Clincal Application Of The Saphenous Neurocutaneous Flaps Without Saphenous Nerve

[OBJECTIVE]To explore the feasibility of the simple saphenous neurocu- taneous flaps without the saphenous nerve,because it is a problem that the saphenous nerve of the donor site was sacrificed during elevation of the traditional saphenous neurovascular flaps, and patients were submitted to sensory disability, especially, the sensory of the donor site is more important than the recipient site.[METHODS]We summarized a lot of reports about the neurocutaneous flaps, and included that the blood supply of the simple neurocu- taneous flaps without the cutaneous nerve was not enough than the traditional neurovascular flaps with the cutaneous nerve, but the cutaneous nerve was not necessary to the blood supply of the flaps; and it was regarded as the venofasciocutaneous flap, the remnant cutaneous neurovascular plexus can also supply some blood to the venofasciocutaneous flap or the simple neurocu- taneous flaps without the cutaneous nerve, therefore, the flap can survive. Then ,we designed the simple saphenous neurocutaneous flaps without the saphenous nerve according to the above- mentioned theory.From February 2001 to November 2006, 9 cases, aged 17-55 years, of whom 4 with the anterior tibialis bone exposure, 3 with the calcaneal bone and tendo calcaneus exposure, 2 with the skin defects of dorsum of foot; of whom the fresh and old wound surfaces are 3 and 6 respectively; of whom the mechanism of vulnerate including: 6 by the traffic accident,2 by the leather belt and 1by weights; of whom the conditions of associated injury including: 3 with tibiofibula fracture, 1with rupture of Achilles tendon, 1 with fracture of metatarsal bone.The size of skin defect ranged from 3.5×5.5cm to 6.5×8.5cm, average was 5.5×7.5cm; the size of flap ranged from 4.0×6.0cm to7.0×9.5cm, average was 6.0×9.0m. In all cases, the date which the saphenous nerve was cut off and and anastomosed again was 2, the remnant saphenous nerves were dissociated completely; the date which the great saphenous vein was deligated was 5, the remnant great saphenous vein were not special handling.The time of the injury between operation ranged from 2h～58d.The Doppler blood vessel survey meter was used routinely to acquire site of the distal perforating branch of the arteria tibialis posterior or the arteria fibularis before operation.The operation is performed with the patient in a backlying position and under spinal or general anesthesia,with the aid of tourniquet control and loupe magnification. Firstly, proceed debridement and douched the wound repeatedly by dioxogen and normal saline, and then stopped bleedingby deligation and /or electric coagulation thoroughly after tourniquet released. Secondly, the flap was designed as follow: the swivel site above the internal malleolus'superior border for 4.5cm, the axis was determined by the line of the internal malleolus'anterior border between the femoral bone's endo-condyles, the length of pedicel was distance between the swivel site and the wound's distal lateral margin, the area of flap was larger 10% to 20% than the wound. Thirdly, the deep fascia layer is dissected from proximal end to expose the the saphenous nerve and make sure the nerve in the middle of the flap; then elevated the flap by the adjusted skin making, the epineurium of saphenous nerve were dissected and remained the nerve carefully. Sometimes, we cut off and pull out the nerve stem near to the proximal end when the chain-style blood vessel bestrided the nerve stem, and anastomosed the nerve again. The pedicle with the deep fascia around the nerve about 1.5-2.0cm respectively was taken through a wave skin incision, spared the saphenous nerve to the pedicle sequentially and protected the nutrient vessels and branch. Then, we observed the engorgement of the great saphenous vein, and if the great saphenous vein engorged obviously, we deligated it from pedicle carefully to preserve the nutrient vessels, or the great saphenous vein was not special handling. The elevated flap was rotated 180 degrees and transferred to the defect either through a skin tunnel or by a direct incision on the skin bridge, and closed the incision by interrupted suture after adjustting the flap to the suitable site. Fourthly, we closed the incision of the pedicle by interrupted suture directly, the saphenous nerve was placed on the healthy tissue, and the wound of the donor site was repaired by the full-thickness skin graft or the split-thickness skin graft from femoribus internus and closed the incision directly.Finally, the patient'broken leg was fixed by plaster slab and accepted drug treatment to infection prevention,antispasmodism and anticoagulation after operation routinely.[RESULTS]Of the 9 patients, 6 of them had presented different engorge- ment and violet, of whom the great saphenous vein was not special handling and deligated were 4 and 2 respectively, the remnant blood circulation were fine; finally, 2 developed distal margin epidermal necrosis and proced dermatoplasty to make the wound heal, the remains achieved survival fully. All 32 cases were followed up for 3 to 41 months, average was 21 months.The appearance of 3 flaps were fat and clumsy and formalized, the remains were not formalized but the colour,texture and appearance were satisfactory. About the sensation of the medialis cnemis and foot, 7 of them were not sensory disability, 2 of them recovered the sensation of the medialis foot 9 months and 11 months after operation respectively. The sensation of the medialis cnemis of 6 patients reached to S2+, the remains were S2. 8 patients went back the old job, only 1 patient unemployed resulting from ununited fracture. [CONCLUSION](1) The simple saphenous neurocutaneous flaps without the saphenous nerve is feasibility:The blood supply of the simple neurocutaneous flaps without the cutaneous nerve was not enough than the traditional neurovascular flaps with the cutaneous nerve, but it was regarded as the venofasciocutaneous flap, its survival depended on the superficial vein vascular net and fascia vascular net, the remnant cutaneous neurovascular plexus can also supply some blood to the flap, therefore, the flap can survive; the route of its venous return were the accompanying veins of perforating arteries and the communicating branches of the deep and superficial vein stem.(2) The sensory of the more important donor site was protected in the flap: The blood supply of the saphenous nerve which their epineurium were dissected depended on the arteria saphena at proximal end and the perforating arteries at distal end respectively, the chain-style blood vessel net in the nerve stem can provided the circulation route; the basal surface'serofluid can provide nutrition to nerve early, and the new anastomosis between newborned small vessels and neurovascular net could ensured the nerve's nutrition at later period. Finally, the sensory reestablishment of the free skin graft or skin depended on newborned nerve shoot.(3) Indication: The distally bassed flap is adapted to the loss of soft tissue at the level of the distal 1/3 of the leg,ankle and heel and forefoot, but the area of flap was confined.