ABSITE - Spleen - Questions

A 29-year-old female with hereditary spherocytosis is recommended to undergo splenectomy. At what time point is trivalent immunization recommended? A. 1-month pre-op B. 2-weeks pre-op C. 1-week pre-op D. 1-week post-op E. 2-weeks post-op

2-weeks pre-op Correct. Although rare, overwhelming post-splenectomy infection (OPSI) is a life-threatening complication that can occur weeks, months, or years following splenectomy. Encapsulated organisms such as Haemophilus, Streptococcus pneumoniae, and Meningococcus are most commonly responsible. The Centers for Disease Control and Prevention recommends vaccination against these three organisms 2 weeks prior to elective splenectomy.

An otherwise healthy 55-year-old female underwent a routine lipoma removal of the back. The procedure was completed without difficulty. Cefazolin was given as antibiotic prophylaxis. Twenty four hours post-op, the patient is noted to develop jaundice, fatigue, and splenomegaly. Direct Coombs' test is positive. What is the most likely diagnosis? A. Sickle cell anemia B. Splenic abscess C. Splenic vein thrombosis D. Immune thrombocytopenic purpura E. Autoimmune hemolytic anemia

Autoimmune hemolytic anemia Correct. Acquired autoimmune hemolytic anemia occurs due to the production of antibodies directed against RBC membrane proteins, and can either be idiopathic or secondary to infection or drugs (e.g. penicillin, hydralazine, quinidine). It typically presents in patients over the age of 50, with a higher incidence in females. Symptoms can include acute onset of jaundice, anemia, fevers, and splenomegaly. A positive direct Coombs' test can confirm the diagnosis and differentiate from other forms of hemolytic anemia. Sickle cell anemia, splenic abscess, and splenic vein thrombosis do not have positive direct Coombs' test, while the onset of ITP in adults is typically chronic.

A 35-year-old female is referred by her primary care physician after reporting an increase in bleeding during her last 3 menstrual cycles and a tendency to bruise easily. She denies taking any medications, or using tobacco or recreational drugs. She has platelet count of 40,000 and demonstrates oral mucosal bleeding. You suspect she has immune thrombocytopenic purpura (ITP). What do you recommend for treatment? A. Splenectomy B. Platelet transfusion C. Corticosteroids D. Intravenous gamma-immunoglobulin E. Romiplostim (an agonist for thrombopoietin receptor)

Corticosteroids Correct. The treatment of ITP includes standard measures to treat ongoing bleeding, medical therapies designed to increase platelet count, and splenectomy. Platelet transfusions should be limited unless patients are actively bleeding as their effect is short lived. Corticosteroid therapy produces an initial response in most patients. Although IV gamma globulin is also effective, its cost and associated side effects limit its use as first-line therapy. In patients who have not achieved a sustained remission with medical therapy, elective splenectomy is recommended. Treatment for ITP after splenectomy failure has been accomplished with various new agents. Romiplostim, a fusion protein agonist for thrombopoietin receptor administered by subcutaneous injection, is an agent used for patients who fail to respond to splenectomy.

After undergoing splenectomy for ITP, a patient has persistent disease concerning for a missed accessory spleen, and a technetium scan is ordered to localize it. Which is the most common location for an accessory spleen? A. Mesentery B. Hilar region C. Lesser sac D. Diaphragm E. Tail of pancreas

Hilar region Correct. Up to 15-30% of patients with ITP may have accessory spleens, and failure to retrieve them at the time of initial surgery may lead to symptom recurrence. The most common location is the hilar region (54%), followed by the splenic vascular pedicle (25%) and greater omentum (12%).

Hypersplenism is defined as increased splenic function manifest clinically by the decrease in one or more of the circulating blood elements. Which of the following are specific factors associated with hypersplenism? A. The absence of megakaryocytes in patients with thrombocytopenia confirms hypersplenism. B. Left upper quadrant pain is the most significant symptom of massive splenomegaly. C. Splenomegaly is mandatory for hypersplenism to exist. D. Hypersplenism can exist either with an anatomically normal spleen and a disease related to circulating cells or with normal circulating cells and a primary alteration in the spleen, either anatomically or functionally.

