This lecture went through the anastamoses of liver transplantation, and started with the outflow vasculature, which takes place first in the operating theater. There are two techniques: the first is two end-to-end vena cava anastamoses- termed orthotopic transplantation. The drawback here is the requirement of full IVC clamping; this can cause renal injury. The second method is the piggyback method, where the donor suprahepatic vena cava is anastamosed to the confluence of the recipient hepatic veins. Outflow obstruction occurs 2-4% of the time, and kinking can be a problem if the length of the vessel is too redundant.
The portal vein anastamosis is done end-to-end. Kinking is also possible here. A PV thrombosis is rare (1-3%) and risk factors for this include severe portal hypertension or a pre-transplant PVT. In the later case, an intraoperative thrombectomy can be attempted if the thrombosis is fresh. If chronic, a bypass (iliac vein conduit) is constructed.
The hepatic artery is anastamosed next, with standard end-to-end fashion. There are all kinds of varied hepatic artery anatomy, so it cannot be assumed to come from the celiac axis in all patients. A frequent variant (noted in the radiology reports as a ‘replaced right hepatic artery’) is when the RHA comes from the superior mesenteric artery. Arterial conduits are often needed here too; the donor iliac artery can bring blood to the liver from the supraceliac aorta or infrarenal aorta, for example.
Complications of the HA anastamosis are important to know! Early thrombosis, in the first week post-transplant, causes hepatic necrosis. If thrombectomy is not possible, retransplantation (with status-1 listing) is required. Mortality rate is high. Late complications, like stenosis or thrombosis are sometimes well-tolerated by the patient. Risk factors for HA complications include smoking, arterial reconstruction, acute cellular rejection in the first week post-op, hypercoagulable state, and use of small vessels.
The biliary anastamosis can be end-to-end, or a roux-en-Y (particularly in patients with PSC or if they had a post-op bile leak). The roux anatomy is noted in the figure below. Remember, since the HA supplies the biliary tree, always check for HA patency whenever you detect a biliary complication!