Spleen Flashcards
(142 cards)
1
Q
The most common anomaly of splenic embryology is?
A
the accessory spleen
2
Q
Accessory spleen seen in what % of pts?
A
20%
3
Q
80% of accessory spleens are found where?
A
splenic hilum and vascular pedicle
other areas; gastrocolic ligament, pancreatic tail, greater omentum, stomach greater curvature
4
Q
What organs surround the spleen?
A
greater curvature of stomach
splenic flexture of colon
apex of left kidney
tail of pancreas
5
Q
What ligaments tether the spleen in place?
A
spleno-colic ligament
gastro-splenic ligament
phreno-splenic ligament
spleno-renal ligament
6
Q
Which ligament tethering the spleen contains vessels?
A
gastro-splenic ligament—> short gastrics
spleno-renal ligament–> splenic artery and vein and tail of pancreas
the remaining ligaments are avascular
7
Q
Relationship between spleen and panrceas?
A
tail of pancreas lies within 1 cm of spleen 75% of time
known to abut the spleen in 30% of pts
8
Q
What ribs protect spleen on left?
A
ribs 9, 10, 11
9
Q
Spleen derives it’s blood supply from where?
A
splenic artery
10
Q
Splenic artery can be characterized by the pattern of its terminal branches, which are?
A
magistral (30%)
distributed (70%)
11
Q
What splenic artery branching type most common?
A
distributed–> short trunk with many long branches enter spleen
12
Q
What is the magistral splenic artery pattern?
A
magistral–> long trunk, with few short branches entering spleen
13
Q
Aside from the splenic artery the spleen also receives some its blood supply from?
A
short gastrics in the gastro-splenic ligament
14
Q
What is the venous drainage of the spleen?
A
splenic vein–> joined by the SMV to enter into the portal vein
15
Q
Parenchyma of spleen is made up of two parts:
A
red pulp (75% of splenic volume)
white pulp
16
Q
In the spleen, the red pulp and white pulp interface where?
A
at the narrow marginal zone
17
Q
Function of red pulp?
A
macrophages phagocytize aging RBCs as they try to pass
18
Q
This component of the spleen serves as a filtration system, allowing macrophages to remove microorganisms, cellular debris and aging RBCs;
A
red pulp
19
Q
What is the white pulp of the spleen?
A
at the end of splenic arterioles we have a peri-articular lymphatic sheath made of B cells and T cells
20
Q
Between the white and red pulp we have the marginal zone, what cell types reside there?
A
macrophages
21
Q
White pulp is involved in what type of immunity?
A
adaptive
22
Q
Innate immune function of spleen occurs via?
A
marginal zone macrophages
23
Q
The spleen acts as major site of clearance for what?
A
aging RBCs
24
Q
Of a RBCs 120 days life cycle, how much of that time do they spend in the spleen?
A
2 days
spleen removes 20 cc of aging RBCs from circulation
25
What 3 things does the spleen produce?
opsonins
tuftins
properidin
26
What splenic product initiates alternate pathway of complement activation:
properidin
27
Splenomegaly vs hypersplenism:
splenomegaly--> abnormal enlargement of spleen
hypersplenism--> presence of one or more ctyopenias in context of normal functioning bone marrow
28
Half life of a neutrophil vs platelet?
neutrophil--> 6 hrs
platelet---> 10 days
29
OPSI is commonly caused by encapsulated organisms such as:
strep pneumo
h. flu
neissieria meningitidis
30
What causes hereditary spherocytosis?
deficiency/dysfunction in one of the erythrocyte membrane proteins; spectrin, ankyrin, band 3 protein
31
This is an inherited disorder where we have dysfunction of one of the erythrocyte membrane proteins like spectrin and ankyrin;
hereditary spherocytosis
32
WHat happens to RBCs in hereditary spherocytosis?
bilipid membrane layer is destabilized, get pathological release of membrane lipids
RBC becomes spherical, less deformable, gets trapped in spleen and destroyed
33
This is an AD dx affecting spectrin, a RBC cytoskeleton protein;
hereditary spherocytosis
34
Inheritance patterns of hereditary sphercytosis?
