Special articlePer-oral endoscopic myotomy, 1000 cases later: pearls, pitfalls, and practical considerations
Section snippets
Accessories and electrosurgical settings
Various endoscopic accessories are used during POEM, and the choice of endoscopic knife and distal attachment typically depends on the endoscopist’s expertise and preference. At our center, the ST Hood Short-type (Fujifilm, Tokyo, Japan), which has been shown to decrease procedure time by quicker entry into the submucosal space, is the distal attachment of choice. The Triangle tip knife (Olympus Medical Systems, Tokyo, Japan) is the preferred needle-knife.2 Recently, the water-jet–assisted
Patient position
Currently, no evidence supports placing the patient in either the left lateral or supine position for the POEM procedure. From our experience, placing the patient in the supine position is preferred because as the esophagus becomes severely dilated in achalasia, the proximal segment initially deviates to the right and subsequently deviates back to the midline at the gastroesophageal junction (GEJ). In advanced sigmoid achalasia (sigmoid type 2), there are many acute angulations before reaching
Landmarks
Before the first cut, luminal landmarks should be identified: upper esophageal sphincter, spine, trachea, left main bronchus, aortic arch, and lower esophageal sphincter (LES) (Fig. 1). These landmarks help to orient the operator to the esophageal walls relative to the GEJ, stomach, mediastinal and peritoneal structures; serve as a guide along the appropriate path; and provide cues to the adjacent mediastinal/peritoneal structures.1
Injection and mucosal incision
Approximately 10 mL of solution is used for the initial submucosal injection to produce a large cushion, thereby promoting a safe mucosal incision. After submucosal injection, the operator should reorient him- or herself before making an incision by repeated advancement, withdrawal, and reidentification of the landmarks to ensure the incision is performed in the desired location. If the operator is not cognizant of the potential for luminal distortion and disorientation after submucosal
Esophageal
Attentiveness to the orientation of the circular muscle bundles is critical. The orientation of the muscle bundles must be maintained perpendicular to the endoscope to avoid deviation from the intended site of the esophageal and GEJ myotomy. By maintaining the perpendicular orientation of the muscle bundles and symmetric lateral margins, the operator can be confident that the tunnel is progressing in the intended direction (Fig. 3). If one side starts to “lag” behind the other, the submucosal
Esophageal myotomy
The techniques used to perform a selective myotomy vary depending on the position of the mucosal incision and endoscopic orientation. When the muscle layer is at the 12 o’clock and the mucosa at the 6 o’clock position (generally for anterior myotomy), acute tip angulation is required to hook the circular muscle layer. In contrast, when the muscle is kept at the 6 o’clock position (generally for posterior myotomy, which is our current practice), much less tip angulation is required and there is
Closure
The importance of precise symmetric clip deployment, particularly of the first clip, should be emphasized because it is a crucial step for a safe and successful POEM procedure. The first clip should be placed just at or slightly beyond the distal margin of the mucosal incision with the 2 prongs grasping an equal amount of tissue on either side of the defect, creating a symmetric fold (Fig. 7). With subsequent clips the transparent hood is placed under the preceding clip and gently lifted,
Suction
With a distal attachment, the effect of suction on mucosa and submucosa is intensified. Care should be taken to avoid vigorously suctioning the submucosa or mucosa. This point often needs to be emphasized to trainees learning POEM because previous experience with typical luminal endoscopy would have been forgiving to liberal suctioning because it is less delicate than submucosal endoscopy. Excessive suctioning can result in bleeding by shearing of the submucosal vessels or cause hematomas and
Bleeding
In the submucosal tunnel, maneuverability and space are limited, and brisk bleeding can easily obscure the working space. Maintaining a clear working space is critical because the accumulation of blood and heme staining of the submucosal fibers will lead to charring and poor visibility, predisposing to further vessel dissection, bleeding, and mucosal injury after application of electrosurgical current. During bleeding in the tunnel, pulsed irrigation, gentle suction, and tamponading of the
Advanced sigmoid achalasia
With advanced sigmoid achalasia, the esophagus can be tortuous, both distally and proximally. Because of the severe dilation, the spine and trachea indentations on the esophagus are also exaggerated, which can make maneuvering the endoscope more difficult, particularly in the proximal esophagus. In advanced disease, the thoracic esophagus tends to deviate to the right, only to shift back over to the midline at the GEJ. This phenomenon should be taken into account because it can render luminal
LES in other spastic motility disorders
In jackhammer esophagus and diffuse esophageal spasm, currently no evidence addresses whether the LES should be preserved or cut if it is not involved in the abnormal motility. Our view is that the LES should be included in the myotomy. The progression of diffuse esophageal spasm and hypercontractile esophagus to achalasia has been previously reported.8, 9 If the LES is not included in the myotomy and there is subsequent progression to achalasia, the patient will develop symptoms and require
Learning curve
The learning curve for endoscopic procedures and, in particular, new procedures such as POEM, is an area of debate. For typical procedures such as colonoscopy, older recommendations have stated that 100 procedures were required to achieve competence.12 However, further comprehensive analysis that included defined performance metrics and validated competency thresholds deemed that an average of 275 procedures were required to achieve competence. In recent years there has been a paradigm shift
Conclusion
Since the introduction of POEM as an investigational procedure, it has thrived and gained acceptance throughout the world as a treatment for achalasia and other spastic esophageal motility disorders. We hope the dissemination of the information gained from our experience and reflection serves as a foundation and catalyst to further refine and advance POEM and stimulate international discourse and collaboration.
References (15)
A novel endoscopic tapered-tip CAP significantly reduces time for endoscopic submucosal tunneling [abstract]
Gastrointest Endosc
(2014)- et al.
Formation of large esophageal diverticulum after peroral endoscopic myotomy
Gastrointest Endosc
(2015) ASGE's assessment of competency in endoscopy evaluation tools for colonoscopy and EGD
Gastrointest Endosc
(2014)Peroral endoscopic esophageal myotomy: defining the learning curve
Gastrointest Endosc
(2013)The light at the end of the tunnel: a single-operator learning curve analysis for per oral endoscopic myotomy
Gastrointest Endosc
(2015)- et al.
Peroral endoscopic myotomy: an evolving treatment for achalasia
Nat Rev Gastroenterol Hepatol
(2015) - Balassone V, Ikeda H, Kazuya S, et al. Peroral endoscopic myotomy: first human experience with a water-jet-assisted...
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DISCLOSURE: All authors disclosed no financial relationships relevant to this publication.