Abernethy malformations are an extremely rare anomalous group of the splanchnic venous system. They comprise of congenital portosystemic shunt and results from persistence of embryonic vessels.
Type I malformations are thought to only occur in females with type II having a male predilection 1.
At least two main types of Abernethy malformations 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 congenital absence of the portal vein with complete diversion of portal blood into systemic veins (the inferior vena cava, or renal or iliac veins). These are further subdivided into those in which the splenic and superior mesenteric veins end up separately at the systemic veins, and those in which the splenic and superior mesenteric veins join to form a common trunk that ends up at the IVC, right atrium, or iliac veins
- type Ia : separate drainage of the superior mesenteric and splenic veins into systemic veins
- type Ib : superior mesenteric and splenic veins join to form a short extra-hepatic portal vein which drains into a systemic vein
In type II shunts (side to side), there is a hypoplastic portal vein with portal blood diversion into the vena cava through a side-to-side, extrahepatic communication.
Recognised associations include:
- hepatic encephalopathy: from portosystemic shunting
- hepatic mass lesions
- hepatopulmonary syndrome 2
pulmonary arteriovenous fistulae:
- thought to be due to hyperammonaemia
- may lead to systemic emboli
- other congenital abnormalities - particularly type I 1
It was named after John Abernethy in 1793 who gave the first account of an absent portal vein and a congenital mesentericocaval shunt 1,5.
- 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
- 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
- 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
Synonyms & Alternative Spellings
|Synonyms or Alternative Spelling||Include in Listings?|
|Congenital absence of the portal vein||✓|
|Congenitally absent portal vein||✗|