The role of chronic kidney disease as a predictor of outcome after revascularisation of the ulcerated diabetic foot

Impact of acute hyperglycemic crisis episode on survival in individuals with diabetic foot ulcer using a machine learning approach

Objective

The outcome of DFUs concomitant with HCE remains unknown. This study aimed to investigate mortality rates and identify risk factors of mortality in patients with DFUs-HCE.

Methods

27 inpatients with DFUs-HCE were retrospectively enrolled in a cohort design, they were compared to 93 inpatients with DFUs in a city designated emergency center, between January 2016 and January 2021. After a 6-year followed-up, clinical characteristic, amputation and survival rates were compared. Extreme gradient boosting was further used to explore the relative importance of HCE and other risk factors to all-cause mortality in DFUs.

Results

Patients with DFUs-HCE were more likely to havedementia, acute kidney injury and septic shock, whereas DFUs were more likely to have diabetic peripheral neuropathy and ulcer recurrence (P<0.05). No significant difference was observed on the amputation rate and diabetes duration. Both Kaplan-Meier curves and adjusted Cox proportional model revealed that DFUs-HCE was associated with a higher mortality compared with DFUs (P<0.05). HCE significantly increased the risk of mortality in patients with DFUs (hazard ratio, 1.941; 95% CI 1.018-3.700; P = 0.044) and was independent from other confounding factors (age, sex, diabetes duration, Wagner grades and Charlson Comorbidity Index). The XGBoost model also revealed that HCE was one of the most important risk factors associated with all-cause mortality in patients with DFUs.

Conclusions

DFUs-HCE had significantly lower immediate survival rates (first 1-6 month) than DFUs alone. HCE is an important risk factor for death in DFUs patients.

Prognostic models for predicting the risk of foot ulcer or amputation in people with type 2 diabetes: a systematic review and external validation study

AIMS/HYPOTHESIS

Approximately 25% of people with type 2 diabetes experience a foot ulcer and their risk of amputation is 10-20 times higher than that of people without type 2 diabetes. Prognostic models can aid in targeted monitoring but an overview of their performance is lacking. This study aimed to systematically review prognostic models for the risk of foot ulcer or amputation and quantify their predictive performance in an independent cohort.

METHODS

A systematic review identified studies developing prognostic models for foot ulcer or amputation over minimal 1 year follow-up applicable to people with type 2 diabetes. After data extraction and risk of bias assessment (both in duplicate), selected models were externally validated in a prospective cohort with a 5 year follow-up in terms of discrimination (C statistics) and calibration (calibration plots).

RESULTS

We identified 21 studies with 34 models predicting polyneuropathy, foot ulcer or amputation. Eleven models were validated in 7624 participants, of whom 485 developed an ulcer and 70 underwent amputation. The models for foot ulcer showed C statistics (95% CI) ranging from 0.54 (0.54, 0.54) to 0.81 (0.75, 0.86) and models for amputation showed C statistics (95% CI) ranging from 0.63 (0.55, 0.71) to 0.86 (0.78, 0.94). Most models underestimated the ulcer or amputation risk in the highest risk quintiles. Three models performed well to predict a combined endpoint of amputation and foot ulcer (C statistics >0.75).

CONCLUSIONS/INTERPRETATION

Thirty-four prognostic models for the risk of foot ulcer or amputation were identified. Although the performance of the models varied considerably, three models performed well to predict foot ulcer or amputation and may be applicable to clinical practice.

Early outcomes of patients with chronic kidney disease after revascularization for critical limb ischemia

BACKGROUND

The aim of this study was to report early outcomes of patients with non-dialysis-dependent chronic kidney disease (NDD-CKD) after revascularization for critical limb-threatening ischemia (CLTI).

METHODS

Perioperative data of patients from the CRITISCH (critical limb ischemia) Registry, who also had NDD-CKD (stages 3 and 4), were compared to their counterparts with normal renal function (NRF) or mild renal insufficiency (stages 1 and 2). Patient characteristics and type of first-line treatment were assessed. Amputation-free survival was the primary composite endpoint. Secondary endpoints included major adverse cardiovascular and cerebral events (MACCE) and hemodynamic failure of revascularization. Multivariable logistic regression determined risk factors for the endpoints.

