Major Lower Extremity Amputation Research Articles

The phenomenon of drug-coating embolism during lower extremity endovascular interventions with paclitaxel-coated balloon.

There is a risk of distal embolization lower extremity endovascular interventions. Possibly a drug-coating embolism caused by coating detachment from intravascular devices. This review focuses on providing updated information on distal embolism in endovascular revascularization of lower extremity arteries, including the use of drug-coated balloons. Drug-coating embolism is a special case of distal embolization during recanalization of the arteries of the lower extremities. Preclinical studies have demonstrated embolization of drug-coated balloons during angioplasty of lower extremity arteries. However, the clinical role of drug-coating embolism is not completely clear. A 2020 meta-analysis found an increased risk of major lower extremity amputation after drug-coated balloon angioplasty in patients with critical limb ischemia. But long-term research is emerging to support the safety of using these devices. Perhaps a more thorough assessment of the quality of life and the degree of compensation of lower limb ischemia with an intraoperative assessment of the frequency of peripheral embolizations using ultrasound emboli detection, as well as microcirculation with transcutaneous oximetry and laser Doppler flowmetry of the operated lower limb will allow a more detailed study of the phenomenon of drug-coating embolism and its impact on long-term clinical outcomes. According to the results of preclinical studies, the use of paclitaxel-coated balloons leads to an increase in the concentration of paclitaxel in distal skeletal muscles. However, paclitaxel concentration in skeletal muscle was significantly higher in first-generation DCBs. The non-target effects of drug-coating balloon are not fully understood and require further study. Understanding the phenomenon of drug-coating embolism can help physicians to better assess the patient risk and to minimize complications.

Rapid Access From Primary Care to a Multidisciplinary Clinic at Tertiary Care Improves Clinical Outcomes for Patients With Diabetic Foot Ulcers: Results From Diabetic Foot in Primary and Tertiary (DEFINITE) Care's Lower Extremity Amputation Prevention Program (LEAPP) Clinic.

Diabetic Foot in Primary and Tertiary (DEFINITE) Care is an inter-institutional, multidisciplinary team (MDT) program for patients with diabetic foot ulcers (DFU) within a healthcare cluster in Singapore. This is one of our subgroup analyses within DEFINITE Care, assessing clinical outcomes of lower extremity amputation prevention program (LEAPP), a multidisciplinary diabetic foot clinic, and non-LEAPP patients within the program. From June 2020 to June 2022, 2798 patients within the DEFINITE cohort completed a minimum of 12-month follow up. Of these patients, 20.6% were managed by LEAPP, whereas 79.4% were non-LEAPP patients. Patients in the LEAPP cohort were older with co-existing metabolic conditions and complications of diabetes. Using non-LEAPP cohort as the reference group and after adjusting for age, gender, ethnicity, comorbidities, and medications, there was a significantly lower risk of death (odds ratio [OR] 0.60, P = .001) and composite major lower extremity amputation (LEA) or death (OR 0.66, P = .002) among LEAPP patients at 1 year with longer mean days from enrollment to minor LEA, major LEA, and death. The adjusted 1-year healthcare utilization outcomes for LEAPP patients demonstrated an increase in inpatient admissions, primary care polyclinic visits, hospital specialist outpatient clinic (SOC) visits and elective day surgery procedures. Despite the increased in inpatients admissions, cumulative hospital length of stay in LEAPP patients were lower. This subgroup analysis has demonstrated that the MDT approach to caring for patients with DFU in tertiary centers not only improves mortality by 40%, but also delayed the incidence of minor LEA, major LEA, and death.

Association Between Diagnosis-to-Limb Revascularization Time and Clinical Outcomes in Outpatients With Chronic Limb-Threatening Ischemia: Insights From the CLIPPER Cohort.

