Primary infragenicular angioplasty for diabetic neuroischemic foot ulcers following the angiosome distribution: a new paradigm for the vascular interventionist?

Comparative Outcomes of Targeted versus Non-Targeted Angiosome Revascularization for Diabetic Foot Wounds Impact of Target Arterial Path on Wound Healing

INTRODUCTION

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.

MATERIALS AND 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 GLASS 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 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).

CONCLUSION

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

Peripheral Blood Mononuclear Cells: A New Frontier in the Management of Patients with Diabetes and No-Option Critical Limb Ischaemia

The current study aimed to evaluate the effectiveness of peripheral blood mononuclear cell (PB-MNC) therapy as adjuvant treatment for patients with diabetic foot ulcers (DFUs) and no-option critical limb ischaemia (NO-CLI). The study is a prospective, noncontrolled, observational study including patients with neuro-ischaemic DFUs and NO-CLI who had unsuccessful revascularization below the ankle (BTA) and persistence of foot ischaemia defined by TcPO2 values less than 30 mmHg. All patients received three cycles of PB-MNC therapy administered through a "below-the-ankle approach" in the affected foot along the wound-related artery according to the angiosome theory. The primary outcome measures were healing, major amputation, and survival after 1 year of follow-up. The secondary outcome measures were the evaluation of tissue perfusion by TcPO2 and foot pain defined by the numerical rating scale (NRS). Fifty-five patients were included. They were aged >70 years old and the majority were male and affected by type 2 diabetes with a long diabetes duration (>20 years); the majority of DFUs were infected and nearly 90% were assessed as gangrene. Overall, 69.1% of patients healed and survived, 3.6% healed and deceased, 10.9% did not heal and deceased, and 16.4% had a major amputation. At baseline and after PB-MNC therapy, the TcPO2 values were 17 ± 11 and 41 ± 12 mmHg, respectively (p < 0.0001), while the pain values (NRS) were 6.8 ± 1.7 vs. 2.8 ± 1.7, respectively (p < 0.0001). Any adverse event was recorded during the PB-MNC therapy. Adjuvant PB-MNC therapy seems to promote good outcomes in patients with NO-CLI and neuro-ischaemic DFUs.

An angiosome-centred approach for TcpO2 electrode positioning

Background: The latest guidelines propose a TcpO2 value of 30 mmHg to help to confirm the diagnosis of chronic limb threatening ischemia. However, placement of electrodes is not standardised. The relevance of an "angiosome-centred" approach for TcpO2 electrode positioning has never been evaluated. We therefore retrospectively analysed our TcpO2 results to study the impact of electrode placement on the different angiosomes of the foot. Patients and methods: Patients consulting the vascular medicine department laboratory for suspicion of CLTI using TcpO2 electrodes placement on the different angiosome arteries of the foot (first inter metatarsal space, lateral edge of the foot and plantar side of the foot) were included. As the mean intra-individual variation is reported to be 8 mmHg, a variation of mean TcpO2 for the 3 locations ≤8 mmHg was considered to be not clinically significant. Results: Thirty-four patients (34 ischemic legs) were analysed. The mean TcpO2 was higher at the lateral edge of the foot (55 mmHg) and plantar side of the foot (65 mmHg) than at the first intermetatarsal space (48 mmHg). There was no clinically significant variation of mean TcpO2 according to anterior/posterior tibial artery patency and fibular artery patency. This was present when stratifying on the number of patent arteries. Conclusions: The present study suggests that multi-electrode TcpO2 is not useful to assess tissue oxygenation in the different angiosomes of the foot to guide surgical decision; first intermetatarsal electrode alone would be preferred. TcpO2 seems rather to evaluate overall tissue oxygenation of the foot. Electrode location on the plantar side of the foot may overestimate results and lead to misinterpretation.

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.

CT perfusion in peripheral arterial disease-hemodynamic differences before and after revascularisation

Objectives

The purpose of this study was the assessment of volumetric CT perfusion (CTP) of the lower leg musculature in patients with symptomatic peripheral arterial disease (PAD) before and after interventional revascularisation.

