The Role Of Polyethylene-glycol In Bowel Preparation Before Small Bowel Video Capsule Endoscopy

Aims:As a non-invasive and convenient method of examination,video capsule endoscopy(VCE)has greatly improved the diagnosis rate of small intestine diseases.It is the firstline examination of intestinal diseases recommended by the guideline at home and abroad,especially for of gastrointestinal bleeding with unknown causes.The clean field of vision plays a crucial role in the diagnosis of small intestine disease in VCE.In this study,the network meta-analysis(NMA)was used to analyze the current research to find the optimal dose of polyethylene-glycol(PEG),and furtherly,the optimum time and dose of PEG before VCE examination were explored through a randomized controlled study.Methods:1.According to the randomized controlled studies of the bowel preparation before VCE using PEG searched by PubMed,Cochrane Library and Embase databases,the direct and indirect comparison of small bowel visualization quality,diagnosis rate and total small intestine examination completion rate of different preparation were completed by NMA.And furtherly,the rank of different PEG doses was completed by the surface under cumulative ranking(SUCRA),to obtain the optimal dosage of PEG.2.This study was a multicenter,single-blind,randomized,controlled trial of 410 patients undergoing VCE.Patients were randomly divided into 5 groups:group A didn’t take PEG solution before examination,group B took 1L PEG solution 12 hours before examination,group C took 2L PEG solution 12 hours before examination,group D took 1L PEG solution 4 hours before examination,Group E took 2L PEG solution 4 hours before examination.All subjects fasted for 12 hours prior to the test and took 8 ml simethicone with 250 ml fresh water 30 minutes before the test.The primary endpoint of this study was the cleanliness of the small intestine.The secondary endpoint was the patient’s acceptance of the bowel preparation and the diagnostic yield of VCE.Results:1.Small bowel visualization quality was significantly improved in patients who completed bowel preparation with PEG compared with those in the control(Fast)group(274/382(71.7%)and 178/334(53.3%),OR(95%CI)=2.56(1.83-3.59),Z=5.48,P<0.001).The SUCRA of each group was 89.4%for PEG 2L,62.5%for PEG 1 L,44.0%for PEG 4 L and 4.1%for the control(Fast)group.2.The distribution among the groups of the subjects with"excellent"small bowel visualization quality was as follows:27 in Group A,38 in Group B,40 in Group C,55 in Group D,43 in Group E.The cleanliness of small intestine was significantly improved in group D compared with group A(66.3%vs.32.5%,P<0.001).The analysis of intestinal contamination revealed a significant reduction of food debris in the distal intestine in group D(P<0.001).The use of 1L PEG did not affect the acceptability of patients(P>0.005)and no effect of diagnosis yield(P=0.212)was found.Conclusions:Taking 1L PEG 4 hours prior to VCE can improve small bowel visualization quality by reducing food debris in the distal segment of the small intestine,making it an ideal method of bowel preparation.