A Novel Minimally Occlusive Microvascular Anastomosis Technique Using a Temporary Intraluminal Shunt: A Prospective Technique to Minimize Brain Ischemia Time during Superficial Temporal Artery-to-Middle Cerebral Artery Bypass

Abstract

To describe a new technique of suturing microvessels with persistent perfusion via a temporary intraluminal microshunt. Experiments were conducted in Wistar rats. Abdominal aorta grafts were explanted from donor rats. A soft silicon microcatheter was introduced into the lumen of this graft. The abdominal aorta of a recipient rat was prepared for end-to-side microvascular anastomosis. Acland clamps (S&T AG, Neuhausen, Switzerland) were applied, and a linear arteriotomy was made. One end of the graft-clad microcatheter was introduced into the lumen and occluded with a fenestrated Acland clamp. At a more distal part, a similar arteriotomy was performed, and the other end of the microcatheter was introduced into the lumen and clamped with a fenestrated Acland clip. This created a temporary shunt through the graft-clad microcatheter. Then, the graft was anastomosed to the arteriotomies at both ends, over the microcatheter, in an end-to-side manner. The microcatheter was explanted from the vessel lumen through an arteriotomy in the middle of the graft. The graft was clipped short to close this arteriotomy. The mean total occlusion time before perfusion was reestablished amounted to 3.7 minutes. This experiment was repeated in 12 animals (6 with and 6 without heparin) without technical complications. As controls, conventional anastomoses were made in 2 animals. Suturing microvessels mandates their occlusion during the period of anastomosis. Although ischemia is well tolerated by other tissue types, the brain is quite sensitive to even short windows of ischemia. Nonocclusive anastomotic techniques have been developed recently. These are confined to vessels with luminal diameters greater than 3 mm. We have evolved a novel technique that can be used with microvessels, as pertinent to superficial temporal artery-to-middle cerebral artery bypass. We have described a new technique for performing microvascular anastomoses over a temporary intraluminal microcatheter shunt.