Transcatheter electrosurgery refers to a family of procedures using radiofrequency energy to vaporize and traverse or lacerate tissue despite flowing blood. The authors review theory, simulations, and benchtop demonstrations of how guidewires, insulation, adjunctive catheters, and dielectric medium interact. For tissue traversal, all but the tip of traversing guidewires is insulated to concentrate current. For leaflet laceration, the “Flying V” configuration concentrates current at the inner lacerating surface of a kinked guidewire. Flooding the field with non-ionic dextrose eliminates alternative current paths. Clinical applications include traversing occlusions (pulmonary atresia, arterial and venous occlusion, and iatrogenic graft occlusion), traversing tissue planes (atrial and ventricular septal puncture, radiofrequency valve repair, transcaval access, Potts and Glenn shunts), and leaflet laceration (BASILICA, LAMPOON, ELASTA-Clip, and others). Tips are provided for optimizing these techniques. Transcatheter electrosurgery already enables a range of novel therapeutic procedures for structural heart disease, and represents a promising advance toward transcatheter surgery.
by
Philippe Genereux;
Philippe Pibarot;
Bjorn Redfors;
Michael J. Mack;
Raj R. Makkar;
Wael A. Jaber;
Lars G. Svensson;
Samir Kapadia;
E. Murat Tuzcu;
Vinod Thourani;
Vasilis Babaliaros;
Howard C. Herrmann;
Wilson Y. Szeto;
David Jay Cohen;
Brian R. Lindman;
Thomas McAndrew;
Maria C. Alu;
Pamela S. Douglas;
Rebecca T. Hahn;
Susheel K. Kodali;
Craig R. Smith;
D. Craig Miller;
John G. Webb;
Martin B. Leon
Aims In patients with aortic stenosis (AS), risk stratification for aortic valve replacement (AVR) relies mainly on valverelated factors, symptoms and co-morbidities. We sought to evaluate the prognostic impact of a newly-defined staging classification characterizing the extent of extravalvular (extra-aortic valve) cardiac damage among patients with severe AS undergoing AVR. Methods and results Patients with severe AS from the PARTNER 2 trials were pooled and classified according to the presence or absence of cardiac damage as detected by echocardiography prior to AVR: no extravalvular cardiac damage (Stage 0), left ventricular damage (Stage 1), left atrial or mitral valve damage (Stage 2), pulmonary vasculature or tricuspid valve damage (Stage 3), or right ventricular damage (Stage 4). One-year outcomes were compared using Kaplan- Meier techniques and multivariable Cox proportional hazards models were used to identify 1-year predictors of mortality. In 1661 patients with sufficient echocardiographic data to allow staging, 47 (2.8%) patients were classified as Stage 0, 212 (12.8%) as Stage 1, 844 (50.8%) as Stage 2, 413 (24.9%) as Stage 3, and 145 (8.7%) as Stage 4. Oneyear mortality was 4.4% in Stage 0, 9.2% in Stage 1, 14.4% in Stage 2, 21.3% in Stage 3, and 24.5% in Stage 4 (Ptrend < 0.0001). The extent of cardiac damage was independently associated with increased mortality after AVR (HR 1.46 per each increment in stage, 95% confidence interval 1.27-1.67, P < 0.0001). Conclusion This newly described staging classification objectively characterizes the extent of cardiac damage associated with AS and has important prognostic implications for clinical outcomes after AVR.
by
Brian R. Lindman;
Alan Zajarias;
Hersh S. Maniar;
D. Craig Miller;
Rakesh M. Suri;
Suzanne V. Arnold;
John Webb;
Lars G. Svensson;
Susheel Kodali;
Ke Xu;
Girma M. Ayele;
Fay Lin;
Shing-Chiu Wong;
Vasilis Babaliaros;
Vinod Thourani;
Pamela V. Douglas;
Scott Lim;
Martin B. Leon;
Michael J. Mack
Objective: Pulmonary hypertension (PH) is associated with increased mortality after surgical or transcatheter aortic valve replacement (TAVR) for aortic stenosis (AS), and when the pulmonary artery pressure is particularly elevated, there may be questions about the clinical benefit of TAVR. We aimed to identify clinical and haemodynamic factors associated with increased mortality after TAVR among those with moderate/severe PH.
