HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Geir Tangen Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Øvrum, E. Articles by Holen, E. A. Search for Related Content PubMed PubMed Citation Articles by Øvrum, E. Articles by Holen, E. A.

Ann Thorac Surg 1997;64:159-162
© 1997 The Society of Thoracic Surgeons

---

Original Articles: Cardiovascular

Facing the Era of Minimally Invasive Coronary Grafting: Current Results of Conventional Bypass Grafting for Single-Vessel Disease

Oslo Heart Center, Oslo, Norway

Accepted for publication January 23, 1997.

	Abstract

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 
Background. The concepts of minimally invasive coronary artery bypass grafting have gained increasing attention and interest from cardiac surgeons. Operations through small incisions are mostly applied to patients with less extensive coronary disease, mostly single-vessel disease. The aim of this study was to identify a baseline level of conventional coronary bypass grafting for this group of patients, particularly with regard to surgical complications and immediate results.

Methods. Of 3,637 consecutive patients undergoing coronary artery bypass grafting during the period 1989 to 1995, 99 patients (2.7%) were identified to have single-vessel disease. The preoperative and hospital data of this subset of patients were analyzed.

Results. The left internal mammary artery was grafted in 96% of the patients, either as single graft to the left anterior descending artery or sequentially to the left anterior descending artery and a diagonal branch. Additional vein grafts were placed in 36 patients, and the mean number of distal anastomoses was 1.6 ± 0.6. Mean ischemic time and cardiopulmonary bypass time were 15.3 ± 9.6 minutes and 29.0 ± 12.5 minutes, respectively. The patients were weaned from the ventilator 1.5 ± 0.8 hours postoperatively, and all patients were out of bed the morning after the operation. No patients required homologous blood or plasma transfusions. The morbidity rate was low, and all patients survived.

Conclusions. For this highly selected group of patients, coronary artery bypass grafting based on median sternotomy, cardiopulmonary bypass, and cardioplegic arrest carries a very high rate of immediate success. Such data may be useful as a baseline when considering the costs and benefits of new surgical procedures.

	Introduction

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 
Over a short period of time, various techniques for minimally invasive coronary artery bypass grafting have gained growing attention from cardiac surgeons [1–4]. For less extensive coronary disease, mostly single-vessel disease, new surgical procedures have been introduced, including dissection of the internal mammary arteries through small incisions, with or without the use of a videoscope, and with or without cardiopulmonary bypass (CPB) when suturing the anastomosis. However, when we are facing novel techniques that include new surgical challenges and learning curves, we must define a current baseline with regard to common incidences of complications and operative technical failures. The aim of this study was to analyze the present results in patients with single-vessel disease undergoing conventional coronary bypass procedures using median sternotomy, extracorporeal circulation, and cardioplegic arrest.

	Material and Methods

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 
During the 7-year period from 1989 through 1995, 3,637 consecutive patients underwent coronary artery bypass procedures in our clinic. Ninety-nine patients (2.7%) were identified to have single-vessel disease only, without valvular disease or significant ventricular aneurysms. The preoperative and in-hospital parameters of this subset of patients were analyzed.

All patients in the study group were first-time candidates for operation, and the indications were restenosis after percutaneous transluminal coronary angioplasty or lesions inaccessible by percutaneous transluminal coronary angioplasty. As one third of the operations in our department are currently performed by external cardiac surgeons, altogether 14 operators were involved. Demographic data of the patients are presented in Table 1 and reflect a somewhat younger age and lower incidence of diabetes mellitus compared with a more typical group of patients with multivessel disease. Emergency cases after failed angioplasty and patients with significant preoperative renal failure were referred to a neighboring department and are therefore not a part of the present series.

The anesthesia protocol was designed to permit early extubation and included a combination of diazepam (0 to 0.2 mg/kg), midazolam hydrochloride (0 to 0.2 mg/kg), fentanyl (6 to 8 µg/kg), and pancuronium bromide, supplemented with isoflurane and nitrous oxide.

