Splenectomy in Hematologic Disorders - Indications

Splenectomy in Hematologic Disorders Scott Nguyen Team 4 6/11/04 Indications       Idiopathic Thrombocytopenic Purpura (ITP) Hereditary Spherocytosis Chronic Autoimmune Hemolytic Anemia Non Hodgkins Lymphoma Hairy Cell Leukemia Chronic Lymphocytic Lymphoma / Chronic Myelogenous Lymphoma Chronic ITP      Autoimmune disorder of Adults Autoantibodies to platelet glycoproteins Antibodies act as opsonins and accelerate platelet clearance by phagocytic cells Also can bind to critical regions of the glycoproteins and impair function F > M 3:1, ages 20-40 Chronic ITP    Purpura, epistaxis, gingival bleeding Rarely GI, GU, intracranial hemorrhage Diagnosis – low platelet count, normal bone marrow, exclusion of other causes of thrombocytopenia Drugs  Viral infections  Autoimmune diseases  Lymphoproliferative diseases  ITP - Management   Assx disease w/ Plts > 50K – no tx needed If < 50K, bleeding – tx indicated  Glucocorticoids – Prednisone 1mg/kg 2/3 respond initially  25% completely respond   Acute severe bleeding Platelet transfusions  IVIG  Refractory ITP   Most respond to steroids, but >75% pts recurr after steroids tapered Splenectomy – removes source of antiplatelet Ig, removes source of phagocytic cells  Indications –    Plts < 10K after 6 wks med tx Plts < 30K, had insuffic response to med tx after 3mos Emergent splenectomy in cases of intracranial bleeding  Platelet transfusions should only be given after splenic artery ligated to prevent destruction Splenectomy for ITP     65-80% successful Usually platelet counts respond by 10 days Age < 60, good inititial response to steroids are favorable factors Laparoscopic splenectomy popular as spleen is usually small to normal sized Unsuccessful Splenectomy  Missed accessory spleen in 10%  Can localize w/ Radionuclide imaging   Long term steroid therapy Azathioprine or cyclophosphamide Hereditary Spherocytosis    Autosomal dominant deficiency of spectrin, red cell cytoskeletal protein - maintains osmotic stability Membrane abnormality results in red cells which are small, spherical, and rigid Spherocytes more susceptible to becoming trapped in spleen and destroyed Hereditary Spherocytosis Hereditary Spherocytosis   Clinical presentation – anemia, jaundice, cholelithiasis, splenomegaly Diagnosis – Family history of anemia  spherocytes on peripheral smear  Increased reticulocyte count  Increased osmotic fragility  Negative Coombs test  Treatment    Splenectomy decreases rate of hemolysis If diagnosed in childhood, splenectomy should wait until after 4yo to preserve immunologic function of spleen Cholecystectomy can be performed at same operation if documented gallstones Autoimmune Hemolytic Anemia  Conditions in which autoantibodies against pt’s own red cells are formed (IgG)  Abnormal destruction “marked” RBCs are prematurely destroyed by phagocytic cells  Complement activated on cell membranes – resulting in lysis  Causes      Idiopathic Lymphoproliferative diseases – CLL, NHL, Hodgkins disease Systemic Lupus Erythematosus or other Collagen Vascular diseases Postviral infections Drug induced (methyldopa, pcn, quinidine) Autoimmune hemolytic anemia      More in adults, F > M Moderate to severe anemia, high reticulocytes Spherocytosis on blood smears Splenomegaly Direct Coomb test positive Direct Coombs test Treatment   Make sure not drug related Steroids –  75% respond, 50% relapse   Splenectomy for those who fail steroid therapy Refractory cases – azathioprine and cyclophosphamide, other immunosuppressive drugs Hodgkins Lymphoma   Splenectomy routinely performed during staging laparotomy Confirms disease below the diaphragm (upstages II -> III)  Radiation tx -> Chemotx   Historically performed often Advances in imaging – CT, lymphangiography, PET – much improved nonoperative staging Hairy Cell Leukemia      2% adult leukemias Hairy Cells – neoplastic B lymphocytes w/ cell membrane ruffling Found in peripheral blood and bone marrow Usually in elderly men Symptoms d/t pancytopenia from hypersplenism and infiltration of bone marrow Hairy Cell Leukemia Hairy Cell Leukemia      Massive splenomegaly causing hypersplenism – rapidly and prematurely destroy all blood cells Symptomatic anemia Infectious complications from neutropenia Bleeding complications from thrombocytopenia Increased risk of second malignancy Treatment   Alpha interferon, purine analogs Splenectomy in refractory cases 40% pts get normalization of blood counts after  Usually response lasts > 10 yrs  50% pts require no further tx  Splenectomy    CML and CLL Pyruvate Kinase deficiency Hemoglobinopathies – sickle cell, thalassemia