Methods: Among patients with symptomatic AS at high or prohibitive surgical risk receiving TAVR in the Placement of Aortic Transcatheter Valves (PARTNER) I randomised trial or registry, 2180 patients with an invasive measurement of mean pulmonary artery pressure (mPAP) recorded were included, and moderate/severe PH was defined as an mPAP ≥35 mm Hg.
Results: Increasing severity of PH was associated with progressively worse 1-year all-cause mortality: none (n=785, 18.6%), mild (n=838, 22.7%) and moderate/severe (n=557, 25.0%) (p=0.01). The increased hazard of mortality associated with moderate/severe PH was observed in females, but not males (interaction p=0.03). In adjusted analyses, females with moderate/severe PH had an increased hazard of death at 1 year compared with females without PH (adjusted HR 2.14, 95% CI 1.44 to 3.18), whereas those with mild PH did not. Among males, there was no increased hazard of death associated with any severity of PH. In a multivariable Cox model of patients with moderate/severe PH, oxygen-dependent lung disease, inability to perform a 6 min walk, impaired renal function and lower aortic valve mean gradient were independently associated with increased 1-year mortality (p<0.05 for all), whereas several haemodynamic indices were not. A risk score, including these factors, was able to identify patients with a 15% vs 59% 1-year mortality.
Conclusions: The relationship between moderate/severe PH and increased mortality after TAVR is altered by sex, and clinical factors appear to be more influential in stratifying risk than haemodynamic indices. These findings may have implications for the evaluation of and treatment decisions for patients referred for TAVR with significant PH.
by
Jean-Michel Paradis;
Hersh S. Maniar;
John M. Lasala;
Susheel Kodali;
Mathew Williams;
Brian R. Lindman;
Ralph J. Damiano;
Marc R. Moon;
Marc R. Makkar;
Vinod Thourani;
Vasilis Babaliaros;
Ke Xu;
Girma Minalu Ayele;
Lars Svensson;
Martin B. Leon;
Alan Zajarias
Objectives This study sought to clarify the clinical and echocardiographic prognostic implication of myocardial injury after transcatheter aortic valve replacement (TAVR). Background The clinical significance of cardiac biomarker elevation after TAVR remains unclear. Methods Patients treated with TAVR in the PARTNER (Placement of Aortic Transcatheter Valves) trial were divided into tertiles (T1, T2, T3) based on the difference between the values on post-procedure day 1 and the baseline values of 2 cardiac biomarkers: cardiac troponin I (ΔcTnI); and creatine kinase-myocardial band (ΔCK-MB) fraction. Patients were stratified according to their access route: transfemoral (TF) (n = 1,840) or transapical (TA) (n = 1,173). Results At 30 days after TF-TAVR, patients in the highest tertile (T3) of cardiac biomarker elevation had a higher rate of all-cause mortality (ΔcTnI: T3: 5.4% vs. T1: 0.5%, p = 0.006; ΔCK-MB: T3: 5.7% vs. T1: 0.9%, p = 0.006) and cardiovascular mortality (ΔcTnI: T3: 4.9% vs. T1: 0.5%, p = 0.01; ΔCK-MB: T3: 3.9% vs. T1: 0.5%, p = 0.02). At 1 year, only patients in the highest CK-MB tertile had higher rates of all-cause (25.4% vs. 16.8%, p = 0.02) and cardiovascular (10.3% vs. 5.0%) mortality. Multivariable analysis demonstrated that greater release of cardiac biomarkers was independently associated with increased mortality in the TF population. After TA-TAVR, being in the highest tertile of cardiac biomarker elevation had no influence on clinical and echocardiographic outcomes at 30 days and 1 year. Conclusions After TF-TAVR, a greater degree of myocardial injury was associated with higher rates of 30-day all-cause and cardiovascular mortality. At 1 year, being in the highest tertile of ΔCK-MB was correlated with a higher rate of all-cause and cardiac mortality. Finally, the level of myocardial injury after TA-TAVR had no impact on clinical and echocardiographic outcomes.
by
Jaffar M. Khan;
Toby Rogers;
William H. Schenke;
Jonathan R. Mazal;
Anthony Z. Faranesh;
Adam B. Greenbaum;
Vasilis Babaliaros;
Marcus Y. Chen;
Robert J. Lederman
OBJECTIVES: The authors propose a novel transcatheter transection of the anterior mitral leaflet to prevent iatrogenic left ventricular outflow tract (LVOT) obstruction during transcatheter mitral valve replacement (TMVR).
