Spleen

What is the arterial blood supply to the spleen?

• Splenic artery from the celiac plexus; short gastric arteries (vasa brevia) from the gastroepiploic artery

What is the relationship between the splenic artery and the splenic vein?

• The splenic artery is anterior and superior to the splenic vein

What percentage of patients have an accessory spleen?

• ~20%

Where is an accessory spleen most commonly found?

• The accessory spleen is found in the region of the splenic hilum and vascular pedicle in 80% of cases

What ligaments suspend the spleen?

• Splenocolic, gastrosplenic, phrenosplenic, and splenorenal ligaments

What is the function of the spleen?

• Hematologic: removal of cytoplasmic inclusions in the erythrocytes (pitting); destruction of senescent erythrocytes (culling); hematopoiesis in the fetus or in patients with bone marrow destruction; reservoir for platelets and granulocytes

• Immunologic: production of the opsonins tuftsin and properdin; antibody production in germinal follicles; filtration and trapping of circulatory antigens; lymphocyte stimulation and proliferation

What is the largest producer of IgM in the body?

• The spleen

What 2 opsonins are produced by the spleen?

• Tuftsin and properdin

What is idiopathic thrombocytopenic purpura (ITP)?

• A condition in which circulating IgG antiplatelet antibodies destroy platelets

In which patient population does ITP usually resolve spontaneously?

• Children (rarely requires surgery)

What is the first-line therapy for ITP?

• Corticosteroids (Note: plasmapheresis and γ globulin can be used as adjuncts)

What time period should elapse prior to performing splenectomy in an ITP patient being treated with steroids?

• 6 weeks

When should platelets be administered during splenectomy for ITP?

• Once the splenic hilum is ligated

What is the most common nontraumatic condition requiring splenectomy?

• ITP

What is the most common cause of failure to correct thrombocytopenia after splenectomy for ITP?

• Unidentified accessory spleen

What pentad of clinical findings can be seen with thrombotic thrombocytopenic purpura (TTP)?

• Thrombocytopenic purpura, fever, renal failure, hemolytic anemia, and neurologic manifestations

What is the treatment of choice for TTP?

• Daily plasmapheresis and fresh frozen plasma administration

True or False: G6PD deficiency is an indication for splenectomy?

• False: G6PD deficiency is not an indication for splenectomy

What is the most common congenital hemolytic anemia not involving a membrane protein that requires splenectomy?

• Pyruvate kinase deficiency

What is the most common congenital hemolytic anemia requiring splenectomy?

• Spherocytosis

What is the definition of hypersplenism?

• A decrease in the circulating cell count of any combination of leukocytes/erythrocytes/platelets with a normal compensatory hematopoietic response from bone marrow with correction of cytopenia by splenectomy with/without splenomegaly

What is Felty syndrome?

• Splenomegaly, rheumatoid arthritis, and neutropenia (perform splenectomy for symptomatic patient with IgG present on the surface of neutrophils)

What is the #1 splenic tumor overall?

• Hemangioma

What is the #1 benign splenic tumor?

• Hemangioma

What is the most common primary splenic neoplasm?

• Non-Hodgkins lymphoma

What is the first-line therapy for hairy cell leukemia?

• Cladribine and Pentostatin (purine nucleoside analogs)

What are indications for surgery for a splenic cyst?

• If >5 cm or symptomatic

When is the optimal time to administer vaccines to prevent overwhelming postsplenectomy sepsis (OPSI) after splenectomy?

• If possible 10 to 14 days before splenectomy; if emergent wait at least 14 days postprocedure to vaccinate (often given postoperative day 5 in trauma patients secondary to poor follow-up)

What is the optimal time period to wait before performing a splenectomy in a child?

• Until age 5 (allows antibody formation and full immunization)

When do most cases of overwhelming OPSI occur?

• Within 2 years of splenectomy

What are the most common bacteria involved in overwhelming OPSI?

• Streptococcus pneumoniae

What measures are taken to help prevent overwhelming OPSI?

• Vaccinate against Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis; antibiotic prophylaxis for children <5 years of age; prophylactic penicillin for all minor illnesses/infections; immediate medical evaluation for febrile illness; MedicAlert bracelet

What is the most consistent finding in the blood in all patients following splenectomy?

• Howell-Jolly bodies

What will you find on a peripheral blood smear in a patient following splenectomy?

• Howell-Jolly bodies; Heinz bodies; Pappenheimer bodies; target cells; polychromatophilia (reticulocytosis)

What are Howell-Jolly bodies?

• Basophilic nuclear remnants (clusters of DNA)

What are Heinz bodies?

• Formations of damaged hemoglobin component molecules (usually through oxidation)

What are Pappenheimer bodies?

• Abnormal granules of iron formed by phagosomes that have engulfed excessive amounts of iron

What is the most common intra-abdominal organ injured with blunt trauma?

• The spleen

What is a grade III splenic injury?

• Hematoma: subcapsular, >50% surface area or expanding, ruptured subcapsular or parenchymal hematoma; intraparenchymal hematoma, 5 cm or expanding

• Laceration: >3 cm in parenchymal depth or involving the trabecular vessels

How would you manage a hemodynamically stable patient with a splenic injury and contrast extravasation on the arterial phase of abdominal CT scan?

• Controversial: operative intervention versus angiographic embolization

How would you manage a hemodynamically stable patient with a splenic injury without contrast extravasation on abdominal CT scan?

• Admission to ICU; serial hematocrit, vital signs, serial abdominal examinations; bed rest; NPO; if stable at 48 to 72 hours transfer to step-down unit, activity as tolerated, and advance diet

What classic criteria are used for the nonoperative management of splenic injury?

• Absence of contrast extravasation on CT; absence of other associated injuries requiring surgical intervention; absence of health conditions with an increased risk for bleeding (coagulopathy, hepatic failure, anticoagulants, specific coagulation factor deficiency); hemodynamic stability; negative abdominal examination; splenic injury grade I to III

What are the indications for splenectomy in a patient with splenic injury?

• Patients with multiple associated injuries (neuro injuries), unstable, or in DIC

After performing an exploratory laparotomy for trauma, you incidentally discover a capsular tear of the spleen; how should you control the bleeding?

• With compression or with topical hemostatic agents

How should you manage a patient with an injury to the central portion of the spleen extending into the hilum?

• Splenectomy