Video-Assisted Coronary Artery Bypass Grafting During Hypothermic Fibrillatory Arrest

Transcription

1 Video-Assisted Coronary Artery Bypass Grafting During Hypothermic Fibrillatory Arrest Pyng Jing Lin, MD, Chau-Hsiung Chang, MD, Jaw-Ji Chu, MD, Hui-Ping Liu, MD, Feng-Chun Tsai, MD, Fen-Chiung Lin, MD, Cheng-Wen Chiang, MD, Min-Wen Yang, MD, and Peter P. C. Tan, MD Divisions of Thoracic and Cardiovascular Surgery and Cardiology and Department of Anesthesiology, Chang Gung Memorial Hospital, Chang Gung Medical College, Taipei, Taiwan, Republic of China Background. Hypothermic fibrillatory arrest without aortic cross-clamping is a technique for quieting the heart during coronary artery bypass grafting. This report reviews the preliminary results with this technique in 4 patients having video-assisted coronary artery bypass grafting. Methods. Four male patients 28.5 to 64.5 years old (mean age, 45.4 years) underwent operation for unstable angina. With video-assisted techniques, coronary artery bypass grafting was performed through a left anterior minithoracotomy with femoral-femoral cardiopulmonary bypass without cross-clamping the aorta. The myocardium was protected by continuous coronary perfusion during hypothermic fibrillatory arrest. Results. A left internal thoracic artery graft was anastomosed to the left anterior descending coronary artery in each patient. The posterior descending branch of the right coronary artery was grafted with a pedicled right gastroepiploic artery in 1 patient. The duration of cardiopulmonary bypass was 72 to 127 minutes (mean duration, minutes). The postoperative course of each patient was uneventful. Follow-up (range, 3.9 to 5.8 months; mean follow-up, 4.9 months) was complete for all patients. There were no late deaths. Coronary angiography showed patent grafts. All patients were in New York Heart Association functional class I or II (mean class, 1.25). Conclusions. Hypothermic fibrillatory arrest is a simple and effective method of quieting the heart, thereby providing a motionless operative field for video-assisted coronary artery bypass grafting. (Ann Thorac Surg 1997;63:1113 7) 1997 by The Society of Thoracic Surgeons Accepted for publication Nov 5, Address reprint requests to Dr Lin, Division of Thoracic and Cardiovascular Surgery, Chang Gung Memorial Hospital, 199, Tun-Hwa North Rd, Taipei, Taiwan 10591, Republic of China. Infusion of cardioplegic solution, crystalloid or blood, antegradely through the aortic root or retrogradely through the coronary sinus with the aorta cross-clamped are standard methods of myocardial protection in most cardiac operations. However, hypothermic fibrillatory arrest (HFA) without infusion of cardioplegic solution is a technique that has been used in cardiac surgery, especially for various subgroups of patients with coronary artery disease [1]. Video-assisted endoscopic techniques have been applied to the surgical correction of coronary or congenital cardiac lesions that do not require cardiopulmonary bypass [2, 3]. Recently, video-assisted cardiac operations have been done to correct intracardiac lesions [4 6]. These operations were performed through a right anterior minithoracotomy and were guided by video-assisted endoscopic techniques. Femoral-femoral or femoral right atrial cardiopulmonary bypass was used, and the aorta was not cross-clamped. The myocardium was protected by continuous coronary perfusion during HFA without infusion of cardioplegic solution. Coronary artery bypass grafting (CABG) is traditionally performed through a median sternotomy. Recently, it has been carried out through a limited left anterior thoracotomy without [3] or with [7] cardiopulmonary bypass. Here we review our initial results of videoassisted CABG during HFA. Material and Methods Patient Population Four male patients 28.5 to 64.5 years old (mean age, 45.4 years) underwent operation for unstable angina (Table 1). An acute myocardial infarction had occurred in patients 2 and 4. Coronary angiograms showed one-vessel disease (left anterior descending coronary artery: 64%, 100%, and 90% stenosis, in patients 2, 3, and 4, respectively) in 3 patients and two-vessel disease (left anterior descending coronary artery and right coronary artery: 86% and 100% stenosis, respectively) in 1 patient. Percutaneous transluminal coronary angioplasty had been performed twice on patient 4. The left ventricular ejection fraction ranged from 0.51 to 0.72 (mean ejection fraction, ). Written consent was obtained from the patient and the family members before the operation. Video-Assisted Coronary Artery Bypass Grafting The video-assisted techniques with some modifications have been previously reported [4 6]. After induction of 1997 by The Society of Thoracic Surgeons /97/$17.00 Published by Elsevier Science Inc PII S (97)

