Ablation of atrial fibrillation with minimally invasive mitral surgery

With the advent of minimally invasive mitral valve surgery, transeptal exposure of the mitral valve has become increasingly popular. While this approach provides excellent exposure of the mitral valve, it necessitates development of novel strategies for concomitant ablation in patients with atrial fibrillation. We describe a technique for creation of a biatrial lesion set for atrial fibrillation ablation that is easily employed using the transeptal approach to the mitral valve.     

Radiofrequency ablation of atrial fibrillation during mitral valve surgery

Twenty-three patients underwent endocardial radiofrequency ablation of atrial fibrillation (AF) during mitral valve procedures with a previously described left atrial lesion pattern. A temperature-controlled 7-coil surgical probe delivered 60-second lesions at 80 degrees C. The left atrial appendage was oversewn after ablation. Ages ranged from 28 to 88 years. Nineteen patients had chronic AF that was present for over 1 year in 74%; 12 patients had rheumatic mitral stenosis. Mean left atrial diameter was 5.4 +/- 0.7 cm. There was 1 operative death unrelated to the ablation, and no strokes or ablation-related complications were observed. At mean follow-up of 32.5 weeks, 86% of the 22 survivors were in sinus rhythm. All 18 patients with left atrial diameter <6 cm are in sinus rhythm. All postoperative atrial flutter was transient, and no patients required subsequent transcatheter ablation. This lesion pattern is safe and effective when applied in the method described here. It appears to be a reasonable alternative to the complete Maze 3 lesion pattern in patients with mitral valve disease.     

Barriers to atrial fibrillation ablation during mitral valve surgery

BackgroundNearly 40% of patients with atrial fibrillation (AF) undergoing mitral valve surgery do not receive concomitant ablation despite societal guidelines. We assessed barriers to implementation of this evidence-based practice through a survey of cardiac surgeons in 2 statewide quality collaboratives.MethodsAdult cardiac surgeons across 2 statewide collaboratives were surveyed on their knowledge and practice regarding AF ablation. Questions concerning experience, clinical practice, case scenarios, and barriers to implementation were included.ResultsAmong 66 respondents (66 of 135; 48.9%), the majority reported “very comfortable/frequently use” cryoablation (53 of 66; 80.3%) and radiofrequency (55 of 66; 83.3%). Only 12.1% (8/66) were not aware of the recommendations. Approximately one-half of the respondents reported learning AF ablation in fellowship (50.0%; 33 of 66) or attending courses (47.0%; 31 of 66). Responses to clinical scenarios demonstrated wide variability in practice patterns. One-half of the respondents reported no barriers; others cited increased cross-clamp time, excessive patient risk, and arrhythmia incidence as obstacles. Desired interventions included cardiology/electrophysiology support, protocols, pacemaker rate information, and education in the form of site visits, videos and proctors.ConclusionsKnowledge of evidence-based recommendations and practice patterns vary widely. These data identify several barriers to implementation of concomitant AF ablation and suggest specific interventions (mentorship/support, protocols, research, and education) to overcome these barriers.     

Concomitant ablation of atrial fibrillation in rheumatic mitral valve surgery

Objective

Efficacy of atrial fibrillation ablation in rheumatic mitral valve disease has been regarded inferior to that in nonrheumatic diseases. This study aimed to evaluate net clinical benefits by the addition of concomitant atrial fibrillation ablation in rheumatic mitral valve surgery.

Combined atrial fibrillation and mitral valve surgery using microwave technology

Atrial fibrillation is associated with a significant morbidity and mortality and is typically related to patients with mitral valve disease. Microwave ablation is a new option for surgical treatment of chronic atrial fibrillation. We present our experience with surgical treatment of mitral valve disease and microwave ablation in patients with chronic atrial fibrillation. In 105 patients (73 women, 32 men, 68.6 +/- 8 years of age from 45 to 83 years, ejection fraction 28% to 80%, left atrial diameter 56 +/- 9.1 mm from 35 to 97 mm) with mitral valve disease, chronic atrial fibrillation was documented for 8.6 +/- 6.8 years. Microwave ablation was performed using a continuous ablation line starting at the posterior mitral valve annulus and incorporating the interior of all pulmonary veins. In 33 patients, mitral valve reconstruction was performed. Ten patients received biologic valve replacement; 3 of them got a stentless quattro mitral valve prosthesis. Survival rate was 99.1% (n = 104). In the 6-month follow-up, 42 of 69 patients were in sinus rhythm (61%); in the 1-year follow-up, 37 of 64 patients were in sinus rhythm (57.8%). Microwave ablation is a safe and efficient method for surgical treatment of chronic atrial fibrillation in patients with mitral valve disease.     

