Prognosis of critical limb ischemia: Major vs. minor amputation comparison

Effect of down-regulation of let-7c/g on triggering a double-negative feedback loop and promoting restenosis

BACKGROUND

Excessive proliferation and migration of vascular smooth muscle cells (VSMCs) are the main causes of restenosis (RS) in diabetic lower extremity arterial disease (LEAD). However, the relevant pathogenic mechanisms are poorly understood.

METHODS

In this study, we introduced a "two-step injury protocol" rat RS model, which started with the induction of atherosclerosis (AS) and was followed by percutaneous transluminal angioplasty (PTA). Hematoxylin-eosin (HE) staining and immunohistochemistry staining were used to verify the form of RS. Two-step transfection was performed, with the first transfection of Lin28a followed by a second transfection of let-7c and let-7g, to explore the possible mechanism by which Lin28a exerted effects. 5-ethynyl-2΄-deoxyuridine (EdU) and Transwell assay were performed to evaluate the ability of proliferation and migration of VSMCs. Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) were performed to detect the expression of Lin28a protein and let-7 family members.

RESULTS

Using a combination of in vitro and in vivo experiments, we discovered that let-7c, let-7g, and microRNA98 (miR98) were downstream targets of Lin28a. More importantly, decreased expression of let-7c/let-7g increased Lin28a, leading to further inhibition of let-7c/let-7g. We also found an increased level of let-7d in the RS pathological condition, suggesting that it may function as a protective regulator of the Lin28a/let-7 loop by inhibiting the proliferation and migration of VSMCs.

CONCLUSION

These findings indicated the presence of a double-negative feedback loop consisting of Lin28a and let-7c/let-7g, which may be responsible for the vicious behavior of VSMCs in RS.

Effects of Anesthetic Techniques on the Risk of Postoperative Complications Following Lower Extremity Amputation in Diabetes Patients with Coagulation Abnormalities: A Retrospective Cohort Study Using Propensity Score Analysis

Diabetic foot amputation is associated with high morbidity and mortality rates. To prevent cardiovascular complications along with vasculopathy in the course of diabetes mellitus, a high number of patients receive anticoagulant therapy. However, anticoagulants are contraindicated in neuraxial anesthesia limiting available anesthetic modalities. Therefore, in this retrospective study, we aimed to compare between general anesthesia and peripheral nerve block (PNB) with respect to postoperative complications following lower extremity amputation (LEA) in patients with coagulation abnormalities. In total, 320 adult patients who underwent LEA for diabetic foot were divided into two groups according to the anesthetic type (general anesthesia vs. PNB). The inverse probability of treatment weighting was performed to balance the baseline patient characteristics and surgical risk between the two groups. The adjusted analysis showed that compared with the general anesthesia group, the PNB group had lower risks of pneumonia (odds ratio: 0.091, 95% confidence interval [CI]: 0.010-0.850, p = 0.0355), acute kidney injury (odds ratio: 0.078, 95% CI: 0.007-0.871, p = 0.0382), and total major complications (odds ratio: 0.603, 95% CI: 0.400-0.910, p = 0.0161). Additionally, general anesthesia was associated with a higher amount of intraoperative crystalloid administration and a requirement for more frequent vasopressors. In conclusion, PNB appears to be protective against complications following LEA in diabetes patients with coagulopathy.

A meta-analysis of mortality after minor amputation among patients with diabetes and/or peripheral vascular disease

OBJECTIVE

Foot complications in patients with diabetes or peripheral artery disease (PAD) are serious events in the life of these patients that often lead to amputations and mortality. No evidence synthesis has been reported on the mortality rates after minor lower extremity amputation; thus, a quantitative evidence synthesis was needed.

METHODS

A systematic literature search was performed to identify studies that had reported the survival or mortality rates after a minor LEA. The studies were required to include one or more of the following primary outcomes: mortality rate at 30 days, 1 year, 3 years, 5 years, 6 to 7 years, or 8 to 9 years. The secondary outcomes were the mortality rates according to the anatomic location of the amputation in the foot and the independent risk factors for mortality.

RESULTS

A total of 28 studies with 17,325 subjects fulfilled the inclusion criteria. The meta-analytical results of the mortality rates were as follows: 3.5% at 1 month, 20% at 1 year, 28% at 3 years, 44.1% at 5 years, 51.3% at 6 to 7 years, and 58.5% at 8 to 9 years. From these studies of diabetic patients, age was the most consistent independent risk factor, followed by chronic kidney disease, PAD, and coronary artery disease. One study of patients with PAD had reported diabetes as an independent risk factor for mortality. The subgroup analysis of the four studies reporting the outcomes of patients with PAD showed greater 3- and 5-year mortality rates compared with the overall and "diabetic" results.

