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SPLEEN SPLEEN

Lecture Xiv - Spleen

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  • SPLEEN

  • I. Anatomy- weight approximately 100-150 grams- located in the left upper and protected by the lower portion of the rib cage- its position is maintained by several ligamentsa. splenophrenicb. splenorenalc. splenocolicd. gastrosplenic short gastric a.

  • Spleen

  • - it is supplied by the splenic artery, which is a branch of the coeliac artery.

    - accessory spleens have been reported in 14% to 30%, ususally seen at the hilum, greater omentum, and ligaments of the spleen

  • Blood supply

  • - consists of the capsule and trabeculae which enclose the pulp.- 3 zones of the pulpa. White pulp lymph node; contains lymphocytes, macrophages, and plasma cells in a reticular network

    b. Red pulp consists of the cord and sinuses; contains the cellular elements of the blood

    c. Marginal zone poorly defined vascular space between pulps; contains sequestered foreign material and plasma as well as abnormal cellular elements

  • histology

  • II. Physiologic FunctionsA. Filtering splenic blood flow 350 ml/day1. removal of abnormal red blood cells approximately 20 ml of aged RBC are removed daily

    2.removal of abnormal WBC, plateletes

  • B. Immunologic Function1. opsonin production2. antibody synthesis (IgM)3. protection from infection

    C. Storage Function1. plateletes 1/3 are stored in the spleen 2. in splenomegaly, up to 80% of the plateletes may be stored in the spleen thrombocytopenia

  • splenomegally

  • splenomegally

  • III. DiagnosticA. Evaluation of size1. physical examinationa. not normally palpableb. felt in 2% of healthy adultsc. no significant dullness elicited by percussion over spleend. as organ enlarges, dullness is detected at the level of the 9th ICS in the left anterior axillary line

  • 2. CT/MRI depicts the spleen and defines abnormalities in size, shape and parenchymal pathology3. 99 Tc colloidB. Evaluation of function1. hypersplenism reduction in number of RBC, WBC, plateletes2. increase in cellular destruction results in compensatory rise in production in the bone marrow reticulocytosis

  • IV. PathologiesA. Rupture of the Spleen1. Etiology disruption of the spleens parenchyma, capsule, and blood supplya. spleen is the most commonly injured organ following blunt traumab. 2% splenic injury during surgery in the LUQ Gastric surgeryc. spontneous rupture hematologic disorders

  • CT scan of splenic and liver trauma

  • 2. Pathologya. splenic rupturei. intraperitoneal bleedii. 90% of blunt traumab. delayed rupturei. interval of days or weeks between injury and bleeding; 10%-15%

  • ii. Quiescent period (of Baudette) persists for less than 7 days up to 2 weeks

    iii. related to temporary tamponade of minor lacerations or slowly enlarging subcapsular hematoma

  • c. occult splenic rupture- pseudocyst of the spleen (1%)

    3. Clinical manifestationa. hypovolemia/tchycardiab. hypotensionc. localized (LUQ) or generalized abdominal paind. Kehrs sign pain at the tip of the left shoulder diaphragmatic irritatione. Balances sign ( mass or fixed dullness at the left upper quadrant

  • 4. diagnostic studiesa. CBC serial Hct determination leukocytosis

    b. x-ray of the abdomeni. fractured ribsii. elevated immobile diaphragmiii. enlarged splenic shadowiv. medial displacement of gastric shadow v. widening shadow between splenic flexure and preperitoneal fat

  • c. CT scand. angiography

    5. Treatment surgerya. children delayed surgical management

    b. adult - splenectomy

    c. splenectomized patients should receive pneumovax Haemophilus influenza vaccine and children should also be given oral penicillin daily until age 18

  • B. Hypersplenism1. Primary hyperslenisma. diagnosis by exclusion made after secondary hypersplenism has been excluded

    b. rare entity affecting women

    c. anyone or all formed elements may be affected

    d. enlarged spleen

    e. recurring fever and infection

    f. lymphoma and leukemia

    g. responds to splenectomy

    h. steroids do not improve condition

  • 2. Secondary hypersplenism caused by an identifiable underlying disease a. portal hypertensioni. splenic congestionii. most common cause of secondary hypersplenismiii. does not warrant splenectomy

  • b. splenic vein thrombosisi. massive splenomegalyii. thrombosis secondary to pancreatitis iii. associated with bleeding esophageal varicesiv. cured by splenectomy

  • CT and Angiogram of splenic vein thrombosis

  • c. other causesi. neoplasms leukemia, lymphoma, metastatic carcinoma

    ii. myelproliferative disorders

    iii. increase in RBC destruction thalassemia major

    iv. disorders in immune response infectious mononucleosis, Feltys syndrome (rheumatoid arthritis, splenomegally, neutropenia)

    v. diseases that infiltrate the spleen amyloidosis, sarcoidosis

  • Splenic tumor

  • V. SplenectomyA. Absolute Indications for Splenectomy1. splenic tumors echinoccocal cyst

    2. metastatic disease

    3. splenic abscess

    4.hereditary spherocytosis most common hemolytic anemia for which splenectomy is indicated

    5. bleeding esophageal varices

  • CT scan of splenic abscess

  • 6. chronic lymphocytic leukemia

    7. hairy cell leukemia

    8. Chronic myeloid leukemia more to ease the pain

    9. Sarcomas

    10 trauma

  • B. Relative indications for splenectomy1. congenital hemolytic anemias

    2. sickle cell anemia

    3. idiopathic autoimmune hemolytic anemia

    4. Thrombocytic thrombocytopenic purpura

  • 5. Feltys syndrome/Sarcoidosis (non-caseating granulomas)/Gauchers disease (lipid storage disease)/Niemann-Pick disease (abnormal storage of cholesterol and sphingomyelin)/Amyloidosis (abnormal extracellular storage of protein)

    6. Chronic rheumatoid arthritis

    7. granulocytopenia

    8. Hodgkins lymphoma

    9. Non-hodgekins lymphoma

    10. idiopathic thrombocytopenic purpura

  • VI. Splenectomy Outcomes- post-operative appearance of:a. siderocytes

    b. Howell-Jolly bodies

    c. leukocytosis

    d. increased platelete count

  • A. Complications1. left lower lobe atelectasis most common2. subphrenic hematoma3. subphrenic abscess can occur with placement of a drain4. pancreatitis trauma to the tail of the pancreas5. deep vein thrombosis low dose anticoagulants

  • B. Hematologic outcomes1. initiala. thrombocytopenia rise in platelete count within a few days

    b. chronic hemolytic anemias Hgb level above 10 g/dl

  • 2. long-terma. increase in platelete count rise to >150,000 more than 2 months after surgery

    b. 90-100% success for hereditary spherocytosis

  • C. Overwhelming Post-Splenectomy Infection (OPSI) 1. lifetime risk of severe infection

    2. incidence of 3.2% post-splenectomy

    3. loss of the spleens ability to filter and phagocytose bacteria and infected RBC

  • 4. most common sources of infectiona. Streptococcus pneumoniae most commonb. Heamophilus influenzae Bc. meninggococcusd. group A streptococci5. presents with pneumonia or meningitis

  • 6. risk factors for the development of OPSIa. indication for splenectomy - hematologic disorder vs traumab. overall immune statusc. interval from the date of surgery usually within 2 years

  • 7. preventiona.vaccine againsti. pneumoccocusii. H. influenzaeiii. meninggococcus- to be given within 7-14 days after splenectomy

  • b. booster dose for pneumococcal vaccine every 5-6 years

    c. annual influenza vaccined. daily dose of penicillin or amoxycillin for 2 years