Chapter 34: Spleen Flashcards
Type of arteries: short gastric and splenic artery
End arteries
Where is the splenic vein?
Posterior and inferior to splenic artery
Serves as antigen-processing center for macrophages
Spleen
Largest producer of IgM
Spleen
Breakdown of spleen
85% red pulp
15% white pulp
Function of red pulp
Acts as a filter for aged or damaged RBCs (pitting and culling)
Red pulp: what is pitting
Pitting: removal of abnormalities in the RBC membrane
- Howell-Jolly bodies: nuclear remnants
- Heinz bodies: hemoglobin
Red pulp: what is culling
Removal of less deformable RBCs
Function of white pulp
Immunologic function; contains lymphocytes and macrophages
- Major site of bacterial clearance that lacks preexisting antibodies
- site of removal of poorly opsonized bacteria, particles and cellular debris
- antigen processing occurs with interaction between macrophages and helper T cells
An opsonin; facilitates phagocytosis -> produced in spleen
Tuftsin
Activates alternate complement pathway -> produced in spleen
Properdin
Occurs in spleen before birth and in conditions such as myeloid dysplasia
Hematopoiesis
Spleen is a reservoir for __
platelets
where are accessory spleens found?
accessory spleen (20%): most commonly found at splenic hilum
indications for splenectomy
ITP far greater than for TTP
Most common non traumatic condition requiring splenectomy
ITP
caused by anti-platelet antibodies (IgG) - bind platelets; results in decreased platelets
- petechiae, gingival bleeding, bruising, soft tissue ecchymosis
Idiopathic thrombocytopenic purpura (ITP)
What causes ITP?
from many etiologies: drugs, viruses, etc.
What does the spleen look like in ITP?
spleen is normal
When does ITP usually resolve spontaneously?
in children
Tx: ITP
Steroids (primary therapy); gamma globulin if steroid resistant
When is splenectomy indicated in ITP?
For those who fail steroids: removes IgG production and source of phagocytosis, 80% respond after splenectomy
Pre op management of ITP
Give platelets 1 hour before surgery
What is thrombotic thrombocytopenic purpura (TTP) associated with?
Medical reactions, infections, inflammation, autoimmune disease
Pathophysiology of TTP
Loss of platelet inhibition - leads to thrombosis and infarction, profound thrombocytopenia
Purpura, fever, mental status changes, renal dysfunction, hematuria, hemolytic anemia
TTP (thrombotic thrombocytopenic purpura)
Tx: TTP
80% respond to medical therapy
- Plasmapheresis (primary); immunosuppression
MCC death in TTP
most commonly due to intracerebral hemorrhage or acute renal failure
When is splenectomy indicated in TTP?
splenectomy rarely indicated
0.1% risk after splenectomy, increased risk in children
post-splenectomy sepsis syndrome (PSSS)
most common causes of post-splenectomy sepsis syndrome
1) s pneumoniae
h. influenzae, n meningitidis
what is post-splenectomy sepsis syndrome secondary to?
specific lack of immunity (immunoglobulin, igm) to capsulated bacteria
post-splenectomy sepsis syndrome is highest in patients…
with splenectomy for hemolytic disorders or malignancy
adults vs children: increased risk of mortality after developing post-splenectomy sepsis syndrome
children
what is the best age for a child if splenectomy is necessary?
5 years old: allows antibody formation; child can get fully immunized
when does post-splenectomy sepsis syndrome occur?
