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

Effect of leukocyte-platelet fibrin-rich wound reconstruction followed by full-thickness skin grafting in the treatment of diabetic foot Wagner grade 4 ulcer gangrene (toe area)

This study investigated the effect of L-PRF on promoting full-thickness skin grafting for the treatment of diabetic foot ulcer wounds and attempted to characterize the mechanism. In a retrospective study, we centrifugated 10-20 ml of venous blood at 1006.2 g for 20 min. The fibrin clot between the top oligocellular plasma layer and the bottom erythrocyte layer was extracted and directly used, without compression, to cover the wound after debridement. Patients who received L-PRF before skin grafting underwent surgery earlier than patients in the control group. Skin necrosis occurred in 7 patients (28%) in the L-PRF group and 16 (64%) in the control group. The difference was statistically significant, P < .05. The postoperative infection rate in the control group (56%) was significantly higher than that in the L-PRF group (24%), P < .05. During a mean follow-up of 1 year, ulcer recurrence occurred in 9 patients (36%) in the control group compared with 4 patients (16%) in the L-PRF group, P < .05. The final amputation rate was also higher in the control group (48%) than in the L-PRF group (20%). The difference is statistically significant, P < .05. The Maryland scale score and SF-36 score of the two groups of patients after treatment were significantly better than those before treatment, and the difference was statistically significant (P < .05). The L-PRF group (94.80 ± 4.14) had better foot scores at the last follow-up after treatment than the control group (88.84 ± 5.22) (P < .05). The results showed that L-PRF played a positive role in the treatment of Wagner grade 4 ulcer gangrene with free full-thickness skin grafts.

Bottom-up approach to build a 'precision' risk factor classification for diabetic foot ulcer healing. Proof-of-concept

AIMS

Diabetic foot ulcers (DFU) have a complex multifactorial pathophysiology. It is crucial to identify essential prognostic variables to streamline therapeutic actions and quality-of-care audits. Although SINBAD and University of Texas (UT), the most frequently used prognostic classification systems, were prospectively validated, not all individual parameters were shown to have consistent associations with healing. In this study, we used a bottom-up approach relying on robust methods to identify independent predictors of DFU healing.

METHODS

1,664 DFU patients were included by 34 Belgian diabetic foot clinics (DFCs). Twenty-one patient- and foot-related characteristics were recorded at presentation. Predictors of healing were identified using multivariable Cox proportional hazard regression. Multivariable models were built using backward regression with multiple imputation of missing values and bootstrapping.

RESULTS

Five essential independent variables were identified: presentation delay, history of minor amputation, ulcer location, surface area and ischemia. This 5 variable-model showed a better performance compared to models based on existing classification systems.

CONCLUSIONS

A bottom-up approach was used to build a prognostic classification for DFU healing based on large databases. It offers new insights and allows to tailor the classification to certain clinical settings. These 5 parameters could be used as a 'precision classification' for specialized DFCs.

Risk Reduction and Perioperative Complications in Patients With Diabetes and Multiple Medical Comorbidities Undergoing Charcot Foot Reconstruction

BACKGROUND

Modern patient safety programs focus on medical optimization of patients prior to surgery, regional anesthesia when possible, and hospitalist-orthopedic co-management during the perioperative period.

METHODS

Eighty-five consecutive patients with diabetes and multiple medical comorbidities underwent surgical reconstruction for acquired deformities secondary to Charcot foot arthropathy with circular ring fixation between 2016 and 2019. All patients participated in a standardized risk reduction program that included medical optimization prior to surgery, regional anesthesia whenever possible, and hospitalist-orthopedic co-management during the perioperative period. Charts were retrospectively reviewed for medical comorbidities, complications, and length of stay. The American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) Risk Calculator was used to retrospectively calculate their predicted perioperative risk.

RESULTS

On multivariable analysis, longer lengths of stay were associated with low preoperative hemoglobin values (rate ratio [RR], 1.36; P = .01) and congestive heart failure (RR, 1.42; P = .02). There were 22 (26%) complications, though only 10 (12%) were serious. These included acute kidney injury (n = 6), sepsis (n = 2), 1 cardiac event, and 1 pulmonary embolism. Overall, the accuracy of predicting a complication using the ACS NSQIP Risk Calculator was 74% (95% CI, 63%-85%), which was comparable to the accuracy of predicting a complication using only patients' congestive heart failure and pin-tract infection statuses (c = 74%, 95% CI, 62%-86%).

