Randomized trial of standard versus magnetic endoscope imaging colonoscopes for unsedated colonoscopy

Veterans Affairs Medical Center, University of California San Francisco, San Francisco, California, USA.
Gastrointestinal endoscopy (Impact Factor: 5.37). 02/2012; 75(5):1031-1036.e1. DOI: 10.1016/j.gie.2011.12.030
Source: PubMed


Unsedated colonoscopy has potential benefits, including decreased costs and decreased risks.
To determine whether patient comfort during unsedated colonoscopy can be improved through the use of a magnetic endoscopic imaging (MEI) colonoscope compared with a standard colonoscope.
Prospective, patient-blinded, randomized, controlled trial.
San Francisco Veterans Affairs Medical Center.
Veterans undergoing outpatient screening or surveillance colonoscopy.
Use of a standard or MEI colonoscope during unsedated colonoscopy.
The primary outcome variable was patient perception of pain using a 7-point scale. The secondary endpoint was patient willingness to undergo a future unsedated colonoscopy.
Of the 160 patients enrolled, 140 completed an unsedated colonoscopy in the study protocol. In a per-protocol analysis, the mean and median pain score was 3.12 (standard deviation 1.22) and 4 (interquartile range 2-4) for the standard colonoscope group and 3.06 (standard deviation 1.13) and 3 (interquartile range 2-4) for the MEI group, where 3 was mild pain (P = not significant). Overall, 80% of subjects were willing to undergo a future unsedated colonoscopy for screening or surveillance. In an intention-to-treat analysis, 80% of subjects (64/80) in the standard colonoscope arm and 79% in the MEI arm (63/80) were willing to undergo a future unsedated colonoscopy (P = not significant).
Single-center study of mostly male veterans.
This patient-blinded, randomized, controlled trial did not demonstrate any difference in patient perception of pain or willingness to undergo unsedated examinations when using the MEI versus the conventional colonoscope. Unsedated colonoscopy is generally feasible and well tolerated and is associated with high patient satisfaction rates.

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  • Gastrointestinal endoscopy 05/2012; 75(5):1037-1039.e1. DOI:10.1016/j.gie.2012.02.058 · 5.37 Impact Factor
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    ABSTRACT: The explanation why water exchange colonoscopy produces a significant reduction of pain during colonoscopy is unknown. A recent editorial recommended use of magnetic endoscope imaging (MEI) to elucidate the explanation. In unselected patients to show that MEI documents less frequent loop formation when water exchange is used. Observational, performance improvement. Veterans Affairs outpatient endoscopy. Routine colonoscopy cases. Colonoscopy using air or water exchange method was performed as previously described. The MEI equipment (ScopeGuide, Olympus) with built-in magnetic sensors displays the configuration of the colonoscope inside the patient. During sedated colonoscopy the endoscopist was blinded to the ScopeGuide images which were recorded and subsequently reviewed. Loop formation based on a visual guide provided by Olympus. There were 41 and 32 cases in the water exchange and air group, respectively. The sigmoid N loop was most common, followed by the sigmoid alpha loop, and exaggeration of scope curvature at the splenic flexure/transverse colon. Of these, 20/32 vs. 9/41 patients (p=0.0007) had sigmoid looping, and 17/32 vs. 9/41 patients (p=0.0007) had sigmoid/splenic looping when the scope tip was in the transverse colon, in the air and water exchange group, respectively. Colonoscopy method was not blinded and non randomized. MEI data objectively demonstrated significantly fewer loops during water exchange colonoscopy, elucidating its mechanism of pain alleviation - attenuation of loop formation. Since MEI feedback enhances cecal intubation by trainees, the role of MEI combined water exchange in speeding up trainee learning curves deserves further evaluations.
    07/2012; 2(3):142-146. DOI:10.4161/jig.23738
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    ABSTRACT: A proof-of-principle randomized controlled trial (RCT) evaluated a novel water exchange method in scheduled unsedated veterans. Insertion was conducted with deliberate caution to obviate avoidable discomfort. Despite favorable patient outcomes, the prolonged insertion time was deemed a hurdle to widespread adoption of the method in busy practice models. Using the subsequently time-tested method we reassessed the impacts of water exchange. This was a prospective, RCT (NCT01383252) conducted at an outpatient endoscopy suite at the Sacramento VAMC. 100 consecutive veterans who requested scheduled unsedated screening colonoscopy were randomized to water exchange vs. air method to aid insertion. The main outcome measurements were demographic, patient and procedure-related variables. 90 of 100 randomized patients requested scheduled unsedated colonoscopy due to lack of escort. Intention-to-treat cecal intubation rate was 98% (water) vs. 88% (air), p=0.2687. During insertion there was a significantly lower mean (SD) maximum pain score 3 (2.8) vs. 5 (3.0) (p=0.0008) in the water exchange group. Willingness to repeat: 76% vs. 48% (p<0.0007, Fisher's exact test) was superior with water exchange. Insertion times (min) were comparable 13 (6.7) (water) vs. 12 (7.0) (air) (p=0.4673). Overall (54% vs. 48%), proximal (40% vs. 28%) and proximal <10 mm (36% vs. 28%) ADR were in favor of water exchange. Single VA site, predominantly male patients and unblinded examiners. Relevant to concerns in busy practice models, when the established and time-tested water exchange method is used, the favorable impacts on patient-centered outcomes are no longer at the expense of excessively prolonged procedural times.
    01/2013; 3(1):7-11. DOI:10.7178/jig.100
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