Dual-Isotope Scintigraphy for Gastrointestinal Transit in Duodenal Switch: An Explorative Clinical Study

Biliopancreatic diversion with duodenal switch (BPD/DS) is a highly effective metabolic bariatric procedure. However, the decreased gastric volume and exclusion of small bowel to reduce uptake of fat-soluble nutrients can induce gastrointestinal side effects. The aim of this study was to assess gastrointestinal transit times for bile and food using a novel dual-isotope scintigraphy method and explore associations with gastrointestinal symptoms.

This is an explorative single-center clinical study in 10 patients after primary BPD/DS; 99mTc Bromo-biliaron-labeled bile acid analogue was injected intravenously, 111In-DTPA-labeled omelet was ingested orally, and scintigraphic images were taken every 10 min for 180 min. Gastrointestinal symptoms were scored using the fecal incontinence quality of life (FIQL) questionnaire, and the patients were stratified by stool frequency (≥ 3 stools/day).

All scintigraphic examinations gave interpretable data. FIQL scores of 3.2-3.6 out of 5 demonstrated a clear quality of life impact. Gastric emptying half-time was 40 min. Median time to the enteroenterostomy was 70 min (IQR 55-138) for food and 105 min (IQR 38-148) for bile. In patients with ≥ 3 stools/day, food reached the enteroenterostomy faster than bile (70 vs 115 min), while the opposite was seen in the remaining patients (110 vs 75 min). However, no statistically significant associations between stool frequency and transit times were identified.

Dual-isotope scintigraphy enables assessment of gastric and small bowel transit after BPD/DS. Although transit times were variable, we believe that the novel imaging technique can add valuable information in patients with severe gastrointestinal symptoms.