Spleen

Moneer Almadani

Diseases Of Spleen

• Splenic Injury

• Immune Thrombocytopenia

• Hereditary Spherocytosis

• Acquired Haemolytic Anaemia

• Hypersplenism

• Left sided portal hypertension

• Proliferative disorders

• Splenectomy

Anatomy

Objectives

• Anatomy & functions
• Causes of splenomegaly
• Splenic diseases of surgical interest
• Indications of splenectomy
• Hematological changes post-splenectomy
• Post-splenectomy sepsis

Surgical Anatomy

A patient after tuma 9,10,11th rib fracture with browses maybe hypotensive

• Convex surface & upper pole:
  • related to diaphragm (9-11 ribs).
• Concave surface:
  • Fundus of stomach, tail of pancreas, & upper pole of left kidney
• Lower pole: rests on splenic flexure of colon

Surgical Anatomy

A presence of spleen

• Accessory spleen:
  • (10-20%)
  • Mostly hilum, may be anywhere
• Splenic artery: branch from celiac axis
• Splenic vein: joins SMV to form portal vein

Surgical Physiology

Highly vascularized (5% CO) - Largest filter of blood & a lymphoid organ - Composed of red & white pulp.

• Red pulp:

  • Made up of sinusoids
  • Filters old RBC
  • Phagocytose
  • Iron transported back to bone marrow for new RBC
  • RBC &Platelets: 1% & 20-30% respectively are sequestrated
  • (Howell-Jolly bodies): Post-splenectomy- mis-shapen RBC with nuclear remnants seen in circulation

• White pulp:

  • largest aggregation of lymphoid tissue
  • Composed of lymphoid follicles (Malpighian bodies), lymphocytes (T & B), macrophages, & plasma cells
  • Site of antigen presentation & antibody production

Immunological function

• Largest aggregation of lymphoid tissues
• Promotion of cell mediated & humoral immunity
• Antigens engulfed by macrophages for antibody production- immunoglobulin (IgM)
• Production of opsonins, properdin from lymphocytes
  • Binds to macrophage & leukocyte
  • Promote phagocytosis and bacteriocidal activity
• Splenectomy impairs immunological responses

Causes of splenomegaly

• Clinically palpable spleen enlarged 3 times
• Infective: TB, abscess, HIV, malaria, schistosomiasis, hydatid cyst
• Blood disease: ITP, Hereditary spherocytosis, autoimmune haemolytic anemia, thalassaemia, sickle cell disease, polycythemia, leukaemia
• Metabolic: Gaucher’s disease, amyloidosis
• Circulatory: Portal hypertension, infarction
• Nonparasitic Cysts: Congenital/ acquired
• Neoplasms: Hodgkin’s, other lymphoma, myelofibrosis, angioma #RR - Class

References

• Principles and Practice of Surgery
  • Pg 229-232