Water Method for Colonoscopy in Sedated Patients is Easy to Learn for an Experienced Colonoscopist and May Minimize the Need for Technical Assistance

Abstract

Purpose: There is recent renewed interest and encouraging results in the use of water infusion as the primary modality for cecal intubation. The technique, however, may be perceived as cumbersome for experienced endoscopists with a high cecal intubation rate using air. Aim: 1) to determine the “learning curve” for the use of water infusion; 2) to identify the major components of the learning curve; 3) to compare cecal intubation time and adenoma yield to historical controls using air insufflation. Methods: In consecutive patients undergoing colonoscopy the procedure was started without air insufflation. Water (at room temperature) was infused through the colonoscope using a pedal pump. The water infusion was used to distend and find the lumen and, to exchange “dirty” for clean water. If air had to be used and the cecum had not been reached, the study was deemed unsuccessful based on an intention to treat (ITT) analysis but the procedure was continued aiming to reach the cecum. Outcomes measured: rate of successful cecal intubation with water method, cecal intubation-, withdrawal- and total- times and adenoma yield. Historical controls (113 consecutive colonoscopies performed by FCR using conventional air insufflation during a prior 3 month period) were used for comparison. Results: A total of 45 consecutive sedated patients were examined using water infusion over a 3-week period.The mean age was 59 years; all were men and 64.4% were for screening. The success rate in the first 20 cases was 70% and in the next 25, 92% based on ITT. 100% of the cecum was reached. Of the 8 “unsuccessful” patients: 3 were truly technically difficult, 4 had the cecum incorrectly identified and in 1 the purge was poor. Time to the cecum was significantly longer than controls (Table 1). The adenoma yield with the water infusion method (38.1% patients) was similar to controls (41.6%). A major component of the learning curve is recognition of the appendiceal orifice. We noted that readily apparent suction marks were consistently observed in the cecum when the appendiceal orifice was not readily seen. Patients undergoing successful cecal intubation with water infusion scarcely required change in their position (n=1) or the need for external pressure (n=2) to guide the scope.TableConclusion: In sedated patients examined by an experienced colonoscopist, the water infusion technique: 1) has a learning curve that is easily achievable; 2) is associated with significantly longer (albeit 3 minutes) cecal intubation time; 3) has an adenoma yield similar to historical controls; 4) may decrease the need for assistant's involvement during the procedure. Whether full mastery of this easy-to-learn approach will enhance adenoma detection deserves to be evaluated.