Thank for posting on HCM! There are many causes for the increase in the number of blood platelets. splenectomy is also one of them. also known as reactive thrombocytosis. This group includes: Acute bleeding and blood loss. Allergic reaction. Cancer. Chronic kidney failure or other kidney disease. Infection. Iron deficiency anemia. Spleen removed. Inflammation, such as rheumatoid arthritis, celiac disease, connective tissue disorders, inflammatory bowel diseases. Major surgery. Pancreatitis. Injury.   Splenectomy was the main reason you thrombocythemia may last your lifetime. In order to avoid complications that may occur should you drink aspirin prophylaxis. Hope useful for you! wishing you good health!