Chronic kidney disease predicts long-term mortality after major lower extremity amputation

Outcomes following Deep Venous Arterialization in Medicare patients with Chronic Limb Threatening Ischemia

OBJECTIVES

Despite advances in the management of chronic limb-threatening ischemia (CLTI), a large proportion of these patients are not candidates for traditional revascularization and may be destined for major amputation. Given this medically complex and "no-option" patient population, deep venous arterialization (DVA) has recently been revitalized as a limb salvage technique whereby an arteriovenous fistula in the lower leg is created to supply more oxygenated blood via the venous system to the foot. The recent PROMISE II trial demonstrated a 6-month amputation-free survival (AFS) rate of 66% following DVA. With this trial in mind, our study aims to evaluate the real-world outcomes of this procedure.

METHODS

The study population included all patients undergoing a DVA from January 1, 2021 through December 31, 2023 among fee-for-service (FFS) beneficiaries identified in the Medicare FFS Carrier Claims file. DVA procedures were identified using CPT 0620T. Outcomes included limb salvage, freedom from major adverse limb events (MALE; defined as major amputation or ipsilateral re-intervention), survival, and AFS. Cumulative incidences for outcomes that include death were estimated from traditional Kaplan-Meier methods; for non-death endpoints, outcomes were estimated from the cumulative incidence function, accounting for the competing risk of death.

RESULTS

Between 2021 and 2023, 134 patients underwent a DVA for CLTI. Among these, the median age was 70 years and the majority of patients were male (66%), white (63%), had tissue loss (72%), hypertension (99%), hyperlipidemia (96%), chronic kidney disease (89%), and diabetes (83%). Following a DVA for CLTI, six-month and one-year AFS incidences were 42% and 33%, respectively. One-year incidences of limb salvage, freedom from MALE, and survival were 53%, 36%, and 65%, respectively.

CONCLUSIONS

Among patients with no traditional options for revascularization, our data demonstrate that DVA is a procedure that is, by its nature, performed in high-risk individuals who continue to have a high risk of limb loss and mortality. Importantly, AFS in our analysis is notably worse than that reported in PROMISE II and, as such, raises questions about the generalizability of this procedure in real world practice. Further investigation is needed regarding patient selection criteria for and the clinical utility of the DVA procedure.

Increased Risk of End-Stage Kidney Disease After Traumatic Amputation: Nationwide Cohort Study

BACKGROUND

Amputation confers disabilities upon patients and is associated with substantial cardiovascular and metabolic morbidity and mortality. We aimed to compare the incidence of end-stage kidney disease (ESKD) between individuals with amputation and the general population.

METHODS

A population-based retrospective cohort study was performed using the Nationwide Health Insurance Service database for the period between 2010 and 2018. A total of 24,925 individuals with amputation were included with a ratio of 1:3 age- and sex-matched controls. A Cox proportional hazards regression analysis was used to calculate the risk of ESKD among amputees.

RESULTS

During a mean follow-up period of 4.3 years, there were 40 incident ESKD cases (0.4 per 1000 person-years) among individuals with amputation. Individuals with amputation showed a higher risk of ESKD (adjusted HR [aHR] of 1.75, 95% confidence interval [CI] of 1.20-2.54) compared with matched controls. The risk was further increased in those with mild disability (aHR of 1.41, 95% CI of 0.51-3.87) and severe disability (aHR of 8.22, 95% CI of 2.99-22.61). When considering the levels of amputation, the association was apparently more prominent in proximal than distal amputation, in particular for proximal upper limb amputation (aHR of 17.90, 95% CI of 4.37-73.40).

CONCLUSIONS

Individuals with amputation were at a significantly greater risk of ESKD than the general population, particularly subjects with severe disability and proximal amputation. Our data suggest that amputations should be added to the list of risk factors for the development of chronic kidney disease.

