Spleen : Haematological
DEFINITION
Discusses splenectomy for haematological disorders.
Generally a symptomatic procedure; rarely leads to a cure.
Notes: a normal spleen is 11cm. Moderate splenomegaly is
11cm-20cm. Massive is >20cm
D E A B M I M
EPIDEMIOLOGY
Not addressed.
D E A B M I M
AETIOLOGY
Classification of Possible Indications for Splenectomy
Autoimmune /
idiopathic
- idiopathic thrombocytopaenic purpura (ITP)
- thrombotic thrombocytopaenic purpura (TTP)
- idiopathic autoimmune haemolytic anaemia
- felty syndrome
- sarcoidosis
Genetic
deficiencies
- Thalassemia
- Sickle cell anaemia
- Gaucher disease
- Pyruvate kinase deficiency
- G6PD deficiency
- Amyloidosis
Red blood cell
disorders
- Hereditary spherocytosis
- Hereditary elliptocytosis
- Hereditary pyropoikilocytosis
- Hereditary stomatocytosis
- Hereditary xerocytosis
White blood
cell disorders
- Hodgkin lymphoma
- Non-Hodgkin lymphoma
- Chronic lymphocytic leukaemia
- Chronic myelogeneous leukaemia
- Hairy cell leukaemia
Bone marrow
disorders
- Primary myelofibrosis
- Myeloproliferative disorders
D E A B M I M
BIOLOGICAL BEHAVIOUR
Brief Biology of More Common Indications
Autoimmune / idiopathic
Idiopathic
thrombocytopaenic purpura (ITP)
Spleen produces an IgG that binds to platelets
--> Platelets are then cleared by phagocytes, mainly in spleen
and liver.
--> Thrombocytopaenia, petechiae, purpura, ecchymosis, mucosal
bleeding, risk of intracranial haemorrhage if platelets <20
--> F:M 3:1, but also children (us. self-limiting).
Spleen is of normal size.
Megakaryocytes on marrow biopsy.
Can be secondary to HIV, SLE, antiphospholipid antibody syndrome,
hep C, lymphoproliferative disorders
- or drugs (cocaine, gold, antibiotics, heparin, qunidine,
abciximab, anti-inflammatories).
Physicians will treat when platelets 20-30 thousand / mm3 or <50
with significant symptoms
- high-dose prednisone (4 mg/kg/day) and IV immunoglobulin Rx are
cornerstones to therapy
- response rate is high but
relapse common.
Splenectomy indication:
Failure of medical therapy (6-8 wk after steroids)
Persistent ITP >1yr
Severe thrombocytopaenia.
--> Response within a week; 75-85% permenant.
Thrombotic
thrombocytopaenic purpura (TTP)
Rare. Endothelium-triggered platelet deposition in arterioles and
capillaries.
--> micro-vascular thrombotic episodes.
- microangiopathic haemolytic anaemia, severe thrombocytopaenia,
fever,
- organ failure: renal, cardiac failure and dysrhythmia.
- headache, mental state changes, seizures, coma,
May follow clopidogrel usage
Blood film shows schistocytes, nucleated red blood cells and
basophilic stippling.
Physicians will treat with daily plasmaphoresis and FFP
transfusions. High dose steroids can limit recurrences.
--> high response rate.
- not platelets as risk deterioration of pathology
Splenectomy indication:
Frequent relapses.
--> Response rate only <50%
Autoimmune Haemolytic
Anaemia (AIHA)
Autoantibodies formed and directed against RBC antigens.
--> anaemia, RBC sequestration
Idiopathic or related to infection, SLE, leukaemia
Can be warm or cold
- warm: IgG auto-antibodies optimally act at body temp; blood smear
and direct antiglobulin test will show
- cold: less common 25%; autoantibodieas act at 5o; post-infection
eg EBV, or in lymphoproliferative disorders; must avoid cold or get
acute haemolytic crises.
Physicians treat with"
- warm: steroids (1-2mg/kg/day) with good response in 60%;
- cold: plasmaphoresis, alkylating agents, not steroids
Splenectomy indication:
Warm AIHA only.
- never cold as spleen not the problem there.
No remission in 3 weeks
Hb conc not maintained by steroids.
--> Most improve within 2 weeks; 50% will need ongoing steroids.
Felty Syndrome
Rheumatoid arthritis, neutropaenia, splenomegaly.
85% have HLA-DR4 antigen.
