The enlarged spleen – a blood bank

Abstract

Splenomegaly may be the result of several diseases such as myeloproliferative disorders, portal hypertension etc. Sometimes the splenic size may assume massive proportions. A massive splenomegaly may lead to symptoms or changes in laboratory parameters over and above the original disease state. The predominant symptoms include pain due to the splenic infarcts, dragging sensation due to the sheer size, early satiety etc. It has been known for several decades that a large spleen is a massive pool of sequestered blood cells. It can be holding 30–90% of all platelets and 40% of all erythrocytes. The bone marrow is typically hypercellular to compensate for this sequestration. Splenectomy entails removal of the whole spleen along with the sequestered blood cells in the spleen. This seems like a terrible waste of the sequestered blood components. If one was able to harvest these components the potential benefits could include a rise in the hematocrit, possibly avoidance of blood transfusion, immediate rise in platelet count, with implications for hemostasis and a rise in leucocyte count. The potential secondary benefits may include easier handling of a smaller spleen, reduced blood loss and lesser operation time. While it is quite common practice to ligate the splenic artery first, during splenectomy for a massive splenomegaly, the objective benefits of this step have been studied by few. This step of the surgical procedure is commonly performed by surgeons to reduce the problems of handling a massive spleen and, possibly, reduce blood loss during peri-splenic dissection, particularly in patients with portal hypertension. The ‘auto-transfusion’ of sequestered components is but a side-effect of this step. One concern of such an auto-transfusion is the quality of blood cells being released into the blood stream. Other potential concerns are the risks of dissecting the large tortuous splenic artery, especially in patients with portal hypertension, in the face of unquantified benefits. The study by Madhavan et al in this issue of the journal studied the objective benefit of early ligation of the splenic artery during splenectomy for portal hypertension.They studied 30 patients with portal hypertension (NCPF 20, EHPVO 9, Cirrhosis 1) who underwent splenectomy and proximal spleno-renal shunt in their unit. They found that there is significant increase in the RBC and platelet counts, though there was no statistically significant increase in the total leucocyte count, differential leucocyte count and hemoglobin. Even though the study suffers from several methodologic flaws it does bring into focus the auto-transfusion benefits of early ligation of the splenic artery during splenectomy. However the study does not report the percentage changes in the cell counts and only the mean values have been used for analysis instead of paired analysis. Gazula et al had earlier studied a similar population and reported a significant increase in the hemoglobin, hematocrit, leucocyte, platelet and RBC counts after early ligation of the splenic artery. They had restricted intravenous fluid administration after splenic artery ligation and thus found that benefits extended to increased hemoglobin, hematocrit and leucocyte count also. Both the studies excluded patients requiring intravenous fluids or blood transfusion and did not include a control population. While this may have removed the confounding