Gut, 1969, 10, 336-351 Gut: first published as 10.1136/gut.10.5.336 on 1 May 1969. Downloaded from Postmortem survey of diverticular disease of the colon L. E. HUGHES From the Department ofSurgery, University of Queensland, and the Princess Alexandra Hospital, Brisbane Part I Diverticulosis and diverticulitis Diverticular disease of the colon is a common each of 100 consecutive colons, the first taken during cause of morbidity among many western races, winter and the second during summer. The colons in and, being especially a disease of the elderly, is this series were fixed in the undistended state, and all personally examined 24 to 48 hours after fixation. The becoming a problem ofincreasing magnitude. mesentery and associated fat was dissected from the Abdominal symptoms are common in this age left colon, and the bowel carefully examined from group, and in the absence of evidence of other internal and external aspects for the presence of diver- disease, the finding of diverticula on x-ray examin- ticula. In this way small diverticula 2 to 3 mm in diameter ation is prone to lead to a diagnosis of 'diverticulitis'. were readily found. The colon and pericolic tissues were The frequency with which such an association is a carefully examined for signs of recent or old infection, chance one, without causal relationship, would and sections were taken from such areas for histological depend on the incidence of diverticulosis in the study. normal population. Among details routinely recorded during necropsies at this hospital are the presence or absence of gallstones, It is probable that the present safety of colonic an assessment of the degree of atheroma of the aorta, surgery is the major reason for a tendency to treat and the thickness of the subcutaneous fat at the diverticular disease by resection at an early stage, umbilicus. These details were taken from the postmortem for there has been little work reported on the records for correlation with the presence of diverti- http://gut.bmj.com/ natural history of the disease when treated con- cula. The clinical records of all patients were studied to servatively to prove that routine surgical excision determine the cause of death and the presence of coexist- is justified. The work which has been reported ent disease, including hypertension, and the presence of suggests that the disease is not as inexorable in its bowel symptoms at the time of admission or as recorded progress to serious complications as much surgical in the past history. literature implies (Bolt and Hughes, 1966; Horner, 1958). INCIDENCE AND RESULTS Detailed studies of the pathology of diverticular on October 1, 2021 by guest. Protected copyright. disease are also surprisingly few, considering its INCIDENCE OF DIVERTICULA IN THE COLON Diver- importance as a cause of morbidity, while very little ticula were found in 90 of the 200 colons (Table I). indeed is known of its aetiology. Deficiences in knowledge of aetiology and basic pathology make TABLE I rational treatment difficult. This, together with the INCIDENCE OF DIVERTICULA OF COLON RELATED TO AGE tendency to frequent diagnosis and radical therapy, AND SEX1 may readily lead to overtreatment. Age No. Diverticula (%) This work has been carried out to determine the Group in Group incidence of diverticula and associated pathology Males Females Total in Queensland, to attempt to assess the relationship 10-30 4 0 0 0 of diverticula to symptoms, and to seek any evidence 31-50 23 12 6 9 51-70 72 33 41 36 which may throw light on the aetiology of this 71 + 101 60 54 56 condition. Over 50 173 48 47 48 All ages 200 45 40 43 MATERIALS AND METHODS 'Solitary caecal diverticula excluded. Colons were studied from 200 unselected necropsies at In five of these the caecum alone was involved. As the Princess Alexandra Hospital, Brisbane, in two series this may be a distinct condition, these have been 336 Gut: first published as 10.1136/gut.10.5.336 on 1 May 1969. Downloaded from Postmortem survey of diverticular disease of the colon 337 The distribution of diverticula around the circumference of the bowel, in particular in the sigmoid colon, did not differ from that reported by other workers (Slack, 1962; Watt and Marcus, 1964). A I 1 CAECAL DIVERTICULA Diverticula involved the 13 (150/o) 23 (26 °/o) 2.7 (30 °/o) caecum in 24 cases. In 14 the caecum was involved in continuity with extensive diverticulosis of the rest of the colon. In the other 10 cases, the caecum was involved more or less discontinuously, and the details of this group are set out in Table II. Five of the 10 cases were primary caecal diverticula in that they were not associated with other diverticula, and a further two cases were accompanied by early 5(5 sigmoid diverticular disease only. It is probable that 4 (4 °/o) 14 (16 `/o) 5 (5 O/°) these two patients also are cases of true 'solitary' IRREGULAR 