Video-Assisted Mitral Valve Operations

Transcription

1 Video-Assisted Mitral Valve Operations Pyng Jing Lin, MD, Chau-Hsiung Chang, MD, Jaw-Ji Chu, MD, Hui-Ping Liu, MD, Feng-Chun Tsai, MD, Po-Hsien Chu, MD, Cheng-Wen Chiang, MD, Min-Wen Yang, MD, Ming-Hwang Shyr, MD, PhD, and Peter P. C. Tan, MD Division of Thoracic and Cardiovascular Surgery, Division of Cardiology, and Department of Anesthesiology, Chang Gung Memorial Hospital, Chang Gung Medical College, Taipei, Taiwan, Republic of China Background. Video-assisted endoscopy has been applied frequently in the management of a variety of surgical diseases. However, it has rarely been applied in mitral valve surgery. Methods. We report 2 patients who received emergency operations for thrombosis of a mitral prosthesis (patient 1, a 68-year-old man) and acute mitral regurgitation due to rupture of anterior chordae (patient 2, a 75-year-old woman). They both had severe congestive heart failure. Cardiogenic shock was noted in patient 2. The mitral valve was approached through a right anterior minithoracotomy with the aid of an endoscope by means of projected images on the video monitor under femorofemoral cardiopulmonary bypass. The aorta was not cross-clamped, and the myocardium was protected by continuous coronary perfusion with hypothermic fibrillatory arrest. The left atrium was entered posterior to the interatrial groove. Thrombectomy and mitral valve repair were performed successfully. Results. The duration of extracorporeal circulation was 204 and 147 minutes, respectively. Both patients recovered from the operation rapidly with uneventful postoperative courses. Conclusions. Our preliminary results suggest that video-assisted endoscopic cardiac surgery is technically feasible and could be performed in the milieu of open heart surgery. (Ann Thorac Surg 1996;61:1781-7) D espite the wide application of video-assisted techniques in thoracic surgery [1-3], the majority of cardiac surgeons hardly have any experience with these techniques. The application of this technique offers safety, minimal discomfort, quick functional recovery, excellent cosmetic healing, and savings in cost [3]. Videoassisted endoscopic techniques have been used in surgical correction of coronary or congenital cardiac lesions that did not need extracorporeal circulation [4-6]. Animal experiments with canine hearts using video-assisted endoscopic techniques have been performed since the beginning of 1995 in our laboratory. We report our preliminary experience of video-assisted cardiac surgery (VACS) in 2 patients (Table 1) with class IV congestive heart failure due to thrombosis of mechanical mitral prosthesis or acute severe mitral regurgitation, respectively. Case Reports Patient 1 A 68-year-old male patient was admitted in September 1995 with severe orthopnea and dyspnea on exertion, which had developed in the past month. He received mitral valve replacement with a 29-mm Sorin valve (Sorin Biomedica SpA, Saluggia, Italy) in August 1987 as a result of rheumatic mitral stenosis, but he was soon lost Accepted for publication Feb 10, Address reprint requests to Dr Lin, Division of Thoracic & Cardiovascular Surgery, Chang Gung Memorial Hospital, 199, Tun-Hwa North Rd, Taipei, Taiwan, Republic of China. to follow-up. Anticoagulant was taken intermittently in the first few postoperative years, but he had not taken any anticoagulant in the past 4 years. A transesophageal echocardiograrn (Fig 1A) revealed increased echodensity over the prosthetic valve, indicating thrombus in the prosthetic valve. A floating linear density was found over the left atrial wall near the mitral prosthesis. The mitral area was estimated to be 2.05 cm. 2 Some echodense