A factor of success for either replacement or repair of

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1 Extended Vertical Transatrial Septa1 Approach to the Mitral Valve Gerard M. Guiraudon, MD, John G. Ofiesh, MD, and Raj Kaushik, MD Division of Cardiovascular and Thoracic Surgery, Department of Surgery, University Hospital, University of Western Ontario, London, Ontario, Canada Optimal mitral valve operation requires adequate exposure without impairment of atrial physiology, namely sinus node and atrioventricular node function. We used an extended vertical transseptal atrial approach in 34 consecutive patients. The extended vertical transseptal approach combines two semicircular atrial incisions circumscribing the tricuspid and mitral annuli anteriorly and superiorly, allowing exposure of the mitral valve by deflecting the ventricular side using stay sutures. The right atrium is opened anteriorly along the atrioventricular sulcus. The atrial septum is incised vertically through the fossa ovalis. The right atriotomy is extended superiorly in the right coronary fossa between the right atrial appendage and the atrioventricular sulcus to meet the septal incision. The two joint incisions are extended onto the left atrial roof transversely. At this point, the two semicircular incisions are performed and joined, and mitral valve operation is performed. There were 18 women and 16 men. Five patients had ischemic mitral valve regurgitation, 18 had mitral valve prolapse, and 11 had rheumatic heart disease. The mitral valve was replaced in 17 patients and repaired in 17. There were no perioperative complications associated with the atriotomies, ie, no bleeding, no atrioventricular nodal dysfunction, and no sinus node dysfunction. The extended vertical transatrial septal approach provides good mitral valve exposure without inherent complications. (Ann Tkorac Surg 1991;52: ) dequate exposure of the mitral valve is a critical A factor of success for either replacement or repair of the mitral valve apparatus. The currently preferred approach is a left atrial incision within the right interatrial sulcus through a median sternotomy [l]. Variant approaches have been advocated to deal with complex cases, with special concern for a small left atrium or reoperations [2-71. We have designed an approach to the mitral valve: the extended vertical transatrial septal approach. This approach was designed to include the following features: (1) routine use through a medial sternotomy; (2) absence of distortion of the mitral valve apparatus; (3) no impairment of atrial functional anatomy, namely, sinus node and atrioventricular node function; and (4) no inherent complications. Material and Methods Pa tien t Population Since December 1986, 34 consecutive patients had mitral valve operation using the extended vertical transseptal atrial approach. There were 18 women and 16 men. Their ages ranged from 26 to 79 years. Twenty-eight patients had mitral valve regurgitation, which was associated with ischemic heart disease in 5, Presented at the Twentyseventh Annual Meeting of The Society of Thoracic Surgeons, San Francisco, CA, Feb 18-20, Address reprint requests to Dr Guiraudon, University Hospital, 339 Windermere Rd, London, Ont N6A 5A5, Canada. mitral valve prolapse in 18, and rheumatic heart disease in 5. Six patients had rheumatic mitral valve stenosis. Twelve patients had associated serious coronary artery disease, including the 5 patients with ischemic mitral valve regurgitation. Twenty-four patients had a dilated left atrium on preoperative echocardiographic study (left atrial diameter greater than 40 mm), whereas 10 had normal left atrial dimension. The average left atrial diameter was mm (standard deviation) (range, 24 to 90 mm). Twelve patients were in sinus rhythm preoperatively, whereas 20 were in permanent atrial fibrillation. Two patients had a permanent pacemaker implanted. Surgical Technique The heart was exposed through a median sternotomy in all patients. Cardiopulmonary bypass was attached to the patient using conventional aortic cannulation and double venous cannulation. The venous cannulas