Norwood procedure without circulatory arrest.

In the Norwood procedure for hypoplastic left heart yndrome, the distal descending thoracic aorta was cannulated just superior to the diaphragm through median sternotomy. In combination with cerebral perfusion through the graft anastomosed to the innominate artery, which was used as a systemic-to-pulmonary shunt later, this technique enabled us to completely avoid circulatory arrest and deep hypothermia throughout the operation.     

Norwood operation without circulatory arrest: a new surgical technique

Circulatory arrest (CA) is associated with potential neurologic injury. We have developed a new surgical technique to eliminate CA during the Norwood operation. A modified Blalock-Taussig shunt (BTS) was fully constructed before cannulation for cardiopulmonary bypass. The aortic cannula was inserted in the patent ductus arteriosus to allow systemic cold perfusion. When deep hypothermia was reached, the aortic cannula was redirected into the pulmonary artery (PA) confluence. Both cerebral and systemic perfusion were maintained through the right PA and BTS into the innominate artery.     

Stage 1 palliation for hypoplastic left heart syndrome without the use of allogeneic tissue, with reduced allogeneic blood product exposure: a case report

In the 30 years since Norwood described the palliative procedure for hypoplastic left heart syndrome (HLHS), many modifications have been described which have increased the survival rate of children born with this lesion. We describe further modifications which result in reduced cardiopulmonary bypass time, no cooling or circulatory arrest time, and decreased banked blood exposure. A 16-day-old infant with HLHS undiagnosed during pregnancy presented for stage 1 palliation incorporating the Mee modification, Sano right ventricle to pulmonary artery conduit, dual arterial cannulation of the innominate artery and descending aorta, single venous cannulation of the right atrium, and a bypass prime volume of 130 mL. Anticoagulation and hemostasis were monitored with the Hepcon HMS Plus Hemostasis Management System (Medtronic USA, Minneapolis, MN). Bypass commenced at normothermia. A 5.0 Gore-Tex shunt was placed for the Sano Shunt, and the aortic arch was repaired without use of homologous tissue or synthetic material using a modification of the Mee technique. Bypass time was 92 minutes with a 10 minutes cardiac ischemic time. Modified ultrafiltration (MUF) was performed for 12 minutes and heparinization was reversed with protamine. There was no significant bleeding and no indication to transfuse clotting factors. The patient's only allogeneic donor exposure was 350 mL of red blood cells during bypass necessary to achieve a post MUF hematocrit of 50% per our current institution policy for cyanotic infants. Using modified surgical and perfusion techniques along with low prime bypass circuits can result in reduced cross clamp and bypass times as well as a decrease in blood donor exposure. Hypothetical benefits include reduced operating room, ventilation, intensive care unit, and hospital times, improved neurodevelopmental outcomes, and an overall reduction in the cost of care for infants with HLHS.     

Neonatal aortic arch reconstruction avoiding circulatory arrest and direct arch vessel cannulation.

BACKGROUND: Aortic arch reconstruction in neonates routinely requires deep hypothermic circulatory arrest. We reviewed our experience with techniques of continuous low-flow cerebral perfusion (LFCP) avoiding direct arch vessel cannulation. METHODS: Eighteen patients, with a median age of 11 days (range 1 to 85 days) and a mean weight of 3.2 +/- 0.8 kg, underwent aortic arch reconstruction with LFCP. Seven had biventricular repairs with arch reconstruction, 9 underwent the Norwood operation and 2 had isolated arch repairs. In 1 Norwood and 7 biventricular repair patients, LFCP was maintained by advancing the cannula from the distal ascending aorta into the innominate artery. In 8 of 9 Norwood patients, LFCP was maintained by directing the arterial cannula into the pulmonary artery confluence and perfusing the innominate artery through the right modified Blalock-Taussig shunt fully constructed before cannulation for cardiopulmonary bypass. In 2 patients requiring isolated arch reconstruction, the ascending aorta was cannulated and the cross-clamp was applied just distal to the innominate artery. RESULTS: LFCP was maintained at 0.6 +/- 0.2 L x min(-1) x m(-2) for 41.0 +/- 13.9 minutes at 18.5 degrees C +/- 1.1 degrees C. In 10 of the 18 patients, blood pressure during LFCP was 15 +/- 8 mm Hg remote from the innominate artery (left radial, umbilical or femoral arteries). In 8 of the 18 patients, right radial pressure during LFCP was 24 +/- 10 mm Hg. The mean mixed-venous saturation was 79.8% +/- 10% during LFCP. Two patients had preoperative seizures, whereas none had seizures postoperatively. One patient died. CONCLUSIONS: Neonatal aortic arch reconstruction is possible without circulatory arrest or direct arch vessel cannulation. These techniques maintained adequate mixed-venous oxygen saturations with no associated adverse neurologic outcomes.     

