Gastric emptying and postprandial PYY response after biliopancreatic diversion with duodenal switch

Super-obesity (BMI > 50) is increasing rapidly. We use the biliopancreatic diversion with duodenal switch (BPD-DS) as one option in this patient category. The aim of the present study was to investigate the emptying of the gastric tube, PYY levels and dumping symptoms after BPD-DS.

Emptying of the gastric tube was investigated with scintigraphy after an overnight fast. Twenty patients (median age 43 years, BMI 31.1 kg/m²) having undergone BPD-DS in median 3.5 years previously were included in the scintigraphic study. A technetium-labelled omelette was ingested and scintigraphic evaluation of gastric emptying was undertaken. Ten of the patients also underwent PYY measurements after a standardised meal and were compared to nine non-operated age-matched normal weight controls, both in the fasting state and after the test meal. Frequency of dumping symptoms was evaluated in all patients.

The half-emptying time was 28 ± 16 min. Lag phase was present in 30% of the patients. PYY levels were significantly higher in BPD-DS patients as compared to controls both in the fasting state (p < 0.001) and after the test meal (p < 0.001). Dumping symptoms were scarce and occurred in 17 of the 20 patients only few times yearly or less.

Although the pylorus is preserved in BPD-DS, the stomach emptying is faster than in non-operated subjects. PYY levels are elevated in the fasting state after BPD-DS and a marked response to a test meal is seen, likely due to the rapid stimulation of intraluminal nutrients in the distal ileum. In spite of this, dumping symptoms are uncommon.