DISCUSSION

Medical optimization of patients with diabetes and multiple medical comorbidities prior to elective complex reconstruction orthopedic surgery allows the surgery to be performed with a predictable risk for perioperative complications. Preoperative anemia and congestive heart failure are associated with longer hospitalizations in this patient group. The ACS NSQIP Risk Calculator appears to be a reliable predictor of complications during the perioperative period. This study demonstrates that reconstructive surgery in this complex patient population can be accomplished with a reasonable exposure to perioperative risk.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Application of stem cell-derived exosomes in ischemic diseases: opportunity and limitations

Ischemic diseases characterized by an insufficient blood flow that leads to a decrease in oxygen and nutrient uptake by cells have emerged as an important contributor to both disability and death worldwide. Up-regulation of angiogenesis may be a key factor for the improvement of ischemic diseases. This article searched articles in PubMed with the following keywords: stem cells, exosomes, angiogenesis, ischemic diseases either alone or in grouping form. The most relevant selected items were stem cell-derived exosomes and ischemic diseases. A growing body of evidence indicates that stem cells produce exosomes, which is the novel emerging approach to cell-to-cell communication and offers a new standpoint on known therapeutic strategies of ischemic diseases. Exosomes transport biological molecules such as many types of proteins, RNAs, DNA fragments, signaling molecules, and lipids between cells. Different stem cells release exosomes representing beneficial effects on ischemic diseases as they promote angiogenesis both in vitro and in vivo experiments. Application of exosomes for therapeutic angiogenesis opened new opportunities in the regenerative medicine, however, some limitations regarding exosomes isolation and application remain concerned. In addition, most of the experiments were conducted in preclinical and therefore translation of these results from bench to bed requires more effort in this field. Exosomes from stem cells are a promising tool for the treatment of ischemic diseases. In addition, translation of pre-clinic results into clinic needs further studies in this field.

Polyphenols: A Promising Avenue in Therapeutic Solutions for Wound Care

In chronic wounds, the regeneration process is compromised, which brings complexity to the therapeutic approaches that need to be adopted, while representing an enormous loss in the patients’ quality of life with consequent economical costs. Chronic wounds are highly prone to infection, which can ultimately lead to septicemia and morbidity. Classic therapies are increasing antibiotic resistance, which is becoming a critical problem beyond complex wounds. Therefore, it is essential to study new antimicrobial polymeric systems and compounds that can be effective alternatives to reduce infection, even at lower concentrations. The biological potential of polyphenols allows them to be an efficient alternative to commercial antibiotics, responding to the need to find new options for chronic wound care. Nonetheless, phenolic compounds may have some drawbacks when targeting wound applications, such as low stability and consequent decreased biological performance at the wound site. To overcome these limitations, polymeric-based systems have been developed as carriers of polyphenols for wound healing, improving its stability, controlling the release kinetics, and therefore increasing the performance and effectiveness. This review aims to highlight possible smart and bio-based wound dressings, providing an overview of the biological potential of polyphenolic agents as natural antimicrobial agents and strategies to stabilize and deliver them in the treatment of complex wounds. Polymer-based particulate systems are highlighted here due to their impact as carriers to increase polyphenols bioavailability at the wound site in different types of formulations.

Glycemic control and diabetic foot ulcer outcomes: A systematic review and meta-analysis of observational studies

OBJECTIVE

To evaluate the association between glycemic control (hemoglobin A1C, fasting glucose, and random glucose) and the outcomes of wound healing and lower extremity amputation (LEA) among patients with diabetic foot ulcers (DFUs).

RESEARCH DESIGN AND METHODS

Medline, EMBASE, Cochrane Library, and Scopus were searched for observational studies published up to March 2019. Five independent reviewers assessed in duplicate the eligibility of each study based on predefined eligibility criteria and two independent reviewers assessed risk of bias. Ameta-analysis was performed to calculate a pooled odds ratio (OR) or hazard ratio (HR) using random effects for glycemic measures in relation to the outcomes of wound healing and LEA. Subgroup analyses were conducted to explore potential source of heterogeneity between studies. The study protocol is registered with PROSPERO (CRD42018096842).