Moderately hypothermic cardiopulmonary bypass and selective cerebral perfusion in ascending aorta and aortic arch surgery. Preliminary experience in twenty-two patients

Deep hypothermic cardiocirculatory arrest is the commonest method of brain protection during transverse aortic arch surgery. Its principle drawbacks consist in the limited safe ischemic period and in the coagulative, renal and pulmonary complications related to low body temperatures and prolonged cardiopulmonary bypass time. Different selective cerebral perfusion techniques have recently raised the interest of some surgical teams in an effort to obviate these problems. The authors' initial experiences with 22 patients, ranging in age from 19 to 78 years (mean, 55±15 years), who underwent ascending aorta and/or aortic arch replacement using selective cerebral perfusion and moderately hypothermic cardiopulmonary bypass are reported here. Acute aortic dissection and atherosclerotic aneurysm were the commonest lesions observed: ascending aorta associated with partial or complete arch replacement was the most widely performed procedure. With regard to the perfusion technique, after regular cardiopulmonary bypass had been established through the iliac vessels, selective cerebral perfusion was started after aortic arch vessels cannulation (innominate artery, bilateral common carotid artery, innominate artery and left common carotid artery, or right common carotid artery) using a single roller pump separately from the systemic circulation, and brain perfusion was achieved by blood cooled at 30°C, at a flow rate that ranged from 300 ml/min to 1500 ml/min, at a perfusion pressure of ~65 mmHg, with the patient maintained at moderate hypothermia (30°C rectal). To perform distal aortic repair, if transverse aortic arch or proximal descending aorta cross-clamping was not feasible, cardiopulmonary bypass flow was lowered to 300–350 ml/min and an open anastomosis was performed, while independently assuring cerebral perfusion (six patients). There were three hospital deaths (mortality rate of 13.6%; s.d. 6.0–25.5%; 70% confidence limit), but none because of cerebral accident. No paraplegia occurred. One patient suffered from right hemiparesis, neither renal nor pulmonary complications were observed. Two chest reexplorations were necessary for bleeding, which were partially related to hemocoagulative disorders. In our experience, the technique of moderately hypothermic cardiopulmonary bypass and selective cerebral perfusion in aortic surgery has provided good results with regard to cerebral protection and organ function preservation. Therefore, allowing a prolonged distal aortic reconstruction period, it may be considered as a safe alternative to profound hypothermia associated with cardiocirculatory arrest in aortic arch surgery.     

Arch reconstruction without circulatory arrest: Scientific basis for continued use and application to patients with arch anomalies

