---

Spleen Disorders - Surgery

---

1. Surgical Anatomy

• Splenic artery - longest, most tortuous branch of celiac artery
  • Distributed type (70%): short trunk, many long branches entering >3/4 of medial surface
  • Magistral type (30%): long main trunk dividing near hilum into short terminal branches
• Additional supply from short gastric vessels (via gastrosplenic ligament)
• Splenic vein joins superior mesenteric vein to form portal vein

---

2. Functions of the Spleen

1. Filtration - macrophages in red pulp remove aged erythrocytes, microorganisms, antigen-antibody complexes
2. Immunity - produces IgM, opsonins (tuftsin, properdin), alternative complement pathway activation
3. Hematopoiesis - extramedullary in pathologic states
4. Reservoir - stores platelets and RBCs
5. Phagocytosis - especially effective against poorly opsonized encapsulated bacteria (Pneumococcus, H. influenzae, Meningococcus)

---

3. Splenomegaly vs. Hypersplenism

• Congestive: Portal hypertension (cirrhosis, splenic/portal vein thrombosis)
• Hematologic: Hemolytic anemias, thalassemia, sickle cell disease, ITP
• Infectious: Malaria (most common cause worldwide), EBV (infectious mononucleosis), TB, bacterial endocarditis
• Infiltrative/Storage: Gaucher's disease, amyloidosis, hemochromatosis
• Neoplastic: Lymphoma, leukemia (CML - found in ~50% of patients), myelofibrosis
• Autoimmune: Rheumatoid arthritis (Felty syndrome), SLE

---

4. Splenic Trauma

Grading (AAST Splenic Injury Scale)

Management Algorithm

• Hemodynamically unstable - immediate laparotomy and splenectomy
• Contained pseudoaneurysm - angiography + selective embolization
• Relative contraindications for NOM (age >55, severe TBI, aorta transection, subcapsular hematoma) - consider early splenectomy
• Contrast blush on CT - angioembolization
• Otherwise stable - non-operative management (NOM), repeat CT at 6-8 weeks

---

5. Red Blood Cell Disorders & Hemoglobinopathies

Hereditary Spherocytosis

• Autosomal dominant defect in spectrin (red cell cytoskeletal protein)
• RBCs are spherical, rigid, trapped in splenic cords and destroyed
• Features: hemolytic anemia, jaundice, splenomegaly, gallstones
• Blood smear: spherocytes, increased osmotic fragility
• Splenectomy is curative - resolves anemia but does not correct the RBC defect
• Delayed until >4 years of age (immune maturity)

Thalassemia

• Inherited disorder of hemoglobin chain synthesis (most common single-gene genetic disease)
• Most prevalent in "thalassemia belt" (Mediterranean, Middle East, India, Southeast Asia)
• β-thalassemia major presents at 4-6 months (pallor, growth retardation, jaundice, hepatosplenomegaly)
• α-thalassemia symptomatic in utero or at birth
• Treatment: RBC transfusions (Hb >9 g/dL) + deferoxamine chelation
• Splenectomy indicated when:
  • Transfusion requirement >200 mL/kg/year
  • Symptomatic splenomegaly
  • Painful splenic infarction
• Risk: pulmonary hypertension post-splenectomy; high rate of OPSI due to coexisting iron-overload immune deficiency

Sickle Cell Disease

• RBCs contain HbS - sickle in low-oxygen states
• Functional asplenia by age 5-6 due to repeated infarction (autosplenectomy)
• Acute splenic sequestration crisis: sudden trapping of RBCs in spleen, acute massive splenomegaly, life-threatening - treated with transfusion; splenectomy for recurrence

Autoimmune Hemolytic Anemia (AIHA)

• Warm-type (IgG): splenectomy beneficial; ~60-80% response rate
• Cold-type (IgM): splenectomy less effective

---

6. Platelet Disorders

Idiopathic (Immune) Thrombocytopenic Purpura (ITP)

