The effect of gastric banding on body weight in experimental animals

Recently a new method of gastroplasty has been used in operative treatment of extreme obesity in humans. It depends on putting on the stomach an inabsorbable band in order to form two reservoirs: one small upper, the other large lower, and a narrow passage connecting them, without the necessity to open the stomach. Before using this method on humans it has been experimentally examined on 19 pigs. Gastric banding has little effect on the decrease of body weight, it has some effect only in the first 3-6 weeks. Bands put on the stomach move inside it because of the excessive built-up of pressure in the upper reservoir. The reservoirs vanish. Animals quickly put up weight. The pathological mechanism of moving the band inside the stomach can be explained by the presence of two processes: one reperative, on the serose layer, the other destructive, into the stomach. These findings prove that in operative treatment of extreme obesity in humans it seems essential not to allow the pressure to build up excessively in the upper stomach reservoir.