RESULTS

Of 4572 study records screened, 60 observational studies met the study eligibility criteria of which 47 studies had appropriate data for inclusion in one or more meta-analyses(n = 12,604 DFUs). For cohort studies comparing A1C >7.0 to 7.5% vs. lower A1C levels, the pooled OR for LEA was 2.04 (95% CI, 0.91, 4.57) and for studies comparing A1C ≥ 8% vs. <8%, the pooled OR for LEA was 4.80 (95% CI 2.83, 8.13). For cohort studies comparing fasting glucose ≥126 vs. <126 mg/dl, the pooled OR for LEA was 1.46 (95% CI, 1.02, 2.09). There was no association with A1C category and wound healing (OR or HR). There was high risk of bias with respect to comparability of cohorts as many studies did not adjust for potential confounders in the association between glycemic control and DFU outcomes.

CONCLUSIONS

Our findings suggest that A1C levels ≥8% and fasting glucose levels ≥126 mg/dl are associated with increased likelihood of LEA in patients with DFUs. A purposively designed prospective study is needed to better understand the mechanisms underlying the association between hyperglycemia and LEA.

Regenerative and protective effects of dMSC-sEVs on high-glucose-induced senescent fibroblasts by suppressing RAGE pathway and activating Smad pathway

Background

Fibroblasts are crucial for supporting normal wound healing. However, the functional state of these cells is impaired in diabetics because of a high-glucose (HG) microenvironment. Small extracellular vesicles (sEVs) have emerged as a promising tool for skin wound treatment. The aim of this study was to investigate the effects of sEVs derived from human decidua-derived mesenchymal stem cells (dMSC-sEVs) on HG-induced human dermal fibroblast (HDF) senescence and diabetic wound healing and explore the underlying mechanism.

Methods

We first created a HDF senescent model induced by HG in vitro. dMSC-conditioned medium (dMSC-CM) and dMSC-sEVs were collected and applied to treat the HG-induced HDFs. We then examined the proliferation, migration, differentiation, and senescence of these fibroblasts. At the same time, the expressions of RAGE, p21 RAS, Smad2/3, and pSmad2/3 were also analyzed. Furthermore, pSmad2/3 inhibitor (SB431542) was used to block the expression of pSmad2/3 to determine whether dMSC-sEVs improved HDF senescence by activating Smad pathway. Finally, we assessed the effect of dMSC-sEVs on diabetic wound healing.

Results

The HG microenvironment impaired the proliferation, migration, and differentiation abilities of the HDFs and accelerated their senescence. dMSC-CM containing sEVs improved the proliferation and migration abilities of the HG-induced fibroblasts. dMSC-sEVs internalized by HG-induced HDFs not only significantly promoted HDF proliferation, migration, and differentiation, but also improved the senescent state. Furthermore, dMSC-sEVs inhibited the expression of RAGE and stimulated the activation of Smad signaling pathway in these cells. However, SB431542 (pSmad2/3 inhibitor) could partially alleviate the anti-senescent effects of dMSC-sEVs on HG-induced HDFs. Moreover, the local application of dMSC-sEVs accelerated collagen deposition and led to enhanced wound healing in diabetic mice. The detection of PCNA, CXCR4, α-SMA, and p21 showed that dMSC-sEVs could enhance HDF proliferation, migration, and differentiation abilities and improve HDF senescent state in vivo.

Conclusion

dMSC-sEVs have regenerative and protective effects on HG-induced senescent fibroblasts by suppressing RAGE pathway and activating Smad pathway, thereby accelerating diabetic wound healing. This indicates that dMSC-sEVs may be a promising candidate for diabetic wound treatment.

Association between intercellular adhesion molecule 1 (ICAM1) polymorphisms and diabetic foot susceptibility: A case-control study

