Ko Yoshizumi

Risk Factors for Mortality After the Norwood Procedure Using Right Ventricle to Pulmonary Artery Shunt

BACKGROUND The purpose of this study was to describe the experience with staged surgical reconstruction of the hypoplastic left heart syndrome (HLHS) with a right ventricle to pulmonary artery conduit and to identify the risk factors that influence late outcome. METHODS Between February 1998 and June 2007, 62 patients with HLHS underwent a Norwood procedure by using right ventricle to pulmonary artery conduit (median age, 9 days [range, 1 to 57]; median body weight 2.7 kg [range, 1.6 to 3.9 kg]). The subsequent 47 patients underwent a bidirectional Glenn procedure (stage 2). Thirty-two patients underwent a modified Fontan procedure (stage 3). Follow-up was complete (median, 32 months; range, 1 to 101). RESULTS Hospital mortality after the Norwood procedure was 8% (5 of 62 patients). Between stages, 9 patients died, 3 before stage 2 and 6 before stage 3. There was 1 late death after stage 3. Overall survival was 76% (47 of 62). The estimated 1-year and and 5-year survival rates were 80% and 73%, respectively. Using the any-mortality as the endpoint, prematurity (gestational age <37 weeks), body weight less than 2.5 kg at stage 1 operation, and tricuspid regurgitation 2+ or more were associated with mortality. Using Cox regression analysis, body weight less than 2.5 kg and tricuspid regurgitation 2+ or more were two independent factors associated with midterm survival. CONCLUSIONS From 9 years of experience, despite good early survival after Norwood stage 1 palliation, low body weight and tricuspid valve regurgitation were still associated with worse outcome. More efforts should be made to improve the late results for patients with hypoplastic left heart syndrome.

Intracoronary Autologous Cardiac Progenitor Cell Transfer in Patients With Hypoplastic Left Heart Syndrome The TICAP Prospective Phase 1 Controlled Trial

Rationale: Hypoplastic left heart syndrome (HLHS) remains a lethal congenital cardiac defect. Recent studies have suggested that intracoronary administration of autologous cardiosphere-derived cells (CDCs) may improve ventricular function. Objective: The aim of this study was to test whether intracoronary delivery of CDCs is feasible and safe in patients with hypoplastic left heart syndrome. Methods and Results: Between January 5, 2011, and January 16, 2012, 14 patients (1.8±1.5 years) were prospectively assigned to receive intracoronary infusion of autologous CDCs 33.4±8.1 days after staged procedures (n=7), followed by 7 controls with standard palliation alone. The primary end point was to assess the safety, and the secondary end point included the preliminary efficacy to verify the right ventricular ejection fraction improvements between baseline and 3 months. Manufacturing and intracoronary delivery of CDCs were feasible, and no serious adverse events were reported within the 18-month follow-up. Patients treated with CDCs showed right ventricular ejection fraction improvement from baseline to 3-month follow-up (46.9%±4.6% to 52.1%±2.4%; P=0.008). Compared with controls at 18 months, cardiac MRI analysis of CDC-treated patients showed a higher right ventricular ejection fraction (31.5%±6.8% versus 40.4%±7.6%; P=0.049), improved somatic growth (P=0.0005), reduced heart failure status (P=0.003), and lower incidence of coil occlusion for collaterals (P=0.007). Conclusions: Intracoronary infusion of autologous CDCs seems to be feasible and safe in children with hypoplastic left heart syndrome after staged surgery. Large phase 2 trials are warranted to examine the potential effects of cardiac function improvements and the long-term benefits of clinical outcomes. Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01273857.

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.

Midterm to Long-Term Outcome of Total Cavopulmonary Connection in High-Risk Adult Candidates

