Biophysical characteristics of radiofrequency lesion formation in vivo: Dynamics of catheter tip–tissue contact evaluated by intracardiac echocardiography

Kalman, Jonathan M.; Fitzpatrick, Adam P.; Olgin, Jeffrey E.; Chin, Michael C.; Lee, Randall J.; Scheinman, Melvin M.; Lesh, Michael D.

doi:10.1016/s0002-8703(97)70242-4

Cited by 139 publications

(105 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Angle of contact has been explored as a statistically significant factor in lesion formation [73], and orientation control of the continuum manipulator would provide additional variables for describing desired paths (e.g. where controlling angled contact would be more conducive for \dragging").…”

Section: Discussionmentioning

confidence: 99%

Autonomous Control of Continuum Robot Manipulators for Complex Cardiac Ablation Tasks

Yip

Sganga

Camarillo

2017

J. Med. Robot. Res.

View full text Add to dashboard Cite

Continuum manipulators enable minimally-invasive surgery on the beating heart, but the challenges involved in manually controlling the manipulator's tip position and contact force with the tissue result in failed procedures and complications. The objective of this work is to achieve autonomous robotic control of a continuum manipulator's position and force in a beating heart model. We present a model-less hybrid control approach that regulates the tip position/force of manipulators with unknown kinematics/ mechanics, under unknown constraints along the manipulator's body. The algorithms estimate the Jacobian in the presence of heartbeat disturbances and sensor noise in real time, enabling closed-loop control. Using this model-less control approach, a robotic catheter autonomously traced clinically relevant paths on a simulated beating heart environment while regulating contact force. A gating procedure is used to tighten the treatment margins and improve precision. Experimental results demonstrate the capabilities of the robot (1:4 AE 1:1 mm-1:9 AE 1:4 mm tracking error) while user demonstrations show the difficulty of manually performing the same task (2:6 AE 2:0 mm-4:3 AE 3:9 mm tracking error). This new, robotically-enabled contiguous ablation method could reduce ablation path discontinuities, improve consistency of treatment, and therefore improve clinical outcomes.

show abstract

Section: Discussionmentioning

confidence: 99%

Autonomous Control of Continuum Robot Manipulators for Complex Cardiac Ablation Tasks

Yip

Sganga

Camarillo

2017

J. Med. Robot. Res.

View full text Add to dashboard Cite

show abstract

“…3,17,18 Intuitively, successful lesion formation is related to the amount of RF energy transmitted to the prospective lesion site, and is a function of contact force, contact surface area, application time, and application power. Real-time operative parameters to date have considered CF and application time (combined in FTI); however, LSI also incorporates power along with CF and time in a nonlinear fashion to provide a novel dimensionless parameter to guide ablation techniques.…”

Section: Discussionmentioning

confidence: 99%

Lesion Size Index in Maximum Voltage-Guided Cavotricuspid Ablation for Atrial Flutter

Boles

Gül

Fitzpatrick

et al. 2017

JICRM

View full text Add to dashboard Cite

ABSTRACT. The application of optimum contact force (CF) can be used to improve ablation procedure success and safety. The lesion size index (LSI) is a novel dimensionless contact force parameter that allows for an accurate estimation of lesion volume in real time by integrating contact force (grams), duration (seconds) and power (watts). The aim was to correlate LSI values with current contact force parameters to achieve successful and safe bidirectional block of the cavotricuspid isthmus (CTI) using a maximum voltage-guided (MVG) ablation strategy. Fifteen consecutive patients (age 69±7.9 years, nine males) with symptomatic atrial flutter (AFL) were evaluated and compared with 23 control (age 66.3 ± 10.4 years, 16 males) non-contact forceguided ablation cases. Irrigated-tip force-sensing ablation catheters (TactiCath Quartzt, St. Jude Medical, St. Paul, MN, USA) were used in the CF group to achieve the primary endpoint of complete bidirectional block of the isthmus. In the CF group, a total of 233 radiofrequency (RF) applications were examined. A mean LSI of 6.4 ± 1.0 correlated with a force-time integral (FTI) of 581.2±230.9 g/s and an average CF of 13.9±4.9 g concurrently. Intraprocedural, fluoroscopy time and RF time demonstrated lower trends in the CF group, but no significance with respect to these trends was observed. The secondary endpoint of no reconnection within 20 min after the procedure was equally attained in both groups, and, likewise, the level of safety was comparable. An LSI value of 45 represents a new effective parameter in MVG ablation for the cavotricuspid region that demonstrates a safe profile. Guidance of CTI ablation using LSI and other contact force parameters of CF 13.9 ± 4.9 g and FTI 581.2 ± 230.9 g/s demonstrated highly effective and safe outcomes.

show abstract

“…Formation of a few scattered microbubbles is believed to reflect the early manifestation of overheating. 18,19 When this occurs, energy has to be gradually decreased until their generation subsides. However, if this phenomenon cannot be controlled and progresses, tissue desiccation will result, creating the milieu for coagulum formation and PV stenosis.…”

Section: Importance Of Energy Titrationmentioning

confidence: 99%

Pulmonary Vein Stenosis After Radiofrequency Ablation of Atrial Fibrillation

et al. 2003

View full text Add to dashboard Cite

Background-Pulmonary vein (PV) stenosis is a complication of ablation for atrial fibrillation. The impact of different ablation strategies on the incidence of PV stenosis and its functional characterization has not been described. Methods and Results-PV isolation was performed in 608 patients. An electroanatomic approach was used in 71 and circular mapping in 537 (distal isolation, 25; ostial isolation based on PV angiography, 102; guided by intracardiac echocardiography, 140; with energy delivery based on visualization of microbubbles, 270). Severe (Ն70%) narrowing was detected in 21 patients (3.4%), and moderate (50% to 69%) and mild (Ͻ50%) narrowing occurred in 27 (4.4%) and 47 (7.7%), respectively. Severe stenosis occurred in 15.5%, 20%, 2.9%, 1.4%, and 0%, respectively. Development of symptoms was correlated with involvement of Ͼ1 PV with severe narrowing (Pϭ0.01), whereas all patients with mild and moderate narrowing were asymptomatic. In the latter group, lung perfusion (V/Q) scans were normal in all but 4 patients. All patients with severe stenosis had abnormal perfusion scans. Conclusions-V/Q scans are useful to assess the functional significance of PV stenosis. Mild and moderate degrees of PV narrowing are not associated with development of symptoms and seem to have no or minimal detrimental effect on pulmonary flow. The incidence of severe PV stenosis seems to be declining with better imaging techniques to ensure ostial isolation and to guide power titration. Mild narrowing 3 months after ablation does not preclude future development of severe stenosis and should be assessed with repeat imaging studies. (Circulation. 2003;108:3102-3107.)

show abstract

Biophysical characteristics of radiofrequency lesion formation in vivo: Dynamics of catheter tip–tissue contact evaluated by intracardiac echocardiography

Cited by 139 publications

References 14 publications

Autonomous Control of Continuum Robot Manipulators for Complex Cardiac Ablation Tasks

Autonomous Control of Continuum Robot Manipulators for Complex Cardiac Ablation Tasks

Lesion Size Index in Maximum Voltage-Guided Cavotricuspid Ablation for Atrial Flutter

Pulmonary Vein Stenosis After Radiofrequency Ablation of Atrial Fibrillation

Contact Info

Product

Resources

About