# Prevalence of Liver Dysfunction After One-Anastomosis Gastric Bypass: A Systematic Review and Single-Arm Meta-analysis

## TL;DR

This study finds that a small but notable percentage of patients develop liver dysfunction after a type of weight-loss surgery called one-anastomosis gastric bypass.

## Contribution

The first systematic review and meta-analysis quantifying the prevalence of liver dysfunction after one-anastomosis gastric bypass.

## Key findings

- The pooled prevalence of liver dysfunction after OAGB was 1.2% with high heterogeneity among studies.
- No significant contributors to the heterogeneity were identified in subgroup analyses.
- The study highlights the need for postoperative liver function monitoring despite the low prevalence.

## Abstract

One-anastomosis gastric bypass (OAGB) has gained popularity as a bariatric operation due to its shorter operation time and lower perioperative complication rates, compared with Roux-en-Y gastric bypass (RYGB). However, OAGB is associated with short and long-term complications. Notably, in some reports a subset of patients developed liver dysfunction after OAGB, in some cases causing death or requiring liver transplantation.

A systematic review and meta-analysis were conducted following PRISMA guidelines. MEDLINE, EMBASE and PubMed databases were searched for studies published from 1946 to June 2024, focusing on the prevalence of liver dysfunction post-OAGB. Data extraction and quality assessment were performed by two independent reviewers. Statistical analysis includes pooled prevalence estimates, subgroup analysis against biliopancreatic limb length and regions of the included studies, sensitivity analysis and public bias assessment by Egger’s test.

Of the 3223 identified articles, 7 studies met the inclusion criteria, involving 2944 patients, with 91 patients developing liver dysfunction post-OAGB. The pooled prevalence of liver dysfunction was 1.2% (95% CI 0.3–2.1%), with significant heterogeneity (I2 = 88.5%, p < 0.001). Subgroup analyses did not identify contributors to the heterogeneity. Sensitivity analysis validated the robustness of the findings, and no publication bias was detected by the Egger’s test.

The prevalence of liver dysfunction post OAGB is low but clinically significant, warranting intense postoperative care and regular liver function monitoring. The lack of extensive data on this topic is a limitation, but as the first study to summarise current evidence, this study provides a foundation for future research.

The online version contains supplementary material available at 10.1007/s11695-025-08219-3.