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Novel Technique for Aortic Arch Surgery Under Mild Hypothermia
Novel Technique for Aortic Arch Surgery Under Mild Hypothermia Aristotelis Panos, MD, FEBTCS, Patrick-Olivier Myers, MD, and Afkskendiyos Kalangos, MD, PhD Clinic for Cardiovascular Surgery, University Hospital of Geneva, Geneva, Switzerland
We present our initial experience in 5 patients for open aortic arch repair with continuous antegrade perfusion of the brain and of the lower body by means of direct cannulation of the right axillary artery and of the descending aorta with a venous cannula (DLP 91037 cannula [Medtronic Inc, Minneapolis, MN]) for systemic perfusion under mild hypothermia (30°C). This mode of perfusion allows safe open repair of the aortic arch, short
aortic cross clamping, and CPB times associated to all the known advantages of the mild hypothermia; this technique could have the potential to be generally applicable in surgeries for aortic arch repairs after further evaluation.
O
cannula after systemic heparinization. The operations were conducted through midline sternotomies and CPB was installed through the right axillary artery and right femoral vein for the redo patients. The patient was cooled to a rectal temperature of 30°C. During cooling, the aortic arch and neck vessels were prepared for control. The ascending aortic graft was cross clamped and cold blood cardioplegia was delivered in all but 1 patient, in which warm cardioplegia was delivered; all cardioplegia was delivered in an antegrade manner to achieve cardiac arrest. At 30°C the systemic flow rate of the CPB was halted. The three-neck vessels were clamped individually with neonatal clamps and the aortic cross clamp was released. During this period of systemic circulatory arrest, the brain was continuously perfused through the right axillary artery to a flow rate of 12 mL/kg/min and a mean arterial pressure of 60 mm Hg [1]. Peroperative blood flow through the middle cerebral arteries was monitored continuously with bilateral transcranial Doppler. If an asymmetry of the blood flow was noticed, cannulation of the left common carotid artery would be performed. None of our patients showed such an asymmetry. The aortic arch was incised and the pathologic tissues were transected. At this moment, we introduced the arterial line connected to the DLP cannula through the new Dacron graft (DuPont, Wilmington, DE) and then within the descending aorta (Fig 1). The balloon was then inflated to achieve a blood proof occlusion of the aorta, and at the same time, the systemic blood flow increased progressively to the normal systemic rate according to the body area index of each patient. The lower body circulatory arrest was of 7.2 ⫾ 1.1 min. Adequate perfusion of the cerebral and lower body by both cannulas was monitored by the systemic pressures measured by a femoral artery catheter and the transcranial Doppler. A gelatin-coated Dacron tube graft was anastomosed distally to the descending aorta in an open way while
Technique All of the patients gave informed consent for their operation. The cardiopulmonary bypass (CPB) lines and cannulas were prepared before starting each operation. A “Y” connector was mounted on the arterial line to split the flow in two lines. One was connected to the axillary artery cannula (22-French to 24-French [Terumo arterial cannula; Terumo, Ann Arbor, MI]) and the other to the DLP cannula. The right axillary artery was exposed through a subclavicular incision and was cannulated directly, with the straight 22-French to 24-French arterial Accepted for publication June 15, 2007. Address correspondence to Dr Panos, Clinic for Cardiac Surgery, University Hospital of Geneva, 24, Rue Micheli-du-Crest, Geneva, 14 1211, Switzerland; e-mail: [email protected].
© 2008 by The Society of Thoracic Surgeons Published by Elsevier Inc
0003-4975/08/$34.00 doi:10.1016/j.athoracsur.2007.06.046
FEATURE ARTICLES
ur technique was evaluated between March 2005 and September 2006 in 5 consecutive patients (ie, 4 men and 1 woman) with aortic arch aneurysms who underwent surgery for replacement of the aortic arch and were prospectively evaluated. The age at operation ranged from 29 to 75 years (mean, 55.6 ⫾ 17 years). Three patients were redo operations. The first operation was for a type A aortic dissection and the ascending aorta, which was already replaced in all 3 patients. All of these patients also had the false lumen thrombosed. These patients underwent a total aortic arch replacement, and in 1 patient, the replacement was extended to the thoracic descending aorta. For the arterial perfusion of the lower body we used a single-stage venous cannula (DLP 91037, 37-French cannula [Medtronic Inc, Minneapolis, MN]) with an inflatable cuff on its extremity. The silicon occlusive balloon can be inflated with saline to create an aortic tape. The maximum safe diameter of the balloon is 6.35 cm with a tested pressure of 60 mm Hg.
