Which surgical procedure involves an incision into the common bile duct?

The surgical procedure that involves making an incision into the common bile duct is known as choledochotomy. This procedure is typically performed to access the bile duct for various reasons, such as removing stones, draining bile in cases of obstruction, or obtaining a biopsy.

Choledochotomy enables surgeons to directly treat issues within the common bile duct while minimizing damage to surrounding structures. By gaining access through the duct, the surgical team can address biliary issues effectively, which is critical in conditions like choledocholithiasis (the presence of stones in the bile duct) or strictures (narrowing of the duct).

The other procedures listed do not involve the common bile duct. Pyloromyotomy pertains to the surgical division of the pylorus to alleviate gastric outlet obstruction, herniorrhaphy is the surgical repair of a hernia, and cystectomy involves the surgical removal of all or part of the urinary bladder. Only choledochotomy relates specifically to making an incision in the common bile duct, making it the correct answer.