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

This Article Abstract Full Text (PDF) 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): Mudassir I. Dar Franco Ciulli Graham J. Cooper Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Dar, M. I. Articles by Cooper, G. J. Search for Related Content PubMed PubMed Citation Articles by Dar, M. I. Articles by Cooper, G. J. Related Collections Coronary disease Myocardial protection

Ann Thorac Surg 2001;71:794-796
© 2001 The Society of Thoracic Surgeons

---

Original article: cardiovascular

Single aortic cross-clamp technique reduces S-100 release after coronary artery surgery

^a Department of Cardiothoracic Surgery, Northern General Hospital, Sheffield, United Kingdom

Accepted for publication April 25, 2000.

Address reprint requests to Dr Cooper, Sheffield Cardio-Thoracic Unit, Northern General Hospital, Sheffield, S5 7AU, UK
e-mail: graham.cooper{at}northngh-tr.trent.nhs.uk

	Abstract

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
Background. Neurologic impairment after coronary artery bypass grafting is associated with cerebral embolization. An important cause of embolism is aortic manipulation. Constructing both distal and proximal anastomoses during a single period of aortic cross-clamping avoids this source of embolism and may reduce neurologic injury after coronary artery bypass grafting.

Methods. Fifty consecutive patients undergoing coronary artery bypass grafting were prospectively randomized to group 1, in which a single aortic cross-clamping was used to construct distal and proximal anastomoses, or to group 2, in which the proximal anastomoses were each constructed with a partial occluding aortic clamp. Levels of S-100 and troponin-T release were measured preoperatively and postoperatively.

Results. Aortic cross-clamp time was significantly longer in group 1, but other preoperative and intraoperative variables were equally represented in both groups. Control group levels of S-100 and troponin-T were similar. Postoperative S-100 levels were significantly higher in group 2 than in group 1 (p < 0.015). No significant difference was found between the groups in postoperative troponin-T levels.

Conclusions. The results of this trial suggest improved cerebral protection is associated with the single aortic cross-clamp technique for coronary artery bypass grafting with no increase in myocardial damage. The single aortic cross-clamp technique is simple and inexpensive. We recommend its wider use.

	Introduction

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
Stroke and cognitive impairment after coronary artery bypass grafting are associated with cerebral embolization [1]. An important cause of embolism is manipulation of the ascending aorta [2]. Application and release of a partial occluding clamp to construct proximal anastomoses of saphenous vein grafts are associated with 28% of the total embolic events during bypass [3]. Constructing both distal and proximal anastomoses during a single period of aortic cross clamping avoids this source of embolism and may reduce neurologic injury after coronary artery bypass.

We have, therefore, compared two techniques—partial occluding clamp for proximal anastomoses construction and a single aortic cross-clamping period—in a prospective, randomized trial. Neurologic injury was assessed by measuring S-100 protein release. Increased S-100 release is associated with increased cerebral embolization [4] and clinically evident neurologic injury [5]. As the single cross-clamp technique lengthens the aortic cross-clamp time, myocardial damage was assessed by measuring troponin-T release.

	Material and methods

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
Fifty consecutive patients undergoing elective, isolated, primary CABG were prospectively randomized into two groups. In group 1, a single period of aortic cross-clamping was used to construct distal and proximal anastomoses. In group 2, the cross-clamp was removed after construction of the distal anastomoses and the proximal anastomoses were each constructed with a partial occluding aortic clamp.

Patients with history of cerebrovascular disease, carotid bruit, aortic calcification, atrial fibrillation, or age more than 75 years were excluded from the study. Operations were either performed by or directly supervised by one of two consultant surgeons (FC and GJC). Anesthetic, cardiopulmonary bypass, and myocardial protection techniques were standardized. The bypass circuit used a hollow-fiber membrane oxygenator, nonpulsatile flow generated by a roller pump, and 40 µm arterial line filter (Pall Biomedical, Portsmouth, UK). Flow was 2.4 L. min/m² at 37°C falling to 1.8 L. min/m² at 32°C. Arterial pressure was maintained between 50 and 70 mm Hg, hematocrit between 0.20 and 0.25, and alpha stat blood gas management was used. Cold blood cardioplegia was given both antegradely and retrogradely every 20 minutes with a terminal dose of warm blood cardioplegia given retrogradely immediately before release of the aortic cross-clamp.

