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Simplified Technique for Aortic Arch Replacement: First-Stage Right Subclavian-to-Left Carotid Artery Bypass
HOW TO DO IT
Simplified Technique for Aortic Arch Replacement First-Stage R i g h t Suhcluuian-to-Lejt Carotid Artery Bypass
S. R. Panday, M.D., G. B. Parulkar, M.D.,
A. P. Chaukar, M.D., and P. K. Sen, M.D. ABSTRACT A simplified operative and perfusion technique for aortic arch replacement is described. Prior to definitive operation a right subclavian-to-left carotid artery bypass is performed using a Dacron graft. At the time of aortic arch replacement the right axillary artery is cannulated; this perfuses the right subclavian, right carotid, and left carotid arteries through the shunt, thus perfusing the entire brain. The rest of the body is perfused through a cannula in the femoral artery. This technique obviates the hazards and inconvenience of direct cannulation of the carotid arteries through the aneurysmal sac. The creation of such a shunt also reduces the time required for arch replacement, as the left carotid artery does not need a separate anastomosis.
A
t present the operative technique for aortic arch replacement involves a complicated extracorporeal system by which the whole body is perfused through several individual ,perfusion pumps [ 11. Circulation in the lower part of the body is thus maintained through a femoral artery cannula, and the cerebral circulation is maintained through two other cannulas introduced directly into the innominate artery and left carotid artery. This technique has certain disadvantages. 1. Direct cannulation of the neck vessels close to the aneurysm increases
the chance of cerebral embolism during perfusion. These vessels are commonly involved in the disease, and there is thus greater risk of dissection starting at their mouths. 2. T h e perfusion cannulas introduced through the carotid arteries cause From the Department of Surgery, K. E. M. Hospital, Bombay 12, India. Accepted for publication Dec. 29, 1973. Address reprint requests to Dr. Panday, Department of Surgery, Seth G. S. Medical College and K. E. M. Hospital Parel, Bombay 12, India.
186
THE ANNALS OF THORACIC SURGERY
HOW TO DO IT:
Aortic Arch Replacemen1
interference during operative resection and tend to slip out, or there may be leaks around them. 3. Direct cannulation of the carotid vessels often necessitates temporary interruption of cerebral flow through these vessels while they are being reimplanted into the prefabricated graft used for replacement of the arch. In order to overcome some of these difficulties, a new technique of perfusion was devised. A few days before the definitive arch replacement operation, a shunt is created between the right subclavian artery and the left carotid artery using a Dacron graft (Fig. 1). This operation can be done under local anesthesia. At the time of aortic arch replacement, the right axillary artery is dissected and cannulated. Perfusion through the axillary cannula reaches not only the right subclavian and right carotid arteries but also the left carotid artery through the shunt, thus almost the entire brain is perfused (Fig. 2). With this simplified technique, we have been able to carry out resection and replacement of the aortic arch in 55 minutes of bypass time. Details are reported below. After the chest was opened through a median sternotomy, the ascending aorta and pulmonary artery were dissected and looped. T h e left pleura was then opened, and the descending thoracic aorta beyond the aneurysm was RIGHT SUBCLAVIANLEFT CAROTID SHUNT
ANEURYSM OF THE ARCH OF THE AORTA F I G . 1. Fusiform aneurysm of trnn~~ wrse arch of thc nortn nnd the right .~irhclrrainn-to-lel, cnrotid artery shunt done as the first stage of the operation.
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18,
NO. 2, AUGUST,
1974
187
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AXILLARY ARTERY
FEMORAL ARTERY
FIG. 2. T h e aneurysm excision. Note that the right axillary cannula perfuses not only the right subclavian and right carotid arteries but also the left carotid artery through the shunt, thus perfusing almost the entire brain. T h e lower part of the body receives blood through the femoral artery cannula.