2 1114 LIN ET AL Ann Thorac Surg VIDEO-ASSISTED CABG 1997;63: Table 1. Summary of Patient Data Variable Patient No Age (y) Sex Male Male Male Male Angina Unstable Unstable Unstable Unstable AMI No Yes No Yes Coronary lesion LAD, RCA LAD LAD LAD PTCA No No No Twice LVEF AMI acute myocardial infarction; LAD left anterior descending coronary artery; LVEF left ventricular ejection fraction; PTCA percutaneous transluminal coronary angioplasty; RCA right coronary artery. general anesthesia, transesophageal echocardiographic monitoring was established, and the regional wall motion abnormality was determined. The patient was put in a supine position with exposure of the left groin. A left anterior submammary minithoracotomy (length, 8 to 10 cm) was performed, and the pleural space was entered through the fourth intercostal space (Fig 1). The cartilage portion of the fourth rib was resected. Care was taken not to damage the underlying left internal thoracic artery. The left internal thoracic artery was identified beside the sternal border and was isolated from the second to the fifth intercostal space with the help of a video-assisted endoscope (Stryker Endoscopy, San Jose, CA), which was inserted through a thoracostomy incision. In patient 1 with stenosis of the right coronary artery, a pedicled right gastroepiploic artery graft was prepared through a limited upper median laparotomy. After isolation of the left internal thoracic artery and Fig 2. Anastomosis of left internal thoracic artery (arrow) to left anterior descending coronary artery (arrowhead). the right gastroepiploic artery, cardiopulmonary bypass was established by cannulation of the left femoral artery and the left femoral vein. A membranous oxygenator (Maxima Plus oxygenation system; Medtronic Cardiopulmonary Division, Anaheim, CA) was used. Systemic hypothermia (rectal temperature, C) was begun immediately after the start of cardiopulmonary bypass. Topical cooling of the heart was not done. The heart fibrillated spontaneously soon after it cooled. The aorta was not cross-clamped, and the myocardium was protected by continuous coronary perfusion from the aorta throughout HFA. Cardioplegic solution was not used. The heart was decompressed by left ventricular venting or pulmonary artery venting with a suction catheter (left ventricular sump vent catheter with Cath- Lok and Sentinel Line; Argyle, Division of Sherwood Fig 1. Incisions used (arrow left anterior minithoracotomy.) Fig 3. Anastomosis of right gastroepiploic artery (white arrow) to posterior descending branch of right coronary artery (black arrowhead). The right gastroepiploic artery is surrounded by omental fat.

3 Ann Thorac Surg LIN ET AL 1997;63: VIDEO-ASSISTED CABG 1115 Table 2. Summary of Operative Data Variable Patient No Bypassed graft LITA, RGEA LITA LITA LITA Duration of CPB (min) Rectal temperature a ( C) Time of operation (h) Postoperative hospital stay (days) Follow-up (mo) a This was the lowest rectal temperature during extracorporeal circulation. CPB cardiopulmonary bypass; LITA left internal thoracic artery; RGEA right gastroepiploic artery. Medical, St. Louis, MO) placed through a stab incision on the main pulmonary artery or the apex of the left ventricle under endoscopic guidance. The left anterior descending coronary artery was identified. The anastomotic area was cleared of blood by air pressure (Laparoflator Electronic 3509; F.M. Wiest Medizintechnik, München, Germany). Local control of the coronary arteries proximal or distal to the arteriotomy was not performed. During HFA and with air pressure, the coronary artery anastomotic area was steady, motionless, and bloodless, which made the anastomosis easy and smooth. The left internal thoracic artery was connected to the left anterior descending coronary artery with a running suture under direct vision (Fig 2), with the video-assisted endoscope used for better illumination of the operative field. In patient 1, the right gastroepiploic artery was brought into the operative field through a small stab incision in the diaphragm and grafted to the posterior descending branch of the right coronary artery (Fig 3). This