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.

Gene transfection of beta 2-adrenergic receptor into the normal rat heart enhances cardiac response to beta-adrenergic agonist.

BACKGROUND: Beta-adrenergic receptor system has a major role in cardiac contraction. If the receptor can be increased by gene transfection by means of intracoronary infusion of beta 2-adrenergic receptor to the hearts in which the receptor is down-regulated, this maneuver may improve the cardiac function and may be applied as one therapeutic approach during cardiopulmonary bypass or percutaneous cardiopulmonary support. METHODS AND RESULTS: The beta 2-adrenergic receptor complementary DNA was transfected in vivo to the normal rat heart by intracoronary infusion by means of a hemagglutinating virus of Japan liposome method, and the transfected heart was transplanted into the abdomen of another rat. Four days after transfection, the sarcolemma of the cardiomyocytes was well labeled by immunohistochemical labeling. Expression of beta-adrenergic receptor in the heart was approximately 4 times greater than that in control hearts (134 +/- 42 vs 33 +/- 4 fmol/mg protein) according to a ligand binding assay. The cardiac response of the transfected heart to isoproterenol was shown to be enhanced in a Langendorff perfusion system: after isoproterenol, developed pressure and maximal derivative of the left ventricle were greater than in the control heart (200 +/- 12 vs 174 +/- 6 mm Hg and 4110 +/- 130 vs 3491 +/- 255 mm Hg/sec), and the minimal derivative of the left ventricle was markedly smaller (-3040 +/- 267 vs -2528 +/- 131 mm Hg/sec). CONCLUSIONS: These results indicate that expression of beta 2-adrenergic receptor was approximately 4 times greater than in normal rat hearts by gene transfection using a hemagglutinating virus of Japan liposome method, and the transfected hearts demonstrated marked enhancements in cardiac response to beta-agonist, suggesting that transfer of this gene by intracoronary infusion has potential as a novel approach to enhance cardiac function.

Staged unifocalization and anatomic repair in a patient with right isomerism.

Anatomic biventricular repair was successfully achieved subsequent to bilateral unifocalizations of the pulmonary blood supply using heterologous pericardial rolls in a patient with isomeric right appendages and major aortopulmonary collateral arteries.

Renewal of the Fontan circulation with concomitant surgical intervention for atrial arrhythmia.

BACKGROUND: Atrial arrhythmia remains one of the major complications in the longer term after the Fontan procedure. METHODS: Conversion to total cavopulmonary connection was carried out concomitantly with surgical intervention for atrial arrhythmia in 4 patients undergoing the Fontan procedure by atriopulmonary connection and having continual atrial fibrillation or flutter in the longer term after the initial procedure. RESULTS: The surgical intervention restored sinus rhythm. Transient atrial fibrillation occasionally occurred after the reoperation in 1 patient in whom duration of preoperative arrhythmic period had been 6 years, and defibrillation was needed twice. In the other 3 patients, no episodes of paroxysmal arrhythmia have been noted. Subsequent to renewal of the Fontan circulation, cardiac index increased, with systemic venous pressure decreasing. All 4 patients are currently doing well with their functional status of New York Heart Association functional class I. CONCLUSIONS: Combination of conversion to total cavopulmonary connection and concomitant surgical intervention for atrial arrhythmia is effective, when used appropriately and in a timely manner in patients with atrial arrhythmia in the longer term after the initial Fontan procedure by atriopulmonary connection.

Extended unroofing procedure for creation of a new ostium for anomalous left coronary artery.

A modified procedure to create an alternative ostium for the left coronary artery was successfully carried out in a patient having anomalous origin of the left coronary artery from the right coronary sinus of the aorta. The proximal portion of the artery had an intramural course. The newly constructed orifice was widely patent and functioning well 44 months later, without episodes of myocardial ischemia or aortic regurgitation.

Open heart operation in a young child with spherocytosis.

Open heart operations on patients with hereditary spherocytosis have been reported rarely. Young children who have not yet undergone splenectomy have a high risk of intraoperative hemolysis because of the heart-lung machine and secondary renal failure. We report the case of a 15-month-old child with spherocytosis who underwent an open heart operation without serious complications as a result of careful and appropriate perioperative management.

