Accuracy of Magnetically Maneuvered Capsule Endoscopy for Detection of EGV in Patients With Cirrhosis

Cirrhosis is the major cause of liver disease-related morbidity and mortality worldwide. Portal hypertension (PH) is the hemodynamic abnormality in patients with cirrhosis, which is associated with various pathological changes throughout the entire gastrointestinal tract, manifesting as esophagogastric varices (EGV), portal hypertensive gastropathy (PHG), and portal hypertensive enteropathy (PHE). Baveno consensus and other practice guidelines recommended that patients with cirrhosis undergo endoscopic screening for EGV at the time of diagnosis and undergo periodic surveillance endoscopy throughout the whole course of cirrhosis. Esophagogastroduodenoscopy (EGD) is recognized as the gold standard for detection and follow-up of EGV in cirrhotic patients, allowing for direct mucosal visualization and therapeutic intervention. EGD is however an invasive procedure and there is potential for procedure-related complications, such as perforation and bleeding. Besides, conscious sedation is always required, leading to increased cost, risk, and inconvenience for the patients.These factors lead to a decrease of patient compliance as well as the effectiveness of the screening program. The capsule endoscopy (CE) system provides a noninvasive and relatively comfortable approach to visualize the GI tract, and the development of esophageal capsule endoscopy (ECE) makes it possible to capture clear images of esophagus without the need of sedation. However, the accuracy of ECE is not currently sufficient to replace EGD for the detection and grading for the esophageal varices. Besides, previous studies presented that the sensitivity of ECE for detecting gastric varices (GVs) and PHG varies from 3% to 69%, which denoted ECE was far from a suitable alternative for diagnosing gastric lesions. To overcome these limitations, a new technique, so-called detachable string magnetically maneuvered capsule endoscopy (ds-MCE) was developed. The ds-MCE system consists of two parts: the magnetically maneuvered capsule endoscopy (MCE) system and a transparent latex sleeve with a hollow string. One end of the hollow string is a transparent thin latex sleeve that can be wrapped on the surface of the capsule, and the other end of the string is connected to the syringe. The capsule, which is partially enclosed within the sleeve, can be actively moved in the esophagus through the control of string. In this case, investigator can examine the entire esophageal mucosa several times under real time views. The capsule then can be detached from the string system through injecting air into the hollow string with the syringe after completing the examination of esophagus. The magnetic capsule in the stomach can be accurately controlled through multidimensional rotation and adaptive matching of an external C-arm robot. Previous studies have demonstrated that the diagnostic accuracy of MCE for detecting gastric focal lesions is comparable with that of conventional EGD. Two previously studies of ds-MCE confirmed it was a feasible, safe and well-tolerated method for completely viewing esophagus and stomach, without the need for sedation. Besides, the 8-10h battery life of the ds-MCE enables complete examination of the small bowel, which enables to provide a more comprehensive evaluation of gastrointestinal changes. Considering all these backgrounds, in the current prospective study, the primary aim is to assess the diagnostic performance of the ds-MCE in identifying the presence of EGV in cirrhotic patients, using EGD as the reference standard. The diagnostic accuracy of ds-MCE in detection of high-risk EV, high-risk EGV, EV, large EV, red signs of EV, GV, cardiofundal GV and PHG compared with the EGD will also be assessed. The incidence of PHE in small bowel under ds-MCE, the examination time of ds-MCE and EGD procedures, patient satisfaction assessment and safety evaluation will also be evaluated.