Hidetaka Oku

Expanded Polytetrafluoroethylene Monocuspid Valve for Right Ventricular Outflow Tract Reconstruction

BACKGROUND Numerous materials have been used for reconstruction of the right ventricular outflow tract (RVOT) in patients with complex congenital heart defects. METHODS Between January 1982 and March 1999, 19 patients (10 boys and 9 girls; mean age, 8.5 years) with severe RVOT obstruction underwent reconstruction using a transannular patch and expanded polytetrafluoroethylene (ePTFE) monocuspid valve. RESULTS There were no perioperative deaths. Postoperatively, the mean +/- standard deviation RVOT gradient was 12 +/- 9 mm Hg. Echocardiography showed good motion of all cusps, and most had no or trivial pulmonary regurgitation. The difference between the preoperative and postoperative mean ratio of right-to-left ventricular peak systolic pressure was significant (p = 0.0001). In the 8 patients followed for 3 years or longer, pulmonary regurgitation was mild or better in 5 and moderate in 2, and the mean peak systolic RVOT gradient was 16.3 +/- 5.9 mm Hg. Five patients had good mobility of the monocusps. Two patients needed reoperation because of stenosis at the distal anastomosis of the transannular patch; 1 patient died. CONCLUSIONS The ePTFE monocuspid valve may be useful in reconstruction of the RVOT.

Right ventricular outflow tract prosthesis in total correction of tetralogy of Fallot.

Right ventricular outflow tract obstruction was relieved by placing outflow patches across the pulmonary annulus in 39 of 195 patients who underwent total correction of tetralogy of Fallot. The mortality rate in these 39 patients was 12.8%, which did not differ significantly from the overall mortality of 11.3% (p = 1.00). The ratio of the pulse pressure to pulmonary artery systolic pressure as an index of pulmonary insufficiency was dependent on the cross-sectional area index (CSAI) of the pulmonary annulus after enlargement, as shown in the regression equation Y = I - 0.63/(X - 0.07) (r = 0.79, p <0.05). When the CSAI was 2.5 cm2/m2 or less and a single cusp was mounted on the outflow patch, the pulmonary insufficiency was negligible and the right ventricular end-diastolic pressure was 10 mm Hg or less. In patients without outflow patches, the right ventricular-to-pulmonary arterial systolic pressure gradient and the right ventricular-toaortic systolic pressure ratio 1 month after surgery was dependent on the CSAI, as shown in the regression equations Y = 54.0/X2 + 5.6 (r = 0.76, p < 0.01) and Y = 0.42/X2 + 0.36 (r = 0.72, p < 0.01), respectively. These two equations may also be applied in the case of patients with outflow patches with a single cusp. Thus, when the outflow patch is used, the CSAI must be larger than 1.75 cm2/m2 and less than 2.5 cm2/m2, and a single cusp should be mounted on the outflow patch.

Postoperative Size of the Right Ventricular Outflow Tract and Optimal Age in Complete Repair of Tetralogy of Fallot

Abstract One hundred forty-three patients underwent complete repair of tetralogy of Fallot with an overall mortality of 14.7%. The mortality rate correlated with the preoperative pulmonary artery to aorta (PA/Ao) diameter ratio but not with age. A retrospective study revealed that for success, the postoperative pulmonary annulus should be over 1.75 cm 2 per square meter of body surface area (BSA) in patients with a BSA of less than 0.6 m 2 at operation. The younger the patient, the lower was the ratio of right ventricular to aortic systolic pressure, even when the cross-sectional area index (CSAI) of the pulmonary annulus was the same. Even with application of an outflow patch, pulmonary regurgitation was negligible when the CSAI was less than 2.6 cm 2 /m 2 . The pulmonary vascular response to increased blood flow was excellent in younger patients. Residual ventricular septal defect and recurrent pulmonary stenosis were unrelated to age. Thus, for symptomatic patients, even infants, we recommend that complete repair be attempted when the PA/Ao diameter ratio is over 0.3. For patients in whom this ratio is less than 0.3, operation should be undertaken when the average diameter index of the arterial pathway to the right upper lobe is above 4 mm/m 2 . Should this index be less than 4 mm/m 2 , a two-stage operation is recommended.

Modified Ultrafiltration May Improve Postoperative Pulmonary Function in Children with a Ventricular Septal Defect

Abstract To evaluate the effectiveness of modified ultrafiltration (MUF) on ventricular septal defect (VSD) repair in children, we retrospectively examined 10 patients who underwent VSD repair with MUF at the Kinki University School of Medicine hospital between June 1998, and December 1998 (MUF group). These patients were compared with 14 patients who underwent the same procedure without MUF (control group) between January 1997 and June 1998. Systolic blood pressure and hematocrit values increased significantly during MUF. By the time of postoperative transfer to the intensive care unit, PaO2 was higher in the MUF group than in the control group (503.3 ± 112.2 mmHg vs 376.3 ± 149.2 mmHg; P = 0.0491), whereas A-aDO2 was lower in the MUF group than in the control group (171.9 ± 109.2 mmHg vs 301.1 × 150.4 mmHg; P = 0.0449). These findings demonstrate that MUF had a beneficial effect on pulmonary function in children who underwent surgery to repair a VSD.

