Illustration of Cost Saving Implications of Lower Extremity Nerve Decompression to Prevent Recurrence of Diabetic Foot Ulceration

Improving Microcirculation With Nerve Decompression: The Missing Link in Treatment of Diabetic Neuropathy and Diabetic Foot Ulcer

Sympathetic dysfunction in skin is well known in diabetic peripheral neuropathy. This produces dry, cracked, peeling skin susceptible to infection and also epidermal microcirculation insufficiency. Impaired autonomic neurovascular control opens dermal arterio-venous anastomoses and shunts microcirculation away from the epidermis and impairs skin oxygenation and nutrition. Few recognise that diabetic neuropathy includes swelling-induced entrapment neuropathy. Multiple peripheral nerves, swollen by the secondary polyol metabolic pathway, suffer local compressions at fibro-osseous tunnels. This includes the C-fibres controlling autonomic functions which constitute most of the nerve axons. No current standard of care therapy addresses the sympathetic-regulated neurovascular impairment of skin microcirculation in diabetes. Epineurolysis surgery for peripheral nerve decompression relieves local axonal compressions and generates recovery of sub-epidermal capillary flow. Clinical and animal diabetes studies have demonstrated objective improvements to epidermal hypoxia, demyelination and axonal histology. Seven surgery studies find an average 1.39% recurrence and zero amputations after prior Risk Class 3 wound healing in a mean of 1.78 years of follow-up. Deficits of electrophysiology, transcutaneous oxygenation and vasa nervorum circulation also improve. Surgically improved microcirculation is physiology-based. Nerve decompression minimises diabetic peripheral neuropathy, avoids initial diabetic foot ulcers, promotes neuropathic diabetic foot ulcer healing and minimises ulcer recurrences and subsequent amputation. The observational studies of these important benefits suggest wide application to the complications of diabetes neuropathy and beg for academic attention to Level 1 EBM confirmation.

Decompressive Nerve Surgery Associated with Low Diabetic Foot Ulcer Rate and High-Risk Bias: A Systematic Review and Meta-Analysis

BACKGROUND

Diabetic sensorimotor polyneuropathy (DSPN) occurs in 50% of patients with diabetes mellitus (DM). Up to 70% of DM patients incur diabetic foot ulcers (DFUs). Of those with DSPN, 20% develop DFUs. Decompression nerve surgery (DNS) purportedly improves DSPN and DFU. As there is no accurate, pooled DFU incidence following DNS, the authors performed a systematic review and meta-analysis of DFU incidence following DNS. Given the 60% global DFU incidence, they hypothesized a lower, pooled DFU incidence following DNS.

METHODS

Two authors searched 6 databases from database inception to July of 2023 for DNS clinical studies. Primary tracked outcomes were new and recurrent DFU incidence following DNS. Included studies were clinical studies of adult patients with DM, DNS of the tibial nerve(s) at minimum, 3-month minimum follow-up, and reported new or recurrent DFU incidence following DNS. Nonclinical and nonhuman studies were excluded. The Grades of Recommendation, Assessment, Development, and Evaluation and Methodological Index for Non-Randomized Studies instruments were used to evaluate evidence. Using a random-effects model, a meta-analysis of DFU incidence was conducted.

RESULTS

A total of 1074 studies were identified and 208 were screened. Thirteen studies yielded 2466 and 540 new and recurrent patients with DFU incidences of 1% and 5%, respectively. Primary studies had low-level evidence and high-risk bias, including selection bias. A subanalysis of sample size and follow-up length produced similar results. Further covariable analyses were precluded because of incomplete primary study data.

CONCLUSIONS

Despite a low DFU incidence following DNS, clinical studies provide too low-level evidence and high-risk bias for any recommendations. Future randomized controlled trials may validate DNS for DFU management.

