Current status of the surgical treatment of truncus arteriosus

Persistent truncus arteriosus: pathologic anatomy in 54 cases

Fifty-four specimens of heart with persistent truncus arteriosus (PTA) were reviewed anatomically. According to the Collett-Edwards classification there were 28 examples of type I and 26 type II. The sex distribution was equal. The number of the truncal cusps ranged from one to four (42% tricuspid, 30% bicuspid, 24% quadricuspid, and 4% unicommissural). A unicommissural truncal valve has not been previously reported. In 72% of cases, the truncal valve leaflets were thickened or dysplastic. Two valves were stenotic. The truncus arteriosus originated from both ventricles equally in 42% of the cases, predominantly from the right ventricle in 42%, and predominantly from the left ventricle in 16% of the cases. In unoperated cases of PTA originating predominantly from the right ventricle, it appeared to us that usual operative correction might result in left ventricular outflow obstruction. Variations in coronary arterial origins and patterns were present in nearly half of the cases. A single coronary artery was observed in ten cases (18.5%). Stenosis of the ostium of one coronary artery was seen in each of four cases (7%). High posterior origin of the left coronary artery was observed in ten cases (18.5%). Among the associated cardiovascular anomalies, the most common were right aortic arch (36%) and interruption of the aortic arch (11%). Three cases with the latter condition exhibited crossed pulmonary arteries. Isolated cases with tricuspid atresia, vascular sling (left pulmonary artery arising from right pulmonary artery), and persistent common atrioventricular canal were encountered.

Factors associated with outcomes of persistent truncus arteriosus

OBJECTIVES

The purpose of this study was to identify trends and factors associated with outcomes of persistent truncus arteriosus (PTA).

BACKGROUND

Although there have been significant improvements, PTA continues to be associated with significant morbidity and mortality.

METHODS

We undertook a review of all consecutive cases of PTA (n = 205) presenting at our institution from 1953 to 1997. Data were collected regarding demographics, anatomy, management (surgical palliation and repair) and outcomes (mortality and reoperation).

RESULTS

Significant trends (p < or = 0.001) related to groups defined by year of birth were as follows: number of cases (1953-1967, n = 13; 1968-1977, n = 42; 1978-1987, n = 69; 1988-1997, n = 81), median age at first assessment (8 months, 42 days, 7 days and 2 days, respectively), proportion who did not have any surgery (58%, 27%, 22% and 11%), proportion who had an initial palliative procedure (25%, 37%, 6% and 2%), proportion who underwent PTA repair (31%, 59%, 72% and 88%), median age at PTA repair (11.2 years, 1.1 years, 1.6 months and 12 days) and proportion dying before hospital discharge after repair (50%, 63%, 56% and 41%). Since 1995, mortality before hospital discharge after repair has further decreased to 2/11 (18%). Increasing time to initial conduit replacement in hospital survivors was significantly related to larger sized conduit at repair (p = 0.02) and use of pulmonary homografts (vs. aortic homografts or xenografts; p = 0.002). Interventional catheterization to address conduit obstructions significantly increased conduit longevity.

CONCLUSIONS

Significant improvements in PTA outcomes are evident with trends toward earlier age at assessment and complete repair.

Successful correction of a Collett Edwards type II truncus arteriosus after bilateral pulmonary artery banding--a case report

A case of a 4-year-old girl who underwent successful correction of a Collett Edwards type II truncus arteriosus following bilateral pulmonary artery banding is reported herein. The diagnosis of Collett Edwards type II truncus arteriosus was made when she was 5 months of age, after which the bilateral pulmonary artery banding was performed. This proved very effective and enabled elective radial surgery to be done. The radical operation was performed safely by a modified version of Rastelli's procedure. The patient had an uneventful recovery and is now well with no symptoms one year following her operation.

Internal banding for palliation of truncus arteriosus in the neonate

A method for surgically limiting pulmonary blood flow in the critically ill neonate with truncus arteriosus is described. Two recent cases utilizing this technique are presented. Comparisons are made between this and other palliative surgical procedures used in truncus arteriosus.

Balloon dilatation of stenotic right ventricle-to-pulmonary artery conduits

In seven children with obstructed right ventricle-to-pulmonary artery conduits, balloon dilatation (BD) was performed 10-58 months after insertion of the conduit. Average valve gradient was reduced from 69 to 32 mmHg. Obstruction at the conduit-branch pulmonary artery connection became apparent after dilatation of the valve; these distal stenoses also were dilated. It is concluded that the useful lifetime of a right ventricle (RV) to pulmonary artery (PA) conduit may be extended by BD of an obstructed biological valve and/or BD of a stenotic conduit-pulmonary artery anastomosis.

Surgical treatment for the type II and III truncus: complete division of the truncal root with primary repair using absorbable suture

A simplified technique for repair of type II and III truncus arteriosus applicable in neonates is described. The method is particularly useful in those patients in whom the pulmonary artery orifices arise from the posterior wall of the truncal root. Advances in two-dimensional echocardiography have provided an accurate means of determining the exact anatomy preoperatively. At operation, isolation of the pulmonary orifices on a button of posterior truncal wall is accomplished by complete division of the main truncal root. Primary closure of the new ascending aorta is made possible by extensive mobilization of the aorta and pulmonary orifices. Early postoperative follow-up indicates that the use of a new absorbable suture for primary repair of the aortic root allows for normal growth.

