01 сентября 2001 00:00 |
Effect of topical vasodilators on gastroepiploic artery graft
Background . Mobilization of the gastroepiploic artery (GEA) often results in a vasospasm with reduction of early graft flow. In order to prevent or suppress this highly reactive artery's spasm, we have compared the effect of 4 vasodilators, used in external application to prepare the GEA graft, prior to myocardial revascularization.
Methods . We performed
Results . A significant increase in free flow occurred in all groups except for the normal saline solution group with measurements from 26.1 ± 3.6 mL/min to 26.4 ± 6.5 mL/min; p = 0.9. The most important increase in flow before and after local application occurred with glyceryl trinitrate and papaverine: from 25.5 ± 2 mL/min to 50 ± 6.1 mL/min ( p 0.01) and from 36.8 ± 3.2 mL/min to 62 ± 7.8 mL/min ( p < 0.01) respectively. Nicardipine and linsidomine produced a less significant increase in flow: from 33.1 ± 3.6 mL/min to 47.7 ± 8.9 mL/min ( p < 0.05) and from 28 ± 3.8 mL/min to 39.8 ± 7.5 mL/min ( p < 0.05) respectively. When comparing percentage of flow increase, glyceryl trinitrate appeared to be significantly more efficient than nicardipine and linsidomine ( p < 0.01 versus both groups). Although papaverine was more efficient than nicardipine and linsidomine, it did not reach statistical significance.
Conclusions . During intraoperative preparation of the GEA graft, glyceryl trinitrate and papaverine to a lesser extent, used as topical vasodilators, appear to be more efficient in external application to increase the free flow of the GEA.
The superiority of arterial grafts for myocardial revascularization, based on their
Patients and methods
We studied 50 consecutive patients undergoing elective coronary artery bypass operation from October 1996 to December 1997. The protocol was approved in January 1996 by the local institutional human research committee, at the Michallon Hospital in Grenoble. Criteria for admission into the study group were elective coronary artery bypass operation using the GEA. All patients received nitrates, calcium antagonist,
Topical solutions: All topical solutions were at room temperature (18°C) when applied:
1.Group 1: papaverine 80 mg in 10 mL of 0.9% sodium chloride solution (Aguettant, Lyon, France); 2.Group 2: nicardipine 10 mg in 10 mL of 0.9% sodium chloride solution (Novartis,
Ten minutes after the first measurement, the GEA was unwrapped and the bulldog clamp was taken off. The second GEA flow measurement was obtained and hemodynamic data were recorded again. To ensure that the experiment
Each patient served as his or her own control. All values were expressed as mean ± standard error. The significance of the changes in GEA flow and hemodynamic data was tested
There was no statistically significant difference among each of the 5 groups concerning sex ratio and age ( [Table 1] ).
Hemodynamic data (heart rate, central venous pressure, mean arterial pressure), at the time of the first and second flow measurements, was not significantly different either ( [Table 2] ).
Mean flow for the first and second measurement, for each group, is shown in . [Table 3] There was no significant difference among the first flow measurements in the 5 groups. Normal saline solution produced no increase in flow before and after local application, whereas the most effective increase in flow occurred with papaverine and glyceryl trinitrate ( p p p
In the present study, glyceryl trinitrate and papaverine to a lesser extent, appear to be more efficient than nicardipine and linsidomine as topical vasodilators on GEA flow. Indeed, GEA is a highly vasoactive artery, which is prone to spasm because of its muscular histological status   and the method of preparation of the GEA graft appears to be the major determinant of GEA total flow capacity  . The decrease in diameter results in lesser arterial flow, with possible clinical consequences such as functional insufficiency. In vitro comparative study between ITA and GEA showed stronger contraction for the GEA to vasoconstrictors   . If clinical evaluation of vasodilators used for the preparation of the ITA is now well documented, with controversial results as to which topical vasodilator better relieves intraoperative spasm of the ITA graft   , to our knowledge, there are no formal studies testing other topical vasodilators such as papaverine, available for GEA graft preparation.
Free flow of the GEA depends both on the perfusion pressure and the vasomotor properties of the graft. This is the reason why measuring it is a good method to compare the effect of topical vasodilators. In this study, the time (10 minutes) between the 2 measurements may have underestimated their maximal effect. But, a quick response is essential with regard to operative time and for ethical reasons. We chose to perform an external administration of these treatments since intraluminal administration of papaverine has been shown to induce detrimental effects on the ITA wall  , or direct mechanical trauma  . Furthermore, chemical damage due to the acidity of some solutions (papaverine, nicardipine) could have been detrimental to the endothelium. Proximal placement of the clamp on the pedicle was performed because we only wanted to assess the drug's chemical effect. Indeed, distal placement of the bulldog could have been more efficient in promoting maximal dilation of the conduct. This would be due to the vasodilator and to a mechanical effect induced by exposure to arterial pressure.
The results of the present study confirm that the GEA is in spasm, with reduced flow, immediately after mobilization as shown in previous studies  . The fact that normal saline solution did not increase the flow shows that the vessel does not undergo substantial spontaneous relaxation in the time between end of mobilization and start of cardiopulmonary bypass, as demonstrated by our pilot study. The 5 groups are homogeneous, and, according to clinical data, the hemodynamic status is comparable between the 2 measurements. This suggests that for the vasodilator concentration used, there was no significant absorption through the surrounding soft tissues resulting in a systemic blood pressure drop. We performed aortic and right atrial cannulation before the first measurement because these maneuvers may be associated with important blood volume loss, leading to variation in GEA flow as previously noted in ITA flow measurement  .