Aortic arch hypoplasia is a common constituent of congenital heart disease. While repair of these lesions has been performed routinely during deep hypothermia and circulatory arrest, new approaches are emerging. One such approach, regional low-flow perfusion, will be described here. This technique exploits the anticipated modified Blalock-Taussig shunt as a perfusion conduit. With control of the brachiocephalic vessels and the descending thoracic aorta, circulatory support can be provided to the neonate with exposure identical to that obtained by circulatory arrest. While first applied to children undergoing the Norwood operation for hypoplastic left heart syndrome, this technique has recently been applied to children requiring complex arch surgery in the setting of biventricular repair. To date, 36 neonates requiring arch reconstruction (27 Norwood operations, 9 biventricular repairs) have been supported with regional low-flow perfusion. Thirty-day and hospital discharge survival has been 74% (20/27) for neonates undergoing Norwood operation, and 88% (8/9) for those undergoing biventricular repair. We will review the operative technique, methodologies, and clinical studies that led us to conclude that regional low-flow perfusion provides cerebral, as well as somatic, circulatory support to the neonate undergoing arch reconstruction. Copyright © 2002 by W.B. Saunders Company     

Aortic arch reconstruction without circulatory arrest: Review of techniques,applications, and indications

The majority of neonatal intracardiac repairs can now be performed with the use of low-flow cardiopulmonary bypass. However, aortic arch reconstruction still requires a period of circulatory arrest. Recently, a number of surgeons have reported techniques of limiting or completely avoiding circulatory arrest during arch reconstruction in an attempt to reduce the risk of neurologic injury. Several techniques are currently in use that have been successfully applied during biventricular repair and the Norwood operation for a wide range of aortic arch pathology including hypoplastic or interrupted aortic arch, the hypoplastic left heart syndrome, and its equivalents. These techniques maintain continuous low-flow cerebral perfusion via the innominate artery, directly or indirectly. In the last 2 years at the Montreal Children's Hospital (Montreal, Canada) we have consistently used such techniques for all arch reconstructions, including the Norwood operation, completely avoiding the use of circulatory arrest. These techniques are still in evolution with regard to flow rates, temperature, and safe period of low flow. Although the early results are encouraging, long-term follow-up with respect to neurodevelopmental outcome is essential to help us decide which techniques are optimal. This chapter provides an overview of the currently used techniques allowing cerebral perfusion during aortic arch reconstruction and summarizes our early experience at the Montreal Children's Hospital. Copyright © 2002 by W.B. Saunders Company     

Effect of deep hypothermia on cerebral hemodynamics during selective cerebral perfusion with systemic circulatory arrest

OBJECTIVE: We studied the effect of deep hypothermia on cerebral hemodynamics during selective cerebral perfusion with systemic circulatory arrest. METHODS: Ten anesthesized pigs were placed on cardiopulmonary bypass and cooled to a rectal temperature of 22 degrees C (n = 5) or 15 degrees C (n = 5). During selective cerebral perfusion, the descending aorta was clamped and perfusion of the lower body was discontinued. As the pump flow was changed, we monitored the perfusion pressure, local cerebral blood flow, and local cerebral oxygenation using laser Doppler flowmetry and near-infrared spectroscopy. We also measured the free flow of the left internal thoracic artery during selective cerebral perfusion. RESULTS: Perfusion pressure and local cerebral blood flow decreased as the pump flow decreased. Oxygenated and deoxygenated hemoglobin in cerebral tissue remained unchanged at a perfusion flow of 10 ml/kg/min, whereas oxygenated hemoglobin decreased and deoxygenated hemoglobin increased progressively and reciprocally as the pump flow decreased. The pump flow for maintaining perfusion pressure above 35 mmHg with stabilized local cerebral oxygenation was significantly higher at 15 degrees C than at 22 degrees C. The internal thoracic artery free flow was higher at 15 degrees C than at 22 degrees C. CONCLUSIONS: Selective hypothermic cerebral perfusion with systemic circulatory arrest produces an extracranial shunt through the internal thoracic artery, especially under deep hypothermia. Our data suggests that selective cerebral perfusion during deep hypothermia is best managed by perfusion pressure control rather than by flow control.     

