Asian Cardiovasc Thorac Ann 2005;13:337-340
© 2005 Asia Publishing EXchange Ltd
Arch Reconstruction without Circulatory Arrest in Neonates
Yuko Takeda, MD,
Toshihide Asou, MD,
Nobuyuki Yamamoto, MD,
Kuniyoshi Ohara, MD,
Hirokuni Yoshimura, MD,
Hirotsugu Okamoto, MD1
Department of Thoracic and Cardiovascular Surgery
1 Department of Anesthesiology, Kitasato University, School of Medicine, Kanagawa, Japan
For reprint information contact: Toshihide Asou, MD Tel: 81 45 711 2351 Fax: 81 45 742 7821 Email: surgeon{at}pf7.so-net.ne.jp, Department of Cardiovascular Surgery, Kanagawa Children’s Medical Center, Mutsukawa 2-138-4, Minami-ku, Yokohama, Kanagawa 232-8555, Japan.
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ABSTRACT
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Between May 2000 and December 2002, 10 neonates underwent arch reconstruction without circulatory arrest. Age at surgery ranged from 1 to 18 days, and body weight ranged from 1.62 to 3.38 kg. The diagnosis was interrupted aortic arch in 4, hypoplastic left heart syndrome in 3, and coarctation complex in 3. A 3 mm polytetrafluoroethylene graft was anastomosed to the innominate artery, and the brain was perfused via this graft while the aortic arch was reconstructed. Regional cerebral oxygen saturation and the right and left radial artery pressures were monitored. There were 2 deaths: one because of low cardiac output syndrome after a Norwood operation; another from multiple organ failure due to preoperatively undetected congenital biliary atresia. Regional cerebral oxygen saturation was kept constant at over 40% during regional cerebral perfusion. There were no neurologic sequelae observed postoperatively. It was concluded that the regional cerebral perfusion technique can be safely applied during neonatal aortic arch reconstruction, and deep hypothermic circulatory arrest should be avoided.
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INTRODUCTION
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Since the beginning of cardiac surgery, deep hypothermic circulatory arrest (DHCA) has been the only available modality for arch reconstruction in neonates.1 Neurologic sequelae have been reported to relate to DHCA following heart surgery in newborns.2–3 Although many meticulous bypass techniques designed to prevent acute neurologic events have been investigated, complications including seizures and coma continue even in the current era.4 Currently available sophisticated measurements of neurologic function have demonstrated the long-term detrimental effects of DHCA.2–3 These effects might be caused by the cessation of blood flow to the brain during cardiac surgery in neonates, thus blood flow must be maintained during the procedure. To this end, we developed a technique of selective cerebral perfusion or regional cerebral perfusion, which was first reported elsewhere in 1996.5 This report describes the outcome of aortic arch reconstruction using the selective cerebral perfusion technique in neonates at our institute.
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PATIENTS AND METHODS
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Between May 2000 and December 2002, 10 neonates underwent arch reconstruction without circulatory arrest at our institute. Ages ranged from 1 to 18 days, with a mean of 8.0 ± 5.5 days. Body weight ranged from 1.62 to 3.38 kg, with a median of 2.6 kg. There were 4 girls and 6 boys. Cardiac anomalies were interrupted aortic arch in 4, hypoplastic left heart syndrome in 3, and coarctation complex in 3. Preoperatively, prostaglandin E1 was used to open a patent ductus arteriosus through which to perfuse the body. The surgical procedures included a modified Norwood operation in 5 and arch reconstruction with biventricular repair in 5. The patients were anesthetized using fentanyl, diazepam and sevoflurane. A small probe for transesophageal echocardiography was placed in the last 5 patients. An arterial pressure line was inserted into the right radial artery. A second arterial pressure line was inserted into the left radial artery to detect the difference in perfusion pressure between the cerebral hemispheres. Regional brain oxygen saturation was monitored using near-infrared spectroscopy, preferably in the left hemisphere. Simultaneously, bispectral index monitoring was recorded to detect changes in electroencephalography. A midline sternotomy was performed and the pericardium was opened. The aortic arch and its branches were dissected. The descending aorta was also dissected as distally as possible. A 3 mm polytetrafluoroethylene (PTFE) graft was anastomosed to the innominate artery to perfuse the brain and myocardium during arch reconstruction, and the whole body after the arch repair (Figure 1
).5 Another cannula was inserted into the arterial duct to perfuse and cool the lower part of the body. In 3 cases, the lower part of the body was perfused through a cannula inserted into the descending aorta just above the diaphragm.6–8 Mild to moderate hypothermia was applied to maintain a rectal temperature of 30°C to 32°C during cardiopulmonary bypass (CPB). Pump flow was maintained at 150 to 180 mL·kg–1·min–1 using highflow CPB with alpha-stat strategy.9 Before repairing the arch, the cannula in the arterial duct was removed and clamps were applied to the aortic arch just distal to the innominate artery, the left common carotid artery, the left subclavian artery, and the descending aorta. Regional cerebral perfusion was commenced through the PTFE graft. The flow was adjusted to keep the left radial artery pressure at more than 30 mm Hg. Regional cerebral oxygen saturation was monitored in the left brain using near-infrared spectroscopy. When cerebral oxygen saturation decreased below 30%, either pump flow or blood temperature was adjusted. To maintain the hematocrit at approximately 30%, homologous blood was transfused in all patients. A modified ultrafiltration method was employed to increase the hematocrit just before weaning from CPB.
