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[Study on animal model of perforator sural neurocutaneous flap].

OBJECTIVE
To establish the experimental animal model of perforator sural neurocutaneous flap for laying a foundation of further study on its physiology and haemodynamics.


METHODS
Thirty-five New Zealand rabbits were divided into four groups, weighing 2.5-3.0 kg and being male or female. In group A (n=5), vivisection was performed to observe the starting point and arrangement of sural nerve, its concomitant vessels, posterior tibial artery and perforating vessel. In groups B and C (n=5), red latex and gelatin-lead oxide were injected into the concomitant arteries of sural nerve and the posterior tibial arteries respectively to observe their arrangement, the diameter and anastomosis. In group D, forty neurocutaneous flaps based on single perforator were elevated in the twenty rabbits with a size of 7 cm x 1 cm and a pedicle of 0.5 cm. The colour and condition of flaps were observed.


RESULTS
The sural nerve originated from posterior tibial nerve, passed through the lateral head of the gastrocnemius at site of the popliteal fossa, descended obliquely to exterior, entered in the deep fascia at about (5.42 +/- 0.15) cm above lateral malleolus, and descended vertically to lateral malleolus. Its concomitant artery originated from deep femoral artery with an initial diameter of (0.73 +/- 0.11) mm and extended to the lateral malleolus along the sural nerve. A perforating branch of posterior tibial artery at the position of the calcaneus originated from the midpoint of the line connecting between the medial malleolus and the calcaneus with an initial diameter of (0.45 +/- 0.01) mm. The perforating branch traversed the calcaneus to the region of the lateral malleolus, and anastomosed to the concomitant artery of the sural nerve, forming a vascular plexus around the sural nerve. In group D, two cases were excluded due to infection. The survival rate was 78.0% +/- 1.5% in other 38 flaps 10 days after operation.


CONCLUSION
The perforator based sural neurocutaneous flap in rabbit is a good experimental model, which has stable anamatic features and reliable blood distribution.