This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gall Bladder & Bile Ducts, Subject name: Surgery
[{'content': 'A 3 cm size stone in CBD near the ampulla of Vater is removed by \nSelect and explain. \nA. Trans duodenal approach, B. Supraduodenal approach, C. Chemical dissolution, D. ESWL', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. (a) Transduodenal ApproachRef: Sabiston 20th edition Page 1501Impacted stones at the ampulla that cannot be removed through choledochotomy or several stones in a nondilated tree can be addressed by a transduodenal sphincteroplastySteps:* Kocher maneuver,* Longitudinal duodenotomy is made on the lateral wall* Palpation of the ampulla to plan placement of the duodenotomy* After identifying ampulla- an incision made at 11' O clock* Avoid 5'O clock as pancreatic duct enters there.* The duodenal mucosa is sewn to the bile duct mucosa with absorbable 4-0 sutures.* A 1.5cm sphincterotomy is usually sufficient to allow stone removal and subsequent drainage.* Closure of the longitudinal duodenotomy in transverse fashion to avoid future duodenal stricture.", 'role': 'assistant'}]