Hypersplenism can exist either with an anatomically normal spleen and a disease related to circulating cells or with normal circulating cells and a primary alteration in the spleen, either anatomically or functionally. Correct. The specific criteria for hypersplenism are (a) documented anemia, thrombocytopenia, or leukopenia; (b) normal compensatory response by the bone marrow to correct cytopenia; and (c) correction of the cytopenia by splenectomy. Some definitions of hypersplenism may also include the criterion of splenomegaly. If an enlarged spleen is considered mandatory for hypersplenism, then diseases or disorders related to abnormalities in circulating blood cells such as immune thrombocytopenia purpura or autoimmune hemolytic anemia are not included in this category. Alternatively, hypersplenism includes disorders in which the spleen is normal anatomically and the disease is related to the circulating cells, with a second category in which circulating cells are normal and there is a primary alteration of the spleen either anatomically or functionally. For either situation, the spleen is the site of destruction for one or more circulating blood elements. In cases of a significantly enlarged spleen, additional symptoms relate to the mass effect from the spleen on adjacent organs. The most important symptom is early satiety with accompanying weight loss as the stomach is compressed between the liver and the enlarged spleen. Hypersplenism is the most important indication for elective isolated splenectomy to reverse the cytopenia and often to relieve compressive symptoms from splenomegaly.

Which of the following statements is true concerning the technical aspects of splenectomy? A. In patients undergoing splenectomy for immune thrombocytopenia purpura, platelet transfusion should begin at the time of incision. B. In planned splenectomy, vaccination with Pneumovax as well as vaccination against Haemophilus influenzae and Neisseria meningococcus should be given 10 to 14 days prior to surgery if possible. C. The technique of laparoscopic splenectomy should be applied to patients only with small or normal-size spleens. D. The preferred surgical technique for massive splenectomy begins with delivery of the spleen from its lateral attachments.

In planned splenectomy, vaccination with Pneumovax as well as vaccination against Haemophilus influenzae and Neisseria meningococcus should be given 10 to 14 days prior to surgery if possible. Correct. The choices of operations available currently to approach the spleen in an elective manner are open splenectomy, laparoscopic splenectomy, and partial splenectomy. Certain principles apply to all patients undergoing elective splenectomy. First, all patients should receive appropriate preoperative vaccination with pneumococcal vaccine and possibly also vaccination against H. influenzae and N. meningococcus 10 to 14 days prior to the procedure if possible. The operative approach for open splenectomy involves either a midline abdominal or left subcostal incision. A long midline incision should be employed in patients who have massive splenomegaly. One approach, particularly for small spleens that are mobile, is to initially divide the lateral attachments and place packs in the left upper quadrant to elevate the spleen and then proceed with the vascular dissection. This technique should be discouraged particularly in patients who are thrombocytopenic or in patients with massive splenomegaly. In this situation, the splenectomy should start by obtaining vascular control before manipulating the spleen, which could lead to capsule rupture and significant blood loss. For patients with immune thrombocytopenia purpura, platelets should not be given until the spleen is removed or at least until arterial flow is controlled because of the clearance of transfused platelets by the spleen in this disease. Virtually all splenectomies can now be approached laparoscopically. Even patients with massive splenomegaly are now approached with laparoscopic splenectomy with the use of a hand port. There may be a higher incidence of conversion to an open procedure with spleens greater than 2,000 g.

Hereditary spherocytosis is the most common of the congenital hemolytic anemias. Which of the following statements is true concerning this condition? A. Jaundice and biliary tract conditions are often the primary indication for surgery. B. The condition is transmitted as a sex-linked chromosomal abnormality. C. Splenectomy should be performed at the time of diagnosis regardless of the patient's age. D. Splenectomy corrects the condition such that spherocytes will no longer be seen on blood smear.