Severe or chronic infections due to neutropeania; counts
<0.5x10^9
Rx methotrexate, DMARDS, G-CSF
Splenomegaly is variable
Splenectomy indication
Failure of medical therapy: recurrent infections or severe
neutropaenia
80% haematological response rate
Sarcoidosis
Noncaseating granulomatous disease
Splenic involvement usually part of systemic disease
- 40% of sarcoid pts have splenomegaly; 3% massive.
- true splenic involvement with sarcoid only 10-15%
Treatment is with steroids or methotrexate
Splenectomy indication:
Symptoms from splenomegaly; sequestration, pain, ?tumours
Splenectomy does not alter course
- but can improve refractory hypercalcaemia
Red Blood Cell Disorders
1. Hereditary spherocytosis
AD inherited most common RBC disorder; fragile cells, get lodged in
splenic pulp and destroyed
Range from asymptomatic, mild jaundice to jaundice, splenomegaly and
pigment stones
- 50% develop stones after 5y
Splenectomy
Most common indication in anaemia; also cholecystectomy if
gallstones.
Is curative in almost all patients.
Usually delayed til >5y old to limit OPSI
Controversy as to operating on pts wiht milder forms of disease
- some studies advocate partial splenectomy.
2. Hereditary elliptocytosis
Similar story but less common; biconcave ellipocytes
Less severe clinical course but less severe as more deformable cells
in most forms.
May need splenectomy for severe haemolysis and it is curative.
3. Hereditary pyropoikilocytosis
AD disease of red cell membrane defects.
Usually presents young with severe jaundice / anaemia
Splenectomy is curative
4. Hereditary stomatocytosis and xerocytosis
Rare disorders, variable course; range from symptomatic to mild
anaemia.
Increased cation permeability, leading to high cell volume.
Splenectomy may improve anaemia but does not fully correct
haemolysis.
- anyway most are mild and don't need it.
Genetic syndromes
1. Thalassemia
AD disorders, of Hb chains.
Most common genetic disorder in the world.
Beta more common.
Heterozygous form (minor) usually asymptomatic but with microcytosis
and mild anaemia.
Major is much more severe
- severe haemolytic anaemia as babies and complications of that.
Periodic lifelong blood transfusions and iron chelation.
High transfusion requirement may necessitate splenectomy to maintain
cells.
- usually delayed until 4-5y old to limit OPSI
Marrow transplantation considered but most major pts die in <30y
due to cardiac sequelae.
2. Sickle cell anaemia
AR haemoglobinopathy.
HgS propensity to deform and sickle-shpaes when in low-O2 tension.
Cause stasis and vasoocclusion in microvasculature
--> tissue ischaemia, severe pain and chronic organ damage;
sickle cell crises.
Homozygotes autosplenectomy from multiple infarcts at young age.
Thus splenectomy rarely indicated; except splenic abscess.
3. Gaucher disease
Glycolipid stoage disease with deposition of glucocerebrosdie in
reticuloendothelial system.
May get massive hepatosplenomegaly and splenectomy indicated with
refractory cytopaenia.
4. Pyruvate kinase deficiency
Most common genetic defect causing hemolytic anaemia; AR disease
Results in ATP deficiency
- rbcs poorly deformable; destroyed
Hemolysis is exacerbated by acute infections and pregnancy.
5. Amyloidosis
Exceallular deposition if insoluble proteins; hepatosplenomegaly in
25%, severe splenomegaly in 10%
Splenectomy if functionally indicated.
White blood
cell disorders
1. Hodgkin lymphoma
Lymphoreticular cell neoplasm, young adults in 2nd-3rd decades
Historically splenectomy was done for staging, now rarely needed
unless thrombotypenia
2. Non-Hodgkin lymphoma
Most common lymphoma; diverse group with prognosis based on
histologic type and features.
Splenic involvement in ~70%
Splenectomy if anemia, massive spleen and cytopaenia /
sequestration.
Some types more likely to involve spleen;
- splenic marginal zone lymphoma = indolent B-cell neoplasm in older
pts;
- first line Rx is splenectomy, leads to partial remission in many
pts and complete remission in some.
3. Chronic lymphocytic leukaemia
B cell leukaemia, progressive accumulation of functionally
incompetent lymphocytes.
Oder pts; splenic infiltration is common and can be severe
splenomegaly and cytopaenia
Splenectomy can relieve symptoms and cytopaenia
- considered if refractory to medical therapies.
4. Chronic myelogeneous leukaemia
CML = abnormal proliferation and accumulation of granulocytes.
