Noninvasive vascular assessment of dumping syndrome. Usefulness in therapeutic decisions

Dumping syndrome: pathophysiology and treatment

Anatomic and physiologic changes introduced by gastric surgery result in clinically significant dumping syndrome in approximately 10% of patients. Dumping is the effect of alteration in the motor functions of the stomach, including disturbances in the gastric reservoir and transporting function. Gastrointestinal hormones play an important role in dumping by mediating responses to surgical resection. Treatment options of dumping syndrome include diet, medications, and surgical revision. Poor nutrition status can be anticipated in patients who fail conservative therapy. Management of refractory dumping syndrome can be a challenge. This review highlights current knowledge about the mechanisms of dumping syndrome and available therapy.

Measurement of superior mesenteric artery flow by means of Doppler ultrasound in early dumping syndrome

OBJECTIVE

Dumping occurs in about 10% of patients after gastric surgery. It has been suggested that early dumping is associated with an abnormal increase in postprandial splanchnic flow, but data from controlled studies are lacking. Therefore we have studied basal and postprandial superior mesenteric artery (SMA) blood flow in patients with dumping and in two control groups.

METHODS

Three groups were studied, one group of patients after gastric surgery with early dumping (n = 6), one surgical control group with patients after gastric surgery without dumping symptoms (n = 7), and a healthy control group without previous gastric surgery (n = 10). Blood glucose and heart rate were measured after dumping provocation by oral ingestion of 50 g glucose. SMA blood flow was measured both basally and 20 min after glucose ingestion.

RESULTS

Basal SMA flow was similar in the three groups. After glucose ingestion SMA flow was not significantly different between dumping patients and surgical controls. However, stimulated SMA flow in both groups after gastric surgery combined was significantly (p < 0.05) higher than in healthy controls.

CONCLUSION

The systemic symptoms associated with early dumping do not result from increased SMA blood flow per se. After gastric surgery patients have an increased postprandial SMA flow irrespective of the presence of dumping.

Increased flow in the superior mesenteric artery in dumping syndrome

Transcutaneous Doppler ultrasound was used to measure resting and postprandial blood flow in the superior mesenteric artery (SMABF) in nine patients with dumping syndrome and in ten normal volunteers of matching age and sex. All nine patients experienced signs and symptoms of dumping during the investigation, but none of the controls did so. At rest, SMABF in the dumping patients (567 +/- 47 ml/min) (mean +/- s.e.m.) did not significantly differ from that of the normal volunteers (493 +/- 72 ml/min). Five minutes from the end of a balanced liquid meal, flow had approximately doubled in each group (1232 +/- 140 and 941 +/- 128 ml/min). Compared with controls, increased SMABF was observed in patients with dumping syndrome at 10 min (76 per cent), 15 min (66 per cent), 30 min (55 per cent) and 45 min (42 per cent) (P = 0.05-0.01). Splanchnic pooling and abnormal redistribution of blood probably contribute to the pathogenesis of the early dumping syndrome.