A research-based, current approach to diabetes-related acute foot infections and chronic osteomyelitis

INTRODUCTION

Diabetic foot infections (DFIs) and diabetic foot osteomyelitis (DFO) are common and serious complications in patients with diabetes, often leading to severe morbidity (including amputation) and even mortality. Professional footcare, prompt diagnosis and appropriate treatment are crucial to preventing limb loss and improving outcomes in infections.

AREAS COVERED

This narrative review addresses the management of all DFIs, including the approach to clinical evaluation, appropriate diagnostic methods, and optimal therapeutic strategies. We specifically address key areas in antibiotic therapy, and surgical interventions and techniques. Based on our literature review and extensive, multidisciplinary experience, we developed a novel treatment flowchart specifically for the management of DFO.

EXPERT OPINION

Managing DFIs, including DFO, requires a multidisciplinary approach tailored to each patient's clinical presentation. While antibiotics, surgery, and wound care each play a crucial role, the decision-making process should always consider the infection's severity and chronicity. Our proposed flowchart for DFO management emphasizes the importance of logically-sequenced, easy to apply and tailored interventions to prevent unnecessary amputations and improve outcomes. Further research is needed to further refine this flowchart in clinical practice and demonstrate its effectiveness.

Association Between the Society for Vascular Surgery (SVS)-WIfI (Wound, Ischemia, Foot Infection) Classification, Wagner-Meggitt Classification, and Amputation Rate in Patients With Diabetic Foot Infection

Diabetic foot infection (DFI) is a common problem in patients with diabetic foot disease. Amputations and other complications of DFI lead to significant morbidity and mortality. The Society for Vascular Surgery (SVS)-WIfI (wound, ischemia, and foot infection) classification system can evaluate the benefit from revascularization and the risk of amputation in 1 and 3 years. We aimed to evaluate SVS-WIfI and Wagner-Meggitt (WM) prediction of DFI outcome, and to determine factors associated with major amputation and mortality rate. The patients with diabetes who presented between June 2018 and May 2020 with characteristics suggesting a more serious DFI or potential indications for hospitalization were reviewed in this cohort study. Demographic data, clinical characteristics, and type of revascularization were evaluated. One-year and 3-year amputation and mortality rates were the main outcomes. The grading of WM classification and the SVS-WIfI score were compared between amputation and nonamputation groups. Association between mortality and comorbidity were analyzed. One hundred and thirty-one patients admitted with DFI were included in study. And 73.28% had peripheral arterial disease (PAD). The 1-year and 3-year major amputation rates were 16.03% and 26.23%, respectively. Seventy-eight (59.54%) patients required minor amputation to control infection before revascularization. PAD (risk ratio [RR] 1.47: 95% confidence interval [CI] 1.29-1.67, P = .032), benefit from revascularization clinical stage 3 on SVS-WIfI score (RR 4.56: 95%CI 1.21-17.21, P = 0.007), and high WM classification score (RR 9.46: 95% CI 5.65-15.82, P < 0.001) were associated by multivariate analysis with high amputation rates. 1-year & 3-year amputation risk on SVS-WIfI score were not associated with amputation rates in DFI (P = .263 and .496). Only 9 (6.8%) patients were lost to follow up during the 3-year period. WM classification score, SVS-WIfI score on benefit from revascularization, and PAD were strongly associated with major amputation rates in patients with DFI.

Medial Arterial Calcification and the Risk of Amputation of Diabetic Foot Ulcer in Patients With Diabetic Kidney Disease

We assessed the risk factors for major amputation of diabetic foot ulcers (DFUs) in patients with diabetic kidney disease (DKD) stages 3b-5. For DFU assessment, in addition to DFU location and presence of infection, ischemia, and neuropathy, vascular calcification was assessed using the medial arterial calcification (MAC) score. Of 210 patients, 26 (12.4%) underwent major amputations. Only the location and extension of DFU, represented by Texas grade differed between the minor and major amputation groups. However, after adjusting for covariates, ulcer location of mid- or hindfoot (vs. forefoot, odds ratio [OR] = 3.27), Texas grades 2 or 3 (vs. grade 0, OR = 5.78), and severe MAC (vs. no MAC, OR = 4.46) was an independent risk factor for major amputation (all P < 0.05). The current use of antiplatelets was a possible protective factor for major amputations (OR = 0.37, P = 0.055). In conclusion, DFU with severe MAC is associated with major amputation in patients with DKD.

Retrospective cohort study of long-term outcomes and prognostic factors for survival after lower extremity amputation in patients with diabetes

AIMS

Lower extremity amputation (LEA) is a pivotal event for patients with diabetes. This study aimed to provide updated data on the outcomes and prognostic factors after LEA for patients with diabetes.

METHODS

This retrospective cohort study included all LEAs (n = 1081) performed at Tampere University Hospital between February 2007 and September 2020. Overall survival (OS) and major amputation-free survival were evaluated.

