COMPLICATIONS OF COLONOSCOPY

Abstract

Complications of colonoscopy were studied by analysing questionnaires sent to all the major institutes of Japan. The total number of colonoscopy was 54, 463 examinations, including 51, 196 diagnostic colonoscopies and 3, 267 polypectomies. Complications of colonoscopy occurred in 116 cases, 0.21%, in total, including perforation in 68 cases, 0.12%, bleeding in 30 cases, 0.06%, rupture of the tenia coli in 1, laceration of the serosa in 1 and others. Among those, the complications following diagnostic colonoscopy occurred in 81 cases, 0.16%, including perforation in 59 cases, 0.12%, bleeding in 7 cases, 0.014% and others. Polypectomy-induced complications were seen in 35 cases, 1.07%, including 9 cases, 0.28% of perforation, 23 cases, 0.70% of bleeding and others. Location of perforation follows: The majority, 53 of 68 cases of the perforations were in the sigmoid colon, followed by the sigmoid-descending junction and descending colon, in the order of frequency. Among 68 cases of perforation, 54 perforations occurred after colonoscopic observation alone, 5 took place after observation with biopsy, and 9 after polypectomy. Concerning the findings that led to the discovery of perforation, there were escape of the instrument tip noticed while under X-ray control, peritoneal visualisation and abdominal pain, each with the frequency of about 240. The interval between the examinations and confirmation of perforation follows : Perforation was detected during or immediately after colonoscopy in the majority of cases, but there were a considerable number of cases, in which more than 10 hours to even more than 24 hours elapsed until the detection of perforation. As the causes of perforation, there were the factors arising from the endoscopists, factors arising from the patients, and the faults with the instruments. Some were considered unavoidable. The sigmoid colon was found to be a bleeding site in almost half of the cases, followed by the rectum and descending colon in frequency. Colonoscopic procedures which caused haemorrhage were almost exclusively polypectomy. As for the interval between examination and detection of bleeding a considerable length of time elapsed in a significant number of cases. The direct causes of bleeding were insufficient cauterisation and inappropriate handling of the snare in the majority of cases. Besides, there were also bleeding tendency of the patients and the nature of the lesions. When the experience of endoscopists was compared with the accidents, the accidents occurred also by fairly experienced endoscopists, but with regard to polypectomy, accidents seemed to occur more frequently by the hands of endoscopists less experienced in polypectomy. The most important things for prevention of complications are strict decision for indi-cation, good preparation of the patients and careful manuoeuvre during the examination. There are, however, unavoidable accidents. The patients must be advised to contact the endoscopist who examined them as soon as they noticed any abnormality. This applies not only for the few hours but also for the few days after the examination.