Jaundice and biliary tract conditions are often the primary indication for surgery. Correct. Hereditary spherocytosis, also known as congenital hemolytic jaundice or familial hemolytic anemia, is an autosomal dominant disease affecting 1 in 5,000 individuals. Diagnosis is primarily made by evaluation of red blood cell smear showing a large number of spherocytes. Patients with hereditary spherocytosis have mild to moderate anemia, splenomegaly, and jaundice. Patients may have intermittent flares of disease that cause significantly increased rates of hemolysis, causing jaundice. Between 30% and 60% of patients have been reported to have pigmented gallstones due to breakdown of hemoglobin. The treatment for hereditary spherocytosis is splenectomy and is indicated in virtually all patients. This treatment does not remove the spherocytes, but it does relieve all symptoms. The major question involving management of these patients is the time of the splenectomy because of the increased incidence of overwhelming postsplenectomy sepsis in very young children. It is usually recommended that patients wait until after age 4 to 6 years before undergoing to splenectomy.

You are performing a laparoscopic splenectomy for treatment of refractory ITP on a 45-year-old man. His preoperative platelet count is 50,000. As you retract the omentum from the left upper quadrant, blood wells up around the superior pole of the spleen near the diaphragm. Which sequence of events represents the best plan for intra-operative management of this situation? A. Ligate the splenic artery, take down the gastro-splenic ligament, transfuse platelets, pack the left upper quadrant. B. Pack the left upper quadrant, transfuse platelets, ligate the splenic artery, take down the gastro-splenic ligament. C. Take down the gastro-splenic ligament, transfuse platelets, pack the left upper quadrant, ligate the splenic artery. D. Pack the left upper quadrant, take down the gastro-splenic ligament, ligate the splenic artery, transfuse platelets. E. Transfuse platelets, pack the left upper quadrant, take down the gastro-splenic ligament, ligate the splenic artery.

Pack the left upper quadrant, take down the gastro-splenic ligament, ligate the splenic artery, transfuse platelets. Correct. Omental attachments to the spleen are common and failure to recognize this can result in splenic bleeding early in a procedure. The initial step to control capsular bleeding is packing. Platelets should not be transfused prior to ligation of the splenic artery to avoid consumption of the platelets by splenic macrophages. The splenic artery is best ligated by isolating it along the superior border of the tail of the pancreas in the lesser sac. Access to the lesser sac is gained by dividing the gastrosplenic ligament.

A 27-year-old man is referred to you for evaluation of a 4.5-cm simple cystic lesion in the inferior pole of the spleen seen on a CT scan done for an evaluation of right flank pain. He denies left-sided pain or early satiety. What is the most appropriate next step in her management? A. Reassurance along with periodic follow up to evaluate symptoms. B. Percutaneous aspiration to evaluate for malignancy. C. Mesenteric angiography with splenic artery. D. Splenectomy including exploration for accessory spleens. E. Endoscopic ultrasound to better characterize the fluid complexity.

Reassurance along with periodic follow up to evaluate symptoms. Correct. Simple cysts of the spleen are a common finding on axial imaging. When the patient is asymptomatic and the cyst architecture is uniform, the malignant potential is very low. Splenectomy would only be considered for a symptomatic cyst. There is no need for additional procedures such as endoscopic ultrasound to characterize this low risk lesion. Embolization of the splenic artery would not likely lead to resolution of a simple cyst and is not indicated.

Which of the following hematologic disorders is unlikely to respond to splenectomy? A. Idiopathic thrombocytopenic purpura B. Autoimmune hemolytic anemia C. Thalassemia D. Sideroblastic anemia E. Hereditary spherocytosis

Sideroblastic anemia Correct. Hematologic disorders that respond to splenectomy are those conditions where blood cells are destroyed and removed by the spleen. Idiopathic thrombocytopenic purpura is the most common hematologic indication for splenectomy, and is characterized by IgG antibodies against platelets. Autoimmune hemolytic anemia, likewise, is an autoimmune disorder of antibodies against RBC's. Patients with symptomatic thalassemia and hereditary spherocytosis may also benefit from splenectomy. Sideroblastic anemia, by contrast, does not respond to splenectomy.