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Figure 1. Access to regional cerebral perfusion via a 3 mm PTFE graft anastomosed to the innominate artery. Desc Ao = descending aorta.
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The ductal tissue was completely removed and the descending aorta was anastomosed to the undersurface of the aortic arch during regional cerebral perfusion. The aortic arch was repaired with direct anastomosis when possible. In 2 patients undergoing a modified Norwood procedure, a glutaraldehyde-treated autologous pericardial roll was interposed between the main pulmonary artery and the aortic arch because of extremely rare anomalies. In these patients, there was a rather long distance between the proximal stump of the main pulmonary artery and the aortic arch, due to a right aortic arch with left-sided heart in one case, and dextrocardia with situs solitus in the other. Direct anastomosis was completed for aortic arch repair during regional cerebral perfusion in the other patients.10 After completion of the aortic arch repair, the clamps were removed and the pump flow was increased to resume whole-body perfusion. During cardioplegic arrest, intracardiac repair was performed for patch closure of a ventricular septal defect in 4 patients, with or without relief of subaortic stenosis, and repair of a complete atrioventricular defect in one. Atrial septectomy was achieved under a beating heart in 4 patients undergoing a modified Norwood operation under transesophageal echo-guidance to detect intracavity air bubbles.
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RESULTS
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The mean duration of CPB was 215 ± 75 min and the aortic crossclamp time was 47 ± 46 min. The minimal hematocrit level during CPB was 26.5 ± 2.5%. Pump flow during regional cerebral perfusion ranged from 30 to 90 mL·kg–1·min–1 to maintain left radial pressure above 30 mm Hg. The difference between the right and left radial artery pressures during regional cerebral perfusion was 10 to 20 mm Hg, which demonstrates a well-functioning circle of Willis in the brain . The mean right radial artery pressure was 53 ± 12 mm Hg and the left radial pressure was 42 ± 12 mm Hg during regional cerebral perfusion. The temperature of the arterial blood was 29.2 ± 2.7°C during regional cerebral perfusion. The regional cerebral oxygen saturation and the systemic venous oxygen saturation were kept constant at an ideal level with regional brain oxygen saturation over 40% during the whole procedure . The mean regional cerebral oxygen saturation was 57 ± 6%, and systemic venous oxygen saturation was 85 ± 8%.
There were 2 deaths. One patient died after a Norwood operation because of low cardiac output syndrome. Another patient with polysplenia syndrome including complete atrioventricular septal defect, interrupted inferior vena cava with hemiazygos connection, unroofed coronary sinus with left superior vena cava, and congenital complete atrioventricular block underwent arch reconstruction and biventricular repair and died of multiple organ failure due to preoperatively undetected congenital biliary atresia. There were no neurologic sequelae observed in any of the 8 survivors. They grew normally and developed uneventfully in the mean follow-up period of 3.2 ± 0.8 years, except for one patient who had VATER association (vertebral defects, anal atresia, tracheoesophageal fistula, renal defects and radial dysplasia) with subaortic stenosis. In this patient, left pulmonary stenosis later developed and a redo operation was performed. There was no recurrent coarctation or residual stenosis observed.
