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

Current opinion on the role of the foot perfusion in limb amputation risk assessment

The most important and consulted guidelines dealing with not healing foot ulcers suggest the measurement of the foot perfusion (FP) to exclude the critical limb ischemia (CLI), because of the high risk of limb amputation. But the recommended cut-off values of FP fail to include all the heterogeneity of patients of the real-life with a not healing ulcer. Often these patients are diabetics with a moderate PAD but with a high level of infection. To meet this goal, in 2014, the Society for Vascular Surgery has published the "Lower Extremity Threatened Limb Classification System: Risk stratification based on Wound, Infection, and foot Ischemia (WIfI)." This new classification system has changed the criteria of assessment of limb amputation risk, replacing the single cut-off value role with a combination of a spectrum of perfusion values along with graded infection and dimension levels of skin ulcers. The impact of this new classification system was remarkable so to propose the substitution of the CLI definition, with the new Critical limb-threatening ischemia (CLTI), that seems to define the limb amputation risk more realistically.

Thermographic Characteristics of the Diabetic Foot With Peripheral Arterial Disease Using the Angiosome Concept

AIM

To compare temperature changes following a challenge of limb elevation, in 3 forefoot angiosomes between type 2 diabetes mellitus patients with and without peripheral arterial disease (PAD).

METHODS

Participans were categorized in a no PAD, mild PAD or severe PAD group. All underwent thermal imaging, then successive thermal images were taken at 1 min intervals after the lower limbs were elevated for 5 min. Thereafter, the lower limbs were lowered to the original position and imaged after 1 min. Mean temperatures of the hallux, medial and lateral forefoot were analysed by the angiosome concept.

RESULTS

Forty-two limbs were analysed. Mean resting temperatures of all angiosomes of participants with PAD were higher than those with no peripheral arterial disease. A significant difference in the mean initial temperature between the groups was found in the medial and lateral forefoot angiosomes (p=0.048, p=0.049 respectively), whilst at the hallux these temperatures were not significant (p=0.165). After limb elevation, the only significant difference was seen in the lateral foot area at 1 min (p=0.021).

CONCLUSIONS

These results confirm that patients with PAD exhibit significantly higher forefoot temperatures, according to the angiosome concept. The challenge by foot elevation did not affect the thermal pattern significantly.

Hyperbaric Oxygen Therapy in Ischaemic Foot Ulcers in Type 2 Diabetes: A Clinical Trial

Background and Aims:

Several treatment modalities and protocols for ischaemic foot ulcers are available. However, little consensus exists on optimal treatment. The aim of this study was to compare Standard Wound Care (SWC) alone vs. SWC with adjunct hyperbaric oxygen therapy (HBOT) in the treatment of ischaemic Diabetic Foot Ulcers (DFUs).

Patients and Methods:

Twenty-six patients with Type 2 Diabetes Mellitus (T2DM) presenting with a newly diagnosed ischaemic foot ulcer were included. These were divided into group A (SWC with adjunct HBOT) and group B (SWC only). Participants were followed every week for 4 weeks and their ulcers were measured for their surface area and depth to assess any change in wound size.

Results:

Both treatment arms succeeded in reducing ulcer area and depth (p<0.001). However, ulcer area (p<0.001) and depth (p<0.001) exhibited superior improvement in group A.

Conclusion :

Adjunctive HBOT appears to improve wound healing in ischaemic DFUs and merits further study.

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.

Evidence based review of literature on detriments to healing of diabetic foot ulcers

BACKGROUND

Diabetes mellitus places a substantial burden on society worldwide. Diabetic foot ulcers are a challenging problem for clinicians. Seven generally accepted detriments to healing of diabetic foot ulcers were identified: infection, glycaemic control, vascular supply, smoking, nutrition, deformity and offloading. The aim of this paper is to present a comprehensive evidence based review of the literature available on detriments to healing of diabetic foot ulcers.

