Splenic disorders

Key points

The spleen is an important organ in haematologic regulation and immune defence

Common surgical considerations include congenital anomalies, trauma and haematologic disorders

Preservation of splenic tissue is preferred when possible due to its immune function

Loss of splenic function carries a lifelong risk of overwhelming post-splenectomy infection (OPSI)

Embryology

Develops from mesenchymal cells in the dorsal mesogastrium during weeks 4–5 of gestation

Not derived from endoderm, unlike other lymphoid organs

By weeks 6–7, gastric rotation shifts the spleen from the midline to the left upper quadrant

Multiple splenic cell clusters coalesce and vascularise, forming a lobulated organ that later smooths

Splenic notches on the superior border represent remnants of this lobulation

Anatomy

Located in the left upper quadrant beneath ribs 9–11, posterior to the stomach and superior to the left kidney

An intraperitoneal organ suspended by peritoneal folds

Ligamentous attachments include:

• Gastrosplenic ligament connecting to the greater curvature of the stomach and containing short gastric vessels

• Splenorenal ligament attaching to the left kidney and containing the splenic vessels and tail of the pancreas

• Phrenosplenic and splenocolic ligaments connecting to the diaphragm and colon respectively

Vascular Supply

Arterial supply from the splenic artery, a branch of the coeliac trunk which divides into 5 or more segmental branches within the splenorenal ligament

Venous drainage through the splenic vein which joins the superior mesenteric vein behind the pancreas to form the portal vein

Segmental vascular distribution makes partial splenectomy feasible

Relations

Anteriorly – stomach

Posteriorly – diaphragm, left pleura, 9th–11th ribs

Inferiorly – left colic flexure

Medially – left kidney, pancreas tail

Histology and Function

Red pulp (around 75%) filters blood through venous sinusoids containing macrophages that remove aged, damaged or abnormal red blood cells including spherocytes and sickled cells

White pulp (around 25%) is composed of lymphoid follicles containing T and B lymphocytes responsible for humoral and cellular immunity

The marginal zone is important for response to encapsulated bacteria

The spleen also serves as a reservoir for platelets and monocytes which can be rapidly mobilised during inflammation or injury

Congenital and Anatomical Variants

Accessory spleens (splenunculi) occur in 20–30% of individuals, usually near the splenic hilum, within ligaments, omentum or pancreatic tail

They may provide partial immune function after splenectomy but must be removed in therapeutic splenectomy for haematologic disease

Wandering spleen results from absence or laxity of suspensory ligaments leading to splenic mobility and risk of torsion

Managed with splenopexy in viable spleen or splenectomy if infarcted

Splenogonadal fusion is a rare anomaly where splenic tissue fuses with gonadal structures

Continuous type has a fibrous connection between the spleen and gonad

Discontinuous type consists of isolated splenic tissue near the gonad or along its descent

May present as a scrotal or abdominal mass and is managed by excision of ectopic tissue with testicular preservation where possible

Asplenia and polysplenia are part of heterotaxy syndromes and associated with complex cardiac anomalies

Splenic Cysts

Congenital cysts arise from mesothelial inclusions or epithelial remnants

Acquired cysts follow trauma, infarction or infection

Infectious cysts may be bacterial, fungal or parasitic

Hydatid cysts due to Echinococcus species are common in endemic regions such as the Mediterranean, Middle East, North Africa, Australia and New Zealand

Imaging often shows daughter cysts at the splenic periphery and may reveal associated liver involvement

Treatment is indicated for cysts larger than 5 cm or symptomatic lesions

Management includes percutaneous aspiration and sclerotherapy or laparoscopic marsupialisation

Hydatid cysts require open excision or splenectomy with hypertonic saline irrigation, as inadvertant spillage can cause severe anaphylaxis

Postoperative Mebendazole therapy is required

Splenic Masses

Haemangiomas and hamartomas are the most common benign splenic tumours, usually incidental findings

Splenosis refers to autotransplanted splenic tissue following traumatic rupture or splenectomy

These implants are benign but provide limited immune function

Haematologic Disorders — Indications for Splenectomy

Hereditary spherocytosis results from red cell membrane defects causing anaemia, jaundice, splenomegaly and gallstones

Splenectomy is indicated in moderate to severe disease, delayed until after age 5–6 years to reduce OPSI risk

Sickle cell disease causes splenic infarction and fibrosis due to vaso-occlusion

Indications for splenectomy include recurrent sequestration, hypersplenism with pancytopenia or massive splenomegaly causing symptoms

Other indications include thalassaemia (non-transfusion dependent), idiopathic thrombocytopenic purpura, Gaucher disease, pyruvate kinase deficiency and Felty syndrome

Surgical Considerations

Preoperative preparation follows the ‘HIP in shape’ principle

Hydration to maintain intravascular volume

Immunisation at least 2 weeks preoperatively against pneumococcus, meningococcus and Haemophilus influenzae type b

Preoperative transfusion to haemoglobin around 12 g/dL if required

Intraoperative precautions avoid the three Hs – hypoxia, hypothermia and acidosis

Laparoscopic splenectomy is preferred where feasible with the patient supine and left flank elevated

Four ports and a 30° camera are used

The gastrocolic and splenocolic ligaments are divided to mobilise the colon

Short gastric vessels in the gastrosplenic ligament are divided followed by splenic vessels in the splenorenal ligament

The spleen is freed from remaining attachments, bagged and removed piecemeal

Partial splenectomy may be performed when preservation of function is desirable but is technically demanding

Page edited by Prof. Ashok Daya Ram MBBS, FRCS, FRCPS, FEBPS, FRCS (Paed Surgery), Consultant Paediatric and Neonatal Surgeon, Norfolk and Norwich University Hospital, Norwich, UK. October 2025

References

Kapila V, Wehrle CJ, Tuma F. Physiology, Spleen. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537307/

Skarsgard, Erik D, and Mary L Brandt. "Splenic Anatomic Disorders." Pediatric Surgery NaT, American Pediatric Surgical Association, 2020. Pediatric Surgery Library, www.pedsurglibrary.com/apsa/view/Pediatric-Surgery-NaT/829058/all/Splenic_Anatomic_Disorders.

Skarsgard, Erik D, and Mary L Brandt. "Splenic Disorders." Pediatric Surgery NaT, American Pediatric Surgical Association, 2020. Pediatric Surgery Library, www.pedsurglibrary.com/apsa/view/Pediatric-Surgery-NaT/829054/all/Splenic_Disorders.