Yuichi Shiokawa

Selective cerebral perfusion technique during aortic arch repair in neonates

We describe selective cerebral perfusion techniques for repair of the aortic arch in neonates. These techniques may help protect the brain from ischemic injury caused by a cessation of cerebral perfusion for aortic arch reconstruction in patients with hypoplastic left heart syndrome or interrupted aortic arch.

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.

Total cavopulmonary connection with an extracardiac conduit: experience with 100 patients

BACKGROUND In the Fontan procedures total cavopulmonary connection with an extracardiac conduit is a concern. The potential benefits of an extracardiac conduit may be the avoidance of postoperative supraventricular arrhythmias over the long-term, hemodynamic benefits due to laminar flow, possibility of completion without anoxic arrest, and applicability to anomalous systemic or pulmonary venous return, or both anomalous systemic and pulmonary venous return. We demonstrate early to midterm results of total cavopulmonary connection with an extracardiac conduit. METHODS Between March 1994 and February 2000, a total of 100 patients underwent total cavopulmonary connection with an extracardiac conduit. In 27 patients, who underwent a single stage total cavopulmonary connection operation, 7 were done without palliation. Seventy-three patients had undergone a bidirectional Glenn shunt before completion of the total cavopulmonary connection. We used an expanded polytetrafluoroethylene tube graft as the extracardiac conduit. RESULTS Cardiopulmonary bypass time was 133.2+/-55.2 minutes. Myocardial ischemic time was 38.5+/-23.2 minutes in 40 patients who needed cardioplegic cardiac arrest for intracardiac procedures. Intraoperative fenestration was done in only 1 patient. There were no operative deaths. During follow-up of 37.3 months, there were 5 late deaths. When compared with the patients treated by the lateral tunnel technique in our institute, there was no significant difference in actuarial survival rate, but the event free rate of the extracardiac conduit group was significantly superior to the lateral tunnel group. CONCLUSIONS Total cavopulmonary connection with the extracardiac conduit produced good results in short to midterm follow-up.

Midterm surgical results of total cavopulmonary connection : clinical advantages of the extracardiac conduit method

OBJECTIVE We evaluated the midterm surgical outcomes of intra-atrial lateral tunnel and extracardiac conduit total cavopulmonary connection to clarify the clinical superiority. METHODS Patients (n = 167) underwent total cavopulmonary connection (88 with lateral tunnel and 79 with extracardiac conduit) from November 1991 to March 1999. Survival, incidence of reoperation and late complications, exercise tolerance, hemodynamic variables, and plasma concentration of natriuretic peptide type A were compared. In the lateral tunnel group, time-related change in lateral tunnel size was investigated for its relationship to postoperative arrhythmias. RESULTS The 8-year survival was 93.2% in the lateral tunnel group and 94.9% in the extracardiac conduit group. Seven reoperations were performed in the lateral tunnel group but none in the extracardiac conduit group. Supraventricular arrhythmias developed in 14 patients (15.9%) in the lateral tunnel group and in 4 patients (5.1%) in the extracardiac conduit group (P =.003). Freedom from cardiac-related events was 72.5% in the lateral tunnel group and 89.8% in the extracardiac conduit group at 8 years (P =.0098). Hemodynamic variables and exercise tolerance were similar in both groups but plasma natriuretic peptide type A concentration, a parameter of atrial wall tension, was higher in the lateral tunnel group. In the lateral tunnel group, intra-atrial tunnel size increased by 19.4% during the 44.2-month interval and the percent increase in tunnel size was an independent predictor of supraventricular arrhythmias. CONCLUSIONS The midterm survival, hemodynamic variables, and exercise tolerance were similar and satisfactory in both lateral tunnel and extracardiac conduit groups; however, the incidence of cardiac-related events was significantly less frequent in the extracardiac conduit group. In the lateral tunnel group, careful observation is required to monitor the relationship of the dilating tendency of the intra-atrial tunnel and the development of late complications.

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.

Mixed type of total anomalous pulmonary venous connection

BACKGROUND The mixed type of total anomalous pulmonary venous connection is a rare condition in which some diagnostic and surgical problems still remain to be solved. METHODS In 9 patients a single pulmonary vein was connected to the systemic vein at a site different from the drainage site of the confluence of three other pulmonary veins. In 2 other patients, four pulmonary veins made a confluence which had two drainage sites. Correct diagnosis was made in all 7 patients who received cardiac catheterization but only in 5 of the 9 patients by color Doppler echocardiography. Total correction was performed in 3 patients and the single anomalous pulmonary vein was left uncorrected in 8 other patients. RESULTS There were two in-hospital deaths. Seven patients with a single residual anomalous pulmonary vein have been in good condition without clinical symptoms of congestive heart failure or pulmonary hypertension. CONCLUSIONS Diagnosis of mixed type of total anomalous pulmonary venous correction by echocardiography is sometimes difficult. When a mixed type is suspected, cardiac catheterization is recommended if the condition of the patient permits it. A single anomalous pulmonary vein may be left uncorrected without serious complications, but close observation is needed to prevent congestive heart failure and pulmonary vascular obstructive disease.