The extent and consequences of ischemia in patients with chronic limb-threatening ischemia (CLTI) may change rapidly, and delays from diagnosis to revascularization may worsen outcomes. We sought to describe the association between time from diagnosis to endovascular lower extremity revascularization (diagnosis-to-limb revascularization [D2L] time) and clinical outcomes in outpatients with CLTI. In the CLIPPER cohort, comprising patients between 66 and 86 years old diagnosed with CLTI betweeen 2010 and 2019, we used Medicare claims data to identify patients who underwent outpatient endovascular revascularization within 180 days of diagnosis. We described the risk-adjusted association between D2L time and clinical outcomes. Among 1 130 065 patients aged between 66 and 86 years with CLTI, 99 221 (8.8%) underwent outpatient endovascular lower extremity revascularization within 180 days of their CLTI diagnosis. Among patients with D2L time <30 days, there was no association between D2L time and all-cause death or major lower extremity amputation. However, among patients with D2L time >30 days, each additional 10-day increase in D2L time was associated with a 2.5% greater risk of major amputation (hazard ratio, 1.025 [95% CI, 1.014-1.036]). There was no association between D2L time and all-cause death. A delay of >30 days from CLTI diagnosis to lower extremity endovascular revascularization was associated with an increased risk of major lower extremity amputation among patients undergoing outpatient endovascular revascularization. Improving systems of care to reduce D2L time could reduce amputations.

Prosthetic Fitting and Mortality after Major Lower Extremity Amputation

IntroductionStudies suggest that ambulation after major lower extremity amputation (LEA) is low and mortality after LEA is high. Successful prosthetic fitting after LEA has a significant quality of life benefit, however, it is unclear if there are benefits in post-LEA mortality. Our objective was to examine a contemporary cohort of patients who underwent LEA and determine if there is an association between fitting for a prosthetic and mortality. MethodsWe reviewed all patients who underwent LEA between 2015 and 2022 at two academic healthcare systems in a large metropolitan city. The exposure of interest was prosthetic fitting after LEA. The primary outcomes were mortality within 1- and 3-years of follow-up. Ambulation after LEA was defined as being ambulatory with or without an assistive device. Patients with prior LEA were excluded. Extended Cox models with time-dependent exposure were used to evaluate the association between prosthetic fitting and mortality at 1- and 3-years of follow up. ResultsAmong 702 patients who underwent LEA, the mean (SD) age was 64.3 (12.6) years and 329 (46.6%) were fitted for prosthetic. The study population was mostly male (n=488, 69.5%), predominantly Non-Hispanic Black (n=410, 58.4%), and nearly one-fifth were non-ambulatory prior to LEA (n=139, 19.8%). Of note, 14.3% of all subjects who were non-ambulatory at some point after LEA, and 28.5% of patients not ambulatory preoperatively were eventually ambulatory after LEA. The rate of death among those fitted for a prosthetic was 12.0/100 person-years at 1 year and 5.8/100 person-years at 3 years of follow up and among those not fitted for a prosthetic, the rate of death was 55.7/100 person-years and 50.7/100 person-years at 1- and 3-years of follow up, respectively. After adjusting for several sociodemographic data points, comorbidities, pre- or post-COVID pandemic timeframe, and procedural factors, prosthetic fitting is associated with decreased likelihood of mortality within 1 year of follow-up (adjusted hazard ratio [aHR] 0.24; 95% CI, 0.14 - 0.40) as well as within 3 years (aHR 0.40; 95% CI, 0.29 - 0.55). ConclusionsProsthetic fitting is associated with improved survival and preoperative functional status does not always predict postoperative functional status. Characterizing patient, surgical, and rehabilitation factors associated with receipt of prosthetic after LEA may improve long-term survival in these patients. Process measures employed by the VA, such as prosthetic department evaluation of all amputees, may represent a ‘best practice’.

Five-Year Trends of Vascular Disease-Related Amputations in Romania: A Retrospective Database Study.