The objective of the present study was to explore the association between intercellular adhesion molecule 1 (ICAM1) polymorphisms (rs5498 and rs3093030) and diabetic foot (DF) susceptibility in a Chinese Han population.128 type 2 diabetes mellitus (T2DM) patients with DF, 147 T2DM patients without DF, and 155 healthy individuals were enrolled in this study. ICAM1 polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The genotypes and alleles of the polymorphisms were compared by χ test between the 2 groups. Association between ICAM1 polymorphisms and DF susceptibility was expressed through odds ratio (OR) with corresponding 95% confidence interval (95%CI). Effects of ICAM1 polymorphisms on DF clinical characteristics were analyzed by t test.GG genotype of rs5498 polymorphism was distinctly correlated with decreased T2DM risk (OR = 0.369, 95%CI = 0.152-0.895) and reduced susceptibility to DF among healthy controls (OR = 0.316, 95%CI = 0.119-0.837). Similar results were discovered between rs5498 G allele and decreased risk of T2DM (OR = 0.676, 95%CI = 0.475-0.963) and DF (OR = 0.656, 95%CI = 0.453-0.950) among healthy controls. Individuals carrying rs3093030 T allele had low susceptibility to DF developed from T2DM (OR = 0.634, 95%CI = 0.412-0.974). DF patients carrying rs5498 AA genotype had significantly higher serum creatinine levels than GG genotype carriers (P = .003).ICAM1 rs3093030 polymorphism may act as a protective factor against DF developed from T2DM, moreover, rs5498 may be involved in onset of T2DM.Clinical trial number: ChiCTR-INR-18010231.

Low-frequency ultrasound enhances vascular endothelial growth factor expression, thereby promoting the wound healing in diabetic rats

Diabetes is a chronic metabolic disease with a high prevalence worldwide, which typically delays or impairs wound healing, potentially causing death. Low-frequency ultrasound treatment promotes the repair of various injuries and may promote wound healing. The aim of the present study was to determine whether low-frequency ultrasound can accelerate wound healing, as well as investigate its effects on the expression of vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-β1, interleukin (IL)-6 and tumor necrosis factor (TNF)-α in diabetic rats. A total of 45 Wistar rats were intraperitoneally injected with 1% streptozocin following intraperitoneal injection of pentobarbital sodium anesthesia. Subsequently an incision wound was created in the skin of back. The area of the wound was recorded to calculate the rate of wound healing. The expression of VEGF and TGF-β1 was determined via immunohistochemical analysis and their mRNA and protein levels were measured via reverse transcription-quantitative PCR analysis. The results revealed that when compared with the control group, low-frequency ultrasound treatment significantly increased wound healing rate in diabetic rats and markedly increased the mRNA and protein levels of VEGF and TGF-β1. US treatment also reduced the mRNA and protein levels of TNF-α and IL-6. In conclusion, the results of the present study indicated that low-frequency ultrasound promotes the expression of VEGF and TGF-β1, and inhibits the expression of IL-6 and TNF-α, thereby promoting wound healing in diabetic rats.

Therapeutic angiogenesis using stem cell-derived extracellular vesicles: an emerging approach for treatment of ischemic diseases

Ischemic diseases, which are caused by a reduction of blood supply that results in reduced oxygen transfer and nutrient uptake, are becoming the leading cause of disabilities and deaths. Therapeutic angiogenesis is key for the treatment of these diseases. Stem cells have been used in animal models and clinical trials to treat various ischemic diseases. Recently, the efficacy of stem cell therapy has increasingly been attributed to exocrine functions, particularly extracellular vesicles. Extracellular vesicles are thought to act as intercellular communication vehicles to transport informational molecules including proteins, mRNA, microRNAs, DNA fragments, and lipids. Studies have demonstrated that extracellular vesicles promote angiogenesis in cellular experiments and animal models. Herein, recent reports on the use of extracellular vesicles for therapeutic angiogenesis during ischemic diseases are presented and discussed. We believe that extracellular vesicles-based therapeutics will be an ideal treatment method for patients with ischemic diseases.

To Smoke or Not To Smoke: Cigarettes Have a Negative Effect on Wound Healing of Diabetic Foot Ulcers

Diabetic foot ulcers (DFUs) have a complex pathophysiology and require an expert multidisciplinary treatment. There are several, both systemic and local, risk factors for DFUs. A recent meta-analysis of 18 studies has now provided robust evidence on the detrimental effect of smoking on healing of DFUs. Indeed, healing rates were consistently lower among smokers than among nonsmokers. Based on this new evidence, it is reasonable to consider the utility of smoking cessation programs. Incorporation of the latter into the holistic therapeutic strategy for DFUs may be anticipated to improve healing rates, but this remains to be shown.