Bivalvation with bridging for common atrioventricular valve regurgitation in right isomerism

A child with regurgitation in the common atrioventricular valve associated with complex heart disease underwent bivalvation with bridging for common atrioventricular valve regurgitation and arterial-pulmonary shunt for low pulmonary blood flow. Postoperative cardiac catheterization and color Doppler echocardiography revealed elimination of atrioventricular valve regurgitation and ventricular enlargement, reflecting an increase in pulmonary artery blood flow. We describe the concept and technique of bivalvation with bridging for common atrioventricular valve regurgitation.

Semilunar Valve Replacement with a Cylindrical Valve

Abstract A cylindrical valve was designed to prevent regurgitation of the semilunar valve. The valve is made of a sheet of polytetrafluoroethylene (PTFE) or porcine pericardium, and has three cusps and three commissures. The diameter of the valve is equal to the height of the cusps. We have used these valves in pulmonary stenosis after Jatenes operation and total correction of tetralogy of Fallot, and for truncal valve regurgitation. Regurgitation was trivial on color Doppler echocardiography in all cases. Advantages in comparison with the implantation of commercially available artificial valves include the ability to insert a larger size and no compression of the valve ring when closing the sternum. Outflow tract obstruction does not occur even when the valve is implanted in a small infant. In the present report, we describe this simple technique.

Percutaneous cardiopulmonary support for the treatment of right ventricular thrombus

The management of patients with acute pulmonary embolism (PE) remains controversial, despite an improved understanding of its pathogenesis and diagnosis. Haemodynamic instability due to right ventricular failure and hypoxia following PE is associated with a high mortality rate. This report describes a case of a 22-year-old woman with leukaemia in which percutaneous cardiopulmonary support (PCPS) was used as an adjunct to thrombolytic therapy in the treatment of right ventricular thrombus with acute PE. The patient has since undergone regular follow-up on an outpatient basis without showing any recurrence of thromboembolism at 2 years postoperatively. This experience suggests that supportive PCPS may provide favourable clinical outcomes in high-risk patients with severe PE.

Total cavopulmonary connection using a pedicled pericardial conduit for a patient with apicocaval juxtaposition

A 5-year-old boy, with a double inlet solitary ventricle, pulmonary atresia, and apicocaval juxtaposition underwent an extracardiac total cavopulmonary connection. A pedicled pericardial conduit was placed behind the ventricle to make a straight pathway between the inferior vena cava and pulmonary artery. This report presents a solution for managing patients with complicated heart defects with apicocaval juxtaposition during the completion of a total cavopulmonary connection.

Beneficial effects of ω-3 fatty acid treatment on the recovery of cardiac function after cold storage of Hyperlipidemic rats

Cardiac effects of omega-3 polyunsaturated fatty acids (PUFAs) were studied in female Wister rats fed a standard diet (control [C] diet) or a high-cholesterol (HC) diet. Subgroups of rats from these groups were treated with eicosapentaenoic acid-E (EPA) or docosahexaenoic acid-95E (DHA) for 5 weeks. Although plasma total cholesterol (TC) and triglyceride (TG) levels were higher in each group fed the HC diet versus each group fed the C diet, EPA administration with the HC diet (HC + EPA) significantly (P < .05) reduced these levels. An isolated working-heart preparation was used to determine cardiac function. Cardiac output (CO) was lower in rats fed the HC diet and HC + DHA versus any of the groups fed the C diet (P < .05). In addition, left ventricular (LV) maximum differentiation of pressure-time curve (dp/dt) was lower in the rats fed the HC diet versus any of the C diet groups (P < .05). After evaluation of cardiac function in each rat, the heart was stored in a histidine-tryptophan-ketoglutarate solution for 8 hours at 4 degrees C. The heart was then reperfused, and recovery of cardiac function was evaluated. No significant differences were observed for post-preservative cardiac function within the C diet groups. However, within the HC diet groups, HC + EPA significantly (P < .05) improved the recovery of cardiac function. In addition, HC + DHA also significantly (P < .05) improved the recovery of coronary flow (CF) and LV dp/dt. No significant differences were observed for plasma TC and TG concentrations in the C diet groups. EPA administration significantly decreased cardiac levels of palmitic, oleic, and linoleic acids in the HC diet groups. No significant differences were observed for cardiac levels of free fatty acids (FFAs) within the C diet groups. Cardiac EPA and DHA levels were significantly (P < .05) elevated in EPA- or DHA-treated rats compared with the other diet-fed rats. Cardiac EPA levels were also elevated in DHA-treated rats compared with untreated rats (P < .05). These results suggest that EPA attenuates coronary and myocardial preservation injuries through an increase in serum lipids and an accumulation of myocardial FFAs resulting from a HC diet.

Reconstruction of Right Ventricular Outflow Tract by Pedicled Pericardial Valved Conduit

A modification of the Rastelli technique using a pedicled autologous pericardial valved conduit was performed on 3 patients aged 10 months to 3 years. Two patients in whom a prosthetic gusset was not used or was partially used showed good recovery during the follow-up period (3 months to 3 years). The pedicled autologous pericardial conduit may be expected to increase its diameter with physical growth.