Transrectal robotic natural orifice translumenal endoscopic surgery (NOTES) applied to intestinal anastomosis in a porcine intestine model

Natural orifice translumenal endoscopic surgery (NOTES) is a minimally invasive operation using devices such as flexible endoscopes and linear or circular staplers. Nevertheless, hand-sewn anastomosis in NOTES remains challenging. This study aimed to investigate the feasibility of transrectal robotic NOTES requiring intracorporeal small intestinal anastomosis and closure of the rectal anterior wall incision in a relevant human model. The authors developed a flexible rectal proctoscope with a diameter of 43 mm for transrectal robotic NOTES. Small intestinal anastomosis was performed in a porcine intestinal transrectal NOTES model using two robotic arms and a camera inserted through the proctoscope and a rectal anterior wall incision. The quality of transrectal small intestinal anastomosis using the da Vinci surgical system (transrectal robotic NOTES group) was compared with that of transabdominal anastomosis using the da Vinci surgical system (transabdominal robot-assisted surgery group) and transrectal anastomosis using traditional transanal endoscopic microsurgery (TEM) instruments (TEM NOTES group). The quality of transrectal rectal anterior wall suturing in the transrectal robotic NOTES group was compared with that of the TEM NOTES group and the open surgical instruments group (open group). Robotic intracorporeal suturing was performed successfully in the porcine intestine model. During small intestinal anastomosis, burst pressure in the transrectal robotic NOTES group (67.7 +/- A 29.3 mmHg) was similar to that in the transabdominal robot-assisted surgery group (73.3 +/- A 18.2 mmHg) but significantly higher than in the TEM NOTES group (20.3 +/- A 24.0 mmHg; p < 0.01). During rectal anterior wall suturing, the burst pressure did not differ significantly between the transrectal robotic NOTES group (149.9 +/- A 81.1 mmHg) and the open group (195.0 +/- A 60.5 mmHg). The preliminary safety and efficacy of transrectal robotic NOTES was established. Further studies are required to determine the practical feasibility of this procedure.