Lower extremity amputation rates in patients with chronic kidney disease: A database study comparing patients with and without diabetes mellitus

Lower extremity amputation (LEA) is one of the most feared consequences of diabetes mellitus (DM). The purpose of this study was to evaluate the impact of DM on LEA rates in patients at various stages of chronic kidney disease (CKD). A commercially available de-identified database was searched for patients undergoing LEA and for CKD patients, from 2010 to 2023. Patients with DM and patients without DM who were followed for at least 5 years were included. LEA rates were then compared for patients at all 5 CKD stages in patients with and without diabetes. Rates of all LEA were found to be significantly higher at all CKD stages for patients with diabetes (overall, minor and major LEA). Compared to patients without DM who have CKD stage 5 (end stage renal disease), patients with DM and CKD stage 5 have a 30 fold increased likelihood of undergoing overall LEA [OR 30.2 (24.48-37.19), p < 0.001], 29 fold increased likelihood of undergoing minor LEA [28.9i (22.91-36.35), p < 0.001] and 40 times fold increased likelihood of undergoing major LEA [40.1 (26.59-60.42), p < 0.001]. For all stages of CKD, independent of diabetes status, minor LEA were performed with greater frequency than major LEA. In patients with DM, LEA rates significantly increased with CKD progression between stages 2-5 with a substantial jump between stages 4 and 5 [OR 2.6 (CI 2.49-2.74), p < 0.001]. However, CKD progression between stages 1 and 2 was not significantly associated with increased LEA rates (OR 1.1 (CI 0.92-1.21), p = 0.24) in patients with diabetes. Patients with comorbid diabetes have elevated risk for LEA at all stages of CKD compared to those without diabetes.

Moderate and Severe Chronic Kidney Disease Predict Greater 5-Year Mortality following Major Lower-Extremity Amputation

BACKGROUND

Severe chronic kidney disease (CKD) predicts greater mortality after major lower-extremity amputation (LEA), but it remains poorly understood whether patients with earlier stages of CKD share similar risk.

METHODS

We assessed long-term postoperative outcomes for patients with CKD in a retrospective chart review of 565 patients who underwent atraumatic major LEA at a large tertiary referral center from 2015 to 2021. We stratified patients by renal function and compared outcomes including survival.

RESULTS

Preoperative CKD diagnosis was related to many patient characteristics, co-occurred with many comorbidities, and was associated with less follow-up and survival. Kaplan-Meier and Cox Regression analyses showed significantly worse 5-year survival for major LEA patients with mild, moderate, or severe CKD compared to major LEA patients with no history of CKD at the time of amputation (P < 0.001). Severe CKD independently predicted worse mortality at 1-year (odds ratio [OR] 2.91; P = 0.003) and 5-years (OR 3.08; P < 0.001). Moderate CKD independently predicted worse 5-year mortality (OR 2.66; P = 0.029).

CONCLUSIONS

This study demonstrates that moderate and severe CKD predict greater long-term mortality following major LEA when controlling for numerous potential confounders. This finding raises questions about the underlying mechanism if causal and highlights an opportunity to improve outcomes with earlier recognition and optimization CKD preoperatively.

Chronic Kidney Disease Predicts Greater 5-Year Mortality Following Major Limb Amputation

Severe chronic kidney disease (CKD) predicts greater mortality after major lower extremity amputation (MLEA), but it remains poorly understood whether this finding extends to patients with earlier stages of CKD. We assessed outcomes for patients with CKD in a retrospective chart review of all patients who underwent MLEA at a large tertiary referral center from 2015 to 2021. We stratified 398 patients by glomerular filtration rate (GFR) and conducted Chi-Square and survival analysis. Preoperative CKD diagnosis was associated with many comorbidities, less 1-year follow-up, and greater 1- and 5-year mortality. Kaplan-Meier analysis showed worse 5-year survival for patients with any stage of CKD (62%) compared to patients without CKD (81%; P < .001). Greater 5-year mortality was independently predicted by moderate CKD (hazard ratio (HR) 2.37, P = .02) as well as severe CKD (HR 2.09, P = .005). These findings demonstrate the importance of identifying and treating CKD early preoperatively.

A Systematic Review and Meta-analysis of General versus Regional Anesthesia for Lower Extremity Amputation

OBJECTIVE

Postoperative morbidity in patients undergoing lower extremity amputation (LEA) has remained high. Studies investigating the influence of the anesthetic modality on the postoperative outcomes have yielded conflicting results. The aim of our study was to assess the effects of regional anesthesia vs general anesthesia on postoperative complications for patients undergoing LEA.

