Colon Adenomas and Cancer Detection Rates: Does the Type of Sedation Matter?

Abstract

Purpose: The utilization of deep sedation is often used for screening colonoscopy (SC). Deep sedation which is the standard for Monitored Anesthesia Care (MAC) in endoscopy improves the quality of sedation and patient satisfaction compared to moderate sedation (MS) using a benzodiazepine and a narcotic. MAC has been shown to improve the technical aspects of colonoscopy, such as reducing patient repositioning or applying abdominal pressure. However, there is very limited data about the effect of MAC use on adenoma and cancer detection rates, which is considered the main measure of quality in SC. To our knowledge, there are two retrospective studies that compared polyps or adenoma detection rates between MAC and MS. One study did not consider exclusively SC but included patients with variable indications. The second study included only SC, but had two limitations: it did not report an accurate histological diagnosis of the polyps and it did not control for any of the factors that affect adenomas detection rates. Aim: Compare colonic adenoma and cancer detection rates between patients undergoing SC under MAC and patients undergoing SC under MS. Methods: Retrospective case-control study. Cases and controls included all SC performed at our institution over the past 5 years, with documented cecal intubation and adequate bowel preparation. The controls were matched to the cases based on age, gender, race, same endoscopist, risk for cancer (average vs. high), timing during the day (am vs. pm), and the presence or absence of a gastroenterology fellow. We counted the number, size and histological features of all polyps and adenomas found in all subjects. Results: 131 cases and their corresponding controls were included (mean age: 57 years; Females: 60%; African-Americans: 70%; High risk: 46%, fellows present: 22%; Morning cases prior to noon time: 82%). The adenoma detection rate was statistically similar between the cases (28.2%) and the controls (25.2%) (p=0.68). Polyps' detection rate was also comparable (cases 42.2% vs. controls 36.7%; p=0.53). In both groups adenomas were more commonly detected in the right colon. The average size of adenomas was 9.3 mm for the MAC cases and 10 mm for the controls. One right-colon cancer was found in the control group but none in the cases group. The detection rate of advanced adenomas found was identical among the two groups (4.5%). Subgroup analysis based on cancer risk is reported in Table 1.Table: Table. Subgroup analysis based on cancer riskConclusion: In the current study, no differences in adenoma detection rates were found between SC done with deep sedation compared to SC done with moderate sedation. We suggest a similar study with a larger sample size to evaluate that matter.