Segal WN, Greenberg PD, Rockey DC, Cello JP, McQuaid KR. Multiple hemorrhoidal ligation: a prospective, randomized trial evaluating a new technique. J S C Med Assoc 1985 81(7):398–401.ĭennison AR, Whiston RJ, Rooney S, Morris DL. Dis Colon Rectum 1991 34(7):585–591 discussion 591–593.īanov L Jr, Knoepp LF Jr, Erdman LH, Alia RT. Temporal changes in the occurrence of hemorrhoids in the United States and England. The prevalence of hemorrhoids and chronic constipation. Endoglin (CD105) expression in the development of haemorrhoids. Hemorrhoidectomy during pregnancy: risk or relief? Dis Colon Rectum 1991 34(3):260–261. Saleeby RG Jr, Rosen L, Stasik JJ, Riether RD, Sheets J, Khubchandani IT. Hypertensive anal cushions as a cause of the high anal canal pressures in patients with haemorrhoids. A prospective study of the effect of haemorrhoidectomy on sphincter function and faecal continence. Read MG, Read NW, Haynes WG, Donnelly TC, Johnson AG. Lateral internal sphincterotomy together with haemorrhoidectomy for treatment of haemorrhoids: a randomised prospective study. Galizia G, Lieto E, Castellano P, Pelosio L, Imperatore V, Pigantelli C. Haemorrhoids: pathology, pathophysiology and aetiology. Loder PB, Kamm MA, Nicholls RJ, Phillips RK. Arterio‐venous anastomoses in the anal region with reference to the pathogenesis and treatment of haemorrhoids. The importance of the musculus canalis ani for continence and anorectal diseases (author's transl). This process is experimental and the keywords may be updated as the learning algorithm improves. These keywords were added by machine and not by the authors. The subepithelial vessels and sinuses above the dentate line which constitute the internal hemorrhoid plexus are drained by way of the middle rectal veins to the internal iliacs. This overlying tissue is somatically innervated and is therefore sensitive to touch, pain, stretch, and temperature. Venous drainage also occurs to a lesser extent via the middle rectal veins to the internal iliac veins. The venous plexus and sinusoids below the dentate line which constitute the external hemorrhoidal plexus drain primarily via the inferior rectal veins into the pudendal veins which are branches of the internal iliac veins. This is supported by the bright red appearance and the arterial pH of the blood. Studies have shown that hemorrhoidal bleeding is arterial and not venous because hemorrhage from disrupted hemorrhoids occurs from presinusoidal arterioles that communicate with the sinusoids in this region. The lack of a muscular wall characterizes these vascular structures more as sinusoids and not veins. These smooth muscle fibers then pass through the internal sphincter and anchor themselves into the submucosa, thereby contributing to the bulk of the hemorrhoids and suspending the vascular cushions at the same time.2 Some of the vascular structures within the cushion when examined microscopically lack a muscular wall. These cushions of thickened submucosa contain blood vessels, elastic tissue, connective tissue, and smooth muscle.1 The anal submucosal smooth muscle (Treitz’s muscle) originates from the conjoined longitudinal muscle (see Figure 11-1). The term “hemorrhoidal disease” should be reserved for those vascular cushions that are abnormal and cause symptoms in patients. Hemorrhoids are cushions of specialized, highly vascular tissue found within the anal canal in the submucosal space.
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