Background/Objectives: Lower extremity amputations (LEAs) are a burdensome complication of peripheral artery disease (PAD) and/or arterial embolism and thrombosis (AET). We assessed the trends in PAD- and/or AET-related LEAs in Romania. Methods: This retrospective study (2015-2019) analyzed data on minor and major LEAs in hospitalized patients recorded in the National School for Public Health, Management, and Health Education database. The absolute numbers and incidences of LEAs were analyzed by diagnosis type, year, age, sex, and amputation level. Results: Of 38,590 vascular disease-related amputations recorded nationwide, 36,162 were in PAD and 2428 in AET patients. The average LEA incidence in the general population was 34.73 (minimum: 31.96 in 2015; maximum: 36.57 in 2019). The average incidence of major amputations, amputations above the knee, hip amputations, amputations below the knee, and minor amputations was 16.21 (15.62 in 2015; 16.84 in 2018), 13.76 (13.33 in 2015; 14.28 in 2018), 0.29 (0.22 in 2017; 0.35 in 2019), 2.15 (2.00 in 2015; 2.28 in 2019), and 18.52 (16.34 in 2015; 20.12 in 2019), respectively. Yearly PAD- and/or AET-related amputations were significantly higher in men versus women. The overall number of LEAs increased with age, particularly in patients ≥ 70 years. The increase in the total number of amputations was mainly due to a constant rise in minor amputations for both groups, regardless of gender. Conclusions: PAD- and/or AET-related LEAs in Romania increased from 2015 to 2019, with men having a greater incidence than women. Raising awareness and effective management strategies are needed to prevent LEAs.

Postural control imbalance in individuals with a minor lower extremity amputation: a scoping review protocol.

Introduction Lower extremity amputations (LEA) impact the quality of life and physical abilities and increase the risk of developing secondary health complications. Current literature predominantly focuses on major LEA, leaving a gap in understanding biomechanics related to balance and postural control in minor LEA. The shifts towards increased rates of minor LEA, due to improved quality of care and patient management, highlights the need for a focused exploration of postural control deficits in this population. The scoping review will address this gap in the literature. Objectives The purpose of the review is to synthesize current research on postural control deficits following a minor foot amputation, focusing on any resections through or distal to the ankle joint, and to evaluate interventions aimed at improving balance in affected individuals. Inclusion criteria The review will encompass individuals of all ages who underwent a minor foot amputation, including various levels and etiologies. It will focus on quantitative data related to standing posture, ability to perform self-balanced activities of daily living, and external aids or treatments to improve postural control. The outcomes will include modifications in the sensation of balance, fall predictors, and biomechanical changes in postural control. Methods A preliminary search of MEDLINE (PubMed) was conducted to develop a full search strategy aimed at compiling all existing scientific articles on postural control and balance in individuals with a minor LEA. A comprehensive search will be performed across multiple databases and grey literature. Two reviewers will independently extract the data. The Mixed Methods Appraisal Tool will be used to assess risk and quality. Discussion By emphasizing the understudied aspects of postural control imbalances induced by minor LEA, the review will highlight potential areas for therapeutic intervention and contribute to a better understanding of rehabilitation for those affected.

Transitioning from hospital to home after a major lower extremity amputation: Interview study on patients' and relatives’ perspectives

IntroductionPatients often feel unprepared and concerned about their new life after a major lower extremity amputation (LEA). Therefore, we implemented an integrated care program, Safe Journey, to optimize the quality and continuity of care for patients with LEA due to vascular disease when transitioning from hospital to home. This study aims to illuminate and explore the experiences of patients with LEA and their relatives with the transition from hospital to home after implementing Safe Journey. Material and methodsThis qualitative, exploratory study individually interviewed six patients with a major LEA and four relatives and jointly interviewed eight patients with their relatives. ResultsThe participants’ experiences transitioning from hospital to home were centered around two major themes: (1) Going home: mixed emotions and confusion, and (2) bridging the gap. The main themes encompassed six subthemes: (1) simultaneously expectant and worried, (2) a lack of knowledge creating uncertainty, (3) an unexpressed but pending need for psychosocial support, (4) reassurance but safety comes at a price, (5) navigating the system, and (6) lack of involvement. ConclusionTransitioning from hospital to home after a major LEA creates mixed emotions. Knowledge, feeling involved, and being prepared and cared for were highlighted as important during the transition. The Safe Journey program made patients and relatives feel physically reassured and safe, but all the home visits strained the families. The program's benefits are consistent with existing knowledge on patients with complex needs benefitting from integrated care models. However, a more individualized and person-centered approach is needed.