Association Between Cigarette Smoking and Diabetic Foot Healing: A Systematic Review and Meta-Analysis

The role of smoking for wound healing in patients with diabetic foot has been unclear. This meta-analysis examined the relationship between cigarette smoking and diabetic foot wound healing. Observational studies for the association between smoking and diabetic foot wound healing of patients were systematically searched through PubMed and Wanfang Data, published up to June 2018. Healing rates of wounds were recognized as outcomes. Meta-analysis models were chosen by heterogeneity. A total of 3388 eligible studies were identified, of which 18 met all our inclusion criteria. In the smoking group, healing rate had an average of 62.1%, ranging from 20.0% to 89.6%; in the nonsmoking group, healing rate had an average of 71.5%, ranging from 40.2% to 93.8%. A significant association was found between smoking and the healing of diabetic foot wounds ( z = 3.08; P = .002), with an odds ratio (OR) of 0.70 (95% CI = 0.56-0.88), based on a random-effects model. Meta-regression analyses indicated that the heterogeneity did not come from publication year ( t = -0.50, P = .622) or overall healing rate ( t = 0.16, P = .872). The leave-one-out sensitivity analysis was robust; sensitivity analysis for pooled estimate of adjusted ORs had an OR of 0.20 (95% CI = 0.07-0.56; z = 3.08; P = .002). Subgroup analysis had an OR of 0.62 (95% CI = 0.41-0.95; z = 2.21; P = .027) in retrospective cohort studies and had an OR of 0.75 (95% CI = 0.57-0.99; z = 2.02; P = .043) in prospective cohort studies. Our meta-analysis indicated that smoking had an overall negative effect on the wound healing of diabetic foot individuals. This study provides evidence for the harm of smoking to diabetic foot and may help reduce the medical and economic burden on poor healing of diabetic foot.

Influence of SIRT1 polymorphisms for diabetic foot susceptibility and severity

The present study aimed to explore the influence of sirtuin 1 (SIRT1) polymorphisms (rs12778366 and rs3758391) on diabetic foot (DF) susceptibility and severity in patients with type 2 diabetes mellitus (T2DM).This case-control study recruited 142 patients with DF, 148 patients with T2DM, and 148 healthy controls. SIRT1 gene polymorphisms were sequenced by polymerase chain reaction (PCR) and direct sequencing method. The relative expression of SIRT1 mRNA was estimated using quantitative real-time PCR (qRT-PCR) assay. Odds ratio (OR) with 95% confidence interval (95% CI) were used to represent the association of SIRT1 polymorphisms with DF susceptibility and severity. The results were adjusted using logistic regression analysis.C allele of rs12778366 polymorphism was significantly correlated with reduced DF susceptibility which deriving from healthy controls (adjusted OR = 0.364, 95% CI = 0.158-0.835) so was patients with T2DM (P = .047, OR = 0.591, 95%CI = 0.349-0.998), but the results became nonsignificant adjusted by clinical features (adjusted OR = 0.654, 95% CI = 0.391-1.094). We failed to find any significant association between rs3758391 polymorphisms and T2DM, DF susceptibility. No significant association has been discovered between SIRT1 polymorphisms and DF severity or characteristics. In addition, compared to healthy control and T2DM cases, patients with DF exhibited significant downregulation of SIRT1. The 2 studied polymorphisms had no effects on its gene expression (P > .05 for all).SIRT1 rs12778366 polymorphism C allele might act as a protective factor for DF onset.

Diabetic foot management: multidisciplinary approach for advanced lesion rescue

The diabetic foot is a complication of diabetes affecting 15% of diabetics in their lives. It is associated to diabetic neuropathy and peripheral vascular disease and its incidence has increased. The ulceration is the initial cause of a dramatic process leading, if not correctly treated, to amputations. Both neuropathy, neuro-ischemia and infections have a role in determining healing or worsening of the lesions and 85% of all amputations in diabetic patients are preceded by a foot ulceration deteriorating to a severe gangrene or infection. The different causative agents and the different clinical presentations of diabetic foot ask a multidisciplinary approach in order to address treatments to the final goals, the prevention of the amputations and the maintenance of a functional foot able with weight-bearing ability. Many professional figures, diabetologists, surgeons (both general and vascular and orthopedics), interventional radiologists, infectious diseases specialists, specialized nurses, podiatrists, orthotic technicians, are called to apply their knowledges to the diabetic patients affected by diabetic foot in a virtuous circle leading to reach the goals, with the imperative action of the multidisciplinary team. The so organized center will allow both a correct and rapid diagnosis, the use in ambulatorial environments of modern tools, or the hospitalization in multitasking wards, in which all the complications and the necessary treatments are possible, both in emergencies or in elective way, considering both revascularizations and surgery.