Island Rat Groin Flaps with Twisted Pedicles

Abstract

Clinical attempts are made to avoid rotating a flap and twisting the pedicle for fear of perfusion compromise. Torsion of an island rat groin flap pedicle is not a well-recognized experimental entity. The authors describe the results of island flap rotation with pedicle twisting in the rat groin flap model. Forty male Wistar rats were randomly divided into four groups of 10 animals each. In each group, bilateral groin flaps were elevated; one flap was sutured in place without rotation and the contralateral flap was subjected to 180, 270, 360, or 720 degrees of rotation. Blood flow within the flaps was assessed by laser Doppler flowmetry, and flap edema and necrosis were determined 10 days postoperatively. No differences were noted between control flaps and those subjected to 180 and 270 degrees of rotation. Although flaps subjected to 360 degrees of rotation demonstrated a large amount of postoperative edema and congestion of the subcutaneous tissue with some histologic changes, all flaps in this group survived. Measured flap weights at death were different from those of controls. All flaps subjected to 720 degrees of rotation underwent ischemic necrosis. Because of the differences between human skin architecture and rat skin architecture it cannot be concluded that similar results would be observed in any human skin flap. There might be three important points arising from this study of unknowingly twisted island groin flap pedicles in the rat model: (1) twisting of less than 360 degrees has no effect on flap survival; (2) twisting of 720 degrees is always associated with skin flap necrosis; (3) twisting of 360 degrees, although associated with some changes, does not cause skin flap necrosis.

Clinical Applications of Perforator-Based Propeller Flaps in Upper Limb Soft Tissue Reconstruction

“…Five previous experimental studies have studied the effect of pedicle twisting on flap survival. [22][23][24][25][26] Based on these studies and reports in the literature, perforator-based propeller flaps with a rotation up to 180°have shown to be viable and versatile. 2,3,8,9,21,27 In patients needing 180°of flap rotation, we attempt flap rotation in both a clockwise and counter-clockwise fashion.…”

The Effect of Twisting on Perforator Flap Viability

“…Our results also indicate that the tolerance of true perforator flap pedicles to torsion is much less than that of the axial pattern flaps or microvascular anastomoses. 22,23 In conclusion, when planning a true perforator flap, unless pedicle lengthening or flap delay is considered, twisting the pedicle more than 180°would seriously compromise especially arterial circulation of the flap and result in an increased rate of necrosis.…”

“…Although it is usually noted as an accident and an imperfection of the technique, sometimes it is mandated by the topology of the flap transfer and, according to its degree, compromises the circulation of the flap. 22,23 Previous studies on pedicle torsion indicate that torsion impedes and, when severe enough, occludes the blood flow by disrupting the smoothness and patency of the vessel wall, disturbing and slowing down the blood flow, causing endothelial damage and consequently promoting thrombosis. Veins are far more prone to the deleterious effects of torsion than arteries are.…”

“…Nevertheless, experimental trials demonstrate that it impedes the circulation in axial flaps and microvascular anastomoses, especially when it exceeds a limit of tolerance. 22,23 Our scan of the literature has yielded no studies concerning the effect of pedicle torsion on viability of the true perforator flaps, so we aimed to interpret the effect of pedicle torsion on true perforator flap viability in a rat model.…”

Free style perforator based propeller flaps: Simple solutions for upper extremity reconstruction!

“…Few previous experimental studies have studied the effect of pedicle twisting on flap survival. [1011121314]…”