Myocardial protection in coronary occlusion by retrograde cardioplegic perfusion via the coronary sinus in dogs. Preservation of high-energy phosphates and regional function.

The lack of adequate myocardial preservation because of maldistribution of cardioplegic solution in coronary artery disease remains a perplexing problem. We compared two methods of cardioplegic delivery in dogs: antegrade aortic root perfusion (Group I) and retrograde coronary sinus perfusion (Group II). Metabolic changes and regional function in the coronary occlusion model, in which the left anterior descending artery was occluded at its prediagonal portion, were studied. In the distribution of the occluded coronary artery, adenosine triphosphate and total adenine nucleotides at the end of 120 minutes of ischemia were preserved better in Group II (16.80 and 22.94 mumol/gm dry weight) than in Group I (11.06 and 16.19 mumol/gm dry weight, p less than 0.05). Lactate accumulation tended to be higher in Group I than in Group II (114.0 and 87.2 mumol/gm dry weight, respectively; not significant). Percent recovery of segmental shortening was also better in Group II than in Group I (100% and 22.3% at the same left atrial pressure, 4 mm Hg; p less than 0.01). In the region supplied by the intact coronary artery, there were no significant differences between the two groups with regard to metabolic changes and regional function. These observations suggest that retrograde cardioplegic perfusion via the coronary sinus is preferable for surgically treatment of severe coronary artery disease.

Pulmonary vascular disease and operative indications in complete atrioventricular canal defect in early infancy.

Pulmonary vascular disease was morphometrically analyzed in 67 patients (mean age, 19 months) with isolated complete atrioventricular canal defect. Complete obstruction of the small pulmonary arterial lumen resulting from acute fibrous proliferation and atrophy of the peripheral arterial media, which were considered absolute operative contraindications, were characteristic in six patients with Down's syndrome. Morphometric analysis of medial thickness revealed that thinning of the media of the small pulmonary arteries is generally observed at around 6 months of age in patients with complete atrioventricular canal defect and that the media in patients who have complete atrioventricular canal defect and Down's syndrome was thinner than that in such patients without Down's syndrome. These results suggest that thinning of the media as a result of two factors--Down's syndrome and aging--facilitates the rapid occurrence of fibrous intimal proliferation. Therefore intracardiac repair is desirable within 6 months of life, before medial thinning, in patients with complete atrioventricular canal defect and Down's syndrome. Excluding patients with absolute operative contraindications, the scores of the index of pulmonary vascular disease in operative survivors were below 2.0 and death occurred when scores were more than 2.2. The pulmonary vascular resistances measured in room air and by the oxygen inhalation and tolazoline tests in patients with operative contraindications were more than 7.3, 3.8, and 6.6 units.m2, respectively. We thus conclude that lung biopsy should be undertaken for patients in whom pulmonary vascular resistance is beyond these values to determine the appropriateness of surgical intervention.

Arterial switch operation for transposition of the great arteries, with special reference to left ventricular function.

Between June 1984 and September 1987, 48 patients underwent Lecompte's modification of the arterial switch operation for transposition of the great arteries, including transposition with intact ventricular septum with preparatory pulmonary artery banding (n = 18), with patent ductus arteriosus (n = 11), with dynamic left ventricular outflow tract obstruction (n = 4), and transposition with ventricular septal defect (n = 15). Ages ranged from 12 days to 36 months (mean 8 months) and weights ranged from 2.7 to 12.8 kg (mean 5.7 kg). Two deaths occurred, yielding an operative mortality rate of 4.2%. Preparatory pulmonary artery banding resulted in an increase to 65 +/- 5 mm Hg in the left ventricular afterload. Linear regression of the optimum circumference of the band (Y, millimeters) against left ventricular end-diastolic volume (X, milliliters) yielded the following formula: Y = 0.23X + 19.7 (r = 0.885, p less than 0.001). Influence of left ventricular mass on cardiac function after anatomic correction was evaluated. The total amount of dopamine used after repair in patients in whom the left ventricular mass was less than 60% of normal was significantly larger than that in patients with a left ventricular mass greater than or equal to 60% of normal (p less than 0.002). The left ventricular end-diastolic volume in patients with a left ventricular mass less than 60% of normal increased significantly 2 months after operation (p less than 0.05), whereas it decreased in patients with a left ventricular mass greater than 60% of normal (p less than 0.01). We believe it is safe to perform this procedure in patients in whom the left ventricular mass is larger than 60% of normal. Most newborn infants with simple transposition can undergo correction between 10 and 20 days of life if the ductus arteriosus is kept patent with prostaglandin E1 and the left ventricle is thereby loaded. Preparatory pulmonary artery banding, when necessary, will be satisfactory if the left ventricular pressure is greater than 65 mm Hg and/or the left ventricular/right ventricular pressure ratio is greater than 0.8.