Measurements of S-100 protein and troponin T were obtained with commercially available assays (Sangtec 100; Sangtec Medical AB, Bromma, Sweden). Control samples were taken immediately before induction of anesthesia, and subsequent samples were taken 20 minutes following cardiopulmonary bypass to determine S-100 levels and 12 hours postoperatively to determine troponin T levels.

Ethical committee approval was obtained, and all patients gave written informed consent.

Data are presented as median and interquartile range, and statistical comparisons are by ² and Mann Whitney tests with a probability of less than 0.05 considered significant.

	Results

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
One patient in group 2 was excluded because control S-100 levels were higher than postoperative. Each surgeon performed a similar number of cases in each group. Aortic cross-clamp time was significantly longer in group 1, but other preoperative and intraoperative variables were equally represented in both groups (Table 1). Control levels of S-100 and troponin T were similar. Postoperative S-100 levels were significantly higher in group 2 than in group 1. Mean measurements were 0.98 µg/L, (interquartile range [IQR], 0.61 to 1.11 µg/L) compared with 0.67 µg/L, (IQR, 0.40 to 0.84 µg/L), respectively, producing a p value less than 0.015 (Fig 1). No significant difference was found in the postoperative troponin T levels; in group 1, the mean measurement was 0.62 µg/L, (IQR 0.3 to 1.09 µg/L) and in group 2, 0.50 µg/L (IQR 0.35 to 1.09 µg/L) (Fig 1). No patient suffered a stroke or had clinically evident cognitive dysfunction.

View larger version (11K): [in this window] [in a new window]   Fig 1. Box and whisker plot showing postoperative markers. (A) S-100 levels. (B) Troponin-T levels. The box indicates interquartile range (IQR), and the bar shows the median; whiskers are 1.5 x IQR. O indicates an outlier more than 1.5 x IQR; * indicates an outlier more than 3.0 x IQR, # p < 0.015, group 1 versus group 2.

	Comment

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

We used S-100 release as a marker for cerebral injury. Release of S-100 is a recognized marker for neurologic injury [6–9], and peak concentrations are found in the serum at the termination of cardiopulmonary bypass [6, 10].The amount of S-100 release is related to the number of cerebral emboli [4] and the amount of cerebral damage [11]. There is a direct relationship between the number of cerebral emboli and the likelihood of neurologic complication [5, 12]. Application and release of a partial occluding clamp is associated with 28% of the total embolic load on bypass, whereas application and removal of the cross-clamp accounts for only 9.6% [3]. Although we have not shown cause and effect, the reduced embolic load associated with the single-clamp technique is a plausible explanation for the associated reduction in S-100 release and, by implication, cerebral damage.

In nonrandomized studies others have found evidence to suggest a neuroprotective effect of the single cross-clamp technique. Aranki and colleagues report a 0.6% incidence of stoke with a single-clamp technique and a 2% incidence with the conventional technique, although this difference is not statistically significant [13]. The Cleveland Clinic has reported a stroke rate of 0.7% in patients in whom the single clamp technique was used [14].

Technical developments that improve outcome after coronary artery bypass are rarely simple and inexpensive. The single aortic cross-clamp technique is both. We recommend its wider use.

	Acknowledgments

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
This work was supported by a grant from the Cardiothoracic Research Fund of the Northern General Hospital, Sheffield, UK. The troponin T assays were performed by Dr Paul O. Collinson, Department of Clinical Pathology, Mayday Healthcare NHS Trust, Thornton Heath, Surrey, United Kingdom.

