Argon plasma coagulation is a surgical procedure used to stop bleeding without touching the tissue being targeted. Used as an alternative to cauterizing blood vessels or using a laser, the process involves the use of a probe that fires argon gas, which closes an electrical current when it hits biological tissues. The tip of the device can be located up to 0.39 inches (1 centimeter) above the surface, and the thermal energy can cut up to 0.78 to 1.18 inches (2 to 3 centimeters) deep. This procedure is used to stop bleeding during surgery or endoscopic procedures, break up tumors, and clear tissue growth from stents.
The heat from argon plasma coagulation evaporates water from in and around cells in the area. It also alters protein such that coagulation occurs on the spot. In addition to the probe, there is a tungsten wire just inside the probe that is capable of producing 6,000 volts of electricity, which creates an ignition source and ionizes the argon gas. A surgical cart used during the procedure also includes an electrosurgical generator, argon gas tanks, a foot pedal, and a control panel. It is possible for power levels to be adjusted during coagulation and for the argon flow to be increased to move debris or residual blood out of view.
During argon plasma coagulation, physicians will place a grounding pad on the patient’s lower back in order to protect them from electric shock. The gas is fired at just two or three seconds at a time from a probe that is 0.09 inches (2.3 millimeters) in diameter, but it could be fired for longer intervals to reach deeper, clot massive bleeding, or break up large tumors. Lesions do not always have to be in direct view, and bleeding can be stopped that is not directly in front of a scope or which is around a fold in tissue.
Rare complications have occurred with argon plasma coagulation, including induction of pneumonia-like conditions when it is used in the airways and lungs. Fires in the airway are rare, and burns from the scope instrument can be prevented by avoiding contact between it and the gas probe. In addition to operations involving the airways, argon plasma coagulation has been used in the upper and lower gastrointestinal tracts to remove both tumors and polyps. The low penetration depth of argon plasma coagulation may result in better safety over alternative procedures.