This invention combines three medical-surgical elements such as an intragastric balloon, a valve to control the postoperatory inflating and the technique of percutaneous gastronomy with endoscopic control, as well as a new mean to fix the assembly that avoids the balloon migration. The intragastric balloon assembly of the invention comprises the silicone balloon with an inflating catheter and a device consisting in a silicone bar, which will be used as a tension support and for fixation to the aponeurosis by means of an adjustable plate, according to the needs, that may be secured with suture points or with metallic staples to the aponeurosis. Once such elements have been secured, the support is cut and the catheter is connected to an inflating valve, which in a preferred embodiment is placed in subcutaneously and held in place with suture points or staples to the aponeurosis.