A nomogram for prediction of early allograft dysfunction in living donor liver transplantation

HPi: A Novel Parameter to Predict Graft-related Outcome in Adult Living Donor Liver Transplant

BACKGROUND

Portal hyperperfusion is frequently associated with early allograft dysfunction (EAD). It is imperative to identify patients who would require portal inflow modulation. We aimed to identify factors associated with hyperperfusion-related graft injury and develop a predictive index for the same.

METHODS

Prospectively maintained database was queried to identify 135 adult living donor liver transplant recipients between September 2016 and July 2020. According to the calculated sample size, 96 patients were randomly selected for "test cohort". The remaining 39 patients made the "validation cohort." EAD was defined according to the A2ALL study. "Hyperperfusion index (HPi)," defined as posttransplant portal pressure gradient (ΔPpost)/graft-to-recipient splenic volume ratio (GRSVR), was devised on the basis of laws of flow dynamics and regression analysis.

RESULTS

Overall, 40 patients (29.6%) had EAD, six 90-d mortalities (4.4%) were attributable to EAD. In the test cohort, EAD patients (n = 29, 30.2%) had lower GRSVR (1.00 versus 2.22, P < 0.001), higher ΔPpost (14.8 versus 11.9, P = 0.004), and HPi (20.89 versus 8.67, P < 0.001). Multivariate analysis revealed GRSVR, ΔPpost, and HPi as significant factors to predict EAD. Receiver operating characteristic determined cutoff of HPi ≥9.97 could predict EAD with sensitivity of 90% and specificity of 73% (F-score = 0.712). HPi ≥16.25 predicted 90-d mortality with sensitivity of 100% and specificity of 78.9%. Patients with higher HPi had delayed graft-related recovery. Non-EAD patients had a higher 1-y (96% versus 79%) and 2-y (88% versus 79%) survival. The cutoff of HPi was validated well in the validation cohort (F-score = 0.645) (Hosmer-Lemeshow test, P = 0.89).

CONCLUSIONS

While predicted GRSVR may help identify at-risk patients preoperatively, intraoperatively calculated HPi is more accurate in identifying patients who would require portal inflow modulation. Achieving an HPi below target cutoff significantly decreases the risk of EAD even in low-GRSVR patients.

Uric Acid as a Predictor for Early Allograft Dysfunction after Living Donor Liver Transplantation: A Prospective Observational Study

Early allograft dysfunction (EAD) is a postoperative complication that may cause graft failure and mortality after liver transplantation. The objective of this study was to examine whether the preoperative serum uric acid (SUA) level may predict EAD. We performed a prospective observational study, including 61 donor/recipient pairs who underwent living donor liver transplantation (LDLT). In the univariate and multivariate analysis, SUA ≤4.4 mg/dL was related to a five-fold (odds ratio (OR): 5.16, 95% confidence interval (CI): 1.41–18.83; OR: 5.39, 95% CI: 1.29–22.49, respectively) increased risk for EAD. A lower preoperative SUA was related to a higher incidence of and risk for EAD. Our study provides a new predictor for evaluating EAD and may exert a protective effect against EAD development.