4 (4 olo) diverticula and have subsequently developed sig- FIG. 1. Incidence of diverticula at necropsy. In 200 moid diverticular disease; both were aged less cases diverticula were present in 90. than 65 years. The three cases associated with more extensive left-sided diverticular disease might be excluded to give an overall incidence of 43 % of merely an extension of the general process, or colonic diverticula. Little difference w'as found in might also be primary caecal disease with coincident incidence between the two sexes. but unrelated left-sided diverticular disease. The The distribution of diverticula thr4oughout the incidence of solitary caecal diverticula in this series, length of the colon is shown in Figiure 1. Early therefore, lies between 2.5 and 5% and is probably diverticular disease, a group arbitrarilIy formed of about 3.5%. Histologically all the diverticula were thin-walled, 'false' diverticula (Fig. 2). No those in whom less than five diverticula were present http://gut.bmj.com/ in the sigmoid colon, was found in 6.5 % of the example of the 'congenital' diverticulum containing series or in 14% of those with divertticula. As in all muscle coats in its wall was seen. In two cases most reported series the sigmoid colon 'was involved more than one diverticulum was present in the in almost all cases (99 %), there being anly one case caecum (Fig. 3). The diverticula varied from a with diverticula elsewhere where the silgmoid colon few millimetres to 15 mm in diameter, and were was not affected, diverticula localized tc the caecum randomly distributed around the caecum, occurring being excluded. In this case there were two isolated on both mesenteric and peritoneal aspects. diverticula, one each at the splenic and hepatic on October 1, 2021 by guest. Protected copyright. flexures. The remaining three cases, classified as AGE The relationship between age and the extent 'irregular', showed diverticula of the right colon of the disease is shown in Table III, where the associated with sigmoid diverticula, thec intervening median age of patients in each group is given. bowel being unaffected. Cases of total colonic involvement occur at a later TABLE II CAECAL DIVERTICULA1 Case Age Caecal Distance from Other Muscle Change (yr) Diverticula Ileo-caecal Valve (cm) Diverticula in Sigmoid Colon 76 10 Left colon Present 2 68 5 Nil 3 99 16 Nil 4 49 3 2-5 Sigmoid Present 5 49 2 3,8 Nil 6 79 8 Left colon Present 7 62 8 Sigmoid 8 70 8 Left colon 9 57 7.5 Nil Present 10 64 15 Nil Present 'Excluding caecal involvement in continuity with diffuse colonic diverticula. 338 L. E. Hughes Gut: first published as 10.1136/gut.10.5.336 on 1 May 1969. Downloaded from or thickening, whereas diverticula proximal to the sigmoid colon usually had wide necks. The combi- nation of a wide neck and soft or liquid faeces probably accounts for the rarity of inflammatory disease proximal to the sigmoid. However, the converse is not always true. Some colons had large diverticula containing faecoliths which had ob- viously been in situ for a very long time yet showed no microscopic evidence of inflammation. Jejunal diverticula of the typical multiple, mes- FIG. 2. Section of a large solitary diverticulum of the enteric type are occasionally associated-perhaps caecuim ofthe 'false' type. (Scale: 1 division = 1 mm.) by chance-with colonic diverticula. Ileal diverticula have been reported much less commonly. In two cases in this series, small (5 mm) false diverticula were situated just proximal to the ileo-caecal valve (no jejunal diverticula were present). The first case was noted towards the end of the series and until this time the small bowel had not been examined, so the incidence of terminal ileal diverticula asso- ciated with colonic diverticula could not be assessed. Spriggs and Marxer (1925), from their radiological FIG. 3. A section of caecum showing two 'solitary' studies, described these diverticula of the terminal caecal diverticula. (Scale: 1 division = 1 mm.) ileum in association with colonic diverticula. Chronic periileal inflammatory disease is occasion- age than lesser degrees of affection. In fact no case ally seen in this region and these diverticula may be a of total colonic involvement was seen in this series causative factor in this lesion. under the age of 70 years, although caecal involve- ment in association with diverticula of the distal EARLY DIVERTICULA A particular study was made left colon was seen three in of the histological findings in cases of very small times patients under and early diverticula. At this stage, when the diverti- this age. Involvement of the caecum alone occurred http://gut.bmj.com/ in an earlier age group, as is typically found in cula are less than 2 mm in diameter, the diverti- cula move very easily in and out of the bowel through clinical diverticulitis of this region.