J Korean Soc Plast Reconstr Surg.
1998 Jul;25(5):755-768.
The effects of bed isolation with silicone sheet on the survival of prefabricated flaps
Abstract
- In making prefabricated flaps, a bed isolation has been suggested by many previous studies as an adjunctive procedure to incite revascularization of the flap from vascular carrier by inducing a ischemic state as like as a delay procedure and blocking the neovascularization from the bed. To decide whether the bed should be isolated, or not during the flap prefabrication, we need to know it actually affects the survival of prefabricated skin flap. If it does, we should also know how and how far. The purpose of this study was to demonstrate the effects of bed isolation and to investigate whether the bed isolation is necessary during flap prefabrication. Prefabrication of an 3x4 cm sized abdominal donor site was performed as like pocket in both sides, using the transposition of both saphenous pedicles with gracilis fascia to the subpanniculus layer in 30 Sprague-Dawley rats. All flaps in the left side were isolated with silicone sheet from the bed of rectus fascia(experimental side) and all in the right were not(control side). Above sized flaps were elevated as an island and reposed immediately two weeks after prefabrication in group I(n=10), three weeks after in group II(n=10), and four weeks after in group III(n=10). Flap survival was assessed at day 3 after the flap elevation and reposition. The mean proportion of the survival area was 79.3% in the left and 88.7% in the right side in group 1. In the group II,68.7% in the left and 69.9% in the right, and 64.1% in the left side and 79.3% in the right in group III. Grossly, this results showed that the survival area of th prefabricated flap with bed isolation was less than that of non-isolated flap, which was different from the results of previous similar studies. But in comparing to the survival area of the prefabricated flaps for each time interval, there was no significant statistical difference between the control side and the experimental side(p>0.05). And the time interval between the flap prefabrication and the elevation did not affect the survival rate in the same side for each prefabricated method(p>0.05). With further study of histologic examination, the inflammatory reaction and the development of the granulation tissue were more plentiful in the experimental sides due to the foreign body reaction by silicone sheet insertion, and numerous small sized vessels were present around the implanted pedicles. In conclusion, during flap prefabrication, isolation of the bed with a silicone sheet did not improve the survival of prefabricated skin flaps. And may be cause of the increased survival area in the isolated groups was thought to be secondary effects of the inflammatory reaction rather than neovascularization induced by ischemic state.