Blood Conservation
Blood conservation before and after the operation has previously been described in detail [5], and included removal of autologous blood before bypass for retransfusion after bypass, intraoperative and postoperative retransfusion of the oxygenator and circuit contents (without any cell processing), and postoperative autotransfusion of shed mediastinal blood up to 18 hours postoperatively. If possible, administration of platelet inhibitors like aspirin was discontinued 7 days preoperatively. Normovolemic anemia was accepted to a hematocrit of 25%, which represented a level of consideration for homologous red cell transfusion.

Hemoglobin concentration and hematocrit were recorded preoperatively, 3 hours and 18 hours postoperatively, and at discharge. All patient and laboratory data were registered prospectively and stored in a computer data base.

	Results

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 
Most patients were in New York Heart Association functional class III or IV. At the operation, the left internal mammary artery was used in 95 of the 99 patients, either as a single graft to the left anterior descending artery (86 patients) or sequentially to the left anterior descending artery and a diagonal branch (9 patients). Additional saphenous vein grafts, including 8 sequential grafts, were placed in 36 patients. The right mammary artery was anastomosed to the right coronary artery in 1 patient. Three patients received saphenous vein grafts only, partly due to the surgeon's preference, and partly because of left internal mammary artery pathology (arteritis and dissection). The mean number of distal anastomoses was 1.6 ± 0.7. The average ischemic time was relatively short (15.3 ± 9.6 minutes), and the mean extracorporeal circulation time was less than half an hour (29.0 ± 12.5 minutes). There were no returns to the operating theater for technical errors. One patient was reexplored for postoperative bleeding. The patients were weaned from the ventilator 1.5 ± 0.8 hours postoperatively, and all patients were able to move outside the bed the morning after the operation. Length of hospital stay was more dependent on local medical infrastructure than medical indications, and could not be used to monitor physical progress. However, within the fifth postoperative day, 96 of the 99 patients were physically rehabilitated in terms of walking stairs or freely outside the hospital. No patients received homologous blood or plasma transfusions during the hospital stay, and the mean hemoglobin concentration at discharge was 126 ± 13 g/L. The mean hemoglobin concentration before the operation was 146 ± 12 g/L.

The morbidity rate was low (Table 2), including superficial wound infections in 2 patients, 1 perioperative myocardial infarction, and 1 urinary tract infection. There were no incidence of deep infections, and persistant neurologic disorders were not seen. All patients survived. During the time period under investigation, no patients have had a redo operation, but a complete follow-up has not been undertaken.

	Comment

Top Footnotes Abstract Introduction Material and Methods Results Comment References

During the relatively short time of follow-up, no redo operations have been necessary so far. This is in agreement with others [7], who were able to demonstrate a very low incidence of reintervention during the first 5 years after coronary artery bypass grafting for single-vessel disease.

However, despite the widespread clinical success and reliability of CPB, extracorporeal circuits expose blood to shear stresses and to contact with large areas of synthetic, nonendothelial surfaces. This results in mechanical damage to blood components and activation of biological cascades, which may contribute to development of a generalized inflammatory response and organ dysfunction [8, 9]. Although most patients obviously tolerate CPB very well, uncertainty still exists concerning brain dysfunction after extracorporeal circulation. Westaby and associates [10] recently demonstrated release of the protein S100 after CPB. This protein is usually found in high concentrations in glial and Schwann cells, and may be a marker of cerebral impairment.

Both to reduce the side effects of CPB and to lower the costs, "off-pump" operations have been applied in selected patients having coronary artery bypass grafting through a median sternotomy [11, 12]. This approach, however, is limited by the accuracy of the anastomoses to be performed while the heart is beating. Further, the posterior part of the heart is difficult to reach for revascularization. This technique is also reported to reduce bleeding and bank blood requirement [11]. In the present study, however, a simple retransfusion protocol could avoid transfusions of any homologous blood products in all patients. Neither was postoperative bleeding a problem after the short CPB time required for this selected group of patients.