Simultaneous selective cerebral perfusion and systemic circulatory arrest through the right axillary artery for aortic surgery

The duration of safe circulatory arrest for replacement of the ascending aorta for a type A dissection, without additional cerebral perfusion measures, is not clearly defined. If prolonged periods (> 60 minutes) are anticipated, retrograde cerebral perfusion or selective antegrade carotid perfusion may be required. The latter requires separate cannulas with subsequent snaring of the cerebral vessels, which may be time consuming and cumbersome. We propose an alternative method whereby the right axillary artery is cannulated for cardiopulmonary bypass and, when the desired hypothermic temperature is achieved, the flows are turned down to 500 mL/min. The origin of the innominate artery is then occluded establishing selective antegrade right carotid artery perfusion. The distal ascending or aortic arch anastomosis is then performed while the remainder of the body is under selective systemic circulatory arrest. The proximal aortic anastomosis is performed after the graft is clamped proximally and flows return to appropriate perfusion levels.     

Changes in cerebral and somatic oxygenation during stage 1 palliation of hypoplastic left heart syndrome using continuous regional cerebral perfusion

OBJECTIVES: Stage 1 palliation of hypoplastic left heart syndrome requires the interruption of whole-body perfusion. Delayed reflow in the cerebral circulation secondary to prolonged elevation in vascular resistance occurs in neonates after deep hypothermic circulatory arrest. We examined relative changes in cerebral and somatic oxygenation with near-infrared spectroscopy while using a modified perfusion strategy that allowed continuous cerebral perfusion. METHODS: Nine neonates undergoing stage 1 palliation for hypoplastic left heart syndrome had regional tissue oxygenation continuously measured by frontal cerebral and thoraco-lumbar (T10-L2) somatic (renal) reflectance oximetry probes (rSO(2), INVOS; Somanetics, Troy, Mich). Surgery was accomplished using cardiopulmonary bypass with whole-body cooling (18 degrees C-20 degrees C) and regional cerebral perfusion through the innominate artery at flow rates guided by estimated minimum flow requirements and measured rSO(2) during reconstruction of the aortic arch. Data were logged at 1-minute intervals and analyzed using repeated measures analysis of variance. RESULTS: A total of 3176 minutes of data were analyzed. Prebypass cerebral rSO(2) was 65.4 +/- 8.9, and somatic rSO(2) was 58.9 +/- 12.4 (P <.001, cerebral vs somatic). During regional cerebral perfusion, cerebral rSO(2) was 80.7 +/- 8.6, and somatic rSO(2) was 41.4 +/- 7.1 (P <.001). Postbypass cerebral rSO(2) was 53.2 +/- 14.9, and somatic rSO(2) was 76.4 +/- 7.7 (P <.001). The risk of cerebral desaturation was significantly increased after cardiopulmonary bypass. CONCLUSIONS: Cerebral oxygenation was maintained during regional cerebral perfusion at prebypass levels with deep hypothermia. However, after rewarming and separation from cardiopulmonary bypass, cerebral oxygenation was lower compared with prebypass or somatic values. These results indicate that cerebrovascular resistance is increased after deep hypothermic cardiopulmonary bypass, even with continuous perfusion techniques, placing the cerebral circulation at risk postoperatively.     

Air in the Aorta: Treatment by Reversed Perfusion

A ventricular septal defect was repaired in a 3 1/2-year-old child on cardiopulmonary bypass. Because of excessive pulmonary venous return, a period of circulatory arrest under deep hypothermia was used. A large volume of air was found in the arterial line and the ascending aorta before perfusion was reinstituted. The air probably entered the arterial system through a large aortopulmonary collateral artery during circulatory arrest. This artery was not visualized on angiocardiography and could have caused excessive pulmonary venous return during perfusion. Air was successfully expelled by reversed perfusion. There were no neurological sequelae.     

Single-stage repair of aortic coarctation with ventricular septal defect using isolated cerebral and myocardial perfusion.