METHOD

A research question was generated for each of the detriments to healing and a comprehensive review of the literature was performed using the Pubmed database in July 2014. All articles were assessed for relevancy and a level of evidence was assigned. An analysis of the total body of literature was used to assign a grade of recommendation to each detriment.

RESULTS

Grade A recommendation was assigned to offloading as there was good evidence supporting this intervention. Grade B recommendation was assigned to deformity as there was fair evidence consistent with the hypothesis. Infection and vascular supply had poor quality evidence supporting the research question and grade C recommendation was assigned. Grade I recommendation was assigned to glycaemic control, smoking and nutrition as there was insufficient and conflicting evidence available.

CONCLUSION

Our literature review revealed good evidence for some factors and insufficient literature on others. Further studies are needed to provide quality evidence regarding detriments to healing of diabetic ulcers.

Efficacy of a New Heparan Sulfate Mimetic Dressing in the Healing of Foot and Lower Extremity Ulcerations in Type 2 Diabetes: A Case Series

A novel heparan sulfate glycosaminoglycan mimetic product for local application to promote wound healing (CACIPLIQ) has recently become available. It is a biophysical therapeutic product comprising a polysaccharide as an innovative biomaterial to accomplish mechanical tissue engineering and skin regeneration in the site of ulceration. We present a series of 12 patients with type 2 diabetes (4 men and 8 women; age 53-87 years; diabetes duration 8-25 years) having chronic resistance to therapy for foot and lower extremity ulcerations. CACIPLIQ was locally applied twice per week after careful debridement. Complete ulcer healing was accomplished in all patients after a mean treatment duration of 4.92 months (range = 2-12 months). The product was very well tolerated. In conclusion, these results, although preliminary, are encouraging and suggest adequate efficacy and safety of the new product in difficult-to-heal foot and lower extremity ulcerations in type 2 diabetes.

The Angiosome Concept Evaluated on the Basis of Microperfusion in Critical Limb Ischemia Patients-an Oxygen to See Guided Study

OBJECTIVES

Aim of this clinical study was to evaluate the angiosome concept with regard to the microcirculation of the foot in patients with CLI and to evaluate its relevance by means of combined laser Doppler flowmetrie and white-light tissue spectrophotometry.

METHODS

Twenty-eight patients who underwent leg revascularization in the stage of CLI were prospectively examined. The microperfusion was assessed by light guided spectrophotometry. The measuring points were set according to the angiosome concept into direct and indirect revascularized areas of the foot. Investigations were performed pre and postinterventionally and after 4 and 12 weeks in baseline-position as well as in an elevated position of the leg.

RESULTS

Microcirculation parameters (oxygen saturation, blood flow, velocity) of the revascularized leg showed a significant increase in elevation and baseline position compared to the preoperative values in most analyses. No significant differences between the direct and indirect revascularized angiosome were apparent.

CONCLUSION

The light-guided spectrophotometry measurement proved to be feasible in terms of measuring changes in the microcirculation after leg revascularization. However, our data do not support the value of the "angiosome concept" concerning the individual changes in microperfusion of the foot in patients with CLI.

Oximetric angiosome imaging in diabetic feet

PURPOSE

To develop a noncontrast oximetric angiosome imaging approach to assess skeletal muscle oxygenation in diabetic feet.

MATERIALS AND METHODS

In four healthy and five subjects with diabetes, the feasibility of foot oximetry was examined using a 3T clinical magnetic resonance imaging (MRI) scanner. The subjects' feet were scanned at rest and during a toe-flexion isometric exercise. The oxygen extraction fraction of skeletal muscle was measured using a susceptibility-based MRI method. Our newly developed MR foot oximetric angiosome model was compared with the traditional angiosome model in the assessment of the distribution of oxygen extraction fraction.