	References

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 

1. Hammon J.W., Stump D.A., Kon N.D., et al. Risk factors and solutions for the development of neurobehavioral changes after coronary artery bypass grafting. Ann Thorac Surg 1997;63:1613-1618.[Abstract/Free Full Text]
2. Blauth C.I. Macroemboli and microemboli during cardiopulmonary bypass. Ann Thorac Surg 1995;59:1300-1303.[Abstract/Free Full Text]
3. Mills S.A. Cerebral injury and cardiac operations. Ann Thorac Surg 1993;56:S86-S91.
4. Grocott H.P., Croughwell N.D., Amory D.W., White W.D., Kirchner J.L., Newman M.F. Cerebral emboli and serum S100ß during cardiac operations. Ann Thorac Surg 1998;65:1645-1650.[Abstract/Free Full Text]
5. Clark R.E., Brillman J., Davis D.A., Lovell M.R., Price T.R.P., Magovern G.J. Microemboli during coronary artery bypass grafting. Genesis and effect on outcome. J Thorac Cardiovasc Surg 1995;109:249-258.[Abstract/Free Full Text]
6. Aberg T. Signs of brain cell injury during open heart operations: past and present. Ann Thorac Surg 1995;59:1312-1315.[Abstract/Free Full Text]
7. Westaby S., Johnsson P., Parry A.J., et al. Serum S100 protein. A potential marker for cerebral events during cardiopulmonary bypass. Ann Thorac Surg 1996;61:88-92.[Abstract/Free Full Text]
8. Kumar P., Dhital K., Hossein-Nia M., Patel S., Holt D., Treasure T. S-100 protein release in a range of cardiothoracic surgical procedures. J Thorac Cardiovasc Surg 1997;113:953-954.[Free Full Text]
9. Johnsson P, Lundqvist C, Lindgren A, Ferencz I, Alling C, Stahl E. Cerebral complications after cardiac surgery assessed by S-100 and NSE levels in blood. J Cardiovas Anesth 1995;9:694–70.
10. Taggart D.P., Mazel J.W., Bhattacharya K., et al. Comparison of serum S-100ß levels during CABG and intracardiac operations. Ann Thorac Surg 1997;63:492-496.[Abstract/Free Full Text]
11. Missler U., Wiesmann M., Friedrich C., Kaps M. S-100 protein and neuron-specific enolase concentrations in blood as indicators of infarction volume and prognosis in acute ischemic stroke. Stroke 1997;28:1956-1960.[Abstract/Free Full Text]
12. Stump D.A., Tegeler C.H., Rogers A.T., et al. Neuropsychological deficits are associated with the number of emboli detected during cardiac surgery. Stroke 1993;24:509.
13. Aranki S.F., Rizzo R.J., Adams D.H., et al. Single-clamp technique. An important adjunct to myocardial and cerebral protection in coronary operations. Ann Thorac Surg 1994;58:296-303.[Abstract]
14. Loop F.D., Higgins T.L., Panda R., Pearce G., Estafanous F.G. Myocardial protection during cardiac operations. Decreased morbidity and lower cost with blood cardioplegia and coronary sinus perfusion. J Thorac Cardiovasc Surg 1992;104:608-618.[Abstract]

This article has been cited by other articles:

				S. G. Raja, M. Navaratnarajah, N. Fida, and C. S. Kitchlu For patients undergoing coronary artery bypass grafting at higher risk of stroke is the single cross-clamp technique of benefit in reducing the incidence of stroke? Interactive CardioVascular and Thoracic Surgery, June 1, 2008; 7(3): 500 - 503. [Abstract] [Full Text] [PDF]

				F. Capuano, C. Simon, A. Roscitano, G. Sclafani, E. Tonelli, and R. Sinatra Cardiac Troponin I Concentrations During On-Pump Coronary Artery Surgery Asian Cardiovasc Thorac Ann, December 1, 2007; 15(6): 502 - 506. [Abstract] [Full Text] [PDF]

				M. Caputo, P. Narayan, and G. D. Angelini Conventional surgery with aortic cross-clamping MMCTS, March 15, 2006; 2006(0315): 828. [Abstract] [Full Text] [PDF]

				M. A. Grega, L. M. Borowicz, and W. A. Baumgartner Impact of single clamp versus double clamp technique on neurologic outcome Ann. Thorac. Surg., May 1, 2003; 75(5): 1387 - 1391. [Abstract] [Full Text] [PDF]

				Y. J. Woo and T. J. Gardner Myocardial Revascularization with Cardiopulmonary Bypass Card. Surg. Adult, January 1, 2003; 2(2003): 581 - 607. [Full Text]

				J. L. Januzzi Jr, K. Lewandrowski, T. E. MacGillivray, J. B. Newell, S. Kathiresan, S. J. Servoss, and E. Lee-Lewandrowski A comparison of cardiac troponin T and creatine kinase-MB for patient evaluation after cardiac surgery J. Am. Coll. Cardiol., May 1, 2002; 39(9): 1518 - 1523. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) 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): Mudassir I. Dar Franco Ciulli Graham J. Cooper Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Dar, M. I. Articles by Cooper, G. J. Search for Related Content PubMed PubMed Citation Articles by Dar, M. I. Articles by Cooper, G. J. Related Collections Coronary disease Myocardial protection