most episodes occur within 2 years of splenectomy
prophylactic antibiotic regimen for children
6 months of prophylactic antibiotics (controversial) - to decrease chances of post-splenectomy sepsis syndrome
vaccines needed before splenectomy
pneumococcus, meningococcus, h.influenzae
definition of hypersplenism
decrease in circulating cell count of erythrocytes and/or platelets and/or leukocytes
- and -
normal compensatory hematopoietic responses present in bone marrow
- and -
correction of cytopenia by splenectomy
- with or without -
splenomegaly
two types of hemolytic anemias - membrane protein defects
spherocytosis
elliptocytosis
most common congenital hemolytic anemia requiring splenectomy
spherocytosis
defect in spherocytosis
spectrin deficit (membrane protein) deforms RBCs and leads to splenic sequestration (hypersplenism)
pathophysiology: spherocytosis
causes pigmented stones, anemia, reticulocytosis, jaundice, splenomegaly
- spectrin deficit
tx: spherocytosis
splenectomy and cholecystectomy
- try to perform splenectomy after age 5; give immunizations first
curative in spherocytosis
splenectomy
- symptoms and mechanism similar to spherocytosis; less common
- spectrin and protein 4.1 deficit (membrane protein)
elliptocytosis
membrane protein defect: elliptocytosis
spectrin and protein 4.1 deficit
hemolytic anemia: non-membrane protein defects
- pyruvate kinase deficiency
- g6pd deficiency
- warm antibody-type acquired immune hemolytic anemia
- beta thalassemia
- results in congenital hemolytic anemia
- causes altered glucose mechanism; RBC survival enhanced by splenectomy
pyruvate kinase deficiency
mc congenital hemolytic anemia not involving a membrane protein that requires splenectomy
pyruvate kinase deficiency
- precipitated by infection, certain drugs, fava beans
- splenectomy usually not required
g6pd deficiency
management: warm antibody-type acquired immune hemolytic anemia
indication for splenectomy
- HgbA replaced with HgbS
- spleen usually auto infarcts and splenectomy not required
sickle cell anemia
most common thalassemia; due to persistent HgbF
beta thalassemia
difference between beta thalassemia major and minor
- major: beta chains affected
- minor: 1 chain, asymptomatic
is splenectomy required in sickle cell anemia?
spleen usually auto infarcts and splenectomy not required
symptoms: pallor, retarded body growth, head enlargement
beta thalassemia
management: splenomegaly in beta thalassemia
splenectomy (if patient has splenomegaly) may decrease hemolysis and symptoms
cause of death in beta thalassemia
most die in teens secondary to hemosiderosis
medical tx: beta thalassemia
blood transfusion and iron chelators (deferoxamine, deferiprone)
Symptoms: hodgkin’s disease type a
asymptomatic
symptoms: hodgkin’s disease type b
symptomatic (night sweats, fever, weight loss) –> unfavorable prognosis
stage 1: hodgkin’s disease
1 area or 2 contiguous areas on the same side of the diaphragm
stage 2: hodgkin’s disease
2 non-contiguous areas on the same side of diaphragm
stage 3: hodgkin’s disease
involved on each side of diaphragm
stage 4: hodgkin’s disease
liver, bone, lung, or any other non-lymphoid tissue except spleen
best prognosis: hodgkin’s disease
lymphocyte predominant
worst prognosis: hodgkin’s disease
lymphocyte deplete
most common hodgkin’s disease
nodular sclerosing
tx: hodgkin’s disease
chemo
mcc of chylous ascites
lymphoma
- worse prognosis than hodgkin’s; 90% are b-cell lymphomas
- generally systemic disease by the time the diagnosis is made
- tx: chemo
non-hodgkin’s lymphoma
tx: hairy cell leukemia
rarely need splenectomy
causes of spontaneous splenic rupture
mononucleosis, malaria, sepsis, sarcoid, leukemia, polycythemia vera
splenic implants; usually related to trauma
splenosis
see howell-jolly bodies
hyposplenism
most common cause of splenic artery or splenic vein thrombosis
pancreatitis
post splenectomy lab changes
increased rbcs.
increased wbcs.
increased platelets.
- if platelets > 1 x 10^6, give ASA
#1 splenic tumor overall; #1 benign splenic tumor
Hemangioma
Tx: splenic hemangioma
Splenectomy if symptomatic
1 malignant splenic tumor
non-hodgkin’s lymphoma
indications for surgery with splenic cysts
surgery if symptomatic of > 10 cm
anemia, decreased platelets
- Tx: splenectomy for symptomatic splenomegaly
sarcoidosis of spleen
rheumatoid arthritis, hepatomegaly, splenomegaly
- Tx: splenectomy for symptomatic splenomegaly
felty’s syndrome
tx: splenic abscess
splenectomy usual (bleeding risk with percutaneous drainage)
Tx: echinococcal splenic cyst
splenectomy
results of splenectomy / hyposplenic condition - erythrocytes
- howell-jolly bodies (nuclear fragments)
- heinz bodies (hemoglobin deposits)
- pappenheimer bodies (iron deposits
- target cells
- spur cells (acanthocytes)
results of splenectomy / hyposplenic condition -
platelets
transient thrombocytosis
results of splenectomy / hyposplenic condition
- leukocytes
transient leukocytosis
persistent lymphocytosis
persistent monocytosis
guidelines for prevention of postsplenic sepsis
- vaccinate with polyvalent pneumococcal vaccine at least 10-14d prior to splenectomy
- if splenectomy urgent: wait 14d post procedure to vaccinate
- for high risk patients (immunosuppressed, children
