Common bile duct is dilated

Ultrasound report says: Probable sludge and small stones in the gallbladder. Dilated common bile duct measuring 9mm concerning for a distal obstruction.

[Caryopteris]

The radiologist is saying a stone may have gone up the common bile duct, causing the dilation, and putting you at risk for common bile duct obstruction.  That can be a painful complication of gallstones.  Talk to your surgeon about what he suggests.