Purpose: Study the possible etiology of the deep inferior epigastric perforator (DIEP) flap global venous congestion in breast reconstruction.

Background: Although venous congestion in Zone I, II and III of the DIEP flap occurs rarely, its cause is really unknown. After no usual causes identified, a venous anastomosis between the superficial epigastric vein and any vein at the recipient site is the current treatment.

Materials and Methods: First, ten fresh cadaver dissections showed that the superficial (SIEV) and deep inferior epigastric vein (DIEV) systems were well connected, but the valves within the SIEV could prevent retrograde drainage into the DIEV. Normally, the SIEV valves directed blood from the tissue superficial to scarpa into femoral vein. In DIEP flap, the usual SIEV flow was interrupted. Hence, a retrograde flow within the SIEV had to occur to drain into the DIEV system. Larger SIEV might have competent valves to prevent such necessary retrograde flow.

Then, we proceeded with our study 21 DIEP flaps for breast reconstruction in 12 consecutive patients. Average patient age was 34 years and reconstructed breast mound ranged from B to D cup. In each flap, the largest SIEV was exposed, measured, canulated, and continuously monitored by a Hewlett Packard transducer during the entire flap dissection. Pressure within the SIEV in mm Hg was recorded and correlated with SIEV diameter, flap capillary refill and flap outcome. The number of perforators per flap ranged from 1 to 3 and a mean of 2.

Results: Twenty-one flaps had a mean SIEV diameter of 1.7 mm, and a range of 0.08 to 2.5 mm. Mean initial, peak and end pressure in the SIEV were 19, 33, and 15 mm Hg respectively. Two blue flaps were found to have a capillary refill under one second, elevated peak pressure of 46 mm Hg in the 1.5 mm SIEV and 50 in the other 2 mm SIEV. With the dissection completed and flap still perfused by the native deep inferior epigastric vessels, the venous congestion spontaneously resolved as the SIEV pressure dropped to 15 and 21 mm Hg. Microvascular anastomoses were performed as usual. No flap loss occurred due to no additional venous anastomosis.

Conclusion: Competent SIEV valves may play a role in the rare global venous congestion of DIEP flaps.