Methods

Twenty-nine consecutive patients with symptomatic PAD of the lower extremities requiring interventional revascularisation were assessed prospectively. All patients underwent a CTP scan of the lower leg, and hemodynamic and angiographic assessment, before and after intervention. Ankle-brachial pressure index (ABI) was determined. CTP parameters were calculated with a perfusion software, acting on a no outflow assumption. A sequential two-compartment model was used. Differences in CTP parameters were assessed with non-parametric tests.

Results

The cohort consisted of 24 subjects with an occlusion, and five with a high-grade stenosis. The mean blood flow before/after (BFpre and BFpost, respectively) was 7.42 ± 2.66 and 10.95 ± 6.64 ml/100 ml*min⁻¹. The mean blood volume before/after (BVpre and BVpost, respectively) was 0.71 ± 0.35 and 1.25 ± 1.07 ml/100 ml. BFpost and BVpost were significantly higher than BFpre and BVpre in the treated limb (p = 0.003 and 0.02, respectively), but not in the untreated limb (p = 0.641 and 0.719, respectively).

Conclusions

CTP seems feasible for assessing hemodynamic differences in calf muscles before and after revascularisation in patients with symptomatic PAD. We could show that CTP parameters BF and BV are significantly increased after revascularisation of the symptomatic limb. In the future, this quantitative method might serve as a non-invasive method for surveillance and therapy control of patients with peripheral arterial disease.

Key Points

• CTP imaging of the lower limb in patients with symptomatic PAD seems feasible for assessing hemodynamic differences before and after revascularisation in PAD patients.

• This quantitative method might serve as a non-invasive method, for surveillance and therapy control of patients with PAD.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-07692-5.

NMR-based metabolomic analysis for the effects of Huiyang Shengji extract on rat diabetic skin ulcers

ETHNOPHARMACOLOGICAL RELEVANCE

Huiyang Shengji formula (HSF) is a compound Chinese herbal medicine prescription, and has long been used for treating chronic non-healing wounds.

AIM OF THE STUDY

The purpose of this study was to provide new insight into molecular mechanisms of healing effects of the HSF treatments.

MATERIALS AND METHODS

We established a rat diabetic skin ulcer (DSU) model, and assessed healing effects of four HSF treatments on DSUs by calculating wound healing rates and immunohistochemical detection of the expressions of angiogenesis-related factors in the model rats (Mod) relative to normal rats (Nor), including Huiyang extract (HE), Shengji extract (SE), Huiyang Shengji extract (HSE) and HSE associated with acupuncture (Ac-HSE). We then performed NMR-based metabolomic analyses on skin tissues of the Nor, Mod, HSE-treated, Ac-HSE-treated rats to address metabolic mechanisms underlying these effects.

RESULTS

These treatments up-regulated expressions of two angiogenesis-related factors VEGF and CD31, and improved efficacy of healing DSUs, in which HSE and Ac-HSE exhibited the most significant effects. Compared with Mod, HSE and Ac-HSE groups shared four characteristic metabolites (lactate, histidine, succinate and acetate) and four significantly altered metabolic pathways with Nor. Both HSE and Ac-HSE treatments could partly reverse the metabolically disordered pathological state of DSUs to the normal state. They might improve wound healing through promoting glucose metabolism, BCAAs metabolism, and enhancing antioxidant capacity and angiogenesis in DSU tissues. Ac-HSE significantly enhanced wound healing rates compared to HSE, potentially owing to significant capacities of enhancing anti-oxidation and angiogenesis and interfering three more metabolic pathways.

CONCLUSIONS

This work provides a mechanistic understanding of the healing effects of the HSE and Ac-HSE treatments on DSUs, is of benefit to improvements of the HSF treatments for clinically healing chronic non-healing wounds.

