| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
J Thorac Cardiovasc Surg 1994;107:1237-1243
© 1994 Mosby, Inc.
CARDIOPULMONARY BYPASS, |
Nagoya, Japan
From the Department of Thoracic Surgery, Nagoya University School of Medicine, Nagoya, Japan.
Received for publication May 21, 1993. Accepted for publication Sept. 27, 1993. Address for reprints: Kenzo Yasuura, MD, Department of Thoracic Surgery, Nagoya University School of Medicine, Tsurumai-chou 65, Shouwa-ku, Nagoya, Japan.
Abstract
Aneurysms involving either the aortic arch or the proximal descending thoracic aorta in five patients were resected with the aid of profound hypothermic total body retrograde perfusion. Traditional surgical management of the aortic arch and the descending thoracic aorta necessitates clamping of the aorta. However, this technique may be associated with rupture or atheroembolism. Rupture occurring at the clamping site may be difficult to repair. Atheroembolism to the brain compromises the neurologic system, and multiple organ embolism is associated with disseminated intravascular coagulopathy. Atheroembolism in cardiovascular surgery has become increasingly prevalent. It is necessary to prevent clamp injuries and to preserve the function of the vital organs, such as the brain, heart, and liver, during aortic reconstruction. We applied a total body retrograde perfusion technique to operations for aortic aneurysms. Total body retrograde perfusion consists of cerebral protection by continuous perfusion through the superior vena cava, intermittent retrograde coronary perfusion through the coronary sinus, and continuous abdominal visceral perfusion through the inferior vena cava. It can yield a relatively bloodless operating field without the need for aortic clamping. We believe this new adjunct offers excellent results in the surgical treatment of aneurysms of the aortic arch or adjacent structures. (J THORACCARDIOVASCSURG1994;107:1237-43)
Surgical correction of aneurysms involving the transverse aortic arch or adjacent areas is often associated with great technical difficulties and potentially hazardous consequences, such as cerebral complications, distal thromboembolism, and cardiac damage. Since the initial report on successful resection of the aortic arch,
1 several supportive techniques, such as hypothermic circulatory arrest and selective cerebral perfusion, 2,3 have been used in the surgical treatment of the aortic arch. However, these techniques have both advantages and drawbacks.
We have used a hypothermic total body retrograde perfusion technique in patients undergoing surgical treatment for Stanford type A aortic dissection. 4 This technique yields a relatively bloodless operating field and provides cold, oxygenated blood to the vital organs during the surgical procedure. On the basis of our experience, we have been able to apply the total body retrograde perfusion technique to the surgery of the aortic arch and the proximal descending thoracic aorta.
PATIENTS AND METHODS
Patients
Five consecutive patients were operated on between May 1991 and September 1992. Patients with aortic dissection were excluded from this series. The ages of the five adult male patients included in this study ranged from 26 to 70 years. The aneurysms were atherosclerotic in three patients, caused by vascular Behçet disease in one, and mycotic in nature in the remaining patient. An emergency operation was performed in three patients: two were in shock because of impending rupture before the operation and one had respiratory failure because of acute tracheal compression. The lesions were limited to the aortic arch in two patients, extensively involved the arch and cephalic arteries in one, arose just distal to the left subclavian artery in one, and arose on the distal aortic arch involving the left subclavian artery in one 5 (Table I).
|
6 and the pump flow was temporarily discontinued. The patient was positioned in a mild Trendelenburg position. Total body retrograde perfusion was then initiated. Venous drainage cannulas were switched over to the arterial circuit and cold oxygenated blood was pumped retrogradely through each vena cava.
