Kouji Fukae

Clinical Results of the Staged Fontan Procedure in High-Risk Patients

BACKGROUND For high-risk Fontan candidates, the introduction of a bidirectional Glenn shunt before total cavopulmonary connection (a two-staged strategy) may extend the indications for the Fontan procedure. The clinical results of the two-staged and one-staged Fontan procedure were thus reviewed and compared. METHODS Between November 1991 and July 1996, the two-staged strategy was performed in 40 high-risk Fontan candidates with a mean interval of 17.2 months after introducing the bidirectional Glenn shunt (staged group). We considered a young age (<2 years), high mean pulmonary arterial pressure (> or =20 mm Hg), high pulmonary vascular resistance (> or =3 Wood units), small pulmonary artery (Nakata index <200 mm2/m2), atrioventricular valve incompetence (> or = moderate), distortion of pulmonary artery, anomalous pulmonary venous return, and poor ventricular function as risk factors for the successful completion of Fontan circulation. During the same period, 68 patients underwent the modified Fontan procedure in a one-step fashion (primary group). RESULTS In the staged group after the bidirectional Glenn shunt, the mean pulmonary arterial pressure and ventricular end-diastolic pressure were both found to have decreased significantly to the same level as those in the primary group, whereas the pulmonary artery demonstrated a significantly smaller size than that in the primary group. Operative morbidity was similar in both groups. Operative mortality was also similar and low in both groups (1.5% in the primary group and 0% in the staged group). CONCLUSIONS A bidirectional Glenn shunt was found to be a useful interim palliation in high-risk Fontan candidates. This two-staged strategy may extend the operative indications for the Fontan procedure.

Clinical results of mitral valve repair by reconstructing artificial chordae tendineae in children

OBJECTIVE There are an increasing number of reports concerning mitral valve repair by reconstructing the chordae tendineae with the use of expanded polytetrafluoroethylene sutures in adults. However, little information is available about application or results of this technique in children. METHODS Between January 1995 and December 1997, 16 children who had from moderate to severe mitral regurgitation mainly as the result of a prolapse of the anterior leaflet (age range, 5 months-12.8 years) underwent mitral valve repair by reconstruction of artificial chordae. Either unilateral or bilateral Kay-Reed annuloplasty was also performed to correct annular dilatation in all patients. RESULTS No operative death or morbidity was observed. Before discharge, immediate postoperative echocardiography showed less than trivial mitral regurgitation in all patients. The follow-up was complete in all cases by a clinical examination and serial echocardiograms, and the median follow-up period was 14.8 months (range, 1.3-26.4 months). There were no valve-related events during the entire follow-up period. The degree of mitral regurgitation, estimated by echocardiography performed at recent follow-up period, was none in 5 patients, trivial in 10 patients, and mild in 1 patient. The diastolic and systolic dimensions of the left ventricle decreased and were 95.0% and 96.2% of the normal values, respectively. CONCLUSIONS Although further investigations and long-term results are still called for, mitral valve repair by reconstruction of the artificial chordae was found to be safe and effective even in infants and children.

Clinical results of arterial switch operation for double-outlet right ventricle with subpulmonary VSD

OBJECTIVE An arterial switch operation is considered a good alternative for the repair of double-outlet right ventricle (DORV) with atrioventricular concordance connection and subpulmonary ventricular septal defect (VSD) when intraventricular rerouting is not feasible. The clinical results of an arterial switch operation with ventricular septal defect closure for this anomaly were studied. METHODS Between 1986 and 1997, 27 patients ranging from 10 days to 5 years of age (mean 0.4 years) underwent an arterial switch operation with ventricular septal defect closure for the correction of double outlet right ventricle with subpulmonary VSD. The 50% rule was used to define double-outlet right ventricle. Arch anomalies were associated in nine cases, and were corrected either previously or simultaneously. A subarterial muscle resection was performed in 14 without any subsequent stenosis of the ventricular outflow tract. The relationship of the great arteries was mostly anteroposterior in 15 and mostly side by side in 12. The left coronary artery (main trunk or circumflex artery) courses behind the pulmonary artery in 15/27 (six/15 in the anteroposterior relation and ten/12 in the side by side relation). The Lecompte maneuver was used to reconstruct the pulmonary artery in all but five cases with a side by side relationship of the great arteries. RESULTS There was one operative death (3.7%) and three late deaths. The actuarial survival rate was 83 +/- 8% at 9 years. Right ventricular outflow tract obstruction including peripheral pulmonary stenosis developed in seven cases operated on in the early era. The reoperation free rate was 46 +/- 20% at 9 years. CONCLUSION Although double-outlet right ventricle with subpulmonary VSD has complex features, including an aortic arch obstruction and coronary artery anomalies, an optimal definitive surgical repair using an arterial switch operation can be performed safely with a thorough understanding of this variable anomaly. The prevention of right ventricular outflow tract obstruction at the time of an arterial switch operation may thus help improve the rate of late morbidity.

