EMR

Endoscopic mucosal resection (EMR) has become a well established treatment modality for removal of early stage neoplastic lesions in the gastrointestinal (GI) tract. A variety of EMR techniques have been described utilizing various solutions for submucosal injection and mucosal elevation, as well as a variety of devices and techniques for removal of a lesion.

The EEMR (endoscopic esophageal mucosal resection tube) method reviewed by Makuuchi and coworkers [1] uses a specially manufactured overtube that is currently not widely available outside of Japan. This technique involves maneuvers of overtube, endoscope, snare and/or biopsy forceps relative to each other that may not always be intuitive. Like any EMR technique, this method requires considerable expertise underscoring the fact that endoscopic mucosal resection should only be undertaken by endoscopists with considerable experience in these and other interventional techniques (and willingness to deal with complications if they arise).

Arguably one of the most important factors when considering any EMR technique is the availability of high quality endoscopic ultrasound (EUS) for local staging of early neoplastic lesions. As emphasized by the authors, accurate tumor staging is critical to determine the resectability and curability of such lesions. EUS is highly operator dependent and high frequency ultrasound probes which are not available at all centers are commonly needed for the detailed assessment of small lesions. Care should be taken to refer patients to an expert endosonographer to maximize the accuracy of subsequent patient triage to endoscopic, medical or surgical therapy.

Whether tumors that extend beyond the mucosal layer (i. e. those involving the submucosa) should be selected for EMR is a contentious issue. As discussed in the current manuscript, lymph node metastases will be present in as many as 15 % of these patients and one might argue that predicated on the patient’s age, overall clinical status and operative risk, he or she may be better served with conventional surgical intervention. While the morbidity of surgery remains significant, the operative mortality is very low in experienced hands. One of us (R.A.K.) works at an institution that has achieved a 0 % mortality in 174 esophagectomies performed over the last 6 years.

It should be emphasized that EMR techniques have not been compared to surgical resection in controlled clinical trials. In the absence of such trials and with still relatively limited experience using the various EMR techniques, it is difficult to proclaim ”absolute indications” for EMR as suggested by Makuuchi and colleagues. Our own approach involves the evaluation of any potential EMR candidate by a multidisciplinary team which includes an experienced esophageal surgeon, in order to fully inform the patient about the entire spectrum of available treatments and their individual advantages and potential risks. The decision whether to proceed with endoscopic resection is then made after careful review of all patient and disease related factors in accordance with patient preferences.

As interventional endoscopists, we, like Makuuchi and colleagues, are excited about the rapid development of these minimally invasive techniques as they represent a significant expansion of our therapeutic armamentarium and are, no doubt, of great benefit if used judiciously by experienced operators in well selected patients.

References

• 1 Makuuchi H, Ell C, Yoshida T. Mucosectomy for Early Esophageal Cancer.  Endoscopy. 2004;  36 1013-1018