You are consulted on a 55-year-old homeless woman admitted for sepsis with documented gram-positive bacteremia. A CT scan of the abdomen obtained today is shown below (multifocal abscesses). She has been started on broad-spectrum antibiotics. What is the most appropriate next step in her management? A. Mesenteric angiography and embolization B. Image-guided percutaneous drain placement C. Splenectomy D. Fine needle aspiration and culture of splenic lesions E. Administration of IgG

Splenectomy Correct. The image demonstrates multiple splenic abscesses likely seeded from the patient's bacteremia producing septic emboli. Optimal treatment is splenectomy. Image-guided drain placement may be an option for a marginally stable patient with a single abscess, but is prone to failure and complication. IgG is typically used in the treatment of ITP, not splenic abscess. FNA and culture plays no role in the treatment of this disease process.

A 47-year-old man with a history of chronic pancreatitis secondary to alcohol presents with upper gastrointestinal bleeding. Upper endoscopy reveals several large varices along the greater curvature of the stomach. What is the most likely underlying diagnosis and indicated treatment? A. Portal hypertension: transjugular intrahepatic portocaval shunt B. Splenic vein thrombosis: splenectomy C. Hypersplenism: splenectomy D. Hypersplenism: splenic artery embolization E. Splenic vein thrombosis: portocaval shunt

Splenic vein thrombosis: splenectomy Correct. Chronic pancreatitis is the most common cause of splenic vein thrombosis. Thrombosis of the splenic vein can lead to sinistral or "left-sided" portal hypertension with the development of splenomegaly and gastric varices at the site of venous collaterals diverted through the short gastric vessels. Upper gastrointestinal bleeding is the most common presentation of this disease and is an indication for splenectomy. Traditional procedures to treat portal hypertension do not affect this disorder.

Which of the following statements regarding pre-operative splenic artery embolization is correct? A. The goal of pre-operative splenic artery embolization is to facilitate easier identification of the splenic artery intra-operatively. B. The pancreatica magna must be embolized to ensure complete splenic artery embolization. C. Successful splenic artery embolization results in about 80% of splenic parenchymal becoming ischemic. D. Microspheres or gelatin powder are used to embolize the splenic artery. E. Splenic artery embolization is most useful before open splenectomy and adds little benefit to laparoscopic splenectomy.

Successful splenic artery embolization results in about 80% of splenic parenchymal becoming ischemic. Correct. Successful splenic artery embolization results in about 80% of splenic parenchymal becoming ischemic. Splenic artery embolization may be used pre-operatively before laparoscopic splenectomy to reduce blood loss. Small coils and absorbable gelatin sponges can be used to embolize the individual branches of the splenic artery, with care taken not to embolize the pancreatica magna as this can result in ischemia to the pancreatic tail. Microspheres and gelatin powder should be avoided due to their small size and ability to migrate to other organs and cause unintended tissue ischemia.

During an exploratory laparotomy for blunt trauma in a 27-year-old woman, you find an isolated Grade III injury of the spleen with two horizontal linear lacerations in the mid-portion. The patient's vital signs are stable and the Hct is 34. Which is the most appropriate technique for managing this situation? A. Total splenectomy B. Partial splenectomy C. Suture of the lacerations D. Packing and temporary abdominal closure E. Splenorrhaphy with polyglactin mesh

Suture of the lacerations Correct. Most Grade III splenic injuries can be managed with simple or mattress sutures. Some surgeons will use pledgets to buttress the repair and to prevent additional bleeding during tying of the sutures. Total splenectomy is reserved for situations when other techniques are unsuccessful or for higher grades of injury. Partial splenectomy is usually not possible with injuries to the mid-portion of the spleen. Splenorrhaphy is unnecessary if suture closure is successful. This patient is stable so packing is not indicated.

The problem of overwhelming postsplenectomy sepsis is a significant concern. Which of the following statements is true regarding this consequence of splenectomy? A. The risk of postsplenectomy septic episodes is essentially the same throughout life. B. The indication for splenectomy is not a factor in predicting the incidence of postsplenectomy sepsis. C. The risk of postsplenectomy sepsis is unrelated to age. D. The mortality rate of postsplenectomy sepsis is between 50% and 60% in most series.