Primary repair of interrupted aortic arch and severe aortic stenosis in neonates.

Two infants, aged 36 days old (Case 1) and 18 days old (Case 2) with interrupted aortic arch types B and A, respectively, and with severe aortic stenosis, were successfully operated on by use of pulsatile cardiopulmonary bypass. The great arteries were normally related in Case 1 and were transposed in Case 2. Repair involved the following procedure: ligation of the patent ductus arteriosus, restoration of aortic continuity with an 8 mm polytetrafluoroethylene graft, placement of an internal patch to tunnel all left ventricular blood from the left ventricle through the ventricular septal defect into the pulmonary artery in Case 1 and patch closure of the ventricular septal defect in Case 2, transection of the main pulmonary artery, anastomosis between the proximal pulmonary artery and the ascending aorta, and interposition of a valved conduit between the right ventricle and the distal pulmonary artery. The operative field could be approached easily through a median sternotomy. Postoperative cardiac catheterization revealed satisfactory anatomical and hemodynamic results in both cases.

Myocardial distribution of retrograde flow through the coronary sinus of the excised normal canine heart.

Myocardial distribution of the retrograde flow through the coronary sinus in the canine heart was evaluated by observing the corrosion casts of the myocardial vessels after coronary sinus injection of a low-viscosity resin, Mercox, a compound that passes through capillaries. The apex and the left ventricular free wall were well perfused at the microvascular level, even in the presence of complete left main coronary artery occlusion, whereas the right ventricular free wall was not perfused effectively at this level in any heart. Although there was considerable variation in the perfusion of the ventricular septum from heart to heart, the entire septum was not perfused in some of the hearts. We considered this poor perfusion of the septum to be due to the presence of well-developed thebesian veins in the septum. Retrograde coronary sinus perfusion of cardioplegic solution may be a valuable alternative to protect the left ventricular free wall, especially in cases of critical coronary artery stenosis or occlusion. However, antegrade perfusion should be used also, whenever possible, for adequate protection of the septum and the right ventricular free wall.

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.

Myocardial protection by retrograde cardioplegia in arterial switch operation.

Retrograde coronary sinus perfusion of cold cardioplegic solution was evaluated in infants undergoing an arterial switch operation for transposition of the great arteries. To assess myocardial injury during ischemia, hemodynamic measurements were conducted at weaning from cardiopulmonary bypass and a postoperative assay of creatine kinase isoenzyme MB was performed. In 22 infants with retrograde coronary sinus perfusion, the initial cardioplegic infusion was performed through the aortic root and additional infusion was repeated every 30 minutes by retrograde coronary sinus perfusion. The other 11 infants received additional solution by antegrade selective coronary artery perfusion. The aortic cross-clamp time in the retrograde coronary sinus perfusion group was significantly shorter than that in the antegrade selective coronary perfusion group (128 +/- 19 versus 143 +/- 21 minutes, p less than 0.05). There were no significant differences between the two groups in terms of postoperative hemodynamic variables and enzyme indexes. Eight neonates in the retrograde coronary sinus perfusion group also exhibited enzymatic and hemodynamic indexes similar to those of older infants. These results suggested that retroperfusion of cardioplegic solution was a safe and useful means of myocardial protection in infants and neonates because of the simplification of the operative procedure and the avoidance of traumatic injury to the coronary ostia.