CONCLUSIONS

Mortality after minor amputation for patients with diabetes and/or PAD was found to be very high. Compared with the reported cancer data, survival was worse than that for many cancers. Just as in the case of major amputations, minor amputations should be considered a pivotal event in the life of these patients.

The efficacy of negative pressure wound therapy for diabetic foot ulcers: A systematised review

AIM

This review investigated the current state of knowledge on negative pressure wound therapy (NPWT) used to treat diabetic foot ulceration (DFU), its clinical effectiveness and any current issues in the research. NICE have recommended research into the clinical effectiveness of different dressing types for DFUs since 2015.

METHODS

A systematic search of the British Nursing Index, CINAHL, Cochrane Central and PubMed was undertaken. Only primary studies were included and studies investigating a combination of NPWT and other therapies were excluded. All the included studies were published in English between 2008 and 2018 and were peer reviewed.

RESULTS

The search yielded seven studies for inclusion in the qualitative analysis. The studies included a variety of methodologies specifically; 3 randomized controlled trials, 2 case series', 1 non-controlled trial and 1 randomized case-control study. Three main themes were identified and formed the focus of the qualitative synthesis.

DISCUSSION

All the included studies reported that NPWT led to better clinical outcomes when compared to standard treatment. However, the studies had numerous methodological flaws such as the absence of validated tools for the measurement of outcomes such as wound area and depth; a lack of statistical power calculations to determine adequate sample sizes or the significance of outcome measures. Additionally, there was little consistency in the pressures used for the NPWT devices. Finally, many of the controlled trials did not conform to the standard of reporting trials stipulated by the CONSORT statement.

Inflammatory biomarkers, vascular procedures of lower limbs, and wound healing

Abnormal, persistent inflammation after bypass surgery could prevent healing of an ischaemic foot lesion. In 37 patients with peripheral arterial disease (PAD) (Rutherford Grade III Category 5) who underwent infrapopliteal vein graft and midfoot amputation, plasma levels of fibrinogen, C-reactive protein (CRP), interleukin-1 (IL-1), interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), and matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9) were determined preoperatively and during the follow up. Nine patients without clinical and Doppler evidence of arterial disease, who underwent post-traumatic midfoot primary amputation, were included in the experiment group, and 15 age-matched healthy volunteers served as control. In patients who had midfoot amputation for trauma, all wounds healed. Seven (19%) wounds in patients with an occluded graft healed, and five (13%) required major amputation because of a non-healing wound. Time required for complete healing of the lesion was similar between trauma and PAD patients (8 ± 2 months vs 11 ± 6, respectively, P = NS). Univariate analysis demonstrated that, in PAD patients, the postoperative high levels of TNF-α, IL-6, and MMP-2 and -9 were predictive for wound healing failure at 3, 6, and 9 months (P < 0.05), respectively. Furthermore, the subgroup of patients who experienced occlusion of the vein graft during follow up had a significant increase of MMP-2, -9, IL-6, and TNF-α at 3, 6, and 9 months (P < 0.05), respectively. Monitoring inflammatory markers allows the determination of patients at risk of healing failure of midfoot amputation after distal revascularisation and might predict the fate of the vein graft.

Clinical outcomes among morbidly obese patients hospitalized with diabetic foot complications

The aim of the study is to investigate effects of morbid obesity on patients hospitalized with diabetic foot ulcers and infections (DFU/Is). This retrospective cohort study of hospitalized adults investigated patients with a principal diagnosis of DFU/Is, and compared outcomes based on weight. The primary outcome was lower limb amputations. Secondary outcomes included in-hospital mortality, morbidity (sepsis and discharge disposition), resource utilization (length of stay [LOS] and total hospitalization charges). Multivariate analyses adjusted for confounders. A total of 31 730 admissions were included; 14% were morbidly obese. Patients with morbid obesity had overall lower rates of amputations (adjusted odds ratio [aOR]: 0.60; 95% confidence interval [CI]: 0.45-0.80). There was no difference in mortality rates between those who were morbidly obese and the non-morbidly obese patients (aOR: 3.89 [95% CI: 0.79-19.30]). Combined data from 2010 to 2014 have found higher odds of sepsis in morbidly obese patients compared with non-morbidly obese patients after adjusting for confounders (aOR: 1.49 [1.09-2.02], P = 0.01). Patients with morbid obesity were less likely to be discharged to home (aOR: 0.82 [95% CI: 0.70-0.95]), had longer LOS (adjusted mean difference [aMD]: 0.47 [95% CI: 0.13-0.81]) and higher hospital charges (aMD: $3205 [95% CI: $3373-$6037]). Despite having lower amputation rates compared to those who are not morbidly obese, patients with morbid obesity hospitalized for DFU/Is succumbed to sepsis more frequently and had less favourable utilization metrics. Specialized care pathways may be needed to enhance the value of care delivered to this high-risk population.

