Abernethy malformations are rare vascular anomalies of the splanchnic venous system. They consist of congenital portosystemic shunts and result from persistence of the embryonic vessels.
Type I malformations are thought to occur only in females, while type II have a male predominance 1.
There are two main types of Abernethy malformations that have been described (initially devised by G Morgan and R Superina 6):
- type I: end-to-end shunts
- type II: side-to-side shunts
In type I shunts (end-to-end), there is a congenital absence of the portal vein with a complete diversion of portal blood into systemic veins (inferior vena cava, renal veins, or iliac veins). These are further subdivided into:
- type Ia: separate drainage of the superior mesenteric vein and splenic vein into systemic veins
- type Ib: superior mesenteric vein and splenic vein join to form a short extra-hepatic portal vein which drains into a systemic vein (inferior vena cava, right atrium or iliac veins)
In type II shunts (side-to-side), there is a hypoplastic portal vein with portal blood diversion into the inferior vena cava through a side-to-side, extrahepatic communication.
- hepatic encephalopathy: from portosystemic shunting
- hepatic mass lesions
- hepatopulmonary syndrome 2
pulmonary arteriovenous fistulae
- thought to arise due to hyperammonemia
- may lead to systemic emboli
- other congenital abnormalities, particularly associated with type I 1 :
History and etymology
Named after John Abernethy, who gave the first account of an absent portal vein with accompanying congenital mesentericocaval shunt 1,5 in 1793.
- 1. Howard ER, Davenport M. Congenital extrahepatic portocaval shunts--the Abernethy malformation. J. Pediatr. Surg. 1997;32 (3): 494-7. J. Pediatr. Surg. (link) - Pubmed citation
- 2. Alvarez AE, Ribeiro AF, Hessel G et-al. Abernethy malformation: one of the etiologies of hepatopulmonary syndrome. Pediatr. Pulmonol. 2002;34 (5): 391-4. doi:10.1002/ppul.10182 - Pubmed citation
- 3. Gallego C, Miralles M, Marín C et-al. Congenital hepatic shunts. Radiographics. 24 (3): 755-72. doi:10.1148/rg.243035046 - Pubmed citation
- 7. Ringe K, Schirg E, Melter M et-al. [Congenital absence of the portal vein (CAPV). Two cases of Abernethy malformation type 1 and review of the literature]. Radiologe. 2008;48 (5): 493-502. doi:10.1007/s00117-007-1561-1 - Pubmed citation
- 4. Chandrashekhara SH, Bhalla AS, Gupta AK et-al. Abernethy malformation with portal vein aneurysm in a child. J Indian Assoc Pediatr Surg. 2011;16 (1): 21-3. doi:10.4103/0971-9261.74517 - Free text at pubmed - Pubmed citation
- 5. Abernethy J. Account of two instances of uncommon formation in the viscera of the human body. Phil Trans R Society. 1793;83:59–66.
- 6. Morgan G, Superina R. Congenital absence of the portal vein: two cases and a proposed classification system for portasystemic vascular anomalies. J. Pediatr. Surg. 1994;29 (9): 1239-41. J. Pediatr. Surg. (link) - Pubmed citation