shadows presumed to be thrombi were found at the left atrial roof, and mild aortic regurgitation was also found. Emergency operation for thrombectomy of the mitral prosthesis was performed 96 months after his first cardiac operation [7]. Video-assisted techniques using an endoscope were applied through a right anterior minithoracotomy to avoid time-consuming, possibly dangerous, median resternotomy and extensive mediastinal dissection. Written consent was obtained from the family members before the operation. After induction of general anesthesia, transesophageal echocardiographic monitoring was set up and the patient was put in a left semidecubitus position. Extracorporeal circulation was established immediately, due to unstable hemodynamics, through cannulation of the right femoral artery with a 21F aortic cannula (THI aortic perfusion cannula; Argyle, Division of Sherwood Medical, St. Louis, MO) and the right femoral vein with a 32F chest tube (Thoracic catheter; Mallinckrodt Laboratories, Athlone, Ireland). A membranous oxygenator (Maxima Plus oxygenation system; Medtronic, Inc, Cardiopulrnonary Division, Anaheim, CA) was used. The systemic temperature was kept around 36 C to keep the heart beating and to avoid left ventricular distention by The Socie~ of Thoracic Surgeons /96/$15.00 Published by Elsevier Science lnc PII S (96)

2 1782 LIN ET AL Ann Thorac Surg VIDEO-ASSISTED MITRAL OPERATIONS 1996;61: Table 1. Patient Data Variable Patient 1 Patient 2 Age (y) Sex Male Female Mitral lesion Thrombosis Rupture of chordae Congestive heart failure Class 1V Class 1V Mechanical ventilation No Yes preoperatively Duration of bypass (min) Stay in ICU (days) 4 5 Stay in hospital postoperatively (days) 1cu = intensive care unit. A 2-cm incision was made over the third intercostal space at the anterior axillary line, followed by entry of the chest through a stab incision (Fig 2). An 11-mm nondisposable trocar was inserted, through which the endoscope (Stryker Endoscopy, San Jose, CA) was inserted. A right anterior minithoracotomy (10 cm in length) (see Fig 2) through the fourth intercostal space was made as the "manipulation incision" for introduction of conventional surgical instruments into the chest and the left atrium [8]. A small rib retractor was used to facilitate insertion of instruments through this incision. An incision was created on the pericardium anterior to the phrenic nerve. The pericardium was carefully dissected away from the right atrium, and the previous suture line of left atriotomy was identified posterior to the interatrial groove. Other parts of the heart and aorta were not dissected out. Systemic hypothermia (22 C) began at this time. A stab incision 4 cm in length was made along the previous atriotomy suture line after the ventricle fibrillated and the left atrium was entered. The aorta was not crossclamped. The heart was perfused continuously, although fibrillated. The endoscope was advanced to enter the left atrium, and the entire left atrial cavity was carefully explored by means of projected images on the video monitor. Fresh thrombi were found on the left atrial roof and were removed by ring forceps or open-tipped suction. Organized thrombi were found to fill the opening of the mechanical mitral prosthesis. The thrombotic material was all removed using biopsy forceps (ENDO Grasp; Auto Suture Company, United States Surgical Corporation, Norwalk, CT) under the guidance of the endoscope. The thrombi on the ventricular side of the prosthesis ~1,~i! ~ i C Fig 1. (A) Preoperative echocardiogram of patient 1. (B) Postoperative echocardiogram of patient 1. (C) Preoperative echocardiogram of patient 2. (D) Postoperative echocardiogram of patient 2.