SUBCLAVIAN
FIG. 3. Replacement of the entire arch of the aorta by a prefabricated Dacron graft is illustrated. Note that the left carotid artery has not been anastornosed to the graft, as it is being supplied through the right subclovion-to-left cnrotid artery shunt.
188
T H E ANNALS OF THORACIC SURGERY
HOW TO DO IT:
Aortic Arch Replacement
dissected and kept ready for clamping. Following this, the dissections of the innominate, left carotid, and left subclavian arteries were carried out. Normothermic perfusion was established using total dextrose prime. T h e venous return was through a single cannula in the right atrium. Oxygenated blood was returned to the patient through two pumps. T h e cerebral blood flow was maintained at between 800 and 1,000 ml. through the right axillary artery, and the rest of the flow was directed through the femoral artery cannula. After total bypass was established, the descending thoracic aorta was clamped. T h e left subclavian, left carotid, and innominate arteries were clamped later. T h e aneurysmal sac and arch of the aorta were now isolated, and the whole body was perfused except for the heart, which was under anoxic arrest. T h e aneurysm was carefully excised. T h e distal end of the prefabricated Dacron graft was sutured to the descending thoracic aorta. Following this, the proximal end of the graft was sutured to the ascending aorta. After evacuating all the air within the graft, the clamp on the descending thoracic aorta was removed, thus establishing coronary blood flow to the heart. T h e period of anoxic arrest was only 28 minutes, and normal heart action resumed spontaneously. T h e anastomoses to the innominate and left subclavian arteries were then completed, taking care to eliminate any trapped air (Fig. 3). Hemostasis was achieved, and the chest was closed in layers with proper drainage tubes. Immediately following operation, all pulses were palpable and the patient was fully conscious with a satisfactory blood pressure. T h e next day, however, even though the patient was maintaining a satisfactory blood pressure, cardiac arrhythmia suddenly developed. He later went into ventricular fibrillation from which he could not be resuscitated. Postmortem examination of gross and histopathological sections of the brain did not reveal any abnormality. T h e advantages of creating a right subclavian-to-left carotid artery shunt prior to definitive operation on the aortic arch are as follows: 1. When the cannula perfusing the brain is placed in the right axillary artery, it is some distance from the operative field and does not interfere with the operation. 2. T h e perfusion cannula in the axillary artery maintains uniform distribution of blood through the cerebral circulation. 3. Creation of the right subclavian-to-left carotid artery anastomosis reduces the time required for arch replacement since the left carotid artery need not be anastomosed separately to the p a f t used for replacement o f the arch.
PANDAY ET AL. T h e graft is anastomosed to the innominate artery alone and, if necessary, to the left subclavian artery as well. We believe creation of a right subclavian-to-left carotid artery anastomosis prior to definitive operation simplifies both perfusion for a n d the technique of aortic arch replacement.
Reference 1. Bloodwell, R. D., Hallman, G. L., and Cooley, D. A. Total replacement of the aortic arch and the “subclavian steal” phenomenon. Ann. Thorac. Surg. 5:236, 1968.
I M P O R T A N T A N N O U N C E M E N T FROM T H E AMERICAN BOARD OF T H O R A C I C XJRGERY Candidates for certification who begin their training in thoracic and cardiovascular surgery after June 30, 1976, will be accepted for examination only if they have completed two years of training in a program approved by the Residency Review Committee for Thoracic Surgery. Candidates trained in thoracic and cardiovascular surgery in programs not approved by the Residency Review Committee will no longer have their qualifications reviewed by the Credentials Committee on an individual basis. Candidates for certification who fail the examination three times must provide evidence that they have satisfactorily completed an additional year of training in an approved program before they will be considered for examination a fourth time. Candidates who apply for examination more than five years after the satisfactory completion of their residency must have an additional year of training in an approved program before they will be eligible to apply for examination. This ruling applies to candidates finishing their training in thoracic and cardiovascular surgery after January 1, 1975.