Fatigue, fear of being mobilized and residual limb pain limit independent basic mobility and physiotherapy for patients early after major dysvascular lower extremity amputation: A prospective cohort study.

Early mobilization of patients with a major lower extremity amputation (LEA) is often a challenge because of lack of compliance. Therefore, we investigated factors limiting independent mobility and physiotherapy on the first day with physiotherapy (PTDay1) and the following 2 days after LEA. A total of 60 consecutive patients, mean age 73.7 years (SD 12.1 years), undergoing LEA were included over a period of 7 months. The Basic Amputee Mobility Score was used to assess basic mobility. Predefined limitations for not achieving independent mobility or not completing physiotherapy were residual limb pain, pain elsewhere, fear of being mobilized, fatigue, nausea/vomiting, acute cognitive dysfunction or "other" factors reported on PTDay1 and the following 2 days after LEA. Fatigue and fear of being mobilized were the most frequent limitations for not achieving independent mobility on PTDay1 and the following 2 days after LEA. Patients (n = 55) who were not independent in the Basic Amputee Mobility Score activity transferring from bed to chair on PTDay1 were limited by fatigue (44%) and fear of being mobilized (33%). A total of 21 patients did not complete planned physiotherapy on PTDay1, and were limited by fatigue (38%), residual limb pain (24%) and "other" factors (24%). Fatigue and fear of being mobilized were the most frequent factors that limited independent mobility early after LEA. Fatigue, residual limb pain and "other" factors limited completion of physiotherapy. Geriatr Gerontol Int 2024; 24: 470-476.

Factors Associated with Urgent Amputation Status and Its Impact on Mortality

ObjectivesThirty-day mortality is higher after urgent major lower extremity amputations compared to elective lower extremity amputations. This study aims to identify factors associated with urgent amputations and to examine their impact on perioperative outcomes and long-term mortality. MethodsPatients undergoing major lower limb amputation from 2013-2020 in the Vascular Quality Initiative (VQI) were included. Urgent amputation was defined as occurring within 72 hours of admission. Associations with sociodemographic characteristics, comorbidities, and outcomes including postoperative complication, inpatient death, and long-term survival were compared using univariable tests and multivariable logistic regression. Long-term survival between groups was compared using Kaplan-Meier analysis. ResultsOf the 12,874 patients included, 4,850 (37.7%) had urgent and 8,024 (62.3%) had elective amputations. Nonwhite patients required urgent amputation more often than white patients (39.8% vs 37.9%, P=0.03). A higher proportion of Medicaid and self-pay patients presented urgently (Medicaid:13.0% vs 11.0%; self-pay: 3.4% vs 2.5%, P< 0.001). Patients requiring urgent amputation were less often taking aspirin (55.6% vs 60.1%, P<0.001) or statin (62.2% vs 67.2%, P<0.001), had fewer prior revascularization procedures (41.0% vs 48.8%, P<0.001), and were of higher ASA class 4-5 (50.9% vs 40.1%, P<0.001). Urgent amputations were more commonly for uncontrolled infection (48.1% vs 29.4%, P< 0.001) or acute limb ischemia (14.3% vs 6.2%, P<0.001). Post-operative complications were higher after urgent amputations (34.7% vs 16.6%, P<0.001), including need for return to operating room (23.8% vs 8.4%, P< 0.001) and need for higher revision (15.2% vs 4.5%, P<0.001). Inpatient mortality was higher after urgent amputation (8.9% vs 5.4%, P<0.001). Multivariable analysis revealed non-white race, self-pay, homelessness, current smoking, ASA class 4-5, and amputations for uncontrolled infection or acute limb ischemia were associated with urgent status, whereas living in a nursing home or prior revascularization were protective. Further, urgent amputation was associated with an increased odds of postoperative complication or death (OR 1.86 [1.69-2.04], P<0.001) as well as long-term mortality (OR: 1.24 [1.13-1.35], P<0.001). Kaplan-Meier analysis corroborated that elective status was associated with improvement of long-term survival. ConclusionsPatients requiring urgent amputations are more often nonwhite, uninsured, and less frequently had prior revascularization procedures, revealing disparities in access to care. Urgency was associated with a higher post-operative complication rate, as well as increased long-term mortality. Efforts should be directed towards reducing these disparities to improve outcomes following amputation.

