Introduction: Migration of stones from the gallbladder to the cystic duct has been reported in up to 15% of cases during laparoscopic cholecystectomy, with significant risk of residual choledocholithiasis. Additionally, gallbladder dissection is occasionally difficult due to adherence to the liver, with increased risk of bleeding and perforation. Poloxamer 407 is a non-ionic surfactant with rapid reversible sol-gel transition (solid at body temperature, liquid at cold temperatures), behavior that has been used to prevent ureteral stone migration in animal studies. Aim: To investigate a reverse phase polymer as a method of stabilizing stones in the gallbladder during cholecystectomy and as a means of tissue dissection in NOTES.
Methods: A partial NOTES cholecystectomy was performed in 2 non-survival using a double-channel endoscope via a transcolonic approach. The procedural steps were as follows: identification and exposure of the gallbladder; filling of the gallbladder with the polymer; injection of the polymer between the gallbladder and the liver, and dissection of the gallbladder from its bed. For the polymer injection we used a 22-G endoscopic needle. Poloxamer 407 was kept on ice during the intervention. Saline containing syringes were also kept on ice to cool the catheter immediately before poloxamer injections. Animals were sacrificed immediately after the surgery and necropsy performed.
Results: The gallbladder was able to be filled until distention was observed. No leakage of bile following needle withdrawal was noted, confirming gel occlusion. Injection between the gallbladder and liver was feasible and appeared to aid in gallbladder resection. At necropsy, 25 minutes after the polymer was injected, the gallbladder was filled by a yellow gel that confirmed the polymer had mixed with bile and remained in the solid phase. No polymer was identified in the cystic duct. The surgical bed did not show bleeding and there was a gel interface between the remaining gallbladder and the fossa allowing an easy manual separation of both structures.
Conclusions: The use of a reverse phase polymer for cholecystectomy may prevent the leakage of bile in the case of a gallbladder perforation and the migration of stones through the cystic duct. Additionally, this may facilitate the dissection of the gallbladder from the fossa.