AD
35
What are some clinical findings and lab values we see with hereditary spherocytosis?
mild jaundice
splenomegaly on exam
varying degrees of anemia
spherocytes seen on blood smear
36
Why is cholecystectomy performed for hereditary spherocytosis?
pts have increased risk of pigmented stone formation due to destruction of RBCs
37
Most common hemolytic anemia for which splenectomy is indicated?
HS
38
When do we remove the spleen in someone with hereditary spherocytosis?
symptomatic hemolytic anemia
growth retardation
skeletal changes
extramedullary hematopoietic tumors in young pts
39
If gallstones co-exist with hereditary spherocytosis what do we do?
splenectomy + cholecystectomy
**prophylactic cholecystectomy is not indicated
40
When performing splenectomies in children affected by HS, at what age do we perform it?
by age 5
41
Why do we wait to perform splenectomies for HS in children until age 5?
preserve immune fx of spleen
reduce risk of OPSI
42
What are the two hereditary conditions assc with hemolytic anemias?
pyruvate kinase deficiency
| G6P dehydrogenase deficiency
43
This d/o is is an AR disease that results in decreased RBC deformability and the formation of echinocytes:
PK deficiency
44
This is the most common RBC enzyme deficiency;
PK deficiency
45
FOr which inherited enzyme deficiency d/o is splenectomy indicated?
PK deficiency
46
Primary treatment for G6P deficiency?
NOT splenectomy
avoid foods, drugs that can precipitate a crisis
47
This is an X-linked inherited d/o affecting more people worldwide that PK deficiency;
G6P deficiency
48
Primary treatment of G6P deficiency?
void foods, chemicals, drugs that exacerbate hemolytic episodes
most pts have mild to mod sxs
49
THis is an autoimmune d/o characterized by low platelet count, mucocutaneous and petechiae bleeding;
ITP
50
What causes the low platelets seen in ITP:
premature removal of platelets opsonized by anti-platelet IGG made by the spleen
51
Typical presentation of ITP includes?
```
purpura
epistaxis
gingival bleeding
(less common; gi bleeding, hematuria)
(rare but fatal; intracranial bleeding)
```
52
Diagnosis of ITP involves what?
exclusion of other causes of thrombocytopenia
53
Incidence of major intracranial bleeding from ITP?
1%
54
Difference in presentation of ITP in children vs adults?
children; often present at young age, with sudden onset of petechiae, purpura days/weeks after an infectious process
adults; have a more chronic form of dx, with insidious onset
55
How common is splenomegaly with ITP?
uncommon
56
ITP predominantly affects men or women?
young women
57
First line therapy for ITP?
oral predinose 1.0 mg/kg/day
most responses occur with first 3 weeks
58
When do we give IVIG for ITP?
usually for internal bleeding, in pregnant pts, pts being prepped pre-op
59
Dose of IVIG for ITP?
1g/kg for 2-3 days
60
When do we perform splenectomies for ITP?
pts with plts <10K for 6 weeks or longer
thrombocytopenia refractory to steroid therapy
pts who require toxic steroid doses for remission
61
How is sickle cell disease inherited?
autosomal co-dominant
pts can be carriers who inherit one abnormal gene from one parent (heterozygous)
pts can have the disease if they inherit two abnormal genes (homozygous)
62
What causes sickle cell dx?
mutated adenine to thymine in 6th codon of B-globin gene
valine substituted for glutamic acid
63
Valine substituted for what in sickle cell dx?
glutamic acid
64
Common reasons for splenectomy in pts with sickle cell dx?
recurrent sequestration crises
hypersplenism
splenic abscess
65
What medication can we use in sickle cell dx?
hydroxyurea
66
How does hydroxyurea work for sickle cell dx?
upregulates fetal Hgb
67
What is a target cell?
RBC with nucleus in tact
68
This d/o characterized by thrombocytopenia, microangiopathic hemolytic anemia and neurological disorders;
TTP
69
What causes TTP?
large multimers of VW factor assc. with platelet clumping in pt's blood
70
What are the clinical features of TTP?
