eMentorSurgery

      Dear students, This is only for your revision and NOT A FULL TEXT.                             

Spleen

(ANATOMY,FUNCTIONS,RUPTURE&HYPERSPLEENISM)                                                                                                                                

ANATOMY

Largest lymphoid organ, located on the leftside of the abdominal cavity beneath the diaphragm

Devoleped from left side of the dorsalmesogastrium in the 8-mm embryo.

--shaped like a segment of an orange.

--lies between the tenth and eleventh ribsposteriorly.

--diaphragm superiorly.

--Transverse colon-Inferiorly

--gastric impression-Anterirly.

--Kidney-Posteriorly.

-- hilum - the tail of the pancreas and thesplenic vessels.

-- the short gastrics pass to the greater curve of the fundus of thestomach.

Structureof the Spleen 

Surrounded by a fibrous capsule, ithas trabeculae that extend inwards.

 Functions of the spleen

1.       production. The nonspecificopsonins tuftin and properdin are synthesised.

2.       .Filter Immune function—immunoglobin M (1gM) function —macrophages pneumococci.

   3 •Removal of effete, platelets and red cells —this process is called‘culling’.

   4• Pitting —removing particulate inclu­sionsfrom red cells and returning the repaired red cell to the circulation.

malarial parasitescan be removed by this process without destroying the cell.

  5•Iron reutilisation —

     return the iron to the plasma.

  6•Pooling — up to 30—40 per cent of bloodplatelets are sequestered within the spleen.       platelet destruc­tion,

-thrombocytopenia.

   7•Reservoir function —in animals,

       -not occur in humans.

   8.Haematopoiesis—occurs up to the fifthintra­uterine month and thereafter in certain disease states.

* Rupture of thespleen

-trauma,-

direct injury tothe left upper quadrant of the abdomen from any angle.

-fall

-if it is diseasedor enlarged, for example in infectious mononucleosis or malaria.

-by digging avictim beneath the left ribs with a weapon known as the ‘larang’;

-the enlargedmalarial spleen would rupture.

-suspected ifthere are fractures of the overlying ribs.-

-Iatrogenic-,especially if adhesions

Cases of rupturedspleen may be divided into three groups.(3)

     1•The patient succumbs rapidly frommassive haemorrhage —rare.

     2•Initial shock, recovery and signs ofbleeding —the initial shock is due to the blood loss, tamponade occurs and thenfurther bleeding takes place..

 Kehr’ssign.- Pain referred to theleft shoulder

Ballance’sign- persistant dullness on left side ofabdomen due to coagulated spleenic ruptured blood.

-Shifting dullnessmay be present in the flanks and on rectal examination fullness in the pelvisis present.

-ultrasonographyor

-CT scanning to determine the site from which thebleeding is occurring.

 3• The delayed case —after initial signshave

passed off and theconcern about a serious occurring.

-laparotomy or, atthe minimum, close observation.

- ultrasonography

--plain X-ray ofthe abdomen

the followingsigns can be elicited:

—    obliteration of the spleenic outline;

—    obliteration of the psoas shadow;

—    indentation of the left side of the gastric   air bubble;

—    fractureof one or more lower ribs of the left side;

—    elevationof the left hemidiaphragm;

      -free fluid between gas-filled intestinalcoils.

-      Downward displacement of spleenic flexure.

Treatment

--laparotomy

-splenectomy,-where malaria is common,

 --splenic preservation should be undertakenwhere possible.

-careful compressionof the spleen the bleeding can be con­trolled a vicryl mesh bag can beconstructed and the spleen placed in the bag which is then tightened tocompress the spleen and to stop the bleeding.

-invaluable inchildren who are most at risk from splenectomy.

Splenomegaly and HypersplenismPresentation Left upper quadrant (LUQ) mass or "uncomfortable"abdominal pain, early satiety from compressed stomach. Pancytopenia due to hypersplenism(see below).

Examination When considering whether a LUQ mass is an enlarged spleen,remember the spleen

Moves with respiration. Enlarges towards the right iliac fossa (RIF) - always start palpation in the RIF and move across towards the RUQ or you may miss massive splenomegaly! You cannot palpate above it - upper margin lies under the ribs. You may feel a notch. It is dull to percussion. Always remember to check for anyaccompanying lymphadenopathy and/or features of liver disease.

Investigations Abdominal USS, MRI and CT. FBC, ESR, LFT ± liver, marrow, orlymph node biopsy. Radioisotope liver and spleen scan.

Aetiology

Haematological

Infections

Tumours and Cysts

Haemolytic anaemias (eg Thalassaemia, Red cell defects,

Sickle cell anaemia) Acute Leukaemias Chronic leukaemias (CML, CLL) Polycythaemia Rubra Vera Macroglobulinaemia Lymphoma (Hodgkin's and NHL) Essential thrombocythaemia Myelofibrosis Malaria Schistosomiasis Visceral leishmaniasis

(Kala-azar) Tuberculosis Glandular Fever Subacute bacterial endocarditis Splenic Abscesses Splenic Metastases Cysts (eg Hydatid, Dermoid) Tumours (eg Haemangioma) Congestive splenomegaly

Connective Tissue Disorders

Other Disorders

Liver Cirrhosis Budd Chiari Syndrome Portal or Splenic vein obstruction Cardiac Failure Systemic Lupus Erythematosus Felty's Syndrome Gaucher's Disease Niemann Pick Disease Histiocytosis X Amyloidosis

Causes of massivesplenomegaly CML, myelofibrosis, malaria(hyper-reactive malarial splenomegaly), leishmaniasis, 'tropical splenomegaly'(idiopathic - Africa, SE Asia), and Gaucher'ssyndrome.

Splenomegaly in children is most commonly caused by infection, autoimmune disorders orhaemolysis. It may be a presenting feature of neoplasia (eg metastaticneuroblastoma). Causes include:

Infection: Glandular fever, CMV, other viral infections, often accompanied by lymphadenopathy, bacterial, protozoal, and fungal infections. Autoimmune:juvenile rheumatoid arthritis Haemolysis: hereditary spherocytosis, sickle cell anaemia, Thalassaemia Neoplasia: ALL, Hodgkin disease and NHL, acute or chronic myeloblastic leukemia, neuroblastoma. Inherited diseases: Gaucher's disease and other storage disorders. Hypersplenism This is a pancytopenia occurring inpatients an enlarged spleen - due to large numbers of cells being pooled anddestroyed in the spleen's reticuloendothelial system, and haemodilution becauseof an increased plasma volume. It can present with symptoms of anaemia,infection, or bleeding. Bone marrow biopsy shows normal or hyperplastic marrow.Splenic sequestration crisis may develop in young children with sickle cellanaemia, which can precipitate hypovolaemic shock and death, and is anindication for splenectomy.

Management Treat cause. Open or laparoscopicsplenectomy may be indicated to control or stage the disease (eg hereditaryspherocytosis, Hodgkin's disease).

Patients with impaired splenicfunction need prophylactic vaccinations etc -