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

Confounding factors in peripheral thermal recovery time after active cooling

OBJECTIVES

The effectiveness of normal physiological thermoregulation complicates differentiation between pathologic changes in medical thermography associated with peripheral artery disease and a number of other clinical conditions. In this study we investigate a number of potential confounding factors to the thermal recovery rate after active limb cooling, with the main focus on age and sex.

APPROACH

The source data consists of 53 healthy individuals with no diagnosed cardiovascular disease or reported symptoms and with a mean age of 38.4 (± 12.1) years. The sample population was further divided into male (N = 14) and female groups (N = 39). The thermal recovery time was measured using two thermal cameras from both lower limbs on plantar and dorsal sides. The active cooling was achieved using moldable cold pads placed on the plantar and dorsal side of the lower limb. The recovery was measured until the temperature had reached a stable level. The recovery time was determined from an exponential fit to the measured data.

RESULTS

The correlation between the thermal recovery time constant and age varied from low to moderate linear correlation (0.31 ≤ ⍴ ≤ 70), depending on the inspected region of interest, with a higher statistically significant correlation in the medial regions. The contralateral limb temperature differences or the thermal time constants did not have statistically significant differences between the male and female sexes. Further, the secondary metrics such as participant's body mass, body-mass index, or systolic blood pressure had low or no correlation with the thermal recovery time in the study group.

CONCLUSION

The thermal recovery time constant after active cooling appears as a relatively independent metric from the majority of the measured potential confounding factors. Age should be accounted for when performing thermal recovery measurements. However, dynamic thermal imaging and its methodologies require further research and exploration.

A focused review on hyaluronic acid contained nanofiber formulations for diabetic wound healing

The significant clinical challenge presented by diabetic wounds is due to their impaired healing process and increased risk of complications. It is estimated that a foot ulcer will develop at some point in the lives of 15-25 % of diabetic patients. Serious complications, including infection and amputation, are often led to by these wounds. In the field of tissue engineering and regenerative medicine, nanofiber-based wound dressings have emerged in recent years as promising therapeutic strategies for diabetic wound healing. Hyaluronic acid (HA), among various nanofiber materials, has gained considerable attention due to its unique properties, including biocompatibility, biodegradability, and excellent moisture retention capacity. By promoting skin hydration and controlling inflammation, a crucial role in wound healing is played by HA. Wounds are also helped to heal faster by HA through the regulation of inflammation levels and signaling the body to build more blood vessels in the damaged area. Great potential in various applications, including wound healing, has been shown by the development and use of nanofiber formulations in medicine. However, challenges and limitations associated with nanofibers in medicine exist, such as reproducibility, proper characterization, and biological evaluation. By providing a biomimetic environment that enhances re-epithelialization and facilitates the delivery of active substances, nanofibers promote wound healing. In accelerating wound healing, promising results have been shown by HA-contained nanofiber formulations in diabetic wounds. Key strategies employed by these formulations include revascularization, modulation of the inflammation microenvironment, delivery of active substances, photothermal nanofibers, and nanoparticle-loaded fabrics. Particularly crucial is revascularization as it restores blood flow to the wound area, promoting healing. Wound healing can also be enhanced by modulating the inflammation microenvironment through controlling inflammation levels. Future perspectives in this field involve addressing the current challenges and limitations of nanofiber technology and further optimizing HA-contained nanofiber formulations for improved efficacy in diabetic wound healing. This includes exploring new fabrication techniques, enhancing the biocompatibility and biodegradability of nanofibers, and developing multifunctional nanofibers for targeted drug delivery. Not only does writing a review in the field of nanofiber-based wound dressings, particularly those containing hyaluronic acid, allow us to consolidate our current knowledge and understanding but also broadens our horizons. An opportunity is provided to delve deeper into the intricacies of this innovative therapeutic strategy, explore its potential and limitations, and envision future directions. By doing so, a contribution can be made to the ongoing advancements in tissue engineering and regenerative medicine, ultimately improving the quality of life for patients with diabetic wounds.

Angiosome Oriented or Least Diseased Vessel, Which Is the Optimal Target Arterial Path for Endovascular Revascularisation in Patients With Diabetic Foot Ulcers?

