Direct evidence of a connection between autotransplanted microvessel fragments and the host microvascular system.

There are no reports on the autologous transplantation and patency of microvessels in living tissue. We autotransplanted microvessel fragments (Mvf) labeled with DiI-Ac-LDL into the peritoneum and then observed the peritoneum for 7 days postoperatively with a conventional fluorescence or laser scanning confocal microscope. We illustrated a neomicrovascular network of transplanted Mvf labeled with DiI-Ac-LDL in the peritoneum with both a fluorescence and a laser scanning confocal microscope. Furthermore, we demonstrated not only the existence of erythrocytes in the lumina of transplanted DiI-Ac-LDL-labeled Mvf, but also the presence of India ink perfused through the superior mesenteric artery in the lumina of the labeled Mvf. This evidence directly suggests that transplanted Mvf can survive and proliferate to connect adjacent microvascular branches of the superior mesenteric artery in the very early phase of wound healing. Moreover, these findings imply that implantation of Mvf in the microvascular ischemic circulatory tissue might accelerate angiogenesis to reconstitute a new microvascular network connecting to the nearby host microvascular system, which ultimately improves microcirculation.