Study design and population

This was a pilot, prospective, comparative, double-blind, noninferiority study carried out from January to November 2020. During that period, all patients selected for bariatric surgery at our university hospital were asked to undergo an upper gastrointestinal VEC evaluation and an EGD the next day. This sequence was chosen to avoid misinterpretation during VEC of mucosal traumas from an endoscope touching or sucking possible vascular lesions.

Images from each upper gastrointestinal VEC procedure were interpreted by two medical experts, separately and blinded to each other, to reach a higher level of agreement. For the same reason, the data from each EGD ware analyzed by two expert endoscopists, separately and blinded to each other: the first during the endoscopic of the procedure; the second one subsequently, by viewing the recorded file of the procedure.

Finally, the four reports (two from the upper gastrointestinal VEC and two from the EGD) were compared to evaluate the eventual noninferiority of the VEC compared with the EGD, in describing the endoscopic findings diagnosed.

Primary endpoint of the study was to define a noninferiority of upper gastrointestinal VEC compared to EGD in detecting upper gastrointestinal diseases or focal lesions in obese patients prior to bariatric surgery. The secondary endpoint was a comparison of the two procedures in terms of length of stay in the endoscopy room, total amount of drugs used, number of staff members involved, technical problems during the procedures; visual analog scale (VAS) discomfort gradation, and global cost of the procedures.

Inclusion criteria were age between 18 and 65 years, body mass index (BMI) ≥ 35 kg/m ² with obesity-related diseases or BMI ≥ 40, scheduled bariatric surgery intervention, and signing an informed consent.

Exclusion criteria were pregnancy, breastfeeding, use of alcohol/drugs, psychiatric disorders, and patients unwilling to undergo the procedures.

A full and informed consent was obtained from all participants before enrollment. At any time, patients could leave the protocol. All investigations complied with the principles of the Declaration of Helsinki (64th WMA General Assembly, Fortaleza, Brazil, October 2013).