To better describe and understand operative indications in surgery of the spleen, one could categorize the indications for splenectomy into eight general areas:
Hypersplenism – enlargement of the spleen by neoplastic disorders, hematopoietic disorders of the bone marrow, metabolic or storage disorders. These various disease processes result in enlargement of the spleen and amplify the normal function of elimination of circulating blood cells resulting in general pancytopenia. Erythrocytes and platelets are commonly affected. Hypersplenism also may cause symptoms of early satiety due to the splenic size.
Autoimmune disorders, erythrocyte disorders. Specific cytopenias are related either to antibodies targeting platelets, erythrocytes, or neutrophils. A second category of diseases relates to intrinsic structural changes within the erythrocyte that lead to a shortened red blood cell half-life with accelerated splenic clearance.
Injury to the spleen.
Vascular diseases. Splenic vein thrombosis and splenic artery aneurysm may require splenectomy for treatment.
Cysts and primary splenic tumors and abscesses. This would include treatment of simple cysts, echinococcal cysts, splenic abscess, and various benign neoplasms including hamartomas, hemangiomas, lymphangiomas, and rare malignant lesions.
Diagnostic procedures. This category of splenectomy occurs when the spleen is removed primarily to make a clinical diagnosis when none is available. A subcategory of this would be staging for Hodgkin’s disease, which has all but been eliminated based on alternative imaging techniques and current treatment regimens.
Iatrogenic splenectomy. Splenectomy that is performed due to an incidental injury to the spleen during surgery within the general abdominal cavity or specifically, the left upper quadrant, can be categorized as iatrogenic splenectomy. This category is likely underreported and may be considered a subcategory of trauma.
Incidental splenectomy. The spleen may be removed as part of a standard operation to remove the distal pancreas most commonly, and also for gastric cancers, left-sided renal cell carcinomas, adrenal cancers, and retroperitoneal sarcomas in the left upper quadrant. The spleen is removed in these instances due to direct tumor extension, vascular involvement, need for excision of splenic hilum lymph nodes.
When institutions analyze the most common reasons for splenectomy, trauma and incidental splenectomy account for the majority of the spleens removed. For elective splenectomy that is not incidental to removal of another organ or tumor, autoimmune disorders or other hereditary blood cell disease are common indication. Within this category, idiopathic thrombocytopenia purpura has the highest incidence for splenectomy. Each of these categories of disease will be discussed including the etiology and pathophysiology of the disorder, the specific indications for splenectomy, alternative treatments, and the results of splenectomy.