METHODS

We systematically searched PubMed, Embase, MEDLINE, Web of Science, and Google Scholar from 1990 to 2022 for studies investigating the effect of the anesthetic modality on the postoperative outcomes after LEA. Regional anesthesia (RA) included neuraxial anesthesia and peripheral nerve blocks. The outcomes included 30-day mortality, respiratory failure (unplanned postoperative intubation, failure to wean, mechanical ventilation >24 hours), surgical site infection, cardiac complications, urinary tract infection, renal failure, sepsis, venous thrombosis, pneumonia, and myocardial infarction.

RESULTS

Of the 25 studies identified, we included 10 retrospective observational studies with 81,736 patients, of whom 69,754 (85.3%) had received general anesthesia (GA) and 11,980 (14.7%) had received RA. In the GA group, 50,468 patients were men (63.8%), and in the RA group, 7813 patients were men (62.3%). The results of the meta-analyses revealed that GA was associated with a higher rate of respiratory failure (odds ratio, 1.38; 95% confidence interval, 1.06-1.80; P = .02) and sepsis (odds ratio, 1.21; 95% confidence interval, 1.11-1.33; P < .0001) compared with RA. No differences were found in postoperative 30-day mortality, surgical site infection, cardiac complications, urinary tract infection, renal failure, venous thrombosis, pneumonia, and myocardial infarction between the GA and RA groups.

CONCLUSIONS

The results of our meta-analysis have shown that GA could be associated with a higher rate of respiratory failure and sepsis compared with RA for LEA.

Unique closure of Gustilo IIIA fracture with a hard-to-heal lower extremity wound

Consistently achieving wound closure requires a broad understanding of wound physiology, anatomy and wound healing phases. The multifaceted principles of wound closure are comprised of: perfusion evaluation; diabetes control; nutritional optimisation; infection control; mechanical stress avoidance; oedema management; wound bed preparation; and community care. Optimisation of each element is crucial to timely and durable resolution of acute and hard-to-heal wounds. This objective is realisable only through an interdisciplinary approach to wound healing. The reconstructive ladder represents the graduation of complex wound management as applied by the specialty of plastic surgery. The approach to reconstruction typically begins with the least invasive option, which is considered reliable. However, there are instances when the most reliable option on the reconstructive ladder is not a viable option and creative solutions for wound closure are required. The following case report demonstrates a unique approach to lower extremity salvage in a subacute compound fracture surgical site infection using a limited reconstructive ladder.

Long-term Mortality After Nontraumatic Major Lower Extremity Amputation: A Systematic Review and Meta-analysis

Chronic wounds that lead to major lower extremity amputation have immense consequences on quality of life, and ultimately, mortality. However, mortality rates after lower extremity amputation for a chronic wound are broad within the literature and have escaped precise definition. This systematic review aims to quantify long-term mortality rates after major lower extremity amputation in the chronic wound population available in the existing literature. Ovid MEDLINE was searched for publications which provided mortality data after major, nontraumatic, primary lower extremity amputations. Lower extremity amputations were defined as below and above the knee amputation. Data from included studies was analyzed to obtain pooled 1-, 2-, 3-, 5- and 10-year mortality rates. Sixty-one studies satisfied inclusion criteria representing 36,037 patients who underwent nontraumatic major lower extremity amputation. Pooled mortality rates were 33.7%, 51.5%, 53%, 64.4%, and 80% at 1-, 2-, 3-, 5- and 10-year follow-up, respectively. Within the 8184 diabetic patients (types 1 and 2), 1- and 5-year mortality was 27.3% and 63.2%. Sources of mortality data were varied and included electronic medical records, national health and insurance registries, and government databases. Mortality after nontraumatic major lower extremity amputation is high, both in patients with diabetes as well as those without. Methods used to measure and report mortality are inconsistent, lack reliability, and may underestimate true mortality rates. These findings illustrate the need for a paradigm shift in wound management and improved outcomes reporting. A focus on amputation prevention and care within a multidisciplinary team is critical for recalcitrant ulcers.

