The interrelationship between portal and arterial blood flow after adult living donor liver transplantation

Background. When adults are transplanted with segmental grafts, disparity b etween the size of the graft and the native organ is almost universal. Thes e grafts presumably still receive all of the native portal inflow despite a reduced vascular bed and dramatically elevated blood flow may result. The hemodynamic changes after segmental transplantation in adults have not yet been studied and their clinical significance is unknown. Methods. Portal venous and hepatic arterial blood now were measured intraop eratively in right lobe liver donors and recipients with electromagnetic no w probes. Postoperative evolution was monitored in recipients with ultrason ography. Results. Portal flow to the right lobe ranged from 601 to 1102 ml/min befor e resection and from 1257 to 2362 ml/min after transplantation. There was a statistically significant linear correlation between the change in portal flow and graft to recipient body weight ratio. Arterial blood flow ranged f rom 213 to 460 ml/min before resection and from 60 to 300 ml/min after tran splantation. Preoperative portal peak systolic velocity was uniformly aroun d 10 cm/sec. Values on postoperative day 1 were increased to 30 cm/sec in r ecipients of cadaveric organs, to 50 cm/sec in recipients of organs with gr aft to recipient body weight ratios of more than 1.2%, and to 115 cm/sec in recipients of organs with ratios less than 0.9%. A decreasing tendency was universally observed, Arterial systolic velocity was inversely related to portal systolic velocity. Neither graft dysfunction nor vascular complicati ons occurred. Conclusions. The hemodynamic pattern after right lobe transplantation is pr edictable and intraoperative measurements and ultrasonography are useful fo r monitoring, The size of the graft influences the magnitude of the hemodyn amic changes.