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
ligaments
a. splenophrenic
b. splenorenal
c. splenocolic
d. 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 pulp
a. 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 Functions
A. Filtering – splenic blood flow – 350
ml/day
1. removal of abnormal red blood cells
– approximately 20 ml of aged RBC are
removed daily
2.removal of abnormal WBC,
plateletes
B. Immunologic Function
1. opsonin production
2. antibody synthesis (IgM)
3. protection from infection
C. Storage Function
1. 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. Diagnostic
A. Evaluation of size
1. physical examination
a. not normally palpable
b. felt in 2% of healthy adults
c. no significant dullness elicited
by percussion over spleen
d. 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
pathology
3. 99 Tc colloid
B. Evaluation of function
1. hypersplenism – reduction in number of RBC,
WBC, plateletes
2. increase in cellular destruction results in
compensatory rise in production in the bone marrow
 reticulocytosis
IV. Pathologies
A. Rupture of the Spleen
1. Etiology – disruption of the spleen’s
parenchyma, capsule, and blood supply
a. spleen is the most commonly
injured organ following blunt
trauma
b. 2% splenic injury during surgery
in the LUQ – Gastric surgery
c. spontneous rupture – hematologic
disorders
CT scan of splenic and liver trauma
2. Pathology
a. splenic rupture
i. intraperitoneal bleed
ii. 90% of blunt trauma
b. delayed rupture
i. 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 manifestation
a. hypovolemia/tchycardia
b. hypotension
c. localized (LUQ) or generalized
abdominal pain
d. Kehr’s sign – pain at the tip of
the left shoulder  diaphragmatic
irritation
e. Balance’s sign ( mass or fixed
dullness at the left upper quadrant
4. diagnostic studies
a. CBC – serial Hct determination
leukocytosis
b. x-ray of the abdomen
i. fractured ribs
ii. elevated immobile
diaphragm
iii. enlarged splenic shadow
iv. medial displacement of
gastric shadow
v. widening shadow between
splenic flexure and preperitoneal
fat
c. CT scan
d. angiography
5. Treatment – surgery
a. 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. Hypersplenism
1. Primary hyperslenism
a. 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 hypertension
i. splenic congestion
ii. most common cause of
secondary hypersplenism
iii. does not warrant
splenectomy
b. splenic vein thrombosis
i. massive splenomegaly
ii. thrombosis secondary to
pancreatitis
iii. associated with bleeding
esophageal varices
iv. cured by splenectomy
CT and Angiogram of splenic vein
thrombosis
c. other causes
i. neoplasms – leukemia,
lymphoma, metastatic
carcinoma
ii. myelproliferative disorders
iii. increase in RBC
destruction – thalassemia
major
iv. disorders in immune response
– infectious mononucleosis,
Felty’s syndrome (rheumatoid
arthritis, splenomegally,
neutropenia)
v. diseases that infiltrate the
spleen – amyloidosis, sarcoidosis
Splenic tumor
V. Splenectomy
A. Absolute Indications for Splenectomy
1. 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 splenectomy
1. congenital hemolytic anemias
2. sickle cell anemia
3. idiopathic autoimmune hemolytic
anemia
4. Thrombocytic thrombocytopenic
purpura
5. Felty’s syndrome/Sarcoidosis (non-caseating
granulomas)/Gaucher’s 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. Hodgkin’s lymphoma
9. Non-hodgekin’s 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. Complications
1. left lower lobe atelectasis – most
common
2. subphrenic hematoma
3. subphrenic abscess – can occur with
placement of a drain
4. pancreatitis – trauma to the tail of
the pancreas
5. deep vein thrombosis – low dose
anticoagulants
B. Hematologic outcomes
1. initial
a. thrombocytopenia – rise in
platelete count within a few days
b. chronic hemolytic anemias –
Hgb level above 10 g/dl
2. long-term
a. 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 spleen’s ability to filter
and phagocytose bacteria and infected
RBC
4. most common sources of infection
a. Streptococcus pneumoniae –
most common
b. Heamophilus influenzae B
c. meninggococcus
d. group A streptococci
5. presents with pneumonia or
meningitis
6. risk factors for the development of
OPSI
a. indication for splenectomy
- hematologic disorder vs trauma
b. overall immune status
c. interval from the date of
surgery – usually within 2 years
7. prevention
a.vaccine against
i. pneumoccocus
ii. H. influenzae
iii. meninggococcus
- to be given within 7-14 days
after splenectomy
b. booster dose for pneumococcal
vaccine every 5-6 years
c. annual influenza vaccine
d. daily dose of penicillin or
amoxycillin for 2 years