The mortality rate of postsplenectomy sepsis is between 50% and 60% in most series. Correct. The changes seen after splenectomy in immune function are most importantly manifested by the phenomenon of overwhelming postsplenectomy sepsis. It is clear that the postsplenectomy sepsis is inversely related to age. In a younger child, the risk of developing this condition is greater and the impact of the infection will be more severe. This feature has clinical implications because elective splenectomies are not performed for patients with hereditary erythrocyte syndromes until after ages 6 to 10 years. These postsplenectomy septic episodes occur within the first 2 years after splenectomy in 80% of cases. In adults, the reason for splenectomy also relates to the incidence of sepsis. In trauma, the incidence of sepsis in a large series was 1.4%, whereas in thalassemia, the incidence was 24.8%. Patients with any associated immunodeficiency such as malignancy or patients undergoing chemotherapy for treatment of Hodgkin disease are also at increased risk for sepsis. The mortality rate of postsplenectomy sepsis is between 50% and 60% in most series. The types of organisms that account for infection are typically encapsulated organisms, with the most common being Streptococcus pneumoniae, which accounts for 50% of septic episodes in most series. In decreasing order of frequency, other bacteria associated with postsplenectomy sepsis are Haemophilus influenzae, Neisseria meningitidis, β-hemolytic Streptococcus, and Staphylococcus aureus. The current recommendation for patients who are having elective splenectomy is to vaccinate susceptible individuals with Pneumococcus strains, which is ideally performed 2 weeks before operation.

Hematologic consequences of splenectomy include which of the following? A. The presence of red cells with Howell-Jolly bodies, Heinz bodies, and Pappenheimer bodies B. Persistent lymphopenia and thrombocytopenia C. Persistent thrombocytosis and leukocytosis D. Transient thrombocytopenia and leukopenia

The presence of red cells with Howell-Jolly bodies, Heinz bodies, and Pappenheimer bodies Correct. There are hematologic changes following splenectomy in circulating cells that can be predicted from the splenic functions of culling, pitting, and serving as a reservoir for platelets. The changes in circulating blood cells after splenectomy or in cases of hyposplenism may affect the erythrocytes, leukocytes, and platelets. Over time, the intracytoplasmic inclusions in the red cells that are normally cleared by the spleen accumulate, resulting in the presence Howell-Jolly bodies, Heinz bodies, and Pappenheimer bodies as well as target cells with excess red blood cell membrane and occasionally increases in circulating nucleated red blood cells or reticulocytes. As the spleen is the organ of storage for large proportions of platelets, a splenectomy often results in thrombocytosis, with platelet counts postsplenectomy ranging from 500,000/mm3 up to 1 million/mm3 in some cases. This increased platelet count is usually transient and may be a reflection of the fact that the spleen, while being a storage organ for platelets, may not be a primary area of platelet destruction after the typical half-life of 10 days. Immediate response after splenectomy in white blood cells is leukocytosis, again reflecting the storage of a large proportion of white blood cells in the spleen. As in thrombocytosis, the effect is transient; however, there may be long-term increases in the proportion of circulating lymphocytes and monocytes after splenectomy. Preserving even a small amount of spleen can preserve splenic function in the clearance of senescent blood cells.

The major functions of the spleen can be divided into two general categories of hematologic and immunologic functions. Which of the following statements is true regarding the normal function of the spleen? A. The spleen provides the environment for generation of the humoral but not cellular aspects of the normal immune response. B. The primary hematologic function of the spleen is removal of senescent red blood cells or remodeling of abnormal red cells with various deformities. C. Throughout a normal lifetime, the spleen continues to serve as an important secondary source of hematopoiesis for all cell types. D. Destruction of platelets and leukocytes is an important normal physiologic function of the spleen.

