Patency Of Interposition Vessel And Its Impact On Liver Functional Recovery And Graft Regeneration After Living Donor Liver Transplantation

Objective To evaluate the patency of interposition vessel after living donor liver transplantation (LDLT)with right-lobe graft(RL) without middle hepatic vein (MHV) using CT angiography (CTA)and determine the impact of patent interposition vessel on liver functional recovery and graft regeneration of anterior segment.Materials and methods Twenty-four patients underwent CTA in two weeks after LDLT using RL without MHV, the image of interposition vessel and MHV tributaries (V5,V8) and congestion of territory draining to the interposition vessel were analysed compared with Color-Doppler ulreasound (CDUS)findings. The reasons for different appearance of interposition vessel were explained according to the findings on CTA and CDUS. Advantages and disadvantages of both CTA and CDUS on detecting the patency of interposition vessel were evaluated. Anterior segment volume (ASV)and whole graft volume (GV) were estimated from CT scans.24 cases were divided into two groups according to the patency of interposition vessel determined by CTA:patent group and occluded group. The ASV/GV ratios were compared between the two groups. We also analyzed the liver enzymes (ALT and AST) between the two groups.Results 1,Among 24 cases,13 cases were patent in two weeks postoperatively Frequency of patency of interposition vessel of segmentⅤin typeⅠ(using straight cryopreserved vessel for reconstruction of single V5) was 82%; In typeⅢ(using Y-shaped cryopreserved vessel for reconstruction of V5 and V8), it was 70% in segmentⅤand 30% in segmentⅧ; There was no statistically significance of frequency of patency of interposition vessel in segmentⅤbetween typeⅠand typeⅢ. 2,CTA appearance:Opacification of interposition vessel and MHV tributaries(V5 orV8 or both) were seen in 13 cases. Among these 13 cases, distortion of interposition vessel were seen in 2 cases and anastomotic stenosis was found in 1 case,9 cases suffered from hepatic venous congestion of the territory draining to interposition vessel.11 occluded cases had different appearance on CTA:a.3 cases with congestion in the territory draining to interposition vessel showed no opacification of interposition vessel and MHV tributaries(V5 orV8 or both); b.2 cases with congestion of territory draining to interposition vessel had opacification of V5 or V8 but it did not extend to the margin of liver graft. There was no opacification of interposition vessel else; c.5 cases had patent interposition vessel of segmentⅤ.Among these cases,4 cases with congestion in segmentⅧshowed no opacification of interposition vessel of segmentⅧand V8,1 case with no congestion in segmentⅧshowed no opacification of interposition vessel of segmentⅧwhile Opacification of V8 was seen but it did not extend to the margin of liver graft; d. Opacification of V5,V8 and stem of interposition vessel was seen in 1 case with Y shaped interposition while there was no opacification of the branches of interposition vessel.3,The ASV/GV ratio in 2 week postoperatively among patent cases was 0.457±0.063versus 0.399±0.081 in the occluded cases (P=0.102).4,The levels of ALT in occluded cases at 1st,3rd,5th,7th and 14th day postoperatively were higher than the patent cases. albeit not significantly. The levels of AST in occluded cases at 1st,3rd and 14th postoperatively were higher than the patent cases, albeit not significantly. ALT decreased significantly at 5th day postoperatively in occluded cases and in patent cases it decreased at 3rd day postoperatively; Liver functional recovery was earlier in patent cases than occluded cases. AST decreased significantly at 3rd,5th, 7th,14th day postoperatively compared with the 1st day postoperatively both in patent cases and occluded cases.Conclusion:CTA is quite valuable to estimate the patency of interposition vessel for reconstruction of MHV tributaries and patent interposition vessel is benefical for liver functional recovery and liver regeneration.