Second-generation Versus First-generation Magnetically Controlled Capsule Gastroscopy for Upper Gastrointestinal Tract: a Randomized Controlled Clinical Trial.
Phase: NA
Conditions: Capsule Endoscopy
Sponsor: Changhai Hospital

Second-Generation Magnetically Controlled Capsule Gastroscopy with 
Improved Image Resolution and Frame Rate: Study Protocol for A 
Randomized Controlled Clinical Trial 
 
Document Date: February 1st, 2019. 
Trial registration: ClinicalTrials.gov ID: NCT03977935 
 
 
INTRODUCTION 
Magnetically controlled capsule gastroscopy (MCCG) provides good visualization of the stomach, and 
is highly accepted due to the characteristics of painlessness, noninvasiveness and favorable diagnostic 
accuracy as conventional endoscopy1,2. However, the upper gastrointestinal (UGI) tract under capsule 
endoscopy (CE) continues to present challenges including rapid transit through esophagus and 
duodenum3,4, as well as longer gastric examination time5 compared to conventional endoscopy. 
Technical improvements in frame rate, field of view, dual camera, image resolution and battery life 
have been performed to optimize the clinical application of CE, and some turned out to be 
effective6,7,8,9. 
Therefore, a new-generation MCCG (MCCG-2) highlighted with a higher and adaptive frame rate of 
8 frames per second (fps), better image resolution of 720 x 720 pixels, wider field of view of 150°, 
extended battery life of more than 12 hours and anti-jamming wireless data transmission has been 
developed. Hence, this pilot study was conducted to determine whether MCCG-2 can further optimize 
the visualization of UGI tract, thus result in better diagnosis of UGI diseases. 

METHODS 
Study design 
This pilot study was a prospective, single-centered, blinded randomized controlled study, approved by 
the institutional review board of Shanghai Changhai Hospital and registered at ClinicalTrials.gov. with 
registration number NCT03977935. Written informed consent was obtained from each enrolled subject.  
Patients 
From May 2019 to June 2019, 80 consecutive patients aged 18-80 years with or without abdominal 
complaints referring for MCCG examination were prospectively enrolled and randomly allocated into 
MCCG-1 group or MCCG-2 group a 1：1 ratio. Patients with any of the following contraindications 
for MCCG were excluded: pacemakers or electromedical devices implanted which are incompatible 
with magnetic field; suspected or known gastrointestinal stenosis, obstruction or other known risk 
factors for capsule retention; scheduled magnetic resonance imaging examination before excretion of 
capsule; pregnancy or suspected pregnancy; and any other contraindications determined by 
endoscopists. 
Study intervention 
The MCCG, a robotic magnetic capsule guidance system, was provided by Ankon Technologies Co. 
Ltd (Shanghai, China). The MCCG system was consisted of a guidance magnet robot, a capsule 
endoscopy, a data recorder and a computer workstation with a software for real-time view and two 
joysticks for capsule orientation control. The guidance magnet robot was of C-arm type with five 
degrees of freedom: two rotational (horizontal and vertical directions) and three translational 
(forward/backward, up/down, left/right).  

After a standardized gastrointestinal (GI) preparation regimen for MCCG, patients were placed in the 
left lateral decubitus position and swallowed MCCG-1 or MCCG-2 with a small amount of water 
according to a random number table with the help of of nurses at the digestive endoscopic center. 
When MCCG reached the stomach, it would be lifted away from the posterior wall, rotated and 
advanced to the fundus and cardiac regions, followed by the gastric body, angulus, antrum and the 
pylorus. During this procedure, position changes such as supine, prone, left and right lateral were also 
helpful in achieving clear observation and smooth transition. Standardized examination procedure of 
MCCG was available online at videogie.org10. Cases with suspected malignancy were rechecked under 
conventional endoscopy. 
Image capture rate in the esophagus and stomach were 2 fps or 6 fps in MCCG-1 or MCCG-2 group, 
and standardized operation of MCCG were performed twice for complete gastric examination. After 
the capsule moved into the duodenum, patients left the hospital with the data recorder to continue with 
small-bowel examination. In the small bowel, MCCG-2 offered an adaptive frame rate technology 
which adjusted the image capture rate based on how fast the capsule was moving.  
Study outcomes and definition 
Basic characteristics of the enrolled patients were prospectively collected. Primary study outcome was 
efficacy analysis including visualization of the esophagus and duodenum indicated by detection rate 
of Z-line and duodenal papilla defined as at least one image of Z-line or duodenal papilla was obtained, 
the number of images captured for esophagus and Z-line, circumferential visualization of Z-line as the 
number of quadrants observed and cleansing level of Z-line as bubbles/saliva on Z-line11. Operation 
related parameters included esophageal transit time (ETT), gastric examination time (GET), gastric 
transit time (GTT), small bowel transit time (SBTT) and total running time (TRT). Image quality, 

maneuverability and detection of lesions were also prospectively documented. Any procedure related 
adverse events were closely recorded.  
GET was defined as the time for examination of gastric primary anatomical landmarks twice. Image 
quality ranged from one to ten denoting from the worst to the highest12. Maneuverability was classified 
as fluency (the response to operation and video effect), stability (the ability of holding the capsule at 
one position for at least one minute) and comfortableness (the operator’s fatigue degree during the 
examination), and each index graded from one to five with one as the worst and five as the best. 
All examinations and maneuverability evaluation were performed by an endoscopist (W.Z.) with an 
experience of more than 1000 cases of MCCG operation. Two other endoscopists blinded to the 
grouping would independently evaluated the image quality with a mean value as the final score, and a 
third endoscopist would make the final judgement when there existed a discrepancy more than three. 
The randomization schedule was generated by the investigator using a random number table, making 
it possible that patients enrolled and endoscopists involved were all blinded to the treatment protocol 
assigned. 
Statistical analysis 
As a pilot study to evaluate the clinical utility of MCCG-2, sample size was not calculated for this 
study. Quantitative data were summarized with parametric statistics, mean and standard deviation, or 
with nonparametric statistics, median and interquartile range, whereas categorical data were presented 
as frequency (percentage). Data with a normal distribution were compared using parametric analysis 
and non-normally distributed data were compared using nonparametric statistical analyses. Categorical 
variables were analyzed with the χ2 exact test and quantitative data were analyzed using the Mann–

Whitney Wilcoxon test with a final two-sided P value of less than 0.05 indicating statistical difference. 
SPSS 13.0 software was used.  
 
 
Central contact： 
Zhuan Liao 
National Clinical Research Center for Digestive Diseases; Department of Gastroenterology, 
Changhai Hospital, 168 Changhai Road, Shanghai 200433, China 
Tel: 86-21-31161004 
Fax: 86-21-65492727 
E-mail: liaozhuan@smmu.edu.cn 
 
 
Disclosures: The authors declared no conflict of interest. 
 
Acknowledgement: None. 
 
 
 
 
 
 

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