RESULTS

424 patients with NDD-CKD were identified. Endovascular revascularization (ER) was performed in 251 patients (59.2%). Eighty-six patients (20.3%) underwent bypass surgery (BS) and 29 patients (6.8%) femoral artery patchplasty (FAP). Conservative treatment (CT) was offered to 46 patients (10.9%); 12 patients (2.8%) underwent primary major amputation (PMA). Logistic regression analysis showed an increased early risk for amputation/death (OR=1.92, 95% CI: 1.09-3.40), death (OR=5.53, 95% CI: 1.92-15.90) and hemodynamic failure of the revascularization (OR=1.80, 95% CI: 1.19-2.72) compared to patients with NRF. Patients with NDD-CKD also seem to carry a higher risk for MACCE (OR=1.82, 95% CI: 0.99-3.36). NDD-CKD was not a risk factor for limb loss alone (OR=1.05, 95% CI: 0.49-2.22).

CONCLUSIONS

NDD-CKD was an independent risk factor for early postoperative mortality, morbidity and reduced patency, but not for limb loss. Robust follow-up is necessary to monitor for such events, as well as to prevent readmission.

Peripheral Artery Disease in Vulnerable Patient Populations: Outcomes of Orbital Atherectomy in Native Americans Compared to Non-Native Americans. A Single-Center Experience in Rural Oklahoma

BACKGROUND/PURPOSE

Although the incidence of peripheral artery disease (PAD) and amputations is higher in Native Americans (NA) than Caucasians, the study of revascularization NA is limited, resulting in their under representation in clinical studies. Orbital atherectomy (OA) is widely utilized for endovascular revascularization of significantly calcified peripheral arteries and has been shown to improve limb salvage rates.

METHODS/MATERIALS

A cohort of 74 consecutive PAD subjects undergoing OA treatment was retrospectively analyzed via Kaplan Meier (KM) and Propensity Score Matched (PSM) analysis.

RESULTS

A significant proportion of the subjects were NA (16.2%). Compared to the non-NA, the NA had higher numerical baseline rates of wounds, dialysis, chronic kidney disease (CKD), and critical limb ischemia, but were numerically less likely to smoke and had similar rates of diabetes. There were very high rates of severe calcification (100% vs. 87%) and pre-procedure diameter stenosis (99% vs. 95%) in both groups. The NA and non-NA had good angiographic outcomes, resulting in low rates of post-procedure residual diameter stenosis (10% vs. 11%). Lastly, KM analysis indicated high freedom from amputation in both groups at 1 year (89% vs. 95%), as well as in the PSM subjects (89% vs. 100%).

CONCLUSIONS

Despite numerically higher rates of co-morbidities at baseline (e.g., CKD, dialysis, and presence of non-healing wounds), the NA underwent successful revascularization with OA, resulting in high freedom from amputation at 1-year. Given the small sample size of NA, these results may not be generalizable-thus, larger studies on NA are warranted.

Critical limb ischemia: current challenges and future prospects

Critical limb ischemia (CLI) is considered the most severe pattern of peripheral artery disease. It is defined by the presence of chronic ischemic rest pain, ulceration or gangrene attributable to the occlusion of peripheral arterial vessels. It is associated with a high risk of major amputation, cardiovascular events and death. In this review, we presented a complete overview about physiopathology, diagnosis and holistic management of CLI. Revascularization is the first-line treatment, but several challenging cases are not treatable by conventional techniques. Unconventional techniques for the treatment of complex below-the-knee arterial disease are described. Furthermore, the state-of-the-art on gene and cell therapy for the treatment of no-option patients is reported.

Signal reduction of donor artery on MRI after superficial temporal artery to middle cerebral artery anastomosis: a retrospective analysis

OBJECT

Microsurgical anastomosis from the superficial temporal artery (STA) to the middle cerebral artery (MCA) is a treatment option for appropriately selected patients with cranial atherosclerotic steno-occlusive disease (CASD). However, the long-term efficacy and patency of the donor artery remain unclear. We reviewed the signal intensity of the donor artery on magnetic resonance angiography (MRA) after STA-MCA anastomosis in patients with CASD and clarified the incidence of and risk factors for reduction in postoperative signal of STA.