anastomosis was performed with the assistance of an endoscope, which was necessary because of the poorly accesible anastomotic site. Conventional nondisposable instruments were used for dissection, grasping, suturing, and hemostasis. Cardioversion was easily accomplished by putting two small cardioverter pads (CodeMaster; Hewlett-Packard Company, McMinnville, OR) on the surface of the heart. Sinus rhythm returned in all patients. Cardiopulmonary bypass was terminated after the patients were rewarmed. The pericardium was not closed. A small dose of sodium nitroprusside was infused. Cardiotonic drugs were not used. Temporary pacemaker wires and pleural drainage were set up routinely. Hemostasis and closure of the incisions were easily achieved. (mean time, hours). All patients regained consciousness without any neurologic deficit shortly after arrival in the intensive care unit. No patient experienced low cardiac output postoperatively. The endotracheal tube was removed on the night of operation. There were no hospital deaths, no perioperative myocardial infarctions, and no wound infections. The postoperative hospital stay was 4 to 7 days (mean stay, 5.5 days). Follow-up (range, 3.9 to 5.8 months; mean follow-up, 4.9 months) was complete for all patients. There were no episodes of angina and no late deaths. Coronary angiograms showed patent grafts (Fig 4). Transthoracic echocardiograms indicated adequate left ventricular performance with ejection fractions of 0.55 to 0.75 (mean ejection fraction, 0.63). All patients were in New York Heart Association functional class I or II (mean class, 1.25), and all were satisfied with the cosmetic healing of the minithoracotomy. Comment Four patients had operation for unstable angina. Coronary artery bypass grafting was performed using an arterial graft or grafts through a left anterior minithoracotomy, guided by a video-assisted endoscope, during femoral-femoral cardiopulmonary bypass and HFA. All patients recovered quickly without any complication. These result indicate that the video-assisted, minimally invasive technique is satisfactory for the surgical correction of coronary artery disease and that HFA is a safe and effective technique of providing a motionless operative field. Coronary artery bypass grafting has been performed on the beating heart without cardiopulmonary bypass [3, 8] by snaring the coronary artery and reducing blood pressure and heart rate pharmacologically. However, the results are not perfect [9]. Further, most cardiac surgeons, Results The duration of cardiopulmonary bypass ranged from 72 to 127 minutes (mean time, minutes) (Table 2). Transesophageal echocardiography performed after the termination of cardiopulmonary bypass indicated improvement in the original focal impairment in all patients. The time of operation ranged from 4.6 to 6.7 hours Fig 4. Coronary angiogram showing patent left internal thoracic artery graft (arrow) anastomosed to left anterior descending coronary artery (arrowhead).

4 1116 LIN ET AL Ann Thorac Surg VIDEO-ASSISTED CABG 1997;63: cannot perform CABG under beating conditions without special training. In cardiac operation, cardiopulmonary bypass can be accomplished by cannulation of the femoral artery and vein [10, 11] with excellent results. In video-assisted cardiac procedures, simple femoral-femoral bypass establishes satisfactory perfusion of all vital organs, including the brain [4 6]. In our series, there was no organ failure postoperatively, and the patients regained consciousness soon after operation, thus indicating adequate tissue perfusion during cardiopulmonary bypass. Infusion of cardioplegic solution is the standard procedure for myocardial protection. However, continuous perfusion of the heart without cross-clamping the ascending aorta can offer adequate myocardial protection [1, 4 6]. Our patients received continuous coronary perfusion during HFA and showed no low cardiac output postoperatively, a finding suggesting adequate myocardial protection. The duration of cardiopulmonary bypass in this series (mean time, minutes) was longer because of our unfamiliarity with the video-assisted endoscopic techniques during this learning period and because of the use of hypothermia. With more experience and better teamwork, the duration of both cardiopulmonary bypass and time of operation will be shortened. Minimally invasive endovascular cardiopulmonary bypass has been used in animal experiments [12 14] and cadaver studies [13]. The method