When reconstructing the portal vein (PV) following hepatopancreatoduodenectomy (HPD) with PV resection, a new porto-systemic bypass (PSB) technique can be employed to prevent intestinal vascular congestion. The Whipple procedure is performed in a standard manner, as long a portion of the gastrocolic trunk is preserved for insertion of an antithrombogenic catheter (ATC). After harvesting the left external iliac vein and exposing the right great saphenous vein, the end of the ATC is inserted in the superior mesenteric vein via the gastrocolic trunk in the distal direction and the other end of the ATC is inserted in the greater saphenous vein. PSB is achieved as a result of the venous pressure gradient. By employing this technique, an ATC can be inserted without damaging another mesenteric venous branch and with minimal damage to the endothelium, and the small intestine is not exposed in the operative field until enteric reconstruction is started. This technique is a promising option for PSB during HPD with PV resection.