were introduced into the posterior segment of the lateral right atrial wall. Hypothermic cardiopulmonary bypass was started with rectal temperature lowered to 28 C. Tapes were snared around inferior and superior venae cavae. The right atrium was opened longitudinally along the anterior segment of the atrioventricular fat pad (Fig 1). A pursestring suture was attached around the coronary sinus orifice. The aorta was cross-clamped, and cold blood cardioplegic solution was infused into the coronary sinus using a 16F Foley catheter [8]. The extended vertical transseptal approach to the mitral valve was completed as by The Society of Thoracic Surgeons /91/$3.50

2 1991;52: GUIRAUDON ET AL 1059 A B Fig I. (A) Schematic operative zliew and (B) operative view of atrial incisions. The sernicircrltnfereritinl right atriototny is roidely opened to shozo the vertical septal incision extended into the left atrium. (A0 = aorta; CS = coronary sinus; IVC = inferior uena cam; LA = left atrium; PA = pulmonary artery; RA = right atrium; RV = right ventricle; SVC = superior vena cam; TV = tricuspid valoe.) follows. The atrial septum was incised vertically through the fossa ovale. The atrial septal incision terminated inferiorly at the inferior pole of the fossa; it was prolonged superiorly by 1 to 2 cm into the atrial septum. The right atriotomy was prolonged superiorly into the right coronary fossa between the right atrial appendage and the atrioventricular sulcus to join the superior end of the septal incision. From where the two incisions met, the roof of the left atrium was incised. The left atriotomy was extended to the left over 3 to 5 cm, at a distance from the aortic root. After completion of the atriotomies, two joint semicircular incisions were made circumscribing, at a distance, the tricuspid orifice anteriorly and superiorly and the mitral valve orifice anteriorly (septal incision) and superiorly. The exposure of the mitral valve apparatus was completed by deflecting the "ventricular" edge of the septal incision using stay sutures secured over the left A B Fig 2. Similar views as depicted in Figure 1. The septal incision is deflected by stay sutures to expose the tnifral valve. (MV = niitral valve; other abbreviations as in Figure 1,)

3 1060 GUIRAUDON ET AL 199 1;52: side of the sternotomy (Fig 2). A retractor was used for additional exposure. The mitral valve was readily exposed without dislocation or distortion. Pathology and functional anatomy of the mitral valve were assessed, and operation on the valve could proceed using either repair or replacement. Concurrent cardiac operation was carried out before or after mitral valve operation according to the surgeon s choice. Atriotomies were closed using 3-0 monofilament running sutures. The superior left atrial incision was closed, then the septal incision starting at the lower end upward. The two sutures were tied where they met together, and the right atrial incision was closed. The vascular clamp occluding the aorta was then removed. Results The mitral valve was replaced in 17 patients and repaired in 17 [9, 101. Five patients died within 1 month postoperatively: 3 of low output failure and 2 of cerebrovascular accident. Mean aortic cross-clamping time was 45 minutes for isolated mitral valve procedures and 60 minutes when concomitant procedures were carried out. There were no complications associated with closure of atriotomy; in particular, there was no retroaortic left atrial bleeding and no atrial septal defect. All 12 patients in sinus rhythm preoperatively remained in sinus rhythm postoperatively. There was no heart block postoperatively. Comment Exposure of the mitral valve apparatus has been satisfactory without the need for forceful retraction. In most cases only stay sutures were used. It was believed that mitral valve operation was made easier and shorter. Aortic cross-clamping time for mitral valve repair was 45 minutes, and there was no short-term or long-term relapse of mitral valve regurgitation. Repair of atriotomy was not associated with bleeding or postoperative dehiscence such as an atrial septal defect. The septal