Biomedical subjects
Publications and source records attributed to F A Valauri.
Neovascularization of tissues into which a vascular pedicle has been implanted can result in the creation of a flap, or free flap, which is supported by those vessels as a neopedicle. This phenomenon allows the construction of customized prefabricated free flaps from tissue without restriction to naturally occurring vascular territories.
Experimental free muscle flaps were created by inducing transmural neovascularization. Free muscle flaps were developed in Sprague-Dawley rats through a three-stage microsurgical procedure. In the first stage, a muscle strip from the external oblique abdominus muscle was elevated and folded around the superficial epigastric vessels. At six days, the second stage was performed in which the muscle flap was detached from its origin and partially elevated, demonstrating that the muscle had developed an acquired terminal axial pedicle. At 12 days, the third stage was performed in which the muscle flap on its new pedicle was transplanted to a new site. Neovascular free flap survival was documented at intervals of three hours, one day, and six days post free transfer. Plastic casts of the muscle flap vascular tree were made to demonstrate neovascularization.
Microvascular thermic sleeve anastomosis performed with bipolar coagulation was investigated under experimental conditions. Patency rates of 100 percent for arteries (approximately 1.0 mm in external diameter) and 78 percent for veins (approximately 0.7 mm in external diameter) were achieved. The lumen contour was studied with plastic casts done at intervals of three hours, one day, three days, seven days, 15 days, and 30 days postoperative. Histopathologic studies were carried out to determine the changes caused by intussusception and heating spots.
Arterial end-in-end and end-to-end microanastomoses were done experimentally under natural tension and without tension. Intraluminal plastic casts were made at different postoperative time intervals, and the resulting stenosis at the site of anastomosis compared by lumen area measurements. Both anastomotic techniques revealed marked stenosis at the first hour postoperative, even when there was no tension applied to the vessels. The end-in-end technique (EIE) showed a luminal area decrease with increasing longitudinal tension. The end-to-end (ETE) did not, however, show any significant difference in stenosis, either in the nontension or the normal tension groups. No occluded anastomosis was found in either the EIE or ETE technique groups. This was remarkable, because it is during the first postoperative hour that residual luminal areas were as low as 23 percent in the successful EIE anastomoses.