3 Ann Thorac Surg LIN ET AL ;61: VIDEO-ASSISTED MITRAL OPERATIONS the anterior and posterior axillary line for insertion of the drainage tubes (see Fig 2). Hemostasis and closure of the incision were easily achieved. The postoperative course was uneventful with no organ failure. Warfarin was prescribed for anticoagulation. The patient was followed up regularly for 3 months in the outpatient clinic in New York Heart Association functional class I. Echocardiography showed adequate mitral prosthetic function with good left ventricular function. Fig 2. Incision sites in patient 1. Double arrowhead indicates thoracotomy for introduction of the thoracoscope. Arrow indicates manipulation incision. Large arrowhead indicates thoracotomies created for drainage. Double arrow indicates previous sternotomy incision. were removed by using nerve hood and biopsy forceps. The leaking blood from the regurgitated aortic valve was sucked out by a suction tube (Left ventricular sump vent catheter with Cath-Lok and sentinel line; Argyle) inserted into the left ventricle through the mitral prosthesis opening. During the thrombectomy, the right atrium was not distended, indicating that the venous return was smooth. At termination of the thrombectomy the disc mechanism was found to be free of any mechanical impairment and the disc had free motion. After the left atrium and left ventricle were meticulously cleansed, they were filled with blood by slowing down the femoral venous drainage and ventilating the lungs. The air was carefully evacuated by rotating the operating table in all directions. The atriotomy was then closed with 4-0 Prolene (Ethicon, Ltd, UK) running suture, after which no obvious air bubble was noted by transesophageal echocardiographic examination. The patient was kept in a head-down position. Cardioversion was easily performed by putting the cardioverter (CodeMaster; Hewlett-Packard Company, Mc- Minnville, OR) pads on the right upper and left lower anterior chest wall. Extracorporeal circulation was terminated after rewarming of the patient. The bypass time was 204 minutes. Intraoperative transesophageal echocardiographic examination showed smooth opening of the disc of the mitral prosthesis with a mitral area of 2.73 Cln 2 (Fig 1B). There was no thrombosis noted. The pericardium was not closed. Dobutamine and sodium nitroprusside were infused in small doses to stabilize the hemodynamics. A pacemaker was not used. Two stab incisions were made in the seventh intercostal space in Patient 2 A 75-year-old woman was admitted on September 1995 with severe orthopnea and dyspnea on exertion that had developed in the past week. There had been no history of fever or chest discomfort recently. A holosystolic murmur was audible at the apex. A chest roentgenogram revealed acute pulmonary edema, and an echocardiogram showed severe mitral regurgitation with flail anterior leaflet due to rupture of chordae tendineae (Fig 1C). Cardiogenic shock developed 2 days after admission despite the use of dobutamine and sodium nitroprusside; therefore an emergency operation was arranged in an attempt to repair the mitral valve [9]. Written consent was obtained from the family members before the operation. The video-assisted techniques used on this patient were basically the same as those in patient 1. Systemic hypothermia (20 C) began immediately after the start of femorofemoral extracorporeal circulation (Fig 3A). With the guide of an endoscope, which was inserted through a thoracotomy created in the third intercostal space in the anterior axillary line (Fig 3B), the pericardium was incised anterior to the right phrenic nerve and the left atrium was entered posterior to the interatrial groove after the ventricle fibrillated. The heart was protected with continuous coronary perfusion and hypothermic fibrillation. The entire left atrial cavity was carefully explored by endoscope and no thrombus was found. Rupture of the central primary chordae tendineae of the anterior leaflet of the mitral valve had occurred (Fig 3C), so the mitral valve was repaired with (1) plication of the anterior leaflet by hand-suturing the two chordae next to the ruptured one together and (2) annuloplasty with conventional instruments inserted through the manipulation incision under the guidance of the endoscope (Fig 3D). Mitral valve competence was evaluated by the left ventricular extension method, which showed good competence. After deairing of the left ventricle and atrium, the left atriotomy was closed and decannulation and closure were then performed. The bypass time was 147 minutes. Transesophageal echocardiographic examination showed a good coaptation of the leaflets (Fig 1D). The mitral valve area was estimated to be 2.80 cm 2. The postoperative course was uneventful. The patient was followed up regularly for 2.5 months in the outpatient clinic in New York Heart Association functional class II. Echocardiography showed trivial mitral regurgitation.

