Delineating the risk factors of venous congestion: An analysis of 455 deep inferior epigastric perforator flaps with radiographic correlation.

[BACKGROUND] Venous congestion occurs in 2-15% of DIEP flaps for breast reconstruction. We previously showed that thicker suprascarpal fat pads are associated with increased SIEV caliber and may, by extension, indicate a dominant superficial venous system. In this study, we aim to provide clinical correlation and to determine the risk factors of venous congestion in order to identify high-risk patients who may benefit from prophylactic SIEV dissection.

[METHODS] An IRB-approved retrospective study was performed in patients who underwent DIEP flap reconstruction from August 2011 to August 2020. Radiographic measurements of suprascarpal fat pad thickness and SIEV diameter were collected per hemi-abdomen from preoperative imaging. The statistical analysis explored whether certain variables were associated with venous congestion.

[RESULTS] A total of 258 patients underwent 455 DIEP flaps. Suprascarpal fat pad thickness was positively correlated with SIEV diameter (r = 0.51, p<0.001), each with a mean caliber of 19.8 mm and 2.5 mm, respectively. Seven flaps (1.5%) developed venous congestion, with five requiring SIEV salvage and secondary venous anastomosis. Congested flaps had significantly thinner suprascarpal fat pads (12.3 vs. 20.0 mm, p = 0.043). All six congested flaps with imaging had suprascarpal thickness less than 18 mm, compared to 182 out of 335 non-congested flaps with imaging (p = 0.035).

[CONCLUSIONS] The risk of venous congestion following DIEP flap reconstruction is significantly increased with thinner suprascarpal fat pads, suggesting that the mechanism of venous congestion may not be limited to superficial venous dominance. We recommend prophylactic SIEV dissection in all patients with suprascarpal fat pad thickness less than 18 mm.