Low frequency oscillations assessed by diffuse speckle contrast analysis for foot angiosome concept

An angiosome refers to a 3D tissue volume that is vascularized by a single artery and is a relatively new concept that is useful in vascular surgery; however, the direct relationship between arterial blood flow and micro-perfusion is still controversial. Here, we propose a diffuse speckle contrast analysis (DSCA), which is an emerging tissue perfusion monitoring modality, to investigate the correlations among low frequency oscillations (LFOs) measured from different areas on the feet of healthy subjects. We obtained reproducible results from the correlation analyses of LFOs, and their physiological implications were discussed. In order to confirm the changes in the frequency oscillations, we analyzed and compared the power spectral density changes due to heart rate variability in the electrocardiographic signal during reactive hyperemia and head-up tilt protocols.

Dynamic Volume Perfusion CT of the Foot in Critical Limb Ischemia: Response to Percutaneous Revascularization

OBJECTIVE. The purpose of this study was to assess the reproducibility and validity of quantitative perfusion parameters derived from dynamic volume perfusion CT in patients with critical limb ischemia (CLI) and to evaluate perfusion parameter changes before and after endovascular revascularization. SUBJECTS AND METHODS. Patients with CLI referred for unilateral extremity endovascular arterial recanalization were enrolled in this study. CT examinations obtained 1-3 days before the procedure and then within 1 week after the treatment were evaluated at two reading sessions. Blood flow (BF), blood volume (BV), and time to peak (TTP) were measured on color-coded maps and compared statistically. Intraobserver agreement was assessed using intraclass correlation coefficient (ICC) and Bland-Altman analysis. RESULTS. Endovascular treatment was technically successful for all 16 patients. The posttreatment BF and BV showed a statistically significant increase in both dermal and muscle areas (p < 0.05). The posttreatment TTP shortened at a statistically significant level (p < 0.05). In the 3-month clinical follow-up period, the limb salvage rate was 81% and the percentage change in BF and BV of patients with poor response to treatment had no statistically significant increase after treatment, consistent with the clinical assessment. The percentage change in BF and BV correlated well with the improvement of the clinical condition (r = 0.673-0.901). ICC values showed excellent agreement in the range of 0.95-0.98. CONCLUSION. As a reproducible method, dynamic volume perfusion CT of the foot may enable quantitative evaluation of the perfusion of soft tissues and also provide a novel approach to assessing response to endovascular recanalization in CLI.

Endovascular treatment of diabetic foot ischemic ulcer - Technical review

This article is a technical review of the common techniques used in the treatment of lower-limb occlusive arterial disease associated with diabetes. The techniques described here reflect the author’s own practice and are methods that the author finds helpful in avoiding complications and in making the technical aspects of the procedures easier.

On the Origin of Intraoperative Pressure Injury: An Angiosomal Theory of Pressure Injury Formation

We review a case of a 22-year-old healthy man who underwent a 5-h maxillofacial surgery while continuously supine with foam pads placed prophylactically over elevated heels. Immediately after surgery, Stage 1 pressure injuries appeared on the left lateral heel and right lateral ankle, despite the absence of local pressure to these areas. Both lesions eventually resolved. Eight months later, a Doppler evaluation was performed of the patient's lower extremities, the peroneal artery and its tributaries were marked, and the intraoperative positioning was simulated to determine if a wedge at the back of the calf could have obstructed blood flow in these vessels. In this position, the feet naturally abducted so that the lateral calcaneal and posterior malleolar arteries became positioned immediately underneath the wedge. We propose a vascular mechanism of pressure injury development, postulating that some heel pressure injuries are not the result of localized pressure but rather angiosomal ischemia, based on the observation that the anatomical pattern of these lesions frequently follow the distribution of a named vessel. We hypothesize that in this case, intraoperative positioning along with permissive hypotension may have occluded arterial or venous flow to the relevant angiosomes, causing an ischemia reperfusion injury to the downstream tissues.

