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Prefabrication of fat tissue using a fascial flap based on the superficial inferior epigastric artery was studied in rats. First, the superficial inferior epigastric fascia was transposed over the inguinal fat pad. Two weeks later fascia and fat were elevated together as a prefabricated composite flap. At this stage, a pilot study was done in ten rats and perfusion of the flaps was tested with fluorescein. After confirming fluorescein staining of the prefabricated flaps, the study continued with experimental and control groups of rats. In the experimental group, prefabricated flaps were transposed to the subcostal area. In the control group, the pedicles of the flaps were severed, creating composite grafts. These grafts were transferred to the subcostal area in the same manner as in the experimental group. One week later the flaps were re-elevated and grafts were exposed. Fluorescein tests and Indian ink microangiography were carried out. In the experimental group, the flaps were stained, while grafts in the control group were not stained. Fat and fascia were found to be viable in the experimental group, while they were necrotic in the control group on histopathological examination. Based on these findings, we can conclude that the prefabrication of fat by vascular fascia is successful and may have application in plastic surgery.

Skin grafts regain their sensory innervation from the graft bed by the regeneration of nerve endings. Although some clinical studies report sensory recovery in skin grafts implanted on free muscle flaps, the mechanism of recovery is obscure. The purpose of this study was to investigate nerve regeneration in experimental skin grafts on free muscle flaps to elucidate this phenomenon. Thirty-eight male Sprague-Dawley rats, weighing 450-550 g were used in the study. The rat gracilis muscle flap was the free flap model transferred from one groin to the other using microvascular anastomoses. Full-thickness skin grafts harvested from the abdomen were used to cover the free muscle flaps after transfer. Four study groups were formed: Group I (n = 10): Free muscle flaps were transferred without any nerve anastomosis; Group II (n = 10): Free flaps transferred with the anastomosis of the muscle's motor nerve to a sensory nerve at the recipient site; Group III (n = 10): Free flaps transferred with the anastomosis of the muscle's motor nerve to a motor nerve at the recipient site; Group IV (n = 8): Skin grafts were placed directly on the fascia layer over the medial hindlimb muscles and served as controls. The specimens were harvested for histologic examination after 12 weeks. Histologic examination was performed to visualise regenerating nerve endings using HE, S100, Luxol Fast Blue and tyrosine hydroxylase staining. The specimens were categorically scored according to the staining pattern of neural structures around pilosebaceous units and statistical comparisons were performed by using paired t-test. Skin grafts in both Group II and Group III markedly received tyrosine hydroxylase at the base of their pilosebaceous units in many of the specimens and functional nerve twigs could also be traced from the muscle layer to the overlying skin graft. In contrast, the skin grafts in Group I did not show any nerve function in the central parts. The overall staining scores of Groups II, III and IV were significantly higher than Group I (P0.05; P0.001; P0.05, respectively). There was no statistically significant difference between other groups. No myelinated nerve fibres could be detected in any of the skin grafts with Luxol Fast Blue technique. It was concluded in the present study that skin grafts over reinnervated free muscle flaps can develop significantly better innervation than skin grafts over non-innervated muscle flaps. However, the activity in skin appendages indicating nerve regeneration may only imply a gross sensation and in the absence of any myelinated nerve fibres transmission of finer sensation cannot be expected in any of the study groups.

Microvascular reconstruction of a cranial defect in a 10-week-old infant, which is the youngest case in the literature, is reported. A latissimus dorsi free muscle flap was transferred to cover the defect and a split thickness skin graft was placed over the muscle flap. Despite the successful flap transfer in this case, microvascular reconstruction in an infant has its own risks and infants should be discussed as a separate entity apart from the other pediatric patients.