The primary hematologic function of the spleen is removal of senescent red blood cells or remodeling of abnormal red cells with various deformities. Correct. The major functions of the spleen can be divided into two general categories of hematologic functions and immunologic functions. The primary hematologic function of the spleen is removal of senescent erythrocytes or remodeling of abnormal red blood cells with various abnormalities. This physiologic filtration function is increased in disease states to produce hypersplenism. The spleen may play a minor role in hematopoiesis and storage of blood cells that can be mobilized for circulation, with the stored cells being predominately platelets. Pathologic destruction of red cells occurs in diseases such as hereditary spherocytosis or elliptocytosis in which a genetic defect creates abnormal red cell pliability, limiting its passage through the red pulp of the spleen. A second physiologic process involving circulating erythrocytes is remodeling or pitting, which is partial removal of the cell membrane typically associated with cytoplasmic inclusions. The destruction of other circulating cellular elements of the blood (platelets and leukocytes) is more in the realm of pathophysiology of the spleen than normal physiologic function. The disease process in which these cells are removed are either related to autoantibodies to cell surface elements or related to hypersplenism. The spleen serves as a potential source of hematopoiesis of all cell types during gestation. In healthy humans, there is thought to be very little if any production of red blood cells, granulocytes, or platelets. The immunologic function of the spleen is to generate an immune response to antigens that are identified and cleared from the bloodstream. Either opsonized antigens or specific encapsulated microorganisms are important examples of target antigens trapped by the spleen. The spleen is an ideal environment for generation of either a cellular or humoral immune response. Many cell types are necessary for stimulation of the immune response, including phagocytic cells, dendritic cells, T cells, and B cells, which may form general follicles to generate a specific antibody response. The spleen is also involved in nonspecific immune responses. It is the site of synthesis of both properdin and tuftsin, which are opsonins.

Immune thrombocytopenia purpura (ITP) is a disease characterized by autoimmune destruction of platelets with clinical manifestations of thrombocytopenia and susceptibility to easy or excessive bleeding. Which of the following statements is true concerning ITP? A. The first-line treatment for ITP includes high-dose steroids, which will usually produce both an initial and sustained response with overall return of the platelet count to normal. B. Acute ITP, which generally occurs in children following an upper respiratory illness, should be considered an indication for splenectomy. C. The role of the spleen in ITP is both in the production of immunoglobulin G antibody to a platelet antigen and as the primary site of platelet destruction. D. Splenectomy results in a durable cure of ITP in more than 90% of patients.

The role of the spleen in ITP is both in the production of immunoglobulin G antibody to a platelet antigen and as the primary site of platelet destruction. Correct. ITP may be classified as an acute form or a chronic form. Acute ITP generally occurs in children younger than age 8 years following a viral upper respiratory illness. Of all children with acute ITP, spontaneous remission occurs in 80% to 90% of cases. Only 8% to 10% of patients of adults who develop ITP have remission; most develop chronic ITP. Chronic ITP accounts for most cases considered for splenectomy. The average age at diagnosis is the fourth decade of life, and the disease affects women more commonly than men. The pathophysiology of ITP is development of immunoglobulin G antibody to a platelet antigen. The spleen plays a predominate role in this disease because it may be the site of initial antibody production, it is almost certainly the site of continued antibody production, and in most patients it is the primary site of platelet destruction. The treatment of ITP includes standard measures to treat ongoing bleeding, medical therapies designed to increase platelet counts, and splenectomy. High-dose corticosteroids produce an initial response in most patients, but unfortunately this response is not sustained. Approximately 75% of patients have an increase in platelet count that is significant within 24 hours of starting high-dose steroids. However, only 15% to 25% of patients have a sustained remission with chronic ITP following steroid therapy. The second line of treatment for chronic ITP has been the administration of intravenous immunoglobulin G. In patients who have not achieved a sustained remission with medical therapy, which is most patients with chronic ITP, an elective splenectomy is recommended. Based on a recent analysis of 135 institutional reports and more than 5,000 cases, the percent of patients who achieved a normal platelet count after splenectomy was 68.9%. In assessing disease characteristics, demographic features such as age and sex, duration of illness, platelet count, and response to medical therapy, there appears to be no factor with a significant predictive value of response to therapy. The overall mortality from splenectomy in the patient population was 0.8%, which may be somewhat lowered by performance of laparoscopic splenectomy.

The pathophysiology of immune thrombocytopenic purpura (ITP) involves: A. Decreased IgG production in the spleen of ITP patients. B. Destruction of platelets within the bone marrow. C. Development of IgM antibodies to a platelet antigen. D. The spleen as the site of initial antibody production targeting platelets. E. Down-regulation of megakaryocytes within the bone marrow.

