IntroductionNearly 15% of patients after laparoscopic antireflux surgery experience recurrence of symptoms or develop new gastrointestinal symptoms. Some of them require redo procedures. It can be demanding to reveal anatomical failure after previous fundoplication.AimTo present a method which assists in recognition of anatomical failures after Nissen fundoplication.Material and methodsFive patients with previous laparoscopic Nissen fundoplication and severe gastrointestinal symptoms were included in this study. During the esophagogastroduodenoscopy (EGDS) two radiopaque metal clips were placed to mark the Z-line (“clips-marked Z-line” – CMZL). It was done to achieve precise visualization of the gastroesophageal junction area in the video contrast investigation. Distinctions between conclusions after the EGDS, ordinary video contrast investigation, video contrast investigation with CMZL and intraoperative findings were analyzed.ResultsAll patients underwent laparoscopic refundoplication with good postoperative results. There were 4 cases misdiagnosed by contrast investigation without clips and four cases misdiagnosed by EGDS. Endoscopic clipping helped to recognize correctly all anatomical failures.ConclusionsApplying CMZL as a routine investigation before redo fundoplication can reduce frequency of misdiagnosis and help to perform redo fundoplication in appropriate patients, but it requires further studies on larger cohorts of patients.