A novel catheter design for laser photocoagulation of the myocardium to ablate ventricular tachycardia.
A novel catheter design for laser photocoagulation of the myocardium to ablate ventricular tachycardia.
复制标题
一种新颖的导管设计，用于心肌激光光凝消融室性心动过速。
DOI：
10.1023/a:1020859814224
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
Huang,SKStephen
中科院分区：
文献类型：
--
作者：
Wagshall,Alan;Abela,GeorgeS;Maheshwari,Alok;Gupta,Anoop;Bowden,Russell;Huang,SKStephen
Nd:YAG laser energy has been proposed as an alternative to radiofrequency energy for ablation of ventricular tachycardia (VT) associated with coronary artery disease (CAD) in an effort to increase lesion size and success rates. However, issues of catheter design to maintain flexibility and ensure adequate tissue contact have hindered development of laser catheters.We developed and tested a prototype 8 Fr. steerable catheter with a flexible and extendible tip (designed to ensure tissue contact and efficient ventricular mapping), which projects the laser beam through a side port containing a lens-tipped optical fiber that rests against the endocardial surface. The catheter has a channel for simultaneous saline irrigation to displace the interceding blood and discharge a laser beam between two electrodes for bipolar mapping and a thermocouple for temperature monitoring. The catheter was tested on bench top using the epicardial surface of freshly slaughtered bovine hearts andin vivousing six anaesthetized closed-chest sheep.In vitroexperiments demonstrated that lesion size increased linearly with applied power up to 40 watts. When compared to radio frequency, laser energy penetrated more deeply into the myocardium. In thein vivostudies, using increasing powers of up to 40 watts for application times of 60 to 120 seconds created circular or elliptical lesions with surface dimensions up to 12 mm × 12 mm and depth of 9 mm (full LV wall thickness with a mean lesion diameter of 9.9 ± 5.2 mm and depth 5.8 ± 3.2 mm). Most lesions, 16 total in both right and left ventricular walls were transmural or near transmural in thickness. Lesions demonstrated coagulation necrosis with smooth well-demarcated borders. No animal suffered cardiac perforation, hypotension, hemopericardium, damage to cardiac valves, or cavitation effect from any of the ablations. Runs of VT were seen during energy application at the highest laser outputs in two animals.In conclusion, this catheter design provides effective endocardial delivery of laser energy and is capable of creating transmural or nearly transmural lesionsin vivoandin vitro, thereby potentially increasing the efficiency of VT ablation in CAD patients.
