Experimental Research In Rabbits And Clinical Application Of Reverse Island Flaps In Fasciocutaueous-pedicled Form

Objective:To explore the influence of the fasciocutaneous pedicle to the survival of the reverse island flap and the role of the fasciocutaneous pedicle to the venous return of the flap.To summarize the clinical experience of the reverse posterior tibial vessels island flap and posterior interosseous vessels island flap in fasciocutaneous-pedicle form.Method:In the preliminary experiment,9New Zealand rabbits were performed anatomy,injection of methylene blue, barium sulfate-latex injection, and retrograde island flap based on saphenous vessels with various sizes and different pedicles. According to the defferent pedicles,15New Zealand rabbits were devided into five groups:group A(retrograde island flap without fasciocutaneous pedicle); group B(retrograde island flap with0.5-cm-wide fasciocutaneous pedicle); group C (retrograde island flap with1.5-cm-wide fasciocutaneous pedicle); group D (retrograde island flap with1.5-cm-wide fasciocutaneous pedicle but without saphenous vein). All the flaps were designed with the demension of7.0cm×3.0cm, the pedicle length of3.0cm, and the pivot point locating at2.0cm bove the medial malleolous. The flaps in group E was elevated and sutured in situ. At7to10days postoperatively, all the flaps’survival rates were recorded. All the data was analyzed by SPSS17.0. The arterial supply and venous drainage of various flaps were observed and recorded when the flaps were executed injection of methylene blue, barium sulfate-latex, and meglumini diatrizoici. We retrospectively reviewed the data of both57retrograde island flap based on dorsal interosseous vessels and fasciocutaneous tissues and40retrograde island flap based on posterior tibial vessels and fasciocutaneous tissues from Department of Orthopaedics, Second Xiangya Hospital, Central South University, Changsha, China between January2002and January2013, and summarized the clinical eaperiences of both flaps.Results:The saphenous vessels is similar to the posterior tibial vessels in human, and retrograde island flap based on the saphenous vessels in rabbit is a good experimental model which may serve as a reproducible and reliable flap model for additional studies in this field. In the preliminary experiment, all the flaps based on the saphenous vessels and fasciocutaneous pedicle of1.5cm in width survived completely.Thirty retrograde island flaps with various pedicles were devided into five groups (6flaps in each group). In group A,3flaps survived uneventfully, the other3flaps developed partial necrosis, and the average survival rate was85.57%. In group B,4flaps survived uneventfully, the other2flaps developed partial necrosis, and the average survival rate was88.10%. In group C, all the flaps survived uneventfully and no flap developed partial necrosis. In group D,4flaps survived uneventfully, one flap developed partial necrosis, complete necrosis occurred in the other flap, and the average survival rate was73.83%. In group E, all the flaps developed complete necrosis. Comparison between every two groups was performed using Mann-Whitney U test, and there was no significant difference in the survival rate. Among group A, B and C, the survival rate increasing along with the increased width of the fasciocutaneous pedicle. Through the injection of methylene blue, and radiograph and microanatomy of specimens which were injected with barium sulfate-latex,"puzzle" anastomosis and anastomosis between perforator veins could be observed on the fasciocutaneous pedicle. However, the injection of meglumini diatrizoici showed that the blood in veins was mainly drained by the perforaor veins from the main vessel, and no blood was seen in the fasciocutaneous pedicle. At the time of review, follow-up of all the patients was carried out, there was no complete necrosis flap in this series. Of57retrograde island flap based on dorsal interosseous vessels and fasciocutaneous tissues,52(91.2%) flaps survived uneventfully and distal partial necrosis occurred in5(8.8%) flaps. Of40retrograde island flap based on posterior tibial vessels and fasciocutaneous tissues,38(95.0%) flaps survived uneventfully, distal partial necrosis occurred in5(5.0%) flaps, and6flaps with the top edge propelling the popliteal fossa horizontal grain survived completely.Conclusion:(1) The retrograde island flap based on the saphenous vessels and fasciocutaneous tissues in rabbit is a good experimental model which may serve as a reproducible and reliable flap model for additional studies in this field.(2) The veneous blood in the retrograde island flap based on the saphenous vessels and fasciocutaneous tissues in rabbits were drained by the main vein through going against the venous valve. The fasciocutaneous pedicle could play partial role in drainage of the veneous blood in the flap, by means of anastomosis between perforator veins.(3) In the rabbits, the fasciocutaneous tissue along with the main vessel can improved the reliability of the retrograde island flap.(4) The attached fasciocutaneous pedicle can facilitate harvesting the retrograde dorsal interosseous vessels flap and improve the viability of the flap.(5) The retrograde island flap based on posterior tibial vessels and fasciocutaneous tissues is reliable.