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.

Redirection of hepatic venous drainage after total cavopulmonary shunt in left isomerism.

BACKGROUND: Conversion from total cavopulmonary shunt (TCPS) to the Fontan circulation can improve cyanosis in patients with potential risks of development of pulmonary arteriovenous fistula (PAVF). METHODS: Inclusion of the hepatic veins in the pulmonary circulation was employed using an intra-atrial tube graft in 5 patients with left isomerism previously undergoing TCPS. Prior to the conversion, abnormal communication was identified between the azygos vein and either the hepatic or the portal vein in all. PAVF was seen in 3. RESULTS: All patients survived the procedure. Postoperative catheterization showed 13 +/- 2 mm Hg of superior caval venous pressure, and 2.3 +/- 0.4 L/min/m2 of cardiac index. Pulmonary arteriovenous fistula progressed markedly in the right lung even after the conversion in 2 patients, in whom the hepatic veins had been exclusively diverted to the left lung. Arterial oxygen saturation became below 65%, with exercise capacity reduced, in these 2 patients. The other patients remain asymptomatic. CONCLUSIONS: Total cavopulmonary shunt can be efficiently converted to the Fontan circulation by appropriately redirecting hepatic venous drainage to perfuse both lungs in a balanced fashion.

Gene transfection of hepatocyte growth factor attenuates reperfusion injury in the heart.

BACKGROUND: Hepatocyte growth factor (HGF), a ligand for the c-Met receptor tyrosine kinase, plays a role as organotrophic factor for regeneration of various organs. HGF has an angiogenic activity and exhibits a potent antiapoptotic activity in several types of cells. Although HGF and the c-Met/HGF receptor are expressed in the heart, the role of HGF in the heart has remained unknown. METHODS: After we analyzed changes in expression of endogenous HGF and c-Met mRNA levels in the rat left ventricle after myocardial infarction, the human HGF gene in hemagglutinating virus of Japan (HVJ)-liposome was transfected into the normal whole rat heart. Three days after transfection, the heart was subjected to global warm ischemia and subsequent reperfusion, followed by assessment of its cardiac functions. RESULTS: Both HGF and c-Met/HGF receptor mRNAs were expressed in adult rat heart, and c-Met/HGF receptor mRNA was upregulated in response to myocardial infarction. HGF-transfected heart showed significant increase of human HGF protein level in the heart. Cardiac functions in terms of the left ventricular developed pressure, maximum dp/dt, and pressure rate product in hearts with HGF gene transfection were significantly superior to those in control hearts. In addition, leakage of creatine phosphokinase in the coronary artery effluent in hearts with HGF gene transfection was significantly lower than that in control hearts. CONCLUSIONS: These data indicated that both HGF and c-Met/HGF receptor mRNAs were upregulated in response to myocardial ischemic injury, and that HGF is likely to have a cytoprotective effect on cardiac tissue, presumably through the c-Met/HGF receptor.

Replacement of the tricuspid valve in children with congenital cardiac malformations.

BACKGROUND AND AIM OF THE STUDY: When replacing the regurgitant tricuspid valve in children, the decision to use either a bioprosthesis or a mechanical valve remains controversial. METHODS: The atrioventricular valve for the pulmonary circulation was replaced in 11 young patients aged between 8 months and 13 years. Complications of congenital cardiac malformation were present in seven patients, and Ebstein's anomaly in three; tricuspid valvular regurgitation was an isolated lesion in one patient. A bioprosthesis was implanted on seven occasions, and a bileaflet mechanical valve on eight, including re-replacement of the valve in four patients. RESULTS: One patient died two years after implantation due to respiratory problems. Tricuspid stenosis due to valve calcification occurred in four bioprostheses at between four and nine years after initial replacement (57%). In three of these cases the native valve leaflets had not been removed. Thrombosis occurred in one patient with a mechanical valve; rereplacement was successful. Anticoagulant-related hemorrhage occurred in another patient. Among patients receiving a mechanical valve, 83% of valves were dysfunction-free after five and ten years. CONCLUSION: When replacing an atrioventricular valve for the pulmonary circulation in children, we prefer to use a low-profile mechanical valve, especially when extensive repair of intracardiac malformation has been carried out, but ventricular function is good. In children with poor cardiac performance, a bioprosthesis is preferred, with total resection of the native valve leaflets.

