Aspleni

Aspleni is not a widely used medical term; in most contexts it refers to asplenia, the absence of the spleen. Asplenia may be congenital or acquired, and can occur in isolation or as part of broader congenital anomaly syndromes. Acquired asplenia most often results from surgical removal of the spleen (splenectomy) after trauma or for disease.

Congenital asplenia occurs when the spleen fails to develop or is absent at birth. It can be isolated or associated with heterotaxy syndromes, where the arrangement of internal organs is abnormal. Acquired asplenia arises after splenectomy or, less commonly, from conditions that destroy splenic tissue. The functional consequences depend on whether splenic tissue remains (functional asplenia) or is completely absent.

The spleen plays a key role in filtering bacteria and mounting immune responses, especially against encapsulated organisms such as Streptococcus pneumoniae, Haemophilus influenzae type b, and Neisseria meningitidis. People without a functioning spleen have an increased risk of severe and rapidly progressive infections, a risk often termed overwhelming postsplenectomy infection (OPSI) in surgical contexts.

Diagnosis is usually imaging-based, with ultrasound or CT confirming the absence of splenic tissue. Clinical assessment includes vaccination history and susceptibility to infections. Management emphasizes prevention of infection: timely immunization against pneumococcus, H. influenzae type b, and meningococcus; consideration of antibiotic prophylaxis in children and certain adults; and prompt treatment of fever or infection. Education on seeking early medical care is important for asplenic individuals.

See also: Splenectomy, Asplenia, Heterotaxy.