HOW TO DO IT
Internal Mammary Artery Cannulation Hillel Laks, M.D., Kenneth Rongey, M.D., John Schweiss, M.D., and Vallee L. Willman, M.D. ABSTRACT A technique of internal mammary artery cannulation is described. This approach offers a safe method for arterial monitoring in infants undergoing thoracotomy for palliative cardiac procedures.
Neonates undergoing palliative cardiac procedures are frequently severely cyanotic and acidotic. Arterial cannulation allows continuous monitoring of arterial pressure and enables arterial gases and pH to be measured during and after the procedure. Radial 12, 61, brachial [ll, umbilical [3,71, and temporal [5] artery cannulations have been described. Our experience has shown that cannulation of the internal mammary artery (IMA) offers a convenient and safe alternative method of arterial monitoring in infants undergoing thoracotomy.
Technique The standard thoracotomy incision used is similar for the Blalock-Taussig shunt, the Glenn shunt, the Blalock-Hanlon procedure, and pulmonary artery banding. The incision is made in the breast crease, starting in the midclavicular line and extending to a point one finger's breadth inferior and posterior to the tip of the scapula. Particularly in female patients, an incision too close to the nipple, or extension of the incision more medially, gives a poor cosmetic result. The IMA and vein can be easily exposed through this incision (Figure). A polyethylene catheter* (PE50,0.058 cm inner diameter, 0.0196 cm outer diameter) is used to cannulate the artery. If a Blalock-Taussig shunt is to be performed, the cannula is directed inferiorly as the proximal end of the internal mammary artery is divided in taking down the subclavian artery. This gives an excellent pulsatile tracing, as
shown in the Figure, and allows for arterial sampling. If the artery is small, a 2-0 stainless steel wire may be used as an introducer. The cannula is brought out obliquely through an adjacent intercostal space using a No. 18 thinwalled needle, avoiding kinking of the cannula. A pull-out stitch is left around the artery in the proximal interspace to occlude the artery after the catheter is removed. The ligature is tied around a rolled gauze pad so as to avoid skin necrosis. If required, the internal mammary vein may also be cannulated and the catheter directed centrally.
Results Since 1966, IMA cannulas have been used in more than 1,000 patients. This includes 90 infants who underwent pulmonary artery banding, 12 neonates under 1 month of age who underwent the Blalock-Taussig shunt, and 26 infants under 1 year of age who underwent coarctation repair. Until July, 1974, this technique was used for arterial monitoring in all open-heart procedures in children. Since then, percutaneous radial artery cannulation has been used for open procedures except when the radial artery was not available. In palliative procedures on infants, or when the radial artery is not available, IMA cannulation continues to be used. There have been 3 complications during this period. Early in our experience, the cannula was inadvertently withdrawn immediately postoperatively in a patient without a pull-out stitch. In a second patient an intercostal branch continued to bleed after removal of the cannula, and reoperation was required to control the bleeding. In the third patient the pull-out ligature was tied without a gauze roll, causing a small area of skin necrosis.
From the Saint Louis University Hospitals, St Louis, MO. Accepted for publication Mar 2, 1977. Address reprint requests to Dr. Laks, Department of Surgery, Yale University Medical School, 333 Cedar St, New Haven, CT 06510. *Intramedic, Clay Adams, Parsippany, NJ.
488
Comment IMA cannulation reliably reflects arterial pressure and may be used for the monitoring of blood gases during palliative procedures. In pa-
489
How to Do It: Laks et al: IMA Cannulation
The thoracotomy incision is depicted, with cannulation of the internal mammary artery and placement of the pullout ligature. The pulsatile arterial tracing is shown. The left inset shows the polyethylene catheter being inserted with a 2-0 stainless steel wire as an intrcducer. The right inset shows the closed incision with the pull-out ligature tied around a gauze roll.