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.

Open-heart surgery in infants using pulsatile high-flow cardiopulmonary bypass.

Pulsatile high-flow cardiopulmonary bypass (2.5 l/m2/min with a rectal temperature of 28 degrees C) combined with the Pulsatile Bypass Pump (Kontron Instrument) has been used at Fukuoka Children's Hospital in 259 cases of open-heart surgery in patients less than 1 year of age for a period of 5 years beginning July 1982. The overall results were satisfactory with a surgical mortality of 6.2% (VSD: 96 cases/2 deaths, TGA: 48/1, TAPVD: 34/3, Complete ECD: 15/1, IAA: 10/1, DORV: 10/1, HLHS: 7/4, TOF: 6/0, Truncus Art: 5/0, Others 28/3). The mean duration of cardiopulmonary bypass was 123 +/- 50 minutes during which time the patients had a positive water balance of only 28 +/- 38 ml per kg of body weight. The lowest positive water balance was noted in the patient group with 60-75 mmHg in peak systolic pressure and 30-45 mmHg pulse pressure divided by the pulsatile wave form. This value was significantly lower than other groups of patients with lower or higher peak systolic and pulse pressures. Urinary output during the first 24 hours after operation was 4.1 +/- 1.3 ml/kg/hour. Weight gain on the first postoperative day was 10 +/- 43 g per kg of body weight, and the duration of postoperative respiratory support was 4 +/- 5 days. In conclusion, pulsatile high-flow cardiopulmonary bypass is useful in infant open-heart surgery in light of operative techniques, water balance and postoperative recovery.

Primary repair for complete atrioventricular canal: recommendation for early primary repair.

Forty patients with complete atrioventricular canal (CAVC) underwent primary repair at Fukuoka Children's Hospital in Fukuoka, Japan, between August 1, 1981 and July 31, 1989. The age at repair ranged from 2 months to 6 years (mean 19 months); weight ranged from 2.3 to 22 kg. The surgical mortality was 2.5%. Justification for early primary repair was examined. Eleven patients underwent repair before 6 months of age (Group 1), 12 patients, between 7 and 11 months of age (Group 2), and 17 patients, after 12 months of age (Group 3). Degenerative changes in the atrioventricular valve increased significantly as age at repair increased (p less than 0.05 Group 1 versus Group 3). The incidence of residual mitral regurgitation tended to increase in the order of Group 1, 2 and 3, though the degree ranged from trivial to mild. Study of the left atrium/aorta ratio by echocardiography revealed that stable values of around 1.1 in Groups 1 and 2 and around 1.3 in Group 3 continued during the follow-up period of 3 years. Assessment of the diameter of the repaired mitral valve in the mean interval of 26 months in groups 1 and 2 revealed normal growth of the mitral valve annulus. The angle between the repaired mitral valve and ventricular septum, which can be affected by the growth of the ventricular septum, converged to normal range in the mean interval of 26 months. Postoperative pulmonary vascular resistance in Groups 2 and 3 was higher at 4.4 +/- 2.3 and 6.3 +/- 2.2, respectively, than in Group 1 at 3.3 +/- 2.2 (p less than 0.01 versus Group 3).(ABSTRACT TRUNCATED AT 250 WORDS)

Preservation of the pulmonary valve during intracardiac repair of tetralogy of Fallot.