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

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. 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. 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). 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.

Initial handgrip strength as a predictive factor for amputation risk in diabetic foot patients

BackgroundWe aimed to analyze the prognostic significance of handgrip strength as predictor of lower extremity amputation at 1 year follow up in patients with type 2 diabetes. MethodsWe evaluated 526 patients with type 2 diabetes between August 2020, and, June 2022. We collected from the electronic medical records demographic variables, laboratory data and history of amputation. The handgrip strength was assessed using a handheld Smedley digital dynamometer following the NHANES Muscle Strenght/Grip Test Procedure. Low handgrip strength was defined for women as less than 16 kg and for men less than 27 kg. Outcome variable was major or minor lower extremity amputation. ResultsA total of 205 patients with complete data entered the study. Patients mean age was 59 years old, 37% were women and the mean diabetes disease duration was 14 years. Seventy-seven (37%) patients suffered from lower extremity mputations (26 major and 51 minor amputations). After controlling for age, gender, presence of peripheral artery disease, body mass index and white cell counts as confounder variables, patients with low handgrip had an increased risk for amputations (Odds Ratio 2.17; 95% confidence Interval: 1.09–4.32; <0.001). ConclusionLow handgrip stregth is an independent prognostic marker for lower limb amputation at one year in patients with diabetes.

Impact of a Quality Improvement Initiative on Medical Management of Veterans With Peripheral Artery Disease

Guideline-directed medical therapy (GDMT) for peripheral artery disease (PAD) remains severely underused. Prevention of Amputation in Veterans Everywhere (PAVE) is a screening program designed to prevent or delay major lower extremity amputation. This study aimed to determine whether diagnosis of PAD through the PAVE program improves the prescription of GDMT in veterans with asymptomatic PAD. Patients enrolled into the PAVE program from our institution from 2020 to 2021 were included. Patients with an abnormal ankle-brachial index (ABI), defined as ABI <0.9 or >1.2, were selected for further analysis. Primary outcome was adherence to GDMT, following class I and class IIa recommendations. Secondary outcomes included changes in low-density lipoprotein (LDL), blood pressure, and hemoglobin A1c (HbA1c). A total of 6,313 patients were enrolled into the PAVE program between 2020 and 2021. Of these, 211 had abnormal ABI and were included in our analysis. With enrollment into PAVE, there was significant increase in the prescription of aspirin (74.4% vs 64.9%, p = 0.044) and statins (91.5% vs 82%, p = 0.006). The overall adherence to GDMT significantly increased (56.9% vs 38.9%, p <0.001). The number of patients needed to enroll in PAVE to improve GDMT adherence is 5.6 (95% confidence interval 3.6 to 12.3). Patients enrolled into PAVE program saw significant decreases in HbA1c, with mean decrease of 0.3 (p = 0.012) and a decrease in LDL, with a mean decrease of 6.2 (p = 0.01). In conclusion, enrollment into an amputation prevention program secondarily increased adherence to GDMT, driven by increases in the prescription of statins and aspirin, with resulting decreases in HbA1c and LDL.