4 1784 LIN ET AL Ann Thorac Surg VIDEO-ASSISTED MITRAL OPERATIONS 1996;61: Fig 3. Pictures of mitral valve repair of patient 2 taken by video-assisted endoscope. (A) Isolation of right femoral artery and vein for extracorporeal circulation. (B) Thoracotomy created for introduction of the thoracoscope. (C) Severe mitral regurgitation was demonstrated. (D) The mitral valve was repaired with annuloplasty. Comment We report 2 patients who were operated on in an emergency condition with the aid of VACS techniques. They were critically ill due to thrombotic obstruction of the mechanical mitral prosthesis and acute mitral regurgitation with cardiogenic shock, respectively. However, they both recovered rapidly from the operations. The VACS techniques offer avoidance of sternotomy, minimal mediastinal dissection, and minimal operative incision, which is desirable in these severely ill patients. Thrombotic obstruction is a rare but often fatal complication of cardiac mechanical valve prostheses. This type of complication occurs more frequently in tiltingdisc valves than in other kinds of prostheses [7]. Surgical treatment of disc valve thrombosis includes thrombectomy or replacement of the prosthetic valve [7, 10, 111. Our previous experience showed that thrombectomy is an easy, fast, and safe procedure, especially for those critically ill patients [7]. Thrombectomy was successfully performed in our first patient, who recovered rapidly. Surgical treatment of mitral regurgitation has been the subject of numerous reports. By using valve repair, the well-recognized complications of valve replacement-- bioprosthetic degeneration, prosthetic valve infection, transvalvular gradients, paravalvular leak, hemolysis, and thromboembolic events--are avoided [9, 12]. Our second patient suffered from severe mitral regurgitation with cardiogenic shock due to rupture of the chordae of the anterior leaflet of the mitral valve. Mitral valve repair, which was successfully accomplished, should be the best procedure for this older patient. Since the first reports by Dr Ralph Lewis and his associates [1] in 1991, video-assisted techniques have been useful for surgical treatment of many intrathoracic diseases [2-6]. The problems of application and manipulation of this technique in cardiac operations are (1) the method of cardiopulmonary bypass, (2) the technique of myocardial protection, (3) the development of new instruments to be used through small trocar channels for cardiac procedures, (4) the possibility of air embolization, and (5) difficulty in hemostasis. Cardiopulmonary bypass has been executed through cannulation of the peripheral arteries and veins, such as femoral artery and vein [13, 14], with excellent results. In our patients, simple femorofemoral bypass via the right femoral artery and vein could establish satisfactory cardiopulmonary bypass with adequate perfusion of all vital organs, including the brain. There was no organ

5 Ann Thorac Surg LIN ET AL ;61: VIDEO-ASSISTED MITRAL OPERATIONS failure postoperatively. Patients regained consciousness promptly after the operation. Infusion of cardioplegic solution, crystalloid or blood, antegradely via the aortic root or retrogradely through the coronary sinus, with the aortic cross-clamped, was the gold standard of myocardial protection in most cardiac operations. However, continuous perfusion of the heart without cross-clamping of the ascending aorta can still offer adequate myocardial protection [15, 16]. With continuous coronary perfusion under hypothermic fibrillation, there was no low cardiac output postoperatively, indicating adequate myocardial protection. Video-assisted operations in thoracic or abdominal diseases have been accompanied by the extensive application of expensive disposable endoscopic instruments. The delay in development of these instruments for endoscopic cardiac surgery had certainly postponed the advancement of these surgical skills. Our experience in video-assisted thoracic operations [3, 8] indicates that routine use of conventional nondisposable instruments can achieve a truly cost-effective and minimally invasive video-assisted procedure. In the operations for our patients, the creation of a manipulation incision made use of conventional instruments, dissection, grasping, suturing, removal of thrombi, and control of the hemorrhage much easier and faster. We did not use any disposable endoscopic instruments in these operations. Air