Comparative study of NOTES alone vs. EUS-guided NOTES procedures

Natural-orifice transluminal endoscopic surgery (NOTES) is in the developmental stage for various indications, but several obstacles remain to be overcome before NOTES procedures can come into routine clinical use. Of these obstacles, (1) transluminal injury due to exclusive use of endoluminal endoscopy to create the incision and (2) lack of orientation might be prevented by employing endoscopic ultrasound guidance. In this comparative study we assessed the role of endoscopic ultrasound guidance in various NOTES procedures.

Three transesophageal (mediastinoscopy/thoracoscopy) or transgastric procedures (gastrojejunostomy, adrenal gland removal) were performed in pigs using NOTES alone or with endoscopic ultrasound guidance (EUS). In NOTES alone the study end point was three major complications, at which point EUS guidance was added for the same procedures up to the same number of cases. The primary outcome was the rate of major complications; secondary outcome parameters were all complications and technical success.

Forty-six pigs were included. Three major complications occurred in the first 24 NOTES-alone procedures: these were bleeding and organ injury, all during mediastinoscopy/thoracoscopy procedures. Adrenal gland removal failed in all procedures in which it was attempted, while gastrojejunostomy (n = 6) was performed successfully and without complications. In the next 22 animals EUS guidance enabled safe mediastinal access (n = 10) and adrenal gland removal (n = 6). For gastrojejunostomy, EUS guidance offered no additional benefit.

EUS guidance appears to be helpful in gaining access or identifying structures in anatomically difficult areas in NOTES procedures.