C. Alexander Mosse

Endoscopic full-thickness resection with sutured closure in a porcine model

BACKGROUND Some early gastric cancers might be advantageously staged and treated by full-thickness resection if secure methods for closing the defect were available. The aim of this study was to test the feasibility of full-thickness gastric resection. METHODS Full-thickness gastric resections were performed by using a ligating device without submucosal injection in survival studies in pigs (n = 8). The defects were closed by using new methods for suturing, locking, and cutting thread through a 2.8-mm accessory channel. Stitches (n = 2-4) were placed close to the target area before resection. OBSERVATIONS Full-thickness resections (n = 8) were performed. The pigs survived without incident for 21 to 28 days. Healing of the suture site was evident at follow-up endoscopy. Suture sites were water tight. The pull-out force with stitches by using this new sewing method was significantly higher than with endoscopic clips (20.3 N +/- 0.94 vs. 2.2 N +/- 0.42, p < 0.05). CONCLUSIONS Endoscopic full-thickness resection with sutured defect closure was feasible and appeared safe in these survival experiments.

Transgastric gastropexy and hiatal hernia repair for GERD under EUS control: a porcine model

BACKGROUND Endoluminal operations for gastroesophageal reflux currently are limited by the inability to visualize and manipulate structures outside the wall of the gut. This may be possible by using EUS. The aims of this study were the following: to define the EUS anatomy of structures outside the gut that influence reflux, to place stitches in the median arcuate ligament, to perform posterior gastropexy, and to test the feasibility of crural repair under EUS control in pigs. METHODS In survival experiments in 22 pigs, by using a linear-array echoendoscope, the median arcuate ligament and part of the right crus were identified and punctured with a needle, which served as a carrier for a tag and thread. These were anchored into the muscle. An endoscopic sewing device was used, allowing stitches to be placed through a 2.8-mm accessory channel to any predetermined depth. New methods allowed knot tying and thread cutting through the 2.8-mm channel of the echoendoscope. RESULTS Stitches were placed through the gastric wall into the median arcuate ligament, and one stitch was placed just beyond the wall of the lower esophageal sphincter. The stitches were tied together and locked against the gastric wall. Median lower esophageal sphincter pressure, determined manometrically, was 11 mm Hg before surgery and 21 mm Hg after stitch placement (p=0.0002). The length of the lower esophageal sphincter increased from a median of 2.8 cm before the procedure to 3.5 cm after the procedure. At the postmortem, the median force required to pull the tags out of the median arcuate ligament was 2.8 kg. CONCLUSIONS This study demonstrates that transgastric gastroesophageal reflux surgery, by using stitching under EUS control, can significantly increase lower esophageal sphincter pressure in pigs.