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DISCUSSION
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Although DHCA has greatly contributed to the progress in surgical treatment of complex cardiac defects, unfavorable long-term neurodevelopmental deficits have been well documented because of the sophisticated neurologic tests currently available.2,3,9–14 Many centers have meticulously investigated bypass techniques for DHCA to reduce the incidence of neurologic deficits.14–15 However, high incidences of neurologic events including seizures or coma are still being reported. Recently, Clancy and colleagues4 found that acute neurologic events occurred in 31 patients (18.9%) among 164 non-hypoplastic left heart syndrome survivors who underwent neonatal heart surgery using DHCA.
The optimal flow to the brain during regional cerebral perfusion has been controversial. We adopted pressure monitoring as a guide to cerebral blood flow because an experimental study showed that there is still autoregulation of cerebral blood flow during hypothermic CPB; that is, cerebral blood flow remains constant within a certain pressure range.16 We adjusted bypass flow during regional cerebral perfusion to maintain the left radial arterial pressure at more than 30 mm Hg. As a consequence, the bypass flow ranged from 30 to 90 mL·kg–1·min–1. The regional cerebral oxygen saturation of the left brain was monitored using near-infrared spectroscopy and maintained above 40%. These results demonstrated that the circle of Willis was functioning well, thus right hemisphere perfusion led to left hemisphere perfusion. However, the anatomy of the circle of Willis in each patient is not completely clear.17 Therefore, it is important to monitor perfusion to the left hemisphere during regional cerebral perfusion using near-infrared spectroscopy.
The temperature during regional cerebral perfusion seems to be important. We accepted a warmer temperature of 30°C to 32°C while perfusing the left hemisphere which was carefully monitored for arterial pressure and regional cerebral oxygen saturation. When regional cerebral saturation decreased below 30%, the body was cooled to 28°C. None of the patients in our series showed any neurologic sequelae. Considering the adverse effects of deep hypothermia, such as coagulopathy and capillary leakage, mild hypothermia with this technique may improve the surgical results. Thus, a temperature range of 30°C to 32°C is recommended during regional cerebral perfusion.
Although many centers have investigated CPB techniques during DHCA to limit brain ischemia during complex cardiac repair, we believe that the best option is to avoid circulatory arrest altogether. There is no doubt that maintaining cerebral perfusion is advantageous. In our view, there is no safe duration of circulatory arrest. However, some may be discouraged by the complexities of our technique and the monitoring system for brain perfusion. It might be convenient to use a thin-walled flexible arterial cannula for brain perfusion, as reported by one of the authors, rather than a PTFE graft anastomosed to the brachiocephalic artery.18 Regarding the monitoring system, it might be sufficient to monitor either right or left radial artery pressure, because the results show the rather constant pressure difference between both sides of the upper extremity during regional cerebral perfusion. Since this difference was approximately 10 mm Hg, the CPB flow could be regulated by estimating the pressure of the opposite hemisphere on the basis of this value of pressure difference.
It was concluded that the technique described herein avoided neurologic complications following arch reconstruction in neonates by preventing ischemic injury of the brain. Arch reconstruction can be safely performed without circulatory arrest in neonates using this technique.
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ACKNOWLEDGMENTS
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The authors would like to express their gratitude to Mr. Satoru Kohira, Mr. Keiichi Todo, and Mr. Atsushi Nishikawa in the Medical Engineering Center in Kitasato University for their great contribution to the present technique in arch reconstruction in neonates.
