[Spontaneous perforations of the large intestine].

Spontaneous perforation of colon is a rare disease and physiopathologic basis are actually unknown. Surgical treatment is standardized and post-operative survival is over 60%, morbidity and mortality rate depends on peritoneal contamination. In 1984 J.A. Berry classified spontaneous perforations into "stercoral" and "idiopathic" perforations on the basis of etiopathogenetical causes of lesions. Anatomopathologically stercoral and idiopathic perforations present different characteristics. Macroscopically stercoral perforation origines from an ulcerative lesion often situated on the sigmoid colon or rectum. Microscopical characteristic is represented by a superficial ischemic necrosis of mucosa (caused by fecalomas) followed by an extension to sub-mucosa and muscular tissues of the colonic wall. On the contrary, "idiopathic perforation", frequently situated on the sigma, is a linear laceration of anti-mesenteric side of the colon without pathologic modifications of the colon. Physiopathologic basis of spontaneous perforations of the colon were also discussed. Stercoral perforation is often a consequence of chronic constipation. Instead, two hypoteses are advanced as regards idiopathic perforations. S.V. Kessing e coll. (1962) hypotized a parietal suffering caused by ischemia of anti-mesenteric side of the colon, depending on ipoperfusion of colonic tissues; they also hypotized a constitutional weakness of colonic wall as a cause of idiopathic perforation. Others hypotized an intraluminal hypertension caused by intestinal hernias (J.W. Eadie, 1955; K. Cronin, 1959), rectal prolapse or abnormal depth of Douglas cavity (D.C. Lyon, 1969). In these cases, lesion is caused by contraction of abdominal muscles during defecation, which presses colonic wall during distension.(ABSTRACT TRUNCATED AT 250 WORDS)