Multiple sampling 13C-urea breath test: improvement of diagnosis in postgastrectomy patients

Partial gastrectomy and Helicobacter pylori (H. pylori) infection are considered 2 risk factors for gastric cancer development. False negative urea breath test (UBT) results have been described in patients with gastric surgery, due to rapid gastric emptying of urea solution from the stomach. On the other hand, a rapid 10-minute 14C-UBT proved to be highly reliable for diagnosis of H. pylori infection when delaying test meal was omitted. Aim of this study was to improve the diagnostic accuracy of 13C-UBT in patients with gastric resection.

UBT was performed in 100 gastrectomised patients with breath collection at 0, 10, 15, 20, 25 and 30 minutes (multi-UBT) after 100 mg 13C urea ingestion and 100 ml of marketed fruit juice. In 28 cases contemporary histological data from biopsy specimens (within 1 month, in absence of treatment) were also available.

Multi-UBT was persistently negative or positive in all the samplings in 34% and 25% of cases, respectively. Positivity only at 30 minutes was found in 10% of cases, while 19% of subjects were positive at 15-25 minutes but not at 30 minutes. In 12% of cases the test was positive only at 10 minutes.

Multi-UBT offers a not negligible diagnostic improvement over the standard UBT: at least 19%, and up to 31% if positivity at ''10-minute only'' is taken into account. This method can be useful when accurate diagnosis of H. pylori infection is required in gastrectomised patients.