```
petechiae
fevers
neuro sx
renal sx
cardiac sx
```
71
The diagnosis of TTP is confirmed by blood smear, which shows what?
schistocytes
nucleated RBCs
basophilic stippling
72
Tx for TTP?
plasma exchange is first line
splenectomy for pts who relapse or require multiple exchanges
73
Where do we find accessory spleens commonly?
hilum 54%
pedicle 25%
greater omentum 12%
tail of pancreas 6%
74
What is Hodkin's dx?
malignant lymphoma affects adults in their 20's 30s
75
How do pts with Hodkin's dx typically present?
cervical lymphadenopathy
rarely present with constitutional sxs
76
What are the different types of Hodkin's dx?
lymphocyte predominant
nodular sclerosing
mixed cellularity
lymphocyte depleted
77
How do we classify Hodkin's dx?
Ann Arbor classification system
78
What's the Ann Arbor classification system of Hodkin's dx?
Stage 1 --> single lymphatic site
Stage 2--> 2 or more lymphatic sites on same side of diaphragm
Stage 3--> disease on both sides of the diaphragm w/splenic involvement
Stage 4--> disease disseminated into extralymphatic sites like liver, lung, bone marrow
79
Most common primary splenic neoplasm?
NHL
80
Hairy cell leukemia is a rare disorder, characterized by what?
splenomegaly
pancytopenia
neoplastic mononuclear cells in the peripheral blood
81
What chromosomal marker associated with CML?
philadelphia chromosome; 9;22
82
Chromosome 9 and 22 fuse, causing expression of a bcr/abl gene product, a tyrosine kinase which accelarates cell division and impairs DNA repair, this is seen in what?
CML
83
Chromosome seen in CML, coding for bcr/abl tyrosine kinase?
9;22
84
Solid tumors that most frequently spread to the spleen?
breast
lung
melanoma
85
Angiosarcomas of the spleen have been linked to what environment exposures?
vinyl chloride
| thorium dioxide
86
How do we classify splenic cysts?
true cysts (can be parasitic vs non-parasitic)
pseudocysts
87
True cysts of spleen are lined with a squamoues epithelium and stain for what 2 markers?
CEA
| CA 19-9
88
Primary true cysts of spleen make up what %?
10% of all non-parasitic splenic cysts
89
Most non-parasitic splenic cysts are?
pseudocysts due to trauma
90
Are true splenic cysts malignant?
benign
91
Operative intervention for splenic cysts?
indicated for pts with symptoms and those w/large cysts
92
When performing partial splenectomies for symptomatic or large cysts, what % of spleen remnant needed to protect against pneumococcal pneumonia?
25%
93
Most true splenic parasitic cysts and occur in endemic areas such as:
Echinococcus species
94
What do we see on imaging of splenic cysts suspected to be echinococcal?
cyst wall calcificatons
| daughter cysts
95
What do we worry about with parasitic splenic cysts?
rupture into abdomen
| spillage of cyst contents and an anaphylactic rxn
96
Tx of choice for parasitic cysts?
splenectomy
97
Other tx for parasitic cysts beside splenectomy?
inject cyst with 3% NS
alcohol or silver nitrate
avoid rupture intra-op
98
What makes a pseudocyst of the spleen a pseudocyst?
not lined by epithelium
99
These makes up 70-80% of non-parasitic splenic cysts:
pseudocysts due to trauma
100
What is the size cutoff for pseudocysts treatment?
asymptomatic <4 cm cysts involve with time
101
Mortality rates of splenic abscesses?
15-20% in healthy pts
80% in immunocompromised pts
102
70% of splenic abscesses are due to hematogenous spread from?
endocarditis
osteomyelitis
IV drug use
103
How do we diagnose splenic abscesses?