includes the following: (1) a transfemoral clamp for endovascular aortic occlusion, delivery of cardioplegic solution, and left ventricular decompression; (2) a transjugular endovascular pulmonary artery venting catheter; and (3) femoral-femoral cardiopulmonary bypass. With the vascular access, the technique can provide prompt arrest and adequate decompression of the heart and a quiet, bloodless field [12, 13]. More recently, port-access CABG combined with endovascular cardiopulmonary bypass was applied in humans [15]. In our series, HFA also provided prompt cardiac arrest and a steady, motionless operative field. Decompression of the heart and a bloodless field were easily accomplished. Indeed, HFA is a simple and effective method of quieting the heart and can be applied for CABG when the endovascular cardiopulmonary bypass system is not available. Median sternotomy is the gold standard of the surgical approach in CABG. Since the early 1990s, the use of video-assisted endoscopic techniques for the surgical treatment of intrathoracic disease has rapidly expanded [16, 17]. Such techniques have been used for the surgical correction of patent ductus arteriosus and CABG [2, 3]. Recently, we [4 6] have applied video-assisted cardiac surgical techniques to correct intracardiac lesions. The heart is approached by a video-assisted endoscope inserted through a thoracostomy incision, and the intracardiac lesions are repaired through a small manipulation incision above a right anterolateral minithoracotomy. This method avoids sternotomy and requires less mediastinal dissection and smaller operative incisions. Coronary artery bypass grafting through a limited anterior thoracotomy is an operation that is gaining acceptance [3, 7, 18, 19]. However, limited access restricts the indications for this operation to severe disease of the left anterior descending coronary artery [13]. Postoperative angiographic studies have not documented perfect results [19]. The use of cardiopulmonary bypass and the optimal surgical field attained by immobilizing the heart dramatically extend the range of cardiac surgical operations [18]. In our series, the left anterior minithoracotomy allowed broader visualization and access. With the help of an endoscope, the exposure and the grafting of multiple vessels are not difficult. The arrested, decompressed, and protected heart, a state achieved by femoral-femoral cardiopulmonary bypass and continuous coronary perfusion during HFA, allows better exposure and a quiet, bloodless field for precise anastomosis. The major advantage of video-assisted, minimally invasive CABG is avoidance of sternotomy. The minimally invasive nature of this procedure will reduce the incidence of postoperative mediastinitis and wound pain to a minimum. There were no wound infections or mediastinitis in our patients, and all patients were satisfied with the minithoracotomy. The postoperative length of stay in this series was shorter (mean stay, 5.5 days) than that for uncomplicated CABG performed with a median sternotomy (mean stay, 8.2 days; unpublished data), as is the experience of others [3, 19]. These authors demonstrated that video-assisted, minimally invasive CABG offers quick functional recovery, excellent cosmetic healing, and a shorter hospital stay, and therefore, lower medical costs. On the basis of our experience, video-assisted CABG can be carried out safely, easily, and effectively (1) with femoral-femoral cardiopulmonary bypass, (2) with continuous coronary perfusion during HFA, (3) with conventional instruments through a left anterior minithoracotomy, and (4) by grafting with the left internal thoracic artery and the right gastroepiploic artery. References 1. Akins CW. Noncardioplegic myocardial preservation for coronary revascularization. J Thorac Cardiovasc Surg 1984; 88: Burke RP, Wernovsky G, van der Velde M, Hansen D, Castaneda AR. Video-assisted thoracoscopic surgery for congenital heart disease. J Thorac Cardiovasc Surg 1995;109: 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 (Torino) 1995;36: Lin PJ, Chang C-H, Chu J-J, et al. Video-assisted mitral valve operations. Ann Thorac Surg 1996;61: Chang C-H, Lin PJ, Chu J-J, et al. Video-assisted cardiac surgery in closure of atrial septal defect. Ann Thorac Surg 1996;62: Tsai FC, Lin PJ, Chang CH, et al. Video-assisted cardiac surgery: preliminary experience in reoperative mitral valve surgery. Chest 1996;19: Robinson MC, Gross DR, Zeman W, Stedje Larsen E. Minimally invasive coronary artery bypass grafting: a new

