Relationship Between Catheter Forces, Lesion Characteristics, “Popping,” and Char Formation: Experience with Robotic Navigation System

• DOI: 10.1111/j.1540-8167.2008.01355.x
• Publication Date: 2008-11-11T20:30:24Z
• Authors: LUIGI DI BIASE; ANDREA NATALE; CONOR BARRETT; CARMELA TAN; CLAUDE S. ELAYI; CHI KEONG CHING; PAUL WANG; AMIN AL‐AHMAD; MAURICIO ARRUDA; J. DAVID BURKHARDT; BRIAN J. WISNOSKEY; PUNAM CHOWDHURY; SHARI DE MARCO; LUCIANA ARMAGANIJAN; KENNETH N. LITWAK; ROBERT A. SCHWEIKERT; JENNIFER E. CUMMINGS
• Keywords: Male; Equipment Design; Robotics; Risk Assessment; 03 medical and health sciences; Dogs; 0302 clinical medicine; Heart Injuries; Surgery, Computer-Assisted; Materials Testing; Catheter Ablation; Pressure; Animals; Female; Stress, Mechanical; Endocardium; Ultrasonography

Introduction: Popping, char and perforation are complications that can occur following catheter ablation. We measured the amount of grams (g) applied to the endocardium during ablation using a sensor incorporated in the long sheath of a robotic system. We evaluated the relationship between lesion formation, pressure, and the development of complications. Methods: Using a robotic navigation system, lesions were placed in the left atrium (LA) at six settings, using a constant duration (40 seconds) and flow rate of either 17 cc/min or 30 cc/min with an open irrigated catheter (OIC). Evidence of complications was noted and lesion location recorded for later analysis at necropsy. Results: Lesions using 30 Watts (W) were more likely to be transmural at higher (>40 g) than lower (<30 g) pressures (75% vs 25%, P < 0.001). Significantly higher number of lesions using >40 g of pressure demonstrated “popping” and crater formation as compared with lesions with 20–30 g of pressure (41% vs 15%, P = 0.008). A majority of lesions placed using higher power (45 W) with higher pressures (>40 g) were associated with char and crater formation (66.7%). No lesions using 10 g of pressure were transmural, regardless of the power. Lesions placed with a power setting less than 35 W were more likely to result in “relative” sparing of the endocardial surface than lesions at a power setting higher than 35 W (62% vs 33.3%, P = 0.02) regardless of the pressure. Conclusions: When using an OIC, lower power settings (≤35 W) and lower/medium contact pressure were more likely to show a “relative” spared endocardial surface. Overall, contact pressure between 20 g and 30 g and a power setting of 40 W appeared to achieve transmurality by preserving safety.