More than 30 years have passed since Kolessov [13] performed the first direct anastomosis between the internal mammary artery and a coronary vessel without the assistance of CPB, and since then, continuous development and sophistication of extracorporeal circulation and myocardial protection have been implemented to create an optimal field for cardiac operations. A general improvement of oxygenators and all CPB equipment has taken place, and recently, the use of heparin-coated extracorporeal circuits has been shown to ameliorate the deleterious effects of CPB [14, 15]. Less activation of complement and granulocytes has been demonstrated [15], and even decreased release of the protein S100 [16]. In this context, efforts should certainly be made to shorten the extracorporeal time as much as possible to reduce blood activation and cell trauma.

Inspired by the less invasive videoscopic techniques used for laparoscopic procedures and thoracoscopic operations, coronary artery bypass grafting through small incisions has gained popularity [1–4,17]. The left internal mammary artery graft is prepared in situ by dissection under direct vision or with use of a videoscope [1, 2]. The actual coronary anastomosis, most often to the left anterior descending artery, is typically performed through a limited lateral anterior thoracotomy. The operations are carried out with or without CPB. To achive a bloodless field, snaring sutures or tourniquets are placed around the target vessel on both sides of the anastomosis. The postoperative scar is limited, and the in-hospital stay has been short [1]. However, these techniques are obviously more challenging than a situation of arrested heart and a dry field. Also in the hands of experienced surgeons, some technical failures have been reported [2, 3], which required early redo operations. This is certainly a matter of concern, as a very low incidence of technical errors can be accepted, particularly when considering the dependence on a patent internal mammary artery-to-left anterior descending artery anastomosis for a successful long-term prognosis [18]. Concerns have also been raised because of later stenosis at the sites of the snaring sutures placed around the coronary arteries [19]. Similar technical problems are present when using supporting pumps like the Hemopump, while the anastomoses still have to be performed on beating heart [20].

The present results of coronary artery bypass grafting for single-vessel disease with the aid of CPB and cardioplegic arrest are nearly optimal in terms of immediate results. This fact cannot be neglected when exploring alternative techniques. However, minimally invasive operations and "off-pump" coronary artery bypass grafting have come to stay, and may be a step forward for selected patients, particularly as an alternative to percutaneous intraluminal interventions. Nevertheless, the high standards of today's coronary artery surgery require intensive training, as well as optimizing the surgical instruments, before these techniques are introduced into routine clinical practice. Small incisions are obviously more cosmetically attractive and may be less painful, but smaller scars or shorter hospital stay can never justify suboptimal myocardial revascularization. Therefore, when we have passed the initial learning curve, prospectively randomized studies are needed to prove the value of less invasive coronary operations. So far, the present "state of the art" of conventional CPB coronary bypass grafting has to serve as a guideline for future progress.

	Footnotes

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 
Address reprint requests to Dr Øvrum, Oslo Heart Center, Pilestredet 32, 0027 Oslo, Norway.