• Pathophysiology: IgG autoantibodies coat platelets → splenic macrophages destroy platelets + spleen produces anti-platelet antibodies
• Clinical: mucocutaneous bleeding, petechiae, platelet count <100,000/µL (often <20,000)
• Acute ITP: children, follows viral illness, self-limiting (90% resolve spontaneously)
• Chronic ITP: adults (female predominance), persists >6 months

1. Corticosteroids (first line) - 60-80% initial response
2. IV immunoglobulin (IVIG) - rapid but temporary
3. Anti-D immunoglobulin (Rh+ patients)
4. Splenectomy - indicated for failure of medical therapy after 6 weeks, or platelet count <10,000 with severe bleeding
   • Response rate: ~80-85% (complete + partial)
   • Predictors of response: age <45, short disease duration, good initial steroid response
5. Rituximab, thrombopoietin receptor agonists (eltrombopag, romiplostim) - second-line medical
6. Danazol, azathioprine - third-line

---

7. White Blood Cell / Lymphoma Disorders

Lymphoma

• Both Hodgkin's and Non-Hodgkin's lymphoma commonly involve the spleen
• Indications for splenectomy in lymphoma:
  • Symptomatic massive splenomegaly
  • Hypersplenism causing cytopenias prohibiting chemotherapy
  • Diagnostic staging (now largely replaced by PET-CT)

Hairy Cell Leukemia (HCL)

• Chronic B-cell lymphoproliferative disorder
• Classic triad: pancytopenia, massive splenomegaly, circulating "hairy" cells on blood smear
• TRAP (tartrate-resistant acid phosphatase) stain positive
• First-line treatment: cladribine (2-CDA) or pentostatin
• Splenectomy provides temporary hematologic improvement but cladribine is now preferred

Chronic Lymphocytic Leukemia (CLL)

• Most common leukemia in adults (Western world)
• Splenectomy indicated for symptomatic splenomegaly + hypersplenism causing cytopenia

---

8. Bone Marrow (Myeloproliferative) Disorders

Chronic Myelogenous Leukemia (CML)

• t(9;22) - Philadelphia chromosome (bcr-abl fusion)
• Splenomegaly in ~50% of patients
• Treatment: imatinib (tyrosine kinase inhibitor) or allogeneic stem cell transplant
• Splenectomy: palliative only for symptomatic massive splenomegaly; does not prevent blast crisis

Myelofibrosis (Agnogenic Myeloid Metaplasia - AMM)

• Clonal hematopoietic stem cell proliferation → marrow fibrosis → extramedullary hematopoiesis in spleen
• Blood smear: nucleated RBCs, teardrop poikilocytes (dacrocytes), immature myeloid elements (96% of cases)
• Only curative therapy: allogeneic bone marrow transplant (young high-risk patients)
• Splenectomy for: symptomatic splenomegaly, anemia, thrombocytopenia, portal hypertension
• Mayo Clinic 30-year data: 76% response at 1 year, 28% complication rate, 21 perioperative deaths in 314 patients

Polycythemia Vera (PV)

• Clonal proliferation of erythroid, myeloid, and megakaryocytic lineages
• Splenomegaly in majority; splenectomy for symptomatic relief

Essential Thrombocythemia (ET)

• Abnormal megakaryocyte growth → elevated platelets
• Splenomegaly in 1/3 to 1/2
• Splenectomy reserved for later stages (when myeloid metaplasia develops)

---

9. Splenic Abscess

• Hematogenous spread (infective endocarditis, IV drug abuse - most common)
• Ischemia from trauma or infarct
• Direct spread from adjacent organs (pancreas, colon)
• Secondary to splenic cyst/hematoma

• Small solitary abscess: CT-guided percutaneous drainage
• Large/multiloculated/ruptured: splenectomy + antibiotics

---

10. Splenic Cysts

Classification

• Small, asymptomatic: observation
• Symptomatic or enlarging: surgery
  • Preferred approach: spleen preservation (partial splenectomy, cyst decapsulation/fenestration/deroofing)
  • Simple unroofing has high recurrence; decapsulation (excise anterior wall circumferentially) preferred
  • Recurrent cysts: partial splenectomy
  • Percutaneous drainage: controversial due to high recurrence
• Hydatid cyst: careful surgical excision without spillage (scolicidal agents)

