Background and study aims: Secure transluminal closure is the most fundamental prerequisite for the safe introduction of natural orifice transluminal endoscopic surgery (NOTES). The aim was to compare acute strength of various gastrotomy closure techniques in an in vitro porcine stomach model by assessing leak pressures.
Methods: Standardized gastrotomies were closed manually, without the use of an endoscope, by one of seven NOTES closure devices: (i) T tags, (ii) purse string modified T tags, (iii) Eagle Claw VIII, (iv) Resolution clips, (v) flexible stapler; (vi) purse string suturing device, and (vii) flexible Endostitch. After closure, each specimen was fixed on the experimental apparatus and the pressure was gradually increased. By linking the pressure gauge and two cameras, the leak location and pressure could be determined in detail. We began by collecting gold standard reference values, by testing 15 gastrotomies closed with interrupted surgical sutures; these were associated with a mean leak pressure of 206 mmHg (SD 59). Using a noninferiority design, a sample size of 11 specimens for each NOTES closure technique was determined.
Results: The Resolution clips ( P = 0.0285), Eagle Claw VIII ( P = 0.0325), flexible stapler ( P < 0.001) and flexible Endostitch ( P = 0.002) produced noninferior closures in comparison with the predetermined gold standard; T tags ( P > 0.6775), purse string modified T tags ( P > 0.999), and the purse string suturing device ( P = 0.9875) resulted in inferior closures.
Conclusions: The Eagle Claw VIII, Resolution clips, flexible stapler and flexible Endostitch produced noninferior closures in comparison with surgical closure in this model. These techniques seem to be the prime candidates for further testing in animal experiments before human trials can be initiated.