Ultrasound as the imaging method of choice for monitoring the intragastric balloon in obese patients: normal findings, pitfalls and diagnosis of complications.

BACKGROUND: The authors studied ultrasound (U/S) monitoring of the BioEnterics intragastric balloon (BIB) for treatment of moderate obesity by describing normal U/S aspects, diagnostic pitfalls and assessment of complications.
METHODS: Over the last 3 years, 151 BIB systems have been endoscopically placed and filled with 500-700 ml of saline plus 10 ml of methylene blue in 131 patients (mean age 38.4 years, range 18-72); males/females 46/85; mean BMI 43.8 kg/m(2)). In all patients abdominal U/S was carried out before and 12 days after endoscopy and thereafter at scheduled follow-up examinations, and/or whenever the subject complained of epigastric burning/ache, vomiting, and lack of sensation of a BIB with or without staining of urine and/or feces.
RESULTS: The BIB appeared as a round anechoic structure, with a thick hyperechoic wall and a hyperechoic band-like valve inside. Complications occurred in 18 patients: in 8, staining of urine and/or feces prompted immediate endoscopic removal. In 10 patients, U/S findings were: 1) decreased volume, loss of the spherical shape with the valve still visible (5 cases); 2) multiple hyperechoic streaks regularly spaced due to a completely collapsed BIB, not modified by decubitus changes (3 cases); 3) migration through the intestine (2 cases): in one patient the BIB was passed in the stools after 4 days, whereas in the other case large bowel obstruction required laparoscopic surgery.
CONCLUSION: U/S affords a quick, safe and accurate method for assessing both BIB status after endoscopic deployment and the most frequently-occurring complications (partial/complete deflation, migration through the pylorus with intestinal obstruction) in obese patients.