Hiroaki Kawata

Management of univentricular heart with systemic ventricular outflow obstruction by pulmonary artery banding and Damus-Kaye-Stansel operation

BACKGROUND Some patients with univentricular hearts who are candidates for Fontan operation may develop ventricular outflow tract obstruction after pulmonary artery banding (PAB) or Fontan. However, the indication for Damus-Kaye-Stansel (DKS) operation for these patients has not been clear. To clarify the indication, the changes in the diameter of ventricular outflow tract and the feasibility of DKS operation before or with Fontan were investigated. METHODS Among the patients with univentricular heart who underwent PAB, 21 patients had probable ventricular outflow obstruction with an aorta arising from the morphologic right ventricle. Diameter of ventricular outflow tract was measured before and after PAB, Glenn, and Fontan operations with or without DKS, and indexed by normal value (%VOT). RESULTS Six patients died after PAB. In the surviving 15 patients, %VOT decreased significantly from 103% (median, range 75%-153%) to 75% (range 52%-153%) after PAB. Four with very small %VOT (52% to 63%) after PAB needed DKS with bidirectional Glenn or central shunt operation, and 5 with moderately small %VOT (67% to 109%) after PAB needed DKS concomitantly with Fontan. A patient with %VOT of 117% before Fontan required DKS after Fontan. A patient with %VOT of 153% underwent Fontan without DKS and obstruction did not develop after Fontan. The remaining 4 patients were under consideration for Glenn or Fontan operation. CONCLUSIONS The diameter of the ventricular outflow tract decreased after PAB and Fontan operations. DKS operations might be indicated before Fontan if the indexed diameter of ventricular outflow tract after PAB was below 70% and concomitantly with Fontan if it was below 120%.

Morphologic Analysis of Common Atrioventricular Valves in Patients with Right Atrial Isomerism

Abstract. The objective of the study was to examine the relation between the morphology of the common atrioventricular valve and regurgitation of the valve in patients with right atrial isomerism. We examined seven consecutive patients with documented right atrial isomerism who subsequently underwent postmortem examination during a 10-year period. The degree of regurgitation and the diameters of the common valve were evaluated via cineangiography, and the site of regurgitation was evaluated by echocardiography. The morphology of the common atrioventricular valve was assessed further at autopsy. Cineangiography revealed valve diameters ranging from 14.8 to 27.8 mm (mean 20.9 mm). Valvar regurgitation was revealed within 2 months of birth in all patients. Regurgitation abruptly worsened in three patients after placement of a Blalock–Taussig shunt or a central shunt and postintubation. Autopsies revealed that the common atrioventricular valve consisted of four leaflets in five patients, and three leaflets in two. The anterior leaflets were large and protruding in all patients, and the lateral leaflets were thickened in six. All patients had a mass consisting of the left lateral leaflets and chordae with direct attachment of the chordae to the ventricular muscle (the right lateral leaflet was attached to the ventricular muscle and immobile in one patient). The lateral leaflets clung to the ventricular wall and exhibited poor movement in six patients. Leaflets with poor mobility corresponded to the regurgitant valvar site as assessed by echocardiography in six patients; and the regurgitation in three patients with acute deterioration occurred at the valvar side with poor mobility. It is concluded that the common atrioventricular valve in patients with right atrial isomerism has morphologic characteristics that may be associated with valvar regurgitation and malignant potential for abrupt deterioration after replacement of systemic–pulmonary shunting.

Pulmonary and systemic arteriovenous fistulas in patients with left isomerism

Hepatic venous blood has been thought to play some role as a vasoactive agent in the development of pulmonary arteriovenous fistulas in patients with congenital heart disease. During the last 15 years, we have observed pulmonary arteriovenous fistulas in 3, and systemic arteriovenous fistulas in 2, patients from our 16 cases of left isomerism. During the same period, neither pulmonary nor systemic arteriovenous fistulas were detected among 50 patients with right isomerism. Pulmonary arteriovenous fistulas had developed in the absence of surgery in 1 of the patients. Both pulmonary and systemic fistulas were detected in an another patient, in whom the hepatic venous blood bypassed the pulmonary circulation. The level of somatostatin, which is known to reduce splanchnic blood flow, was high in the systemic venous blood of this patient. Although the mechanism of development of the fistulas has yet to be clarified, we should be aware that not only pulmonary, but also systemic arteriovenous fistulas can be found in patients with left isomerism, even prior to any surgical intervention.

Contractility–Afterload Mismatch in Patients With Protein-Losing Enteropathy After the Fontan Operation

This study aimed to clarify the relationship between onset of protein-losing enteropathy (PLE) and Fontan circulation, with special reference to the development of contractility–afterload mismatch. The PLE group comprised 9 patients who experienced PLE after undergoing the Fontan operation, and the control group consisted of 32 patients had did not experienced PLE more than 10 years after the Fontan operation. The study compared the pre- and postoperative values of arterial elastance (Ea), end-systolic elastance (Ees), and contractility–afterload mismatch (Ea/Ees). Furthermore, the variations in the values were examined during the preoperative, postoperative, and midterm postoperative periods in seven PLE patients who underwent cardiac catheterization at the onset of PLE and during the pre- and postintervention periods in three PLE patients who underwent surgical intervention to improve the Fontan circulation after the onset of PLE. Comparison of the values obtained before and after Fontan operations showed that the Ea values increased significantly in the PLE group. However, the pre- and postoperative Ees values did not differ in the two groups. During the postoperative period, Ea/Ees increased significantly, and the Ea and Ea/Ees values increased continuously until the onset of PLE in the PLE group. In the patients who underwent surgical intervention to improve the Fontan circulation after the onset of PLE, the Ea/Ees decreased significantly, and the serum albumin levels improved after the intervention. Contractility–afterload mismatch, mainly caused by the increase in the afterload of the systemic ventricle, may have an important role in the development of PLE after the Fontan operation.