RESULTS

Index amputation level was below ankle in 65 % (n = 704) of patients, below knee in 14 % (n = 154) of patients, and above knee in 21 % (n = 223) of patients. In the whole population, OS was 75.8 % (CI 95 %: 73.3-78.3) at one year and 38.3 % (CI 95 %: 34.7-41.7) at five years. Higher age, peripheral artery disease (PAD), more proximal amputation level, and lower glomerular filtration rate (GFR) reduced OS. Multiple amputations and diagnosed dyslipidemia or hypertension associated with improved OS. Further, age, PAD, and GFR were identified as significant factors for major amputation free survival.

CONCLUSIONS

OS after LEA is poor. After major amputation, the risk for death is higher compared to minor amputation. Recurrent amputation is associated with improved OS. Further, ischemia and renal disease are significant factors for inferior OS.

Notoginsenoside R1 Facilitated Wound Healing in High-Fat Diet/Streptozotocin-Induced Diabetic Rats

Diabetic ulcers bring about high morbidity and mortality in patients and cause a great economic burden to society as a whole. Since existing treatments cannot fulfil patient requirements, it is urgent to find effective therapies. In this study, the wound healing effect of topical notoginsenoside R1 (NR1) treatment on diabetic full-thickness wounds in type II diabetes mellitus (T2DM) was induced by the combination of a high-fat diet and streptozotocin (STZ) injection. NR1 significantly increased the wound closure rate, enhanced extracellular matrix (ECM) secretion, promoted collagen growth, increased platelet endothelial cell adhesion molecule-1 (CD31) expression, and decreased cleaved caspase-3 expression. RNA-Seq analysis identified ECM remodeling and inflammation as critical biological processes and Timp1 and Mmp3 as important targets in NR1-mediated wound healing. Further experiments showed that NR1-treated wounds demonstrated higher expression of tissue inhibitor of metalloproteinase 1 (TIMP1) and transforming growth factor-β1 (TGFβ1) and lower expression of matrix metallopeptidase 9 (MMP9), matrix metallopeptidase 3 (MMP3), interleukin-1β (IL-1β), and interleukin-6 (IL-6) than diabetic wounds. These investigations promote the understanding of the mechanism of NR1-mediated diabetic wound healing and provide a promising therapeutic drug to enhance diabetic wound healing.

Major Amputation Profoundly Increases Mortality in Patients With Diabetic Foot Infection

Introduction: An acute diabetic foot infection (DFI) is a serious condition and a leading cause of hospitalization and major amputation in patients with diabetes. Aim of this study was to evaluate the long term survival and risk factors for death and amputation after the DFI requiring hospital treatment.

Materials and Methods: A retrospective study included all adult patients hospitalized for DFI treatments during 2010–2014. Overall survival (OS) and amputation free survival (AFS) (without major amputation) was calculated. We performed a Cox regression analysis of several clinical parameters to evaluate the effects of clinical parameters on overall and amputation-free survival.

Results: Total of 324 patients with mean age of 66.8 (SD 12.8) years were included. The one- and five-year OS after DFI 81.2% (95%CI 77.5–84.9%) and 49.7% (95%CI 44.8–54.6%), respectively. Major amputation, wound ischemia, older age, and a low glomerular filtration rate reduced the OS after DFI. After a major amputation, the one- and five-year OS was 41.7% (95%CI 13.9–69.5) and 8.3% (95%CI 0.0–24.0%), respectively. Wound ischemia, older age, and elevated C-reactive protein reduced AFS. In contrast, hypertensive medication use was identified as a protective factor.

Conclusion: Mortality after a DFI remains high and is significantly increased after a major amputation. Findings highlight the importance of early wound and ischemia management for DFI prevention.

2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines

Since 1980, the American College of Cardiology (ACC) and American Heart Association (AHA) have translated scientific evidence into clinical practice guidelines with recommendations to improve cardiovascular health. These guidelines, based on systematic methods to evaluate and classify evidence, provide a cornerstone of quality cardiovascular care.

In response to reports from the Institute of Medicine1 ,2 and a mandate to evaluate new knowledge and maintain relevance at the point of care, the ACC/AHA Task Force on Clinical Practice Guidelines (Task Force) modified its methodology.3 –5 The relationships among guidelines, data standards, appropriate use criteria, and performance measures are addressed elsewhere.5

2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines

Since 1980, the American College of Cardiology (ACC) and American Heart Association (AHA) have translated scientific evidence into clinical practice guidelines with recommendations to improve cardiovascular health. These guidelines, based on systematic methods to evaluate and classify evidence, provide a cornerstone of quality cardiovascular care.