CT-perfusion in peripheral arterial disease - Correlation with angiographic and hemodynamic parameters

Objective

The purpose of this study was the assessment of volumetric CT-perfusion (CTP) of the lower leg musculature in patients with symptomatic peripheral arterial disease (PAD) of the lower extremities, comparing it with established angiographic and hemodynamic parameters.

Materials and methods

Thirty-five consecutive patients with symptomatic PAD of the lower extremities requiring interventional revascularization were assessed prospectively. All patients underwent a CTP scan of the lower leg, and hemodynamic and angiographic assessment. Hemodynamic parameters, specifically ankle-brachial pressure index (ABI), ankle blood pressure (ABP), peak systolic velocity (PSV), and segmental pulse oscillography (SPO) level, were determined. Lesion length and degree of collateralization were assessed by interventional angiography. CTP parameters were calculated with a perfusion software, acting on a no outflow assumption. A sequential two-compartment model was used. Differences in CTP parameters and correlations between CTP, hemodynamic and angiographic parameters were assessed with non-parametric tests.

Results

The cohort consisted of 27 subjects with an occlusion, and eight with a high-grade stenosis. The mean blood flow (BF) was 7.71 ± 2.96 ml/100ml*min^-1, mean blood volume (BV) 0.71 ± 0.33 ml/100ml, and mean mean transit time (MTT) 7.22 ± 2.66 s. BF and BV were higher in subjects with longer lesions, and BV was higher in subjects with lower ABI. Significant correlations were found between lesion length and BV (r = 0.65) and BF (r = 0.52). Significant inverse correlations were found between BV and ABI and between BV and ABP (r = -0.56, for both correlations).

Conclusions

In our study, we have shown the feasibility of CTP for the assessment of PAD. In the future, this quantitative method might serve as a non-invasive method, possibly complementing the diagnostic workup of patients with peripheral arterial disease.

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 based time series analysis of deep tissue perfusion using diffuse speckle contrast analysis

An angiosome is a three dimensional volume of biological tissue which a specific artery governs. Although proven useful for vascular surgery, the direct relationship between arterial flow and microcirculation in specific angiosome remains controversial. Here, we present new optical approach, a four-channel diffuse speckle contrast analysis (DSCA) which can simultaneously measure blood perfusion at different foot area. Based on the hypothesis that same angiosome will support similar low frequency oscillation, we investigated cross-correlation among different DSCA channels. Our preliminary results show that the LFO signal from the channel closest to posterior tibial artery is leading the signal from the other channels.

Is Angiosome-Targeted Angioplasty Effective for Limb Salvage and Wound Healing in Diabetic Foot? : A Meta-Analysis

PURPOSE

Given that the efficacy of employing angiosome-targeted angioplasty in the treatment of diabetic foot remains controversial, this study was conducted to examine its efficacy.

METHODS

We performed a systematic literature review and meta-analysis using core databases, extracting the treatment modality of angiosome-targeted angioplasty as the predictor variable, and limb salvage, wound healing, and revision rate as the outcome variables. We used the Newcastle-Ottawa Scale to assess the study quality, along with the Cochrane Risk of Bias Tool. We evaluated publication bias using a funnel plot.

RESULTS

The search strategy identified 518 publications. After screening these, we selected four articles for review. The meta-analysis revealed that overall limb salvage and wound healing rates were significantly higher (Odds ratio = 2.209, 3.290, p = 0.001, p<0.001) in patients who received angiosome-targeted angioplasty than in those who received nonangiosome-targeted angioplasty. The revision rate between the angiosome and nonangiosome groups was not significantly different (Odds ratio = 0.747, p = 0.314).

CONCLUSION

Although a further randomized controlled trial is required for confirmation, angiosome-targeted angioplasty in diabetic foot was more effective than nonangiosome-targeted angioplasty with respect to wound healing and limb salvage.

[Long-term results after balloon angioplasty of crural arteries. Which factors influence leg salvage and survival rates?]

