1、Microwave Ablation For Chronic Atrial Fibrillation,Li Poa, M.D., F.A.C.S. Director of Perioperative Services Enloe Medical Center Chico, California,The Future of Cardiac Intervention (National Health Council),Stent and intravascular intervention expected to double over next 3 years CABG volume to de
2、cline about 10% with cardiac surgery primarily expanding in EPS and CHF such as ablative surgery, biventricular pacing, LV remodeling, and cardiac muscle augmentation. Valvular volume to increase about 20% by 2005,Chronic Atrial Fibrillation,Affects 2 million people in the US alone with a 9% 5 year
3、morbidity from anticoagulation and a 5% / year risk of stroke As high as an 80 % risk of stroke at 8 years in the Japanese study group (Kitamura) Available treatment modalities include surgical “Maze”, cryotherapy, radiofrequency, irrigating radiofrequency, microwave, and laser Surgical Maze success
4、 best overall but Microwave has the least complications and the best ease of use,Microwave Ablation: 3000 patients,Open Heart2300 patients 75% success - 0 to 4 year follow up,Beating Heart Off-Pump 700 patients 80% success - 0 to 2 year follow up,No adverse events,MIS Off-PumpMini Thoracotomy 3 case
5、s Robotic 2 cases Thoracoscopy 2 cases,2 cm - FLEX 2TM,4 cm - FLEX 4TM,7 cm - FLEX 7,“.specimens were characterized by myocellular damage involving the full thickness of the atrial wall, where thickness ranged from 4 - 5 mm to 1 cm.”,Clinical Histopathology and Ultrastructural Analysis of Myocardium
6、 following Microwave Energy AblationEric Manasse MD, Piergiuseppe Colombo MD, Paola Braidotti PhD,Massimo Roncalli MD-PhD, Roberto Gallotti MD,(submitted to the Annals of Th. Surg.),from: In Vitro and In Vivo Evaluation of the Thermal Patterns and Lesions of Catheter Ablation with a Microwave Monopo
7、le AntennaDavid Keane MD, Ph.D., Jeremy Ruskin MD, Nancy Norris, Pierre-Antoine Chapelon, Dany Berube, Ph.D.,Beating-Heart Surgery,Epicardial ablation Endocardial view,Transmural Lesion,Viable Tissue,Beating-Heart Surgery,Dr. Maessen - Maastricht, Netherlands (Off-pump),40 patients (32 cAF, 8 pAF)ac
8、ute discharge FU 40/40 26/39 32/39 (82%)10 patients 8 - 11 months 10 patients 6 - 8 months19 patients 0 - 6 months,Presented at ISMICS - 2002,n = 31 (mitral valve)26/31 (84%) in sinus rhythm,Dr. Zembala - Zabrze, Poland (Arrested Heart),Presented at CTT - 2002,29 patients (concomitant surgeries) 14
9、MV - 15 CABG 92% in NSR Follow-up:8 patients more than 6 months21 patients between 1 and 5 months,submitted to the Annals of Th. Surg. - 2002,Prof. Schutz - Munich, Germany (Arrested Heart),14 patients (beating-heart and arrested-heart) 79% in NSR (11/14) 64% without AA drugFollow-up:mean 131 days (
10、63 - 331 days),Prof. Gallotti / Dr. Manasse - Milan, Italy (Arrested Heart),Presented at CTT - 2002,12 patients (on-pump, concomitant surgeries) 75% in NSRFollow-up:up to 3 months,Dr. Gillinov - Cleveland Clinic (Arrested Heart),Dresden Experience,211 consecutive patients with documented atrial fibr
11、illation for average of 6.8 years concomitant MVR, CABG, AVR, and TVR,Survival 98%, no MW complications 70% NSR at 6 months 68% NSR at 1 year with normal atrial transport function 23% had a postop PPM implant,The International Medical Group Conference “How to Treat Atrial Fibrillation During Mitral
12、Valve Surgery”, Anno Diegeler, 21 July 2001,The Dresden experience - Dr. Michael Knaut (Arrested Heart),Patient Population: n = 120At least 6 months of documented chronic AFRefractory to at least 2 AA drugs1 Year Results: 70-75% in sinus rhythm (n = 60)Sub-PopulationsBypass: 60% in sinus rhythmMitra
13、l replacement: 70% in sinus rhythmMitral repair: 71% in sinus rhythmTricuspid: 75% in sinus rhythmAortic: 85% in sinus rhythm,Comparative study on Concomitant Atrial Fibrillation,Group A - 62 patients with no ablation during surgery survival 94.2% NSR in 6% of MVD; 9% with CAD; and 5% with AVD disea
