Colonic Manifestations of Portal Hypertension
Colonic manifestations of portal hypertension include enlarged hemorrhoids, rectal varices and endoscopic features of diffuse vascular ectasia. The frequency of at least one of these features in patients with cirrhosis has been estimated at 50–90%. By analogy with the upper gastrointestinal tract, the term portal colopathy should probably be restricted to diffuse vascular ectasia. Colonic manifestations of portal hypertension often coexist with other features of portal hypertension such as esophageal varices and portal gastropathy and seems likely to be related, at least in part, to the degree of elevation of portal venous pressure. In contrast to bleeding from esophageal varices, bleeding from rectal varices only occurs in approximately 1% of patients with cirrhosis. This low frequency of bleeding may be related to varices that have thicker walls or varices that are less superficial than those in the lower esophagus. However, when bleeding occurs, methods for the control of bleeding are similar. For example, endoscopic ligation and sclerotherapy have been used for bleeding rectal varices while various thermocoagulative techniques have been applied to bleeding vascular lesions. Other measures such as non-selective beta-blocking drugs and portal decompression may also be considered in individual patients.
The appearance at colonoscopy of rectal varices and vascular ectasia are shown in Figures 1 and 2, respectively. Rectal varices project into the lumen of the rectum immediately above the anal canal. Varices may have a bluish color and become less obvious when the rectum is inflated with air. With vascular ectasia, endoscopic signs include red spots, vascular dilatation and tortuosity. This is sometimes associated with diffuse erythema, edema and friability that may raise the possibility of mild colitis. Whether portal colopathy is aggravated by obliteration of esophageal varices remains unclear. In studies in rodents, portal hypertension has the greatest effect on the microvasculature of the ascending colon and rectum and this appears to apply in humans.
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Colonic manifestations of portal hypertension include enlarged hemorrhoids, rectal varices and endoscopic features of diffuse vascular ectasia. The frequency of at least one of these features in patients with cirrhosis has been estimated at 50–90%. By analogy with the upper gastrointestinal tract, the term portal colopathy should probably be restricted to diffuse vascular ectasia. Colonic manifestations of portal hypertension often coexist with other features of portal hypertension such as esophageal varices and portal gastropathy and seems likely to be related, at least in part, to the degree of elevation of portal venous pressure. In contrast to bleeding from esophageal varices, bleeding from rectal varices only occurs in approximately 1% of patients with cirrhosis. This low frequency of bleeding may be related to varices that have thicker walls or varices that are less superficial than those in the lower esophagus. However, when bleeding occurs, methods for the control of bleeding are similar. For example, endoscopic ligation and sclerotherapy have been used for bleeding rectal varices while various thermocoagulative techniques have been applied to bleeding vascular lesions. Other measures such as non-selective beta-blocking drugs and portal decompression may also be considered in individual patients.
The appearance at colonoscopy of rectal varices and vascular ectasia are shown in Figures 1 and 2, respectively. Rectal varices project into the lumen of the rectum immediately above the anal canal. Varices may have a bluish color and become less obvious when the rectum is inflated with air. With vascular ectasia, endoscopic signs include red spots, vascular dilatation and tortuosity. This is sometimes associated with diffuse erythema, edema and friability that may raise the possibility of mild colitis. Whether portal colopathy is aggravated by obliteration of esophageal varices remains unclear. In studies in rodents, portal hypertension has the greatest effect on the microvasculature of the ascending colon and rectum and this appears to apply in humans.
(Enlarge Image)
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CLICK HERE for subscription information about this journal.
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