Colonoscopy is commonly used to screen for neoplasia.
Dr Robert Barclay and colleagues from Illinois assessed the performance of screening colonoscopy in everyday practice.
The research team conducted a study of the rates of detection of adenomas and the amount of time taken to withdraw the colonoscope among endoscopists in a large community-based practice.
During a 15-month period, 12 experienced gastroenterologists performed 7882 colonoscopies.
Of these colonoscopies, 2053 were screening examinations in subjects who had not previously undergone colonoscopy.
The researchers recorded the numbers, sizes, and histologic features of the neoplastic lesions detected during screening.
The research team also evaluated the duration of insertion and of withdrawal of the colonoscope during the procedure.
|Mean withdrawal times of 6 minutes or more had a detected 28% of any neoplasia|
|New England Journal of Medicine|
The team compared rates of detection of neoplastic lesions among gastroenterologists.
Gastroenterologists who had mean colonoscopic withdrawal times of less than 6 minutes were compared with those of rates of 6 minutes or more.
According to experts, 6 minutes is the minimum length of time to allow adequate inspection during instrument withdrawal.
The researchers found that neoplastic lesions were detected in 24% of screened subjects.
There were large differences among gastroenterologists in the rates of detection of adenomas.
The team noted that there were large differences among gastroenterologists in their times of withdrawal of the colonoscope from the cecum to the anus.
The researchers observed that this time ranged 3 to 17 minutes for procedures during which no polyps were removed.
Colonoscopists with mean withdrawal times of less than 6 minutes had a detection rate of 12% of any neoplasia.
The team observed that those with mean withdrawal times of 6 minutes or more had a detection rate of any neoplasia of 28%.
The researchers noted that colonoscopists with a mean withdrawal time of less than 6 minutes detected advanced neoplasia at a rate of 3%.
Colonoscopists with a mean withdrawal time of 6 minutes or more detected advanced neoplasia at a rate of 6%.
Dr Barclay's team concluded, “In this large community-based gastroenterology practice, we observed greater rates of detection of adenomas among endoscopists who had longer mean times for withdrawal of the colonoscope.”
“The effect of variation in withdrawal times on lesion detection, and the prevention of colorectal cancer in the context of widespread colonoscopic screening is not known.”
“Ours was a preliminary study, so the generalizability and implications for clinical practice need to be determined by future studies.”