Acute vascular thrombosis is a potentially fatal complication in solid organ transplantation. Pediatric liver transplantation is associated with a high incidence of hepatic artery thrombosis. Current methods of surveillance for vascular thrombosis are indirect and lack early detection. We have adopted the use of the 20-MHz implantable doppler probe to assess hepatic artery and portal vein blood flow in the immediate postoperative period after pediatric liver transplantation.

Four consecutive pediatric liver transplants were performed between January and July 2001. All four patients had the hepatic artery anastamoses constructed with the aid of an operating microscope. The implantable doppler probe was attached to the hepatic artery and portal vein distal to the anastamoses using topical fibrin sealant. During the postoperative period, the presence, quality, and character of the doppler signal from the hepatic artery and portal vein was assessed for 5-7 consecutive days.

In all four patients, the implantable doppler probe was successfully placed. Monitoring was easily learned and done by staff. One patient developed hepatic artery thrombosis which was accurately detected by the implantable doppler probe. The patient was re-explored, the problem addressed, and the graft salvaged. All patients had their probes removed without complication and were discharged.

The implantable doppler probe provides direct, real-time monitoring of hepatic artery and portal vein blood flow. Signal quality and character was easily assessed by physician and staff and reliably reflected intravascular flow. This allows for early detection and intervention of microvascular complications in pediatric liver transplantation.