Cheung, a 53-year-old ulcerative colitis patient, needs to undergo colonoscopy screening at the Queen Elizabeth Hospital (QEH) on a regular basis. On 13 June, his doctor found six polyps in Cheung’s colon during the colonoscopy. He then took the chance to remove them. Although most polyps are not cancerous, it is recommended to remove the polyps during a colonoscopy, since some can be precancerous.

Unfortunately, the patient experienced severe stomach pain after the colonoscopy procedure—and, later diagnosed of perforation. Surgery was then arranged to close the hole and treat the condition. After 11 days of hospital stay, the patient was released on 26 June.

The incident was reported by Oriental Daily News on 25 July. According to the article, Cheung’s family members claimed the prevalence of perforation in colonoscopy is as low as one in 10,000 cases. The article also quoted statistics from the Department of Health (DH)’s CRC Screening Pilot Programme—noting there was only one perforation case out of 3,000 colonoscopic procedures carried out.

While the article has seemingly pointed out such incident should not have happened—these prevalence rates, however, raise question marks over its comparability.

Prevalence for perforation during colonoscopy differs among IBD and non-IBD patients

In general, it is true that colonoscopy tends to be considered a low-risk procedure. According to a computer-based retrospective analysis conducted by Mayo Clinic, only 43 patients (0.075%, or 1 perforation in 1,333 procedures) had a colonic perforation among 57,028 colonoscopic procedures performed.

Another retrospective review published in 2008 also disclosed that colonoscopic perforation occurs in fewer than 1 in 1000 patients. Of the patients with colonoscopic-related perforation (CRP), 61% had undergone a previous abdominal operation. Altogether, 16% of patients underwent colonoscopy with a therapeutic intent (dilation, stenting, and known polyp); whereas the remaining 84% underwent diagnostic procedures.

Nevertheless, these do not mean that carrying out colonoscopies for inflammatory bowel disease (IBD) patients are equally at low risks. According to the report, Cheung suffers from ulcerative colitis, which is one of the most common types of IBD.

A research conducted by the Cleveland Clinic Foundation in the United States has revealed a much higher risk of colonic perforation in the IBD group (1% in IBD hospitalisations) than the control group—even after adjusting for age, gender, comorbidities and endoscopic interventions; including endoscopic dilations and colonoscopic polypectomy.

This percentage also aligns with the statement made by the affected doctor in the report, who commented such incident is not rare and occurs in approximately every 100 cases.

The difference between medical risks and malpractice

“This happened to me when there are so many people, including the elderly patients, undergo colonoscopies every day and are completely fine after that…” Cheung expressed his frustration. He suspected the doctor carried out the procedure with ‘poor techniques’ due to heavy workload at public hospitals.

Although the prevalence for perforation during colonoscopy is small, patients should not neglect the underlying medical risks.
Although the prevalence for perforation during colonoscopy is small, patients should not neglect the underlying medical risks.

Despite the frustration, patients should understand any medical procedures incur certain risks—regardless of the level of risks. Patients should also understand whether the unfortunate incident is resulted from medical risks or clinician’s malpractice.

Of equal importance, healthcare professionals also need to ensure they have clearly conveyed the risk factors and possible complications behind each procedure to the patients, prior to carrying out the operation. MIMS

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