AIM

Clinical and statistical study analysing factors with influence on success rates, procedure-related complications, and long-term results for patients who underwent angioplasty of the crural arteries.

MATERIAL AND METHODS

Retrospectively we evaluated all patients who underwent angioplasty of the crural arteries due to critical chronic limb ischemia or severe claudication in the time period from 1/2002 to 12/2005. These patients were contacted in the time period from 1/2009 to 12/2010, and a follow-up examination including angiography was performed or telephone interviews were conducted with patients, relatives and referring physicians for follow-up. 212 patients with a mean age of 77.8 years (99 women and 113 men) underwent crural angioplasty on 239 limbs. The primary end points were the limb salvage rate and patient survival rate. The secondary end points included the complication rate, technical success rate, and patency rate. The prognostic relevance of treatment and selected variables with respect to limb salvage and patient survival were analysed with multiple logistic regression.

RESULTS

The technical success rate was 98.4%. Between 1/2009 and 12/2010, 49.5% of the patients died. An angiographic follow-up study was performed in 49.9% of the treated legs. The primary patency-rate (72% after 6 months and 62.8% after 12 months) was significant, influenced only by the riskfactor dialysis (p = 0.0207). After a mean follow-up of 3.7 years, 48 patients (22.6%) experienced minor- or major-amputation on 53 legs (22.2%). The limb salvage rate (Kaplan-Maier estimation) was 85.4% after 5 years. The mean survival rate according to Kaplan-Meier was 79.7, 72.2, 67.3 and 51.4% after 1, 2, 3 and 5 years, respectively. Results of multiple logistic regression analysis showed that negative prognostic variables with respect to patient survival were amputation (p = 0.0017) and dialysis (p = 0.0011) and with respect to limb salvage dialysis (p < 0.0001) and non-patent peroneal artery (p < 0.0001).

CONCLUSION

Balloon angioplasty of the crural arteries shows a high technical success rate with an acceptable complication rate. Dialysis and non-patent peroneal artery are negative prognostic variables for the clinical long-term success.

The Feasibility of Angiosome-Targeted Endovascular Treatment in Patients with Critical Limb Ischemia and Foot Ulcer

BACKGROUND

To determine wound location according to the angiosome concept and to investigate the feasibility and success of angiosome-based revascularization in below-the-knee (BTK) arteries.

METHODS

This was a retrospective study of 161 patients (67.5 ± 25.5 years, 66.5% diabetics) with critical limb ischemia and a foot ulcer, stage Rutherford 5-6, who underwent percutaneous transluminal angioplasty on BTK arteries in 2012. We evaluated feasibility of angiosome-targeted revascularization and the number of angiosomes affected by a wound in each patient. Patients were divided into 3 groups depending on how many BTK vessels were suitable for revascularization. The feasibility was analyzed in each group and in relation to number of affected angiosomes.

RESULTS

The wound(s) interfered with one angiosome in only 39 (24.0%) cases. Direct flow into affected angiosome was successfully achieved in 98 (60.9%) cases. If ulceration was limited in one angiosome, the targeted revascularisation was possible in 27 cases (69.2%), if ulceration was extended over 2 angiosomes it was possible in 65 cases (86.7%), if 3 angiosomes were affected it was possible in 36 cases (85.7%), when 4 angiosomes were affected the rate dropped to 25.0% and ulceration extended over 5 angiosomes had no possibility of revascularization.

CONCLUSIONS

In critical limb ischemia, the tissue lesion affects several angiosomes in majority of the cases. In thus far published literature, there is existence of more approaches of angiosome-targeted revascularization when more than one angiosome is clinically involved and therefore consensus needs to be achieved for the accurate definition.

