Proximal and Distal Recipient Vessels Are Associated with Equivalent Outcomes in Lower Extremity Trauma Free Flap Reconstruction: A 312 Patient Series and Systematic Review
William J. Rifkin, BA, John T. Stranix, MD, Zachary M. Borab, MD, Adam Jacoby, MD, Z-Hye Lee, MD, Lavinia Anzai, MD, Daniel J. Ceradini, MD, Vishal Thanik, MD, Pierre B. Saadeh, MD, Jamie P. Levine, MD.
Hansjörg Wyss Department of Plastic Surgery, NYU Langone Health, New York, NY, USA.
PURPOSE: Recipient vessels proximal to the zone of injury have traditionally been preferred in traumatic lower extremity free flap reconstruction. This is due to presumed changes in the caliber and quality of vessels within and distal to the site of trauma that may result in less favorable outcomes and higher rates of flap failure. However, more recent data have shown mixed outcomes when performing anastomoses distal to the zone of injury. This study investigates the impact of lower extremity recipient vessel location on free flap outcomes.
METHODS: Retrospective review of our institutional flap registry from 1979-2016 identified 806 lower extremity free flaps; 312 soft tissue free flaps for open tibia fracture coverage met inclusion criteria. Patient demographics, flap characteristics, and outcomes were examined. Statistical analysis was performed using Chi-square and Student's t-test, as well as binary logistic regression to control for confounding variables. A systematic review of existing literature was performed to identify articles evaluating anastomosis location and free flap outcomes in traumatic lower extremity repair; simple pooled analysis as well as a weighted comparative analysis were performed.
RESULTS: Within our cohort, the majority of anastomoses, 252 (80.7%), were performed proximal to the zone of injury, while 60 (19.3%) anastomoses were performed distally. Distal anastomoses were not associated with increased rates of total flap failure (9.3% vs. 9.3%; p=0.815) or partial flap failure (7.4% vs. 11.9%; p=0.978) compared to proximal anastomoses when controlling for confounding variables, such as presence of arterial injury, flap type, and time from injury to coverage. Furthermore, distal anastomoses were not associated with increased rates of operative take backs (19.6%) compared to proximal anastomoses (23.8%; p=0.356). The rates of arterial (p=0.469) and venous complications (p=0.348) were similar between proximal and distal groups. Systematic review yielded 11 articles with 1245 proximal and 127 distal anastomoses for comparison. Pooled analysis of all studies (p=0.58) and weighted comparative analysis of direct comparison studies (p=0.39) found no difference in flap failure rates between proximal and distal groups.
CONCLUSION: There was no statistically significant difference in complication or flap failure rates for anastomoses performed proximal or distal to the zone of lower extremity injury. These findings suggest that as long as the recipient vessels are outside the zone of injury, selection should be based on pedicle length, ease of vessel exposure, and adequate inflow/outflow rather than simply a proximal or distal orientation relative to the injury.
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