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Prevention of internal thoracic artery spasm
Prevention of Internal Thoracic Artery Spasm Anvay V. Mulay, MCh, K. Kesava Dev, MCh, and R. Unnikrishnan Nair, FRCS Department of Cardiothoracic Surgery, Killingbeck Hospital, Leeds, United Kingdom
Perioperative spasm of the internal thoracic artery is a common experience in coronary artery bypass grafting. We describe a simple method of harvesting the internal thoracic artery with improved ease of dissection that helps to prevent the arterial spasm. (Ann Thorac Surg 1997;64:564) © 1997 by The Society of Thoracic Surgeons
f o r m e d in large part b y electrocautery a n d occlusion of the major side b r a n c h e s with hemostatic clips. The artery is mobilized as a pedicle from the first intercostal space proximally to the bifurcation below. Direct h a n d l i n g of the artery is a v o i d e d as much as possible. The pedicle is left intact a n d d i v i d e d only at the time it is a n a s t o m o s e d to the coronary artery.
he superiority of the internal thoracic artery graft as conduit for m y o c a r d i a l revascularization is well established. However, s u b o p t i m a l flow due to s p a s m of this conduit in the early p o s t b y p a s s p e r i o d m a y be detrimental, particularly in cases of h y p e r t r o p h i e d m y o cardium, p o o r left ventricular function, a n d recent m y o cardial infarction [1]. Different m e t h o d s for relieving the s p a s m p r o d u c e d d u r i n g harvesting of the internal thoracic artery have b e e n described. Some of the techniques include use of vasodilators b y external application to the pedicle, infiltration in the pedicle, a n d intraluminal injection with or without hydrostatic dilation [1, 2]. Recently, the i m p o r tance of n o r m o t h e r m i a for the o p t i m u m action of p a p a v erine has b e e n e l u c i d a t e d [3]. John a n d associates [4] have d e s c r i b e d the injection of n o r m a l saline solution b e t w e e n the costal cartilages a n d adjacent tissue for s e p a r a t i n g the internal thoracic artery from the chest wall as a useful m e t h o d in r e d u c i n g surgical trauma. W e describe a simple t e c h n i q u e in which dilute p a p a v e r i n e in w a r m saline solution is injected into the endothoracic tissue a r o u n d the internal thoracic artery before the dissection is c o m m e n c e d .
Comment
T
Technique The exposure of the internal thoracic artery is achieved by an a p p r o p r i a t e retractor a n d positioning of the operating table. The p l e u r a is s e p a r a t e d from the chest wall a n d o p e n e d widely, if necessary, for a d e q u a t e exposure of the artery from the level of the subclavian vein above to the level of xiphoid cartilage below. Papaverine h y d r o chloride (McCarthy Lab, Romford, UK) diluted in w a r m 0.9% s o d i u m chloride solution (1.25 mg/mL; p H 4.9) is injected with a fine 24-gauge metal n e e d l e t h r o u g h the endothoracic fascia, a p p r o x i m a t e l y 4 to 5 m m away from the internal thoracic artery. The point of the n e e d l e is p l a c e d b e t w e e n the costal cartilage a n d the adjacent tissue, a n d in total about 10 to 15 mL of this solution is infiltrated at three or four sites along the entire length of the internal thoracic artery. The dissection is then perAccepted for publication Feb 12, 1997. Address reprint requests to Mr Nair, Department of Cardiothoracic Surgery,, KillingbeckHospital, York Rd, Leeds, UK LS146UQ. © 1997 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
The injection of p a p a v e r i n e in the internal thoracic artery b e d facilitates easy a n d m i n i m a l l y traumatic harvesting b y hydrodissection. As the solution is injected into the space by the d e s c r i b e d technique, the internal thoracic artery stands out from the chest wall. In addition, dilation of the artery a n d its b r a n c h e s due to p a p a v e r i n e helps easy visualization a n d division. This has h e l p e d to expedite the harvesting of the internal thoracic artery without causing t r a u m a a n d c o n s e q u e n t spasm. A significant reduction in the m a x i m u m contractile response of the internal thoracic artery after p a p a v e r i n e t r e a t m e n t has b e e n d e m o n s t r a t e d b y Hillier a n d associates [5]. In our technique, as p a p a v e r i n e is injected even before the dissection is started, it dilates the artery a n d makes it less prone to severe spasm at the time of harvesting. Second, the mechanism of action of papaverine on the smooth muscle involves the inhibition of enzymatic activity a n d is o p t i m u m at 37°C [3]. Thus, infiltration around the internal thoracic artery with papaverine at the beginning allows it to act at the body temperature until the full length of the pedicle has been mobilized. Finally, keeping the pedicle intact avoids bathing of the internal thoracic artery in topical ice-cold saline solution. This technique allows longer duration of action by p a p a v e r i n e on the internal thoracic artery, at n e a r b o d y t e m p e r a t u r e , b e f o r e , d u r i n g , a n d after h a r v e s t i n g , t h e r e b y p r e v e n t i n g or m i n i m i z i n g the arterial spasm.