5 Ann Thorac Surg LIN ET AL 1997;63: VIDEO-ASSISTED CABG 1117 method using an anterior mediastinotomy. J Card Surg 1995; 10: Kolessov VL. Mammary-artery coronary artery anastomosis as a method of treatment for angina pectoris. J Thorac Cardiovasc Surg 1967;54: Gundry SR. Discussion of Pfister AJ, Zaki MS, Garcia JM, et al. Coronary artery bypass without cardiopulmonary bypass. Ann Thorac Surg 1992;54: Kirklin JW, Barratt-Boyes BG. Cardiopulmonary bypass established by peripheral cannulation. In: Kirklin JW, Barratt- Boyes BG, eds. Cardiac surgery. 2nd ed. New York: Churchill Livingstone, 1993: Lin PJ, Chang C-H, Tan PPC, et al. Protection of the brain by retrograde cerebral perfusion during circulatory arrest. J Thorac Cardiovasc Surg 1994;108: Schwartz DS, Ribakove GH, Grossi EA, et al. Minimally invasive cardiopulmonary bypass with cardioplegic arrest. A closed chest technique with equivalent myocardial protection. J Thorac Cardiovasc Surg 1996;111: Stevens JH, Burdon TA, Peters WS, et al. Port-access coronary artery bypass grafting. A proposed surgical method. J Thorac Cardiovasc Surg 1996;111: Stevens JH, Burdon TA, Siegel LC, et al. Port-access coronary artery bypass with cardioplegic arrest: acute and chronic canine studies. Ann Thorac Surg 1996;62: St Goar FG, Stevens JH, Burdon TA, et al. Closed-chest CABG clinical characteristics: potential for procedural synergy in managing CAD. J Am Coll Cardiol 1996;27(Suppl A):392A. 16. Lewis RJ, Caccavale RJ, Sisler GE. Special report: videoendoscopic thoracic surgery. New Engl J Med 1991;88: Liu H-P, Chang C-H, Lin PJ, Hsieh H-C, Chang J-P, Hsieh M-J. Video-assisted thoracic surgery the Chang Gung experience. J Thorac Cardiovasc Surg 1994;108: Lytle BW. Minimally invasive cardiac surgery. J Thorac Cardiovasc Surg 1996;111: Subramanian VA, Sani G, Benetti FJ, Calafiore AM. Minimally invasive coronary bypass surgery: a multi-center report of preliminary clinical experience [Abstract]. Circulation 1995;92(Suppl 1):645. INVITED COMMENTARY This report by Lin and coauthors is another contribution to the current discussion about modifications in the surgical technique of coronary artery bypass grafting. The thrust of these modifications is to accomplish coronary bypass grafting without the exposure afforded by median sternotomy and thereby hasten the recovery and make the operation more attractive for patients and payers. Lin and associates describe a technique, intermediate between minimally invasive coronary artery bypass grafting and the standard operation, in which sternotomy is avoided in favor of a left anterior thoracotomy, and cardiopulmonary bypass is used by way of peripheral cannulation. Exposure is enhanced by thoracoscopic instrumentation. The coronary circulation is not interrupted and visualization for anastomoses is accomplished by applying air pressure to the opened artery during hypothermic fibrillatory arrest. It should be observed that the anastomoses were done under direct vision using conventional instruments and suture technique and aided by fiberoptic illumination and, for the posterior descending branch right gastroepiploic artery anastomosis, perhaps by endoscopic visualization. I am not convinced that a left anterior thoracotomy, resection of the fourth rib cartilage, counterincisions for thoracoscopic instruments, and a left groin incision in their totality are any less invasive, less painful, or more cosmetically acceptable than a median sternotomy. Nor am I persuaded that mean operative, cardiopulmonary bypass duration, and postoperative length of stay times of 5.3 hours, 92 minutes, and 5.5 days, respectively, in young patients with one- or two-vessel disease and good left ventricular function represent a simplification in intraoperative and postoperative care compared with conventional management. Let us welcome innovation and the contributions exemplified by the report by Lin and colleagues. At the same time, we must demand studies directly comparing the new operations with the standard operation before we give our patients and the public the impression that something new and perhaps less invasive is as safe as standard coronary artery bypass grafting as performed today and is associated with the same well-documented excellent long-term benefits. Daniel J. Ullyot, MD 1828 El Camino Real Suite 802 Burlingame, CA by The Society of Thoracic Surgeons /97/$17.00 Published by Elsevier Science Inc PII S (97)