Gastric peroral endoscopic myotomy, or GPOME, is emerging as a treatment option for patients with gastroparesis. A novel multimodal cutting-cartering device has been reported for ESD and EPOME. This device has not been reported with GPOME, where the unique shape and design may enhance submucosal dissection in the uphill direction towards the pilaris. We utilized this device, along with the navigational tunnel technique, in three GPOME patients. Three patients underwent GPOME for the treatment of symptomatic gastroparesis confirmed by prolonged gastric emptying studies. Mucosal cornering markings were made to outline the tunnel, starting 3 to 4 cm proximal to the pilaris. The tunnel was created by submucosal injection of carboxymethylcellulose with methylene blue, starting right at the pilaris and then extending backwards to the incision point. Submucosal dissection was performed by following the prior submucosal injection straight to the pilaris. Clinical Implications The bipolar blade uses much lower energy than conventional monopolar knives, which should decrease depth of injury and tissue damage. In addition, the unique probe design with its protective bottom hull may enhance safe and efficient submucosal dissection by minimizing injury to both deep and superficial tissue layers. The navigational tunnel technique provides a visual path for the submucosal dissection straight to the pilaris. These combined attributes may improve the efficiency of the submucosal tunnel dissection, which is usually the most time-consuming portion of the procedure. This case is a 43-year-old male with a past medical history of GERD, status post multiple antireflux surgeries complicated by symptomatic gastroparesis for the past 3 years. His gastrointestinal cardinal symptom index GCSI was 35 out of 45. The gastric emptying study showed 52% retained food at 4 hours. His symptoms remained refractory despite multiple medications. He is non-diabetic. Abdominal imaging with CT and ultrasound showed post-operative changes otherwise unremarkable. On EGD, the pilaris was felt to be tight. First, microwave markings were used to delineate the length and the width of the submucosal tunnel. The length was approximately 3 cm and the width approximately 1.5 cm. Starting at the pilaris, a submucosal injection at the distal end of the tunnel is performed using a 25-gauge needle. With subsequent contiguous injections proximally towards the incision line. The navigational tunnel pre-injection for all three cases are shown here. The tip of the blade is used to start the mucosal incision. The incision is fully extended to the right and to the left. The top of the entrance is further expanded. The tunnel is extended towards the pilaris in an uphill direction. The protective hull at the bottom of the blade minimizes inadvertent deep muscle injury. The conical hood facilitates entrance into the tunnel. The bipolar blade cuts both in the forward and lateral directions. Submucosal vessels are prophylactically cauterized using the white microwave portion of the blade. The dissection continues just above the muscle layer. At the end of the tunnel, the pilaris is identified by the smooth crescent moon shape of the transverse muscle bundle and by the presence of vertical palisading vessels shown by the red arrows. As shown by the dotted red line, our goal is to cut the pilaris without cutting the circular muscle of the duodenum and then extending the incision approximately towards the pre-pilaris. The total length of the myotomy is approximately 1.5 cm. After starting the pilaral myotomy, a thin right angle tip knife is used in order to precisely cut all three muscle layers while minimizing exposing the peritoneum by leaving the serosal layer intact as much as possible. A second or double myotomy extends the opening of the sphincter. After the myotomy is completed, the tunnel is inspected for vessels that may need prophylactic cautery as well as to look for serosal defects. Then the outside of the tunnel is also inspected which shows no mucosal defects and a loose pilaris. Closure is achieved by endoscopic suturing. The approximate time for marking was 3 minutes, for navigational tunnel pre-injection, 5 minutes, for mucosal incision, 3 minutes, submucosal tunnel, 9 minutes and pilaral myotomy, 7 minutes. In conclusion, in GPOME, this novel multimodal bipolar device can be utilized for mucosal incision and submucosal tunneling without the need for coag graspers. The navigational tunneling technique helps guide the submucosal dissection towards the targeted pilaris and minimizes the need for additional intra-procedural injections. The bipolar blade for cutting combined with microwave for coagulation minimizes undesired tissue damage and may enhance safety and the unique protective hull of the device appears well suited for GPOME where the tunnel is extended in an uphill direction.

gastric peroral endoscopic myotomy

GPOEM

gastroparesis

multimodal cutting-cartering device

navigational tunnel technique