Intrathoracic Pouch Migration after Gastric Bypass: A Systematic Review

Intrathoracic pouch migration (ITM) is an uncommon but increasingly recognized complication after Roux-en-Y (RYGB) or one-anastomosis gastric bypass (OAGB), often associated with hiatal hernia. This systematic review summarizes incidence, clinical presentation, diagnostic modalities, management strategies, and risk factors for recurrence.

This systematic review followed PRISMA guidelines and was registered on PROSPERO. A comprehensive search of PubMed, Embase, Scopus, and Web of Science through November 2025 identified full-text studies on ITM after RYGB or OAGB. Eligible studies reported quantitative clinical, diagnostic, or surgical outcomes; non-relevant designs were excluded.

From 2,343 records, seven observational studies met the inclusion criteria (one prospective, six retrospective). ITM commonly presents with gastroesophageal reflux disease (GERD), dysphagia, abdominal pain, nausea, or vomiting. Reported ITM detection rates ranged from 15% to 76%; however, these estimates were largely derived from selected cohorts undergoing evaluation for recurrent weight gain or hiatal hernia repair and often involved systematic imaging, which may reflect radiologic detection rather than true clinical incidence. CT—especially 3D volumetry—and swallow MRI outperformed endoscopy diagnostically. Simple hiatal repair showed high recurrence (up to 100%), whereas mesh reinforcement and ligamentum teres hepatis augmentation significantly reduced recurrence. Longer migration length and repair type predicted recurrence. Surgical repair improved symptoms in most patients, and ITM was consistently associated with GERD.

ITM is an increasingly recognized complication after OAGB and RYGB, often associated with GERD and functional symptoms. Evidence is limited and observational. Routine hiatal hernia repair is not supported; selective, anatomy-driven strategies, particularly hiatoplasty with ligamentum teres augmentation in revisional cases, appear to reduce recurrence.