Survival and factors predicting mortality after major and minor lower-extremity amputations among patients with diabetes: a population-based study using health information systems

INTRODUCTION

The aim of the study was to identify the sociodemographic and clinical factors associated with death after the first lower-extremity amputation (LEA), minor and major separately, using data from regional health administrative databases.

RESEARCH DESIGN AND METHODS

We carried out a population-based cohort study including patients with diabetes residing in the Lazio region and undergoing a primary amputation in the period 2012-2015. Each individual was followed up for at least 2 years. Kaplan-Meier analysis was used to evaluate long-term survival; Cox proportional regression models were applied to identify factors associated with all-cause mortality.

RESULTS

The cohort included 1053 patients, 72% were male, 63% aged ≥65 years, and 519 (49%) died by the end of follow-up. Mortality rates at 1 and 4 years were, respectively, 33% and 65% for major LEA and 18% and 45% for minor LEA. Significant risk factors for mortality were age ≥65, diabetes-related cardiovascular complications, and chronic renal disease for patients with minor LEA, and age ≥75 years, chronic renal disease and antidepressant drug consumption for subjects with major LEA.

CONCLUSIONS

The present study confirms the high mortality rates described in patients with diabetes after non-traumatic LEA. It shows differences between minor and major LEA in terms of mortality rates and related risk factors. The study highlights the role of depression as specific risk factor for death in patients with diabetes after major LEA and suggests including its definition and management in strategies to reduce the high mortality rate observed in this group of patients.

Risk factors and safe contrast volume thresholds for postcontrast acute kidney injury after peripheral vascular interventions

OBJECTIVE

Postcontrast acute kidney injury (PC-AKI) is a dreaded complication of peripheral vascular interventions (PVIs) that depends on the volume of contrast administered as well as a patient's baseline kidney function. However, there is currently no guidance on the volume of contrast that is considered safe especially for patients with advanced chronic kidney disease (CKD). This study aims to characterize the incidence, risk factors for, and outcomes after PC-AKI and define thresholds of safety for contrast volume.

METHODS

The Vascular Quality Initiative files for PVI (2010-2018) were reviewed. Patients on dialysis, with renal transplants, or who developed a bleeding complication were excluded. Only records with complete data on baseline creatinine, contrast volume, and PC-AKI (creatinine increase of ≥0.5 mg/dL, or new dialysis requirement) were included. The cumulative incidence of PC-AKI with contrast volume at each stage of CKD was derived. A safe threshold for contrast volume was defined as the volume at which the cumulative incidence of PC-AKI is 0.5% or less. Multivariable logistic regression was used to define risk factors for PC-AKI, and survival analysis was performed using Kaplan-Meier and multivariable Cox proportional hazards regression.

RESULTS

A total of 53,780 procedures were included. There were 16,062 patients (29%) with normal kidney function or CKD1, 21,769 (39%) with CKD2, 14,234 (25%) with CKD3, 1471 (3%) with CKD4, and 199 (<1%) with CKD5. The incidence of PC-AKI was 0.9% and increased with each stage of CKD (CKD1, 0.39%; CKD2, 0.45%; CKD3, 1.5%; CKD4, 4.3%; and CKD5, 7.5%). The safe thresholds for contrast volume for advanced CKD were 50, 20, and 9 mL for CKD3, CKD4, and CKD5, respectively. Regression analysis demonstrated that white race (odds ratio [OR], 0.67; 95% confidence interval [CI], 0.54-0.82) and elective surgery (OR, 0.77; 95% CI, 0.62-0.95) were associated with decreased risk of PC-AKI, whereas inpatient status (OR, 14.5; 95% CI, 9.97-21.2), diabetes (OR, 1.27; 95% CI, 1.02-1.58), advanced CKD (CKD3: OR, 3.65; 95% CI, 2.68-4.98; CKD4: OR, 6.98; 95% CI, 4.72-10.3; CKD5: OR, 8.94; 95% CI, 4.53-17.6), critical limb ischemia (OR, 1.51; 95% CI, 1.14-2.00), acute limb ischemia (OR, 2.47; 95% CI, 1.70-3.59), and contrast-to-eGFR ratio (CGR) (2 ≤ CGR < 3: OR, 1.33; 95% CI, 1.02-1.74; 3 ≤ CGR < 4: OR, 1.90; 95% CI, 1.32-2.75; CGR ≥ 4: OR, 1.79; 95% CI, 1.18-2.70) were significantly associated with increased risk for PC-AKI. Patients who developed PC-AKI had worse in-hospital (16.1% vs 0.45%; P < .01) mortality and long-term survival (log-rank P < .01) compared with those without PC-AKI.

