Influence of postoperative complications on long-term survival in liver transplant patients

BACKGROUND Liver transplant (LT) is a complex procedure with frequent postoperative complications. In other surgical procedures such as gastrectomy, esophagectomy or resection of liver metastases, these complications are associated with poorer long-term survival. It is possible this happens in LT but there are not enough data to establish this relationship. AIM To analyze the possible influence of postoperative complications on long-term survival and the ability of the comprehensive complication index (CCI) to predict this. METHODS Retrospective study in a tertiary-level university hospital. The 164 participants were all patients who received a LT from January 2012 to July 2019. The follow-up was done in the hospital until the end of the study or death. Comorbidity and risk after transplantation were calculated using the Charlson and balance of risk (BAR) scores, respectively. Postoperative complications were graded according to the Clavien-Dindo classification and the CCI. To assess the CCI cut-off value with greater prognostic accuracy a receiver operating characteristic (ROC) curve was built, with calculation of the area under the curve (AUC). Overall survival was estimated according to the Kaplan-Meier test and log-rank test. Groups were compared by the Mann-Whitney test. For the multivariable analysis the Cox regression was used. RESULTS The mean follow-up time of the cohort was 37.76 (SD = 24.5) mo. A ROC curve of CCI with 5-year survival was built. The AUC was 0.826 (0.730-0.922), P < 0.001. The cut-off was calculated by means of the Youden index with a result of 35.95. The sensitivity was 84.6% and the specificity 61.3%. Survival curves for comparison of patients with CCI score < 36 vs >= 36 were calculated. The estimated 5-year survival was 57.65 and 43.95 months, respectively (log-rank < 0.001). This suggests that patients with more severe complications exhibit worse long-term survival. Other cut-off values were analysed. Comparison between patients with CCI < 33.5 vs > 33.5 (33.5 = median CCI value) showed estimated 5-year survival was 57.4 and 45.71 months, respectively (log-rank < 0.0001). Dividing patients according to the mode CCI value (20.9) showed an estimated 5-year survival of 60 mo for a CCI below 20.9 vs 57 mo for a CCI above 20.9 (log-rank = 0.147). The univariate analysis did not show any association between individual complications and long-term survival. A multivariate analysis was carried out to analyse the possible influence of CCI, Charlson comorbidity index, BAR and hepatocellular carcinoma on survival. Only the CCI score showed significant influence on long-term survival. CONCLUSION A complicated postoperative period - well-defined by means of the CCI score - can influence not only short-term survival, but also long-term survival.