OBJECTIVE: To avoid hypothermic circulatory arrest, we have repaired aortic coarctation with ventricular septal defect (VSD) in a one-stage procedure using an isolated cerebral and myocardial perfusion technique, and retrospectively compared this novel approach to the conventional two-stage approach. METHODS: Between October 1991 and February 1999, 24 infants, aged 4-137 days (median, 27 days) and weighing 1.7-4.3 kg (median, 3.0 kg), underwent the repair of aortic coarctation with VSD either in one (group I, n=11) or two stages (group II, n=13). In Group I, an arterial cannula for cardiopulmonary bypass was inserted into the ascending aorta in six patients with coarctation only, or into a polytetrafluoroethylene (PTFE) graft which was anastomosed to the innominate artery in the remaining five who had hypoplastic arches. A cross-clamp was placed between the innominate and left carotid arteries. The bypass flow was reduced to 30-50% of full flow at 28 degrees C, thereby maintaining a radial artery pressure of 30-45 mmHg. At this point, the aortic coarctation was repaired by an end-to-end arch anastomosis, while maintaining brain perfusion and with the heart still beating. In five patients with hypoplastic aortic arches, the innominate artery proximal to the graft was then secured down and the arch anastomosis was extended to the distal ascending aorta, while providing isolated cerebral perfusion and cardioplegic arrest. After arch reconstruction was performed, the clamp was moved onto the ascending aorta, and the VSD was closed with systemic perfusion. In contrast, for group II patients, coarctation repairs were performed through a posterolateral approach, and existing VSDs were closed as secondary procedures. RESULTS: The mean isolated cerebral and myocardial perfusion time for group I was 13 min (range, 7-20 min). The myocardial ischemic time did not differ between groups I and II (43+/-4 vs. 42+/-5 min, not significant). There were no hospital mortalities or neurological complications in either group, but one late death in each group. CONCLUSION: Single-stage repair of aortic coarctation with VSD does not increase myocardial ischemic time compared to the traditional two-stage approach. The isolated cerebral and myocardial perfusion technique may offer substantial brain and myocardial protection during aortic arch reconstruction.     

Surgical treatment of hypoplastic left heart syndrome: a successful case report

A successful case of Norwood operation for a 5-day-old infant with hypoplastic left heart syndrome is reported. Norwood procedure and central shunting with a 4 mm PTFE tube was performed. Cerebral and coronary artery were perfused independently during reconstruction of aorta in order to shorten the time of circulatory arrest. Post operative UCG documented un-obstructive systemic output from the right ventricle, well regulated pulmonary arterial blood flow and widely patent interatrial communication. This baby was discharged the hospital 66 days after surgery. He has been clinically well for six month after the operation.     

Off-pump aortic arch repair through a median sternotomy for type B interrupted aortic arch with single ventricle physiology

BACKGROUND: The aortic arch repair for interrupted aortic arch (IAA) with the hypoplastic ascending aorta through a median sternotomy requires cardiopulmonary bypass (CPB), which is very invasive in neonates and complicates pulmonary artery banding (PAB) is staged repair. METHODS: A 22-day-old neonate with a type B IAA having a functional single ventricle underwent arch repair and PAB through a median sternotomy without CPB. A partial occlusion clamp could be placed on the ascending aorta without cerebral malperfusion and the descending aorta could be directly anastomosed to the ascending aorta in an end-to-side fashion under stable circulatory condition. Thereafter, the tight PAB was performed with a circumference of 23mm without any difficulty. RESULTS: The postoperative echocardiogram revealed no stenosis on the anastomotic site and the patient was discharged uneventfully. CONCLUSION: This approach is effective in neonates with IAA who require staged repair, and least invasive for them.     