embolization occasionally causes trouble after a smooth cardiac operation. Adequate evacuation of the intracavitary air by filling the heart with blood or saline solution before closure of the cardiotomy is the rule [17]. We rotated the operating table in all directions while deairing and filled the left atrium and ventricle carefully with blood. The patients were kept in a head-down position. There were no obvious air bubbles in the heart noted by transesophageal echocardiographic examination [18, 19] before the heart started beating. Both our patients woke up from the anesthesia promptly after arriving at the intensive care unit. There was no evidence of neurologic defect. However, larger series of patients will be required to demonstrate the incidence of neurologic complications of VACS. Cardioversion was not a problem in our patients. Defibrillation could be easily performed by putting the pads on the surface of the chest wall (patient 1) or the heart (patient 2). Hemostasis was easily established through the extended manipulation incision. Conventional hand-suturing for all cardiotomies could be performed smoothly through the manipulation incision with the guidance of endoscope to reduce the chance of bleeding from the suture lines to a minimum. Any bleeder could be easily controlled by hand sutures or electric cautery. Small incisions without sternotomy, minimal mediastinal dissection, and no incision on the high-pressure system of the heart (such as aorta or left ventricle) were also helpful for hemostasis. The major advantage of VACS is the avoidance of a sternotomy. It minimizes mediastinal trauma, and hence decreases the chance of major injuries to the cardiac chambers or great vessels, especially in cases of redo operations. The minimally invasive nature of VACS will reduce the incidence of postoperative mediastinitis and pulmonary insufficiency to a minimum. As in videoassisted thoracic surgery, the application of VACS might offer the promise of expediency, safety, minimal discomfort, less postoperative pain, quick functional recuperation, and excellent cosmetic healing [3]. These advantages are particularly helpful in patients who are critically ill, as in our patients. From our experience, video-assisted mitral valve operations can be carried out with femorofemoral cardiopulmonary bypass, continuous coronary perfusion with hypothermic fibrillation, and conventional instruments without much difficulty through the extended manipulation incision. Deairing and hemostasis were easily accomplished and were very similar to the techniques used in standard open heart operations. However, our experience is still limited. The bypass time and the length of the manipulation incision were rather long due to unfamiliarity of the VACS techniques. The number of patients and operations are too few to make conclusions. The incidence of neurologic complications and the benefit of shortened hospital stay, seen in other video-assisted procedures [3], of VACS remain to be demonstrated. Nevertheless, our preliminary experience using VACS techniques in mitral valve operations is encouraging. Patients recovered rapidly from the operations, indicating that the advantages of VACS can overcome the technical difficulties in the learning period. With more experience, the bypass time and the length of the manipulation incision will be shortened. These initial results demonstrate that VACS is technically feasible and can be effectively executed in a minimally invasive manner. We believe that video-assisted technologies could be applied in the milieu of open heart surgery. We anticipate a striking extended role for VACS in major cardiac procedures in the near future. References 1. Lewis RJ, Caccavale RJ, Sisler GE. Special report: videoendoscopic thoracic surgery. N Engl J Med 1991;88: Landreneau RJ, Mack MJ, Hazelrigg SR, et al. Video-assisted thoracic surgery: basic technical concepts and intercostal approach strategies. Ann Thorac Surg 1992;54: Liu HP, Chang CH, Lin PJ, Hsieh HC, Chang JP, Hsieh MJ. Video-assisted thoracic surgery--the Chang Gung experience. J Thorac Cardiovasc Surg 1994;108: Burke RP, Wernovsky G, van der Velde M, Hansen D, Castafieda AR. Video-assisted thoracoscopic surgery for congenital heart disease. J Thorac Cardiovasc Surg 1995;109: Burke RP, Chang AC. Video-assisted thoracoscopic division of a vascular ring in an infant: a new operative technique. J Cardiac Surg 1993;8: Benetti FJ, Ballester C. Use of thoracoscopy and a minimal thoracotomy, in mammary-coronary bypass to left anterior descending artery, without extracorporeal circulation. Experience in 2 cases. J Cardiovasc Surg 1995;36:

