Abstract: Objective     To observe the anesthetic effect of different induced anaesthetics LumianningⅡ or ketamine combined with propofol for peroral natural orifice transluminal endoscopic surgery across the stomach wall and into the abdomen for bracket placement to remove gallstone with gallbladder preservation in experimental pigs. Methods    Sixteen Bama miniature pigs were randomly divided into two groups. The anesthesia was induced in the pigs with Lumianning II (group A) or ketamine (group B), and maintained with propofol during the operation. The vital signs, intraoperative conditions, anesthesia induction time, surgical time, recovery time and propofol dosage in the two groups were compared. Results    The anesthesia of two groups went smoothly. For the two groups, the differences of the average heart rate, average respiratory rate, average blood oxygen saturation, the average systolic blood pressure and the average diastolic blood pressure before, during and after surgery were not statistically significant (all P＞0.05). The average body temperature during surgery was lower than that before and after surgery, the difference was statistically significant (P＜0.05). The incidence of mild body movements in group A was 25.0%, and that in group B was 37.5%. Three experimental pigs in group A showed convulsions during the operation, but none in group B. The difference was not statistically significant (P＞0.05). The average induction anesthesia time, average operation time, average recovery time and average total dosage of propofol between group A and group B were not statistically significant (all P＞0.05). Conclusion     LumianningⅡ- or ketamine-induced anesthesia and propofol maintenance can be used in the experimental pigs to achieve safe anesthetic effect during the natural orifice transluminal endoscopic surgery approaching for gallstone removal. The ketamine group has shorter induction time with no convulsions. This study can be a value of reference for clinical practice. 

Key words: Ketamine, Lumianning II, Natural orifice transluminal endoscopic surgery,  , Microinvasive gallbladder-protected lithotomy, Experimental pigs ,