Portocaval shunt and its Implications for Liver Transplantation: An Integrative Literature Review

Abstract

Introduction: Portal vein clamping can generate splanchnic venous congestion and increase portal hypertension, causing release of inflammatory mediators in liver transplantation. The venous bypass technique was developed at the beginning to avoid congestion. In 1968, the piggyback technique was described, and in 1993 and 1995, the temporary portocaval shunt (TPCS) was described as an alternative to preserve the flow of the vena cava and the intraoperative portal system. With the expansion of the number of living transplants, an adaptation of the anastomosis, or temporary hemi portocaval shunt (THPCS) was developed. Objective:This review aimed to analyze the literature found in the TPCS and THPCS databases in adult liver transplantation. Methods: Integrative review carried out through searches in PubMed, Online Scientific Electronic Library (SciELO) and Literatura Latino-Americana e do Caribe em Ciências da Saúde (Lilacs) databases, with 15 articles published in the last 12 years (2010-2021) being selected, after applying criteria defined by the authors and including three works for historical reference. Results: The increase in surgery time does not seem to be a significant disadvantage that justifies contraindication to the use of portocaval anastomosis during the procedure. In transplantation, there is an indication that the TPCS improves hemodynamic stability, with reduced infusion of packed red blood cells and platelets. Data on postoperative levels of aminotransferase, aspartate aminotransferase, and international normalized index were conflicting, with improvement in renal function as assessed by creatinine measurement. The studies demonstrate a relationship between TPCS and a decrease in hospital stay. It was not possible to reach a conclusion regarding the impacts on survival after transplantation. THPCS appears to be effective in decreasing portal flow, serving its purpose of preventing hyperflow, however it does not appear to be an absolute guarantee of preventing complications. The biggest perceived limitation was the heterogeneity of the studies included in this review. Conclusion: The developed studies point to benefits in hemodynamic stability and postoperative renal function and shorter hospital stay. It was not possible to conclude about the impact of the technique on liver injury, overall survival or graft survival, due to divergences in the literature.