br Discussion The ALT flap

Discussion The ALT flap was first described by Song et al in 1984. Clinically, it is versatile for reconstruction of the Solamargine and soft-tissue defects. It has several advantages, including reliability, a considerably long pedicle, and limited donor-site morbidity. Although the perforator variability of the ALT flap is a major concern, the dissection technique has been well established. Regarding reverse-flow ALT flap, the anatomical study performed by Pan et al revealed that regardless of whether the perforator of the flap originates from the descending branch or the transverse branch of the lateral circumflex femoral artery, the flap pedicle can be traced distally to connect with the lateral superior genicular artery or profunda femoral artery. Shieh et al presented type I and type III perforators derived from the descending branch of the lateral circumflex femoral artery, which are considerably easier to use for flap harvesting. They also proved that the arterial perfusion of reverse-flow ALT flap is adequate by measuring the blood pressure of the pedicle stumps. The mean proximal antegrade and retrograde blood pressures were 78.6 ± 13.0 mmHg and 45.8 ± 11.6 mmHg, respectively. The distal antegrade and retrograde blood pressures were 65.8 ± 11.6 mmHg and 61.1 ± 17.1 mmHg, respectively. In our series, the largest flap used measured 20 cm × 10 cm, with a mean of 140 cm2. By using the larger flap designs, we could easily reconstruct soft-tissue defects around the knee without tension. All of the reverse-flow ALT flaps reached the distal margin of the defects with adequate arterial perfusion. Zhou et al described a case of one ipsilateral knee and one contralateral lower leg reconstruction performed using pedicled reverse-flow ALT flap. The flap size was large (22 cm × 12 cm). Liu et al reported three cases in which reverse-flow ALT flap was used for knee defect reconstruction. The flap size in their study ranged from 6 cm × 3 cm to 26 cm × 8 cm. All flaps survived. Demirseren et al published several cases in which knee area reconstruction was conducted using a single flap. In their series, the mean flap size was small, with the largest flap measuring only 16 cm × 10 cm. In our series, venous congestion was observed in all four patients. In two patients, partial flap necrosis was observed, and secondary procedures were required. Venous congestion is a critical problem resulting from reverse-flow ALT flap that must be resolved. According to a literature review and our experience, larger flaps tend to have a higher incidence of venous congestion. In our series, the largest flap measured 20 cm × 10 cm, and the second largest flap was 22 cm × 8 cm. In both cases, almost one-third to two-thirds of the flap necrotized. In Demirseren et al\'s series, partial necrosis was observed in flaps measuring 10 cm × 14 cm and 6 cm × 13 cm. In the study by Liu et al, two flaps measuring 26 cm × 8 cm and 15 cm × 6 cm underwent marginal necrosis. On the basis of these data regarding flap viability, we suggest that flaps measuring >80 cm2 have a high incidence of partial or marginal necrosis, although there is no up-to-date quantitative scientific evidence supporting this inference. To resolve venous congestion, Demirseren et al suggested transferring flaps with a cuff of the vastus lateralis muscle included around the pedicle to protect the pedicle from shear forces and increase venous flow. Gravvanis and Britto mentioned that insufficient venous drainage could be caused by resistance of the venous valves, and a longer pedicle length could therefore increase the risk of venous congestion. They performed end-to-end anastomoses of the proximal stump of the descending branch of the lateral circumflex femoral vein to an adjacent superficial vein to resolve the congestion. The same method was reported by Komorowska-Timek et al, but Quaternary Period anastomosed the proximal ends of both the descending branches of the lateral circumflex femoral artery and vein to the anterior tibia artery and vein. This supercharge procedure maintained adequate arterial supply and venous drainage in large flaps (12 cm × 28 cm). In our study, we swung the proximal flap pedicle cranially. The major concomitant pedicle vein was then anastomosed to the great saphenous vein, substantially reducing venous congestion. Kim et al achieved the same success in resolving venous congestion by using great saphenous vein supercharge.