SAGES-EAES systematic review and meta-analysis for the use of FLIP/impedance planimetry in the surgical work-up and management of GERD, achalasia, and gastroparesis.

BACKGROUND

Despite adoption of functional lumen imaging probe (FLIP) technology in foregut surgery, its diagnostic performance and clinical utility remain uncertain. This systematic review and meta-analysis evaluated FLIP in achalasia screening, anti-reflux surgery, myotomy, and gastroparesis to inform a clinical guideline from the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) and the European Association of Endoscopic Surgery (EAES).

METHODOLOGY: A systematic review was conducted through June 24, 2025, addressing four key questions (KQs): (1) preoperative FLIP versus high-resolution esophageal manometry (HRM) prior to anti-reflux surgery; (2A) intraoperative FLIP versus standard technique alone during anti-reflux surgery; (2B) intraoperative FLIP versus standard technique alone during myotomy; and (3) preoperative FLIP versus standard care alone before pylorus-directed therapy for gastroparesis. Comparative observational studies were included, and meta-analyses were performed when appropriate. Certainty of evidence (CoE) was assessed using GRADE; reporting followed PRISMA 2020.

RESULTS

For achalasia screening prior to anti-reflux surgery (KQ1), FLIP likely has high sensitivity (1.00; 95% CI, 0.98-1.00) but may have low specificity (0.52; 95% CI, 0.38-0.66). Preoperative FLIP may improve patient comfort and reduce diagnostic interval. During anti-reflux surgery (KQ2A), intraoperative FLIP may result in little to no difference in dysphagia, reflux recurrence, gas bloating, or quality of life. During myotomy (KQ2B), intraoperative FLIP may increase symptom resolution (OR: 3.45 [95% CI: 1.09, 10.93]) with little to no difference in postoperative GERD or reoperation/revision. No comparative studies were identified for KQ3.

CONCLUSIONS

FLIP may be a highly sensitive and well-tolerated screening tool for achalasia prior to anti-reflux surgery but may have low specificity, and evidence on long-term outcomes is limited. Intraoperative use may improve outcomes during myotomy but may offer limited benefit in anti-reflux surgery. Evidence for gastroparesis-related applications is insufficient. Overall CoE is low to very low, highlighting the need for rigorous, prospective comparative studies.