MAIN TOPIC REVIEWS Dong Seop Jeong, MD, PhD Department of Thoracic and Cardiovascular Surgery, Cardiovascular Imaging Center, Samsung Medical Center, Sungkyunkwan University School of Medicine Received: November 3, 2014 Revision Received: February 27, 2015 Accepted: March 26, 2015 Correspondence: Dong Seop Jeong, MD, PhD, Department of Thoracic and Cardiovascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul 135-710, Korea Tel: + 82-2-3410-3488, Fax: +82-2-3410-0089 E-mail: opheart1@gmail.com Copyright 2015 The Official Journal of Korean Heart Rhythm Society Editorial Board & MMK Co., Ltd. ABSTRACT Atrial fibrillation (AF) is present in 1% to 2% of the general population, and its prevalence has been predicted to increase more than five-fold within the next 40 years. Patients with AF are at least five times more likely to have a stroke than patients without AF. Approximately 90% of all strokes are ischemic, and 15% to 20% of all ischemic strokes are associated with AF. More than 90% thrombi are located at the left atrial appendage (LAA) in patients with AF. Since the recent development of potentially safer and more effective percutaneous devices and minimally invasive surgical techniques for closing the LAA, interest has been renewed in the potential for using these mechanical approaches to decrease the incidence of stroke in patients with AF. This review summarizes the current status regarding surgical approaches to LAA exclusion. Key Words: atrial fibrillation, left atrial appendage, stroke 서론 메이즈술식에동반된좌심방이차단술 만성심방세동을치료하는수술적방법은메이즈 (maze) 술식이대표적이다. 메이즈술식은심방세동의유발부위를전기적으로차단하고, 심방내존재하는거대재진입로를예방적으로차단함과동시에좌심방이를절제함으로써재발후에도혈전으로인한뇌졸중의유병률을낮춘다. 1,2 하지만매우침습적이어서단독심방세동환자들에서는거의시행되고있지않다. 최근에는흉강경을이용한메이즈술식이개발되어좌심방이의수술적절제가비교적비침습적으로가능하게되었다. 흉강경을이용한수술적절제방법은여러가지가시도되고있으며, 그결과들이주목받고있다. 3,4 개흉하여메이즈술식을하는경우좌심방이를쉽게차단혹은제거할수있다. 그방법은아래와같다. Internal obliteration Epicardial ligation Resection and closure Stapling exclusion Left atrial clipping 이중가장많이사용되는전통적인방법은좌심방이입구를내부에서봉합하여막는방법이다. 하지만최근에는좌심방이의내부와좌심방사이가개통되는경우가종종보고되고있어그안정성에의문점이제기되고있다. 5 좌심방이제거술과차단술중에서는차단술보다는제거술이 48
Table 1. Success of different techniques for left atrial appendage (LAA) closure Type Number Patent LAA Remnant LAA Persistent flow Success Excision, n (%) 52 0 14 (27) 0 38 (73) Suture exclusion, n (%) 73 6 (8) 6 (8) 44 (61) 17 (23) Stapler exclusion, n (%) 12 2 (17) 7 (58) 3 (25) 0 Total, n (%) 137 8 (6) 27 (20) 47 (34) 55 (40) 성공률이높고안전하다는쪽이우세한실정이다 (Table 1). 6 흉강경하부정맥수술과좌심방이제거술 경피적전극도자절제술이약물요법에비해월등히정상리듬유지율이높은것으로알려졌으나, 여전히환자의 1/3 에서는재발을경험하고있을뿐아니라재발에의한뇌졸중발생위험으로뇌졸중예방을위한항응고제를끊지못하는환자들이매우많다. 반면수술적요법은그침습성으로인해한계가있어거의시행되지못하는실정이다. 이에위험하지않으면서 ( 최소침습 ) 정상리듬유지율이높으며, 재발하더라도좌심방이입구를막거나차단하여뇌졸중을예방할수있는치료법이절실해졌고, 흉강경하부정맥수술이그역할을시작하게되었다. 양쪽겨드랑이아래에 3개씩 5 mm의포트를뚫어중앙은흉강경카메라, 나머지 2개는흉강경수술도구및양극성고주파절제기구를위해사용한다. 흉강경하부정맥수술은아래와같은술식으로구성되어있다. Pulmonary vein isolation ( 폐정맥주위차단 ): 심방세동의주된원인차단 Ganglionated plexi ablation ( 신경절차단 ): 재발의원인이되는부분제거 Resection of left atrial auricle ( 좌심방이제거 ): 혈전이가장흔한장소제거 Posterior and superior line ablation ( 추가차단술 ): 장기성적향상도모 Division of ligament of Marshall ( 마샬밴드절제 ): 심방세동재발의드문원인이됨 이중좌심방이제거는심방세동에서혈전의 90% 가발생하는부위인좌심방이 (left atrial appendage) 를외과적으로절제하고, 수술장내에서경식도심초음파를이용하여잔존좌심방이의여부를확인하게된다. 