CONCLUSIONS

PVI are associated with low risk of PC-AKI that significantly increases when patients with advanced CKD undergo high acuity cases. Given the strong association with short-term and long-term mortality, risk of PC-AKI should be minimized by using safe thresholds of contrast volume.

Time Trends in the Incidence of Long-Term Mortality in T2DM Patients Who Have Undergone a Lower Extremity Amputation. Results of a Descriptive and Retrospective Cohort Study

(1) Background: The aims of this study were to examine the incidence of lower extremity amputations (LEAs) among patients with type 2 diabetes mellitus (T2DM) and to compare the mortality risk of diabetic individuals who underwent LEA with age and sex-matched diabetic individuals without LEA. (2) Methods: We performed a descriptive observational study to assess the trend in the incidence of LEA and a retrospective cohort study to evaluate whether undergoing LEA is a risk factor for long-term mortality among T2DM patients. Data were obtained from the Hospital Discharge Database for the Autonomous Community of Madrid, Spain (2006–2015). (3) Results: The incidence rates of major below-knee and above-knee amputations decreased significantly from 24.9 to 17.1 and from 63.9 to 48.2 per 100000 T2DM individuals from 2006 to 2015, respectively. However, the incidence of minor LEAs increased over time. Mortality was significantly higher among T2DM patients who underwent LEA compared with those who did not undergo this procedure (HR 1.75; 95% CI 1.65–1.87). Male sex, older age, and comorbidity were independently associated with higher mortality after LEA. (4) Conclusions: Undergoing a LEA is a significant risk factor for long term mortality among T2DM patients, and those who underwent a major above-knee LEAs have the highest risk.

General outcomes and risk factors for minor and major amputations in Brazil

Objectives Major and minor amputations are associated with significant rates of mortality. However, little is known about the impact of unplanned redo-amputation during the same hospitalization on outcomes. The objectives of this study were to identify the risk factors associated with in-hospital mortality after both major and minor amputations as well as the results of unplanned redo-amputation on outcome. Methods Retrospective study of 342 consecutive patients who were treated with lower extremity amputation in Brazil between January 2013 and October 2014. Results The in-hospital mortality rate was higher in major compared to minor amputation (25.6% vs. 4.1%; p < 0.0001). Whereas chronic kidney disease, chronic obstructive pulmonary disease, and planned staged amputation predicted in-hospital mortality after major amputation, age, and congestive heart failure predicted mortality after minor amputation. The white blood cell count predicted in-hospital mortality following both major and minor amputation. However, postoperative infection predicted in-hospital mortality only following major amputation. Conclusions In-hospital mortality was high after major amputations. Unplanned redo-amputation was not a predictor of in-hospital mortality after major or minor amputation. Planned staged amputation was associated with reduced survival after major but not minor amputation. Postoperative infection predicted mortality after major amputation. Systemic diseases and postoperative white blood cell were associated with in-hospital mortality. This study suggests a possible link between a pro-inflammatory state and increased in-hospital mortality following amputation.

Predictors of in-hospital mortality following major lower extremity amputations in type 2 diabetic patients using artificial neural networks

BACKGROUND

Outcome prediction is important in the clinical decision-making process. Artificial neural networks (ANN) have been used to predict the risk of post-operative events, including survival, and are increasingly being used in complex medical decision making. We aimed to use ANN analysis to estimate predictive factors of in-hospital mortality (IHM) in patients with type 2 diabetes (T2DM) after major lower extremity amputation (LEA) in Spain.