RESULTS

Using the traditional angiosome during the toe-flexion exercise, the oxygen extraction fraction in the medial foot of healthy subjects increased (4.9 ± 3%) and decreased (-2.7 ± 4.4%) in subjects with diabetes (difference = 7.6%; 95% confidence interval = -13.7 ± 1.4; P = 0.02). Using the oximetric angiosome, the percent difference in the areas of oxygen extraction fraction within the 0.7-1.0 range (expected oxygen extraction fraction during exercise) between rest and exercise was higher in healthy subjects (8 ± 4%) than in subjects with diabetes (4 ± 4%; P = 0.02).

CONCLUSION

This study demonstrates the feasibility of measuring skeletal muscle oxygen extraction fraction in the foot muscle during a toe-flexion isometric exercise. Instead of assessing oxygen extraction fraction in a foot muscle region linked to a supplying artery (traditional angiosome), the foot oximetric angiosome model assesses oxygen extraction fraction by its different levels in all foot muscle regions and thus may be more appropriate for assessing local ischemia in ulcerated diabetic feet. J. Magn. Reson. Imaging 2016. J. MAGN. RESON. IMAGING 2016;44:940-946.

Outcomes and Influence of the Pedal Arch in Below-the-Knee Angioplasty in Patients with End-Stage Renal Disease and Critical Limb Ischemia

BACKGROUND

Management of dialysis patients with critical limb ischemia (CLI) still represents a challenge to vascular medicine, whereas the effects of the pedal arch quality in these patients with predominant affection of the infrapopliteal vessels have rarely been evaluated. Therefore, our aim was to analyze the outcomes of infrapopliteal angioplasty in the setting of chronic renal failure (end-stage renal disease) and evaluate the influence of the pedal arch involvement on clinical success.

METHODS

Prospective follow-up of 32 ERSD patients on hemodialysis (mean age, 72 years) with CLI and consecutive infrapopliteal angioplasty over a 5-year period 2010-2014 was performed. Mean follow-up was 10 months (range, 0-51 months). Statistical end points were defined for amputation-free survival, overall survival, and wound healing. Each patient's pedal arch was classified in 4 categories according to patency on completion angiography and the influence of the pedal arch quality on end points was assessed.

RESULTS

A total of 44 vessels in 32 ischemic legs were treated. Technical success was achieved in 96% of patients, no major complications were observed. A 30-day mortality rate amounted 6% with no procedure-related deaths. The 1-year amputation-free survival rate was 56% and 34% at 2 years. Two major amputations were required. Subsequent revascularization procedures were necessary in 11 patients (10 redo angioplasty, 1 pedal bypass graft). The pedal arch was classified as category I in 1 patient (3%), category IIa in 12 (38%), IIb in 3 (9%), and III in 16 patients (50%). No statistical significant differences in terms of survival or wound-healing rate were observed between those groups, and the pedal arch quality had no impact on predefined end points.

CONCLUSIONS

End-stage renal disease patients represent a subgroup with poor prognosis of limb salvage in CLI. Amputation-free survival remains poor and based on these data, an endovascular therapy is feasible and safe in these highly multimorbid patients. The quality of the pedal arch was not found to have any impact on wound healing or survival in the present study.

Current achievements with topical negative pressure to improve wound healing in dehiscent ischemic stumps of diabetic patients: a case series

Negative pressure wound therapy has been increasingly used either as a primary or as an adjunctive therapeutic measure to treat a variety of recalcitrant wounds during the past years. It is thought to act by creating a local environment that promotes cell proliferation, angiogenesis, and granulation tissue formation, leading to accelerated wound healing to the point of spontaneous closure or reducing the wound size to facilitate significantly further surgical reconstruction. This case series presents our preliminary experience with the use of a Topical Negative Pressure system in the treatment of challenging ischemic wounds of diabetic patients. It aims to underscore its beneficial effects and explore its potential role in the management of ischemic amputated stumps to avoid ipsilateral re-amputation at a higher level.