On diseases of the rectum and anus / by Harrison Cripps.

  • William Harrison Cripps
Date:
1907
Catalogue details

Licence: Public Domain Mark

Credit: On diseases of the rectum and anus / by Harrison Cripps. Source: Wellcome Collection.

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    veins, which, uniting, eventually form the inferior mesen¬ teric. For the first three inches the rectal veins run beneath the mucous membrane between it and the muscular coats. They then perforate the muscular 'coats running the rest of their course external to the bowel. Much attention has been called to the fact that the veins pass through the muscular walls, especially by Verneuil, who believed that the contraction of the muscular fibres of the rectum was one of the active causes of internal haemor¬ rhoids, by obstructing the flow of blood to the portal cir¬ culation, a view which I consider there is little evidence to support. Most standard works on anatomy * state that the haemorrhoidal branches of the inferior mesenteric vein inosculate freely with those of the internal iliac, thus establishing a communication between the portal and systemic veins. Such a communication may exist at the anal margin of the rectum, but I believe it is extremely slight, and moreover, if it does exist, the flow of blood can only be in one direction—viz., towards the iliacs. This I have been able to demonstrate by the following experiments: (1) The hsemorrhoidal plexus cannot be injected through the iliac veins, proving that if a com¬ munication exists valves must prevent the blood flow¬ ing in this backward direction. (2) The hsemorrhoidal plexus can be at once injected through the inferior mesen¬ teric, but the injection will not pass on into the iliac veins, so that if any communication exists it must be very slight. The foregoing experiments in great measure corroborate the view so ably maintained by John Gay,t in his well- known work on hamiorrhoidal diseases. The nerves supplying the highly sensitive surface about the anal margin are derived both from the fourth sacral and the pudic, while the external sphincter and * Morris’s “Anatomy,” 3rd edition, 1902, p. 659 ; Gray’s “ Anatomy,” 16th edition, p. 748 ; also Quain’s “ Anatomy,” 10th edition, vol. ii. pt. ii. p. 541. | “ On Haemorrhoidal Disorders,” 1882, by John Gay.