From January 1981 to December 1990, intracardiac repair of tetralogy of Fallot in 148 pediatric patients, with one surgical death, was directed toward preservation of the native pulmonary valve. Using the accepted preoperative angiographic criterion for the pulmonary valve annulus area (PVA) of 1.8 cm2/m2, 85 patients were candidates for transannular right ventricular outflow patch (TAP). However, in 54 patients with a mean PVA of 1.5 cm2/m2 (range 1.06-1.76), the valve was preserved without using TAP because the morphological changes (cusp thickening and annular distensibility) seemed acceptable for preservation in view of its probable hemodynamic efficiency and growth potential. A morphological classification of pulmonary valve changes has evolved. Retrospectively, 24 (77%) of the 31 patients with TAP had moderate to severe cusp thickening and ring rigidity; this incidence was significantly higher (p < 0.001) than that in preserved patients (18 of 54 or 33%). The incidence of morphological changes increased with operative age; that is, 2 of 13 (15%) patients younger than 1 year versus 23 of 40 (58%) patients older than 4 years (p < 0.01). All 54 patients with preserved pulmonary valves were catheterized one month postoperatively. The intraoperative right to left ventricular systolic pressure ratio (RVP/LVP) decreased significantly (p < 0.005) in one month, from a mean of 0.79 (range 0.44-1.36) to 0.57 (range 0.36-0.97). The PVA increased from a mean of 1.5 to 1.9 cm2/m2 (range 1.20-2.65), and the rate of its increase was significantly larger (p < 0.005) as operative age decreased. Pulmonary valve regurgitation of greater than mild degree occurred in 8 of 54 (15%) patients with the valve preserved.(ABSTRACT TRUNCATED AT 250 WORDS)

Arterial switch operation for transposition of the great arteries: surgical techniques to avoid complications.

From June 1984 to November 1990, 109 patients with transposition of the great arteries underwent arterial switch operation. There were 5 deaths, yielding a mortality rate of 4.6%. During this period, modifications of the surgical technique were devised to minimize intra- and postoperative problems, such as bleeding, kinking of the coronary arteries, aortic regurgitation and pulmonary stenosis. The surgical refinements that evolved include (1) a more distal division of the ascending aorta, (2) a punch technique for reimplantation of the coronary arteries in a medially rotated position, approximating the commissure, and superior to the upper border of the sinus of Valsalva, and (3) removal of left coronary ostia by incision down from the transected site to include a button of aortic wall, avoiding the free margin of the aorta and patch enlargement of the neopulmonary artery. Since instituting these refinements: (1) the time consumed for hemostasis after termination of the bypass considerably decreased from 111 +/- 59 to 87 +/- 51 minutes (p less than 0.05), (2) the incidence of kinking of the coronary arteries decreased from 29% (4/14) to 7% (6/88) (p less than 0.05), and (3) the occurrence of aortic insufficiency 1 year after correction was reduced from 36% (5/14) to 8% (5/66) (p less than 0.02). However, the occurrence of pulmonary stenosis with a pressure gradient greater than 30 mmHg did not decrease significantly despite aggressive modifications of surgical techniques, and its incidence in the most recent series of 32 patients was still a high 19%.

[A total correction for tetralogy of Fallot without the use of homologous blood].

In 22 consecutive patients with tetralogy of Fallot (TF), a total correction was attempted without the use of a homologous blood transfusion from September 1995 to March 1997. The 22 patients were divided into two groups according to their surgical procedures; namely, either a simple correction (group I: n = 14) or a complex correction including the relief of peripheral pulmonary stenosis and/or the division of a previous systemic-pulmonary shunt (group II: n = 8). In 77% of all patients, surgery was performed without a homologous blood transfusion. No differences were found in the non-transfusion rate and the hematocrit (Ht) values between the two groups and, as a result, we thus confirm that this additional procedure is not a risk factor for surgery without a homologous blood transfusion. According to the correlation of the red blood cell volume before and after surgery, the preoperative Ht value corresponding to the postoperative Ht of 30% could be accurately predicted. The calculated Ht values were 41.0% in the patient weighing 15 kg, 42.5% in those weighing 10 kg, and 46.9% in those weighing 5 kg. These data suggest that a surgical correction without a homologous blood transfusion can therefore be safely performed in almost all patients with TF.

[Open heart surgery without the use of homologous blood in infants and young children: effectiveness of the intraoperative autologous blood donation from arterial monitoring line].

Open heart surgery without the use of homologous blood transfusion was attempted in 81 pediatric patients weighing 5.5-14.9 kg. Autologous blood was donated from arterial monitoring line after induction of anesthesia. This donated blood, actual volume of 9.2 +/- 1.7 ml/kg, was reinfused following the cessation of extracorporeal circulation. Hemodilution resulting from autologous blood donation was well tolerated by all patients. Sixty-eight patients (84%) were operated on successfully without the need for homologous blood. These data suggest that autologous blood donation from arterial monitoring line is a safe and effective method to avoid homologous blood transfusion especially in infants and young children undergoing open heart surgery.

