Usefulness of tunnel dissection for upper gastrointestinal submucosal tumors

We read with interest the articles by Inoue et al. [1] and Gong et al. [2] regarding endoscopic submucosal tunnel dissection for treatment of upper gastrointestinal submucosal tumors (SMTs). SMTs of esophagus and cardia were resected by tunnel dissection with excellent results in these studies. We would like to express our opinion after carefully analyzing these reports.

The tunnel method may be a fine choice for the management of upper SMTs. As suggested by Inoue and colleagues, it could be an option for resecting esophageal and cardia SMTs smaller than 4 cm. However, in our view, depending on the characteristics of lesions, it is difficult to confirm that the tunnel method is always superior to other methods. In clinical situations, it is difficult to treat SMTs smaller than 5 cm under the upper esophageal sphincter because the tunnel method entails an incision in the upper 5 cm of an SMT. Also, performance of the tunnel method would be difficult if there was fibrosis in the lower esophagus due to severe reflux esophagitis or for SMTs located under a large diverticulum.

Inoue et al. stated that lesions originating from or infiltrating into the proper muscle layer are unlikely to be completely and safely dissected with ESD, and tumors larger than 4 cm can hinder endoscopic visualization because of the effect of the tumor mass in a limited submucosal space. However, we have previously reported the endoscopic removal of esophageal SMTs without general anesthesia. In our study, we found that the resection method could be difficult technically, but endoscopic removal of esophageal SMTs up to 7.5 cm in size was shown to be safe and effective [3] [4].

The article by Gong et al. reported an en bloc tumor resection rate of 83.3 % for tumors measuring an average of 19.6 mm. However, the indications for upper gastrointestinal SMT resection were not discussed in this study. Resection of the mass should be considered in symptomatic patients, for those in whom diagnosis is uncertain, and for those in whom the lesion shows interval growth during surveillance endoscopy [5]. However, Gong et al. did not indicate whether patients were symptomatic or whether there was tumor growth. In their article, they reported that two patients had complications such as pneumothorax and subcutaneous emphysema. In order to successfully carry out the tunnel method, sufficient practice and considerable time are required. If this new method can only be used by experts and has a high complication rate, it will not be widely used. In addition, general anesthesia and complex preparations are needed for performance of tunnel dissection. Previous reports have shown that laparascopic or thoracoscopic surgery produced excellent results with almost no complications for the treatment of SMTs in the esophageal or esophagogastric junction. Therefore, this type of surgery is considered to be an appropriate method for the resection of SMTs [6] [7]. In our experience with resection of upper gastrointestinal SMTs, the potential benefit of tunnel dissection is marginal compared with other removal methods.

The pioneering clinical experiences of endoscopic tunnel dissection are attractive. However, an in-depth discussion of this new technique is needed regarding the advantages and disadvantages compared with the previous SMT removal technique. Also the usefulness of such an innovative endoscopic procedure should be further discussed. For the resection of SMTs, the methods should be carefully chosen, taking into consideration patient status, endoscopist skill, etc. Through further studies and discussions, we look forward to finding better methods for successfully resecting upper gastrointestinal SMTs.

• References

• 1 Inoue H, Ikeda H, Hosoya T et al. Submucosal endoscopic tumor resection for subepithelial tumors in the esophagus and cardia. Endoscopy 2012; 44: 225-230
• 2 Gong W, Xiong Y, Zhi F et al. Preliminary experience of endoscopic submucosal tunnel dissection for upper gastrointestinal submucosal tumors. Endoscopy 2012; 44: 231-235
• 3 Hyun JH, Jeen YT, Chun HJ et al. Endoscopic resection of submucosal tumor of the esophagus: results in 62 patients. Endoscopy 1997; 29: 165-170
• 4 Chun HJ, Hyun JH. Endoscopic removal of submucous tumours. Baillieres Best Pract Res Clin Gastroenterol 1999; 13: 145-163
• 5 Das A. Tumors of the esophagus. In: Feldman M, Friedman LS, Brandt LJ, , eds. Sleisenger and Fordtran’s gastrointestinal and liver disease. 9th edn. Philadelphia: Saunders Elsevier; 2010: 768-769
• 6 von Rahden BH, Stein HJ, Feussner H et al. Enucleation of submucosal tumors of the esophagus: minimally invasive versus open approach. Surg Endosc 2004; 18: 924-930
• 7 Hwang SH, Park DJ, Kim YH et al. Laparoscopic surgery for submucosal tumors located at the esophagogastric junction and the prepylorus. Surg Endosc 2009; 23: 1980-1987