In the first three patients, the superior vena caval cannula was placed in the usual position. In the latter two patients, the superior vena caval cannula was inserted further into the right internal jugular vein to provide adequate cerebral perfusion. 7 The perfusion flow rate in both venae cavae was maintained between 300 and 500 ml/min and the upper venous pressure was limited to 30 mm Hg. The temperature of the cold oxygenated blood during total body retrograde perfusion was maintained from 13° to 18° C (mean 16.5° C). Gas management was directed at maintaining a pH of 7.35 to 7.40, a carbon dioxide tension of 35 to 40 mm Hg, and an oxygen tension of more than 300 mm Hg, uncorrected for temperature. Simultaneously with the start of bicaval retrograde perfusion, the right atrium was opened, retrograde cardioplegia through the coronary sinus was accomplished, and wide excision of the aneurysm was performed. Cold blood cardioplegic solution was added every 20 minutes. The effluent blood from the total body returning through the aorta was sucked with a tube and drained into the oxygenator through the venous reservoir (Fig. 1). A relatively bloodless operative field was attainable.
|
|
|
|
|
No uncontrollable bleeding occurred after the operation. All patients awoke on the first postoperative day without sensory disturbances or convulsions. No neurologic sequelae, no problems with myocardial preservation, and no perioperative myocardial insults were detected. Laboratory data suggestive of abnormal renal and hepatic function were not observed, and no gastrointestinal complications were detected after the operation. In four patients, the postoperative course was uneventful. Only one patient (patient 3) died. This man had sepsis before the operation and died of massive hemorrhage caused by a mediastinal infection on the seventh postoperative day.
CPB time ranged from 170 to 310 minutes (mean 228 minutes), and total body retrograde perfusion time ranged from 34 to 95 minutes (mean 57 minutes). The lowest rectal temperature was from 17° to 20° C (mean 18.2° C) (Table II). Mean flows in the superior vena cava and the inferior vena cava during total body retrograde perfusion were 300 ml/min and 450 ml/min, respectively.
|
Blauth and associates 8 reported that the risk of atheroembolism during operations for valvular and ischemic heart disease has recently increased dramatically. They concluded that atheroembolic events were closely related to the presence of severe atherosclerosis of the aorta. Despite improvements in surgical skill and myocardial protection, cerebral injury has been a frequent complication, particularly in the form of cerebral infarction after clamping of the aorta. Clamping the aorta during operations on the aorta as well as during operations for acquired cardiac disease may result in atheroembolism. Because manipulation and clamping of the atherosclerotic aorta increases the possibility of releasing atheromatous debris, some techniques have been devised to minimize risk.
Several techniques including selective cerebral perfusion, conventional hypothermic circulatory arrest, and retrograde cerebral perfusion associated with hypothermic circulatory arrest have been used for operations on the aortic arch. 2,3,9 Although selective cerebral perfusion can provide unlimited time to perform the repair, it necessitates cannulation and clamping of both the aorta and the cephalic arteries. The cold cerebroplegia technique advocated by Bachet and coworkers 10 might be useful; however, atheroembolism is a concern with the cannulation technique, and problems are associated with dissection of the arch branches. Conventional hypothermic circulatory arrest can avoid the cannulation technique and provides a motionless and bloodless operative field. However, the risk of neurologic damage has been a major limitation. The safe duration of hypothermic circulatory arrest is from 45 to 60 minutes, and an increased frequency of neurologic complications becomes evident when the circulation is interrupted longer than 60 minutes. 11 In 1982, Althaus and colleagues 12 reported complete recovery from a longer period of total cardiopulmonary arrest resulting from accidental profound hypothermia. Three patients fully recovered their intellectual and physical abilities, despite circulatory interruption for over 120 minutes. This report suggests that the safe duration of hypothermic circulatory arrest might be much longer than 60 minutes if a temperature below 20° C in the brain and other vital organs were maintained. A temperature gradient among the organs may be generated, and the brain may not be kept as cold as the surgeon expects it to be in conventional hypothermic circulatory arrest with core cooling. In addition, body temperature may be influenced more or less by room temperature.