segment was repaired by closing the edge of the fossa ovale, not the thin, friable membrane. There was no atrioventricular nodal dysfunction. This is consistent with the topography of the incisions, which are kept away from the atrioventricular nodal area. Conversely, the preservation of the sinus node function is more striking. The sinus node artery can be severed either by the right atriotomy in the right coronary fossa or by the left atrial incision [ll]. However, blood supply through the sinus node artery does not seem necessary to sustain normal sinus node function, as suggested by experimental sinus node isolation [12], cardiac transplantation in which the recipient heart stays in sinus rhythm [13], dissection of the right coronary fossa for Wolff-Parkinson-White syndrome [14], and the superior approach to the mitral valve [6]. Recently, we have modified the technique to spare the sinus node artery arising from the right coronary artery using similar dissection as the epicardial approach to the anterior septal pathway. The fat pad in the right coronary fossa is partially mobilized to allow the right atriotomy to be carried out closer to the tricuspid annulus without involving the sinus node artery. In conclusion, we have reported an approach to the mitral valve that is associated with adequate exposure and no inherent complications. Many approaches to the mitral valve have been described. Recently, Balasundaram and Duran [l] have reviewed the subject. They stated that their preferred approach is still the vertical left atriotomy through the interatrial groove exposed using a median sternotomy, although in selected cases, they transect the superior vena cava for adequate exposure [7]. We have used the extended vertical transseptal atrial approach routinely because it provided excellent exposure in every case, whatever the size and morphology of the heart. Supported by the Heart and Stroke Foundation of Ontario. References 1. Balasundaram SG, Duran C. Surgical approaches to the mitral valve. J Cardiac Surg 1990;5: Clowes GHA, Neville WE, Sancetta SM, et al. Results of open surgical correction of mitral valvular insufficiency and description of technique for approach from left side. Surgery 1962;51: 13& Effler DB, Groves LK, Martinez WV, Kolff WJ. Open-heart surgery for mitral insufficiency. J Thorac Surg 1958;36: Dubots C, Guilmet D, de Parades B, Pedeferri G. Nouvelle technique d ouverture de I oreillette gauche en chirurgie a coeur ouvert: l abord di-auriculaire transseptal. Presse Med 1966;74: Saksena DS, Tucker BL, Lindesmith GG, Nelson RM, Stiles QR, Meyer BW. The superior approach to the mitral valve. A review of clinical experience. 1971;12: 14& Hirt SW, Frimpong-Boateng K, Borst HG. The superior approach to the mitral valve-is it worthwhile? Eur J Cardiothorac Surg 1988;2: Selle JG. Temporary division of the superior vena cava for exceptional mitral valve exposure. J Thorac Cardiovasc Surg 1984;88: Guiraudon GM, Campbell CS, McLellan DG, et al. Retrograde coronary sinus versus aortic root perfusion with cold cardioplegia. Randomized study of levels of cardiac enzymes in 40 patients. Circulation 1986;73(Suppl 3): Rankin JS, Feneley MP, Hickey MSt.J, et al. A clinical comparison of mitral valve repair versus valve replacement in ischemic mitral regurgitation. J Thorac Cardiovasc Surg 1988;95: Carpentier A. Cardiac valve surgery-the French correction. J Thorac Cardiovasc Surg 1983;86:32> McAlpine WA. The arteries to the atria and to the A.V. node. In: Heart and coronary arteries. New York: Springer-Verlag, 1975: Sealy WC, Bache RJ, Seaber AV, Bhattacharga SK. The atrial pacemaking site after surgical exclusion of the sinoatrial node. J Thorac Cardiovasc Surg 1973;65: Ellenbogen KA, Arrowood JA, Cohen MD, Szentpetery S. Limitations of esophageal electrocardiography in recording atrial rhythms after orthotopic heart transplantation. J Heart Transplant 1987;6: Guiraudon GM, Klein GJ, Sharma AD, Yee R, Pineda EA, McLellan DG. Surgical approach to anterior septal accessory pathways in 20 patients with the Wolff-Parkinson-White syndrome. Eur J Cardiothorac Surg 1988;2:201-6.

