Importance of lateral row perforator vessels in deep inferior epigastric perforator flap harvesting

Free flaps based on perforator vessels, and in particular the deep inferior epigastric perforator (DIEP) flap, are currently being applied in abdominal reconstruction. However, one of the main disadvantages is the operative complexity. Through anatomical study and clinical experience with the DIEP flap in breast reconstruction, the intramuscular path of the perforator vessels was comparatively studied, to establish the main anatomical parameters that favor procedure planning. Thirty DIEP flaps from 15 fresh cadavers were used. The number, location, and intramuscular course of the perforator vessels were determined. In addition, an initial clinical study was performed in 31 patients using 35 DIEP flaps in breast reconstruction. The number, location, and the intramuscular course of the perforators were assessed. In the cadaver study, 191 perforator vessels were detected (6.4 vessels per flap). Thirty-four percent were located in the lateral row, and the rectilinear course was observed in 79.2 percent of these vessels. In the medial row, only 18.2 percent of the perforator vessels presented this configuration (p = 0.001). Thirty-one patients underwent DIEP flap breast reconstruction, with 26 immediate and four bilateral reconstructions. In 22 of 35 flaps (62.9 percent), two perforators were used. In 25 flaps (71.4 percent), the lateral row perforators with a rectilinear course were observed. Mean operative time was 7 hours and 37 minutes. Two total flap losses and two partial necroses were observed. The majority of the lateral row perforators presented a rectilinear intramuscular course, which was shorter than that of the medial row perforators. This anatomical characteristic favors dissection with reduced operative time and vascular lesion morbidity, resulting in an important anatomical parameter for DIEP flap harvesting.     

Free anterolateral thigh adipofascial perforator flap

The anterolateral thigh adipofascial flap is a vascularized flap prepared from the adipofascial layer of the anterolateral thigh region. It is a perforator flap based on septocutaneous or musculocutaneous perforators of the lateral circumflex femoral system. With methods similar to those used for the free anterolateral thigh flap, only the deep fascia of the anterolateral thigh and a 2-mm-thick to 3-mm-thick layer of subcutaneous fatty tissue above the fascia were harvested. In 11 cases, this flap (length, 5 to 11 cm; width, 4 to 8 cm) was used for successful reconstruction of extremity defects. Split-thickness skin grafts were used to immediately resurface the adipofascial flaps for eight patients, and delayed skin grafting was performed for the other three patients. The advantage of the anterolateral thigh adipofascial flap is its ability to provide vascularized, thin, pliable, gliding coverage. In addition, the donor-site defect can be closed directly. Other advantages of this flap, such as safe elevation, a long wide vascular pedicle, a large flap territory, and flow-through properties that allow simultaneous reconstruction of major-vessel and soft-tissue defects, are the same as for the conventional anterolateral thigh flap. The main disadvantage of this procedure is the need for a skin graft, with the possible complications of subsequent skin graft loss or hyperpigmentation.     

Two options for perforator flaps in the flank donor site: latissimus dorsi and thoracodorsal perforator flaps

Two types of perforators, septocutaneous and musculocutaneous, are found in the same donor site of the flank area, and two perforator flaps based on each perforator are clinically available. Therefore, it is necessary to distinguish them from one another using different nomenclatures. Accordingly, the perforator flap based on a musculocutaneous perforator is named according to the name of the muscle perforated, the latissimus dorsi perforator flap, and the perforator flap based on a septocutaneous perforator, located between the serratus anterior and latissimus dorsi muscles, is named according to the name of the proximal vessel, the thoracodorsal perforator flap. In this series of 42 latissimus dorsi perforator flaps, flap size ranged from 5 x 3 cm to 20 x 15 cm, and two complications were observed: a marginal necrosis in an extremely large flap (26 x 12 cm) and a failure caused by infection. The thoracodorsal perforator flap was used in 14 cases, including two cases of chimeric composition. Flap size ranged from 4.5 x 3.5 to 18 x 15 cm, with no complications. In the two patterns of perforator flap that the author used, initial temporary flap congestion was observed in five latissimus dorsi perforator flap cases and two thoracodorsal perforator flap cases, when the flap was designed as a large flap or a less reliable perforator was selected. However, the congestion was not serious enough to cause flap necrosis. Several techniques, such as T anastomosis or inclusion of an additional perforator or a small portion of muscle, are recommended to prevent the initial flap congestion, especially when an unreliable perforator is inevitably used or when a flap larger than 20 cm long is required. A small portion of the muscle was included in six cases, when an unduly large or improperly long flap was planned. All of the flaps were successful and ranged from 22 x 7 to 15 x 28 cm, except for one case of distal flap necrosis in an extraordinarily large flap measuring 34 x 10 cm. Diverse selection of the perforator flap is one of the great advantages of the flank donor site, providing it with wider availability and more versatile composition for reconstruction or resurfacing.