Anomalous origin of the right pulmonary artery from the ascending aorta

Five cases of anomalous origin of the right pulmonary artery from the ascending aorta were seen at our hospital. Patients 1 and 2 had an intact right pulmonary artery originating from a right posterior aspect (proximal form), and primary anastomosis of the right pulmonary artery and main pulmonary trunk was performed. Patients 3 and 4 showed a narrowing right pulmonary artery originating from near the base of the innominate artery (distal form). The stenotic right pulmonary artery was reconstructed with an 8-mm graft in patient 3, whereas patient 4 became inoperable because complete obstruction had developed in the right pulmonary artery during the 3 months that the patient was waiting to undergo operation. In patient 5, primary anastomosis was undertaken, but morphologically the anomalous origin was of the distal form, so the occurrence of stenosis in the reconstructed right pulmonary artery was a matter of concern. The morphological type was found to be related to the surgical options in this anomaly. Therefore, primary anastomosis was considered the best choice for a correction of the proximal form, whereas a graft interposition with a resection of the stenotic portion on the right pulmonary artery was deemed preferable in the distal form.

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.

Revised Technique of Cardiopulmonary Bypass in One-Stage Repair of Interrupted Aortic Arch Complex

Twenty infants with interrupted aortic arch associated with various intracardiac anomalies underwent primary complete repair using pulsatile high-flow cardiopulmonary bypass with a short period of circulatory arrest. Age at repair ranged from 11 to 126 days (mean age, 43 days). Weight ranged from 2.2 to 5.5 kg (mean weight, 3.4 kg). Associated cardiac lesions included ventricular septal defect (14 patients), truncus arteriosus (3), transposition of the great arteries (2), and aortopulmonary window (1 patient). Left ventricular outflow tract obstruction was relieved in 2 patients. The aortic arch was reconstructed with a polytetrafluoroethylene graft in 7 patients and by direct anastomosis in the most recent 11 patients. An arterial cannulation method has been devised to facilitate direct anastomosis between the ascending aorta and the descending aorta, to lessen circulatory arrest time, and to prevent dangerous laceration and postoperative narrowing of the thin, small ascending aorta at the cannulation site. Two patients died, a surgical mortality rate of 10%. There has been one late death, which was due to severe truncal valve insufficiency. The other patients are doing well with a mean follow-up of 3 years 6 months. Restenosis of the direct anastomosis has not been noted in any patient. However, subaortic stenosis with pressure gradients of 30 to 40 mm Hg developed in 3 patients. In conclusion, one-stage repair including direct anastomosis for the aortic arch reconstruction and repair of all coexisting intracardiac defects is thought to be the treatment of choice.

The left ventricular outflow tract in atrioventricular septal defect revisited: Surgical considerations regarding preservation of aortic valve integrity in the perspective of anatomic observations

OBJECTIVE The anatomy of the left ventricular outflow tract in hearts with atrioventricular septal defect has been widely investigated, but controversies remain regarding detailed aspects of left ventricular outflow tract anatomy in the perspective of operative techniques to either prevent or relieve outflow tract obstruction. METHODS We investigated 29 postmortem hearts with an atrioventricular septal defect. Measurements were taken of the circumferences and of the widths of the components that make up the outflow tract, that is, the interventricular septum, the superior bridging leaflet, the left ventricular free wall, and the length of the tendinous cords. RESULTS The circumference of the left ventricular outflow tract immediately underneath the aortic valve was not different from that at the middle part of the outflow tract. Hearts with the partial type defect, characterized by separate atrioventricular orifices, had a smaller outflow tract than those with the complete variety. Although the anatomic constituents that contribute to left ventricular outflow tract obstruction are complex, this study showed that a reduced width of the interventricular septum was most intimately related to narrowing immediately underneath the aortic valve. Obstruction at the middle part of the left ventricular outflow tract was largely caused by reduced width of the interventricular septum together with short tendinous cords. CONCLUSIONS On the basis of these observations, we recommend detailed investigation of the anatomy of the left ventricular outflow tract immediately underneath the aortic valve, before surgical attempts to relieve outflow tract obstruction, because in some procedures the integrity of the aortic valve will be at stake.