Re-replacement of the atrioventricular valve for the systemic circulation in children.

BACKGROUND AND AIM OF THE STUDY: The study aim was to determine whether re-replacement of the systemic atrioventricular (AV) valve can be achieved efficiently in children. METHODS: The systemic AV valve was re-replaced in 10 children. Initial replacement was needed for regurgitation in nine cases and congenital mitral stenosis in one case at a mean age of 3.7 +/- 3.1 years (range: 0.7-10.2 years). The initial prosthesis chosen was a mechanical valve in all cases; prosthesis size ranged from 16 mm to 27 mm. Reoperation was indicated at a mean age of 9.7 +/- 3.6 years (range: 3.5-14.8 years) because of non-structural dysfunction in five cases, prosthetic valve endocarditis in two, thrombosed valve in two, and progressive obstruction of the left ventricular outflow tract in one case. Fibrous tissues were extensively resected to enlarge the valvular orifice. A translocation maneuver was employed in five cases. RESULTS: Re-replacement using a bileaflet mechanical valve was successful, with no operative or late deaths. Up-sizing was feasible in six cases with the initial valve < or = 25 mm, the alternative prosthesis being 2-8 mm (mean 4.5 mm) larger than the initial one. Consecutive echocardiography demonstrated improved peak flow velocity across the AV valve (from 2.3 +/- 0.6 to 1.6 +/- 0.3 m/s). Catheterization showed improved mean pulmonary arterial pressure (from 32 +/- 13 to 21 +/- 3 mmHg). No change was seen in cardiac index (3.4 +/- 0.6 and 3.5 +/- 0.6 l/min/m2) or systemic ventricular ejection fraction (55 +/- 14% and 49 +/- 23%). CONCLUSIONS: Re-replacement of the systemic AV valve can be achieved efficiently, even in children, with up-sizing feasible by appropriate surgical maneuvers.

Replacement of the morphologically tricuspid valve in children with discordant atrioventricular connections.

BACKGROUND AND AIM OF THE STUDY: Our clinical experience was reviewed to determine the efficacy of replacement of the atrioventricular (AV) valve for the systemic circulation in children with discordant AV connections undergoing functional biventricular repair. METHODS: Nine children underwent replacement of the morphologically tricuspid valve at the age of 10 months to 15 years. Ventriculoarterial connections were discordant in five children, and double outlet right ventricle with pulmonary stenosis or atresia in four. In all children the prosthesis chosen was a mechanical valve; valve sizes ranged from 19 mm to 31 mm. RESULTS: One patient died of ventricular failure immediately after surgery. Two patients underwent reoperation for re-replacement at eight and 68 months after the initial replacement because of non-structural dysfunction. Complete AV block occurred after intracardiac maneuvers in the non-survivor. Transient AV dissociation was noted in another patient. General conditions improved greatly after surgery in all survivors. In the morphologically right ventricle placed for the systemic circulation the end-diastolic volume fell from 327 +/- 182% (range: 109-621%) to 169 +/- 97% (range: 85-352%) of the anticipated normal value (p = 0.03), while pressure fell from 13 +/- 4 (range: 7-19) mmHg to 8 +/- 3 (range: 2-12) mmHg (p = 0.005). The ejection fraction was only marginally reduced (47 +/- 13% (range: 26-62%) preoperatively versus 34 +/- 11% (range: 20-54%) postoperatively; p = 0.13). CONCLUSIONS: In children with discordant atrioventricular connections and severe regurgitation across the morphologically tricuspid valve, the valve can be efficiently replaced for the systemic circulation.

Double inlet right ventricle versus other types of double or common inlet ventricle: its clinical characteristics with reference to the Fontan procedure.