Limiting circulatory arrest using regional low flow perfusion

Deep hypothermic circulatory arrest (DHCA) is commonly used for neonatal cardiac surgery. However, prolonged exposure to DHCA is associated with neurologic morbidity. The Norwood operation and aortic arch advancement are procedures that typically require DHCA during surgical correction. Regional low flow perfusion (RLFP) can be used to limit or exclude the use of circulatory arrest. This technique involves cannulation of the innominate or subclavian artery using a Gore-Tex graft, allowing isolated cerebral perfusion. Data was collected in 34 patients undergoing either neonatal aortic arch reconstruction or the Norwood procedure using RLFP. All patients had two arterial pressure monitors using either the umbilical or femoral artery catheters and radial or brachial catheters. Adequacy of perfusion was determined using cerebral saturation, blood flow velocity, mean arterial pressures, and arterial blood gas results. Cerebral saturation and blood flow velocity were monitored using the near-infrared spectroscopy (NIRS) (INVOS 5100, Somanetics Corp, Troy, MI) and a transcranial Doppler pulse-wave ultrasound (TCD) (EME Companion, Nicolet Biomedical, Madison, WI), respectively throughout the entire bypass period. Blood gases were monitored using a point of care blood gas analyzer (Gem Premier, Mallinckrodt Sensor System, Inc., Ann Arbor, MI). Data collected revealed total bypass times for repair between 69-348 min, with a mean of 180 min. Regional low flow perfusion times lasted between 6-158 min, with an average of 50 min., and DHCA times ranged from 0-66 min, with a mean of 19 min. The perfusion techniques used allowed patient clinical data to remain consistent throughout the cardiopulmonary bypass period, regardless of lower flows (Figure 1) The 30-day postoperative mortality rate was 2.9 %, with no evidence of neurologic injury during follow up. In conclusion, regional low flow cerebral perfusion might benefit patients by limiting the use of circulatory arrest during cardiac surgery. Further study is necessary to evaluate patient outcomes, comparing regional cerebral perfusion and circulatory arrest techniques.     

自体肺动脉补片主动脉弓成形治疗婴儿主动脉缩窄合并弓发育不良

目的 探讨缩窄段切除加自体肺动脉补片主动脉弓成形治疗婴儿主动脉缩窄合并主动脉弓发育不良的方法和效果.方法 2007年5月至2009年12月,14例主动脉缩窄合并主动脉弓发育不良病婴行主动脉缩窄段切除加自体肺动脉补片主动脉弓成形手术,其中男9例,女5例;年龄23天至17个月,中位值4.33月龄;平均体重(6.14±2.36)kg.所有病婴均诊断为合并室间隔缺损的主动脉缩窄,同时存在主动脉弓发育不良.手术在深低温体外循环下完成,其中8例采用选择性脑灌注技术,6例停循环.主动脉成形采用新鲜的自体肺动脉补片.同期修补合并的室间隔缺损.结果 围术期死于循环衰竭1例.13例生存,其中1例合并低心排血量综合征,经相应治疗恢复.术后超声心动图检查主动脉弓无残余梗阻.随访4个月至3年.超声心动图示主动脉弓压力阶差均<16 mm Hg(1 mm Hg=0.133 kPa),随访期间主动脉弓降部血流速度与出院时无明显变化.CT扫描显示主动脉弓几何构形正常;术后半年原左主支气管受压者症状明显改善或完全消失.无主动脉夹层动脉瘤发生.结论 缩窄段切除加自体肺动脉补片主动脉弓成形是治疗婴儿主动脉缩窄合并主动脉弓发育不良理想的手术方法.