(Ann Thorac Surg 2008;85:347– 8) © 2008 by The Society of Thoracic Surgeons
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HOW TO DO IT PANOS ET AL AORTIC ARCH SURGERY UNDER MILD HYPOTHERMIA
FEATURE ARTICLES
Fig 1. Schematic representation of the operating field with the arterial line connected to the DLP 91037 cannula (Medtronic Inc, Minneapolis, MN) through the Dacron graft (DuPont, Wilmington, DE) and then within the descending aorta. The arrows indicate the perfusion flow through the right axillary artery and the DLP cannula.
rewarming was initiated. After the completion of the distal anastomosis, the neck vessels were anastomosed onto the same Dacron graft (DuPont) in an islet fashion. The blood flow was then decreased again, the balloon was de-inflated, the cannula was retrieved, and the air was removed from the graft. A clamp was applied just proximal to the last anastomosis and the systemic blood flow resumed only through the right axillary cannula. The proximal anastomosis was performed between the previous graft and the new graft (for the redo patients and to the ascending aorta for the primary operation patients). The clamp on the graft was then released. The operation was completed in the usual way. Mean duration of CPB and aortic cross clamp were 138 ⫾ 9.1 and 62 ⫾ 5.7 minutes, respectively. The postoperative course was uneventful and all the patients were discharged from the hospital.
Comment Open distal aortic repair is widely admitted for aortic arch repair. This technique requires a continuous antegrade cerebral perfusion and an interval of deep or moderate hypothermic circulatory arrest of the lower body. On the other hand, the safe duration of the hypothermic arrest is finite and hypothermia-related coagulopathy constitutes an additional disadvantage for this technique. In our technique, the brain and lower body are continuously perfused with only a very limited circu-
Ann Thorac Surg 2008;85:347– 8
latory arrest (6 to 8 minutes) of the lower body. The duration of the circulatory arrest in the lower body corresponds to the necessary time for the resection of the aortic tissues, positioning of the DLP cannula in the descending aorta and the inflation of the occlusion balloon. In this way, we aim to transform an arch repair operation to a standard CPB heart operation. The peroperative bilateral transcranial Doppler monitoring of the blood flow through the middle cerebral artery is of capital importance. If an asymmetry in the blood flow between both cerebral arteries is noticed, selective cannulation of the left common carotid must be performed. The 8 minutes limited duration of the circulatory arrest in the lower body is safe for the spinal cord and splanchnic organs at this temperature and even in normothermia [2, 3]. With the use of mild hypothermia we are avoiding the systemic deleterious effects of deep hypothermia, especially on platelet activation pathways and on the enzymatic activity of clotting factors. The occlusion balloon was very efficient in obtaining a blood proof field to perform an open type anastomosis and at the same time obtaining a full flow antegrade perfusion of the lower body. Overdistension of the aorta when inflating the cuff of the cannula is precluded by the presence of a security small and easily distensible balloon just after the inflation tip of the cannula. When this small balloon inflates, inflation of the cuff must stop. Times of CPB are also shorter with this method because the duration of rewarming is less and because rewarming begins already during the construction of the distal anastomosis. These CPB times are shorter, independently of the use of a straight or four-branched graft, and the cannulation of the newly implanted graft is not necessary to achieve an antegrade systemic perfusion after the completion of the distal aortic anastomosis. Other authors [4] proposed aortic arch surgery under mild hypothermia, but through an association of continuous antegrade cerebral perfusion from the right axillary artery and through the right femoral artery. Indeed, this technique does not permit an open type distal aortic anastomosis and also has the drawbacks of the retrograde descending aortic perfusion. We believe that this technique could be seriously considered in the armamentarium of the perfusion techniques for aortic arch surgery after further evaluation and subsequent improvement of the cannula according to its “new” tasks.
References 1. Jacobs M, de Mol B, Veldman D. Aortic arch and proximal supraaortic arterial repair under continuous antegrade cerebral perfusion and moderate hypothermia. Cardiovasc Surg 2001;9:396 – 402. 2. Kirklin J, Barrat-Boyes B. Hypothermia and total circulatory arrest. In: Cardiac Surgery, 2nd ed. New York, NY; ChurchillLivingstone, 1993:1712–3. 3. Laven B, Orvietto M, Chuang M. Renal tolerance to prolonged warm ischemia time in a laparoscopic versus open surgery porcine model. J Urol 2004;172:2471– 4. 4. Emrecan B, Yilik L, Tulukoglu E, et al. Whole-body perfusion under moderate-degree hypothermia during aortic arch repair. Heart Surg Forum 2006;9:E686.