OBJECTIVE

The aims were to determine whether, when treating diabetic foot ulcers (1), selecting an angiosome directed (AD) vessel as the target arterial path (TAP) when candidate vessels have comparably severe disease impacts outcomes and (2) whether a more severely affected AD vessel or a less severely affected non-angiosome directed (NAD) vessel should be chosen.

METHODS

This was a retrospective observational study. Patients with diabetic foot ulcers who had undergone endovascular revascularisation in the institution between January 2016 and May 2020 and had been followed up for two years were included. Eligible patients were identified retrospectively and relevant data were collected from the institution's electronic medical records. The severity of the lesions was classified using the Global Limb Anatomic Staging System (GLASS). Outcomes between various subgroups were compared according to the severity of the lesions to determine the optimal TAP choice in each case.

RESULTS

The study cohort comprised 215 patients (216 limbs). The affected limbs were classified as follows: 93 (43.1%) as GLASS 1 - 2 AD; 27 (12.5%) as GLASS 1 - 2 NAD, 62 (28.7%) as GLASS 3 AD, and 34 (15.7%) as GLASS 3 NAD groups. In the GLASS 1 - 2 group, rates of ulcer healing, survival, and amputation free survival were higher and time to healing shorter in the AD than NAD group. In the GLASS 3 group, there were no significant differences between the AD and NAD groups for any studied outcome measures, including ulcer healing and overall survival. Using a more severely diseased AD as the TAP did not achieve significantly better outcomes than using a less severely affected NAD vessel.

CONCLUSION

Selecting the AD vessel may achieve better outcomes when two candidate TAPs belong to GLASS 1 - 2, whereas selecting the least diseased vessel as the TAP regardless of AD or NAD status may be preferable in other situations.

Assessment of chronic limb threatening ischemia using thermal imaging

OBJECTIVES

Current chronic limb threatening ischemia (CLTI) diagnostics require expensive equipment, using ionizing radiation or contrast agents, or summative surrogate methods lacking in spatial information. Our aim is to develop and improve contactless, non-ionizing and cost-effective diagnostic methods for CLTI assessment with high spatial accuracy by utilizing dynamic thermal imaging and the angiosome concept.

APPROACH

Dynamic thermal imaging test protocol was suggested and implemented with a number of computational parameters. Pilot data was measured from 3 healthy young subjects, 4 peripheral artery disease (PAD) patients and 4 CLTI patients. The protocol consists of clinical reference measurements, including ankle- and toe-brachial indices (ABI, TBI), and a modified patient bed for hydrostatic and thermal modulation tests. The data was analyzed using bivariate correlation.

RESULTS

The thermal recovery time constant was on average higher for the PAD (88%) and CLTI (83%) groups with respect to the healthy young subjects. The contralateral symmetry was high for the healthy young group and low for the CLTI group. The recovery time constants showed high negative correlation to TBI (ρ = -0.73) and ABI (ρ = -0.60). The relation of these clinical parameters to the hydrostatic response and absolute temperatures (|ρ|<0.3) remained unclear.

CONCLUSION

The lack of correlation for absolute temperatures or their contralateral differences with the clinical status, ABI and TBI disputes their use in CLTI diagnostics. Thermal modulation tests tend to augment the signs of thermoregulation deficiencies and accordingly high correlations were found with all reference metrics. The method is promising for establishing the connection between impaired perfusion and thermography. The hydrostatic modulation test requires more research with stricter test conditions.

Angiosome-guided endovascular revascularization for treatment of diabetic foot ulcers with peripheral artery disease

OBJECTIVE

Because diabetic foot ulcers (DFUs) are difficult to heal and cause huge economic losses to society, accelerating their healing has become extremely important. The purpose of this study was to evaluate the effect of revascularization based on the angiosome concept on DFU.

MATERIALS AND METHODS

Between January 2018 and July 2020, 112 consecutive legs with DFUs in 111 patients who were discharged from the vascular surgery department of our hospital were retrospectively evaluated. The legs were assigned to two groups depending on whether direct arterial flow to the foot ulcer based on the angiosome concept was achieved. Comparisons of the ulcer healing rate, mean time to ulcer healing, major amputation rate, survival rate, and major amputation-free survival rate between the angiosome direct revascularization (DR) and angiosome indirect revascularization (IR) groups were performed.