4 1991 :52: 105M2 GUIRAUDON ET AL 1061 DISCUSSION DR DELOS M. COSGROVE 111 (Cleveland, OH): Dr Guiraudon, what is the main impetus for doing this? Is it a problem with exposure through the standard left atrial approach? DR GUIRAUDON: The main incentive was the shortage of residents and, of course, the need for adequate exposure. Expert assistants are required to handle a Cooley retractor, whereas the extended transatrial approach avoids the need for expert assistance. DR TIRONE DAVID (Toronto, Ont, Canada): Why not use a self-retaining retractor? There are all kinds of self-retaining retractors available to replace the resident holding a Cooley s retractor. My main concern with your incision is the sinoatrial node artery. I am surprised that 12 patients had normal sinoatrial nodes after the operation. I have limited experience in dividing the sinoatrial node artery, but I have a number of patients in whom sick sinus syndrome developed. I occasionally struggle to see the mitral valve to repair it, but all we do then is transect the superior vena cava a centimeter above the sinoatrial node and then carry the atriotomy toward the roof of the left atrium similar to the way you described. This approach gives excellent exposure. DR GUIRAUDON: I have shared Dr David s concerns but had to admit, based on convincing evidence, that normal sinus node function is preserved after suppression of sinus node artery flow. Dr W. C. Sealy has reported normal function after total isolation of the sinus node. There is no report of sinus node dysfunction associated with the left superior approach to the mitral valve, although the sinus node artery should be divided in 25% to 30% of patients. I am aware of at least 300 patients who were operated on using the technique I just presented without associated sinus node dysfunction. DR DAVID: Doesn t the sinoatrial node need blood supply? DR GUIRAUDON: Atrial myocardial blood supply is complemented by substantial noncoronary flow, as well evidenced by the absence of atrial necrosis after heart transplantation, which abolishes coronary flow. The sinus node may exhibit normal function after heart transplantation. Atrial ischemia is a rare condition with few atrial acute infarctions reported. I agree that the division of the superior vena cava provides an excellent exposure when combined with the classic left atrial incision. This approach is advocated by Selle, C. Duran, and many others. The extended vertical transseptal approach seems to provide identical excellent exposure with no inherent complications and without the need for vena cava repair. DR ROBERT W. M. FRATER (Bronx, NY): I agree completely with Dr Guiraudon that this is a superb approach to the mitral valve. For about 600 or 700 cases I have used the transseptal approach from the right side of the coronary sinus back into the right superior pulmonary vein. That always leaves a bit of a ridge superiorly. Having seen at the Video Surgery Conference in Italy last September the alternative of making a vertical septa1 approach into the left atrial dome, I tried it immediately. 1 found it the best exposure of the mitral valve without the need f u more than couple of retraction sutures to create the exposure, and it has the same level of preservation, in the short term, of sinus function as I achieved with the older transseptal approach. I recommend all of you try it, extending a vertical transseptal incision to the right side of the coronary sinus so you do not get the conducting system, up between the vena cava and aorta into the dome; you will be astonished at the level of exposure. It is easy to do, it is easy to close, and it is truly without complications thus far in my experience. With Dr Guiraudon s presentation today, there are now at least four surgeons who are using it. It is clearly an idea that has suddenly hit everybody at the same time, and I think it is an idea that is on its way. DR FREDDY VERMEULEN (Nieuwegein, the Netherlands): I support Dr Guiraudon with his approach; I learned it from him. We recently reviewed our 300 last mitral or mitral and tricuspid valve operations; in this group we used this approach at the surgeon s preference in about 100 cases. As one of the six surgeons of our group I really can support all of Dr Guiraudon s findings: no major bleeding, no rhythm disturbances, and no change thus far in patients previously in sinus rhythm. The major advantage is the excellent exposure: I noted that our resident in training-and we have a different training program than in the States, as residents start very early in cardiothoracic surgery-really can watch how we do mitral valve operation; especially in mitral valve reconstruction it is a major advantage. At present, most of my associates are using this approach almost routinely. There