We present our initial experience in 5 patients for open aortic arch repair with continuous antegrade perfusion of the brain and of the lower body by means of direct cannulation of the right axillary artery and of the descending aorta with a venous cannula (DLP 91037 cannula [Medtronic Inc, Minneapolis, MN]) for systemic perfusion under mild hypothermia (30°C). This mode of perfusion allows safe open repair of the aortic arch, short
aortic cross clamping, and CPB times associated to all the known advantages of the mild hypothermia; this technique could have the potential to be generally applicable in surgeries for aortic arch repairs after further evaluation.
O
cannula after systemic heparinization. The operations were conducted through midline sternotomies and CPB was installed through the right axillary artery and right femoral vein for the redo patients. The patient was cooled to a rectal temperature of 30°C. During cooling, the aortic arch and neck vessels were prepared for control. The ascending aortic graft was cross clamped and cold blood cardioplegia was delivered in all but 1 patient, in which warm cardioplegia was delivered; all cardioplegia was delivered in an antegrade manner to achieve cardiac arrest. At 30°C the systemic flow rate of the CPB was halted. The three-neck vessels were clamped individually with neonatal clamps and the aortic cross clamp was released. During this period of systemic circulatory arrest, the brain was continuously perfused through the right axillary artery to a flow rate of 12 mL/kg/min and a mean arterial pressure of 60 mm Hg [1]. Peroperative blood flow through the middle cerebral arteries was monitored continuously with bilateral transcranial Doppler. If an asymmetry of the blood flow was noticed, cannulation of the left common carotid artery would be performed. None of our patients showed such an asymmetry. The aortic arch was incised and the pathologic tissues were transected. At this moment, we introduced the arterial line connected to the DLP cannula through the new Dacron graft (DuPont, Wilmington, DE) and then within the descending aorta (Fig 1). The balloon was then inflated to achieve a blood proof occlusion of the aorta, and at the same time, the systemic blood flow increased progressively to the normal systemic rate according to the body area index of each patient. The lower body circulatory arrest was of 7.2 ⫾ 1.1 min. Adequate perfusion of the cerebral and lower body by both cannulas was monitored by the systemic pressures measured by a femoral artery catheter and the transcranial Doppler. A gelatin-coated Dacron tube graft was anastomosed distally to the descending aorta in an open way while
Technique All of the patients gave informed consent for their operation. The cardiopulmonary bypass (CPB) lines and cannulas were prepared before starting each operation. A “Y” connector was mounted on the arterial line to split the flow in two lines. One was connected to the axillary artery cannula (22-French to 24-French [Terumo arterial cannula; Terumo, Ann Arbor, MI]) and the other to the DLP cannula. The right axillary artery was exposed through a subclavicular incision and was cannulated directly, with the straight 22-French to 24-French arterial Accepted for publication June 15, 2007. Address correspondence to Dr Panos, Clinic for Cardiac Surgery, University Hospital of Geneva, 24, Rue Micheli-du-Crest, Geneva, 14 1211, Switzerland; e-mail: [email protected].
© 2008 by The Society of Thoracic Surgeons Published by Elsevier Inc
0003-4975/08/$34.00 doi:10.1016/j.athoracsur.2007.06.046
FEATURE ARTICLES
ur technique was evaluated between March 2005 and September 2006 in 5 consecutive patients (ie, 4 men and 1 woman) with aortic arch aneurysms who underwent surgery for replacement of the aortic arch and were prospectively evaluated. The age at operation ranged from 29 to 75 years (mean, 55.6 ⫾ 17 years). Three patients were redo operations. The first operation was for a type A aortic dissection and the ascending aorta, which was already replaced in all 3 patients. All of these patients also had the false lumen thrombosed. These patients underwent a total aortic arch replacement, and in 1 patient, the replacement was extended to the thoracic descending aorta. For the arterial perfusion of the lower body we used a single-stage venous cannula (DLP 91037, 37-French cannula [Medtronic Inc, Minneapolis, MN]) with an inflatable cuff on its extremity. The silicon occlusive balloon can be inflated with saline to create an aortic tape. The maximum safe diameter of the balloon is 6.35 cm with a tested pressure of 60 mm Hg.