Combined atrial fibrillation and mitral valve surgery using radiofrequency technology

Recently, intraoperative radiofrequency ablation of the left atrium combined with mitral valve surgery has become widely used. In our center, 30 patients underwent this combined procedure; median sternotomy was used in 16 patients, and port access was used in 14 patients. At hospital discharge, 18 patients (60%) were no longer in atrial fibrillation, and at 6 months, 19 patients (65%) remained in sinus rhythm. All sinus rhythm patients had a well-defined transmitral A wave detectable by echocardiography. One patient sustained a major stroke. Two patients required pacemaker implantation. Such encouraging preliminary results have triggered worldwide interest in the percutaneous and surgical treatment of atrial fibrillation. However, the excellent long-term results with the classic Cox-Maze III operation have not yet been achieved with these newer approaches. Further basic and clinical research is required before a predictable simple and safe technique can be introduced as a new standard for the surgical treatment of atrial fibrillation in patients with or without structural heart disease.     

The significance of atrial fibrillation ablation in patients undergoing mitral valve surgery

Atrial fibrillation is present in close to 50% of all patients undergoing surgery for mitral valve disease.(1-3) However, surgical correction of atrial fibrillation in patients with other cardiac pathology that requires surgical intervention such as mitral valve disease was never considered as a standard approach. The Maze procedure for the treatment of atrial fibrillation was introduced in 1987 and was performed safely in hundreds of patients with excellent outcomes.(4-7) As a result, several centers have begun to combine the Maze procedure with other cardiac procedures, especially mitral valve surgery, without adding undue operative risk to patients.(8) When properly performed, the results with this combined approach have been excellent.(9,10)     

Results of endocardial radiofrequency ablation of atrial fibrillation during mitral valve surgery

AIM: The aim of the study is to evaluate the efficacy of thermocontrolled endocardial radiofrequency (RF) ablation for the patients with mitral valve disorder and associated chronic atrial fibrillation during mitral valve replacement operation. METHODS: Between February 2002 and January 2004, 43 patients with mitral valve disease and associated chronic atrial fibrillation underwent mitral valve replacement and thermocontrolled endocardial RF ablation with Cobra RF system flexible probe at Gulhane Military Academy of Medicine, Department of Cardiovascular Surgery. Eighteen of the patients (41.8%) were males, while the remaining 25 (58.2%) were females. The average age of the patients was 44+/-14.21 (18-66) years. Functional capacity of the patients was class II in 15 (34. 9%), class III in 24 (55.8%), class IV in 4 (9.3%) according to the NYHA classification. At the preoperative period all of the patients were evaluated routinely by twelve-lead ECG, chest film and transthoracic echocardiography (TTE). For the patients over 40 years of age, we performed additional coronary angiography to delineate any coronary lesions. The patients were evaluated at months 1, 3, 6 and annually by twelve-lead ECG, TTE and holter monitoring after discharge. RESULTS: There were not any complications related to the performed technique. No operative and hospital mortality were recorded. At the follow-up period for 35 of 43 patients (81.4%) sinus rhythm was restored. The mean follow-up time was 24.3+/-11.2 (12-35) months. CONCLUSION: Endocardial RF ablation especially during mitral valve surgery is a simple technique to be performed. Early and midterm results of the cohort are satisfying.     

胸腔镜辅助下微创射频消融手术治疗心房颤动临床分析

目的 探讨胸腔镜辅助下微创射频消融手术治疗心房颤动的技术和早期疗效.方法 2006年12月至2007年10月,共有57例心房颤动患者接受了胸腔镜辅助下微创心脏手术,其中男性40例,女性17例,平均年龄56.4岁,术前心房颤动病史(5.7±4.5)年.本组阵发性心房颤动38例,持续性心房颤动7例,长期存在的持续性心房颤动12例;3例患者曾行导管消融治疗,2例已安置永久性起搏器.所有患者均在胸腔镜辅助下实施双侧肺静脉前庭射频消融隔离、心外膜部分去迷走神经化治疗、左心耳切闭(Wolf Mini-maze手术);并在消融前后行心外膜电生理标测.结果 本组患者平均手术时间3.5 h;术中发现左心房血栓1例,1例患者同期行心外膜的心脏同步化手术.无围手术期死亡;1例术后并发急性呼吸功能不全,1例并发急性心功能不全.共16例患者术后及随访期间行胸外直流电复律治疗;全组患者出院时、术后1、3及6个月窦性心律的比例分别为78.9%(45/57)、64.3%(36/56)、83.9%(47/56)和87.0%(20/23);术前阵发性心房颤动患者则为84.2%(32/38)、67.6%(25/37)、86.5%(32/37)和89.5%(17/19).全组随访1～10个月无血栓及栓塞事件发生.结论 胸腔镜辅助微创心脏外科手术主要适用于阵发性心房颤动患者,其早期疗效理想,创伤小,安全性高.     

