Preoperative Nil Per Os Duration Predicts Mortality and Ambulation Following Below-Knee Amputation.

BACKGROUND: Routine use of nil per os (NPO) prior to procedures has been associated with dehydration and malnutrition leading to patient discomfort. We aim to examine how duration of NPO status affects postoperative outcomes in patients undergoing elective below-knee amputation (BKA). METHODS: We performed a retrospective chart review of 92 patients who underwent elective BKA between 2014-2022 for noninfectious indications. We performed statistical analysis using Chi-square tests, t-tests, and linear/logistic regression with odds ratio using P < .05 as our significance level. RESULTS: The mean age was 48.0 ± 16.7 years, and there were 64 (70%) male patients and 41 (45%) Black patients. Mean NPO duration was 12.9 ± 4.7 hours. Patients with longer NPO duration were associated with increased rates of postoperative stroke (P = .03). Patients with shorter NPO duration had significantly lower mean BUN on postoperative day (POD) 1 (14.5, P < .001) and POD 3 (14.1, P < .001) compared to preoperative mean BUN (16.8), however this normalized by POD 7 (19.2, P = .26). There were no changes in postoperative renal function based on baseline kidney disease status or associated with longer NPO duration. Shorter NPO duration was a predictor of increased likelihood of 1-year follow-up (OR: 2.9 [1.24-6.79], P = .01), independent ambulation (OR: 2.7 [1.03-7.34], P = .04), and decreased mortality (OR: .11 [.013-.91], P = .04). CONCLUSION: While NPO duration does not appear to result in postoperative renal dysfunction, prolonged NPO duration predicts worse rates of follow-up, ambulation, and survival and is associated with increased stroke rates.

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.

Delayed Closure of Guillotine Lower Extremity Amputation in Obese Patients is Associated with Increased Mortality.

BACKGROUND: Staged surgery with open guillotine amputation (OGA) prior to a definitive major lower extremity amputation (LEA) has been shown to be effective for sepsis control and improving wound healing. Studies have evaluated postoperative complications including infection, return to the operating room for re-amputation, and amputation failure following OGA. However, the role of timing to close OGA for predictive outcomes remains poorly understood. We aim to assess outcomes of major LEA related to the time of OGA closure. METHODS: Data from patients who underwent major LEA from 2015 to 2021 were collected retrospectively. The study included all patients undergoing below-knee, through-knee, or above-knee amputations. Next, patients who had OGA prior to a definitive amputation were selected. Patients who died before amputation closure were excluded. Postamputation outcomes such as surgical site infection, postoperative sepsis, postoperative ambulation, hospital length of stay, and 30-day, 1-year, and 5-year mortality were reviewed. The study cohort was stratified by demographics and comorbidities. Receiver operating characteristic curve analysis was performed to determine the time of closure (TOC) cutoff value. Univariate and multivariate analysis was performed to assess outcomes. Statistical significance was set at P < 0.05. RESULTS: Of 688 patients who underwent major LEA, 322 underwent staged amputation with OGA before the formalization procedure and were included. The TOC ranged from 1-47 days with a median of 4 days (interquartile range from 3 to 7). The optimal TOC point of 8 days (ranging from 2-42 days) in obese patients (199/322) for predicting mortality showed the largest area under the curve (0.709) with 64.71% sensitivity and 78.3% specificity. Patients who are obese and grouped in TOC less than 8 days had no 30-day mortality, significantly lower 1-year mortality, better survival, and a lower rate of deep venous thrombosis complication. There was no significant difference in length of stay, postoperative surgical site infection, sepsis, and ambulation between the 2 subgroups of obese patients. Multivariable analysis showed that gender, chronic kidney disease, and postoperative ambulation independently predict overall mortality in obese patients. CONCLUSIONS: TOC cutoff in obese patients showed statistically significant results in predicting mortality. Our findings indicated better survival in obese patients with a lower TOC (less than 8 days). This emphasizes the importance of earlier closure of OGA in obese patients.

Modified Frailty Index Helps Predict Mortality and Ambulation Differences Between Genders and Racial Differences Following Major Lower Extremity Amputation.