tients undergoing a Blalock-Taussig shunt and ligation of the IMA, retrograde cannulation may be used. Collaterals consisting of intercostal arteries and the epigastric artery provide sufficient blood flow [4] to give a good pulsatile trace and to allow withdrawal of blood samples. There has been good correlation between the arterial pressure measured this way and that obtained by Doppler ultrasound. IMA cannulation is remarkably free of complications. The 3 complications that occurred in this series of more than 1,000 procedures were preventable by proper technique. The complica-
tions of radial artery cannulation have been well described. Radial and brachial artery cannulation can result in ischemia or even loss of the hand [2]. Good results have been reported with radial artery cannulation in the newborn [61. Technically, however, IMA cannulation is easier to perform than a radial artery cutdown in neonates and spares the remaining artery after a Blalock-Taussig shunt. With retrograde IMA cannulation there is also less danger of embolization by inadvertent flushing of air or thrombi intraarterially. Umbilical artery cannulation has potential lethal complications [3, 71, and temporal artery cannulation [51 may result in facial skin slough. Monitoring of arterial pressure and blood gases may be critical in the severely cyanotic infant. Despite what appears to be adequate ventilation, we have sometimes found a high PCO, and severe acidosis while the lung is re-
490 The Annals of Thoracic Surgery Vol 24 No 5 November 1977
#
tracted. During pulmonary artery banding, the gradient across the band as well as an elevation of systemic arterial pressure of about 15 mm Hg have been used as indicators of adequate banding [8]. The arterial pressure trace facilitates this measurement. The ratio of systemic systolic pressure to pulmonary artery pressure may also be measured in this way to calculate the gradient achieved by the band as it is tightened. We have found IMA cannulation to be a safe and convenient method of intraarterial monitoring in the neonate undergoing thoracotomy.
References 1. Barnes RW, Foster EJ, Janssen GA, et al: Safety of brachial arterial catheters as monitors in the intensive care unit: prospective evaluation with the Doppler ultrasonic velocity detector. Anesthesiology 44:260, 1976
2. Bedford RF, Wollman H: Complications of percutaneous radial artery cannulation. Anesthesiology 38:228, 1973 3. Cochran WD, Davis HT, Smith CA: Advantages and complications of umbilical artery catheterization in the newborn. Pediatrics 42:769, 1968 4. Florian AF, Lamberti JJ, Cohn LH, et al: Revascularization of the right coronary artery by retrograde perfusion of the mammary artery. J Thorac Cardiovasc Surg 70:19, 1975 5. Gauderer M, Holgersen LO: Peripheral arterial line insertion in neonates and infants: a simplified method of temporal artery cannulation. J Pediatr Surg 9:875, 1974 6. Todes ID, Rogers MC, Shannon DC, et al: Percutaneous catheterization of the radial artery in the critically ill neonate. J Pediatr 87:273, 1975 7. Tooley WH: What is the risk of an umbilical artery catheter? Pediatrics 50: 1, 1972 8. Utley JR: Hemodynamic observations during and after pulmonary artery banding. Ann Thorac Surg 15:493, 1973
Internal Mammary Artery Cannulation Hillel Laks, M.D., Kenneth Rongey, M.D., John Schweiss, M.D., and Vallee L. Willman, M.D. ABSTRACT A technique of internal mammary artery cannulation is described. This approach offers a safe method for arterial monitoring in infants undergoing thoracotomy for palliative cardiac procedures.
Neonates undergoing palliative cardiac procedures are frequently severely cyanotic and acidotic. Arterial cannulation allows continuous monitoring of arterial pressure and enables arterial gases and pH to be measured during and after the procedure. Radial 12, 61, brachial [ll, umbilical [3,71, and temporal [5] artery cannulations have been described. Our experience has shown that cannulation of the internal mammary artery (IMA) offers a convenient and safe alternative method of arterial monitoring in infants undergoing thoracotomy.
Technique The standard thoracotomy incision used is similar for the Blalock-Taussig shunt, the Glenn shunt, the Blalock-Hanlon procedure, and pulmonary artery banding. The incision is made in the breast crease, starting in the midclavicular line and extending to a point one finger's breadth inferior and posterior to the tip of the scapula. Particularly in female patients, an incision too close to the nipple, or extension of the incision more medially, gives a poor cosmetic result. The IMA and vein can be easily exposed through this incision (Figure). A polyethylene catheter* (PE50,0.058 cm inner diameter, 0.0196 cm outer diameter) is used to cannulate the artery. If a Blalock-Taussig shunt is to be performed, the cannula is directed inferiorly as the proximal end of the internal mammary artery is divided in taking down the subclavian artery. This gives an excellent pulsatile tracing, as
shown in the Figure, and allows for arterial sampling. If the artery is small, a 2-0 stainless steel wire may be used as an introducer. The cannula is brought out obliquely through an adjacent intercostal space using a No. 18 thinwalled needle, avoiding kinking of the cannula. A pull-out stitch is left around the artery in the proximal interspace to occlude the artery after the catheter is removed. The ligature is tied around a rolled gauze pad so as to avoid skin necrosis. If required, the internal mammary vein may also be cannulated and the catheter directed centrally.
