technetium-tc-99m-sulfur-colloid and Obesity--Morbid

Radionuclide studies of the upper gastrointestinal tract have been useful in many gastrointestinal disorders. However, the literature relating to radionuclide techniques in morbid obesity is limited and, at times, controversial. It is hoped that this brief review will stimulate interest in the use of tracer techniques in this complex disorder.

Topics: Biliary Tract; Esophagus; Gastric Emptying; Humans; Indium Radioisotopes; Obesity, Morbid; Pentetic Acid; Postoperative Care; Radionuclide Imaging; Technetium Tc 99m Sulfur Colloid

As a result of the intrapleural pressure gradient that exists in the human lung, both ventilation and particle deposition increase from apex to base. Since the intrapleural gradient varies with the height of the subject, it was decided to compare regional particle deposition in tall, short, and obese subjects to ascertain whether it was influenced by height and weight. Surprisingly, deposition in the vertical plane was not significantly influenced by the height of the subject when corrected for ventilated lung volume. In addition, it was shown that in obese subjects there was increased deposition in the middle zones relative to the apices and bases. This finding persisted after correction for ventilated lung volume and differential attenuation resulting from non-uniform thickness of the fat layer in the obese subject's chest. In the tall and short groups there was a consistent pattern in the concentric deposition of particles with there being a gradient from the central or hilar region to the periphery of the lungs, with the latter showing the most deposition.

Topics: Adipose Tissue; Adult; Aerosols; Body Constitution; Body Height; Female; Humans; Lung; Male; Obesity, Morbid; Particle Size; Respiration; Technetium Tc 99m Sulfur Colloid; Trachea; Xenon Radioisotopes

The Garren-Edwards Gastric Bubble (GEGB) was introduced in 1984 as an alternative to surgery (jaw wiring, gastrointestinal bypass, vertical banded gastroplasty) for the treatment of morbid obesity in patients who had failed behavior modification therapy or dietary management for weight reduction. Its mechanism of action is unclear and previous reports have not demonstrated any significant consistent alteration in gastric emptying (GE) as measured by radionuclide techniques. Other proposed mechanisms include: placebo, hormonal, mechanical "satiety", behavioral modification, and neuronal. In order to determine the effect of the GEGB on GE, ten obese (mean % overweight = 89%) patients, 27-50 yr old (mean = 36 yr), had solid GE scans before and 5 wk after endoscopic placement of the bubble. GE scans were performed in six patients after removal (12 = wk residence time). The meal consisted of 300 microCi [99mTc]sulfur colloid in the form of a 300 kcal egg sandwich (egg white 248 g, white bread 40 g, butter 6 g; composition = CHO 40:PR 40: FAT 20) with 180 ml deionized water. Images were obtained in the anterior and posterior projections at 15-min intervals for 1 hr (four patients) or 2 hr (six patients) and the %GE (decay corrected geometric mean) was calculated. Unlike other studies involving the GEGB, adjunctive therapy in the form of dieting and behavior modification were not employed in this study. The effect of the GEGB alone in the treatment of obesity has not been previously evaluated. There was a significant (p less than 0.025) delay in gastric emptying at 1 hr (pre-bubble mean % gastric retention = 46%; bubble mean = 57%; n = 10). After removal, GE returned toward baseline (mean % gastric retention = 51%; n = 6) (p less than 0.05) (Student's t-test). The average weight loss was 5.5 lb (n = 10; p less than 0.025). One mechanism of action of the GEGB may be delayed gastric emptying resulting in early satiety and decreased food intake with resultant weight loss.

Topics: Adult; Evaluation Studies as Topic; Female; Gastric Emptying; Humans; Middle Aged; Obesity, Morbid; Prostheses and Implants; Radionuclide Imaging; Stomach; Technetium Tc 99m Sulfur Colloid; Weight Loss

Dual isotope gastric emptying studies were performed on 16 morbidly obese patients before and after gastroplasty to determine the effect of this surgery on the rate of emptying. The solid and liquid phases of gastric emptying were compared with a normal control group. In the 900-g and 50-g meals there was a significant difference in the mean half emptying time between solid and liquid phases of emptying (p less than 0.05). Pre-operatively, the 900-g meal half emptying times of both solids and liquids and the 50-g liquid phase meal did not differ significantly between obese patients and the control group. However, in the solid phase of the 50-g meal obese patients differed significantly from a control group (p = 0.007). Three months after gastroplasty, gastric emptying of 50-g meals from the total stomach was not significantly changed from the pre-operative 50-g meal values in ten of 12 patients (p less than 0.05) and no change in total stomach emptying times were seen at 12 mo compared to the 3-mo study (p less than 0.05). Emptying of the pouch alone for both solids and liquids was significantly faster than the pre-operative and postoperative total stomach studies. Gastric emptying in the obese is normal with large meals, but is delayed in small meals. In most patients, gastroplasty does not result in slower emptying of meals.

Topics: Female; Gastric Emptying; Humans; Indium; Male; Obesity, Morbid; Pentetic Acid; Radioisotopes; Stomach; Technetium Tc 99m Sulfur Colloid