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.

Morbidity analysis of left hepatic trisectionectomy for hepatobiliary disease and live donor

BACKGROUND

Despite remarkable advances in surgical techniques and perioperative management, left hepatic trisectionectomy (LHT) remains a challenging procedure with a somewhat high postoperative morbidity rate compared with less-extensive resections. This study aimed to analyze the short- and long-term outcomes of LHT and identify factors associated with the postoperative morbidity of this technically demanding surgical procedure.

METHODS

The medical records of 53 patients who underwent LHT between June 2005 and October 2019 at a single institution were retrospectively reviewed. The independent prognostic factor of postoperative morbidity was analyzed using the logistic regression model.

RESULTS

Hepatocellular carcinoma was the most common indication for surgery (n = 21), followed by hilar cholangiocarcinoma (n = 14), intrahepatic cholangiocarcinoma (n = 10), and other pathologies (including colorectal liver metastasis, hepatolithiasis, gallbladder cancer, living donor, hemangioma, and multilocular biliary cyst; n = 8). The rates of postoperative morbidities of Clavien-Dindo grade 3 or higher and 90-day mortality were 39.6% and 1.9%, respectively. The 1-, 3-, and 5-year overall survival rates were 81.1%, 61.4%, and 44.6%, respectively. Multivariate analysis revealed that preoperative jaundice [hazard ratio (HR) = 6.15, 95% confidence interval (CI): 1.57-24.17, P = 0.009] and operative time > 420 min (HR = 4.66, 95% CI: 1.27-17.17, P = 0.021) were independent predictors of postoperative morbidity.

CONCLUSIONS

The in-hospital mortality of LHT surgery can be minimalized by a reliable preoperative evaluation of liver function and selection of the dominant anatomic features of right posterior sector, active and appropriate preoperative management for obstructive cholangitis and compensatory hypertrophy of the future remnant posterior sector, and the experience of the surgeon.

Current status of liver transplantation in Asia

In spite of early adoption of the brain death legislation, and all efforts at promoting deceased donation, various social, economic and cultural factors have acted as road blocks to the furthering of deceased donor liver transplantation (DDLT) in most Asian societies. On the other hand, Asian liver transplant centers have been the pioneers, innovators, and technical advancement catalysts for the world to follow, especially with regards to living donor liver transplantation (LDLT). With some high volume centers performing more than 200 LDLTs a year with good outcomes in the donor and recipient, techniques to expand the living donor pool have also been adopted like ABO-incompatible, paired exchange and dual lobe living donor liver transplants. Although large multicenter, and registry data as regards safety and outcomes of minimally invasive donor hepatectomy are awaited, expert centers have pioneered, and now regularly perform purely laparoscopic and robotic living donor hepatectomies, especially in Korea.