Steam ablation of duodenum lining shows promise in reversing type 2 diabetes in early trials

Researchers are testing an endoscopic steam treatment that deliberately damages and then allows regeneration of the duodenal lining as a potential way to improve blood-sugar control and reduce the need for insulin in people with type 2 diabetes.

Early clinical results reported in peer-reviewed journals and conference literature indicate meaningful reductions in glycated haemoglobin (HbA1c) and, in small studies, the ability of some patients to stop insulin injections while continuing or reducing oral therapy.

The technique, variously called duodenal mucosal resurfacing or radiofrequency vapour ablation, involves passing a catheter through an endoscope and delivering brief blasts of hot vapour to the duodenal mucosa. The procedure typically takes about 30 minutes, uses liquid heated to roughly 90°C, and providers report patients are discharged within a few hours and the surface layer heals in about a month.

Investigators say the approach builds on observations from bariatric surgery: patients often experience rapid improvements in blood glucose after gastric bypass that cannot be attributed solely to weight loss. Researchers now believe that a thickened, engorged duodenal lining seen in many people with type 2 diabetes contributes to impaired signalling that worsens blood-glucose regulation. Ablating and allowing regeneration of that surface may restore more normal nutrient signalling and insulin sensitivity.

A multi-centre trial published in Diabetes Research and Clinical Practice in 2022 found that, after two years, patients who underwent duodenal mucosal ablation had significantly reduced HbA1c and that more than half reduced their diabetes medications or kept them constant rather than increasing doses. A smaller, more recent study using a newer vapour ablation device reported in GIE, the journal of the American Society for Gastrointestinal Endoscopy, described 20 patients treated in Chile; nine months after treatment all 20 had stopped insulin injections, though some remained on oral medications.

In a 2023 study overseen by researchers at the private Cleveland Clinic in London and conducted in Chile, clinicians treated a 60 centimetre section of the duodenum — a length chosen to mimic the portion bypassed by gastric bypass surgery. Investigators reported average HbA1c falling from about 9.3% before treatment to roughly 7.6% afterwards. Study leaders said full results from that study are expected to be published next year.

Regulators and guideline bodies have urged caution. The National Institute for Health and Care Excellence (NICE) reviewed evidence on duodenal mucosal resurfacing and recommended the procedure be restricted to formal research settings until larger, longer-term trials establish safety, durability and comparative effectiveness. The treatment is not currently available through routine NHS services in the United Kingdom.

Clinicians involved in the research describe the procedure as minimally invasive. "The patient goes home around two hours later and the lining is healed around four weeks later — so far, patients on the trial have not reported any complications, discomfort or pain," said Dr. Rehan Haidry, a gastroenterologist and interventional endoscopist leading the trial oversight. Arin Saha, a consultant in upper gastrointestinal and bariatric surgery, said the findings echo earlier observations from weight-loss surgery and called further studies "very interesting," adding that a new tool to tackle the growing number of people with type 2 diabetes would be welcome.

Epidemiological context underscores the potential impact: in the United Kingdom an estimated 5.8 million people have a diabetes diagnosis and about one in four with type 2 diabetes uses insulin injections, according to Diabetes UK. Researchers say that if larger trials confirm safety and effectiveness, endoscopic duodenal resurfacing could offer a less invasive alternative to surgery for some patients.

Experts caution that evidence to date comes largely from small trials and short to intermediate follow-up. Important unanswered questions include how long benefits last, which patients are most likely to benefit, and how the procedure compares with existing medical and surgical therapies over the long term. Investigators leading ongoing work are seeking regulatory approval to launch larger trials in the United Kingdom and elsewhere.

Until results from those larger, controlled studies are available, clinicians and guideline bodies advise that the procedure be offered only within formal research protocols so that safety, efficacy and durability can be robustly assessed.