Catheter ablation technique

Catheters, in their simplest form, are merely tubes inserted into a body cavity for die purpose of fluid removal, injection, or both (Thomas, 1989). The term catheter has been expanded to include a number of tubing-based percutaneous interventional devices used for tasks such as stent delivery and deployment, clot removal, radio-frequency ablation, and intra-aortic balloon cardiac support Because of their prevalence and representative uses, the present section will be limited to vascular infusion catheters and access ports. Stenting and cardiac support applications utilizing catheter-based techniques are discussed elsewhere in this chapter. 

Ouyang F, Ernst S, Chun J, et al. Electrophysiological findings during ablation of persistent atrial fibrillation with elec-troanatomic mapping and double Lasso catheter technique. 

Through catheters it is possible to destroy tissue with RF currents in a minimally invasive procedure. In cardiology, this is called ablation. Both DC and RF current have been tried for this purpose. Choice of bipolar or monopolar technique is important, Anfinsen et al. (1998). 

Anfinsen, O.-G., Kongsgaard, E., Eoerster, A., Aass, H., AmUe, J.R., 1998. Radio frequency current ablation of porcine right atrium Increased lesion of bipolar two catheter technique compared to unipolar appUcation in vitro and in vivo. Racing Clin. Electrophysiol. 21, 69—78. 

The details of the laser and RF treatments vary at this point but the ultimate treatment goals and techniques are similar. With RF ablation, the RF catheter is withdrawn only after its tines are exposed to allow contact with the vein wall. The catheter is withdrawn maintaining the vein wall temperature at or above 85°C as measured by a thermocouple embedded in its tip. For laser ablation the fiber is withdrawn at a rate determined by the energy deposition per length of vein treated. For the remainder of this presentation on technique, the laser procedure will be discussed. The details of the RF venous ablation can be reviewed in the references cited in the results section. 

---