(Ann Thorac Surg 2008;85:347– 8) © 2008 by The Society of Thoracic Surgeons
348
HOW TO DO IT PANOS ET AL AORTIC ARCH SURGERY UNDER MILD HYPOTHERMIA
FEATURE ARTICLES
Fig 1. Schematic representation of the operating field with the arterial line connected to the DLP 91037 cannula (Medtronic Inc, Minneapolis, MN) through the Dacron graft (DuPont, Wilmington, DE) and then within the descending aorta. The arrows indicate the perfusion flow through the right axillary artery and the DLP cannula.
rewarming was initiated. After the completion of the distal anastomosis, the neck vessels were anastomosed onto the same Dacron graft (DuPont) in an islet fashion. The blood flow was then decreased again, the balloon was de-inflated, the cannula was retrieved, and the air was removed from the graft. A clamp was applied just proximal to the last anastomosis and the systemic blood flow resumed only through the right axillary cannula. The proximal anastomosis was performed between the previous graft and the new graft (for the redo patients and to the ascending aorta for the primary operation patients). The clamp on the graft was then released. The operation was completed in the usual way. Mean duration of CPB and aortic cross clamp were 138 ⫾ 9.1 and 62 ⫾ 5.7 minutes, respectively. The postoperative course was uneventful and all the patients were discharged from the hospital.
Comment Open distal aortic repair is widely admitted for aortic arch repair. This technique requires a continuous antegrade cerebral perfusion and an interval of deep or moderate hypothermic circulatory arrest of the lower body. On the other hand, the safe duration of the hypothermic arrest is finite and hypothermia-related coagulopathy constitutes an additional disadvantage for this technique. In our technique, the brain and lower body are continuously perfused with only a very limited circu-
Ann Thorac Surg 2008;85:347– 8
latory arrest (6 to 8 minutes) of the lower body. The duration of the circulatory arrest in the lower body corresponds to the necessary time for the resection of the aortic tissues, positioning of the DLP cannula in the descending aorta and the inflation of the occlusion balloon. In this way, we aim to transform an arch repair operation to a standard CPB heart operation. The peroperative bilateral transcranial Doppler monitoring of the blood flow through the middle cerebral artery is of capital importance. If an asymmetry in the blood flow between both cerebral arteries is noticed, selective cannulation of the left common carotid must be performed. The 8 minutes limited duration of the circulatory arrest in the lower body is safe for the spinal cord and splanchnic organs at this temperature and even in normothermia [2, 3]. With the use of mild hypothermia we are avoiding the systemic deleterious effects of deep hypothermia, especially on platelet activation pathways and on the enzymatic activity of clotting factors. The occlusion balloon was very efficient in obtaining a blood proof field to perform an open type anastomosis and at the same time obtaining a full flow antegrade perfusion of the lower body. Overdistension of the aorta when inflating the cuff of the cannula is precluded by the presence of a security small and easily distensible balloon just after the inflation tip of the cannula. When this small balloon inflates, inflation of the cuff must stop. Times of CPB are also shorter with this method because the duration of rewarming is less and because rewarming begins already during the construction of the distal anastomosis. These CPB times are shorter, independently of the use of a straight or four-branched graft, and the cannulation of the newly implanted graft is not necessary to achieve an antegrade systemic perfusion after the completion of the distal aortic anastomosis. Other authors [4] proposed aortic arch surgery under mild hypothermia, but through an association of continuous antegrade cerebral perfusion from the right axillary artery and through the right femoral artery. Indeed, this technique does not permit an open type distal aortic anastomosis and also has the drawbacks of the retrograde descending aortic perfusion. We believe that this technique could be seriously considered in the armamentarium of the perfusion techniques for aortic arch surgery after further evaluation and subsequent improvement of the cannula according to its “new” tasks.
References 1. Jacobs M, de Mol B, Veldman D. Aortic arch and proximal supraaortic arterial repair under continuous antegrade cerebral perfusion and moderate hypothermia. Cardiovasc Surg 2001;9:396 – 402. 2. Kirklin J, Barrat-Boyes B. Hypothermia and total circulatory arrest. In: Cardiac Surgery, 2nd ed. New York, NY; ChurchillLivingstone, 1993:1712–3. 3. Laven B, Orvietto M, Chuang M. Renal tolerance to prolonged warm ischemia time in a laparoscopic versus open surgery porcine model. J Urol 2004;172:2471– 4. 4. Emrecan B, Yilik L, Tulukoglu E, et al. Whole-body perfusion under moderate-degree hypothermia during aortic arch repair. Heart Surg Forum 2006;9:E686.