emorrhoidal Disease: A Comprehensive Review

natomy and physiology emorrhoids are vascular cushions within the anal caal, usually found in three main locations: left lateral, ight anterior, and right posterior portions. They lie beeath the epithelial lining of the anal canal and consist of irect arteriovenous communications, mainly between he terminal branches of the superior rectal and superior emorrhoidal arteries, and, to a lesser extent, between ranches originating from the inferior and middle hemrrhoidal arteries and the surrounding connective tissue. The vascular cushions participate in the venous drainge of the anal canal. It has been suggested that their resence is essential for continence; they contribute aproximately 15% to 20% of the resting anal pressure, so hey intensify the action of the anal sphincter mechaism and shield the anal canal and the anal sphincter uring the act of evacuation by filling with blood and roviding extra padding. The vascular cushions congest uring a Valsalva maneuver or when intraabdominal ressure is increased, enabling the anal canal to remain losed; decongestion of the cushions, achieved by a rapid ecrease of anal tone, allows rapid emptying of the rectal ontent.