좌심방이를제거하기위해서는 Figure 1과같이흉강경수술용자동봉합기 (stapler) 를사용하거나좌심방이클립적용혹은수술적봉합등의방법을사용한다. 6 그중가장많이사용되는방법은자동봉합기를사용하는방법이다. 좌심방이를외과적으로제거하여혈전발생은물론전기적으로도재발을예방할수있다는장점이있기때문이다. 클립을사용하는경우는좌심방이의입구는막을수있으나자체를제거하는것이아니기때문에장기적으로재개통될위험이있고, 전기적차단효과가증명되어있지않아추적결과가필요하다. 수술적봉합은술식이어려워출혈, 좌심방이파열등의치명적합병증이발생할수있다는단점이있다. 최근경향 최근에는좌심방이차단용클립이발전하여좌심방이의크기에따라맞춤형클립이고안되었을뿐만아니라차단시잔존좌심방이가남지않도록좌심방이클립용수술도구가진화하여점점더많은관심을받고있다 (Figure 2). 장기개통을방지하기위해지속적인압박이가해지는재질을사용하여장기성적이주목된다. Emmert 등에의하면가장최근의결과는매우고무적이다. 7 모든환자들에서잔존좌심방이는없었고, 재개통도없었으며, 미끄러진증례도없었다. 하지만 3년의결과이기때문에임상적으로안심하고사용하기위해장기간연구가필수적이라고생각한다. 49
Figure 1. Thoracoscopic resection of left atrial appendage: Left atrial auricle can be safely removed using 60 mm length stapling device after pericardial open. Figure 2. Before and after resection of left atrial auricle: bioglue was applied to stop residual bleeding. 50
AtriClip PRO Quick deploy feature Head articulation 60 side-to-side and up / down w/lock feature Rigid shaft AtriClip long Head articulation 180 side-to-side Thumb control Malleable shaft (25 mm) AtriClip standard Head articulation Plunger grip Stiff shaft (6 mm) Figure 3. Clip for left atrial appendage closure. 51
결론 수술적좌심방이절제혹은차단술은가장확실한방법이긴하지만침습적이기때문에관심을받지못하였다. 최근흉강경하부정맥수술이도입되면서좌심방이제거가안전하고도비침습적으로시행되기시작하였다. 자동봉합기혹은클립을이용한최소침습좌심방이제거및차단술은아직장기결과가필요하지만단독심방세동환자들에서뇌졸중을예방하는또하나의대표적인옵션으로서자리매김할것으로기대한다. References 1) Prasad SM, Maniar HS, Camillo CJ, Schuessler RB, Boineau JP, Sundt TM 3rd, Cox JL, Damiano RJ Jr. The Cox maze III procedure for atrial fibrillation: long-term efficacy in patients undergoing lone versus concomitant procedures. J Thorac Cardiovasc Surg. 2003;126:1822-1828. 2) Raanani E, Albage A, David TE, Yau TM, Armstrong S. The efficacy of the Cox/maze procedure combined with mitral valve surgery: a matched control study. Eur J Cardiothorac Surg. 2001;19:438-442. 3) Piston L, La Meir M, van Opstal J, Blaauw Y, Maessen J, Crijns HJ. Hybrid thoracoscopic surgical and transvenous catheter ablation of atrial fibrillation. J Am Coll Cardiol. 2012;60:54-61. 4) Muneretto C, Bisieri G, Bontempi L, Cumis A. Durable staged hybrid ablation with thoracoscopic and percutaneous approach for treatment of long-term atrial fibrillation: A 30-month assessment with continuous monitoring. J Thorac Cardiovasc Surg. 2012;144:1460-1465. 5) Schneider B, Stollberger C, Sievers HH. Surgical closure of the left atrial appendage - a beneficial procedure? Cardiology. 2005;104:127-132. 6) Lee HM, Chung SR, Jeong DS. Initial experience with total thoracoscopic ablation. Korean J Thorac Cardiovasc Surg. 2014;47:1-5. 7) Emmert M, Puippe G, Baumuller S, Alkadhi H, Landmesser U, Plass A, Bettex D, Scherman J, Grunenfelder J, Genoni M, Falk V, Salzerg S. Safe, effective and durable epicardial left atrial appendage clip occlusion in patients with atrial fibrillation undergoing cardiac surgery: first long-term results a prospective device trial. Eur J Cardiothorac Surg. 2014;45:126-131. 52