Optimization of insufflation and pressure control in third-space endoscopy

Third-space endoscopy requires a delicate and accurate insufflation technique to secure the endoscopic visualization and maintain the working space. However, optimal third-space insufflation parameters have yet to be determined. The aim of this study was to assess: (1) the diversity of endoluminal third-space pressure by manual insufflation, and (2) the performance of the insufflation settings for third-space endoscopy.

A submucosal tunnel was created in the upper posterior wall of the porcine stomach. Using two-channel esophagogastroduodenoscopy, one channel was used for insufflation and the other was used for pressure measurement. Experiment 1 Endoluminal submucosal tunnel pressure was measured in a 10-cm submucosal tunnel of a single porcine. Six board-certified endoscopists in turn maintained what they considered sufficient exposure under manual insufflation. Experiment 2 Endoluminal submucosal tunnel pressure and number of insufflations were measured using the pressure-regulated insufflation device; the differences in the submucosal tunnel length (long: 10-cm, short: 4-cm) and the insufflation route diameter (large: 3.8-mm, small: 2.2-mm) were compared.

Experiment 1 The endoluminal submucosal tunnel pressure profiles during third-space endoscopy varied between endoscopists. Experiment 2 Longer submucosal tunnels and larger insufflation route diameters lead to stable endoluminal submucosal tunnel pressure. The gap with the preset pressure of the insufflator and endoluminal pressure narrowed, and the required number of insufflations decreased with longer tunnel length and larger route diameter.

The pressure dynamics in third-space endoscopy differed among endoscopists. Longer submucosal tunnels and larger insufflation route diameters lead to stable endoluminal submucosal tunnel pressure.