190
THE ANNALS OF THORACIC SURGERY
Simplified Technique for Aortic Arch Replacement First-Stage R i g h t Suhcluuian-to-Lejt Carotid Artery Bypass
S. R. Panday, M.D., G. B. Parulkar, M.D.,
A. P. Chaukar, M.D., and P. K. Sen, M.D. ABSTRACT A simplified operative and perfusion technique for aortic arch replacement is described. Prior to definitive operation a right subclavian-to-left carotid artery bypass is performed using a Dacron graft. At the time of aortic arch replacement the right axillary artery is cannulated; this perfuses the right subclavian, right carotid, and left carotid arteries through the shunt, thus perfusing the entire brain. The rest of the body is perfused through a cannula in the femoral artery. This technique obviates the hazards and inconvenience of direct cannulation of the carotid arteries through the aneurysmal sac. The creation of such a shunt also reduces the time required for arch replacement, as the left carotid artery does not need a separate anastomosis.
A
t present the operative technique for aortic arch replacement involves a complicated extracorporeal system by which the whole body is perfused through several individual ,perfusion pumps [ 11. Circulation in the lower part of the body is thus maintained through a femoral artery cannula, and the cerebral circulation is maintained through two other cannulas introduced directly into the innominate artery and left carotid artery. This technique has certain disadvantages. 1. Direct cannulation of the neck vessels close to the aneurysm increases
the chance of cerebral embolism during perfusion. These vessels are commonly involved in the disease, and there is thus greater risk of dissection starting at their mouths. 2. T h e perfusion cannulas introduced through the carotid arteries cause From the Department of Surgery, K. E. M. Hospital, Bombay 12, India. Accepted for publication Dec. 29, 1973. Address reprint requests to Dr. Panday, Department of Surgery, Seth G. S. Medical College and K. E. M. Hospital Parel, Bombay 12, India.
186
THE ANNALS OF THORACIC SURGERY
HOW TO DO IT:
Aortic Arch Replacemen1
interference during operative resection and tend to slip out, or there may be leaks around them. 3. Direct cannulation of the carotid vessels often necessitates temporary interruption of cerebral flow through these vessels while they are being reimplanted into the prefabricated graft used for replacement of the arch. In order to overcome some of these difficulties, a new technique of perfusion was devised. A few days before the definitive arch replacement operation, a shunt is created between the right subclavian artery and the left carotid artery using a Dacron graft (Fig. 1). This operation can be done under local anesthesia. At the time of aortic arch replacement, the right axillary artery is dissected and cannulated. Perfusion through the axillary cannula reaches not only the right subclavian and right carotid arteries but also the left carotid artery through the shunt, thus almost the entire brain is perfused (Fig. 2). With this simplified technique, we have been able to carry out resection and replacement of the aortic arch in 55 minutes of bypass time. Details are reported below. After the chest was opened through a median sternotomy, the ascending aorta and pulmonary artery were dissected and looped. T h e left pleura was then opened, and the descending thoracic aorta beyond the aneurysm was RIGHT SUBCLAVIANLEFT CAROTID SHUNT
ANEURYSM OF THE ARCH OF THE AORTA F I G . 1. Fusiform aneurysm of trnn~~ wrse arch of thc nortn nnd the right .~irhclrrainn-to-lel, cnrotid artery shunt done as the first stage of the operation.
VOL.
18,
NO. 2, AUGUST,
1974
187
ROTlD ED
R LE
1RYSM E ARCH
AXILLARY ARTERY
FEMORAL ARTERY
FIG. 2. T h e aneurysm excision. Note that the right axillary cannula perfuses not only the right subclavian and right carotid arteries but also the left carotid artery through the shunt, thus perfusing almost the entire brain. T h e lower part of the body receives blood through the femoral artery cannula.