Comparative Effectiveness of Amniotic and Chorionic Grafts in the Treatment of Lower-Extremity Diabetic Ulcers Using U.S. Medicare Real-World Evidence (2018-2022): A Retrospective Observational Cohort

Objective: Lower-extremity diabetic ulcers (LEDUs) affect more than 500,000 U.S. Medicare beneficiaries each year. Dehydrated human amnionic and chorionic allografts (DHACAs) are clinically effective complements to standard of care (SoC; e.g., surgical debridement, offloading, infection, and moisture control) when treating LEDUs. However, Medicare and commercial payer coverage have restricted access to DHACAs. Our objective was to compare the effectiveness of DHACAs versus SoC among Medicare beneficiaries with LEDUs for reduction of adverse outcomes such as mortality, recurrency, and major amputation. Approach: We analyzed a retrospective cohort of U.S. Medicare claims for LEDUs between 2018 and 2022. LEDU claims were collapsed into episodes of care (EOC). Frequency distribution of characteristics was compared using univariate and bivariate statistics. Zero-inflated binomial regression with 1:1 nearest-neighbor propensity score matching evaluated six main outcome measures: mortality; wound recurrence; major amputation; minor amputation; emergency department (ED) utilization; and readmission. Results: There were 25,760 Medicare EOCs between 2018 and 2022 representing 12,880 matched samples in the DHACA and SoC cohorts. DHACAs were associated with a 20% reduction in 30-day mortality (95% confidence interval [CI]:10%, 29%), 28% reduction in risk of major amputation (95% CI: 19%, 36%), 9% reduction in ED utilization (95% CI: 3%,14%), and 8% reduction in 30-day readmission (95% CI: 2%, 13%). DHACAs were noninferior for minor amputation rates and wound recurrence compared to SoC cohort. Conclusion: Beneficiaries with LEDUs benefit significantly from DHACAs on multiple outcomes, including a lower risk of mortality. Providers should examine the appropriateness of DHACAs for patients with LEDU as part of wound management. Medicare and commercial payers should consider improved outcomes when defining coverage policies that restrict access to DHACAs given the observed benefits.

Objective Evidence That Nerve Decompression Surgery Reduces Neuropathic DFU Recurrence Risk to Less than 5%

Significance: Despite 20 years of research and new treatment methods, diabetic foot ulcer (DFU) remains a common problem with frequent recurrences and complications. Recent Advances: There are reports that nerve decompression (ND) surgery has been observed to produce significantly fewer DFU recurrences than standard of care (SOC). The explanation of this apparent superiority has not been understood. Critical Issues: Microcirculation is understood to be involved in diabetic peripheral neuropathy (DPN) and DFU. There is an underappreciation of the participation in DPN of entrapment neuropathy (EN) due to nerve swelling and impingement in fibro-osseous tunnels. Reducing c-fiber compression in EN by ND generates recovery of subepidermal capillary flow. ND studies have found improved neuromuscular function and epidermal microcirculation phenomena, including chronic capillary ischemia (CCI) and pressure-induced vasodilatation (PIV). There is no current therapy recommended for impaired microcirculation. Clinical and animal evidence has demonstrated that release of locally compressed peripheral nerves improves the epidermal microcirculation which is under sympathetic control. Future Directions: Using epineurolysis to relieve nerve compressions is a physiology-based therapeutic intervention and provides the scientific foundation clarifying how ND reduces DFU recurrence risk. Incorporating ND with current SOC treatments could improve DFU recurrence risk, hard-to-heal ulcers, neuroischemic wounds, amputation risk, and the resulting costs to society. More studies using ND for DFU, especially evidence-based medicine Level I studies, are needed to confirm these preliminary outcomes.