Midfoot Amputations as Adjuncts to Limb Preservation

Midfoot amputations are viable options for limb preservation in cases of forefoot infection, diabetic ulcers, critical limb ischemia, trauma, or malignancy to avoid major lower-extremity amputation. Each level of midfoot amputation has limitations to consider including wound healing problems, soft-tissue contracture, or need for revisional amputations. However, some of these facets can be addressed perioperatively. Each midfoot amputation has benefits as viable options for limb and functional preservation and to avoid major limb amputation. There currently is no set guideline for level of midfoot amputation in patients with critical limb ischemia. Levels of amputation are determined by multiple factors including but not limited to degree of tissue loss, vascular status, the ability to preserve function, surgeon experience, and pertinent patient factors. This approach to limb salvage is best performed from a multi-disciplinary perspective.

The continued financial effect of COVID: Increasing costs for non-elective major lower extremity amputations

BackgroundThe COVID-19 pandemic necessitated changes in processes of care, which significantly impacted surgical care. This study evaluated the impact of these changes on patient outcomes and costs for non-elective major lower extremity amputations (LEA). MethodsThe 2019–2021 Florida Agency for Health Care Administration database was queried for adult patients who underwent non-elective major LEA. Per-patient inflation-adjusted costs were collected. Patient cohorts were established based on Florida COVID-19 mortality rates: COVID-heavy (CH) included nine months with the highest mortality, COVID-light (CL) included nine months with the lowest mortality, and pre-COVID (PC) included nine months before COVID (2019). Outcomes included in-hospital patient outcomes and hospitalization cost. Results6132 patients were included (1957 PC, 2104 CH, and 2071 CL). Compared to PC, there was increased patient acuity at presentation, but morbidity (31%), mortality (4%), and length of stay (median 12 [8–17] days) were unchanged during CH and CL. Additionally, costs significantly increased during the pandemic; median total cost rose 9%, room costs increased by 16%, ICU costs rose by 15%, and operating room costs rose by 15%. When COVID-positive patients were excluded, cost of care was still significantly higher during CH and CL. ConclusionsDespite maintaining pre-pandemic standards, as evidenced by unchanged outcomes, the pandemic led to increased costs for patients undergoing non-elective major LEA. This was likely due to increased patient acuity, resource strain, and supply chain shortages during the pandemic. Key messageWhile patient outcomes for non-elective major lower extremity amputations remained consistent during the COVID-19 pandemic, healthcare costs significantly increased, likely due to increased patient acuity and heightened pressures on resources and supply chains. These findings underscore the need for informed policy changes to mitigate the financial impact on patients and healthcare systems for future public health emergencies.

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

OBJECTIVEStaged 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. METHODSData from patients who underwent major LEA from 2015 to 2021 was collected retrospectively. The study included all patients undergoing below-, through-, or above-knee amputations. Next, patients who had OGA prior to a definitive amputation were selected. Patients who died before amputation closure were excluded. Post-amputation outcomes such as surgical site infection (SSI), postoperative sepsis, postoperative ambulation, hospital length of stay (LOS), and 30-day, 1-year, and 5-year mortality were reviewed. The study cohort was stratified by demographics and comorbidities. Receiver operating characteristic (ROC) curve analysis was performed to determine the time of closure (TOC) cut-off value. Univariate and multivariate analysis was performed to assess outcomes. Statistical significance was set at p < 0.05. RESULTOf 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 (IQR) 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 (AUC) (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 (DVT) complication. There was no significant difference in LOS, postoperative SSI, sepsis, and ambulation between the two subgroups of obese patients. Multivariable analysis showed that gender, CKD, and postoperative ambulation independently predict overall mortality in obese patients. CONCLUSIONTOC 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.