Development of a high-fidelity minimally invasive mitral valve surgery simulator

Objectives

The aim of this study was to develop a high-fidelity minimally invasive mitral valve surgery (MIMVS) simulator.

Microwave ablation of atrial fibrillation during mitral valve operations

Although the Cox-Maze III procedure cures atrial fibrillation in the majority of patients, it has not had widespread application. Development of new operations that use alternate energy sources and different lesion sets have caused resurgence in the surgical treatment of atrial fibrillation. Microwave creates lines of conduction block by thermal damage and subsequent scar formation. We describe a rapid and simple technique for microwave ablation of atrial fibrillation in patients having mitral valve operations.     

Anesthetic considerations during minimally invasive mitral valve surgery

Advances in instruments and visualization tools as well as circulatory systems for cardiopulmonary bypass during the late 1990s have stimulated widespread adoption of minimally invasive mitral valve surgery (MIMVS). Today, MIMVS is the standard approach for many surgeons and institutions. There are multiple benefits of MIMVS. Patient satisfaction and improved cosmesis are important. Additionally, studies have consistently shown faster recovery times and less associated pain with MIMVS. Statistically significant improvement in bleeding, transfusion, incidence of atrial fibrillation, and time to resumption of normal activities with MIMVS has also been shown when comparing MIMVS with conventional mitral surgery. Most important, these benefits have been achieved without sacrificing perioperative safety or durability of surgical repair. Although a steep learning curve still exists given the high level of case complexity, continued development fueled by increasing patient demand may allow for even further expansion in the use of minimal invasive techniques.     

Reexamining contraindications for minimally invasive mitral valve surgery

Historically, contraindications to minimally invasive or robotic mitral valve surgery have included prior mastectomy, thoracic reconstruction, or chest radiation. However, we believe that by granting flexibility in the choice of skin incision site while performing careful dissection, surgeons can provide these patients the outstanding results afforded by a minithoracotomy. We present a patient who had undergone a prior mastectomy and radiation treatment in whom we performed a minimally invasive mitral valve repair through a right-sided minithoracotomy using the previous mastectomy incision.     

Robotic-assisted instruments enhance minimally invasive mitral valve surgery

BACKGROUND: The potential for totally endoscopic mitral valve surgery has been advanced by the development of minimally invasive techniques. Recently surgical robots have offered instrument access through small ports, obviating the need for a significant thoracotomy. This study tested the hypothesis that a microsurgical robot with 5 degrees of freedom is capable of performing an endoscopic mitral valve replacement (MVR). METHODS: Dogs (n = 6) were placed on peripheral cardiopulmonary bypass; aortic occlusion was achieved with endoaortic clamping and transesophageal echocardiographic control. A small left seventh interspace "service entrance" incision was used to insert sutures, retractor blade, and valve prosthesis. Robotically controlled instruments included a thoracoscope and 5-mm needle holders. MVR was performed using an interrupted suture technique. RESULTS: Excellent visualization was achieved with the thoracoscope. Instrument setup required 25.8 minutes (range 12 to 37); valve replacement required 69.3+/-5.39 minutes (range 48 to 78). MVR was accomplished with normal prosthetic valve function and without misplaced sutures or inadvertent injuries. CONCLUSIONS: This study demonstrates the feasibility of adjunctive use of robotic instrumentation for minimally invasive MVR. Clinical trials are indicated.     

Ischemic cardiomyopathy with mitral valve regurgitation and atrial fibrillation; report of a case

A 45-year-old man suffering from severe heart failure due to mitral regurgitation and atrial fibrillation was admitted to our hospital. He underwent intracoronary thrombolysis for left anterior descending artery 10 years ago and stent insertion for right coronary artery 3 years ago. We performed mitral annuloplasty using a Carpentier-Edwards Physio ring 28mm and modified maze procedure. The modified maze procedure consists of right sided left atriotomy extended to the left margin of the left pulmonary vein orifices and cryoablation applied to the remnant of the left atrial wall between the left upper and lower pulmonary vein orifice and cryoablation applied to the right atrial isthmus. These procedures could be effective for endstage heart failure.     

How I do it: self-retaining atrial retractors for robotic and minimally invasive mitral valve surgery

Successful surgery, particularly on the heart valves, is dependent on excellent and consistent exposure of the operative field. In this report, we describe 2 types of new atrial retractors designed for robotic and minimally invasive mitral valve surgery. These simple and easy-to-handle atrial retractors provide exceptional and consistent exposure of the left atrium in robotic and minimally invasive mitral valve surgery and prevent traumatic injury.