The NIDDK Diabetic Foot Consortium

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Diabetic Foot Consortium (DFC) was established in September 2018 by the NIDDK to build an organization to facilitate the highest quality of clinical research on diabetic foot ulcers (DFUs) that will answer clinically significant questions to improve DFU healing and prevent amputations. The initial focus of the DFC is to develop and validate biomarkers for DFUs that can be used in clinical care and research. The DFC consists of a data coordinating center (DCC) for operational oversight and statistical analysis, clinical sites for participant recruitment and evaluation, and biomarker analysis units (BAUs). The DFC is currently studying biomarkers to predict wound healing and recurrence and is collecting biosamples for future studies through a biorepository. The DFC plans to address the challenges of recruitment and eligibility criteria for DFU clinical trials by taking an approach of "No DFU Patient Goes Unstudied." In this platform approach, clinical history, DFU outcome, wound imaging, and biologic measurements from a large number of patients will be captured and the in-depth longitudinal data set will be analyzed to develop a computational-based DFU risk factor profile to facilitate scientifically sound clinical trial design. The DFC will expand its platform to include studies of the role of social determinants of health, such as food insecurity, housing instability, limited health literacy, and poor social support. The DFC is starting partnerships with the broad group of stakeholders in the wound care community.

Impact of repeated remote ischemic conditioning on diabetic foot ulcers: A proof-of-concept study

Patients with a diabetic foot ulcer (DFU) suffer disabilities and are at increased risk for lower extremity amputation. Current standard of care includes debridement, topical antibiotics, and weight off-loading-still resulting in low rates of healing. Previous small-scale research has indicated that repeated remote ischemic conditioning (rRIC) is a novel modality that delivers significantly higher DFU healing rates. This proof-of-concept study was performed to expand the research on the utility of rRIC as an adjunctive treatment in the healing of chronic DFUs. Forty subjects (41 wounds) received rRIC treatment three times weekly in addition to standard of care for 12 weeks. Subjects that did not heal in this time frame but had a significant reduction in wound size were eligible to continue for an 8-week extension period. By the end of the extension period, 31 of the 41 DFU wounds (75.6%) in this study were determined to be healed. This compares favourably to the 25-30% standard of care average healing rate. For additional comparison, another group of patients receiving standard of care alone, by the same investigator, was selected and matched by wound size at baseline and wound location. For this matching cohort, after 20 weeks of treatment, only 15 of the 41 DFU comparison wounds (36.6%) were determined to be healed, in line with other standard of care results. In the rRIC treatment group, the 10 wounds that did not heal, experienced an average reduction in wound area of 54.3%. The results of this proof-of-concept study reinforce earlier evidence that the addition of rRIC to local wound care significantly improves the healing of chronic diabetic foot ulcers.

Observed impact of skin substitutes in lower extremity diabetic ulcers: lessons from the Medicare Database (2015-2018)

OBJECTIVE

To evaluate large propensity-matched cohorts to assess outcomes in patients receiving advanced treatment (AT) with skin substitutes for lower extremity diabetic ulcers (LEDUs) versus no AT (NAT) for the management of LEDUs.

METHOD

The Medicare Limited Dataset (1 October 2015 through 2 October 2018) were used to retrospectively analyse people receiving care for a LEDU treated with AT or NAT (propensity-matched Group 1). Analysis included major and minor amputations, emergency department (ED) visits and hospital readmissions. In addition, AT following parameters for use (FPFU) was compared with AT not FPFU (propensity-matched Group 2). A paired t-test was used for comparisons of the two groups. For comparisons of three groups, the Kruskal-Wallis test was used. A Bonferroni correction was performed when multiple comparisons were calculated.

RESULTS

There were 9,738,760 patients with a diagnosis of diabetes, of whom 909,813 had a LEDU. In propensity-matched Group 1 (12,676 episodes per cohort), AT patients had statistically fewer minor amputations (p=0.0367), major amputations (p<0.0001), ED visits (p<0.0001), and readmissions (p<0.0001) compared with NAT patients. In propensity-matched Group 2 (1131 episodes per cohort), AT FPFU patients had fewer minor amputations (p=0.002) than those in the AT not FPFU group.

CONCLUSION

AT for the management of LEDUs was associated with significant reductions in major and minor amputation, ED use, and hospital readmission compared with LEDUs managed with NAT. Clinics should implement AT in accordance with the highlighted parameters for use to improve outcomes and reduce costs.

