The author carried out an animal experiment using rabbits in order to observethe state of the circulation and vascularization of tubed pedicle flaps to serve as an aidfor judging the most suitable time for transplantation.
A pigment (Chinese ink) was directly introduced into the vessels, so as to observe the state as objectively as possible. This paper deals with the results obtained.
Using 84 rabbits, 2 tubes of 3 cm in breadth and 4 cm in length were preparedon the back of such animal.
On the 14th day after constructing the tubed flap, one end was detached and after another 14 days the other end was cut. At the completion of the flap and after the first and second detachment, a vasodilating agent was administered and the effect was comparedwith that of the control group. In other words ink-Ringer's solution was perfused into tubes after preparation, primary removal and secondary one and each tube was cut and observed after 2, 4, 6, 8, 10, 12, and 14 days.
In addition, in the tubes removed, the change of vessels especially at the part of implantation was pursued time-coursely.
The results obtained were as follows:
1. Distinct new-formation of vessels was already noticed after 48 hours at the implantation part of the primary removal. Dilatation and new-formation of vessels showed a decreasing tendency with a peak on the 6 th day both in the control and the K (+) groups. On the 12th day almost cured state was observed.
2. When the ends of a vessel on the tube side and a vessel of the recipient tissue were in touch, they connected without delay by opening the cut-ends.
3. When a vessel on the tube side and cut-end of vessel of the recipient tissue were closely situated but not touching a path was formed through the red cells and fibrinsbetween the two ends. This path formed later a tube with endothelial cells.
4. A newly formed vessel in the recipient tissue connected with a vessel of the tube.
5. It was found that a vasodilating agent worked effectively for circulation within the tube and the implantation part and for new formation of vessels; resulting in earlierhealing by about 2 days.
6. It was experimentally proved that the process of healing can be shortened by the use of a vasodilating agent at the final detachment of the flap.