Risk Factors for Lower Extremity Minor Amputation Conversion to Major Amputation

Minor lower extremity amputations have become an important part of the limb salvage approach but are not as benign as previously thought. This study investigates the difference in outcome between toe/ray versus midfoot amputations and the risk factors for major amputation conversion associated with each procedure. We performed retrospective chart review of foot amputation patients at a single tertiary care medical center with a primary end point of conversion to major amputation and secondary end points of one-year wound healing and mortality rate. We collected data on relevant medical comorbidities, non-invasive vascular imaging, revascularization, repeat amputations, wound healing rate, and one-year mortality. Patients were separated into toe/ray amputations versus midfoot amputation groups and compared using descriptive statistics, Chi Squared tests, Cox proportional hazards, and a multivariate logistic regression model. A total of 375 amputations were included in the analysis. 65.3% (245 patients) included toe/ray amputations and 34.7% (130 patients) included midfoot amputations. We compared these two cohorts with regard to their rate of conversion to repeat minor and/or major amputation in addition to overall mortality. The toe/ray group underwent more repeat minor amputations within one year after index amputation (34.7% vs. 21.5%, p=0.008) and wound healing (epithelization) at 90 days was also higher in this group. The midfoot group had a higher conversion to major lower extremity amputation within one year on univariate analysis (20.8 vs. 6.9%, p<0.001). Overall one-year mortality was 6.17% and there was no significant difference between groups. While there is a consistency with previous studies that found no significant overall difference in mortality between types of minor LEA, we have extended this previous work by demonstrating the independent risk factors for conversion to major amputation between types of minor LEA. Comparing these two groups will assist surgeons in choosing the appropriate level of amputations and will enhance patient's understanding of their chance of wound healing and risk of repeat amputation.

Risk Factors for Major Lower Limb Amputation and Effect of Endovascular Revascularization in Patients with Diabetic Foot Wound.

Major lower extremity amputation (LEA) such as below-knee or above-knee amputations can result in more physical disabilities and poorer socioeconomic functions than minor LEAs in diabetic foot ulcer (DFU). Therefore, identification of risk factors for major LEA and investigation of effectiveness of endovascular revascularization are critical for prevention and better prognosis of DFU patients. From January 2014 to December 2017, a total of 125 patients with DFU treated with any level of amputation were included in this study. Demographic, diabetes-related, DFU-related and -relevant laboratory information were investigated to predict major amputation. To identify risk factors for major amputation, logistic regression analysis was performed for each variable. The effectiveness of endovascular revascularization treatment was analyzed using Kaplan-Meier survival curves. Major amputation was performed for 22 of 125 patients. Multivariate logistic regression analysis indicated that DM duration, peripheral arterial occlusive disease (PAOD) previous amputation, abscess, Wagner grade, CRP and albumin were significant risk factors for major amputation in DFU patients. PAOD was the most important risk factor. Major amputation-free survival rate at 5years was 97.4% in a non-PAOD group, 58.3% in a PAOD without revascularization group, and 88.0% in a PAOD with revascularization group, showing statistically significant differences among them. The duration of DM, PAOD, previous amputation, abscess, Wagner grade, CRP and albumin were major risk factors for major LEA in DFU patients. The most valuable and critical finding was that revascularization in diabetic foot patients with PAOD significantly improved major amputation-free survival rates.

Ultrasound-Guided Percutaneous Cryoneurolysis for Perioperative Analgesia Following Major Lower Extremity Amputation: A Randomized, Participant- and Observer-Masked, Sham-Controlled Pilot Study.

