*3.1.3 Primary obesity surgery endoluminal (POSE)*

The POSE procedure is an approach in which a reduction of the gastric fundus is created, using a peroral incisionless operating platform (USGI Medical. San Clemente, CA, USA) [26]. During this procedure, transmural plications are placed at eight to nine locations in the gastric fundus with an additional three plications in de distal part of the stomach. The notion behind this is to mechanically and physically restrict the surface to which ingested food comes in contact with the stomach. Moreover, it is assumed that the plications in the gastric fundus limit the capacity to accommodate food, and therefore, activation of gastric stretch receptors in response to food is more rapidly induced.

#### **Figure 4.**

*The g-Prox EZ® Endoscopic Grasper (A), transmural plications at the gastric fundus and distal part of the stomach (B), and stomach after POSE procedure (C) (from USGI Medical®, with permission).*

#### *3.1.3.1 Technique*

In order to create full-thickness serosa-to-serosa plications, a special overtubestyle platform, the Transport Endoscopic Access Device (USGI medical) is used at the operative site [26]. It has four working channels through which an endoscope and three additional instruments can be introduced. The g-Prox EZ® Endoscopic Grasper, a flexible shaft with a gripper at the tip to mobilize and capture target tissue (**Figure 4A**); the g-Lix™ Tissue Grasper, a flexible probe which is designed to assist the g-Prox in capturing the desired tissue; and the g-Cath EZ™ Suture Anchor Delivery Catheter which is equipped with a needle at its distal tip, and facilitates the creating of plications by penetrating the mobilized tissue with a pair of pre-loaded suture anchors. This ensures anchoring of the fold until there is serosal fusion.
