Peroral endoscopic myotomy using a novel thin therapeutic scope

Peroral endoscopic myotomy (POEM) has been gaining in popularity as an effective minimally invasive treatment for achalasia [1]. However, submucosal fibrosis and thicker esophageal mucosa in patients with achalasia can complicate scope insertion into the submucosa. Furthermore, passing the scope through the esophago-gastric junction can be challenging when the lower esophageal sphincter (LES) is tight. A thinner therapeutic scope may be desirable for such challenging POEM-based procedures. POEM with a nasoendoscope is a potential solution for such situations and has shown short-term outcomes comparable to those of conventional POEM [2]. However, only certain types of endoknives can be passed through the smaller working channels of nasoendoscopes, and a lack of scope stiffness may make their manipulation difficult. A novel thin therapeutic endoscope (EG-840TP; Fujifilm Co., Tokyo, Japan), with a diameter of 7.9 mm, a wide (3.2-mm) working channel, a wide-ranging downward angle of 160°, and enhanced stiffness compared to a nasoendoscope may overcome these challenges ([Fig. 1]).

Fig. 1 The EG-840TP – with a diameter of 7.9 mm, a working channel of 3.2 mm, a downward angle of 160°, and enhanced stiffness compared to nasoendoscopes – is well-suited for peroral endoscopic myotomy procedures.

A 28-year-old woman with achalasia (Chicago Classification type 1, Grade II dilation) was referred to our hospital, where we performed POEM using a EG-840TP scope ([Video 1]).

Peroral endoscopic myotomy (POEM) using a novel thin endoscope (EG-840TP).Video 1

An approach perpendicular to the esophageal wall is typically preferred for easy insertion into the submucosa during POEM. Unlike conventional therapeutic endoscopes with narrow-ranging downward angles, the EG-840TP facilitated scope insertion without the need for additional dissection of the entry site ([Fig. 2]). Its thinner tip resulted in a smaller entry and streamlined closure using clips ([Fig. 3]). Although creating a submucosal tunnel was challenging, owing to the limited workspace available as the patient had a tight LES, the smaller EG-840TP allowed us to create a sufficient tunnel ([Fig. 4]).

Fig. 2 a Conventional endoscopes with 120° downward angles lack sufficient force transmission in the narrow esophagus, making vertical approaches challenging. b The EG-840TPʼs large downward angle facilitates easy scope insertion into the submucosa using a downward angle.

Fig. 3 a Closure with clips is performed using a conventional endoscope. The prolonged incision requires a significant number of clips. b Closure with clips is performed using the EG-840TP. The slim endoscope diameter results in a shorter entry incision length, facilitating easy closure with fewer clips.

Fig. 4 a Submucosal tunneling near the lower esophageal sphincter (LES) is performed using a conventional endoscope. b Submucosal tunneling near the LES is performed using an EG-840TP. The novel scope makes it easier to secure the workspace, simplifying the creation of the submucosal tunnel.

This novel endoscope, with its potential advantages in challenging circumstances, may represent a new standard therapeutic endoscope for POEM procedures.

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• References

• 1 Mundre P, Black CJ, Mohammed N. et al. Efficacy of surgical or endoscopic treatment of idiopathic achalasia: a systematic review and network meta-analysis. Lancet Gastroenterol Hepatol 2021; 6: 30-38
• 2 Hernandez Mondragón OV, González Martínez MA, Solórzano Pineda OM. et al. Feasibility of the peroral endoscopic myotomy (POEM) procedure with a new small-caliber endoscope (thin-POEM) in patients with achalasia. Endoscopy 2019; 51: 350-354