Endoscopic mucosal resection using a cap-fitted endoscope improves tissue resection and pathology interpretation: an animal study

Abstract

Background: Endoscopic mucosal resection using a cap-fitted endoscope (EMRC) has been proposed to be significantly better and safer for tissue resection compared with standard snare EMR. However, there are no valid animal or clinical data to support this. We aimed to compare EMRC with standard snare EMR in a porcine model with respect to tissue resected, ease of procedure, and degree of diathermic injury to the resected specimen.

Methods: Gastric EMRs were randomly performed in pigs using a variety of techniques, including EMRC (1mm and 17-mm cap) and the standard snare technique, using a single-channel method without a grasping forceps. Geometric and histological assessment of the resection specimen for size, histological depth, and diathermic injury were performed by a single pathologist, blinded to the endoscopic techniques used.

Results: Thirty-six gastric mucosal resections were randomly performed in three pigs. Use of EMRC resulted in a statistically significant greater resection specimen by weight, size, and histological depth compared with standard EMR (P < 0.04). Large-cap EMRC resulted in a statistically significant greater resection weight and size compared to small-cap EMRC (P < 0.05). There was a statistically significant greater degree of diathermic injury in the specimens resected using the standard snare EMR technique compared with EMRC (P < 0.006). There were no acute complications with either technique.

Conclusion: Gastric EMRC is more technically effective than and as safe and easy as standard snare EMR. Use of the cap, especially the larger cap, is associated with larger and deeper mucosal resection and less diathermic injury compared with the standard snare technique, making the pathologic assessment of depth and margin involvement more reliable. When possible, EMRC should be the EMR method of choice.