Abstract
We read with interest “How I teach it: POEM” by Marks et al in this issue of Foregut. 1 The approach outlined reflects how a substantial number of successful therapeutic endoscopists and surgeons who currently perform per-oral endoscopic myotomy (POEM) were originally trained. 2 These methods are time-tested and lead to excellent results. The authors emphasize that the technical details of performing POEM vary across institutions and between providers, and there is a lack of literature evaluating whether these differences impact outcomes. Nonetheless, we thought it would be helpful to mention some modifications to the technique that have become more mainstream in recent years and to highlight key differences in the approach to training among gastroenterology compared to surgery.
In our experience, most endoscopists perform POEM with the same person controlling both the insertion tube of the endoscope as well as the dials. Graduated autonomy is then provided to the trainee by having them perform simple steps of the procedure first (eg, extending submucosal tunnel after a stable scope position is established and before reaching the gastroesophageal junction area) and slowly and systematically advance to more difficult steps such as the myotomy. It would be unusual for a gastroenterology trainee to work the dials without also having control over the endoscope shaft.
The practice of positioning the endoscopist (specifically the learner) at the head of the table has been slowly replaced by the natural gastroscopy position where the person holding the scope is always to the left of the patient. This should not impact the trajectory when tunneling in the esophagus. Similarly, many endoscopists might choose to forego the use of an overtube during POEM to simplify the technique.
With regards to equipment, the triangle tip knife is certainly used frequently as described by the authors, but most available endoscopic electrosurgical knives can be successfully used for POEM. More recently, a common practice is to use a hybrid knife that affords both injection and dissection with the same instrument, as this can save time and reduce the risk of tissue injury when exchanging instruments. Ideally, trainees should become comfortable with both posterior and anterior approaches for performing POEM as patients may have prior interventions that limit one of these approaches. Finally, trainees may find retrograde myotomy easier to learn in the beginning with more control and smaller risk of mucosal injury but can eventually adapt to an antegrade myotomy.