METHODS

From April 2007 to March 2015, 155 STA-MCA anastomosis operations for CASD were performed at our institute. The postoperative imaging findings of 112 patients with available follow-up data for more than 3 months were retrospectively reviewed.

RESULTS

Over a median follow-up of 24 months, the signal of the donor artery on MRA became weaker than that on MRA performed immediately after surgery in 30 (27%) patients. The rates of signal reduction at 1 and 2 years after surgery were 18 and 25%, respectively. Multivariate analysis revealed that a high STA bifurcation (p = 0.015; odds ratio, 7.14) and the presence of chronic kidney disease (p = 0.011; odds ratio, 5.59) were independent risk factors for postoperative signal reduction.

CONCLUSIONS

Our results suggest that the signal intensity of the donor artery of an established STA-MCA bypass decreases in many cases. Both the loose entrance of the STA to the dura and systemic atherosclerosis are related to postoperative vessel remodeling.

Great toe necrosis predicts an unfavorable limb salvage prognosis

Summary:

The initial location of necrosis may affect the limb salvage rate. This study of 130 patients with chronic toe ulcers or gangrene was performed to assess whether the location of initial necrosis in the toes affected limb salvage prognosis. The patients were divided into 2 groups according to whether the initial necrosis was in the great toe or in other toes. Limb salvage prognosis was determined retrospectively. In the great toe group, the rates of total toe loss and major amputation were 50.0% and 24.4%, respectively. When the initial necrosis was in other toes, these rates were 27.3% and 9.3%, respectively. Great toe necrosis is associated with significantly higher rates of total toe loss (odds ratio = 3.10; P = 0.003; 95% confidence interval, 1.43−6.68) and major amputation (odds ratio = 3.66; P = 0.007; 95% confidence interval, 1.37−9.79). The great toe is supplied by 3 source arteries, whereas the lesser toes are fed by 1 or 2 arteries. Therefore, necrosis initiating from the great toe may reflect the presence of severe vascular disorders. The great toe is also anatomically connected to much of the foot via the tendons. Infection is more likely to spread along these tendons, which may reduce limb prognosis. Thus, the initial location of necrosis may be predictive of limb prognosis.

Neutrophil-lymphocyte ratio as a prognostic marker of outcome in infrapopliteal percutaneous interventions for critical limb ischemia

BACKGROUND

Endovascular intervention has become a frequently used treatment of critical limb ischemia (CLI) in recent times. The recent Bypass vs Angioplasty in Severe Ischaemia of the Leg (BASIL) trial consensus recommended endovascular treatment as a first-line treatment in patients who have a life expectancy that was limited to <2 years. Despite these recommendations, there still remains limited data available to clinicians when seeking to risk stratify patients who present with CLI. The neutrophil-lymphocyte ratio (NLR) has been suggested to be a marker for predicting mortality and patency. This study aimed to investigate the use of the NLR as a prognostic marker for primary patency and mortality after an infrapopliteal endovascular intervention in patients with CLI.

METHODS

All patients who underwent tibial angioplasty for CLI were retrospectively analyzed. Demographics, degrees of stenosis, vessel patency rates, mortality, and comorbidities were recorded. NLRs were calculated from preoperative blood samples. Primary end points were all-cause mortality, primary patency, and amputation-free survival (AFS) within the follow-up period of 12 months. Multivariate Cox proportional hazard models were used to identify independent predictors. Overall survival, AFS, and the probability of a vessel remaining patent were evaluated by standard Kaplan-Meier survival curves and groups compared by the log-rank test.

RESULTS

Eighty-three patients were monitored for 12 months. Ninety limbs were identified, with 104 procedural events and 127 vessels undergoing successful angioplasty. The technical success rate was 86%, and patency at 1 year was 19%. Survival at 1 year was 76% and AFS was 61%. Patients with a NLR ≥5.25 had an increased risk of death (hazard ratio, 1.97; 95% confidence interval, 1.08-3.62; P = .03) compared with those with a NLR of <5.25. Furthermore, those with lymphocytes counts of <1.5 × 10(9)/L had higher mortality (hazard ratio, 1.88; 95% confidence interval, 1.02-3.70; P = .045) than those with lymphocyte counts >1.5 × 10(9)/L.