METHODS

We design a retrospective, observational study using ANN models. We used the Spanish National Hospital Discharge Database to select all hospital admissions of major LEA procedure in T2DM patients.

MAIN OUTCOME MEASURES

Predictors of IHM using 4 ANN models: i) with all discharge diagnosis included in the database; ii) with all discharge diagnosis included in the database, excluding infectious diseases; iii) comorbidities included in the Charlson Comorbidities Index; iv) comorbidities included in the Elixhauser Comorbidity Index.

RESULTS

From 2003 to 2013, 40,857 major LEAs in patients with T2DM were identified with a 10.0% IHM. We found that Elixhauser Comorbidity Index model performed better in terms of sensitivity, specificity and precision than Charlson Comorbidity Index model (0.7634 vs 0.7444; 0.9602 vs 0.9121; 0.9511 vs 0.888, respectively). The area under the ROC curve for Elixhauser comorbidity model was 91.7% (95% CI 90.3-93.0) and for Charlson comorbidity model was 88.9% (95% CI; 87.590.2) p = 0.043. Models including all discharge diagnosis with and without infectious diseases showed worse results. In the Elixhauser Comorbidity Index model the most sensitive parameter was age (variable sensitive ratio [VSR] 1.451) followed by female sex (VSR 1.433), congestive heart failure (VSR 1.341), renal failure (VSR 1.274) and chronic pulmonary disease (VSR 1.266).

CONCLUSIONS

Elixhauser Comorbidity Index is a superior comorbidity risk-adjustment model for major LEA survival prediction in patients with T2DM than Charlson Comorbidity Index model using ANN models. Female sex, congestive heart failure, and renal failure are strong predictors of mortality in these patients.

Rehabilitation Outcomes After Inpatient Rehabilitation for Lower Extremity Amputations in Patients With Diabetes

OBJECTIVE

To identify factors associated with functional gain, discharge destination, and long-term survival after inpatient rehabilitation in patients with lower extremity amputation and diabetes.

DESIGN

Retrospective medical records review.

SETTING

All community hospitals.

PARTICIPANTS

Patients with diabetes (N=256) admitted for inpatient rehabilitation after lower extremity amputation.

INTERVENTIONS

Not applicable.

MAIN OUTCOMES MEASURES

Absolute functional gain (AFG) using the Shah-modified Barthel Index, discharge destination, and long-term survival for each patient.

RESULTS

Length of stay (B=.15; 95% confidence interval [CI], .08-.21; P<.001) and admission functional status (B=-.09; 95% CI, -.18 to -.01; P=.032) were significantly associated with AFG. Availability of caregiver (foreign domestic worker: odds ratio [OR], 16.39; 95% CI, 4.65-57.78; P<.001; child: OR, 3.82; 95% CI, 1.31-11.12; P=.014; spouse: OR, 2.82; 95% CI, 1.07-7.46; P=.037 vs none), Charlson Comorbidity Index of 1 (OR, 4.32; 95% CI, 1.34-13.93; P=.014 vs ≥4), and younger age (OR, .96; 95% CI, .93-.99; P=.02) were significantly associated with being discharged home. Admission functional status (hazard ratio [HR], .98; 95% CI, .97-.99; P<.001), AFG (HR, .99; 95% CI, 0.97-1.00; P=.058), Charlson Comorbidity Index (1 vs ≥4: HR, .42; 95% CI, .24-.77; P=.004), ischemic heart disease (HR, 2.25; 95% CI, 1.27-4.00; P=.006), discharge destination (other vs home: HR, 1.82; 95% CI, 1.02-3.23; P=.041), age (HR, 1.02; 95% CI, 1.00-1.03; P=.082), and ethnicity (Malay vs Chinese: HR, .37; 95% CI, .16-.87; P=.022) predicted survival postamputation.

CONCLUSIONS

Admission functional status predicted both functional gain during rehabilitation and survival in these patients. We also found ethnic differences in outcomes, with Malays having better survival after amputation. Lastly, there appears to be greater reliance on foreign domestic workers as caregivers, with patients with foreign domestic workers as their primary caregiver having the highest odds of being discharged home.