Metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) are common among patients undergoing metabolic and bariatric surgery, yet clinically significant liver disease frequently remains undiagnosed. Our recent study of intra-operative liver biopsy during bariatric surgery highlights an important opportunity for bariatric surgeons to change this.

Preoperative laboratory studies, FIB-4 and other risk calculators, non-invasive imaging, and even visual inspection of the liver by an experienced surgeon may fail to reliably identify MASH or significant fibrosis. Liver biopsy remains the gold standard for establishing an accurate histologic diagnosis and determining the severity of liver disease.

Importantly, obtaining a liver biopsy during bariatric surgery is remarkably practical. In our experience, biopsy adds approximately five minutes to an operation, requires little more than an inexpensive biopsy device, and has a very favorable safety profile. In our study, postoperative complications were not increased among patients undergoing routine biopsy.

The diagnostic yield is compelling. Approximately 32% of patients had MASH and 20% had fibrosis—clinically important abnormalities that might otherwise have gone unrecognized. These diagnoses provide actionable information. Patients with MASH or fibrosis warrant longitudinal surveillance, and selected patients may benefit from hepatology evaluation and emerging pharmacologic therapies directed at MASH and fibrosis. Continued monitoring is also important because these patients remain at increased metabolic and cardiovascular risk.

Metabolic and bariatric surgery itself is among the most effective treatments for obesity-associated MASH and fibrosis. Nevertheless, not every patient achieves complete resolution of liver disease or elimination of cardiovascular risk. Identifying significant disease at surgery establishes an invaluable baseline and identifies patients who deserve closer long-term follow-up.

The economics are similarly favorable. The incremental expense of approximately five minutes of operating time, a low-cost biopsy needle, and histologic interpretation is small when incorporated into an already planned bariatric operation, particularly given the potential value of detecting previously unrecognized disease.

Yet nationally, only 3.5% of bariatric operations include liver biopsy. This represents a substantial missed opportunity. Bariatric surgery offers a unique moment to both treat metabolic disease and accurately characterize one of its most important complications. Surgeons should consider routine—or at least far more liberal—use of intra-operative liver biopsy. Five minutes in the operating room may provide information that influences a patient's care for decades.

Disclosure: The author, Philip R. Schauer, MD, was a co-author of the study discussed in this editorial. The authors of the study reported no relevant financial or nonfinancial disclosures.

Reference: Garcia Navas HJ, Dahlgren N, Bhatia S, et al. Intraoperative liver biopsy during metabolic and bariatric surgery: diagnostic yield, safety, and national trends. Surgery for Obesity and Related Diseases. Published online July 17, 2026. doi:10.1016/j.soard.2026.07.009.