Efficacy of venous supercharging of the deep inferior epigastric perforator flap in a rat model.

BACKGROUND: An insidious risk with the use of muscle perforator flaps is the possibility of venous outflow compromise. Congestion in deep inferior epigastric perforator (DIEP) flaps in particular is not infrequent. On an empiric basis, their salvage has been accomplished by augmenting venous drainage through alternative outflow tracts. The validity of this clinical maneuver can now best be tested in a rat DIEP flap model.
METHODS: The rat DIEP flap is a modification of the rat ventral abdomen flap. Flap perfusion can be based on a single rectus abdominis musculocutaneous perforator. No muscle is included with the flap. Three groups of five male Sprague-Dawley rats each were used. The conventional DIEP flap group had only a solitary perforator artery and venae comitantes and served as the control. The contralateral superficial inferior epigastric vein was included with the flap in the other two groups as a distinctly separate venous outflow tract. The latter two groups differed in that the perforator venae comitantes were either retained or deleted.
RESULTS: Mean flap survival in the control DIEP flap group was 80.8 +/- 16.3 percent. Retention of the contralateral superficial inferior epigastric vein resulted in a statistically significant enhancement in flap viability (p < 0.027) whether the perforator venae comitantes were left intact (99.8 +/- 0.4 percent) or had been intentionally ablated (99.6 +/- 0.5 percent).
CONCLUSIONS: Venous supercharging of the rat DIEP flap ensures greater flap survival. As a corollary, this supports the efficacy of prior anecdotal experiences in which an alternative venous outflow tract, preferably from the superficial system, had been used to overcome venous congestion. It is advisable for any muscle perforator flap to always try to retain a second outflow source to allow the potential for venous supercharging, if later indicated.