Experimental study of survival of pedicled perforator flap with flow-through and flow-end blood supply

BackgroundFlap viability after transfer depends on blood flow from the arterial blood supply below the fascia. This study evaluated survival of a pedicle flap with a perforator lateral branch and flow-through blood supply, compared with that of a flap with a flow-end blood supply and perforator terminal branch. MethodsForty Sprague-Dawley rats, 20 in each group, were assigned to transfer of a superficial epigastric artery pedicle island flap with a flow-through or flow-end configuration of blood supply. Laser Doppler imaging was used to evaluate flap perfusion 2h, 3days and 5days after surgery. The rats were killed on day5, and lead oxide-gelatine-enhanced flap angiography and histology with haematoxylin and eosin staining was performed. Dorsal midline tissue was excised for quantification of vascular endothelial growth factor by western blot assay. ResultsOn day5 after surgery, the flow-through group exhibited a significantly greater mean(s.d.) flap survival area (978(35) versus 808(102) per cent; P=0003), microvascular density (303(19) versus 207(41) per mm(2); P<0001) and perfusion (864(014) versus 595(014) perfusion units; P<0001) than the flow-end group. The flow-through group exhibited more angiosomes connected by dilated vascular anastomoses between the skin and subcutaneous fasciae. ConclusionThe flow-through blood supply improved pedicle perforator flap survival. Perforator flap failure is mainly the result of impaired blood supply, as a flow-end blood configuration is nourished only by the perforator terminal branch of the artery. This work showed that the flow-through blood supply nourished by the perforator lateral branch improved flap survival, with dilatation of collateral vascular anastomoses and increased neoangiogenesis. The use of a flow-through configuration improves perforator flap survival and could therefore minimize morbidity resulting from flap necrosis. Flow-through blood supply improved flap survival