BACKGROUND Adult patients who do not fulfill the classical Fontan criteria now undergo total cavopulmonary connection (TCPC). However, limited information is available on the results for high-risk adult TCPC. METHODS Twenty-five consecutive adult patients (aged 16 years or more) who underwent TCPC were retrospectively reviewed. The mean age at operation was 27 +/- 9 years (range, 16 to 52). The following items were considered as the potential risk factors according to previous reports: (1) aged more than 30 years (7 of 25); (2) heterotaxy (9 of 25); (3) systemic ventricular ejection fraction less than 50% (6 of 25); (4) atrioventricular valve regurgitation moderate or greater (6 of 25); (5) pulmonary arterial index less than 200 (7 of 25); (6) mean pulmonary arterial pressure 15 mm Hg or greater (3 of 25); (7) pulmonary arterial resistance 2.0 wood units or greater (11 of 25); (8) arrhythmias (13 of 25); (9) protein-losing enteropathy (3 of 25); (10) New York Heart Association (NYHA) functional class III or greater (9 of 25); (11) previous Fontan procedure (10 of 25); (12) systemic ventricular outflow obstruction (1 of 25); and (13) end-diastolic pressure of the systemic ventricle 11 mm Hg or higher (4 of 25). RESULTS The mean follow-up period was 57 +/- 45 months (range, 0 to 154). All patients had at least 2 risk factors (range, 2 to 8). There was 1 early death and 2 late deaths. Comparing the late survivors and nonsurvivors, no statistical significance was identified in the above risk factors. However, the patients with 6 or more risk factors had a significantly higher mortality rate than patients with fewer than 6 risk risk factors (p < 0.01). Age (p = 0.08), NYHA class (p = 0.13), and protein-losing enteropathy (p = 0.08) may be risk factors for late death. CONCLUSIONS The majority of the adult TCPC candidates tolerated the TCPC procedure in the early postoperative period. However, the accumulation of risk factors influences late mortality.

Clinical outcome of the Fontan operation in patients with impaired ventricular function

OBJECTIVE Although a staged Fontan strategy allows for an excellent outcome in high-risk patients, an impaired ventricular function remains a significant factor of early/late mortality and morbidity. This study evaluated the clinical outcome of the Fontan operation in patients with impaired ventricular function. METHODS A retrospective review was performed on 217 patients who had undergone the Fontan operation between 1991 and 2007. RESULTS Twenty-nine (13%) of the 217 patients had an impaired ventricular function (ejection fraction (EF) <50%). The median age at the time of the operation was 3 (range: 1-31 years) years. There were five adult patients. The ventricular morphology was right in 20 patients (including five hypoplastic left heart syndrome (HLHS)) and others (left and two-ventricle) in nine patients. Heterotaxy syndrome was present in eight patients. Previous surgical interventions included bidirectional Glenn anastomoses in 24, modified Blalock-Taussig shunts in two and pulmonary artery banding in two. The preoperative EF was 43+/-6%. Significant (moderate or severe) atrioventricular valve regurgitation was noted in four patients. The percutaneous oxygen saturation (SpO(2)) was 82+/-5%. The pulmonary artery pressure and pulmonary artery index were 11+/-3 mmHg and 296+/-102 mm(2)m(-2), respectively. All 29 patients underwent the Fontan operation without any early mortality. There were two late mortalities and two re-operations. EF was maintained at 59+/-15% at a median follow-up of 7.5 (range: 1-19) years. The percent normal systemic ventricular end-diastolic volume decreased from 174+/-95% to 124+/-39% (p<0.05). The SpO(2) increased to 92+/-2%. The mean cardiothoracic ratio in chest X-ray and B-type natriuretic peptide were 51% (range: 35-68%) and 22 pgml(-1) (range: 9-382 pgml(-1)), respectively. Three patients developed congestive heart failure, seven had arrhythmia and two developed protein-losing enteropathy. The New York Heart Association (NYHA) class functional class is I in 21 patients, II in five and III in one. CONCLUSIONS Acceptable clinical outcomes were observed at an intermediate follow-up of the Fontan operation in patients with an impaired ventricular function.

Single center experience with a low volume priming cardiopulmonary bypass circuit for preventing blood transfusion in infants and small children.

This retrospective study analyzed the current practice of blood transfusion-free open-heart surgery in 536 children weighing 5–20 kg undergoing surgery between 2004 and 2007. A miniaturized cardiopulmonary bypass (CPB) circuit was used (priming volume; 300 ml for the flow rate <1,500 ml/min; 550 ml for the flow rate of 1500–2300 ml/min). Modified ultrafiltration was routinely performed. Criteria for blood transfusion during CPB included a hematocrit of <20% and/or mixed venous oxygen saturation of <65%. Transfusion during CPB was avoided in 264 (49.3%) of the 536 patients (5–10 kg group, 29.0%; 11–15 kg group, 67.4%; 16–20 kg group, 80.8%). There was no neurological complication related to hemodilution. Multiple logistic regression analysis revealed that body weight, preoperative hematocrit, priming volume of CPB circuit, CPB time, and lowest hematocrit during CPB predict requirement of blood transfusion (p < 0.01). Transfusion rate was lowest in the atrial septal defect group (5.6%) and highest in tetralogy of Fallot group (78.7%), being associated with complexity of diagnosis and procedure required. Blood transfusion-free open-heart surgery may be achieved in the half of the patients weighing 5–20 kg, and further miniaturization of CPB circuit and refinement of perfusion strategy might reduce transfusion rate in patients <10 kg and/or with complex congenital heart disease.

