Resolution of MASH with no worsening of fibrosis after bariatric surgery improves 15-year survival: a prospective cohort study.

Objectives: Investigate the consequences of the histological progression of metabolically associated steatohepatitis (MASH) and fibrosis on long-term survival after bariatric surgery.

Methods: From 1994 to 2021, 3028 patients at the University Hospital of Lille were prospectively included. Baseline liver biopsies were systematically performed with proposed follow-up biopsies 1 year after surgery, mainly in MASH patients. We evaluated the association of the baseline and 1-year histological progression of MASH and fibrosis status and long-term survival using Cox regression models.

Results: At baseline, 2641 patients had a biopsy (89%), including 232 with MASH (8.7%) and 266 (10.8%) with significant fibrosis (grade F2-F4). The median follow-up was 10.1 years. At 1 year, 594 patients had qualitative paired biopsies. Survival was shorter at the 15-year follow-up in patients with baseline MASH, than in those without (hazard ratio (HR), 2.21; 95% confidence interval (CI), 1.38 to 3.53) and in F2-F4 than in F0-F1 (HR, 3.38; (95%CI, 2.24 to 5.10). At the 1-year landmark analysis, compared to patients without baseline MASH, mortality increased in those with persistent MASH and/or if fibrosis worsened (adjusted HR, 2.54 (95% CI, 1.06 to 6.10), but not if MASH resolved without the worsening of fibrosis (adjusted HR, 0.73 (95% CI, 0.28 to 1.87). Similarly, compared to patients without significant fibrosis at baseline, patients with persistent significant fibrosis had increased mortality (adjusted HR, 4.03 [95% CI, 1.86 to 8.72]) but not if fibrosis improved from F2-F4 to F0-F1 (adjusted HR; 1.49; 95%CI, 0.52 to 4.24).

Conclusion: Histological remission of MASH or significant fibrosis improves survival after bariatric surgery.