Repair of left ventricular diverticulum with ventricular bigeminy in an infant

Surgical repair of left ventricular diverticulum usually is not required in infancy even though it combines with other anomalies. In addition to prevention of rupture of the diverticulum and thrombus formation, treatment of combined ventricular tachycardia is thought to be an indication for resection of the diverticulum. We describe a successful repair performed by excising the isolated left ventricular diverticulum under cardiopulmonary bypass in a 9-day-old infant. The combined ventricular bigeminy has disappeared 9 months after the operation.

Optimal degree of pulmonary artery banding—Adequate circumference ratio to calculated size from normal pulmonary valve dimensions

These findings suggest that PA banding may be suitable in children with congenital heart disease and excessive pulmonary flow, and that best results are obtained when the band circumference is < 90% of the standard pulmonary valve-ring circumference, as calculated from an equation derived from normal pulmonary valve dimensions. This guideline applies equally well to small infants weighing < 3 kg and to larger patients.

Use of the Damus-Kaye-Stansel procedure prevents increased ventricular strain in Fontan candidates

OBJECTIVES In Fontan candidates, we have recently been aggressively performing the Damus-Kaye-Stansel procedure (DKS) to prevent increased afterload on the systemic ventricle. The present study investigated the efficacy of the DKS procedure in terms of the ventricular function following a Fontan operation. METHODS Patients undergoing a Fontan operation were divided into three groups: DKS performed at the time of the bidirectional Glenn or Fontan operation (DKS group, n = 25); DKS not performed at any stage due to mild pulmonary stenosis (PS) (PS group, n = 23) and DKS not performed due to pulmonary atresia (PA) or severe PS (PA group, n = 24). Ventricular function, afterload on the systemic ventricle and atrioventricular valve regurgitation were compared between groups. RESULTS Cardiac catheterization before a Glenn or Fontan operation and at 1-year following the Fontan revealed significantly decreased ventricular end-diastolic pressure in the DKS group. The ventricular ejection fraction was significantly deteriorated in the PS group. Effective arterial elastance, as an index of total ventricular afterload, was increased after a Fontan in all groups, with a substantial increase in the PS group. As an index of ventricular mechanical efficiency, ventriculoarterial coupling was significantly increased only in the PS group. Cardiac ultrasonography revealed atrioventricular valve regurgitation above grade 3 persisting in many patients from the PS group. Semilunar valve function after DKS operation did not progress to moderate or worse in any patients. CONCLUSIONS The proactive performance of the DKS procedure prevents increased ventricular afterload, avoiding deterioration of cardiac function and contributing to improved long-term results following a Fontan operation.

Surgical atrial septostomy without cardiopulmonary bypass

Surgical atrial septostomy using a special atriotomy knife without cardiopulmonary bypass in patients with obstruction of the left-sided atrioventricular valve and complex cardiac anomalies is described. This procedure is effective, safe, and economical for patients in the acute stage after intracardiac repair, and available for patients with a closed fossa ovalis.

Idiopathic arterial calcification in infancy with twin−twin transfusion syndrome

Idiopathic arterial calcification in infancy (IACI) is a syndrome of unknown etiology, characterized by calcification of large and medium-sized blood vessels and marked intimal fibrous tissue proliferation that is demonstrated pathologically. 1,2 The present report describes a case of idiopathic arterial calcification in infancy with twin–twin transfusion syndrome (TTTS). The patient died of severe bifurcation stenosis in bilateral pulmonary arteries.

Surgical management of congenital cardiac defects in neonates and young infants born with extremely low weight

Surgical treatment of cardiac defects in infants born with extremely low weight is sometimes required during the neonatal period. Optimal timing of these operations has yet to be clarified. With this in mind, we reviewed our experience of surgical treatment for 29 infants born with extremely low weight between 1994 and 2001. The main surgical procedures were ligation of a patent arterial duct in 26, a Brock procedure in 2, and ligation of an aorto-pulmonary window in 1 infant. The age at operation ranged from 5 to 57 days, with a median of 30 days, and weighed from 506 to 902 g, with a median of 710 g. There were no deaths. For the 2 infants undergoing the Brock procedure, the reduced systemic blood flow also necessitated closure of the arterial duct. For almost all the 26 infants with a patent arterial duct, indomethacin was given as the initial therapy, but the duct had not closed completely. Increased symptomatology just before the operation due to reduced systemic blood flow, such as decreased cerebral blood flow, decreased urine output, and intestinal ischemia, mandated the earlier surgical ligation (r = -0.576, p = 0.004). The youngest infant needed an infusion of catecholamines perioperatively to maintain stable hemodynamic conditions (r = 0.554, p = 0.003). In 4 infants, including the youngest 2, steroids were administered intravenously just after the ligation. Our results suggest that reduced systemic blood flow is the main indication of surgical repair in infants born with extremely low weight. Even for one in whom the supply of pulmonary blood is dependent on the arterial duct, early reconstruction of the pulmonary arterial pathways, using the Brock procedure, followed by ligation of the duct, is required. Acute adrenal insufficiency should not be overlooked just after the surgery, particularly in the youngest patients.