Predictors For Secondary Amputation Following Lower Extremity Free Tissue Transfer In Comorbid Patients With Chronic Lower Extremity Wounds
Romina Deldar, MD1, Brian N. Truong, BS2, Nisha Gupta, MS2, John D. Bovill, BS2, Zoe K. Haffner, BS1, Adaah A. Sayyed, BS1, Christopher E. Attinger, MD1, Karen K. Evans, MD1.
1MedStar Georgetown University Hospital, Washington, DC, USA, 2Georgetown University School of Medicine, Washington, DC, USA.
PURPOSE: Non-healing lower extremity (LE) wounds often require surgical intervention. Historically, there has been debate regarding limb salvage with microsurgical free tissue transfer (FTT) versus primary amputation in comorbid patients with non-traumatic LE wounds. Despite free flap success rates approaching 99%, a subset of patients with successful FTT reconstruction will eventually require secondary amputation. This can profoundly impact patientsí psychological, financial, and physical health. Determining the degree to which a patientís comorbidities and surgical factors increase risk of failed limb salvage may guide surgeons to perform the surgery that will produce the best possible functional outcome. The aim of this study is to identify risk factors for secondary major amputation following FTT in comorbid patients with non-traumatic LE wounds.
METHODS: Retrospective review of all patients who underwent LE free flap surgery between 2011 to 2021 was conducted. Patient demographics, baseline comorbidities, perioperative data, microsurgical outcomes and long-term outcomes were examined. Primary outcomes of interest were flap success, limb salvage, and ambulatory status. Variables that conferred risk for eventual amputation were examined by multivariate regression analysis. Odds ratios (OR) with 95% confidence intervals were calculated for each risk factor. Statistical significance was set at vales of p < 0.05
RESULTS: A total of 247 patients underwent free flaps to LE were performed in a 10-year period. Average age and body mass index were 56.9 years and 29.4 kg/m2, respectively. Immediate microsurgical success rate was 97.2% (n=240). At average follow-up duration of 21.3 months (range, 0.5 to 114.6 months), 88.7% (n=219) had successful limb salvage, and 28 patients (11.3%) required major amputation. Diabetes (75.0% vs. 50.2%, p=0.013) and end-stage renal disease (ESRD) (14.3% vs. 3.2%, p=0.025) were more prevalent in future amputees. Likewise, Charcot arthropathy was significantly higher in the amputation group (17.9% vs. 5.9%, p=0.039). Preoperative albumin levels were also lower in patients who underwent eventual amputation compared to the limb salvage group (2.5 vs. 3.2 g/dL, p<0.001). Limb salvage patients achieved higher ambulatory rates compared to the amputation group (93.1% vs. 78.6%, p=0.003). Risk factors for amputation were albumin < 3.2 g/dL (OR 7.13, p=0.003) and ESRD (OR: 5.08, p=0.035).
CONCLUSION: This is the largest study to identify independent risk factors for major amputation in patients who have undergone FTT reconstruction for non-traumatic LE wounds. Hypoalbuminemia and ESRD were identified as independent predictors of secondary amputation after free flap lower limb salvage. These findings may aid in patient selection for free flap limb salvage versus primary amputation. Future multi-institutional studies are warranted to possibly identify additional risk factors.
|Amputation(n=31)||Limb Salvage(n=224)||p-value||Odds Ratio||95% Confidence Interval||p-value|
|Diabetes||21 (75.0%)||110 (50.2%)||0.013||1.39||0.5-3.7||0.511|
|End-stage renal disease||4 (14.3%)||7 (3.2%)||0.025||5.08||1.1-23.0||0.035|
|Albumin < 3.2 g/dL||24 (77.4%)||107 (48.9%)||0.001||7.13||1.9-26.2||0.003|
|Osteomyelitis||22 (78.6%)||129 (58.9%)||0.044||2.07||0.8-5.6||0.153|
|Charcot arthropathy||5 (17.9%)||13 (5.9%)||0.039||2.53||0.7-8.8||0.143|
|Flap Success||27 (96.4%)||213 (97.3%)||0.574||0.46||0.1-4.7||0.511|
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