OBJECTIVE: To determine the clinical features in patients with double inlet right ventricle (DIRV) and separate atrioventricular (AV) valves in terms of the Fontan procedure. METHODS: Surgical procedures were carried out in 31 patients with this rare malformation. Their clinical characteristics were compared with similar features in 45 patients with double inlet left ventricle (DILV), 93 with common inlet right ventricle (CIRV), and 20 with common inlet left ventricle (CILV). RESULTS: Pulmonary atresia with the right and the left pulmonary arteries being confluent was seen in 58% of patients with DIRV, and pulmonary atresia with non-confluent pulmonary arteries in 15% (P=0.0001). The incidence of these findings was significantly higher when compared with DILV (P=0.0001). Reflecting these morphologic features, constructions of systemic-to-pulmonary shunts and extensive plasty to the pulmonary arteries were more frequently needed in patients with DIRV than in the others (P=0.04, 0.0001). The AV valves have become moderately or severely regurgitant in three with DIRV (10%). The Fontan procedure has thus been employed in 21 with DIRV (64%), this incidence being significantly higher than that seen in the CIRV (37%) group (P=0.01). Survival rate of 95% at 10 years in this group was as excellent as that in the DILV group, and obviously better than that in either CIRV or CILV (P=0.002). CONCLUSIONS: Although multiple palliative procedures might be frequently needed to maintain pulmonary perfusion, the Fontan circulation can be justifiably established in patients with DIRV, and regurgitation across the AV valves was not very common.

Continuous systemic perfusion improves outcome in one stage repair of obstructed aortic arch and associated cardiac malformation.

OBJECTIVE: To determine whether continuous systemic perfusion is of effective use when establishing primary repair of the aortic obstruction and associated cardiac malformations. METHODS: Since 1991, 56 infants have undergone reconstruction of interrupted (in 28) or coarctated (in 28) aorta, concomitantly with closure of ventricular septal defects in 37, and repair of other malformations in the remaining 19. Of these, total circulatory arrest (30+/-11 min) was employed in 23. In another 21 patients, perfusion was maintained for the carotid arteries with the descending aorta cross-clamped (31+/-15 min). The bodily organs were perfused throughout the operative procedures by placing dual aortic cannulae in the remaining 12 patients. RESULTS: The postoperative courses were less eventful in the non-circulatory arrest group than other groups of patients undergoing total or partial circulatory arrest, although these groups were operated in different time periods, and consequently, a general progress might be one reason for improvements in the surgical outcomes. All patients undergoing no circulatory arrest survived the primary repair, could have the sternum primarily closed, and had no episodes of cerebral bleeding. Prolonged tracheal intubation was needed just in one patient of this group. The amount of urine output during cardiopulmonary bypass was significantly greater in the non-circulatory arrest group than in the others. The maximal concentrations of urinary beta-microglobulin, serous creatinine, creatine phosphokinase, and glutamic oxaloacetic transaminase were lower in this setting. CONCLUSIONS: Continuous systemic perfusion was considered less invasive when concomitantly repairing the obstructed aorta and intracardiac malformations.

Total cavopulmonary connection in children with body weight less than 10 kg.

OBJECTIVE: To evaluate the results after total cavopulmonary connection (TCPC) in small children, our clinical experience was retrospectively reviewed. METHODS: Of 164 patients undergoing TCPC, the body weight at operation was less than 10 kg (8.8+/-1.1 kg) in 54, including 21 with visceral heterotaxy. The superior caval vein (SVC) was anastomosed to the pulmonary arteries in a bidirectional fashion. To construct a channel draining the inferior caval vein (IVC), an extended polytetrafluoroethylene (ePTFE) tube was placed intraatrially (in 15 patients) or outside the heart (in 13), its diameter being 14 mm in two patients, 16 mm in 12, and 18 mm or greater in 14. A heterologous pericardial baffle was used for intraatrial rerouting in 12 patients. A pedicled autologous pericardial roll was tailored as an extracardiac conduit in 11 patients, and the pulmonary trunk was directly anastomosed to IVC orifice in three. RESULTS: Seven patients, including five with right isomerism, died in the intermediate term because of infection of the ePTFE tube in two, respiratory problems in three, atrioventricular valvar regurgitation in one, and pulmonary venous obstruction in one. Postoperative catheterization showed; SVC pressure, 11+/-2 mmHg without a pressure gradient between SVC and IVC; systemic ventricular end diastolic pressure, 5+/-2 mmHg; end diastolic volume, 122+/-54% of the anticipated normal value; ejection fraction, 0. 56+/-0.11; and cardiac index, 2.9+/-0.7 l/min per m(2). With the follow-up of 1-116 (35+/-31) months, the IVC channel has not become obstructive in all, except for one, in whom a pedicled pericardial roll was severely obstructed because of its tortuous extracardiac course crossing in front of the vertebrae. Postoperative growth was generally stable, although body weights and heights were smaller in the majority of patients when compared with the anticipated standards for Japanese children. CONCLUSION: TCPC can be justifiably established in small children. The use of autologous tissues seemed preferable for constructing the IVC channel unless anatomic orientation was unsuitable.