Abstract：

Objective To discuss the operative techniques and results of coarctation resection plus aortoplasty with pulmonary autograft patch for coarctation of the aorta combined with hypoplastic aortic arch in infant.Methods Between May 2007 and Dec 2009,14 cases including 9 males and 5 females with caorctation of the aorta and hypoplastic aortic arch underwent coarctation resection plus aortoplasty with pulmonary autograft patch in our hospital.The age ranged from 23 days to 17 months,with a median of 4.33 months.The mean body weight was (6.14 ±2.36) kg.All patients were diagnosed as aortic coarctation combined with VSD and hypoplastic aortic arch.The surgery was performed under deep hypothermia cardiopulmonary bypass with selective cerebral perfusion in 8 cases and circulation arrest in 6 cases.Fresh pulmonary autograft patch harvested from the main pulmonary artery was used for aortoplasty.The associated VSD was repaired in the same stage.Results All patients survived except one died from circulatory failure during the perioperative period.Low cardiac output syndrome occurred in another case who was cured afterwards by correspondent treatments.No residual obstruction was detected by echocar-diography after the operation.Follow-up was carried out in 13 cases from 4 months to 3 years.Echocardiographic examination showed that the pressure gradient across the aortic arch was less than 16 mm Hg in all cases.The blood velocity at the descending aortic arch was not significantly changed during the follow-up period as compared with that of the immediate after operation.Computed tomography showed that the morphology of aortic arch was normal.The left bronchus compression was relieved obviously or totally disappeared in patients who suffered from left bronchus stenosis before operation,and no aortic aneurysm were detected in these patients.Conclusion Conclusion Coarctation resection plus aortoplasty with pulmonary autograft patch is the optimal surgical method for treating coarctation of the aorta combined with hypoplastic aortic arch in infant.     

Aortic arch and proximal supraaortic arterial repair under continuous antegrade cerebral perfusion and moderate hypothermia.

PURPOSE: In this prospective study the clinical and neurological outcome of continuous antegrade cerebral perfusion (ACP) and moderate hypothermia was evaluated in patients undergoing ascending and aortic arch repair including reconstruction of the proximal supraaortic arteries. METHODS: In 50 consecutive patients (mean age 47 yr, range 22-70) aortic arch and supraaortic arterial repair was performed: ascending aorta and aortic arch (n=34) and aortic arch and Bentall procedure (n = 16). In 12 patients the distal anastomosis was performed using the elephant trunk technique. Test-clamping of the innominate artery for 3 min was performed under EEG-monitoring followed by the same procedure for the left carotid artery. Cardiopulmonary bypass was instituted and the innominate artery replaced by a polyester graft before antegrade perfusion was carried out through the graft. While cooling to 28-30 degrees C, the left carotid artery was similarly treated with subsequent antegrade cerebral perfusion. The distal anastomosis was made at or beyond the left subclavian artery under circulatory arrest. During rewarming the innominate and carotid polyester grafts as well as the subclavian artery were anastomosed to the main graft, while antegrade cerebral perfusion was continued. RESULTS: In 46 patients antegrade cerebral perfusion was achieved with a mean volume flow of 12 ml/kg/min and a mean arterial pressure of 54 mmHg. EEG-monitoring delineated stable and symmetrical recordings. In four patients antegrade flow (mean 15 ml/kg/min) and pressure (mean 65 mmHg) had to be increased to establish baseline EEG-recordings. The mean time of circulatory arrest was 18 min.The overall hospital mortality was 6%: two patients died from cerebral infarction and one patient suffered from a ruptured abdominal aortic aneurysm. Three patients (6%) developed a temporary neurological deficit which resolved spontaneously. Two patients (4%) developed renal failure requiring temporary hemodialysis. Pulmonary complications occurred in 12 patients (25%). CONCLUSION: Continuous antegrade cerebral perfusion via selective grafts to the innominate and carotid arteries offers adequate protection in patients undergoing replacement of the ascending aorta or aortic arch and great vessels. This technique allows radical repair and optimal vascular reconstruction without time restrains and avoids the necessity for profound hypothermia     

Techniques of aortic arch replacement: profound hypothermia versus moderate hypothermia with innominate artery perfusion

Aortic arch resection remains a challenging problem. At present, the most reliable technique appears to be profound hypothermia and circulatory arrest, although long cardiopulmonary bypass times and coagulopathy remain significant problems. Interest in alternative procedures continues. Herein, we report our experience of aortic arch replacement in eight patients using profound hypothermia (12 to 17 degrees C) and circulatory arrest in six patients (Group I) and moderate (20 degrees C) hypothermia with low flow (200 ml/min), pressure-monitored (100 mm Hg) innominate artery perfusion by way of a 14 Ga. cannula in 2 (Group II). Arch repair was by patch graft in two, and tube graft in six. Concomitant ascending aortic replacement was performed in five, aortic valve replacement in four, and coronary bypass in two. Circulatory arrest times ranged from 15 to 71 minutes in Group I and were 15 minutes and 35 minutes in Group II. All patients survived. One patient in Group I had a neurologic injury of moderate severity, probably due to a hypoxic postoperative cardiac arrest. We have found low flow pressure-monitored innominate artery perfusion and moderate hypothermia to be simple and expedient, and we will continue use of this technique.     

