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-1990s, 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 POEMprocedures 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.