The potential of disproportionate growth of tricuspid valve after decompression of the right ventricle in patients with pulmonary atresia and intact ventricular septa

OBJECTIVE Tricuspid valve size is the major determinant of outcomes for patients with pulmonary atresia with intact ventricular septum. Lack of right ventricle-pulmonary artery continuity is associated with poor tricuspid valve growth (decrement in Z-value). However, most reports did not show evidence for disproportionate growth of the tricuspid valve after establishment of right ventricle-pulmonary artery continuity. METHODS We studied 40 patients with pulmonary atresia with intact ventricular septum who underwent initial right ventricular decompression for planned staged repair. The initial Z-value of the tricuspid valve diameter (Zt1) was obtained from the echocardiography-derived normal value. The late Z-value (Zt2) was measured before definitive repair or the last available Z-value, if definitive repair was not yet reached. The factors associated with the changes of Z-values (Zt2 - Zt1) were analyzed. RESULTS The mean initial tricuspid Z-value (Zt1) was -6.2 +/- 3.5. After treatment (Zt2), the mean Z-value was -6.0 +/- 3.4 (n = 34). Overall, the tricuspid Z-values did not change. Individually, the change in Z-value (Zt2 - Zt1) was larger than +2 in 11 (32%) patients and smaller than -2 in 6 (18%) patients. Increases in Z-value (Zt2 - Zt1) were significantly associated with right ventricular pressure/left ventricular pressure ratio measured after initial palliation (r = -0.54; P = .001) and the initial tricuspid valve Z-value (Zt1) (r = -0.40; P = .02). CONCLUSIONS Disproportional growth of the tricuspid valve can occur, especially in patients with small tricuspid valves and lower right ventricular pressures after decompression. The findings support the possibility of neonates with small tricuspid valves undergoing biventricular repair after right ventricular decompression surgery.

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.

Repair of Ebstein's anomaly in neonates and small infants: impact of right ventricular exclusion and its indications

OBJECTIVES In cases of severe Ebsteins anomaly, it is essential to determine whether biventricular repair (BVR) or single-ventricle palliation is feasible. Since 1999, in our institution, we have used the novel technique comprising tricuspid valve (TV) closure and right ventricular and right atrial (RV/RA) exclusion to reduce the deleterious effects of an enlarged RV in patients with severe Ebsteins anomaly. However, in cases with good RV function, primary BVR is performed. In the present study, we describe our surgical strategy in the treatment of severely symptomatic neonates with Ebsteins anomaly. METHODS From June 1999 to October 2011, 12 neonates with a severely symptomatic Ebsteins anomaly underwent surgical repair. The mean age at the first operation was 29 ± 25 (range, 5-92) days; and the mean body weight was 2.8 ± 0.5 (range, 2.0-4.1) kg. The associated anomalies included pulmonary atresia with an intact ventricular septum in 7, critical pulmonary stenosis in 1, ventricular septal defect in 3 and coarctation of the aorta in 1 patient. The mean cardio-thoracic ratio (CTR) was 80 ± 14% (range, 57-98%). Preoperatively, 9 patients had grade IV tricuspid regurgitation (TR), as detected by echocardiography, and 6 required ventilator support. RESULTS Five patients underwent primary BVR. Seven patients underwent staged palliation using a modified Blalock-Taussig shunt (BT shunt) with/without RV/RA exclusion. There was 1 case each of hospital death and late death. The median follow-up duration in the present study was 6.5 years. Among the 8 patients who underwent TV repair, postoperative TR was trivial or mild in 6 patients, moderate in 1 and absent in 1. After surgery, the mean CTR and serum B-type natriuretic peptide levels decreased to 59 ± 14% (range, 45-70%) and 46 ± 28 (range, 12-83) pg/dl, respectively. CONCLUSIONS Critically ill neonates with Ebsteins anomaly can be successfully treated using RV/RA exclusion combined with a modified BT shunt in cases where RV function is poor. However, in cases of good RV function, we recommend the use of primary BVR.