	References

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 

1. Benetti FJ, Ballester C, Sani G, Boonstra P, Grandjean J. Video assisted coronary bypass surgery. J Card Surg1995;10:620–5.[Medline]
2. Nataf P, Lima L, Regan M, et al. Minimally invasive coronary surgery with thoracoscopic internal mammary artery dissection: surgical technique. J Card Surg1996;11:288–92.[Medline]
3. Calafiore AM, Di Giammarco G, Teodori G, et al. Left anterior descending coronary artery grafting via left anterior small thoracotomy without cardiopulmonary bypass. Ann Thorac Surg1996;61:1658–65.[Abstract/Free Full Text]
4. Robinson MC, Gross DR, Zeman W, Stedje-Larsen E. Minimally invasive coronary artery bypass grafting: a new method using an anterior mediastinotomy. J Cardiac Surg1995;10:529–36.[Medline]
5. Øvrum E, Åm Holen E, Tangen G. Consistent non-pharmacologic blood conservation in primary and reoperative coronary artery bypass grafting. Eur J Cardiothorac Surg1995;9:30–5.[Abstract]
6. Clark RE. The Society of Thoracic Surgeons National Database status report. Ann Thorac Surg1994;57:20–6.[Abstract]
7. Boylan MJ, Lytle BW, Loop FD, et al. Surgical treatment of isolated left anterior descending coronary stenosis. Comparison of left internal mammary artery and venous autograft at 18 to 20 years follow-up. J Thorac Cardiovasc Surg1994;107:657–62.[Abstract/Free Full Text]
8. Kirklin JK, Westaby S, Blackstone EH, Kirklin JW, Chenoweth DE, Pacifico AD. Complement and the damaging effects of cardiopulmonary bypass. J Thorac Cardiovasc Surg1983;86:845–57.[Abstract]
9. Van Oeveren W, Kazatchine MD, Descamps-Latscha B, et al. Deleterious effects of cardiopulmonary bypass. A prospective study of bubble versus membrane oxygenation. J Thorac Cardiovasc Surg1985;89:888–99.[Abstract]
10. Westaby S, Johnsson P, Parry AJ, et al. Serum S100 protein: a potential marker for cerebral events during cardiopulmonary bypass. Ann Thorac Surg1996;61:88–92.[Abstract/Free Full Text]
11. Pfister AJ, Zaki MS, Garcia JM, et al. Coronary artery bypass without cardiopulmonary bypass. Ann Thorac Surg1992;54:1085–92.[Abstract]
12. Buffolo E, de Andrade JCS, Branco JNR, et al. Coronary artery bypass grafting without cardiopulmonary bypass. Ann Thorac Surg1996;61:63–6.[Abstract/Free Full Text]
13. Kolessov VI. Mammary artery–coronary artery anastomosis as method of treatment for angina pectoris. J Thorac Cardiovasc Surg1967;54:535–44.[Medline]
14. Gu YJ, van Oeveren W, Akkerman C, Boonstra PW, Huyzen RJ, Wildevuur CRH. Heparin-coated circuits reduce the inflammatory response to cardiopulmonary bypass. Ann Thorac Surg1993;55:917–22.[Abstract]
15. Øvrum E, Mollnes TE, Fosse E, et al. Complement and granulocyte activation in two different types of heparinized extracorporeal circuits. J Thorac Cardiovasc Surg1995;110:1623–32.[Abstract/Free Full Text]
16. Svenmarker S, Sandstrøm E, Karlsson T, Häggmark S, Åberg T. Clinical effects of the heparin coated surface in cardiopulmonary bypass. Eur J Cardiothorac Surg (in press).
17. Arom KV, Emery RW, Nicoloff DM. Ministernotomy for coronary artery bypass grafting. Ann Thorac Surg 1996;61:1271–2.[Abstract/Free Full Text]
18. Cameron A, Davis KB, Green G, Schaff HV. Coronary bypass surgery with internal-thoracic-artery grafts-effects on survival over a 15-year period. N Engl J Med 1996;334:216–9.[Abstract/Free Full Text]
19. Gundry SR. Discussion of: Pfister AJ, Zaki MS, Garcia JM, et al. Coronary artery bypass without cardiopulmonary by- pass. Ann Thorac Surg 1992;54:1085–92.
20. Lönn U, Peterzèn B, Granfeldt H, Casimir-Ahn H. Coronary artery operations with the support of the Hemopump cardiac assist system. Ann Thorac Surg 1994;58:519–23.[Abstract]

This article has been cited by other articles:

				T. M. McLoitghlin JR Complications of Minimally Invasive Cardiac Surgical Procedures Seminars in Cardiothoracic and Vascular Anesthesia, July 1, 1999; 3(2): 136 - 142. [Abstract] [PDF]

				E. W. L. Jansen, C. Borst, J. R. Lahpor, P. F. Grundeman, F. D. Eefting, A. Nierich, E. O. Robles de Medina, and J. J. Bredee Coronary artery bypass grafting without cardiopulmonary bypass using the octopus method: results in the first one hundred patients J. Thorac. Cardiovasc. Surg., July 1, 1998; 116(1): 60 - 67. [Abstract] [Full Text]

This Article Abstract Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Geir Tangen Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Øvrum, E. Articles by Holen, E. A. Search for Related Content PubMed PubMed Citation Articles by Øvrum, E. Articles by Holen, E. A.