Intra-intestinal catheter implantation

For this procedure, mice were at least 8 weeks of age. Mice anesthetized with isoflurane, pre-surgical care, and aseptic preparation was taken. An abdominal midline incision through the skin and muscle was performed, extending from the xyphoid process about 1.5 cm caudally. A second 1-cm incision was made between the scapulae for catheter externalization. The skin was separated from the subcutaneous tissue to form a subcutaneous tunnel between the neck and abdomen incisions to facilitate catheter placement. A small puncture hole was made on the left side of the abdominal wall to insert the catheter (C30PU-RGA1439). The stomach was externalized, and a purse-string stitch was made at the edge of the fundus and corpus on the side of the greater curvature of the stomach using 7-0 non-absorbable Ethilon suture (1647G). Then, a puncture was made at the center of the purse-string stitch to insert and advanced the catheter 2.5 cm distal to the pyloric sphincter (intraduodenal catheter).

While for the intracecal catheter, a puncture was made on the larger curvature of the cecum to insert and advance the catheter 1 cm, at the edge of the colon and cecal junction. The cecal catheter was secured to the tissue with sterile surgical drape (J0258). The catheter was secured by the purse-string suture at the catheter collar. The abdominal cavity was irrigated with sterile saline and the abdominal wall was closed. The other end of the catheter was attached to a vascular button (VABM1B/22), sutured to the muscle layer at the interscapular site and the incision was closed. The vascular button was closed with a protective aluminum cap (VABM1C) to prevent catheter obstruction. Mice were provided with subcutaneous flunixin and moistened chow for 2 days after surgery. Mice were allowed to recover for 7-10 days prior to behavioral experiments.