Risk Factors for Lower Extremity Minor Amputation Conversion to Major Amputation

BACKGROUND

Minor lower extremity amputations (LEAs) 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.

METHODS

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 1-year wound healing and mortality rate. We collected data on relevant medical comorbidities, noninvasive vascular imaging, revascularization, repeat amputations, wound healing rate, and 1-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.

RESULTS

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 2 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 1 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 LEA within 1 year on univariate analysis (20.8 vs. 6.9%, P < 0.001). Overall 1-year mortality was 6.17% and there was no significant difference between groups.

CONCLUSIONS

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 2 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.

Minor amputation after revascularization in chronic limb-threatening ischemia: What is the optimal timing?

OBJECTIVES

Patients with chronic limb-threatening ischemia (CLTI) have a high risk of lower limb amputation and loss of walking independence. Minor amputations play a key role in ensuring walking independence and they represent a challenge in terms of timing and level for vascular surgeons. A major cause of re-amputation is a defect in wound healing and a possible predictor of re-amputation for non-healing wounds could be the incorrect timing of minor amputation after revascularization. The lack of evidence in the literature leads to a wide variability of choices in clinical practice. The purpose of this study was to try to find the optimal timing analysing the risk of re-amputation in CLTI patients who have undergone successful revascularization and minor amputation focussing on timing of minor amputation.

METHODS

We conducted a single centre retrospective analysis on a cohort of 151 patients consecutively admitted to our hospital for CLTI (Rutherford 5) between January 2014 and April 2022. All the enrolled patients underwent successful revascularization of lower limbs and a minor amputation for dry acral necrosis. The characteristics of the patients and the revascularization procedures were collected and analysed. Patients were divided into two groups based on the timing of minor amputation performed before (group 1) or after the day (group 2) that best predicts the risk of re-amputation according to a Receiver Operating Characteristic (ROC) curve analysis. The primary outcome of this study was the risk of re-amputation during the first 60 days of follow-up after a primary minor amputation, with revascularization still effective. The impact of the timing of minor amputation after revascularization, the type of revascularization and the presence of risk factors known to prolong the wound healing process were evaluated in a uni- and multi-variable logistic regression model.

RESULTS

Systemic hypertension, and type of revascularization (i.e. open vs endovascular) were independent predictors of the risk of re-amputation at 60 days (HR 4.26, 95% CI 1.30-14.04, p = .017 and HR 2.35, 95% CI 1.16-4.78, p = .018, respectively). Moreover, time ≤14 days between revascularization and first amputation was associate with a clear, albeit not statistically significant, trend toward increased risk of re-amputation (HR 2.09, 95% CI 0.97-4.51, p = .06).

CONCLUSIONS

In a cohort of patients who underwent a successful revascularization for CLTI and a minor amputation for dry gangrene in the first 14 days after revascularization, a higher -although not significant-risk of re-amputation was reported. In this cohort of patients, a delayed demolitive procedure should be considered to allow better tissue perfusion and to reduce the risk of re-amputation.

Factors Associated with Healing Outcomes in Primary Care Patients with Diabetic Foot Ulcers: A Retrospective Study in a Multiethnic Sample

OBJECTIVE

To identify and determine patient- and ulcer-related factors associated with healing outcomes within 3 months for patients with diabetic foot ulcer (DFU) in a multiethnic primary care sample.

METHODS

Retrospective data were collected over 3 months from 520 primary care patients with a DFU between April 1, 2016 and March 31, 2017. Multivariable prevalence ratios (PRs) were calculated using Poisson regression to find associations between patient- and ulcer-related factors and healing outcomes.

RESULTS

Most patients were male (66%) and Chinese (49.8%) and had a diabetes mellitus duration longer than 5 years (81.8%). Toe ulcers (64%) were most common. Healing occurred for 33.9% of participants; 19.1% and 1.5% underwent minor and major amputation, respectively. Wound sizes between 1 and 10 cm2 (PR, 0.61; 95% confidence interval [CI], 0.46-0.76; P < .001) and over 10 cm2 (PR, 0.55; 95% CI, 0.33-0.76; P = .003), ulcer duration 6 months or longer (PR, 0.36; 95% CI, 0.19-0.53; P < .001), ischemic ulcers (PR, 0.54; 95% CI, 0.22-0.86; P = .044), and neuroischemic ulcers (PR, 0.73; 95% CI, 0.53-0.93; P = .027) were negatively associated with healing outcomes. Women were more likely to experience healing (PR, 1.18; 95% CI, 0.91-1.45; P = .157).

CONCLUSIONS

Ulcer healing varied by sex and was affected by wound size, wound duration, and ischemic etiology, regardless of ethnicity. Prompt attention to these risk factors may reduce healing time. Further studies are warranted to elucidate the mechanism underlying sex differences in association with DFU healing.