95% have the classic Philadelphia chromosome; reciprocal
translocations.
Diagnosis during chronic phase (asymptomatic), often get
splenomegaly
Can accelerate with fevers, increased WCC abnd splenomegaly.
Imatinib
5. Hairy cell leukaemia
Rare; B cells with proections
Indolent disease presents with splenomegaly, pancytopenia
(hypersplenism)
Splenectomy used to be required routinely; chemotherapy improvements
mean it is now rarely needed.
- note occasionally these WBC tumours can rupture, bleed
spontaenously though
Bone marrow disorders
1. Primary myelofibrosis
Chronic malignant hematological disorder (abnormal myeloid
precursors)
- leads to medullary fibrosis and extramedullary haematopoiesis
Splenomegaly can be massive with sequestration (and portal htn from
venous thrombosis).
Splenectomy if thrombocytosis, hemolysis requiring transfusions,
pain, infarctions, htn with ascietes.
High morbidity and mortality and highly selective.
2. Myeloproliferative disorders
Collection of disorders of abnormal proliferation of
erythroid, megakaryocytic or granulcytic myeeloid cells.
- beginning in marrow then extramedullary.
Splenomegaly can be massive
Splectomy can provide useful palliative treatment.
D E A B M I M
MANIFESTATIONS
As above
D E A B M I M
INVESTIGATIONS
As above
D E A B M I M
MANAGEMENT
Pre-Op Considerations
1. Imaging is crucial for planning (ie CT)
- Anatomic location, relationships, size, etc.
2. Preop splenic artery embolization can be considered in portal htn
- can make lap surgery more manageable.
3. If platelet transfusion is reqd peri-operatively (platelets
<10) or bleeding
--> hold transfusion until
splenic artery ligated.
4. Preop antibiotics 50min prior to incision should cover flora.
5. Oro / nasogastric to decrease gastric distension
- better visualisation of short gastrics.
6. If steroids are needed, stress-doses given with a rapid taper
post-op.
7. Vaccinate pre-op in elective cases 2 weeks prior to splenectomy
- H influenzae B, polyvalent pneumococcus, Meningococcus
- if emergency, vaccinate post-op
Operative Considerations
1. Either midline laparotomy or L subcostal.
- better midline if massive.
2. Ligate hilum
- either first or after mobilizing the spleen from splenophrenic,
splenorenal and splenocolic attachements.
- consider prioritising if need for platelets, massive, malignancy,
or dense adhesions.
--> enter lesser sac and identify vessels at hilum, gaining
control and avoiding tail of the pancreas.
3. Hilar vessels taken individually
- 'prevents AV fistula' but that is probably extremely rare
- suture ligatures or linear stapling device (in massive spleens =
useful)
4. Spleogastric ligament divided and short gastric vessels
identified and suture ligated or clipped.
- EndoGIA for hilar vessels and ligasure for short gastrics in lap
splenectomy.
5. Once removed, carefully inspect for accessory splenic tissue
- 10-30%; common locations should be checked
- ie, anywhere along the splenic vessles: gastrosplenic ligament,
spenorenal ligament, retroperitoneally, in mesentery, omentum and
occasionally in gonads or path of descent.
- (spleen forms near uorgenital ridge from which gonads develop;
gonads may pull some splenic tissue down with them.
Patients with accessory spleens will lack old cells (howell-jolley
bodies, heinz bodies, target cells, may require reexploration).
Post-Operative Considerations
Monitor for haemorrhage, atelectasis, infection.
Know that pts will usually have an increase in leukocytes post-op;
physiologic.
Infections complications include suphrenic abscess and OPSI.
Give vacc's 2w post op if did not get pre-op
- if compliance a concern then give prior to d/c
- if immunocompromised, wait 3m
Other complications include pneumonia, thyrombocytosis, pleural
effusions, pancreatitis, pancreatic fistula, injury to adjcent
organs.
- higher risk in haematological / immunosuprression.
Thrombocytosis can occure immediately post-op but peaks up to
3weeks.
- antiplatelets only indicated for complications or when platelet
counts hit 1 million.
- portal or mesenteric vein thrombosis is serious, reported in up to
14%, some studies reporting a higher rate in lap spleens.
--> higher risk in myeloproliferative disorders, hemolytic
anemias, long splenic vein stumps, post-op thrombocytosis,
hypercoagulable states and splenomegaly.
--> if treated quickly with systemic anticoagulation, then
recannulation rates can be >90%.
D E A B M I M
REFERENCES
Cameron 10th