Result of surgical treatments in patients with coronary-arterial obstructive disease after Kawasaki disease.

OBJECTIVE: To determine the efficacy of coronary artery bypass grafting (CABG) in young patients with coronary-arterial obstructive disease subsequent to Kawasaki disease. METHODS: CABG was employed in 100 patients. Age at operation ranged from 1 to 23 years at a mean of 10+/-5 years. The number of bypass grafts placed was 1-5/patient (a mean of 1.7+/-0.8). The left internal-thoracic artery (ITA) was used as a graft in 99 patients; the right internal thoracic artery in 39, the gastroepiploic artery in nine and the saphenous vein in 21. RESULTS: All patients survived the procedures. In the follow-up of 6.7+/-4.5 years, two patients died, one because of a traffic accident and the other due to sudden death. Considerable myocardial ischemia recurred postoperatively in 15, because of either obstruction of the bypass grafts or progression of other coronary-arterial obstructions. Of these, symptoms spontaneously regressed without interventional procedures in four, reoperation was indicated in four and catheter intervention was efficiently carried out in the remaining seven. Another two patients had episodes of critical ventricular arrhythmia; one of them with severe left ventricular dysfunction subsequently underwent cardiac transplantation. The patency rates of the arterial grafts were 94, 82 and 78% at 1, 5 and 10 years, respectively, and this was higher than that of the venous grafts (82, 63 and 36%, respectively). Strenuous exercise is currently prohibited in 15 patients, while the remaining 83 patients are doing well with no obvious restriction in their daily lives. CONCLUSION: Collaborating with catheter interventions, CABG using the arterial grafts can provide attractive results in patients with obstructive coronary arteries associated with Kawasaki disease.

Establishment of total cavopulmonary connection without use of cardiopulmonary bypass.

OBJECTIVE: To minimize deleterious postoperative influences of cardiopulmonary bypass on the pulmonary circulation immediately after the Fontan type procedure, total cavopulmonary connection was achieved without use of cardiopulmonary bypass. METHODS: Since April 1996, 15 patients including five patients with visceral heterotaxy, in whom no intracardiac procedure was needed, have undergone this operative maneuver. Age at operation ranged from 1.2 to 44.6 years. Construction of a systemic to pulmonary shunt had been previously employed in seven patients, banding of the pulmonary trunk in two patients, and the Norwood procedure in one patient. The superior caval vein was initially anastomosed to the pulmonary arteries in bidirectional fashion under temporary bypass from the superior caval vein to the atrium. The channel for draining the inferior caval vein was subsequently constructed with the aid of temporary bypass from the inferior caval vein to the atrium, using a Goretex tube in ten patients, using a pedicled autologous pericardial roll in four patients, and directly anastomosing the pulmonary trunk to the orifice of the inferior caval vein in one patient. In patients with visceral heterotaxy and an independent hepatic venous drainage, redirection of the blood flow via the caval vein as well as the hepatic vein could be successfully achieved by placing dual temporary bypasses into these veins. RESULTS: Postoperative courses were excellent in all patients. Superior caval venous pressure was 11 +/- 2 mmHg at 12 h after the operation. No blood transfusion was needed in nine patients(60%). CONCLUSION: This alternative operative procedure is undoubtedly attractive when establishing the Fontan circulation in patients undergoing no intracardiac maneuvers.

