DIE, SIE, or TRAM: A Systematic Approach to Flap Selection

Multiple techniques exist for transfer of lower abdominal tissue for breast reconstruction. Unlike the pedicled TRAM flap, free tissue transfer minimizes disruption of the abdominal donor site. However, the decision to proceed with a free TRAM, DIEP, or an SIEA flap is not arbitrary. The purpose of this report was to outline a strategy for flap selection, particularly in cases of previous abdominal surgery that may impact upon lower abdominal vascularity. A microsurgeon's first 3-year experience with free flap breast surgery was reviewed, noting previous abdominal scars, flap selection, including dominant perforator location in the case of the DIEP, and complications including fat necrosis.

Seventy–two flaps were used in 53 patients (19 bilateral). Free tissue transfer was possible in all but two patients (unsuitable recipient vessels, transected deep inferior epigastrics from lower lateral paramedian scar). No other scars precluded free tissue transfer. There were 19 free TRAM, 47 DIEP, and 3 SIEA flaps. The small number of SIEA flaps represents its recent addition to the reconstructive armamentarium. Currently, when a hemi-TRAM distribution is required, the SIEAs are investigated first. If they appear adequate, the flap is isolated to several deep system perforators which are temporarily occluded. If the flap remains well–perfused, it is raised as an SIEA flap. If it becomes compromised or if the superficial system is inadequate/absent, the flap is converted to a DIEP or free TRAM depending on perforator size.

When Zones 1–3 are required, a DIEP or a TRAM are preferentially used, since experience with SIEA flaps in head and neck reconstruction failed to reveal reliable perfusion across the midline. A free TRAM is preferred when Zones 1–4 are required. Zone 4 may be unreliable in a DIEP, unless the contralateral superficial venous system is preserved for supercharging.

With respect to scars, previous laparoscopy had no effect on flap choice. However, with lower midline incisions, medial row perforators were less likely to be available for supplying the DIEP, so that lateral row perforators were usually selected.

Pfannensteil incisions were important. Lower lateral and mid–to–low medial row perforators were not reliable perforators upon which to base DIEP flaps and resulted in increased incidence of fat necrosis. A short Pfannensteil incision, however, could result in a preserved and useful SIEA system.

This early experience has been used to develop conservative guidelines for flap dissection and selection for breast reconstruction, particularly in cases of previous abdominal surgery.