Surgical results of double-orifice left atrioventricular valve associated with atrioventricular septal defects.

BACKGROUND Double-orifice left atrioventricular valve (LAVV) is a rare but surgically important anomaly, which is regarded as a risk factor for surgical correction of atrioventricular septal defects (AVSDs). METHODS Of 209 consecutive patients with AVSDs, double-orifice LAVV was identified in 19 patients (9.1%, including 7 infants). Preoperative LAVV function, surgical procedures and results, incidence of postoperative LAVV dysfunction and reoperations were reviewed and compared between patients with this valve malformation (group I, n = 19) and those without it (group II, n = 190). RESULTS There were no operative or late deaths in group I. Preoperative LAVV function was similar in both groups. The cleft was totally closed in 77.2% of group II and 47.1% of group I (p < 0.01). In partial AVSDs, freedom from postoperative LAVV insufficiency was 77.0% in group II versus 30.5% in group I at 5 years (p = 0.009) and freedom from reoperation was 89.9% in group II versus 58.3% in group I at 5 years (p = 0.012); however, there was no difference in complete AVSDs. None of the infants in group I underwent total cleft closure and 4 of them showed more than moderate LAVV insufficiency postoperatively. CONCLUSIONS Double-orifice LAVV is a significant predictor for postoperative LAVV incompetence and reoperation in partial AVSDs, but not in complete AVSDs. Surgical procedures for the cleft should be individualized with careful intraoperative evaluation of the structure and function of this abnormal valve, especially in partial AVSDs and infants.

Trans-ventricular septal defect approach for resection of accessory mitral valve tissue

Accessory mitral valve tissue is a rare cause of left ventricular outflow tract obstruction, which can be difficult to recognize. Surgical resection by the conventional transaortic approach with or without left atriotomy is extremely difficult in infants with a small aorta. When a ventricular septal defect is present, it may be the best way to approach the accessory mitral valve tissue, because the ventricular septal defect is located just in front of it. Five infants underwent resection of accessory mitral valve tissue together with repair of other intracardiac malformations. In 3 infants, resection of accessory mitral valve tissue was easily performed through the ventricular septal defect, which required enlargement in 2 patients.

Maldistribution of the cerebral blood flow in retrograde cerebral perfusion

Retrograde cerebral perfusion (RCP) through a superior vena caval (SVC) cannula has now become a useful alternative for brain protection during aortic arch operations. However, little is still known about its physiological effects, especially regarding the flow distribution in the brain. We studied the cerebral blood flow distribution under hypothermic conditions using mongrel dogs (n = 6, weighing 9.5 to 14 kg). We measured the cerebral tissue blood flow of the cortex with a laser Doppler flowmeter and cerebral tissue blood flow of the medulla using the hydrogen clearance method. The cerebral blood distribution at 28 degrees C with a whole body bypass flow of 100 ml/kg per min and aortic pressure of 88.3 +/- 20.4 mmHg was used as a control. Then the body temperature was decreased to 20 degrees C and the descending aorta was cross-clamped just distal to the origin of the left subclavian artery to establish antegrade cerebral perfusion (ACP). The perfusion flow was decreased to 54.8 +/- 12.4 ml/kg per min so as to make the aortic pressure similar to the control conditions. After measuring the cerebral blood flow distribution in ACP, the perfusion was then switched to RCP through the bilateral internal maxillary vein and the SVC pressure was kept at 40 mmHg. In RCP, the cerebral blood flow of the medulla was quite similar to that in ACP (12.4 ml/min per 100 g versus 15.2 ml/min per 100 g, NS). In contrast, the cerebral blood flow of the cortex significantly decreased to 16% of the flow in ACP (7.8 perfusion units versus 50 perfusion units, P < 0.01). Because of the maldistribution of the cerebral blood flow in RCP, careful attention should be paid to the clinical application of this method.

Successful management of junctional tachycardia by hypothermia after a fontan operation

We report herein the findings of a 2-year-old boy in whom junctional tachycardia developed 2 days after he underwent a modified Fontan operation and thereafter was successfully treated by hypothermia without paralyzing and artificially ventilating the patient. Chlorpromazine was useful in achieving moderate hypothermia by surface cooling without producing any unfavorable effects associated with topical cooling.