"Left at right" liver transplantation with heterotopic implantation of left liver graft in the right subphrenic space: Reappraisal and technical concerns for decision making

Mechanisms of the ascites volume differences between patients receiving a left or right hemi-liver graft liver transplantation: From biofluidic analysis

BACKGROUND AND OBJECTIVE

Post-transplant refractory ascites (RA) is common in patients receiving living donor liver transplantation (LDLT) using a left hemi-liver graft than in those using a right hemi-liver graft. However, there is currently no clear mechanism explaining the effect of grafts on ascites drainage. The purpose of this study is to analyze the values of blood flow parameters in the portal vein under different grafts using computational fluid dynamics (CFD) to interpret the relationship between portal pressure values with ascites drainage.

METHODS

In this work, ascites drainage was counted in 30 patients who underwent left-sided liver transplantation and 26 patients who underwent right-sided liver transplantation. The portal vein flow models of the transplanted liver under different flow rates were established based on computed tomography (CT) images and finite element theory. Ascites drainage and blood flow parameters were qualitatively compared.

RESULTS

The results show that the ascites drained from patients who received LDLT with a left hemi-liver is three times as that with a right hemi-liver. The simulation results show that the coefficient of the pressure-velocity curve of the left-liver is 1.7 times of the right-liver under the same hydrodynamic conditions, which qualitatively agrees with the clinical data. Moreover, the streamline of the transplanted left liver shows more vortexes compared with the right liver, which is a major reason for the left liver's higher pressure value.

CONCLUSION

This clinical phenomenon is reproduced and comprehensively explained by the hemodynamic parameters of the portal vein. This work establishes the relationship between portal pressure values and floating water drainage, and offers a new way for physicians to predict postoperative risks intuitively.

Encouraging Split Liver Transplantation for Two Adult Recipients to Mitigate the High Incidence of Wait-list Mortality in The Setting of Extreme Shortage of Deceased Donors

Background: Organ demand for liver transplantation (LT) is constantly increasing. Split liver transplantation (SPLT) is an ideal option for increasing the number of available liver grafts for transplantation and ameliorating organ shortage to a certain degree. However, SPLT for two adult recipients is still not broadly applied. Methods: We retrospectively analyzed the outcomes of SPLT for adult recipients at a single center. All donor, recipient, and transplantation factors were thoroughly investigated to clarify factors affecting patient outcomes after LT. Results: One hundred consecutive adult SPLTs were performed during the study period. Early mortality and 1-year mortality occurred in 21 and 31 recipients, respectively. On multivariate analysis, graft weight (p = 0.036, odds ratio = 0.99, 95% confidence interval = 0.98–0.99) was the independent risk factor associated with early mortality; however, no factor was significantly related to 1-year mortality. On receiver operating characteristic curve analysis, a graft weight of 580 g was identified the cutoff for stratifying outcomes. Recipients transplanted with a graft weighing ≥580 g had significantly better outcome as compared with other recipients (p = 0.001). Moreover, SPLT remarkably provided a better survival benefit for recipients than those on the LT wait-list (p < 0.0001). Conclusions: Given the considerable incidence of wait-list mortality, SPLT for two adult recipients should be encouraged whenever possible to increase the donor pool and benefit patients awaiting LT. Nonetheless, caution should be taken with a smaller graft weight owing to the risk of early graft loss.