RESULTS

DR was achieved in 71 legs (63%) compared with IR in 41 legs. The ulcer healing rate (70.4% in the DR group vs. 34.1% in the IR group, P < 0.01), the mean time to ulcer healing (7.01 ± 4.26 months vs. 10.09 ± 3.24months, P < 0.01), the survival rate (90.1% vs. 53.7%, P < 0.01), and the major amputation-free survival rate (81.7% vs. 48.8%, P < 0.01) were significantly higher in the DR group than in the IR group. Undergoing DR did not significantly reduce the major amputations rate compared with IR (13.4% and 34.1%, respectively, P = 0.15), but there might be a trend. In multivariate models, DR remained a significant predictor for ulcer healing (HR, 7.07; 95% confidence interval, 6.54-7.60, P < 0.01). Opening multiple infrapopliteal arteries in the DR group compared with restoring only one infrapopliteal artery did not significantly improve the the ulcer healing rate (P = 0.59), the mean time to ulcer healing (P = 0.70), major amputation rate (P = 0.83), the survival rate (P = 0.31), and the major amputation-free survival rate(P = 0.40).

CONCLUSIONS

Attaining a direct arterial flow based on the angiosome concept may be important for ulcer healing, survival, and amputation-free survival in diabetic foot patients. Opening multiple infrapopliteal arteries in DR patients may not improve the ulcer healing, survival, major amputation or amputation-free survival compared with single DR vessel patency.

Guidelines on diagnosis, prognosis, and management of peripheral artery disease in patients with foot ulcers and diabetes (IWGDF 2019 update)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the prevention and management of diabetic foot disease since 1999. This guideline is on the diagnosis, prognosis, and management of peripheral artery disease (PAD) in patients with foot ulcers and diabetes and updates the previous IWGDF Guideline. Up to 50% of patients with diabetes and foot ulceration have concurrent PAD, which confers a significantly elevated risk of adverse limb events and cardiovascular disease. We know that the diagnosis, prognosis, and treatment of these patients are markedly different to patients with diabetes who do not have PAD and yet there are few good quality studies addressing this important subset of patients. We followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology to devise clinical questions and critically important outcomes in the patient-intervention-comparison-outcome (PICO) format, to conduct a systematic review of the medical-scientific literature, and to write recommendations and their rationale. The recommendations are based on the quality of evidence found in the systematic review, expert opinion where evidence was not available, and a weighing of the benefits and harms, patient preferences, feasibility and applicability, and costs related to the intervention. We here present the updated 2019 guidelines on diagnosis, prognosis, and management of PAD in patients with a foot ulcer and diabetes, and we suggest some key future topics of particular research interest.

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.

Lower limb arterial intervention or autologous platelet-rich gel treatment of diabetic lower extremity arterial disease patients with foot ulcers

Background

To investigate whether lower limb vascular intervention or autologous platelet-rich gel (APG) treatment would benefit diabetic lower extremity arterial disease (LEAD) patients with foot ulcers.

Methods

A total of 82 diabetic LEAD patients with foot ulcers were recruited and divided into three groups: group A (30 patients received basal treatment), group B (21 patients received basal and APG treatment), and group C (31 patients received basal and lower limb vascular intervention treatment). All patients underwent routine follow-up visits for 6 months. The baseline characteristics and parameters were examined. After treatment, changes in all parameters from baseline were recorded. The differences between groups and the relationship among each parameter were determined.

Results

There were no differences in the ankle brachial index (ABI) or major amputation between groups A and B (P>0.05). Compared with groups A and B, the ABI and major amputation rate of group C were improved (P<0.05). There were no significant differences in transcutaneous oxygen partial pressure (TcPO₂), the heal rate or minor amputation between groups A and C (P>0.05). Compared with groups A and C, TcPO₂, the heal rate and minor amputation of group B were improved (P<0.05). The logistic regression analysis indicated that major amputation was mainly associated with the ABI, and minor amputation was mainly associated with TcPO₂. Lower limb vascular intervention improves the ABI and reduces major amputation, and APG improves TcPO₂ and reduces minor amputation.

Conclusions

In diabetic LEAD patients with foot ulcers, major amputation was mainly associated with the ABI, while minor amputation was mainly associated with TcPO₂. Interventional surgery (angioplasty) mainly improves the ABI, reduces the incidence of major amputation and improves the macrovasculature, and APG mainly improves local TcPO₂, reduces the incidence of minor amputation and improves the microcirculation.