References 1. Mills NL, Bringaze WL. Preparation of the internal mammary artery graft. Which is the best method? J Thorac Cardiovasc Surg 1989;98:73-9. 2. Cooper GJ, Wilkinson GAL, Angelini GD. Overcoming perioperative spasm of the internal mammary artery: which is the best vasodilator? J Thorac Cardiovasc Surg 1992;104:4657.8. 3. Bilgen F, Yaplcl MF, Serbet~io~lu A, Tarhan A, ~oruh T, Ozler A. Effect of normothermic papaverine to relieve intraoperative spasm of the internal thoracic artery. Ann Thorac Surg 1996;62:769-71. 4. John LCH, Edmondson SJ, Rees GM. Modified technique of internal mammary artery harvest. Ann Thorac Surg 1991;52: 157-8. 5. Hillier C, Watt PAC, Sp~ TJ, Thurston H. Contraction and relaxation of human internal mammary artery after intraluminal administration of papaverine. Ann Thorac Surg 1992;53:1033-7. 0003-4975/97[$17.00 PII S0003-4975(97)00291-9
Perioperative spasm of the internal thoracic artery is a common experience in coronary artery bypass grafting. We describe a simple method of harvesting the internal thoracic artery with improved ease of dissection that helps to prevent the arterial spasm. (Ann Thorac Surg 1997;64:564) © 1997 by The Society of Thoracic Surgeons
f o r m e d in large part b y electrocautery a n d occlusion of the major side b r a n c h e s with hemostatic clips. The artery is mobilized as a pedicle from the first intercostal space proximally to the bifurcation below. Direct h a n d l i n g of the artery is a v o i d e d as much as possible. The pedicle is left intact a n d d i v i d e d only at the time it is a n a s t o m o s e d to the coronary artery.
he superiority of the internal thoracic artery graft as conduit for m y o c a r d i a l revascularization is well established. However, s u b o p t i m a l flow due to s p a s m of this conduit in the early p o s t b y p a s s p e r i o d m a y be detrimental, particularly in cases of h y p e r t r o p h i e d m y o cardium, p o o r left ventricular function, a n d recent m y o cardial infarction [1]. Different m e t h o d s for relieving the s p a s m p r o d u c e d d u r i n g harvesting of the internal thoracic artery have b e e n described. Some of the techniques include use of vasodilators b y external application to the pedicle, infiltration in the pedicle, a n d intraluminal injection with or without hydrostatic dilation [1, 2]. Recently, the i m p o r tance of n o r m o t h e r m i a for the o p t i m u m action of p a p a v erine has b e e n e l u c i d a t e d [3]. John a n d associates [4] have d e s c r i b e d the injection of n o r m a l saline solution b e t w e e n the costal cartilages a n d adjacent tissue for s e p a r a t i n g the internal thoracic artery from the chest wall as a useful m e t h o d in r e d u c i n g surgical trauma. W e describe a simple t e c h n i q u e in which dilute p a p a v e r i n e in w a r m saline solution is injected into the endothoracic tissue a r o u n d the internal thoracic artery before the dissection is c o m m e n c e d .