14、se processes,Group B - 88 patients receiving MW ablation with their surgery survival 98% NSR in 62% of MVD; 70% with CAD; and 82% with AVD disease processes,Knaut, M; et al Dresden, Germany,10- 15 patients per subgroup Microwave = 91% (11/12 NSR)Radiofrequency = 65%Cryoablation = 55% 7 to 12 month f
15、ollow-up,Presented at EACTS - 2001,Dr. Graffigna - Trento, Italy (Arrested Heart),Dr. Kshettry & Dr. Saltman Minneapolis & Stony Brook (Off-pump),21 cAF patients (all Mitral Valve),Submitted STS - 2003,Acute13 (62%) NSR5 (24%) paced rhythm1 ( 7%) JCT rhythm2 (10%) AF,Follow-up (1 - 3 months) (n = 20
16、)17 (85%) NSR3 (15%) AF,Dr. David Kress and Dr. Murali Dharan,20 patients (18 epicardial, 2 endocardial) 100% left OR in sinus or paced rhythm 75% free of AF at discharge 73% of chronic pts free of AF at 3 months (11/15) 80% pf paroxysmal pts free of AF at 3 months (4/5)No perioperative complication
17、s, deaths, or collateral damage,Presented at NASPE, May 2002,Presented at NASPE, May 2002,Dr. Tom Molloy Portland, OR,19 patients (9 off-pump, 10 on-pump) 100% left OR in sinus or paced rhythm 62% free of AF at discharge 89% of pts free of AF at last follow-up (17/19) Only 37% (7/19) are still on an
18、ti-arrhymthic drug,Presented at New Era, January 2003,Dr. Donald Thomas Chicago, IL,22 patients (11 off-pump, 11 on-pump) 100% left OR in sinus or paced rhythm 86% of pts (19/22) free of AF at last follow-up,Submitted to ISMICS, 2003,Cardiology EP Experience,Primary foci appear to be at endovascular
19、 muscular sheaths at vascular insertion points initial attempts at primary ablation within pulmonary veins led to pulmonary vein stenosis,Present EP technique involves encircling pulmonary vein orifices ablating on endocardial surface of atrium but presently takes an average of 5-6 hours in expert h
20、ands using catheter based approach.,RSPV,RIPV,LAA,MV,LSPV,LIPV,Endocardial Left Atrial Ablation,RAA,TV,Endocardial Right Atrial Ablation,CS,IVC,SVC,Septotomy,Initial cardiomyoplasty trials from Singapore and French groups now have 15-23% 10 year survival rates larger population now considered in reo
21、pened trials given that atrial fibrillation was an initial contraindication in the first groups with concurrent atrial ablative surgery synchrony is achievable,Cardiomyopathy Support,Enloe Experience,Concomitant cardiac surgery in patient with chronic (3 months) atrial fibrillation or recurrent paro
22、xysmal atrial fibrillation Failure of AA drug preop Isthmus ablation when R atrial approach,37 left atrial ablations 21 epicardial, 16 endocardial6 right sided ablations Success rates 87 % success in endocardial 85 % success in epicardial,PreAblation Issues,Ensure atrium is free of clot especially w
23、hen contemplating epicardial ablation If performing concomitant “off-pump” CABG, recommend performing lateral wall distal anastomoses prior to ablation Ensure complete, detailed identification of pulmonary vein anatomy looking for all possible aberrancies,Technical Considerations,Ensure adequacy of
24、ablation, take the time to make crossing lesions Try to keep ablation surfaces relatively dry Endocardial ablation: Ensure 1) blood flow through coronaries and 2) TEE probe pulled back. Epicardial ablation : Ensure avoidance of coronary arteries, coronary sinus, and pulmonary artery Remember that At
25、rial Natriuretic Peptide production occurs in the atrial appendages and full ligation/removal can cause transient renal insufficiency,Postoperative management,Continue patient on antiarrhythmic medication for 2-3 months, use aggressive cardioversion protocol for atrial fibrillation Continue patient
26、on anticoagulation therapy for 2-3 months May need temporary cardiac stimulation for initial 48-72 hour period of atrial stunning so definitely have atrial pacing capability,Microwave Ablation Experience,3000 cases performed worldwide with no adverse effects 700 epicardial cases thus far and 7 by minimally invasive approaches Success rates are approximately 100% upon leaving the OR with 1/3 going back into atrial fibrillation upon discharge but then range from 74 - 92% successful conversion and retention of NSR at 6 months postoperatively,