CT
104
Tx of splenic abscess depends on what?
whether it's unilocular or multilocular
105
1/3 of adult pts, splenic abscess tend to be what?
multilocular
106
1/3 of children pts, splenic abscces tend to be what?
unilocular
107
What is the tx for unilocular vs multilocular splenic abscesses?
unilocular---> percutaneous drainage + abx
multilocular--> splenectomy, drainage of LUQ, abx
108
How common are splenic abscesses?
uncommon
0.14--0.7%
109
Infectious mononucleosis due to EBV or CMV imparts a small risk of?
splenic rupture
splenic parenchyma infiltrated by inflammatory cells--> thins the capsule
rupture can occur after minor trauma
110
Common organisms isolated from splenic abscesses?
streptococci and e.coli **MC
others; mycobacteria tb, salmonella
111
MCC of splenic cysts worlwide?
parasites like echinococcus
112
SPlenic cysts resulting from trauma are called?
pseudocysts
113
What Ca most commonly spreads to spleen?
lung
114
In terms of splenic artery aneurysm who is more affected men or women?
women 4;1
115
In what part of splenic artery do we commonly seen splenic artery anuerysm?
mid to distal
116
When do we treat splenic artery aneurysms?
presence of sxs
pregnancy
intent to get pregnant
117
Tx for splenic artery aneurysms?
aneurysms in mid portion-->resection or ligation
distal portion--> need splenectomy
118
Rheumatoid arthritis, neutropenia, splenomegaly make up what ?
Felty syndrome
119
Preferred method of splenectomy?
laparoscopic
| barring trauma and massive splenomegaly
120
Disadvantage of laparoscopic splenectomy?
longer op times
| difficult removing large organs
121
When do we give vaccines prior to elective splenectomies?
2 weeks prior
122
Most common fatal late complication of splenectomy?
OPSI
123
After splenectomies when do we see OPSI?
most occurred after 2 yrs
| 42% occurred after 5 yrs
124
OPSI as a result of dog bites due to what bacteria?
capnocytophaga canimorsus
125
OPSI is greatest in pts who have had splenectomies for what?
hematologic disorders rather than trauma
126
For post-splenectomy pts when do we give vaccines?
within 2 weeks of splenectomy if pt did not receive before surgery
127
What vaccines do we give in splenectomized pts?
PPV23 (polyvalent pneumococcal vaccine)
h flu type B conjugate
meningococcal polysaccharide vaccine
128
OPSI is more common children or adults?
adults
risk greatest within first 2 yrs
129
What bacteria responsible for >50% of OPSI?
s. pneumo
130
For emergent splenectomy cases why do we wait 2 weeks to vaccinate pts post-op?
transient immunosuppressions assc w/surgery
131
What is the overall incidence of OPSI?
<1 %
132
Most common method of intra-op splenic injuries?
improper splenic traction against its peritoneal attachments
causes capsular tears
lower pole more commonly injured to greater peritoneal attachments in lower pole
133
What causes OPSI in splenectomized pts?
loss of splenic macrophages
diminished tuftsin production
loss of spleens reticuloendothelial system
*** in normal pts, these three things work together to opsonize bacteria from bloodstream
134
Most common complication after open splenectomy?
left lower lobe atelectasis
135
Most common indication for open splenectomy?
trauma
136
Incision for open splenectomy?
left subcostal incision along left costal margin
2 fingerbreadths below
midline incision preferred when spleen ruptured or massive
137
In splenectomies how do we gain access to lesser sac?
free up the gastro-splenic ligament
138
WHere do we find the splenic artery?
superior border of pancreas
139
When doing splenectomies for enlarged spleen why ligate splenic artery first?
easier to mobilize spleen
easier to dissect hilum
allows spleen to shrink a bit
allows for transfusion of RBCs and platelets
140
After open splenectomy do we leave a splenic drain in place?
not routinely done
**risk of subphrenic abscess
141
How do we mobilize the spleen in open splenectomies?
mobilize the spleno-colic ligament first
mobilize spleno-phrenic ligament
mobilize and ligate short gastrics
dissect hilum, ligate artery then vein
142
Gold standard approach to splenectomy in pts with normal sized spleens?
laparoscopic