In response to reports from the Institute of Medicine1 ,2 and a mandate to evaluate new knowledge and maintain relevance at the point of care, the ACC/AHA Task Force on Clinical Practice Guidelines (Task Force) modified its methodology.3 –5 The relationships among guidelines, data standards, appropriate use criteria, and performance measures are addressed elsewhere.5

Re-organizing inpatient care saves legs in patients with diabetic foot infections

AIMS

In this study, we evaluated the effects of the re-organization of inpatient care for patients with a diabetic foot infection, and the implementation of a specialized multi-disciplinary wound department at an academic tertiary hospital.

METHODS

This was a retrospective cohort study, comprising 272 patients treated for diabetic foot infections in 2006-2007 (Group 1, n=124) and 2013-2014 (Group 2, n=148). In 2012, inpatient care of all chronic wounds was centralized at a single wound department with a multi-disciplinary team. We assessed group outcome before and after the re-organization.

RESULTS

During the 7-year study period, the incidence of hospitalized patients with a diabetic foot infection increased 19%. After initiating the re-organization, the below-the-knee amputation rate was significantly reduced (25.8% vs. 9.5%, p<0.001). The median time from admission to surgical intervention decreased from 5days to 2days, p<0.001. The length of hospitalization also tended to decrease after the reorganization.

CONCLUSIONS

The findings of this study demonstrate the benefits of treating diabetic foot infections at a specialized wound department with a multi-disciplinary team. The benefits were achieved by simply distributing the workload and organizing schedules, without new investments or additional personnel. The findings of this study indicate that patients with diabetic foot infections present a challenge that is beyond the expertise of a single field of medicine. A working collaboration between disciplines and a specialized wound department are central in achieving better results.

A prospective, multicentre, open-label, single-arm clinical trial for treatment of chronic complex diabetic foot wounds with exposed tendon and/or bone: positive clinical outcomes of viable cryopreserved human placental membrane

Complex diabetic foot ulcers (DFUs) with exposed tendon or bone remain a challenge. They are more susceptible to complications such as infection and amputation and require treatments that promote rapid development of granulation tissue and, ultimately, reepithelialisation. The clinical effectiveness of viable cryopreserved human placental membrane (vCHPM) for DFUs has been established in a level 1 trial. However, complex wounds with exposed deeper structures are typically excluded from randomised controlled clinical trials despite being common in clinical practice. We report the results of a prospective, multicentre, open‐label, single‐arm clinical trial to establish clinical outcomes when vCHPM is applied weekly to complex DFUs with exposed deep structures. Patients with type 1 or type 2 diabetes and a complex DFU extending through the dermis with evidence of exposed muscle, tendon, fascia, bone and/or joint capsule were eligible for inclusion. Of the 31 patients enrolled, 27 completed the study. The mean wound area was 14·6 cm², and mean duration was 7·5 months. For patients completing the protocol, the primary endpoint, 100% wound granulation by week 16, was met by 96·3% of patients in a mean of 6·8 weeks. Complete wound closure occurred in 59·3% (mean 9·1 weeks). The 4‐week percent area reduction was 54·3%. There were no product‐related adverse events. Four patients (13%) withdrew, two (6·5%) for non‐compliance and two (6·5%) for surgical intervention.

Effectiveness of Autologous Stem Cell Therapy for the Treatment of Lower Extremity Ulcers: A Systematic Review and Meta-Analysis

Primary studies in animal models and humans have suggested the therapeutic potential of autologous stem cell for treating chronic lower extremity ulcers. However, the results of pilot randomized controlled trials (RCTs) in humans have been inconsistent. A meta-analysis of RCTs was performed to evaluate the role of autologous stem cell-based therapy for lower extremity ulcers.Studies were identified during a systematic search of Medline, Embase, Cochrane's library, and references cited in related reviews and studies. Studies were included if they were RCTs published in English, recruited patients with lower extremity ulcers who were assigned to either a group for the topical therapy with autologous stem cells, and reported data regarding the healing of the ulcers.Relative risks (RRs) for healing rate and standardized mean differences (SMDs) for the changes in the mean sizes of ulcers were evaluated with a random-effects model. Overall, autologous stem cell-based therapy was associated with better healing of lower extremity ulcers (12 comparisons, 290 patients, RR for partial healing = 3.07, 95% confidence interval [CI] = 1.14-8.24, P = 0.03; RR for complete healing = 2.26, 95% CI = 1.48-3.16, P < 0.001) with little heterogeneity (I = 0%). Moreover, autologous stem cell-based therapy was associated with a greater reduction in mean ulcer size (SMD = -0.63, 95% CI = -1.03 to -0.22, P = 0.002). Subgroup analyses indicated that stem cells from peripheral blood and bone marrow seemed to exert similar beneficial effects on the healing of ulcers. Stem cell therapy was not associated with any increased risks for adverse events. The optimized sources, amounts, and delivery methods of stem cell -based therapy for patients with chronic lower extremity ulcers need to be determined, and the long-term effects of stem cell-based therapy on clinical outcomes need further exploration.Autologous stem cell-based therapy is effective and safe for improving the healing of chronic lower extremity ulcers and large-scale RCTs are needed to confirm our findings.