The spleen as the site of initial antibody production targeting platelets. Correct. The pathophysiology of ITP is development of an IgG antibody to a platelet antigen. This is most commonly directed against the fibrinogen receptor (glycoprotein IIb/IIIa and IR/IX). The spleen plays a predominant role in this disease as it may be the site of initial antibody production. In most patients, the spleen is the primary site of platelet destruction. Antibody levels indicate that overall IgG production in spleens from patients with ITP is markedly increased over individuals with normal spleens. The spleen is also the predominant site of platelet destruction. Bone marrow analysis shows increased megakaryocyte production as compensatory mechanism to the thrombocytopenia.

Which of the following statements describing the vascular anatomy of the spleen is true? A. The splenic vein generally travels outside the parenchyma of the pancreas just at its superior border, allowing access for early ligation. B. The splenic artery generally travels within the parenchyma of the pancreas such that it is inaccessible for proximal ligation. C. The splenic artery usually divides into superior and inferior polar branches, which can be individually ligated, allowing partial splenectomy. D. The important function of the spleen as a filter for damaged blood cells requires that splenic blood flow be in excess of 10% of total cardiac output.

The splenic artery usually divides into superior and inferior polar branches, which can be individually ligated, allowing partial splenectomy. Correct. The splenic artery is one of the three major trunks along with the left gastric artery and common hepatic artery branching off from the celiac axis. The splenic artery generally travels outside the parenchyma of the pancreas just at the superior border, although curves that travel inferiorly may be completely covered by the posterior surface of the pancreas, whereas superior curves may be well away from the pancreatic surface. It is these curves, which become more cranial, that are the optimal place to provide a ligature to control the splenic artery during procedures in which there is significant thrombocytopenia or for enlarged spleens. The first major splenic branch occurs approximately 2 to 3 cm from the hilum and is called the superior polar artery. The main artery then divides into anywhere between three and five segmental branches that enter along the trabecula of the spleen. Additional blood supply to the spleen comes from the left gastroepiploic artery via the short gastric vessels. The splenic vein is formed by segmental venous branches that leave the trabecula and coalesce into the main splenic vein in the hilum of the spleen. The splenic vein is intimately associated with the posterior surface of the tail and body of the pancreas to its junction with the superior mesenteric forming the portal vein. The blood flow to the spleen in the typical adult is estimated to be 200 to 300 mL/min or approximately 5% of the cardiac output.

A 51-year-old male is diagnosed with chronic lymphocytic leukemia during workup of pancytopenia. He has required transfusions at least every other week for persistent pancytopenia that has not responded to chemotherapy. He complains of left-sided abdominal pain and his spleen is palpable 4 cm below the left costal margin. A CT is obtained (see below= splenomegaly). The next step in management should be A. Radiation therapy B. Splenic artery embolization C. IVIG D. Partial splenectomy E. Total splenectomy

Total splenectomy Correct. Splenectomy is an appropriate choice in this situation. Radiation therapy has little effect on splenomegaly. Splenic artery embolization is usually ineffective as therapy although it is sometimes used preoperatively to reduce splenic size. Partial splenectomy and IVIG are ineffective.

The risk of dying from overwhelming post-splenectomy infection (OPSI) A. is greatest after splenectomy for trauma. B. decreases as the interval after splenectomy increases. C. is greatest in the elderly. D. eventually becomes identical to the risk in the normal population. E. is eliminated by taking prophylactic penicillin.

decreases as the interval after splenectomy increases. Correct. An increased risk of sepsis and septic shock is directly related to splenectomy at any age. Children less than 15 years of age have a greater overall risk of developing overwhelming post-splenectomy infection (OPSI) compared with adults (0.13% to 8.1% versus 0.28% to 1.9%). Splenectomized infants and young children are even more susceptible for pneumococcal sepsis. The incidence of OPSI is related to the underlying disease. Historically the incidence of sepsis after splenectomy caused by trauma is lower than after splenectomy for hematologic disorders or malignancy. Increased mortality is also seen in patients with lymphoreticular disease, and in those undergoing extensive chemotherapy and radiation therapy. Published information indicates that most cases of OPSI present in the initial two years after splenectomy, with 50% to 80% within this period. The mortality of OPSI is 50% or greater. The risk of OPSI is lifelong, and OPSI has been reported more than 40 years after operation. Prophylactic penicillin is of no proven benefit.