Cholcdochoscopy not only permits visualization of the inside of the common bile duct and its calculi, hut also facilitates their removal. Choledochoscopcs have been perfected in recent years. Accessories have been added to choledochoscopes for the removal of calculi and for the performance of biopsies.
There are basically two principal models of choledochoscopes: a rigid model and a flexible model. The rigid model is composed of a longitudinal stem and another horizontal stem connected at right angle. The horizontal portion may he 4 to 6 cm long.
This instrumenr is easy to manipulate and gives excellent visualization. The flexible model is more complex and somewhat more difficult to manipulate, but it has the advantage tnat it can be introduced into the common heparic duct and its principal branches. This instrument can also be introduced into the common bile duct through the papilla.
To he able to visualize the inside of the common bile duct it is indispensable to dilate it with a flow of physiologic saline during the examinarion.
The best application for choledochoscopy is in patients with intrahepatic lirhiasls and patients with multiple stones. Some surgeons have replaced control operative cholangiography at the end of the procedure, through the Tvtube, with cholcdochoscopy.
Some of the reasons given by these surgeons are these:
- A control cholangiogram with the Tube in place is dilficul: to interpret due to the frequent presence of air bubbles in the common bile duct.
- Control cholangiography performed after the removal of calculi and exploration of the papilla frequently reveals spasm of the sphincter of Oddi, which makes interpretation difficult.
The first objection, the presence of air bubbles, is a technical fault that is easy to avoid if habitual care is taken. In relation to the second objection, spasm of the sphincter of Oddi, it is not produced if the papilla is explored very carefully. Spasm of the papilla occurs if forced dilations of the papilla are carried out or if exploring instruments are passed several limes through the papilla, traumatizing the papilla, or when false tracts have been produced. Exploration of the papilla should be performed with plastic or woven silk explorers with conical ends.
The papilla should never be dilated. zr a 5 mm explorer passes through the papilla il is enough to show that the papilla is permeable.
In recent years video choledochoscopy has been added to the methods of exploration of the common bile duct. This exploratory method permits the vision of the interior of the common bile duct by all the members of the surgical team through the television screen, greatly facilitating complementation of the maneuvers between the surgeon and his or her assistants for the removal of calculi.