Extremity amputations are associated with pain in both the residual limb and the phantom limb. This pain, which is often debilitating, may be prevented by excellent perioperative pain control. Ultrasound-guided percutaneous cryoneurolysis is an analgesic modality offering pain control for weeks or months following surgery. This treatment has not been compared to the sham procedure for large nerves (e.g., femoral and sciatic) to provide preoperative analgesia. We therefore conducted a randomized, controlled pilot study to evaluate the use of this modality for the treatment of pain following amputation to (1) determine the feasibility of and optimize the study protocol for a subsequent definitive clinical trial; and (2) estimate analgesia and opioid reduction within the first postoperative weeks. A convenience sample of seven patients undergoing lower extremity amputation were randomized to receive either active cryoneurolysis or a sham procedure targeting the sciatic and femoral nerves in a participant-masked fashion. This was a pilot study with a relatively small number of participants, and therefore the resulting data were not analyzed statistically. Compared to the participants who received sham treatment (n=3), those who underwent active cryoneurolysis (n=4) reported lower pain scores and decreased opioid consumption at nearly all time points between days one and 21 following amputation. Ultrasound-guided percutaneous cryoneurolysis of the femoral and sciatic nerves prior to lower extremity amputation appears feasible and potentially effective. The data from this pilot study may be used to power a definitive randomized clinical trial.

Risk Prediction of Diabetic Foot Amputation Using Machine Learning and Explainable Artificial Intelligence.

Diabetic foot ulcers (DFUs) are serious complications of diabetes which can lead to lower extremity amputations (LEAs). Risk prediction models can identify high-risk patients who can benefit from early intervention. Machine learning (ML) methods have shown promising utility in medical applications. Explainable modeling can help its integration and acceptance. This study aims to develop a risk prediction model using ML algorithms with explainability for LEA in DFU patients. This study is a retrospective review of 2559 inpatient DFU episodes in a tertiary institution from 2012 to 2017. Fifty-one features including patient demographics, comorbidities, medication, wound characteristics, and laboratory results were reviewed. Outcome measures were the risk of major LEA, minor LEA and any LEA. Machine learning models were developed for each outcome, with model performance evaluated using receiver operating characteristic (ROC) curves, balanced-accuracy and F1-score. SHapley Additive exPlanations (SHAP) was applied to interpret the model for explainability. Model performance for prediction of major, minor, and any LEA event achieved ROC of 0.820, 0.637, and 0.756, respectively, with XGBoost, XGBoost, and Gradient Boosted Trees algorithms demonstrating best results for each model, respectively. Using SHAP, key features that contributed to the predictions were identified for explainability. Total white cell (TWC) count, comorbidity score and red blood cell count contributed highest weightage to major LEA event. Total white cell, eosinophils, and necrotic eschar in the wound contributed most to any LEA event. Machine learning algorithms performed well in predicting the risk of LEA in a patient with DFU. Explainability can help provide clinical insights and identify at-risk patients for early intervention.

The Effect of Limb Salvage Efforts in Different Age Groups: Relationships Between Major and Minor Amputations

“Limb salvage” efforts, such as performing minor amputations before infections spread proximally from the foot to decrease major lower extremity amputation, are an important part of healthcare today. It is unclear whether these efforts are preventing the number of major amputations and improving patients’ quality of life and the cost-effectiveness of the U.S. healthcare system. Rates of non-traumatic lower extremity amputation (NLEA) among patients with diabetes decreased in the early 2000s but rebounded in the 2010s. We analyzed the proportion of major amputations and differences in amputation rates between age groups in Texas. Patient data was extracted from the Texas Hospital Discharge Data Public Use Data File. Population estimates were obtained from the Texas Population Estimates Program from 2011 to 2015 and from intercensal estimates provided by the U.S. Census Bureau from 2006 to 2010. Raw numbers of minor, major, and all NLEA surgeries and the ratio of major amputations to total amputations per year were reported for each age group. Poisson regression and Joinpoint analyses were performed to capture these changes in trends. Rates of amputations increased, with significant decreasing relative prevalence of major amputations. Patients aged 45 to 64 with diabetes are likely driving these increases. Rates of lower extremity amputation in patients with diabetes increased from 2009 to 2015. This holds for all and minor amputations. In contrast, the ratio of major to all amputations decreased from 2010. Utilization of major and minor amputation differs between age groups, remaining stable in the youngest subjects, with minor amputation rates increasing in those aged 45 to 64.