6 1786 L1N ET AL Ann Thorac Surg VIDEO-ASSISTED M1TRAL OPERAF1ONS 1996;61: Tsai KT, Lin PJ, Chang CH, et al. Surgical management of thrombotic disc valve. Ann Thorac Surg 1993;55: Liu HP, Lin PJ, Chang JP, et al. Video assisted thoracic surgery--manipulation without trocar in 112 consecutive procedures. Chest 1993;104: Chang CH, Lin PJ, Chang JP, et al. Long-term results of polytertrafluoroethylene annuloplasty in 73 patients with mitral regurgitation. Ann Thorac Surg 1994;57: Byrd CL, Yahr WZ, Greenberg JJ. Long-term results of "simple" thrombectomy for thrombosed Bj6rk-Shiley aortic valve prostheses. Ann Thorac Surg 1975;20: Gray LA Jr, Fulton RL, Srivastava TN, Flowers NC. Surgical treatment of thrombosed Bj/Srk-Shiley aortic valve prostheses. J Thorac Cardiovasc Surg 1976;71: Murphy JP Jr, Sweeney MS, Cooley DA. The Puig-Massana- Shiley annuloplasty ring for mitral valve repair: experience in 126 patients. Ann Thorac Surg 1987;43: Kirklin JW, Barratt-Boyes BG. Cardiopulmonary bypass established by peripheral cannulation. In: Kirklin JW, Barratt- Boyes BG, eds. Cardiac surgery, second ed. New York: Churchill Livingstone, 1993: Lin PJ, Chang CH, Tan PPC, et al. Protection of the brain by retrograde cerebral perfusion during circulatory arrest. J Thorac Cardiovasc Surg 1994;108: Akins CW. Noncardioplegic myocardial preservation for coronary revascularization. J Thorac Cardiovasc Surg 1984; 88: Akins CW, Carroll DL. Event-free survival following nonemergency myocardial revascularization during hypothermic fibrillatory arrest. Ann Thorac Surg 1987;43: Kirklin JW, Barratt-Boyes BG. De-airing the heart. In: Kirklin JW, Barratt-Boyes BG, eds. Cardiac surgery, second ed. New York: Churchill Livingstone, 1993: Spotnitz HM, Maim JR. Two-dimensional ultrasound and cardiac operations. J Thorac Cardiovasc Surg 1982;83: Furuya H, Suzuki T, Okumura F, Kishi Y, Uefuji T. Detection of air embolism by transesophageal echocardiography. Anesthesiology 1983;58: INVITED COMMENTARY Small incisions and a variety of instruments and videoscopes designed to allow minimally invasive operations are currently revolutionizing many surgical disciplines. Although the technical challenges are great when considering cardiac operations, Dr Pyng Jing Lin and colleagues from the Chang Gung Memorial Hospital in Taipei, Taiwan, are to be congratulated for their early efforts. In their report, 2 patients with mitral valve disease were treated by a small anterior thoracotomy incision with assisted visualization using a video thoracoscope. The clotted mitral prosthesis in 1 patient was debrided, and the mitral regurgitation created when a chordal rupture occurred was effectively repaired. Lin and associates clearly point out that their operative times, cardiopulmonary bypass times, and lengths of stay in both the intensive care unit and in the hospital are not different from standard mitral valve operations. In fact, the intraoperative times are probably considerably prolonged. However, the early results in these 2 patients are promising and suggest that, even with these deficiencies, the patients made nice recoveries and were doing well at follow-up. Approaching the heart through smaller and smaller incisions provides many challenges for the surgeon. A concerted effort requires addressing each of them. The first of these is to obtain optimum visualization at all times. Current video technology, as used in the patients at Chang Gung, seems to be satisfactory for most applications. Direct vision may also be feasible, as in minithoracotomy for left internal mammary bypass to the left anterior descending artery. However, further efforts at creating a three-dimensional video image will be particularly helpful for cardiac surgeons operating on the heart. The second challenge is the ability to perform all of the necessary technical maneuvers. Because the access is through limited incisions, many of the currently available instruments will need to be modified for these new approaches. Shafted forceps, needle holders, retractors, and others may need to be developed. Some may be available from currently developed laparoscopic instruments, but certainly the surgeon will require additional tools specifically constructed for