Efficacy of a Ceratothoa oestroides Olive Oil Extract in Patients With Chronic Ulcers: A Pilot Study

Chronic wounds unresponsive to existing treatments constitute a serious disease burden. Factors that contribute to the pathogenesis of chronic ulcers include oxidative stress, comorbid microbial infections, and the type of immune system response. Preclinically, and in a case study, a formulation containing a Ceratothoa oestroides olive oil extract promoted wound healing. Patients with chronic venous and pressure ulcers, clinically assessed as being unresponsive to healing agents, were treated for 3 months with an ointment containing the C oestroides extract combined with antibiotic and/or antiseptic agents chosen according to the type of bacterial infection. Treatment evaluation was performed using the Bates-Jensen criteria with +WoundDesk and MOWA cell phone applications. After 3 months of treatment, C oestroides resulted in an average decrease of 36% in the Bates-Jensen score of ulcers ( P < .000), with the decrease being significant from the first month ( P < .007). The combined use of topically applied antibiotics and antiseptics efficiently controlled microbial ulcer infection and facilitated wound healing. In relation to other factors such as initial wound size, chronicity appeared to be an important prognostic factor regarding the extent of wound healing. Future clinical investigations assessing the wound healing efficacy of the C oestroides olive oil extract are warranted.

Retrograde dorsalis pedis angiosomal flow compromised by small puncture wound leading to transmetatarsal amputation

Pedal puncture wounds can precipitate a variety of complications, often resulting from a delay in treatment. Although the risk of infection predominates, direct vascular insult and subsequent ischemia is a lesser reported complication of these injuries. Consequently, this may have morbid results, especially on a background of pre-existing peripheral vascular disease. A case involving a small, plantar forefoot puncture wound, ultimately resulting in transmetatarsal amputation due to ischemic dry gangrene in an uncontrolled, but sensate, diabetic with profound vasculopathy is presented. This presentation highlights the importance of considering the potential for macrovascular damage via pedal puncture, and the potentially magnified complications in patients with dependent retrograde angiosomal flow and compromised collateral circulation. Based on a thorough analysis of the literature and the findings in this clinical example, a detailed investigation of angiosomal blood supply through direct and indirect vessel flow in patients with peripheral arterial disease incurring puncture wounds is advocated. In these patients, lack of compensatory avenues of the pedal circulation may portend significant tissue loss in an otherwise inoffensive situation. Knowledge of this complication, although rare, may prompt the clinician to assess for its potential, and emphasize a preference for direct revascularization in those with critical limb ischemia. Level of Clinical Evidence: 4.

BAD transmission and SAD distribution: a new scenario for critical limb ischemia

BACKGROUND

Most of the studies on peripheral artery disease (PAD) focused on above-the-ankle artery disease, while less is known about foot artery disease. We hypothesize a scenario were two different diseases can be present in PAD patients, big artery disease (BAD) and small artery disease (SAD), overlapping at the foot level; the aim of this study is to evaluate their prevalence and their correlation with risk factors and critical limb ischemia (CLI) in a large cohort of patients with symptomatic PAD.

METHODS

We retrospectively reviewed 1915 limbs of 1613 patients (502 females, mean age 72.4±10.8 years) who underwent angiography between September 2009 and November 2013. Age, sex, diabetes, smoke history, high blood pressure, dialysis and BMI were considered as risk factors. Logistic regression was performed to test the association of arterial lesions patterns and CLI, and to evaluate the association between risk factors and lesion localization.

RESULTS

SAD was present in 414 patients (25.2%). Patients with disease of any of plantar, dorsalis pedis arteries and SAD faced higher risk of CLI (OR=13.25, 95% CI: 1.69-104.16). SAD was associated with diabetes and dialysis (both: OR=4.85; dialysis only: OR=3.60; diabetes only: OR=1.70; none: reference OR; P<0.01), weight (underweight: OR=1.10; normal: reference OR; overweight: OR=0.81; obese: OR=0.60; P=0.03), while women and tobacco smokers were less likely to have SAD (women: OR=0.68; P<0.01; tobacco use: OR=0.54; P<0.01).

CONCLUSIONS

SAD was strongly and independently associated with CLI, diabetes and dialysis. Thus, SAD should be regarded as a leading actor in CLI.