Abstract:

Objective To investigate the safety of gallbladder-preserving cholelithotomy via natural orifice transluminal endoscopic surgery （NOTES） and the feasibility of the transgastric tunnel approach. Methods Six miniature pigs weighing 18±2 kg were selected， and gallstone models were established by feeding method. The miniature pigs with successful modeling were randomly divided into tunnel group （submucosal tunnel approach） and control group （layered gastric wall incision approach） using a random number table method， with 3 miniature pigs in each group. Both groups of miniature pigs entered the abdominal cavity through an incision in the anterior wall of the gastric antrum， underwent cholecystotomy and stone removal， and then the gallbladder and gastric wall incisions were closed with metal clips. The surgical time， blood loss， and occurrence of complications in the two groups of miniature pigs were recorded. Incision healing was observed by anatomical dissection at 1 month postoperatively. White blood cell （WBC） count， C-reactive protein （CRP） level， and total bilirubin （TBIL） level， and alanine aminotransferase （ALT） and aspartate aminotransferase （AST） activities in the serum of the miniature pigs were detected at 30 min before surgery， 24 and 72 h postoperatively， and 1 month postoperatively. Results All 6 miniature pigs successfully completed the surgery. Gallstones （1-3 stones with diameters of approximately 1-8 mm） were successfully formed in 67% （4/6） of the model miniature pigs. Compared with control group， the gastric wall incision time in tunnel group was significantly increased （P<0.05）. Compared with control group， the blood loss from gastric wall incision was less in tunnel group， but no statistically significant difference was observed （P>0.05）. Compared with control group， the time required for gastric wall closure was significantly decreased in tunnel group （P<0.05）， and the number of metal clips used was significantly decreased （P<0.05）. No serious complications occurred in the miniature pigs in two groups postoperatively， and anatomical dissection at 1 month postoperatively showed good incision healing. For laboratory indicators， compared with those at preoperative 30 min， the WBC count and CRP level in the serum of the miniature pigs were significantly increased at 24 h postoperatively （P<0.01）. At 72 h postoperatively， the WBC count in the serum of the miniature pigs returned to normal， while the CRP level remained significantly increased （P<0.01）. Compared with those at preoperative 30 min， no statistically significant differences were observed in TBIL levels or ALT and AST activities of the miniature pigs at any postoperative time point （P>0.05）. Conclusion Transgastric NOTES gallbladder-preserving cholelithotomy is safe and feasible. The tunnel approach shows advantages in reducing bleeding and facilitating gastric wall incision closure.

Key words: Gallstone, Gallbladder-preserving cholelithotomy, Natural orifice transluminal endoscopic surgery, Tunnel technique, Disease model