Clinical Analysis of Colorectal Perforation : Focus on Unusual Causes

ABSTRACT

PURPOSE: Colorectal perforation is a rare malady, but it usually presents abdominal emergency with high morbidity and mortality. It is very difficult to diagnose stercoral, idiopathic, or steroid induced perforation because these are very rare, but they show high mortality. The aims of this study are to 1) evaluate and compare the characteristics of stercoral, idiopathic and steroid induced perforation with other perforations; and to 2) guide the diagnostic approach and treatment of these rare colon perforations. METHODS: We retrospectively reviewed thirty five patients underwent surgery for colorectal perforation at the Department of Surgery, Daedong Hospital, from November 1996 to January 2005. Age, gender, perforation site, grade of peritonitis, methods of operation and mortality rates were compared between the various causes. Logistic regression was used to evaluate their effect on mortality. RESULTS: There were 10 cases of iatrogenic colorectal injuries (28%), 7 of steroid induced colorectal perforation (20%), 5 of stab (14%), 4 of diverticulitis (11%), 4 of stercoral (11%), 3 of idiopathic (8%), and 2 of cancer induced perforation (5%). Total mortality rate of all the cases was 28.5% (10 out of 35) but the mortality of stercoral, steroid induced and idiopathic perforation was 57% (8 out of 14). The mortality rate was higher in older age group (60 years above) (40%), stercoral (75%), steroid induced (57%) and idiopathic (33%), preoperative systemic inflammatory response (SIRS) (42%), preoperative septic shock (83%), abnormal WBC count (10,000/mm3 above or 4,000/mm3 below) (53%), left colon perforation (36%) and diffuse peritonitis (56%). The mortality rate was lower in young age group (13%), iatrogenic (10%), stab (0%), right colon perforation (10%) and localized peritonitis (5%). The peritonitis grade (Hinchey's stage) of idiopathic group, cancer and stercoral was worse (III-IV grade 75%, 100%, 75%) than that of diverticulitis, iatrogenic and stab (III-IV grade 25%, 30%, 40%). CONCLUSION: The stercoral, steroid induced and idiopathic colorectal perforation was rare, difficult to diagnose but it showed high mortality. The characteristics of these are an older age, presenting with a high peritonitis grade, preoperative SIRS, preoperative septic shock, and occurrence below the splenic flexure. If surgeons encounter these perforations, they should perform prompt surgical management and intensive postoperative care to reduce the mortality.