Spleen

Red and white pulp. (With permission from Mulholland MW, Lillemoe KD, Doherty GM, Maier RV, Upchurch GR, eds. Greenfield’s Surgery. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2005.)

Red Pulp

Comprises 85% of the spleen

Cell types: Mononuclear phagocytes

Functions

Clears nucleated remnants from immature RBCs

Clears dead or damaged RBCs

Without spleen—have Howell-Jolly bodies (nuclear remnants)

White Pulp

Comprises 15% of the spleen

Cell types: Lymphoid, mostly B cells

Functions

Clears bacteria without preexisting antibodies

Clears poorly opsonized bacteria

Clears foreign particles

Clears cellular debris

What are the two types of arterial supply of the spleen?

Magistral and distributed (most common).

Arterial supply of the spleen. (With permission from Mulholland MW, Lillemoe KD, Doherty GM, Maier RV, Upchurch GR, eds. Greenfield’s Surgery. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2005.)

Arterial Supply of the Spleen

Magistral: A single arterial pedicle

Distributed: Multiple branches enter the spleen arising from main trunks 2 to 3 cm from the hilum

A 32-year-old man who underwent a splenectomy does not have any Howell-Jolly bodies on a peripheral smear. What does this finding indicate?

The lack of Howell-Jolly bodies suggests that the patient may have unresected accessory splenic tissue or splenosis. Splenosis refers to the auto transplantation of splenic fragments.

Products Removed by the Spleen

Howell-Jolly bodies (nuclear remnants)

Pappenheimer bodies (iron granules)

Heinz bodies (denatured hemoglobin)

Target cells (deformed cells)

Stippling (inclusions)

Acanthocytes (spurred cells)

After splenectomy, a patient has persistent thrombocytopenia. What should you look for?

Perform imaging evaluation to see if the patient has an accessory spleen.

During a splenectomy, the tail of the pancreas was inadvertently resected with the specimen. What is the next step?

Place a surgical drain or multiple drains at the cut end of the pancreas (the pancreatic stump).

A 55-year-old male presents with a mass in the tail of the pancreas on CT scan that appears to be arising from the spleen. What is another test to evaluate the possibility an accessory spleen?

A sulfur colloid (“liver-spleen”) scan can help determine if the mass has the same consistency of the spleen.

What is the difference between splenomegaly and hypersplenism?

Splenomegaly is an enlarged spleen. Hypersplenism refers to any combination of neutropenia, anemia, or thrombocytopenia due to splenic sequestration.

A 48-year-old man with a history of cirrhosis presents with severe portal hypertension and a massive spleen. What is the best management of the splenomegaly?

Do NOT perform a splenectomy for portal-venous hypertension. Any operation in this setting carries an extremely high operative mortality. The best management is treatment of the underlying portal hypertension.

The most accepted contraindication to a splenectomy is portal hypertension.

A 59-year-old man with a history of IV drug abuse presents with a partial splenic infarction. What volume of normal splenic volume is required for full function?

Approximately 30% to 50% of the spleen’s mass can achieve most of the function of the entire spleen.

Splenic Infarction

Rarely requires surgery

Most resolve spontaneously

Pain may persist for weeks

There is no correlation between spleen infarctions and abscess formation

A 34-year-old man has a splenectomy performed for trauma. What is the most common trend in platelet count postoperatively?

The spleen normally stores approximately one-third of the body’s platelets, resulting in decreased sequestration and increased circulating platelets following a splenectomy.

Post-splenectomy Changes

RBC increases

WBC increases

Platelet count increases

Decreased antibody response to antigens (the opsonins, tuftsin, and properdin are produced in the spleen)

Against which organisms should one be vaccinated prior to splenectomy?

Encapsulated organisms: Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis.

When should the splenectomy patient be immunized?

At least 2 weeks prior to surgery is ideal so that fevers associated with the vaccine are not confused with postoperative sepsis. If the surgery is unplanned, vaccination should be delayed until the patient has regained immunocompetence. Vaccination is given prior to discharge for a poorly compliant patient.

A 48-year-old man presents with refractory bleeding varices and a long-standing history of pancreatitis. What intervention may be indicated?

Bleeding gastric varices in the setting of splenic vein thrombosis are effectively treated with splenectomy.

Splenic Vein Thrombosis

Associated with pancreatitis because of the proximity of the vessel to the pancreas

Can result in gastroesophageal varices

Splenectomy is the definitive treatment for bleeding

Prophylactic splenectomy is not indicated (less than 10% of splenic vein thromboses result in bleeding)

A 28-year-old woman presents with a new diagnosis of idiopathic thrombocytopenic purpura (ITP) by her hematologist. What is the next step in her management?

Steroids are the mainstay treatment for ITP. Surgery is reserved for refractory ITP.

Adult Immune or Idiopathic Thrombocytopenic Purpura

Antiplatelet IgG directed at the fibrinogen receptor (IIb/IIIa) that triggers platelet destruction in the spleen

More common in young women

Medical treatment

Successful in 15% of adults

Steroids or IV gamma globulin

Surgery

Indicated for ITP refractory to the medical treatment above

Successful in 85% of adults

Transfuse platelets if necessary after the splenic artery is ligated

What is the size of a typical spleen in ITP?

Normal size; therefore, many patients are good candidates for laparoscopic splenectomy.

A 5-year-old girl presents with a new diagnosis of ITP following an upper respiratory infection. What is the likelihood that the disease will resolve without surgery?

Surgery is rarely indicated for childhood ITP. Approximately 70% of children with ITP will have complete resolution regardless of therapy.

Childhood Idiopathic Thrombocytopenic Purpura

Occurs after viral illness

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Apr 20, 2017 | Posted by in GENERAL & FAMILY MEDICINE | Comments Off on Spleen

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