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REFERENCES
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- Barratt-Boyes BG, Nicholls TT, Brandt PW, Neutze JM. Aortic arch interruption associated with patent ductus arteriosus, ventricular septal defect, and total anomalous pulmonary venous connection. Total correction in an 8-day-old infant by means of profound hypothermia and limited cardiopulmonary bypass. J Thorac Cardiovasc Surg 1972;63:367–73.[Medline]
- Newburger J, Jonas RA, Wernovsky G, Wypij D, Hickey PR, Kuban KC, et al. A comparison of the perioperative neurologic effects of hypothermic circulatory arrest versus low-flow cardiopulmonary bypass in infant heart surgery. N Engl J Med 1993;329:1057–64.[Abstract/Free Full Text]
- Bellinger DC, Jonas RA, Rappaport LA, Wypij D, Wernovsky G, Kuban KC, et al. Developmental and neurologic status of children after heart surgery with hypothermic circulatory arrest or low-flow cardiopulmonary bypass. N Engl J Med 1995;332:549–55.[Abstract/Free Full Text]
- Clancy RR, McGaurn SA, Wernovsky G, Gaynor JW, Spray TL, Norwood WI, et al. Risk of seizures in survivors of newborn heart surgery using deep hypothermic circulatory arrest. Pediatrics 2003;111:592–601.[Abstract/Free Full Text]
- Asou T, Kado H, Imoto Y, Shiokawa Y, Tominaga R, Kawachi Y, et al. Selective cerebral perfusion technique during aortic arch repair in neonates. Ann Thorac Surg 1996;61:1546–8.[Abstract/Free Full Text]
- Imoto Y, Kado H, Shiokawa Y, Fukae K, Yasui H. Norwood procedure without circulatory arrest. Ann Thorac Surg 1999;68:559–61.[Abstract/Free Full Text]
- Imoto Y, Kado H, Shiokawa Y, Minami K, Yasui H. Experience with the Norwood procedure without circulatory arrest. J Thorac Cardiovasc Surg 2001;122:879–82.[Abstract/Free Full Text]
- Cooley DA. Cannulation for temporary bypass. In: Cooley DA, editor. Techniques in cardiac surgery. 2nd ed. Philadelphia: W.B. Saunders, 1984:83–97.
- Poirier NC, Drummond-Webb JJ, Hisamochi K, Imamura M, Harrison AM, Mee RB. Modified Norwood procedure with a high-flow cardiopulmonary bypass strategy results in low mortality without late arch obstruction. J Thorac Cardiovasc Surg 2000;120:875–84.[Abstract/Free Full Text]
- Fraser CD Jr, Mee RB. Modified Norwood procedure for hypoplastic left heart syndrome. Ann Thorac Surg 1995;60(6 Suppl):S546–9.
- Yasui H, Kado H, Yonenaga K, Kawasaki S, Shiokawa Y, Kouno H, et al. Revised technique of cardiopulmonary bypass in one-stage repair of interrupted aortic arch complex. Ann Thorac Surg 1993;55:1166–71.[Abstract]
- Pawade A, Waterson K, Laussen P, Karl TR, Mee RB. Cardiopulmonary bypass in neonates weighing less than 2.5 kg: analysis of the risk factors for early and late mortality. J Card Surg 1993;8:1–8.[Medline]
- Reddy VM, McElhinney DB, Sagrado T, Parry AJ, Teitel DF, Hanley FL. Results of 102 cases of complete repair of congenital heart defects in patients weighing 700 to 2500 grams. J Thorac Cardiovasc Surg 1999;117:324–31.[Abstract/Free Full Text]
- Visconti KJ, Bichell DP, Jonas RA, Newburger JW, Bellinger DC. Developmental outcome after surgical versus interventional closure of secundum atrial septal defect in children. Circulation 1999;100(19 Suppl):II145–50.
- du Plessis AJ, Jonas RA, Wypij D, Hickey PR, Riviello J, Wessel DL, et al. Perioperative effects of alpha-stat versus pH-stat strategies for deep hypothermic cardiopulmonary bypass in infants. J Thorac Cardiovasc Surg 1997;114:991–1001.[Abstract/Free Full Text]
- Tanaka J, Shiki K, Asou T, Yasui H, Tokunaga K. Cerebral autoregulation during deep hypothermic nonpulsatile cardiopulmonary bypass with selective cerebral perfusion in dogs. J Thorac Cardiovasc Surg 1988;95:124–32.[Abstract]
- Riggs HE, Rupp C. Variation in form of circle of Willis. The relation of the variations to collateral circulation: anatomic analysis. Arch Neurol 1963;8:8–14.
- Asou T, Yasui H, Kado H, Imoto Y, Shiokawa Y, Fukae K, et al. The use of a newly developed pediatric arterial perfusion cannula for neonates. Cardiol Young 1997;7:71–3.
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ABSTRACT
INTRODUCTION