[Anomalous origin of the right pulmonary artery from the ascending aorta: a report of three cases].

Three patients with anomalous origin of the right pulmonary artery from the ascending aorta were reported. Case 1 was a 16-day-old girl with the right pulmonary artery arising from the base of the ascending aorta. Division and direct anastomosis of the anomalous vessel to the pulmonary trunk were successfully performed. Case 2 was a 4-month-old girl with the kinked and stenotic right pulmonary artery arising from the distal ascending aorta. At the time of surgery, however, the right pulmonary artery had been completely occluded and the pulmonary hypertension of the main pulmonary trunk had been disappeared. The chest was closed without any corrections. Case 3 was a 17-month-old girl with the stenotic right pulmonary artery arising from the distal ascending aorta. The stenotic lesion of the right pulmonary artery was longitudinally incised and anastomosed with the PTFE graft in an end-to-end fashion, followed by the end-to-side anastomosis of the graft and the pulmonary trunk.

[Postoperative right ventricular function after repair of tetralogy of Fallot with respect to the method of right ventricular outflow tract reconstruction].

We evaluated postoperative right ventricular function in the sixty-four consecutive patients with tetralogy of Fallot underwent total correction. The patients were divided to three groups according to the method of right ventricular outflow tract reconstruction: transannular patching (TA group; n = 31); right ventricular outflow patching with preservation of pulmonary valve ring (RV group; n = 12) and transatrial-transpulmonary approach without right ventriculotomy (no-RV group; n = 21). The early results of postoperative cardiac catheterization and echocardiography were compared among the three groups. Degree of pulmonary regurgitation was significantly low in the RV group and no-RV group compared with TA group (p < 0.005). Right ventricular ejection fraction was the highest in the no-RV group (p < 0.002). The repair without right ventriculotomy for tetralogy of Fallot can provide the best results with respect to postoperative right ventricular function.

[Recommendation for open heart surgery in infancy].

Progress in infant open-heart surgery last 10 years was reviewed mainly based on the surgical experiences in Fukuoka Children's Hospital. Recent advances and present problems in patient's care, cardiopulmonary bypass methods and cardioplegia were discussed. Low surgical mortality of 4.8% in 245 infant open-heart repairs between 1988 and 1990 in Fukuoka is highly suggestive of early primary repair for most of congenital heart diseases.

[Current status of Jatene's operation].

The current status of Jatene's operation for transposition of the great arteries was described by showing the analysis of our results of an arterial switch operation addition to the review of the literatures. The arterial switch operation recently has become the operation of first choice because of its low surgical mortality (4.5% in author's series) and low incidence of postoperative complication. Surgical techniques to avoid complications such as postoperative bleeding, kinking of the transplanted coronary arteries, aortic valve insufficiency and pulmonary arterial stenosis were presented. One-stage anatomic correction has been performed with low mortality less than 10% in centers dealing high volumes of neonatal surgery (7% in author's series). One-stage correction in the neonate is advocated in views of its low surgical mortality and excellent postoperative left ventricular function.

[Successful surgical treatment by Konno aortoventriculoplasty in 2 cases of congenital aortic valvular stenosis].

Konno's aortoventriculoplasty was performed in two children aged 6 years and 10 years old with congenital aortic valvular stenosis. One had previous aortic valvotomy at 21 days of age. Preoperative peak systolic pressure gradients between the left ventricle and the aorta were 120 and 140 mmHg, respectively. The original diameter of the aortic valve ring were 12 mm and 16 mm and one had supra-annular aortic stenosis whose diameter was 7 mm. The 19 mm and 23 mm SJM prosthetic valves were inserted in the subcoronary position. The postoperative course was uneventful. Their ECG showed sinus rhythm with complete right bundle branch block. Both two patients made good recovery regarding clinical data and symptoms.