Colonoscopy practice and polyp detection in Nigeria: A systematic review

Evaluation of colorectal pathologies by colonoscopy is increasingly reported from different centers across Nigeria. However, a comprehensive review of current colonoscopy practice across the country is yet to be documented. To report on colonoscopy practice, the detection rate, site(s), and geographic distribution of colorectal polyps in Nigeria, a systematic search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The search databases comprised MEDLINE, African Journal Online, and Google Scholar. The eligibility criteria included publications on flexible lower gastrointestinal endoscopies (LGIEs) performed on Nigerian population over a 20-year period from January 2002 to 2022. Relevant data on study characteristics, demographics of study patients, indication(s), complications of polypectomy, quality metrics for colonoscopy, polyp morphology size, location, and histopathology were extracted and analyzed. Twenty-one observational studies were included comprising 5821 patients who underwent LGIE with an age range of 2–101 years and an M: F of 1.8:1. The polyp detection rate (PDR) was 8.5% in North-West Nigeria, and the mean value ranged from 11.3% [95% confidence interval (CI) 7.0–15.6] in South-West Nigeria to 38.0% (95% CI 165.3–241.3) in South-South Nigeria. The rectosigmoid segment had the highest frequency of polyps [43% (358/828)], and adenomatous, inflammatory, hyperplastic, and malignant polyps were the frequent histology reported: 221 (26.7%), 174 (21.0%), 38 (4.6%), and 13(1.6%), respectively. Summarily, a large disparity exists in PDR among endoscopists in Nigeria. The training of Nigerian endoscopists on techniques to enhance caecal intubation rate, polyp detection, and comprehensive documentation of quality metrics in colonoscopy studies are recommended.