Factors influencing early outcome of Norwood procedure for hypoplastic left heart syndrome.

OBJECTVIE: The operative outcome of the Norwood procedure for hypoplastic left heart syndrome is still not satisfactory. Conflicting reports concern factors associated with early Norwood procedure mortality and the reasons for the instability after surgery are not sufficiently understood. The purpose of this study was to determine some perioperative factors influencing early (30 days) outcome. METHODS: We retrospectively analyzed a group of 30 consecutive children with hypoplastic left heart syndrome (aged 5-39 days) who underwent Norwood procedure in 1997 and 1998. The following factors were considered and statistically analyzed: operative age, birth weight, operative weight, serum level of bilirubin, aminotransferases, creatinine, urea, arterial blood gasses, anatomic subgroups, ascending aorta and arch size, systemic to pulmonary modified right Blalock-Taussig shunt size, cardiopulmonary circulatory arrest time, cardiopulmonary bypass time, and delayed chest closure. Eighteen patients underwent hemi-Fontan procedure with one late death and the modified Fontan operation was performed in 16 of them (one late death). RESULTS: The early mortality was 37%. Seven deaths (64%) occurred during the first 24 h after operation. There was a significant difference between survivals and non-survivals in: birth weight (P=0.047), operative age (P=0.016), preoperative serum level of bilirubin (P=0.044), and cardiopulmonary circulatory arrest time (P=0.006). The other assessed factors were not found to be predictors of early mortality. All 16 survivals followed up are in New York Heart Association class I or II. CONCLUSIONS: Anatomic and functional status of the patient, as well as procedural factors are related to Norwood operation early mortality. High mortality in hypoplastic left heart syndrome after stage I surgery indicates the necessity of assessing all factors which may determine further improvement in the outcome.     

Surgery for thoracic aortic aneurysms involving the distal arch through a left thoracotomy

Surgical outcome for thoracic aortic aneurysms involving the distal arch via a left thoracotomy using retrograde cerebral perfusion combined with profound hypothermic circulatory arrest was reviewed. Twelve patients with a atherosclerotic aortic aneurysm between 1994 and 1997 were involved. A proximal aortic anastomosis was made by means of an open aortic technique. For the first four patients, oxygenated arterial blood from cardiopulmonary bypass was perfused retrogradely through a venous cannula positioned into the right atrium. In the last eight cases, venous blood provided by a low-flow perfusion of the lower half body via the femoral artery, which was still oxygen-saturated, was circulated passively in the brain in a retrograde fashion with the descending aorta clamped. Prosthetic replacement was done between the distal arch and the proximal descending aorta in 6 patients and from the distal arch to the entire descending thoracic aorta in 6 patients. The median duration of hypothermic circulatory arrest and continuous retrograde cerebral perfusion was 36 minutes and 33 minutes respectively. The overall outcome was satisfactory without early mortality--all patients survived, although an octogenarian died of respiratory failure 1 year postoperatively. Another octogenarian with a ruptured aneurysm developed delay of meaningful consciousness, and other two patients with a severely atherosclerotic aneurysm suffered permanent neurological dysfunction (stroke) presumably due to an embolic episode. The safe and simple combination of profound hypothermic circulatory arrest, retrograde cerebral perfusion, and open aortic anastomosis protects the brain adequately and produces satisfactory results in surgery for aortic aneurysms involving the distal arch through a left thoracotomy.