Intraoperative Vascular Findings Predict Salvage Outcome in Free Flaps with Circulatory Compromise

Microsurgical free tissue transfer has become a reliable technique. Nevertheless, 5 to 25% of transferred flaps require re-exploration due to circulatory compromise. This reported study was conducted to evaluate the relationship between vascular findings on re-exploration of compromised free flaps and their correlation with salvage outcome.

Between January 2002 and June 2003, 1142 free flap transfers were performed and 114 flaps (10.0%) required re-exploration due to circulatory compromise. Through a retrospective chart review, the causes of circulatory compromise were analyzed and divided into different categories. The flap outcome was classified as complete salvage, partial failure, and complete failure, and correlations were made between the different categories of vascular compromise and the effect on outcome.

Seventy-one flaps (62.3%) were completely salvaged; 24 (21.1%) underwent partial failure; and 19 (16.7%) underwent complete failure. Eighty-eight flaps (77.2%) were found on re-exploration to have obstructed pedicles, 62 (70.5%) of which were completely salvaged. Twenty-eight flaps were found to have a patent pedicle on exploration of which only 9 (34.6%) were completely salvaged. The difference between the salvage rate in the obstructed vs. non-obstructed group was statistically significant (p = 0.009). Of the flaps with obstructed pedicles, 62 (70.5%) had evidence of intralumenal thrombosis, and 26 (29.5%) had other causes (pedicle compression, n = 18 (69.2%), pedicle kinking, n = 6 (23.1%), and vasospasm, n = 2 (7.7%)). The complete salvage rate was significantly higher for flaps with an obstructed pedicle without evidence of thrombosis (84.6% vs. 61.3%, p = 0.003). Flaps with both arterial and venous occlusion had a significantly worse salvage result (30.8%), compared to flaps with isolated arterial occlusion (64.5%) and flaps with isolated venous occlusion (83.7%) (p = 0.001). Compromised flaps with patent pedicles (n = 26) were classified into inset-related problems (n = 3, 11.5%) and flap-related problems (n = 23, 88% - absent, small, or traumatized perforator). Flaps with inset problems had a significantly higher complete salvage rate (100% vs. 34.8%, p = 0.035).

Findings on exploration can have a significant impact in predicting flap salvage outcome. The ability to predict flap outcome based on intraoperative findings in re-exploration can significantly improve the understanding of flap behavior and can potentially impact on final results.