NOTES and the mediastinum

When natural orifice transluminal endoscopic surgery (NOTES) was introduced more than 10 years ago, it presented the possibility of less-invasive, initially abdominal procedures through the gut wall without skin incision. As procedures were carried out without sufficient basis of experience and knowledge about possible hazards, the most critical points and possible complications of NOTES procedures were defined early on in a white paper [1]. When interest was shown in applying NOTES through the esophagus into the mediastinum [2], it was thought to be an unreasonable and hazardous undertaking. Years earlier, in the mid-1990 s, introduction of mediastinal endoscopic ultrasound-fine-needle aspiration (EUS-FNA) caused similar disapproval amongst thoracic surgeons. However, the technique later proved to be a safe and minimally invasive technique that allows complete inspection of and tissue sampling in the entire mediastinum when used in combination with endobronchial ultrasound (EBUS). EUS-FNA has largely replaced standard video-assisted mediastinoscopy (VAM) for evaluation and tissue sampling of malignant and benign mediastinal nodes and lesions.

Evolving experience with NOTES over the last 10 years, since its role in the thoracic and medisastinal space was initially explored, facilitated further understanding of the potential hazards of endoscopic access to the mediastinum. The recent hype around per-oral endoscopic Heller myotomy (POEM), although not strictly NOTES, suggests that a transesophageal approach (to the non-luminal musculature of the esophagus and submucosal tumors through the new “third space”, the submucosal tunnel) may become one of the most useful settings for a NOTES-like procedure [3] [4].

One of the few groups with noteworthy experience with NOTES in the thoracic space has published a study in this issue [5]. In accord with the Noscar White paper, the authors concentrated on feasibility, access, potential hazards, and safety [1]. Most of the studies available to date were performed in an animal model and only a few in humans, if POEM procedures are excluded [6] [7]. This is mainly due to concerns about the safety of the currently available access and closure methods and devices and uncertainty about whether possible complications, including infection and bleeding, can be addressed adequately.

• References

• 1 ASGE/SAGES Working Group on NOTES White Paper. Gastrointest Endosc 2006; 63: 199-200
• 2 Fritscher-Ravens A, Mosse CA, Ikeda K et al. Endoscopic transgastric lymphadenectomy by using EUS for selection and guidance. Gastrointest Endosc 02/2006; 63: 302-306
• 3 Fritscher-Ravens A, Patel K, Ghanbari A et al. Natural orifice transluminal endoscopic surgery (NOTES) in the mediastinum: long-term survival animal experiments in transesophageal access, including minor surgical procedures. Endoscopy 10/2007; 39: 870-875
• 4 Makris KI, Rieder E, Swanstrom LL. Natural orifice trans-luminal endoscopic surgery (NOTES) in thoracic surgery. Semin Thorac Cardiovasc Surg 2010; 22: 302-309
• 5 Cordova H, Cubas G, Boada M et al. Adverse events of NOTES mediastinoscopy compared to conventional video-assisted mediastinoscopy: a randomized survival study in a porcine model. EIO
• 6 Hampe J, Schniewind B, Both M et al. Use of a NOTES closure device for full-thickness suturing of a postoperative anastomotic esophageal leakage. Endoscopy 2010; 42: 595-598
• 7 Hampe J, Schniewind B, Arlt A et al. Closure of anastomotic leakage and iatrogenic perforation with endoscopic suturing: An ongoing pilot study in patients: closure of anastomotic leakage and iatrogenic perforation with endoscopic suturing: An ongoing pilot study in patients. Gastrointestinal Endosopy 2010; 71: AB133
• 8 Fritscher-Ravens A, Hampe J et al. Clip closure versus endoscopic suturing versus thoracoscopic repair of an iatrogenic esophageal perforation: a randomized, comparative, long-term survival study in a porcine model. Gastrointest Endosc 2010; 72: 1020-1026
• 9 Ellrichmann M, Dhar S, Sethi A et al. Systematic Evaluation of the Efficacy and Safety of Different Anti-Infective Methods for Transgastric Notes Procedures: A Randomised Controlled Trial in a Porcine Survival Model. Gastrointestinal Endoscopy 2012; 75: AB273 DOI: 10.1016/j.gie.2012.03.692.