Results Since 1966, IMA cannulas have been used in more than 1,000 patients. This includes 90 infants who underwent pulmonary artery banding, 12 neonates under 1 month of age who underwent the Blalock-Taussig shunt, and 26 infants under 1 year of age who underwent coarctation repair. Until July, 1974, this technique was used for arterial monitoring in all open-heart procedures in children. Since then, percutaneous radial artery cannulation has been used for open procedures except when the radial artery was not available. In palliative procedures on infants, or when the radial artery is not available, IMA cannulation continues to be used. There have been 3 complications during this period. Early in our experience, the cannula was inadvertently withdrawn immediately postoperatively in a patient without a pull-out stitch. In a second patient an intercostal branch continued to bleed after removal of the cannula, and reoperation was required to control the bleeding. In the third patient the pull-out ligature was tied without a gauze roll, causing a small area of skin necrosis.
From the Saint Louis University Hospitals, St Louis, MO. Accepted for publication Mar 2, 1977. Address reprint requests to Dr. Laks, Department of Surgery, Yale University Medical School, 333 Cedar St, New Haven, CT 06510. *Intramedic, Clay Adams, Parsippany, NJ.
488
Comment IMA cannulation reliably reflects arterial pressure and may be used for the monitoring of blood gases during palliative procedures. In pa-
489
How to Do It: Laks et al: IMA Cannulation
The thoracotomy incision is depicted, with cannulation of the internal mammary artery and placement of the pullout ligature. The pulsatile arterial tracing is shown. The left inset shows the polyethylene catheter being inserted with a 2-0 stainless steel wire as an intrcducer. The right inset shows the closed incision with the pull-out ligature tied around a gauze roll.
tients undergoing a Blalock-Taussig shunt and ligation of the IMA, retrograde cannulation may be used. Collaterals consisting of intercostal arteries and the epigastric artery provide sufficient blood flow [4] to give a good pulsatile trace and to allow withdrawal of blood samples. There has been good correlation between the arterial pressure measured this way and that obtained by Doppler ultrasound. IMA cannulation is remarkably free of complications. The 3 complications that occurred in this series of more than 1,000 procedures were preventable by proper technique. The complica-
tions of radial artery cannulation have been well described. Radial and brachial artery cannulation can result in ischemia or even loss of the hand [2]. Good results have been reported with radial artery cannulation in the newborn [61. Technically, however, IMA cannulation is easier to perform than a radial artery cutdown in neonates and spares the remaining artery after a Blalock-Taussig shunt. With retrograde IMA cannulation there is also less danger of embolization by inadvertent flushing of air or thrombi intraarterially. Umbilical artery cannulation has potential lethal complications [3, 71, and temporal artery cannulation [51 may result in facial skin slough. Monitoring of arterial pressure and blood gases may be critical in the severely cyanotic infant. Despite what appears to be adequate ventilation, we have sometimes found a high PCO, and severe acidosis while the lung is re-
490 The Annals of Thoracic Surgery Vol 24 No 5 November 1977
#
tracted. During pulmonary artery banding, the gradient across the band as well as an elevation of systemic arterial pressure of about 15 mm Hg have been used as indicators of adequate banding [8]. The arterial pressure trace facilitates this measurement. The ratio of systemic systolic pressure to pulmonary artery pressure may also be measured in this way to calculate the gradient achieved by the band as it is tightened. We have found IMA cannulation to be a safe and convenient method of intraarterial monitoring in the neonate undergoing thoracotomy.
References 1. Barnes RW, Foster EJ, Janssen GA, et al: Safety of brachial arterial catheters as monitors in the intensive care unit: prospective evaluation with the Doppler ultrasonic velocity detector. Anesthesiology 44:260, 1976
2. Bedford RF, Wollman H: Complications of percutaneous radial artery cannulation. Anesthesiology 38:228, 1973 3. Cochran WD, Davis HT, Smith CA: Advantages and complications of umbilical artery catheterization in the newborn. Pediatrics 42:769, 1968 4. Florian AF, Lamberti JJ, Cohn LH, et al: Revascularization of the right coronary artery by retrograde perfusion of the mammary artery. J Thorac Cardiovasc Surg 70:19, 1975 5. Gauderer M, Holgersen LO: Peripheral arterial line insertion in neonates and infants: a simplified method of temporal artery cannulation. J Pediatr Surg 9:875, 1974 6. Todes ID, Rogers MC, Shannon DC, et al: Percutaneous catheterization of the radial artery in the critically ill neonate. J Pediatr 87:273, 1975 7. Tooley WH: What is the risk of an umbilical artery catheter? Pediatrics 50: 1, 1972 8. Utley JR: Hemodynamic observations during and after pulmonary artery banding. Ann Thorac Surg 15:493, 1973
