The invention relates to an orogastric catheter for a longitudinal gastrectomy. The object of the invention is to make available an orogastric catheter that represents an advantageous alternative to the poorly suited catheters used today and that facilitates the work of the surgeon. This novel orogastric catheter is characterized in that this distal part carries a balloon (25) which, in the inflated state, has a shape substantially matching that of the pyloric antrum (4), in such a way as to be able to be lodged in this pyloric antrum (4), the end of the inflated balloon (25) then being in abutment against the pylorus (5), and the distal end of the body of the catheter (20) for its part being in abutment against the pyloric antrum (4), while the part of the body (21) of the catheter (20) arranged above the inflated balloon (25) is wedged against the wall of the lesser curvature (6) of the stomach (1), thus making it possible to determine the position of the start of the closure resection line in the area of the pyloric antrum (4), to define the closure resection line, and to calibrate the pyloric antrum (4) and the gastric sleeve to be preserved.