---

11. Splenic Tumors

Benign Tumors

Malignant Tumors

Splenic Peliosis

• Multiple blood-filled "cystic" cavities in red pulp due to sinusoidal dilation
• Associated with HIV, steroids, OCP, Hodgkin's lymphoma, multiple myeloma
• Risk: spontaneous rupture causing hemorrhagic shock
• Treatment: splenectomy (even when found incidentally due to bleeding risk)

---

12. Wandering Spleen (Ectopic Spleen)

• Spleen located in lower abdomen or pelvis (not LUQ) due to laxity of peritoneal attachments
• 10x more common in females; also seen in children
• ~50% asymptomatic
• Symptoms: acute torsion (most common) or rupture after trauma
• Treatment:
  • Life-threatening hemorrhage: splenectomy
  • Incidentally found or torsion without infarct: laparoscopic splenopexy (spleen-preserving)

---

13. Splenectomy

Indications

Approaches

Operative Steps (Open)

1. Midline or left subcostal incision; self-retaining retractor
2. Retract stomach medially; enter lesser sac via gastrosplenic ligament
3. Identify and ligate splenic artery first (before vein - allows drainage of blood from spleen, reduces size)
4. Control splenic vein
5. Mobilize spleen medially, divide ligaments (splenophrenic, splenocolic, splenorenal)
6. Careful preservation of the tail of pancreas to avoid pancreatic fistula
7. Inspect splenic fossa for hemostasis

Pre-operative Preparation

• Vaccinations at least 2 weeks before elective splenectomy: Pneumococcal (23-valent), H. influenzae type B, Meningococcal, Seasonal influenza
• Blood products ready (FFP, cryoprecipitate, platelets for thrombocytopenic patients)
• For ITP: platelet transfusion given only after splenic artery ligation
• Splenic artery embolization before elective splenectomy: may reduce blood loss for massive splenomegaly (no definitive evidence)

---

14. Overwhelming Post-Splenectomy Infection (OPSI)

Key Facts

Causative Organisms (in order)

1. Streptococcus pneumoniae (~50%) - most important
2. Haemophilus influenzae type B
3. Neisseria meningitidis
4. Gram-negative organisms (E. coli, Klebsiella, Pseudomonas)
5. Capnocytophaga canimorsus (dog bite) - classic

Clinical Presentation

• Begins as flu-like illness → rapid deterioration
• Fulminant sepsis, DIC, bilateral adrenal hemorrhage (Waterhouse-Friderichsen syndrome)
• Characteristic feature: severity disproportionate to initial symptoms

High-Risk Groups

• Children (greatest risk - immune system not mature)
• Splenectomy for hematologic malignancy (lymphoma, thalassemia)
• Within first 2 years of splenectomy

Prevention

• Vaccination (most effective strategy): ideally preoperative (2 weeks before); if emergency, give 2-3 weeks post-op when immune response recovers
  • Pneumococcal (23-valent PPSV23 + PCV13)
  • H. influenzae type B (Hib)
  • Meningococcal (MCV4)
  • Annual influenza
• Antibiotic prophylaxis:
  • Children: Penicillin V 125 mg BD until age 3, then 250 mg BD until age 5 (some guidelines say lifelong)
  • Adults: not universally agreed; penicillin V or amoxicillin for 2 years minimum
• Patient education: carry antibiotic card; early antibiotics at first sign of infection; avoid dog bites; take prophylaxis before dental procedures/travel

Treatment of Suspected OPSI

• Immediate IV broad-spectrum antibiotics (e.g., ceftriaxone) - do not wait for culture results
• ICU admission; aggressive resuscitation

---

15. Post-Splenectomy Blood Changes

Note: Post-splenectomy thrombocytosis can mimic sepsis when platelet count is very high. If thrombocytosis >1,000,000/µL, antiplatelet therapy (aspirin) may be needed to reduce thrombotic risk.

---

16. Summary Table - Surgical Indications by Condition

---