Surgical experience with persistent truncus arteriosus in symptomatic infants under 1 year of age. Report of 13 consecutive cases

Between January 1974 and November 1980, 13 symptomatic infants under 1 year of age with persistent truncus arteriosus type I or II underwent surgery. Pulmonary artery banding was performed in 10 cases, with five deaths. Among the survivors, one developed severe pulmonary vascular disease and only two underwent late intracardiac repair. Primary total correction was performed in three infants and all are well, though one required conduit replacement five and a half years after the initial procedure. Recently, antibiotic sterilised homograft conduits, rather than heterografts, have been preferred as extracardiac conduits in infancy. Early intracardiac repair followed, if necessary, by later conduit replacement appears to have significant advantages over "conventional" pulmonary artery banding and late total correction. Concern remains on the treatment of choice in infants under 3 months of age.

Surgical correction of pulmonary atresia with multiple large systemic-pulmonary collaterals

A young patient in whom the pulmonary blood flow was supplied completely by five systemic-pulmonary collaterals underwent reconstruction of the pulmonary outflow tract by a new technique. This consisted of the insertion of a valve-bearing conduit between the right ventricle and an isolated segment of the descending aorta, which gave rise to three of the collaterals. Although the patient had a hypoplastic pulmonary artery confluence, other factors mitigated against its use as the sole conduit for right ventricular output.

Congenital heart disease in the first month of life

During the years 1963--73, 276 children with congenital heart disease were admitted to this hospital during their first month of life. Ventricular septal defect was the most common cardiac anomaly and this lesion, together with transposition of the great arteries, comprised 35% of all cardiovascular malformations. Extracardiac malformations were found in 86 patients. The cumulative survival rate for all patients was 66% in the first month of life and 33% in the first year. Forty-three patients were operated upon, but it is estimated from necropsy reports and available clinical data that another 74 patients, who died without operation, would have been suitable candidates for total corrective surgery.

Surgical treatment of persistent truncus arteriosus in the first year of life

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Truncus arteriosus with unilateral absence of a pulmonary artery. Criteria for operability and surgical results

In 15 of 126 (12%) patients with truncus arteriosus who were catheterized at the Mayo Clinic from 1967 through 1975, natural agenesis of one pulmonary artery was present. Ten truncus patients with either natural or acquired absence of one pulmonary artery have undergone definitive operation. The criteria for operability, based on a calculation of pulmonary resistance, are different in patients with single pulmonary artery than in patients with two pulmonary arteries. Study revealed that, if the calculated pulmonary resistance in the patient with single pulmonary artery is halved, this new value provides a more reliable assessment of the reactivity of the pulmonary arteriolar bed than does the total calculated pulmonary resistance value. Follow-up information suggests that the patient with single pulmonary artery may be at potentially high risk of continued progression of pulmonary vascular disease after surgical correction, possibly because of the postoperative obligatory increased flow through the single pulmonary arteriolar bed as a result of the entire cardiac output passing through it. Surgical correction of truncus arteriosus during infancy, before significant pulmonary vascular disease has developed, appears to be particularly desirable in this subgroup of patients with single pulmonary artery.

Truncus arteriosus and previous pulmonary arterial banding: clinical and hemodynamic assessment

Twenty-seven patients with truncus arteriosus and previous pulmonary arterial banding were evaluated 1 1/2 to 14 years (mean 7 years) after banding. Ages at the time of cardiac catheterization ranged from 3 to 18 years (mean 9 years). Current symptoms were severe in five patients and were related to truncal valve incompetence or decreased pulmonary blood flow (or both) rather than to age, duration of palliation or band location. Twenty-one of 22 patients with two pulmonary arteries were considered to be in a hemodynamically operable state at the time of study. The condition of three of five patients with a single pulmonary artery was subsequently found inoperable because of severe pulmonary vascular disease in the lung supplied by the single pulmonary artery. In patients with two pulmonary arteries, demonstration of low pressure in at least one normal-sized pulmonary artery established operability. Postoperative pressure measurements correlated well with preoperative prediction of operability, with 19 of 20 patients having a pulmonary arterial pressure less than 70 percent of systemic levels after repair. Bilateral pulmonary arterial binding may be more effective than central arterial banding (which frequently produces severe obstruction to the right pulmonary artery) in preventing pulmonary vascular obstructive disease in patients with truncus arteriosus who have two pulmonary arteries. Patients with truncus arteriosus and a single pulmonary artery with pulmonary arterial banding remain at high risk for the development of pulmonary vascular obstructive disease.

The natural history of truncus arteriosus

The cases of 23 patients whose condition was diagnosed as truncus arteriosus, type I or II, and who were seen at the Mayo Clinic during the decade preceding 1967, that is, before corrective operation became feasible, were reviewed. Ten were infants (through one year of age), and all ten have died. Eight ranged in age from more than one year through seven years of age, and all are living, except one, who diet 11 years after diagnosis. Five were older than seven years, and all had severe pulmonary vascular obstructive disease; three have died. Thus, 14 of the 23 have died, and all but one surviving patient have mild to moderate disability. The generally grave prognosis for patients with truncus arteriosus warrants continued use of corrective operation, but suggests that the greatest benefit can be realized by successful correction in the infant with congestive heart failure and in early childhood before the development of severe pulmonary vascular obstructive disease.