Ventricular outflow tracts after Kawashima intraventricular rerouting for double outlet right ventricle with subpulmonary ventricular septal defect.

OBJECTIVE: To determine whether or not the ventricular outflow tracts can be efficiently constructed in patients with double outlet right ventricle with subpulmonary ventricular septal defect by the Kawashima intraventricular rerouting in which the morphologically right ventricular outlet is divided into two, one for the systemic and the other for the pulmonary circulations. METHODS: The intraventricular rerouting procedure was carried out in nine patients with this particular malformation. Age at repair ranged from 35 days to 3 years old. The distance between the attachments of the tricuspid and the pulmonary valves was 10 mm or greater in all except one patient in whom the measured value was 3 mm. Resecting subaortic musculature appropriately, a tailored patch, either oval-shaped (in seven) or heart-shaped (in two), was placed to construct an unobstructed channel for the left ventricular outflow tract with its diameter greater than that of the anticipated normal aortic orifice at the time of repair. For an unobstructed channel to the pulmonary arteries, enlargement of the right ventricular outflow tract was carried out using a patch in six. RESULTS: All patients survived the operative procedure. On postoperative catheterization, mean pulmonary arterial pressure was 15 +/- 8 mmHg, and cardiac index was calculated as 3.3 +/- 0.6 l/min per m2. It proved that the constructed left ventricular outflow tract can become larger in the longer term. Pressure gradient across the left ventricular outflow tract was greater than 20 mmHg in two patients in the intermediate term. One of these two underwent reoperation for the obstruction 10 years after the initial repair. It was suspected that use of a heart-shaped internal conduit, which seems to result from inadequate conal resection, was one of the possible causes of such obstruction in the longer term. Pressure gradient of 47 mmHg was seen across the right ventricular outflow tract in one patient, although this patient has undergone no reoperation. Enlargement of the right ventricular outflow tract could minimize postoperative obstruction for the pulmonary pathway. CONCLUSIONS: The intraventricular rerouting remains one of the attractive surgical options for repair in this particular setting, in terms of successful construction of the ventricular outflow tracts.

Use of expanded polytetrafluoroethylene sutures as artificial tendinous cords in children with congenital mitral regurgitation.

OBJECTIVE: To determine the efficacy in the intermediate term of artificial cords inserted in children with congenital mitral regurgitation. METHODS: We reconstructed the tendinous cords using expanded polytetrafluoroethylene (ePTFE) sutures in 11 children with severe mitral regurgitation. In these patients, the aortic (anterior) leaflet of the mitral valve had been markedly prolapsed, the tendinous cords being partially lacking in seven, and elongated in the remaining four. In addition, one of the papillary muscles was hypoplastic in five and absent in three. The number of artificial cords constructed varied from two to six. Conventional annuloplasty was performed in all to plicate the dilated annular attachment of the valve. Ventricular septal defect was present in four patients, and other associated malformations in another two. Age at operation ranged from 9 months to 9 years old, with a mean of 4.5 years. RESULTS: All patients survived the operation. No reoperation has been needed thus far. No complications were encountered related to the use of the prosthetic materials or anticoagulation. As judged by echocardiography, regurgitation became trivial or slight immediately after the repair. In two patients, however, regurgitation recurred within 1 year of the operation. Coaptation between the leaflets was maintained by a compensatory growth at the site of attachment of the artificial cords. Catheterization demonstrated significant improvements in the end-diastolic volume of the left ventricle. CONCLUSION: Expanded polytetrafluoroethylene sutures can be used as artificial cords when attempting to repair the malformed mitral valve in children, providing excellent results in the short- and the intermediate-term after the surgical procedure.

Congenital diverticulum of the left ventricle.

We present a case of a congenital left ventricular diverticulum of fibrous type that was surgically repaired. Considering the potential risks such as rupture, systemic thromboembolism, and arrhythmia, an early surgical intervention should be employed for this rare abnormality even in a child without clinical symptoms.