The Retrorectal Soft-Tissue Space in Ulcerative Colitis

During the past few years, there has been an increasing tendency toward radical surgical intervention in severe ulcerative colitis. In cases with slight or moderate inflammatory rectal changes, when the perirectal soft tissues are not involved, colectomy with preservation of the rectum and ileorectostomy is the operation of choice (Ehrenpreis et al., 2). The preoperative knowledge of the appearance of these tissues is therefore important to the surgeon. Increase of the retrorectal soft-tissue space in ulcerative colitis was reported by Ilha and Job (3) and by Edling and Eklöf (1) in adults and by Rudhe (5) in children. The relationship of this finding to the inflammatory changes in the large bowel has previously received only slight attention. In the present paper this relationship will be considered at some length, as will correlation with other features of the disease. Method and Material The retrorectal soft-tissue space is roentgenologically estimated in true lateral projections of the rectum and sacrum in the routine barium enema examination. The evaluation must be done on films showing rectal distention, exposed during contrast filling. The shortest distance between the dorsal contour of the barium column and the ventral surface of the sacrum should be measured at the level of S3–S5. In this way, the rectal wall is included in the measurements. In 95 of 100 adult patients with nonspecific gastrointestinal symptoms and normal appearance of the large bowel at barium enema examination, the distance was 5 mm. or less (Figs. 1 A and 2 A). In 3 patients the distance was 6 to 7 mm.: in 2 obese patients 9 to 10 mm. On this basis, a distance between 1 and 2 cm. is regarded as a moderate increase, and a distance of more than 2 cm. as a marked increase of the retrorectal soft tissue. Our series of ulcerative colitis comprises 197 cases (95 in males and 102 in females). The diagnosis was made clinically in the medical department of Karolinska Sjukhuset. Of these patients, 94 had a normal, and 103 an increased retrorectal soft-tissue space; the average duration of the disease in the two groups was 16.4 and 19.5 years, respectively. The increase was moderate in 68 and marked in 35 cases (Figs. 1 and 2), the largest figure being about 7 cm. Of the 103 patients, 54 were males and 49 females. Results In 23 of the patients with an increase of the retrorectal soft tissues, the feature was not present on an initial barium enema examination but occurred later. It would, of course, be of interest to know the duration of colitis up to the initial increase of the soft-tissue space, but this could not be determined in this series with any high degree of accuracy. The first roentgen examination of the large bowel was performed close to the onset of disease in only a few cases. Furthermore, the subsequent examinations followed at various intervals, without any homogeneous pattern.