BACKGROUND: Major lower extremity amputation (LEA) is associated with significant morbidity and mortality. The modified frailty index (mFI-5) has been used to predict outcomes including ambulation and mortality after LEA. It remains unknown for which patient demographics the mFI-5 is a reliable predictor. METHODS: This was a retrospective review of all patients who underwent a first-time major LEA at our institution from 2015 to 2022. Patients were stratified into 2 risk groups based on their mFI-5 score: non-frail (mFI<3) and frail (mFI≥3) and assessed on outcomes. RESULTS: Our sample consisted of 687 patients of whom 134 (19.6%) were considered frail and 551 (80.4%) were considered non-frail. A higher mFI-5 is associated with decreased ambulation rates (OR: 0.565, P = .004), increased hospital readmission (OR: 1.657, P = .021), and increased mortality (OR: 2.101, P = .001) following major LEA. In African American patients, frail and non-frail patients differed on readmission at 90 days (P = .008), mortality at 1 year (P = .001), ambulatory status (P < .001), and prosthesis use (P = .023). In male patients, frail and non-frail patients differed on readmission at 90 days (P = .019), death at 1 year (P = .001), and ambulatory status (P = .002). In Caucasian patients and female patients, frail and non-frail patients did not differ significantly on outcomes. DISCUSSION: The mFI-5 is a valuable predictor of outcomes following major LEA, specifically in males and African American patients. Moreover, surgeons should consider using frailty status to risk stratify patients and inform treatment plans.

Opioid Use Disorder in Patients Undergoing Major Lower Extremity Amputation: Prevalence and Outcomes.

INTRODUCTION: Patients with a history of Opioid Use Disorder (OUD) have higher postoperative complication rates and mortality in many settings. Yet, it remains poorly understood how the opioid epidemic has affected patients undergoing major lower extremity amputation (LEA) and whether outcomes differ by OUD status. METHODS: We conducted a retrospective chart review of all 689 patients who underwent major LEA at a large tertiary referral center from 2015 to 2021. This study assessed patient characteristics and long-term postoperative outcomes for patients with preoperative OUD. RESULTS: 133 (19.3%) patients had a lifetime history of preoperative OUD. Preoperative OUD was associated with key characteristics, comorbidities, and outcome measures. OUD was significantly associated with younger age (P < .001), black race (P = .026), single relationship status (P < .001), BMI <30 (P = .024), no primary care provider (P = .004), and Medicaid insurance (P < .001). Comorbidities significantly associated with OUD include current smoking (P < .001), Human Immunodeficiency Virus (HIV; P = .003), and history of osteomyelitis (P < .001). Preoperative OUD independently predicted lower rates of 30-60-day readmission (odds ratio [OR] .54, P = .018) and 1-12-month reamputation (OR .41, P = .006). There was no significant difference in long-term mortality and follow-up. CONCLUSION: This study demonstrates the prevalence of OUD in patients undergoing major LEA and reports associations and long-term outcomes. Our findings highlight the importance of recognizing OUD and raise questions about the mechanisms underlying its relation to rates of postoperative readmission and reamputation.

Comparison of Pre-existing Mood Disorders and Chronic Kidney Disease as Predictors of Ambulatory Status After Major Limb Amputation.

Objective We aim to compare the effects of pre-existing mood disorders and chronic kidney disease (CKD) on ambulation outcomes for patients who have undergone major lower extremity amputation (MLEA) while also stratifying by the presence of social factors. Methods  We performed a retrospective chart review of 700 patients admitted from 2014 to 2022 who underwent MLEA. We performed Chi-square tests and binomial logistic regression with p < 0.05 as our significance level. Results Mood disorder patients have higher rates of independent ambulation if they have familial support (p = 0.022), a listed primary care provider (PCP; p = 0.013), a six-month follow-up (p < 0.001), or a one-year follow-up (p < 0.001). Patients with a history of mood disorder have significantly decreased odds of prosthesis usage (OR: 0.58, 95% CI: 0.40-0.86) but have higher rates of prosthesis usage if they have familial support (p = 0.002), a PCP listed (p = 0.005), a six-month follow-up (p < 0.001), or a one-year follow-up (p < 0.001). CKD patients have significantly decreased odds of eventual independent ambulation (OR: 0.69, 95% CI: 0.49-0.97) but have significantly increased rates of independent ambulation if they have familial support (p =0.041) and six-month (p < 0.001) or one-year follow-up (p < 0.001). CKD patients only have significant changes in prosthesis usage with a six-month (p < 0.001) or one-year follow-up (p < 0.001). Conclusions Pre-existing CKD and mood disorders are associated with decreased odds of independent ambulation and prosthesis usage, respectively. Social factors such as family support, a listed PCP, and timely follow-up are associated with markedly improved ambulatory outcomes for MLEA patients with mood disorders and CKD, with significantly improved prosthesis usage outcomes in only the mood disorder population.

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.