Takahiro Tomoyasu

Regional high-flow cerebral perfusion improves both cerebral and somatic tissue oxygenation in aortic arch repair.

BACKGROUND Regional cerebral perfusion provides cerebral circulatory support during aortic arch reconstruction. We report the effectiveness of high-flow regional cerebral perfusion (HFRCP) from the right innominate artery to maintain sufficient cerebral and somatic oxygen delivery through collateral vessels. METHODS Frontal cerebral and thoracolumbar probes to measure somatic regional oxygen saturation (rSo(2)) were used to continuously measure oxygenation during cardiopulmonary bypass in 18 patients (weight, 2.1 to 4.3 kg) who underwent arch reconstruction using HFRCP (mean flow, 82; range, 43 to 108 ml/kg/min). Procedures included 9 Norwood procedures, 5 coarctation of aorta/interruption of aorta complex repairs, and 4 aortic arch repairs for a single ventricle. Mean HFRCP duration was 51 + or - 17 minutes under moderate hypothermia. Mean radial arterial pressure was kept at less than 50 mm Hg during HFRCP, and chlorpromazine (mean dose, 2.8 mg/kg) was given to all patients before and during HFRCP to increase regional cerebral perfusion flow. Plasma lactate concentration was measured before and after HFRCP. RESULTS During HFRCP, mean cerebral rSo(2) was 78.8% + or - 9.5%, somatic rSo(2) was 65.4% + or - 12.1%, and lactate concentration increased from 3.8 + or - 2.2 to 5.5 + or - 2.1 mmol/L. There was significant correlation between regional cerebral perfusion flow and somatic rSo(2). Significant inverse correlations were noted between regional cerebral perfusion flow and the increase of lactate concentration and between somatic rSo(2) and the increase of lactate concentration. CONCLUSIONS High-flow regional cerebral perfusion preserved sufficient cerebral and somatic tissue oxygenation during aortic arch repair. The reduction of vascular resistance of collateral vessels increased both cerebral and somatic blood flow, resulting in improved tissue oxygen delivery.

The bilateral pulmonary artery banding for hypoplastic left heart syndrome with a diminutive ascending aorta

A one-day-old neonate who was diagnosed with hypoplastic left heart syndrome (HLHS), aortic atresia, with a diminutive ascending aorta, and mitral atresia, was referred to us for cardiogenic shock because of excessive pulmonary blood flow. The patient underwent bilateral pulmonary artery banding (bPAB). After bPAB, the patients hemodynamics were still unstable because of coronary malperfusion, to proceed to undergo Norwood procedure at the age of 3 days. In this case, the stenosis of the ascending aorta, just proximal to the innominate artery caused coronary ischemia. The precise evaluation of the ascending aorta is necessary to perform the bPAB for HLHS with diminutive ascending aorta. If there is a sign of stenosis of the ascending aorta, the Norwood procedure should be performed as the first stage palliation, even for high-risk HLHS patients.

Miniaturized biocompatible cardiopulmonary bypass for the Fontan procedure.

PurposePostoperative inflammatory response and perioperative systemic edema are the risks of failed Fontan circulation. We evaluated the efficiency of the miniaturized, poly-2-methoxyethylacrylate (PMEA)-coated cardiopulmonary bypass (CPB) circuit, which we devised in 2003, in the Fontan circulation.MethodsThirty-seven patients who underwent the Fontan procedure between March 1996 and December 2006 were divided into two groups: one consisting of patients with a priming-volume >250 m on uncoated conventional bypass (group C; n = 20), and one consisting of those with miniaturized (<200 ml) and PMEA-coated circuits (group M; n = 17). We compared the body weight gain (%BWG), minimum platelet count, maximum postoperative C-reactive protein (CRP), and minimum hematocrit (Hct) levels during the operation, maximum white blood cell (WBC) count, and postoperative pleural effusion, between the two groups. Stepwise multiple logistic regression analyses were used to investigate the most affecting factors.ResultsThe %BWG and CRP levels were significantly lower in group M (P = 0.047 and P = 0.012, respectively). The minimum platelet count was significantly higher in group M (P = 0.012). There were no significant differences in postoperative pleural effusion, minimum Hct, or maximum WBC.ConclusionThe miniaturized biocompatible CPB system reduced perioperative inflammatory responses.

Higher cerebral oxygen saturation may provide higher urinary output during continuous regional cerebral perfusion

ObjectiveWe examined the hypothesis that higher cerebral oxygen saturation (rSO2) during RCP is correlated with urinary output.MethodsBetween December 2002 and August 2006, 12 patients aged 3 to 61 days and weighing 2.6 to 3.4 kg underwent aortic arch repair with RCP. Urinary output and rSO2 were analyzed retrospectively. Data were assigned to either of 2 groups according to their corresponding rSO2: Group A (rSO2 ≦ 75%) and Group B (rSO2 < 75%).ResultsSeven and 5 patients were assigned to Group A and Group B, respectively.Group A was characterized by mean radial arterial pressure (37.9 ± 9.6 vs 45.8 ± 7.8 mmHg; P = 0.14) and femoral arterial pressure (6.7 ± 6.1 vs 20.8 ± 14.6 mmHg; P = 0.09) compared to Group B. However, higher urinary output during CPB (1.03 ± 1.18 vs 0.10 ± 0.15 ml·kg-1·h-1; P = 0.03). Furthermore our results indicate that a higher dose of Chlorpromazine was used in Group A (2.9 ± 1.4 vs 1.7 ± 1.0 mg/kg; P = 0.03).ConclusionHigher cerebral oxygenation may provide higher urinary output due to higher renal blood flow through collateral circulation.