Nicardipine and linsidomine produced a similar increase in GEA flow, but were both less potent than papaverine and glyceryl trinitrate. Papaverine, a lipophilic vasodilator used to prepare the ITA, is the classical agent to protect against GEA spasm, although no clinical study has compared other topical vasodilators. All human studies concerning the effect of vasodilators in the GEA where carried out in vitro, mainly in GEA rings precontracted with various vasoconstrictors
In conclusion, our study shows that in order to prevent or reverse the intraoperative spasm of the GEA graft in myocardial revascularization, our preference goes to glyceryl trinitrate or papaverine topical vasodilators. Furthermore, the possibility of administering a low dose of glyceryl trinitrate intravenously should be taken in consideration, and further clinical studies are required to determine the effect of systemic glyceryl trinitrate infusion on GEA flow, as previously demonstrated for ITA graft  .
1.Dion R., Etienne P.Y., Verhelst R.. Bilateral mammary grafting. Clinical functional and angiographic assessment in 400 consecutive patients. Eur J Cardiothorac Surg 1993;7:287−294.
2.Cameron A., Davis K.B., Green G., Schaff H.V.. Coronary bypass surgery
3.Pym J., Brown P.M., Charrette E.J.P., Parker J.O., West R.O..
4.Suma H., Fukumoto H., Takeuchi A.. Coronary artery bypass grafting by utilizing in situ right gastroepiploic artery. Ann Thorac Surg 1987;44:394−397.
5.Suma H., Wanibuchi Y., Futura S., Isshiki T., Yamaguchi T., Takanashi R.. Comparative study between the gastroepiploic and the internal thoracic artery as a coronary bypass graft. Size, flow, patency, histology. Eur J Cardiothorac Surg 1991;5:244−247.
6.Suma H., Takanashi R.. Arteriosclerosis of the gastroepiploic and internal thoracic arteries. Ann Thorac Surg 1990;50:413−416.
7.Grandjean J.G., Boonstra P.W., Heyer P.D., Ebels T.. Arterial revascularization with the right gastroepiploic artery and internal mammary arteries in 300 patients. J Thorac Cardiovasc Surg 1994;107:1309−1316.
8.Jegaden O., Eker A., Montagna P.. Risk and results of bypass grafting using bilateral internal mammary and right gastroepiploic arteries. Ann Thorac Surg 1995;59:955−960.
9.Mills N.L., Bringaze W.L.. Preparation of the internal mammary artery graft. Which is the best method?. J Thorac Cardiovasc Surg 1989;98:73−79.
10.Cooper G.J., Wilkinson G.A.L., Angelini G.D.. Overcoming perioperative spasm of the internal mammary artery. J Thorac Cardiovasc Surg 1992;104:465−468.
11.Sasson L., Cohen A.J., Hauptman E., Schachner A.. Effect of topical vasodilators on internal mammary arteries. Ann Thorac Surg 1995;59:494−496.
12.Suma H.. Spasm of the right gastroepiploic artery. Ann Thorac Surg 1990;49:168−169.
13.He G.W., Yang C.Q.. Comparison among arterial grafts and coronary artery. An attempt at functional classification. J Thorac Cardiovasc Surg 1995;109:707−715.
14.Cracowski J.L., Chavanon O., Durand M.. Effect
15.Mills N.L., Hockmuth D.R., Everson C.T., Robart C.C.. Right gastroepiploic artery used for coronary artery bypass grafting. Evaluation of flow characteristics and size. J Thorac Cardiovasc Surg 1993;106:579−585.
16.Dignan R.J., Yeh T., Dyke C.M.. Reactivity of gastroepiploic and internal mammary arteries. Relevance to coronary artery bypass grafting. J Thorac Cardiovasc Surg 1992;103:116−122.
17.Van Son J.A.M., Tavilla G., Noyez L.. Detrimental sequelae on the wall of internal mammary artery caused by hydrostatic dilation with diluted papaverine solution. J Thorac Cardiovasc Surg 1992;104:972−976.
18.Dregelid E., Heldal K., Resch F., Stangeland L., Breivik K., Svendsen E.. Dilation of the internal mammary artery by external and intraluminal papaverine application. J Thorac Cardiovasc Surg 1995;110:697−703.
19.Von Segesser L.K., Lehmann K., Turina M.. Deleterious effects of shock in internal mammary artery anatomoses. Ann Thorac Surg 1989;47:575−579.
21.Ali A.T., Montgomery W.D., Santamore W.P., Spence P.A.. Preventing gastroepiploic artery spasm. J Surg Res 1997;71:41−48.
23.Bilgen F., Yapici M.F., Serbetcioglu A., Tarhan I.A., Coruh T., Цzler A.. Effect of normothermic papaverine to relieve intraoperative spasm of the internal thoracic artery. Ann Thorac Surg 1996;62:769−771.
24.Arnaudov D., Cohen A.J., Zabeeda D.. Effect of systemic vasodilators on internal mammary flow during coronary bypass grafting. Ann Thorac Surg 1996;62:1816−1819.
01 сентября 2001 | 00:09Individualized surgical strategy for the reduction of stroke risk in patients undergoing coronary artery bypass grafting
Individualized surgical strategy for the reduction of stroke risk in patients undergoing coronary artery bypass grafting
01 сентября 2001 | 00:09Myocardial revascularization with the left internal thoracic artery Y graft configuration
Myocardial revascularization with the left internal thoracic artery Y graft configuration
01 сентября 2001 | 00:09Procoagulant activity after off-pump coronary operation: is the current anticoagulation adequate?
Procoagulant activity after off-pump coronary operation: is the current anticoagulation adequate?
01 сентября 2001 | 00:09Reversed-J inferior sternotomy for beating heart coronary surgery
Reversed-J inferior sternotomy for beating heart coronary surgery
01 сентября 2001 | 00:09Management of porcelain aorta during coronary artery bypass grafting
Management of porcelain aorta during coronary artery bypass grafting