Comment
T
Technique The exposure of the internal thoracic artery is achieved by an a p p r o p r i a t e retractor a n d positioning of the operating table. The p l e u r a is s e p a r a t e d from the chest wall a n d o p e n e d widely, if necessary, for a d e q u a t e exposure of the artery from the level of the subclavian vein above to the level of xiphoid cartilage below. Papaverine h y d r o chloride (McCarthy Lab, Romford, UK) diluted in w a r m 0.9% s o d i u m chloride solution (1.25 mg/mL; p H 4.9) is injected with a fine 24-gauge metal n e e d l e t h r o u g h the endothoracic fascia, a p p r o x i m a t e l y 4 to 5 m m away from the internal thoracic artery. The point of the n e e d l e is p l a c e d b e t w e e n the costal cartilage a n d the adjacent tissue, a n d in total about 10 to 15 mL of this solution is infiltrated at three or four sites along the entire length of the internal thoracic artery. The dissection is then perAccepted for publication Feb 12, 1997. Address reprint requests to Mr Nair, Department of Cardiothoracic Surgery,, KillingbeckHospital, York Rd, Leeds, UK LS146UQ. © 1997 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
The injection of p a p a v e r i n e in the internal thoracic artery b e d facilitates easy a n d m i n i m a l l y traumatic harvesting b y hydrodissection. As the solution is injected into the space by the d e s c r i b e d technique, the internal thoracic artery stands out from the chest wall. In addition, dilation of the artery a n d its b r a n c h e s due to p a p a v e r i n e helps easy visualization a n d division. This has h e l p e d to expedite the harvesting of the internal thoracic artery without causing t r a u m a a n d c o n s e q u e n t spasm. A significant reduction in the m a x i m u m contractile response of the internal thoracic artery after p a p a v e r i n e t r e a t m e n t has b e e n d e m o n s t r a t e d b y Hillier a n d associates [5]. In our technique, as p a p a v e r i n e is injected even before the dissection is started, it dilates the artery a n d makes it less prone to severe spasm at the time of harvesting. Second, the mechanism of action of papaverine on the smooth muscle involves the inhibition of enzymatic activity a n d is o p t i m u m at 37°C [3]. Thus, infiltration around the internal thoracic artery with papaverine at the beginning allows it to act at the body temperature until the full length of the pedicle has been mobilized. Finally, keeping the pedicle intact avoids bathing of the internal thoracic artery in topical ice-cold saline solution. This technique allows longer duration of action by p a p a v e r i n e on the internal thoracic artery, at n e a r b o d y t e m p e r a t u r e , b e f o r e , d u r i n g , a n d after h a r v e s t i n g , t h e r e b y p r e v e n t i n g or m i n i m i z i n g the arterial spasm.
References 1. Mills NL, Bringaze WL. Preparation of the internal mammary artery graft. Which is the best method? J Thorac Cardiovasc Surg 1989;98:73-9. 2. Cooper GJ, Wilkinson GAL, Angelini GD. Overcoming perioperative spasm of the internal mammary artery: which is the best vasodilator? J Thorac Cardiovasc Surg 1992;104:4657.8. 3. Bilgen F, Yaplcl MF, Serbet~io~lu A, Tarhan A, ~oruh T, Ozler A. Effect of normothermic papaverine to relieve intraoperative spasm of the internal thoracic artery. Ann Thorac Surg 1996;62:769-71. 4. John LCH, Edmondson SJ, Rees GM. Modified technique of internal mammary artery harvest. Ann Thorac Surg 1991;52: 157-8. 5. Hillier C, Watt PAC, Sp~ TJ, Thurston H. Contraction and relaxation of human internal mammary artery after intraluminal administration of papaverine. Ann Thorac Surg 1992;53:1033-7. 0003-4975/97[$17.00 PII S0003-4975(97)00291-9