has been another paper presented at the last meeting of the European Association for Cardiothoracic Surgery by Dr Alfieri of Brescia, who reviewed his experience; he also learned this approach from Dr Guiraudon, and he supports all of the findings of those that have used it and as shown to us today by Dr Guiraudon. DR CIRO CAMPANELLA (Edinburgh, Scotland): Did you explore, before embarking on your technique, the possibility of solving the problem of a poor approach by extending the standard longitudinal incision for routine mitral valve with a second one perpendicular to it like an inverted T? With this method, after assessing the mitral valve exposure using the standard longitudinal incision in front of the right superior pulmonary vein, if you believe the approach is inadequate you can choose to snare the cava and open perpendicularly the right atrium, the interatrial sulcus, and the interatrial septum. The exposure now is like in a book. Also, how long a cross-clamping time did your technique add to the overall length of the procedure? DR GUIRAUDON: The average cross-clamping time was 45 minutes for mitral valve repair. DR CAMPANELLA: I asked you because it seems to me a great deal of repair to do afterward. DR GUIRAUDON: The closure can be done in a short time. The repair of the right atrium can be done after unclamping the aorta when the left atrium is securely closed. I know well the technique described by Charles DuBost (his name was misspelled Dubots in his original paper). Like many users of this technique, such as Doctor Piwnica sitting beside you, I found its repair difficult, frequently requiring an atrial patch to close. DR JOACHIM LAAS (Hannover, Germany): I support Dr Guiraudon s view that the transection of the artery in the left

5 ~ 1062 GUIRAUDON ET AL 1991;52:105%62 atrial roof is not that important for maintenance of sinus rhythm. My colleagues and I have published a series of 100 mitral valves operated on consecutively using the superior approach. Thirty percent of these patients were in sinus rhythm before and after operation. So we believe that transection of the left atrial roof is not of importance with respect to sinus rhythm. I am a little concerned about one of the intraoperative slides shown. The incision was quite close to the aortic root where the roof of the left atrium is very thin. Furthermore, in the same slide, the distance of the right coronary artery was very small. Dr Guiraudon, did you have any problems with bleeding after closing the left atrial incis ion, and was there any obstruction of the right coronary artery? DR GUIRAUDON: I had no complications associated with the repair of the left atriotomy. I usually take large bites. The right coronary artery is easy to identify and spare. DR ARMAND PIWNICA (Paris, France): We have to face more and more reoperations, second-time and third-time patients, with reconstructive operations or a bioprosthesis, and the approach described by Dr Guiraudon and associates is very important, because in some cases the left atrium becomes smaller and smaller. So we are very happy to use the transseptal approach. DR GUIRAUDON: Thank you Dr Piwnica. When the extended vertical transseptal approach is used during a redo operation, a minimal dissection of adhesions is required to expose only the aorta and the right atrium. REVIEW OF RECENT BOOKS The Foundations of Cardiac Pacing, Part I. An Illustrated Practical Guide to Basic Pacing By Richard Sutton and lvan Bourgeois Mount Kisco, NY, Futura, pp, illustrated, $65.00 Reviewed by lames L. Nielsen, M D The beneficiaries of the information in this book include not only cardiologists-in-training, but any physician who comes in contact with cardiac pacemakers on a routine basis. This is probably even more so for those dealing with pacers on an intermittent basis. This book begins with explanations of basic cardiac electrophysiology and practical applications of clinical electrophysiology. The basic concepts and actual composition of a modem pacemaker are extensively discussed, as are pacemaker indications, selection, and implantation. As the pacemaker patient is an ongoing concern, the authors have included chapters on extensive trouble-shooting and clinical follow-up to facilitate patient management. They also discuss the impact of pacemakers on the health care system here and abroad, and in later chapters prognosticate about the future of cardiac pacing. Throughout the book, the text is well organized and concise, with clinical examples and clear illustrations used in a complimentary fashion. The chapters are arranged such that those readers who want to review certain topics can easily locate specific information. As an introduction to pacemakers and their use, this wellwritten book is an excellent foundation. Sun Antonio, Texas