CONCLUSIONS

The NLR and absolute lymphocyte counts are potentially valuable prognostic indicators for risk stratification of patient's presenting with CLI undergoing infrapopliteal angioplasty.

Treatment of peripheral arterial disease in diabetes: a consensus of the Italian Societies of Diabetes (SID, AMD), Radiology (SIRM) and Vascular Endovascular Surgery (SICVE)

Diabetic foot (DF) is a chronic and highly disabling complication of diabetes. The prevalence of peripheral arterial disease (PAD) is high in diabetic patients and, associated or not with peripheral neuropathy (PN), can be found in 50% of cases of DF. It is worth pointing out that the number of major amputations in diabetic patients is still very high. Many PAD diabetic patients are not revascularised due to lack of technical expertise or, even worse, negative beliefs because of poor experience. This despite the progress obtained in the techniques of distal revascularisation that nowadays allow to reopen distal arteries of the leg and foot. Italy has one of the lowest prevalence rates of major amputations in Europe, and has a long tradition in the field of limb salvage by means of an aggressive approach in debridement, antibiotic therapy and distal revascularisation. Therefore, we believe it is appropriate to produce a consensus document concerning the treatment of PAD and limb salvage in diabetic patients, based on the Italian experience in this field, to share with the scientific community.

Comparative effectiveness of endovascular and surgical revascularization for patients with peripheral artery disease and critical limb ischemia: systematic review of revascularization in critical limb ischemia

BACKGROUND

For patients with critical limb ischemia (CLI), the optimal treatment to enhance limb preservation, prevent death, and improve functional status is unknown. We performed a systematic review and meta-analysis to assess the comparative effectiveness of endovascular revascularization and surgical revascularization in patients with CLI.

METHODS

We systematically searched PubMed, Embase, and the Cochrane Database of Systematic Reviews for relevant English-language studies published from January 1995 to August 2012. Two investigators screened each abstract and full-text article for inclusion, abstracted the data, and performed quality ratings and evidence grading. Random-effects models were used to compute summary estimates of effects, with endovascular treatment as the control group.

RESULTS

We identified a total of 23 studies, including 1 randomized controlled trial, which reported no difference in amputation-free survival at 3 years (odds ratio [OR] 1.22, 95% CI 0.84-1.77) and all-cause mortality (OR 1.07, 0.73-1.56) between the 2 treatments. Meta-analysis of the observational studies showed a statistically nonsignificant reduction in all-cause mortality at 6 months (11 studies, OR 0.85, 0.57-1.27) and amputation-free survival at 1 year (2 studies, OR 0.76, 0.48-1.21) in patients treated with endovascular revascularization. There was no difference in overall death, amputation, or amputation-free survival at ≥2 years.

CONCLUSIONS

The currently available literature suggests that there is no difference in clinical outcomes for patients with CLI treated with endovascular or surgical revascularization. There is a paucity of high-quality data available to guide clinical decision making, especially as it pertains to patient subgroups or anatomical considerations.

Therapeutic angiogenesis in critical limb ischemia

Critical limb ischemia (CLI) is a severe form of peripheral artery disease associated with high morbidity and mortality. The primary therapeutic goals in treating CLI are to reduce the risk of adverse cardiovascular events, relieve ischemic pain, heal ulcers, prevent major amputation, and improve quality of life (QoL) and survival. These goals may be achieved by medical therapy, endovascular intervention, open surgery, or amputation and require a multidisciplinary approach including pain management, wound care, risk factors reduction, and treatment of comorbidities. No-option patients are potential candidates for the novel angiogenic therapies. The application of genetic, molecular, and cellular-based modalities, the so-called therapeutic angiogenesis, in the treatment of arterial obstructive diseases has not shown consistent efficacy. This article summarizes the current status related to the management of patients with CLI and discusses the current findings of the emerging modalities for therapeutic angiogenesis.

Meta-analysis of contemporary short- and long-term mortality rates in patients diagnosed with critical leg ischaemia

BACKGROUND

Critical leg ischaemia (CLI) has been associated with high mortality rates. There is a lack of contemporary data on both short- and long-term mortality rates in patients diagnosed with CLI.