BACKGROUND: LVOT obstruction is a life-threatening complication of TMVR caused by septal displacement of the anterior mitral leaflet. METHODS: In vivo procedures in swine were guided by biplane x-ray fluoroscopy and intracardiac echocardiography. Retrograde transaortic 6-F guiding catheters straddled the anterior mitral leaflet. A stiff 0.014-inch guidewire with polymer jacket insulation was electrified and advanced from the LVOT, through the A2 leaflet base, into the left atrium. The wire was snared and externalized, forming a loop that was energized and withdrawn to lacerate the anterior mitral leaflet.
RESULTS: The anterior mitral leaflet was successfully lacerated in 7 live and 1 post-mortem swine under heparinization. Lacerations extended to 89 ± 19% of leaflet length and were located within 0.5 ± 0.4 mm of leaflet centerline. The chordae were preserved and retracted the leaflet halves away from the LVOT. LVOT narrowing after benchtop TMVR was significantly reduced with intentional laceration of the anterior mitral leaflet to prevent LVOT obstruction than without (65 ± 10% vs. 31 ± 18% of pre-implantation diameter, p < 0.01). The technique caused mean blood pressure to fall (from 54 ± 6 mm Hg to 30 ± 4 mm Hg, p < 0.01), but blood pressure remained steady until planned euthanasia. No collateral tissue injury was identified on necropsy.
CONCLUSIONS: Using simple catheter techniques, the anterior mitral valve leaflet was transected. Cautiously applied in patients, this strategy can prevent anterior mitral leaflet displacement and LVOT obstruction caused by TMVR.
by
Adam B. Greenbaum;
Vasilis Babaliaros;
Marcus Y. Chen;
Annette M. Stine;
Toby Rogers;
William W. O'Neill;
Gaetano Paone;
Vinod Thourani;
Kamran I. Muhammad;
Robert A. Leonardi;
Stephen Ramee;
James F. Troendle;
Robert J. Lederman
Background Transcaval access may enable fully percutaneous transcatheter aortic valve replacement (TAVR) without the hazards and discomfort of transthoracic (transapical or transaortic) access. Objectives The authors performed a prospective, independently adjudicated, multicenter, single-arm trial of transcaval access for TAVR in patients who were ineligible for femoral artery access and had high or prohibitive risk of complications from transthoracic access. Methods A total of 100 patients underwent attempted percutaneous transcaval access to the abdominal aorta by electrifying a caval guidewire and advancing it into a pre-positioned aortic snare. After exchanging for a rigid guidewire, conventional TAVR was performed through transcaval introducer sheaths. Transcaval access ports were closed with nitinol cardiac occluders. A core laboratory analyzed pre-discharge and 30-day abdominal computed tomograms. The Society of Thoracic Surgeons predicted risk of mortality was 9.6 ± 6.3%. Results Transcaval access was successful in 99 of 100 patients. Device success (access and closure with a nitinol cardiac occluder without death or emergency surgical rescue) occurred 98 of 99 patients; 1 subject had closure with a covered stent. Inpatient survival was 96%, and 30-day survival was 92%. Second Valve Academic Research Consortium (VARC-2) life-threatening bleeding and modified VARC-2 major vascular complications possibly related to transcaval access were 7% and 13%, respectively. Median length of stay was 4 days (range 2 to 6 days). There were no vascular complications after discharge. Conclusions Transcaval access enabled TAVR in patients who were not good candidates for transthoracic access. Bleeding and vascular complications, using permeable nitinol cardiac occluders to close the access ports, were common but acceptable in this high-risk cohort. Transcaval access should be investigated in patients who are eligible for transthoracic access. Purpose-built closure devices are in development that may simplify the procedure and reduce bleeding. (Transcaval Access for Transcatheter Aortic Valve Replacement in People With No Good Options for Aortic Access; NCT02280824)