Bariatric surgery study finds frequent liver abnormalities where biopsy was used

What happened

An observational study compared operations with and without liver biopsy using records from a Louisiana academic bariatric center and a national surgical database. The researchers asked how often biopsy found steatotic liver disease, steatohepatitis, or fibrosis and whether biopsy was associated with postoperative complications.

The local analysis included 980 operations, while the national analysis covered 695,343 cases from 2020 through 2023. Patients were not randomly assigned to receive a biopsy. The analysis excluded people younger than 18, open operations, conversions and revisions, and local cases without biopsy results.

At the Louisiana center, 48% of operations included a liver biopsy. Among the patients who were biopsied, 71.8% had steatosis, 31.6% had steatohepatitis, and 20.6% had fibrosis. Across the national database, 3.5% of bariatric operations included a biopsy.

The local analysis found no statistically clear difference in postoperative complications between operations with and without biopsy. In the national data, cases with biopsy had slightly lower complication estimates, although some small differences met statistical significance because of the very large sample.

What it means

The local findings show that liver abnormalities were common among the patients selected for biopsy at that center. A biopsy taken during an operation can identify fat, inflammation, or scarring that may not have been established before surgery. A confirmed finding may affect follow-up discussions and whether liver-focused care is needed.

The contrast between 48% local use and 3.5% national use also shows that biopsy practice varies widely. The study can inform discussions about diagnostic yield, but the decision to perform a biopsy still depends on the individual patient, the surgeon's assessment, and the risks and benefits of obtaining tissue.

What it does not mean

The study does not prove that every bariatric surgery patient should receive a liver biopsy. Patients were not randomized, and the reasons one patient received a biopsy while another did not may also be related to health status, surgeon preference, center practice, or other factors.

The complication comparison does not prove that biopsy adds no risk. The abstract does not provide every absolute complication rate or long-term biopsy-related outcome. Small differences can also become statistically significant in a database of nearly 700,000 operations without being large enough to change care.

The local percentages are not prevalence estimates for every bariatric program. They reflect one center where biopsy was used much more often than in the national sample and where selection practices and the population served may differ from other centers. The abstract also does not show that finding liver disease led to better long-term outcomes.