Diabetic foot infections: state-of-the-art

Foot infections are frequent and potentially devastating complications of diabetes. Unchecked, infection can progress contiguously to involve the deeper soft tissues and ultimately the bone. Foot ulcers in people with diabetes are most often the consequence of one or more of the following: peripheral sensory neuropathy, motor neuropathy and gait disorders, peripheral arterial insufficiency or immunological impairments. Infection develops in over half of foot ulcers and is the factor that most often leads to lower extremity amputation. These amputations are associated with substantial morbidity, reduced quality of life and major financial costs. Most infections can be successfully treated with optimal wound care, antibiotic therapy and surgical procedures. Employing evidence-based guidelines, multidisciplinary teams and institution-specific clinical pathways provides the best approach to guide clinicians through this multifaceted problem. All clinicians regularly seeing people with diabetes should have an understanding of how to prevent, diagnose and treat foot infections, which requires familiarity with the pathophysiology of the problem and the literature supporting currently recommended care.

Results of infrapopliteal endovascular procedures performed in diabetic patients with critical limb ischemia and tissue loss from the perspective of an angiosome-oriented revascularization strategy

Our aim was to describe our experience with infrapopliteal endovascular procedures performed in diabetic patients with ischemic ulcers and critical ischemia (CLI). A retrospective study of 101 procedures was performed. Our cohort was divided into groups according to the number of tibial vessels attempted and the number of patent tibial vessels achieved to the foot. An angiosome anatomical classification of ulcers were used to describe the local perfusion obtained after revascularization. Ischemic ulcer healing and limb salvage rates were measured. Ischemic ulcer healing at 12 months and limb salvage at 24 months was similar between a single revascularization and multiple revascularization attempts. The group in whom none patent tibial vessel to the foot was obtained presented lower healing and limb salvage rates. No differences were observed between obtaining a single patent tibial vessel versus more than one tibial vessel. Indirect revascularization of the ulcer through arterial-arterial connections provided similar results than those obtained after direct revascularization via its specific angiosome tibial artery. Our results suggest that, in CLI diabetic patients with ischemic ulcers that undergo infrapopliteal endovascular procedures, better results are expected if at least one patent vessel is obtained and flow is restored to the local ischemic area of the foot.

An en bloc approach to CT perfusion for the evaluation of limb ischemia

We examine volumetric CT perfusion in soft tissues of the entire foot with an en bloc technique to provide a meaningful measure of differentiation between mild and major vascular impairment. With Institutional Review Board approval, 22 healthy male subjects between the ages of 21 and 50 (mean 37) were enrolled. Volumetric computed tomography using an en bloc technique was conducted on 14 subjects for validation while unilateral vascular obstruction was simulated in the calves of the remaining 8 subjects. Perfusion estimates were made using in-house software and differences in perfusion estimates between feet were evaluated with Student's t-test at 95% confidence. Subjects with simulated major vascular obstruction (calf blood pressure cuff inflated to 200 mmHg) showed significantly higher ratios of perfusion estimates between the unobstructed and obstructed foot compared to subjects with simulated mild vascular obstruction (cuff inflated to 120 mmHg), mean 4.6, SD 2.6 vs. mean 1.3, SD 0.2; P = 0.05. CT perfusion using an en bloc technique shows promise for the future evaluation of patients with critical limb ischemia and particularly for re-characterization post medical, surgical or endovascular intervention.

Endovascular treatment of critical ischemia in the diabetic foot: new thresholds, new anatomies

This review discusses the role of endovascular treatment in diabetic patients with critical limb ischemia (CLI). Angioplasty of the femoropopliteal region achieves similar technical success and limb salvage rates in diabetic and nondiabetic patients. Angioplasty in as many as possible tibial vessels is accompanied by more complete and faster ulcer healing as well as better limb salvage rates compared to isolated tibial angioplasty. Targeted revascularization of a specific vessel responsible for the perfusion of a specific ulcerated area is a promising new approach: it replaces revascularization of the angiographically easiest-to-access tibial vessel, even if this is not directly responsible for the perfusion of the ulcerated area, by revascularization of area-specific vascular territories. In conclusion, the endovascular approach shows very high efficacy in ulcer healing for diabetic patients with CLI. Larger prospective studies are now needed to estimate the long-term results of this approach.