SUBCLAVIAN
FIG. 3. Replacement of the entire arch of the aorta by a prefabricated Dacron graft is illustrated. Note that the left carotid artery has not been anastornosed to the graft, as it is being supplied through the right subclovion-to-left cnrotid artery shunt.
188
T H E ANNALS OF THORACIC SURGERY
HOW TO DO IT:
Aortic Arch Replacement
dissected and kept ready for clamping. Following this, the dissections of the innominate, left carotid, and left subclavian arteries were carried out. Normothermic perfusion was established using total dextrose prime. T h e venous return was through a single cannula in the right atrium. Oxygenated blood was returned to the patient through two pumps. T h e cerebral blood flow was maintained at between 800 and 1,000 ml. through the right axillary artery, and the rest of the flow was directed through the femoral artery cannula. After total bypass was established, the descending thoracic aorta was clamped. T h e left subclavian, left carotid, and innominate arteries were clamped later. T h e aneurysmal sac and arch of the aorta were now isolated, and the whole body was perfused except for the heart, which was under anoxic arrest. T h e aneurysm was carefully excised. T h e distal end of the prefabricated Dacron graft was sutured to the descending thoracic aorta. Following this, the proximal end of the graft was sutured to the ascending aorta. After evacuating all the air within the graft, the clamp on the descending thoracic aorta was removed, thus establishing coronary blood flow to the heart. T h e period of anoxic arrest was only 28 minutes, and normal heart action resumed spontaneously. T h e anastomoses to the innominate and left subclavian arteries were then completed, taking care to eliminate any trapped air (Fig. 3). Hemostasis was achieved, and the chest was closed in layers with proper drainage tubes. Immediately following operation, all pulses were palpable and the patient was fully conscious with a satisfactory blood pressure. T h e next day, however, even though the patient was maintaining a satisfactory blood pressure, cardiac arrhythmia suddenly developed. He later went into ventricular fibrillation from which he could not be resuscitated. Postmortem examination of gross and histopathological sections of the brain did not reveal any abnormality. T h e advantages of creating a right subclavian-to-left carotid artery shunt prior to definitive operation on the aortic arch are as follows: 1. When the cannula perfusing the brain is placed in the right axillary artery, it is some distance from the operative field and does not interfere with the operation. 2. T h e perfusion cannula in the axillary artery maintains uniform distribution of blood through the cerebral circulation. 3. Creation of the right subclavian-to-left carotid artery anastomosis reduces the time required for arch replacement since the left carotid artery need not be anastomosed separately to the p a f t used for replacement o f the arch.
PANDAY ET AL. T h e graft is anastomosed to the innominate artery alone and, if necessary, to the left subclavian artery as well. We believe creation of a right subclavian-to-left carotid artery anastomosis prior to definitive operation simplifies both perfusion for a n d the technique of aortic arch replacement.
Reference 1. Bloodwell, R. D., Hallman, G. L., and Cooley, D. A. Total replacement of the aortic arch and the “subclavian steal” phenomenon. Ann. Thorac. Surg. 5:236, 1968.
I M P O R T A N T A N N O U N C E M E N T FROM T H E AMERICAN BOARD OF T H O R A C I C XJRGERY Candidates for certification who begin their training in thoracic and cardiovascular surgery after June 30, 1976, will be accepted for examination only if they have completed two years of training in a program approved by the Residency Review Committee for Thoracic Surgery. Candidates trained in thoracic and cardiovascular surgery in programs not approved by the Residency Review Committee will no longer have their qualifications reviewed by the Credentials Committee on an individual basis. Candidates for certification who fail the examination three times must provide evidence that they have satisfactorily completed an additional year of training in an approved program before they will be considered for examination a fourth time. Candidates who apply for examination more than five years after the satisfactory completion of their residency must have an additional year of training in an approved program before they will be eligible to apply for examination. This ruling applies to candidates finishing their training in thoracic and cardiovascular surgery after January 1, 1975.
190
THE ANNALS OF THORACIC SURGERY