METHODS

This was a systematic literature search for studies prospectively reporting mortality in patients diagnosed with CLI. Meta-analysis and meta-regression models were developed to determine overall mortality rates and specific patient-related factors that were associated with death.

RESULTS

A total of 50 studies were included in the analysis The estimated probability of all-cause mortality in patients with CLI was 3·7 per cent at 30 days, 17·5 per cent at 1 year, 35·1 per cent at 3 years and 46·2 per cent at 5 years. Men had a statistically significant survival benefit at 30 days and 3 years. The presence of ischaemic heart disease, tissue loss and older age resulted in a higher probability of death at 3 years.

CONCLUSION

Early mortality rates in patients diagnosed with CLI have improved slightly compared with previous historical data, but long-term mortality rates are still high.

Endovascular Treatment for Infrainguinal Vessels in Patients With Critical Limb Ischemia

Background—

Recent technical advances have made endovascular treatment (EVT) an alternative first-line treatment for critical limb ischemia.

Methods and Results—

A prospective multicenter study was conducted to evaluate the clinical outcomes of 314 Japanese critical limb ischemia patients (mean age, 73±10 years) with infrainguinal arterial lesions who underwent EVT. Patients were enrolled from December 2009 to July 2011 and were followed-up for 12 months. The primary end point was amputation-free survival (AFS) at 12 months. Secondary end points were anatomic, clinical, and hemodynamic measures, including 12-month freedom from major adverse limb events. The 12-month AFS rate was 74%, with body mass index <18.5 (hazard ratio [HR], 2.22; P =0.008), heart failure (HR, 1.73; P =0.04), and wound infection (HR, 1.89; P =0.03) associated with a poor prognosis for AFS. The 12-month major adverse limb event-free rate was 88%, with hemodialysis (HR, 1.98; P =0.005), heart failure (HR, 1.69; P =0.02), and Rutherford classification 6 (HR, 2.25; P =0.002) associated with a poor prognosis for major adverse limb events. The median time for wound healing was 97 days, with body mass index <18.5 (HR, 0.54; P =0.03) and wound infection (HR, 0.60; P =0.04) being significant risk factors for unhealed wounds after EVT. At 12 months, 34% had undergone reintervention (bypass surgery, 2.6%; repeat EVT, 31.7%), and 73% were major adverse event–free.

Conclusions—

The high reintervention rate notwithstanding, EVT was an effective treatment for Japanese critical limb ischemia patients with infrainguinal disease, with satisfactory AFS and major adverse limb event-free rates. The results of this study will be helpful for the future evaluation of critical limb ischemia therapy.

Clinical Trial Registration—

URL: http://www.umin.ac.jp/ctr . Unique identifier: UMIN000002830.

Renal failure: implications of chronic kidney disease in the management of the diabetic foot

Foot complications are common in patients with diabetes, however, chronic kidney disease has emerged as an independent risk factor for development of foot lesions in the diabetic population. Apart from peripheral arterial disease, infection, and neuropathy, which are classic factors contributing to development of foot lesions, skin disorders specific to renal failure, impaired wound healing from uremia, and psychosocial issues offer further compounded risk. Consequently, there are high ulceration and amputation rates that are associated with increased morbidity and mortality. In recent studies, foot-care programs with a multidisciplinary approach within dialysis units have demonstrated improved outcomes.

