with explanation of the decisions made and subsequent clinical results based on the theory of the angiosome concept and the literature on angiosomal revascularisation; in this case the results of our group's recent update to a systematic review and meta-analysis.

RESULTS

Endovascular combined or direct angiosomal revascularisation if superior to indirect revascularisation. This was borne out in the clinical scenario, where an indirect peroneal reperfusion of the AT angiosome resulted in major amputation. Open surgery is less dependent on the angiosome concept. The presence of adequate collateralisation into a foot arch seems to be the most important factor predicting success of indirect revascularisation. The evidence for both suffers from selection bias and many of the findings in the literature are wholly due to selection bias.

CONCLUSION

The angiosome concept is useful during both open and endovascular tibial revascularisation. However, the runoff in the foot is critical to success and may not follow the 'classic' angiosome model in diabetes.

Contemporary critical limb ischemia: Asian multidisciplinary consensus statement on the collaboration between endovascular therapy and wound care

The burden of peripheral artery disease (PAD) and diabetes in Asia is projected to increase. Asia also has the highest incidence and prevalence of end-stage renal disease (ESRD) in the world. Therefore, most Asian patients with PAD might have diabetic PAD or ESRD-related PAD. Given these pandemic conditions, critical limb ischemia (CLI) with diabetes or ESRD, the most advanced and challenging subset of PAD, is an emerging public health issue in Asian countries. Given that diabetic and ESRD-related CLI have complex pathophysiology that involve arterial insufficiency, bacterial infection, neuropathy, and foot deformity, a coordinated approach that involves endovascular therapy and wound care is vital. Recently, there is increasing interaction among cardiologists, vascular surgeons, radiologists, orthopedic surgeons, and plastic surgeons beyond specialty and country boundaries in Asia. This article is intended to share practical Asian multidisciplinary consensus statement on the collaboration between endovascular therapy and wound care for CLI.

Noninvasive measurements of tissue perfusion in critical limb ischemia

Critical limb ischemia (CLI) remains a challenge for an interdisciplinary therapeutic team due to chronic nonhealing wounds. Against this background, there is a necessity of quality control after revascularization. Beside the isolated evaluation of the macrocirculation by Ankle-Brachial or Toe-Brachial Index measurements, the microcirculation as an additional important factor of wound healing often remains underestimated. The following article gives an overview about the current investigation methods for noninvasive perfusion control of the CLI patient. Therefore, transcutaneous oxygen pressure (tcpO₂), the “oxygen-to-see” method which is a combination of white light tissue spectrometry and laser-Doppler flowmetry, fluorescence angiography with indocyanine green, and multispectral optoacoustic tomography will be described.

Pilot Assessment of the Angiosome Concept by Intra-operative Fluorescence Angiography After Tibial Bypass Surgery

OBJECTIVES

The "angiosome" concept as a model for decision making in revascularisation of patients with critical limb ischaemia (CLI) has been subject to lively discussion in recent years. The aim of this prospective pilot study was to use intra-operative fluorescence angiography to provide further data on the angiosome concept on the level of microcirculation after tibial bypass surgery.

DESIGN, MATERIALS, AND METHODS

This was a prospective analysis of 40 patients presenting with CLI Rutherford stage IV to VI before and after tibial bypass surgery. The macrocirculation was measured by the ankle brachial index. Skin microcirculation was assessed by intra-operative fluorescence angiography. The alteration of microcirculation was compared in direct and indirect revascularised angiosomes. Clinical follow-up investigations were performed and the wound healing rate was compared between the different revascularisation methods.

RESULTS

Cumulated microcirculation parameters showed a significant improvement after surgery (ingress, ingress rate p<.001). Likewise, general microcirculatory improvement was observed in each foot angiosome after revascularisation, regardless of the tibial artery revascularised. Furthermore, a comparison of the direct (DR) and the indirect revascularised (IR) angiosomes did not show a significant difference concerning the improvement of microcirculation (difference DR-IR, ingress: 1.69, 95% CI 71.73-75.11; ingress rate: 0.08, 95% CI -12.91 to 13.07). The wound healing rate was similar in both groups, although the time to wound healing was faster by on average 2.5 months in the DR group (p=.083).

CONCLUSION

Microcirculatory improvement was seen over the whole foot after tibial bypass. Therefore, fluorescence angiography is a promising tool to evaluate the angiosome concept in future larger studies. Clinicaltrials.gov: NCT03012750.

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.