Anorectal varices

Anorectal varices refers to the dilation of collateral submucousal vessels due to backflow in the veins of the rectum.^[1]. Typically this occurs due to portal hypertension which shunts venous blood from the portal system through the portosystemic anastomosis that are present at this site into the systemic venous system ^[2][3].This can also occur in the oesophagus, causing oesophageal varices, and at the level of the umbilicus, causing caput medusa.^[4].Between 44% and 78% of patients with portal hypertension get anorectal varices.^[3][5]

Pathogenesis

Blood from the superior portion of the rectum normally drains into the superior rectal vein via the superior mesenteric vein to the liver as part of the portal venous system. Blood from the middle and inferior portions of the rectum is drained via the middle and inferior rectal veins. In portal hypertension venous resistance is increased within the portal venous system, when the pressure in the portal venous system increases above that of the systemic blood is shunted through the portosystemic anastomoses. The shunting of blood and consequential increase of pressure through the collateral veins causes the varicosities.

Diagnosis

The terms rectal varices and haemorrhoids are often used interchangeably, but this is not correct ^[6]. Haemorrhoids occur due to prolapse of the rectal venous plexus and are no more common in patients with portal hypertension than those without ^[7]. Rectal varices however are only found in patients with portal hypertension and are common in conditions such as cirrhosis ^[8].

Treatment

Unlike oesophageal varices rectal varices are less prone to bleeding, are less serious when a bleed does occur and are easier to treat because of the more accessible location. ^[9].

Typically, treatment consists of dressing the underlying portal hypertension. Some treatments include portosystemic shunting, ligation, and under-running suturing.^[5] Insertion of a transjugular intrahepatic portosystemic shunt (TIPS) has been shown to alleviate varices caused by portal hypertension.^[1] Successful treatment of portal hypertension that subsequently reduces anorectal varices provides a confirmation of the initial diagnosis, allowing for a distinction between varices and hemorrhoids, which would not have been alleviated by reduction of portal hypertension.

References

1. ^ ^{a b} Katz, JA; Rubin, RA, Cope, C, Holland, G, Brass, CA (1993 Jul). "Recurrent bleeding from anorectal varices: successful treatment with a transjugular intrahepatic portosystemic shunt.". The American journal of gastroenterology 88 (7): 1104–7. PMID 8317414. 
2. ^ Hunt AH. 'A contribution to the study of portal hypertension. Edinburgh: Livingstone, 1958: 61.
3. ^ ^{a b} Chawla, Y; Dilawari, J B (1 March 1991). "Anorectal varices--their frequency in cirrhotic and non-cirrhotic portal hypertension.". Gut 32 (3): 309–311. doi:10.1136/gut.32.3.309. 
4. ^ Moubarak, Elie; Bouvier, Antoine, Boursier, Jérôme, Lebigot, Jérôme, Ridereau-Zins, Catherine, Thouveny, Francine, Willoteaux, Serge, Aubé, Christophe (15 October 2011). "Portosystemic collateral vessels in liver cirrhosis: a three-dimensional MDCT pictorial review". Abdominal Imaging. doi:10.1007/s00261-011-9811-0. 
5. ^ ^{a b} Hosking, SW; Smart, HL, Johnson, AG, Triger, DR (1989-02-18). "Anorectal varices, haemorrhoids, and portal hypertension.". Lancet 1 (8634): 349–52. PMID 2563507. 
6. ^ McCormack TT BHSJJA. Rectal varices are not piles. Br J Surg. Fev 1984;71(2):163.
7. ^ Jacobs DM, Bubrick MP, Onstad GP, Hitchcock CR. The relationship of haemorrhoids to portal hypertension. Dis Col Rect 1980:23(8):567-9.
8. ^ Zuberi FF ZBKMKM. Frequency of rectal varices in patients with cirrhosis. J Coll Physicians Surg Pak. Feb 2004;14(2):94-7.
9. ^ Johansen K. Bardin J. Orloff MJ. Massive bleeding from hemorrhoidal varices in portal hypertension. JAMA 1980:224 (18): 2084-5.