Evaluation of Clinical Outcomes Following Minor Amputations in Australia - An Important Consideration for Timing of Revascularisation

BACKGROUND

Vascular patients with tissue loss requiring minor amputations could be an early sign of a terminal event. The long-term outcomes and timing of revascularisation for these patients are not well-studied. The aim of this study was to determine the clinical outcomes following minor amputations. Primary outcomes were functional status, limb loss, and mortality. Secondary outcomes compared immediate and delayed revascularisation.

METHODS

A retrospective analysis of 200 vascular patients who required minor amputations at Austin Hospital, Melbourne was performed over 5 years. Demographics, details of revascularisation, functional status, and clinical outcomes such as recurrent tissue loss, limb loss and death were recorded.

RESULTS

Of the entire cohort requiring minor amputations, 118 (59%) patients underwent revascularisation. 111 (94%) revascularisation procedures were performed within 90 days of minor amputation. Over all 5-year limb preservation was 89.9%. Patients who required revascularisation were not statistically significantly more at risk for limb loss at 5 years [13.6% vs. 6.6%; P=0.08]. Limb salvage at 1 year was not different between groups revascularized before and after amputation [89.5% vs. 90.9%; P=0.70]. Over all 5-year mortality rate was 50%. In the diabetic subset, those who had revascularisation after minor amputation had a greater 5-year mortality [67.9% vs. 50%; P=0.03]. A scoring system based on risk factors was developed but was not reliable based on the study data.

CONCLUSIONS

The data from this study suggest that patients with diabetes who undergo revascularisation after minor amputation have worse outcomes than those revascularised prior to minor amputation. A predictive model applied at presentation could help detect high-risk patients but requires further work.

Struggling for normality: experiences of patients with diabetic lower extremity amputations and post-amputation wounds in primary care

Aim:

To explore the experiences of patients living with diabetic lower extremity amputation (DLEA) and its post-amputation wound in primary care.

Background:

DLEA, including both minor and major amputation, is a life-altering condition that brings numerous challenges to an individual’s life. Post-amputation physical wound healing is complicated and challenging because of wound dehiscence and prolonged healing times. Understanding patients’ experiences after DLEA with a post-amputation wound will enable healthcare professionals to develop interventions to assist patients in physical healing and psychosocial recovery.

Methods:

This study employs a qualitative design using interpretative phenomenological analysis (IPA). A purposive maximum variation sample of nine patients who had had lower extremity amputations and post-amputation wound attributed to diabetes in the previous 12 months was recruited from a primary care setting in Singapore. Semi-structured audio recorded one-to-one interviews with a duration of 45–60 min each were conducted between September 2018 and January 2019. The interviews were transcribed verbatim and analysed using IPA.

Findings:

The essential meaning of the phenomenon ‘the lived experiences for patients with DLEA and post-amputated wound’ can be interpreted as ‘struggling for “normality”’ which encompasses four domains of sense making: physical loss disrupted normality, emotional impact aggravated the disrupted normality, social challenges further provoked the disrupted normality, and attempt to regain normality. The study highlights the complex physical and psychosocial transition facing patients after DLEA before post-amputation wound closure. In primary care, an amputation, whether minor or major, is a life-altering experience that requires physical healing, emotional recovery, and social adaptation to regain normality. Patients living with DLEA and a post-amputation wound may benefit from an interdisciplinary team care model to assist them with physical and psychosocial adjustment and resume normality.

Predictors of Major Adverse Limb Events after Open Forefoot Amputation in Patients with Chronic Limb-Threatening Ischemia

BACKGROUND

Management of patients with chronic limb-threatening ischemia (CLTI) and extensive foot necrosis presents a challenge for limb salvage. Our study evaluates preoperative risk factors that contributed to durability and efficacy of limb salvage after open transmetatarsal amputation (TMA) in patients with critical limb-threatening ischemia.

METHODS

We abstracted data from patients who underwent open TMA at Los Angeles County-University of Southern California Medical Center and Keck Hospital of University of Southern California from 2009 to 2018. Multivariable logistic regression analysis, adjusting for preoperative risk factors, was used to examine predictors of major adverse limb events (MALE). The aim was to evaluate outcomes following open TMA with MALE as the primary outcome. Our hypotheses were that outcomes would be worse for patients with foot infections and renal failure.

RESULTS

Forty-three open TMAs were done in 39 patients during the study period. The cohort had a mean age of 63 ± 11.6 years, 89% had a history of diabetes, 95% hypertension (HTN), 54% had end-stage renal disease (ESRD), and 26% were current smokers. MALE occurred in 39% of the cohort. Sex, race, indication, HTN, smoking status, and history of prior ipsilateral revascularization or minor amputations were not associated with MALE (P > 0.05). Multivariate logistic regression found ESRD to be an independent predictor of MALE (odds ratio 7.43, 95% confidence interval 1.12-49.17, P = 0.038) after adjusting for clinically significant covariates.

CONCLUSIONS

Open TMA provides acceptable rates of limb salvage for complex patients with CLTI. ESRD is an independent risk factor for MALE following open TMA in these patients. Vigilant follow-up is essential for this morbid patient population given poorer outcomes after forefoot amputation.