Heteropagus

Estimated incidence less than 1/106 births. It appears to be more common in Indian and South African populations.  Minimal form of conjoined twins (see this term) where most of one of the twins has involuted and presents as an external or internal outgrowth. Sometimes called parasitic twin or ex-fetal fetus (not to be confused with fetus in foetu, which is a form of teratoma).

The parasite can present as a supernumerary limb, an oropharyngeal mass, an abdominal mass, a caudal duplication etc ... The most common forms are rachipagus (42 %) or omphalopagus (38 %).

The normal newborn may present with a cardiac malformation, an omphalocele or a spinal malformation (myelomeningocele, tethered spinal cord).



Anesthetic implications:

echocardiography; according to the localization of the parasite. Risk of important hemorrhage.


References :

-        Surendran N, Mani Nainan K, Paulose MO.
An unusual case of caudal duplication.
J Pediatr Surg 1986; 21: 924-5

-        Chadha R, Bagga D, Dhar A, Malhotra CJ, Taneja SB.
Epigastric heteropagus.
J Pediatr Surg 1993; 28: 723-7

-        Sharma G, Nazarian Mobin SS, Lypka M, Urata M.
Heteropagus (parasitic twins: a review.
J Pediatr Surg 2010; 45: 2454-63.

-        Singh B, Sarin A, Choudhary SR. 
Anaesthetic considerations in the management of heteropagus twins.
Pediatr Anesth 2004; 14: 191-2.

-        Mathur P, Sharma S, Mittal P, Yadav RK, Barolia D.
Heteropagus twins: six cases with systematic review and embryological insights.
Pediatr Surg Int 2022; 28:963-83

-        Mathur P, Sharma S, Mittal P, Yadav RK, Barolia D.
Heteropagus twins: six cases with systematic review and embryological insights.
Pediatr Surg Int 2022; 28:963-83


Updated: June 2022