Health economic evaluation of different treatment strategies for peripheral entrapment mononeuropathies: a systematic review

Introduction: In this era of cost-conscious health systems, it is of utmost importance to identify and establish the most cost-effective treatment option. However, in the case of peripheral entrapment mononeuropathies there is alack of data regarding economically effective treatment strategies. Therefore, the objective was to conduct an economic evaluation including both costs and benefits of various treatment strategies applied to peripheral entrapment mononeuropathies to estimate the relative cost-effective treatment regimens.Areas covered: Over the 19 years, seven excellent-high quality economic evaluations of three types of peripheral entrapment mononeuropathies were identified in four countries. Our findings showed that surgery was the most cost-effective therapy followed by same cost efficacy of infiltrative therapy and conservative therapy for peripheral entrapment mononeuropathies. However, the fact that surgery was the most common comparator (n = 6) in our selected studies cannot be neglected.Expert opinion: Due to huge methodological variability, the finding of surgery as the cost-effective treatment strategy remains tentative and the decision about the most suitable clinical and cost-effective therapy should be individualized from case to case. Moreover, the economic evaluation of all possible treatment strategies for peripheral entrapment mononeuropathies over alonger period of analysis is required in future studies.

Ultrasound-guided decompression surgery of the distal tarsal tunnel: a novel technique for the distal tarsal tunnel syndrome-part III

BACKGROUND

The aim of this study was to provide a safe ultrasound-guided minimally invasive surgical approach for a distal tarsal tunnel release concerning nerve entrapments.

METHODS AND RESULTS

The study was carried out on ten fresh-frozen feet. All of them have been examined by high-resolution ultrasound at the distal tarsal tunnel. The surgical approach has been marked throughout the course of the medial intermuscular septum (MIS, the lateral fascia of the abductor hallucis muscle). After the previous steps, nerve decompression was carried out through a MIS release through a 2.5 mm (± 0.5 mm) surgical portal. As a result, an effective release of the MIS has been obtained in all fresh-frozen feet.

CONCLUSION

The results of our anatomic study indicate that this novel ultrasound-guided minimally invasive surgical approach for the release of the MIS might be an effective, safe and quick decompression technique treating selected patients with a distal tarsal tunnel syndrome.

Nerve decompression and neuropathy complications in diabetes: Are attitudes discordant with evidence?

External neurolysis of the nerve at fibro-osseous tunnels has been proprosed to treat or prevent signs, symptoms, and complications in the lower extremity of diabetes patients with sensorimotor polyneuropathy. Nerve decompression is justified in the presence of symptomatic compressed nerves in the several fibro-osseous tunnels of the extremities, which are known to be frequent in diabetes. Quite a body of literature has accumulated reporting results after such nerve decompression in the leg, describing pain relief and sensibility improvement, as well as balance recovery, diabetic foot ulcer prevention, curtailed ulcer recurrence risk, and amputation avoidance. Historical academic hesitance to endorse surgical treatments for pain and numbness in diabetes was based primarily on the early retrospective reports' potential for bias and placebo effects, and that the hypothetical basis for surgery lies outside the traditional etiology paradigm of length-dependent axonopathy. This reticence is here critiqued in view of recent studies using objective, measured outcome protocols which nullify such potential confounders. Pain relief is now confirmed with Level 1 studies, and Level 2 prospective information suggests protection from initial diabetic foot ulceration and most neuropathic ulcer recurrences. In view of the potential for nerve decompression to be useful in addressing some of the more difficult, expensive, and life altering complications of diabetic neuropathy, this secondary compression thesis and operative treatment methodology may deserve reassessment.

Rationale, Science, and Economics of Surgical Nerve Decompression for Diabetic Neuropathy Foot Complications

Nerve decompression is effective and safe for dealing with the pain and numbness symptoms of the frequent nerve compression entrapments in diabetic symmetric peripheral neuropathy (DSPN). Evidence has accumulated of balance and stability improvements and protection against diabetic foot ulceration, recurrence and its complication cascade. Nerve decompression proffers significant benefit versus the large socioeconomic costs of DSPN complications. Advancing understanding of the mechanism of nerve compression and altered axonal activity in diabetes clarifies the basis of clinical benefit. Clinicians should seek out and recognize nerve entrapments and consider advising nerve decompression for relief of DSPN symptoms and prevention of complications.