Myotomy for esophageal achalasia – laparoscopic versus peroral endoscopic approach

In their study published in this issue of Endoscopy, Inoue et al. present an interesting novel method for endoscopic treatment of achalasia [1]. It is the first report in the literature on this specific technique in humans, although the feasibility of the submucosal endoscopic approach and its possible impact on current treatment strategies for achalasia have been previously discussed in an animal study [2].

The technical details of this new approach reflect the surgical experience of the authors: it involves dissection and division of the inner circular muscle layer of the esophagus through a submucosal tunnel created endoscopically by a small proximal opening of the esophageal mucosa.

Patients underwent a comprehensive preoperative work-up including barium swallow, computed tomography (CT) scan, and esophageal manometry. However, to establish a diagnosis of achalasia, only the resting pressure of the lower esophageal sphincter (LES) was measured. Swallow-related relaxation of the LES and loss of peristalsis within the tubular esophagus as the manometric hallmarks of achalasia were not taken into account, leaving some doubt about the reliability of preoperative diagnosis.

Dissection of the circular muscle fibres alone led to a significant reduction of LES pressure as demonstrated by postoperative manometry. However, the standard surgical technique involves complete division of both circular and longitudinal muscle layers. In our experience and that of others, completeness of myotomy is a prerequisite for sufficient and long-term reduction of LES pressure and is the basis for the excellent results of the transperitoneal approach documented in a recent meta-analysis [3].

A potential advantage of the POEM technique might be the option to perform a very long myotomy of the thoracic esophagus. During laparoscopy, high mediastinal dissection is sometimes difficult to achieve, particularly in patients with megaesophagus and periesophageal fibrosis. Also, the possibility of vagal nerve injury, with the risk of postoperative gastric emptying problems, is certainly substantially reduced by this new technique.

However, a major disadvantage of POEM compared with traditional endoscopic interventional procedures such as Botox injection or pneumatic sphincter dilation is the fact that very sophisticated technical equipment, general anesthesia, and thorough postoperative surveillance are mandatory for the performance of safe endoscopic myotomy. Therefore, POEM cannot reasonably be recommended as an outpatient procedure. The complexity of the required infrastructure is similar to that needed for transperitoneal Heller’s myotomy. Moreover, the mean duration of POEM was more than 2 hours, which is similar to that of surgical myotomy and notably longer than that of any other nonsurgical endoscopic procedure. Therefore, we feel that the potential benefit in terms of decreased invasiveness might be marginal compared with laparoscopic surgery.

The authors present short-term results with a mean follow-up of only 5 months. In our experience, real therapeutic success in achalasia can only be judged on a long-term basis. Therefore, it seems very important that Dr. Inoue and colleagues closely follow this group of patients.

For the visceral surgeon, there are two major causes of concern about this new technique:

First, endoluminal myotomy appears to be an extremely sophisticated and demanding technique even for experienced endoscopists. The learning curve will be very gradual – in a very rare disease. There is no doubt that if this technique gains popularity, serious complications may occur, and we all know the terrible consequences of purulent mediastinitis [4]. Revisional surgery might be difficult and involve extensive procedures such as esophagectomy.

Second, surgical revision in patients with unsatisfactory functional results after POEM might be a problem because the plane between the submucosal and muscular layers will be inflamed and scarred after the endoluminal approach. Meticulous dissection of this layer will be extremely difficult. It is well documented that myotomy after failed endoluminal procedures such as Botox injection or esophageal dilation carries a higher risk for intraoperative perforation and a worse functional outcome than primary Heller’s myotomy [5] [6].

Since Georg Gottstein from Breslau conceived the idea of myotomy in 1901 [7] and Ernst Heller from Leipzig performed the first procedure in 1913 [8], numerous attempts have been made to replace the initial procedure. All of them have failed. In a recent meta-analysis on 3086 patients, laparoscopic myotomy was confirmed as the gold standard for therapy of achalasia with a functional success rate of nearly 90 % and an overall mortality of 0.1 % [3]. Considering these excellent results, the quest for the holy grail of achalasia treatment will be a difficult exercise! Improving on the results shown in this recent meta-analysis is an exacting task. On the other hand, we fear that broad application of endoluminal submucosal myotomy would probably result in more rather than fewer recurrences and complex surgical interventions. The transluminal method is not always better than the extraluminal approach.

This is our current surgical view on achalasia treatment, based on our personal experience and confirmed again by the recent meta-analysis [3]. However, we are open to technical improvements and continuing interdisciplinary discussion of therapeutic strategies. The authors must be congratulated for a very sophisticated endoscopic technique and their courage to begin such a series. The preliminary results are promising and we are very curious about the long-term results. A thorough follow-up of these patients will be the responsibility of Dr. Inoue and his co-workers.

Competing interests: None

References

• 1 Inoue H, Minami H, Kobayashi Y. et al . Peroral endoscopic myotomy (POEM) for esophageal achalasia.  Endoscopy. 2010;  42 265-271
• 2 Pasricha P J, Hawari R, Ahmed I. et al . Submucosal endoscopic esophageal myotomy: a novel experimental approach for the treatment of achalasia.  Endoscopy. 2007;  39 761-764
• 3 Campos G M, Vittinghoff E, Rabl C. et al . Endoscopic and surgical treatments for achalasia. A systematic review and meta-analysis.  Ann Surg. 2009;  249 45-57
• 4 Vallböhmer D, Hölscher A H, Hölscher M. et al . Options in the management of esophageal perforation: analysis over a 12-year period.  Dis Esophagus 2009 Oct. 26;  [Epub ahead of print]
• 5 Smith C D, Stival A, Howell D L. Endoscopic therapy for achalasia before Heller myotomy results in worse outcomes than Heller myotomy alone.  Ann Surg. 2006;  243 579-584
• 6 Portale G, Costantini M, Rizzetto C. et al . Long-term outcome of laparoscopic Heller-Dor surgery for esophageal achalasia: possible detrimental role of previous endoscopic treatment.  J Gastrointest Surg. 2005;  9 1332-1339
• 7 Gottstein G. Über Pathologie und Therapie des Cardiospasmus.  All Med Centr Z. 1908;  77 563
• 8 Heller E. Extramuköse Kardiaplastik beim chronischen Kardiospasmus mit Dilatation des Ösophagus.  Mitt Grenzgeb med Chir. 1914;  27 141