Splenectomy is not indicated in living donor liver transplantation.

Abstract

Potential conflict of interest: Nothing to report. TO THE EDITOR: We read with great interest the recent publication by Ito et al.1 published in the November 2016 issue of Liver Transplantation, which concludes that splenectomy is not indicated in living donor liver transplantation. The authors retrospectively reviewed 395 patients who underwent living donor liver transplantation (LDLT), including 169 (42.8%) patients with simultaneous splenectomy and 226 (57.2%) patients with spleen preservation. According to their findings, simultaneous splenectomy increased the incidence of reoperation for postoperative hemorrhage within the first week and did not increase the platelet count in the early postoperative period. Furthermore, the incidence of lethal infectious disease, intraoperative blood loss, and operation time were significantly higher in the splenectomy group. Last but not least, the incidence of small‐for‐size syndrome (SFSS) was comparable between groups. However, we cannot agree with their analysis for a number of reasons, which are analyzed in the following paragraphs. LDLT has become an effective and sufficient treatment for end‐stage liver disease. However, its wider application in the last decade has been limited due to the safety of the donor and graft size mismatching. The latter, also called SFSS, is associated with prolonged cholestasis and coagulopathy postoperatively, presence of severe ascites, and encephalopathy.2 The main mechanisms for the pathogenesis of SFSS are excessive portal flow and pressure through a small graft in combination with low arterial perfusion and outflow obstruction.2 Several approaches have been described in the literature in order to prevent excess graft inflow, such as shunt operation, splenic artery ligation/embolization, splenectomy, and hepatic vein outflow modification.2 According to Ito et al.,1 the indications for simultaneous splenectomy in their study were as follows: first, severe thrombocytopenia (platelet count < 30 × 109 L) in order to decrease the incidence of postoperative hemorrhage, and second, the improvement of the tolerance and adherence to pegylated interferon and ribavirin therapy for hepatitis C virus (HCV) by preventing postoperative thrombocytopenia among HCV‐positive recipients. The aforementioned indications for simultaneous splenectomy do not have any correlation with the prevention of SFSS. Splenectomy improves the outcome of a graft by reducing the portal pressure and flow and by increasing the vascular compliance of the graft.3 According to the literature,3 the main indications for simultaneous splenectomy during LDLT are portal venous pressure of ≥20 mm Hg after reperfusion4 and hypersplenism5 (platelet count < 7.5 × 104/μL and a leukocyte count <3500/μL). Gyoten et al.6 recently reported that in LDLT, the preoperative assessment of spleen volume to graft volume is a reliable predictor of portal vein hypertension after reperfusion of the transplanted liver, and for this reason, it can be used to specify the indication for splenectomy before reperfusion. Furthermore, this study has not mentioned any measurement of the portal venous pressure or portal venous flow intraoperatively, which means that the medical community cannot evaluate correctly the effect of splenectomy to the portal hyperperfusion. According to the literature,7 many studies have shown that splenectomy improves the vascular compliance of the graft and increases hepatic serotonin, which plays a significant role to the hepatic perfusion via vasodilatory effects. Hepatic serotonin improves microcirculation and promotes liver regeneration by stimulating the endothelial cells to release vascular endothelial growth factor, and it also protects the liver graft by increasing the microcirculation and accelerating liver regeneration. Last but not least, the authors described a significant increase of intraoperative blood loss and operation time in the splenectomy group. However, since 2005, because of the introduction of endostapling devices and tieless splenectomy via vessel‐sealing devices, the simultaneous splenectomy in LDLT is widely indicated with fewer complications, less operation time, and less blood loss.9 For the aforementioned reasons, we strongly believe that the title of this article is incorrect and misleading.