Evaluation of skin perfusion pressure to assess refractory foot ulcers

OBJECTIVE

The number of patients with foot gangrene caused by critical ischaemia and severe infection is increasing significantly in developed countries. The measurement of perilesional skin blood flow by skin perfusion pressure (SPP) is useful to select the appropriate treatment of gangrenous lesions, in that it is not affected by calcifications of blood vessels. However, the prognosis of a foot ulcer may also be affected by the level of blood sugar and infections. This study aimed to validate the use of SPP in cases of foot gangrene and ulcers in patients with and without diabetes mellitus (DM) and infection.

METHOD

Clinical symptoms, ankle-brachial pressure index (ABPI) and SPP were assessed to evaluate the condition of each foot ulcer. Every foot ulcer was treated as independent, even if a participant had multiple ulcers. All ulcers for which we measured SPP were subject to the analysis. All ulcers were purely ischaemic in nature and were exclusively located on the foot or toes.

RESULTS

Data were collected from 117 foot ulcers on 91 toes and feet from 65 patients. Almost all SPP values in healed cases were > 27 mmHg. There were three patients whose ulcers failed to heal by conservative treatments were complicated with severe infection. However, no effect of DM on the relationship between SPP values and prognosis was observed. Logistic regression analysis of all ulcers except for the 5 cases complicated with infection revealed that those with 30 mmHg or lower SPP values are likely to heal by conservative treatment with 23% or lower probability, whereas any ulcer with more than 50 mmHg SPP value and without severe infection may heal without the need for further operations with 80% or higher probability.

CONCLUSION

The combination of SPP and careful evaluation of infection may be a good parameter to decide the appropriate treatment for ischaemic skin ulcers, regardless of the complication of DM.

The Geriatric Nutritional Risk Index Independently Predicts Mortality in Diabetic Foot Ulcers Patients Undergoing Amputations

Objective. Patients with diabetic foot ulcers undergoing amputations have poor prognosis. Malnutrition usually occurs in this population and is associated with increased risk of mortality. The geriatric nutritional risk index (GNRI) is a widely used, simple, and well-established tool to assess nutritional risk. The purpose of this study was to assess the association between GNRI and all-cause mortality in diabetic foot ulcers patients undergoing minor or major amputations. Methods. This was a retrospective cohort study including 271 adult patients. Patients were divided into two groups according to a GNRI cutoff value of 92, and characteristics and mortality were compared between the two groups. Cox proportional hazard analysis was performed to explore the association between GNRI and mortality. Result. GNRI (p < 0.001), age (p < 0.001), and eGFR (p = 0.002) were independent predictors of mortality. Among a subgroup of 230 patients with minor amputation, increased age (p < 0.001), coronary artery disease (p = 0.030), and increased GNRI (p < 0.001) were major risk factors. Conclusion. GNRI on admission might be a novel clinical predictor for the incidence of death in patients with diabetic foot ulcers who were undergoing amputations.

Comparison of mortality rates and functional results after transtibial and transfemoral amputations due to diabetes in elderly patients-a retrospective study

INTRODUCTION

This study aimed to compare mortality rates and functional results of transtibial and transfemoral amputations in elderly patients with diabetes.

METHODS

87 amputees [54 (62.1%) transtibial and 33 (37.9%) transfemoral] were included. Mean ages were 70.7 and 69.3 years in transfemoral and transtibial groups, respectively. Mean follow up time was 41.8 months. Amputee Mobility Predictor scores (with and without prosthesis) and Barthel Daily Living Index were used for functional evaluation of the survivors.

RESULTS

First year mortality rates were 29.6% and 30.3% in transtibial and transfemoral groups, respectively. Overall mortality rate of both groups was 65.5% (66.7% in transtibial and 63.6% in transfemoral group). There was no difference between mortality rates of two groups. Duration between surgery and death was significantly shorter in transfemoral group. The mean Amputee Mobility Predictor scores (with prosthesis) of the transtibial and transfemoral groups were 32.3 and 26.9 points, respectively. The average Amputee Mobility Predictor scores (without prosthesis) of the transtibial and transfemoral groups were 29.5 and 22.7 points respectively. The differences between two groups' scores were significant. The mean Barthel Daily Living Index scores of the transtibial and transfemoral groups were 82.5 and 80.2 points respectively. The difference was not significant.

CONCLUSIONS

High mortality rates and morbidities after major lower limb amputations emphasize the importance of preventive measures and foot care in patients with diabetes.