Anatomy of NOTES gastrotomy in human tissue

Background: Transoral natural orifice translumenal endoscopic surgery (NOTES) procedural success depends on a secure gastrotomy closure. Balloon gastrotomy is the most common technique to date, but the stomach-layer defect sizes and their relationship in human tissue has not been determined. Methods: Ten 2-cm diameter controlled radial expansion balloon gastrotomies were performed in ex vivo human tissue. All gastrotomies were located on the anterior stomach wall. The main axis of the elliptical-shaped serosal and longitudinal muscle layer opening, the mucosal opening, and the circular muscle layer opening (after removal of mucosa) was measured. All steps were photo documented and electronically analyzed for common opening size. Results: The average common opening was 1 ± 0.6 to 1.3 cm, although the main axis of a single layer can be as long as 2.2 cm. The average serosal/longitudinal muscle layer defect measured 1.5 cm, the average mucosal defect 1.6 cm, and the average circular muscle layer defect 1.5 cm. Conclusion: These findings on NOTES gastrotomy anatomy demonstrate the complexity of the stomach wall opening and the challenge of providing a fail-safe gastrotomy closure. Further in vivo human studies are advised.