heart surgery. The third challenge will be to provide adequate myocardial protection that is at least the equivalent of that currently achieved with conventional open surgery. This report uses fibrillation with the aorta unclamped; however, this technique would seldom be used for mitral valve surgery with current open operations. Thus, a method to provide standard cardioplegic arrest and a bloodless operative field would be preferred, or indeed be mandatory. Lin and associates' first patient had aortic regurgitation, and anyone who has operated on the fibrillating heart in the presence of aortic regurgitation knows the tremendous technical disadvantage that this creates. An alternative approach using an endovascular balloon aortic clamp on a catheter-based system is currently being tested at Stanford. Both coronary artery bypass and mitral valve replacement are facilitated by its use, as demonstrated by experimental studies in our laboratory, as well as a clinical study of single-vessel coronary artery bypass. Further clinical application of the endovascular balloon clamp will soon be forthcoming. This seems to us to be the current best method for producing cardioplegic arrest of the heart, although undoubtedly other technologies will be developed. A further technical challenge that needs to be dealt with is the ability to assess the heart and treat both expected and unexpected findings or complications encountered during the course of the operation. It should be clear that surgeons should not compromise the quality of the operative repair because of the efforts at using small incisions. If some element of the procedure is considered essential for obtaining an excellent result, it

7 Ann Thorac Surg LIN ET AL ;61: VIDEO-ASSISTED MITRAL OPERATIONS should not be eliminated or altered in the course of the minimally invasive approach; for example, moving toward mitral valve replacement rather than repair because of a technical limitation of the minimally invasive approach. Morbidity associated with the new approach should not be substantially greater than that of standard operations, so that the anticipated benefits of minimally invasive approaches are achieved. In this regard, Lin and associates mentioned the absence of neurologic complications, but pointed out the difficulties with adequate deairing of the heart from the minimally invasive approach. This will be the subject of many investigations, and talented surgeons will undoubtedly develop methods for overcoming this potential problem. In addition, the morbidity associated with femoral artery and vein cannulation with respect to perfusion, as well as thrombosis of the femoral vein and possible pulmonary embolism, must be within acceptable limits to justify the new approach. It is yet to be determined whether the economic and patient comfort benefits that usually accompany mini- mally invasive approaches are in fact realized. Early data from several centers performing minimally invasive coronary artery bypass using the left internal mammary artery to the left anterior descending artery, both with a beating heart and with the arrested heart, support the concept that patients recover quickly and are able to return to work in a much shorter time than with conventional median sternotomy. More data are required, however, before firm conclusions can be made. Undoubtedly, reports will now come in rapid succession, testing new technologies and techniques for performing minimally invasive cardiac operations. Already very technically oriented and innovative, cardiac surgeons will continue to refine the methods they use to benefit their patients in much the same way that Dr Pyng Jing Lin and colleagues have done. Bruce A. Reitz, MD Department of Cardiothoracic Surgery Stanford University School of Medicine Stanford, CA Notice From the American Board of Thoracic Surgery The part I (written) examination will be held at the Atlanta Airport Hilton and Towers, Atlanta Airport, Atlanta, GA, on February 9, The closing date for registration is August 1, To be admissible for the part II (oral) examination, a candidate must have successfully completed the part I (written) examination. A candidate applying for admission to the certifying examination must fulfill all the requirements of the board in force at the time the application is received. Please address all communications to the American Board of Thoracic Surgery, One Rotary Center, Suite 803, Evanston, IL