THE FALLACY OF PRESUMED SUPERIORITY OF PROXIMALLY BASED VERSUS DISTALLY BASED FLAPS

As our knowledge of the origin of the cutaneous circulation becomes mo re precise, many preconceived notions continue to be abandoned. In thi s context, the general rule that distally based flaps are inherently i nferior to proximally based naps also should appropriately be challeng ed. To disprove this long-standing dictum, multiple abdominal flaps we re simultaneously elevated in 15 Sprague-Dawley rats that included or excluded all possible combinations of musculocutaneous or axial skin p erforators from each major source vessel (cranial or caudal epigastric s, superficial epigastric or lateral thoracic, respectively). These fl aps were sequenced randomly in each rat to have superior (proximal) or inferior (distal) pedicles such that at least five flaps of each subt ype were analyzed. Mean flap survival when the specific source vessel was retained uniformly was significantly greater than in all flaps whe re the source vessel had been excluded regardless of the orientation o f the flap pedicle. All naps with intact circulation had no significan t difference in mean flap survival. Similarly, when normal flap circul ation was excluded, no difference was observed in mean nap survival. A gain, both these observations were true irrespective of the location o f the nap base. Thus the major factor in determining flap viability wa s not whether its pedicle was proximally or distally based but rather the origin and quality of its intrinsic blood supply.