Chapter V: Diabetic foot

Ulcerated diabetic foot is a complex problem. Ischaemia, neuropathy and infection are the three pathological components that lead to diabetic foot complications, and they frequently occur together as an aetiologic triad. Neuropathy and ischaemia are the initiating factors, most often together as neuroischaemia, whereas infection is mostly a consequence. The role of peripheral arterial disease in diabetic foot has long been underestimated as typical ischaemic symptoms are less frequent in diabetics with ischaemia than in non-diabetics. Furthermore, the healing of a neuroischaemic ulcer is hampered by microvascular dysfunction. Therefore, the threshold for revascularising neuroischaemic ulcers should be lower than that for purely ischaemic ulcers. Previous guidelines have largely ignored these specific demands related to ulcerated neuroischaemic diabetic feet. Any diabetic foot ulcer should always be considered to have vascular impairment unless otherwise proven. Early referral, non-invasive vascular testing, imaging and intervention are crucial to improve diabetic foot ulcer healing and to prevent amputation. Timing is essential, as the window of opportunity to heal the ulcer and save the leg is easily missed. This chapter underlines the paucity of data on the best way to diagnose and treat these diabetic patients. Most of the studies dealing with neuroischaemic diabetic feet are not comparable in terms of patient populations, interventions or outcome. Therefore, there is an urgent need for a paradigm shift in diabetic foot care; that is, a new approach and classification of diabetics with vascular impairment in regard to clinical practice and research. A multidisciplinary approach needs to implemented systematically with a vascular surgeon as an integrated member. New strategies must be developed and implemented for diabetic foot patients with vascular impairment, to improve healing, to speed up healing rate and to avoid amputation, irrespective of the intervention technology chosen. Focused studies on the value of predictive tests, new treatment modalities as well as selective and targeted strategies are needed. As specific data on ulcerated neuroischaemic diabetic feet are scarce, recommendations are often of low grade.

The ulcerated leg: when to revascularize

The role of peripheral arterial disease in ulcerated diabetic feet has long been underestimated. Progressive claudication, rest pain and the extent of irreversible tissue loss have frequently been indications for revascularization for neuroischaemic ulcers in diabetic patients. These typical ischaemic symptoms are warning signs that are less frequent in diabetic individuals with ischaemia than those without diabetes. Consequently, 30-50% of individuals with diabetes and foot ulcers already have gangrene at admission and are therefore often considered unsuitable for revascularization. Furthermore, the healing of a neuroischaemic ulcer is worsened by microvascular dysfunction, causing arteriovenous shunting, capillary ischaemia, leakage and venous pooling. Therefore, the threshold of revascularizing neuroischaemic ulcers should be lower than that of purely ischaemic ulcers. Comorbidity, ulcer characteristics and infection affect the decision as to when to intervene, as do the severity and extent of occlusive arterial lesions. The window of opportunity for vascular intervention in the neuroischaemic diabetic foot should not be missed, and the need for early vascular intervention as an integrated part of a strategy to achieve healing should be emphasized. Noninvasive vascular testing should be performed on all individuals with an ulcerated diabetic foot. The arterial tree should be imaged if noninvasive tests indicate ischaemia or when mild or questionable ischaemia is diagnosed and conservative treatment does not promote ulcer healing in 6 weeks. Revascularization should be performed whenever feasible to repair distal perfusion to achieve ulcer healing.

Peripheral arterial disease in diabetic patients with renal insufficiency: a review

Peripheral arterial disease is common among diabetic patients with renal insufficiency, and most of the diabetic patients with end-stage renal disease (ESRD) have peripheral arterial disease. Ischaemia is probably overrepresented as an etiological factor for a diabetic foot ulcer in this group of patients compared with other diabetic patients. ESRD is a strong risk factor for both ulceration and amputation in diabetic patients. It increases the risk of nonhealing of ulcers and major amputation with an OR of 2.5-3. Renal disease is a more important predictor of poor outcome after revascularizations than commonly expected. Preoperative vascular imaging is also affected by a number of limitations, mostly related to side effects of contrast agents poorly eliminated because of kidney dysfunction. Patients with renal failure have high perioperative morbidity and mortality. Persistent ischaemia, extensive infection, forefoot and heel gangrene, poor run-off, poor cardiac function, and the length of dialysis-dependent renal failure all affect the outcome adversely. Despite dismal overall outcome, recent data indicate that by proper selection, favourable results can be obtained even in ESRD patients, with the majority of studies reporting 1-year limb salvage rates of 65-75% after revascularization among survivors. High 1-year mortality of 38% reported in a recent review has to be taken into consideration, though. The preferential use of endovascular-first approach is attractive in this vulnerable multimorbid group of patients, but the evidence for endovascular treatment is very scarce. The need for complete revascularization of the foot may be even more important than in other patients with ischaemic ulcerated diabetic foot because there are a number of factors counteracting healing in these patients. Typically, half of the patients are reported to lose their legs despite open bypass. To control tissue damage and improve chances of ulcer healing, one should understand that early referral to vascular consultation is necessary.