The total body retrograde perfusion technique that we developed is relatively simple and has two important advantages. One benefit is the ability to keep the body organs profoundly hypothermic to preserve their function. The other benefit is to avoid atheromatous emboli resulting from clamping of the aorta or development of air emboli, which occasionally occurs with circulatory arrest. The concept of retrograde perfusion through the venae cavae dates back to a report on the management of air embolism during CPB. 13 Temporary retrograde perfusion by way of the superior vena cava was carried out to remove air from the cerebrovascular bed. For massive air embolism, retrograde perfusion via both venae cavae was recommended. Lemole and associates 14 have applied this maneuver to implantation of the intraluminal sutureless graft for acute aortic dissection. Ueda and coworkers 9 have reported the replacement of the ascending aorta and aortic arch with the aid of hypothermic circulatory arrest with retrograde cerebral perfusion via the superior vena cava. This adjunct seems to be safer than conventional hypothermic circulatory arrest. However, we consider "partial" retrograde perfusion by way of only the superior vena cava to be inadequate to protect the brain. In Ueda's method, some controversy remains concerning protection of the brain. We recognized that blood flow through the superior vena cava must be increased to keep systemic venous pressure constant if the flow pumped from the inferior vena cava was decreased during hypothermic total body retrograde perfusion. On the basis of our experience, many veins connect the superior vena cava and the inferior vena cava. Therefore, the blood pumped retrogradely through the superior vena cava might be shunted to the lower part of the body via the azygos and other communicating veins and pooled in the abdominal organs. An experimental study in dogs demonstrated that blood perfused through the superior vena cava partially drained into the lower part of the body. 15 Oohara and associates 16 reported that retrograde perfusion through the inferior vena cava had a beneficial effect on the aerobic metabolism of the abdominal visceral organs. These studies suggest that retrograde perfusion through the inferior vena cava can prevent blood flow through the superior vena cava from stealing into the lower part of the body and can preserve the function of the vital organs in the abdomen.
In addition, the possibility remains that venous valves in the internal jugular vein impede retrograde flow through the superior vena cava and as a result the central nervous system may not be perfused adequately. To solve these anatomic impediments, we 7 developed the total body retrograde perfusion technique with selective cannulation into the right jugular vein. No significant differences were observed clinically between total body retrograde perfusion with and without selective cannulation in this small series. However, this modified total body retrograde perfusion technique is superior, because it is consistent with the fact that the veins in the brain have no valves and hence can overcome the pitfall of nonselective retrograde cerebral perfusion. The disadvantage of using profound hypothermia is prolonged CPB and resultant coagulopathy. However, the use of a coated graft with fibrin sealant can prevent uncontrollable bleeding, and hemorrhage caused by the hypothermic technique was not a serious problem in this series.
We conclude that the total body retrograde per fusion technique is a safe, excellent adjunct in the resection of aneurysms involving the aortic arch or adjacent areas.
References
This article has been cited by other articles:
|
|
 |
|
  C.-C. Chen and S.-R. Hsieh Successful salvage of inferior vena cava rupture during reoperative repair for ascending aortic aneurysm Ann. Thorac. Surg., February 1, 2004; 77(2): 715 - 718. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Ogino, Y. Ueda, T. Sugita, K. Matsuyama, K. Matsubayashi, T. Nomoto, and T. Yoshioka Aortic arch repairs through three different approaches Eur. J. Cardiothorac. Surg., January 1, 2001; 19(1): 25 - 29. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. V. Rao, R. F. Stahl, B. R. Soller, K. G. Shortt, C. Hsi, K. J. Cotter, J. M. BelleIsle, and J. M. Moran Retrograde Abdominal Visceral Perfusion: Is It Beneficial? Ann. Thorac. Surg., December 1, 1995; 60(6): 1704 - 1708. [Abstract] [Full Text]
|
|
|
|
|
|
J. E. Bavaria, Y. J. Woo, R. A. Hall, J. P. Carpenter, and T. J. Gardner Retrograde Cerebral and Distal Aortic Perfusion During Ascending and Thoracoabdominal Aortic Operations Ann. Thorac. Surg., August 1, 1995; 60(2): 345 - 352. [Abstract] [Full Text]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
