Angiocardiographic diagnosis of atresia of the right atrioventricular orifice and associated congenital heart defects

Ninety patients with atresia of the right atrioventricular orifice were examined. Their ages ranged from 3.5 to 24 years (9.9 +/- 0.5 years on the average). Stenosis of the pulmonary artery was found in 86 patients and was absent in 4 patients. Various intraarterial anastomoses had been established previously in 46 patients with stenosis of the pulmonary artery. All the patients were subjected to angiocardiographic examination including angiocardiography from the right and left parts of the heart and from the great vessels. Several anatomical variants of atresia of the right atrioventricular orifice and concomitant anomalies were studied. The following program of roentgeno-surgical examination in this complex congenital heart disease was elaborated. 1. Catheterization of the right and left parts of the heart and the great vessels. 2. Angiocardiography: right atriography; left ventriculography in anteroposterior, lateral, and, if indicated, axial views; aortography; pulmonary arteriography and, when indicated, right ventriculography.     

Atrioventricular groove patch plasty for anatomically corrected malposition of the great arteries.

OBJECTIVE: In anatomically corrected malposition of the great arteries, dextroposition of the posterior pulmonary artery and levoposition of the anterior aorta are associated with the leftward deviation of the proximal portion of the right coronary artery away from the right atrioventricular groove. This anatomic feature allows a transannular subpulmonary patch plasty of the right ventricular outflow tract along the right atrioventricular groove between the right coronary artery and the tricuspid anterior anulus (ie, atrioventricular groove patch plasty) for relief of subpulmonary stenosis without jeopardizing the right coronary artery. METHODS: This report describes the midterm results of a new surgical technique, atrioventricular groove patch plasty with a monocuspid transannular patch for subpulmonary stenosis, in 3 patients with anatomically corrected malposition of the great arteries, along with a concomitant closure of ventricular septal defects. RESULTS: Postoperative catheterization revealed adequate relief of pulmonary stenosis, with a pressure gradient of 8.0 +/- 3.5 mm Hg and with normalized right ventricular pressure (33 +/- 10 mm Hg), contributing to excellent midterm results with no late death and reoperation during a postoperative follow-up period of 70 +/- 47 months. CONCLUSION: This technique provides a promising alternative to Rastelli-type conduit repair for subpulmonary stenosis in anatomically corrected malposition of the great arteries.     

When should the hypoplastic right ventricle be used in a Fontan operation? An experimental and clinical correlation

Eight anesthetized dogs underwent closure of the tricuspid valve and a Fontan procedure, and the right ventricular cavity was reduced in stepwise fashion. There was an increase in right atrial pressure from 9.3 +/- 2.2 to 14.1 +/- 2.4 mm Hg (p less than 0.001), a decrease in pulmonary artery pulse pressure from 10.8 +/- 2.2 to 6.8 +/- 2.2 mm Hg (p less than 0.01), and a decrease in cardiac index from 2.7 +/- 0.3 to 2.2 +/- 0.2 L/min/m2 (p less than 0.001) when the ventricular size was dropped from 50% to 25% of normal. The difference between mean pulmonary artery pressure and mean right atrial pressure, which reflects the positive stroke work index of the ventricle, disappeared once the right ventricular cavity was reduced to 25% of normal (15.0 +/- 6.1 versus 14.1 +/- 2.4 mm Hg; p = not significant). Experimental results were correlated with postoperative catheterization data from 19 patients with tricuspid atresia who had the Fontan operation. Mean right atrial pressure was 18 +/- 4.6 mm Hg and cardiac index was 2.35 +/- 0.65 L/min/m2 in patients with a direct atrium-pulmonary artery anastomosis or an atrioventricular anastomosis with a right ventricular cavity less than 30% of normal versus 13 +/- 3.2 mm Hg and 3.42 +/- 0.46 L/min/m2 for those with an atrioventricular connection and a right ventricular cavity greater than 30% of normal (p less than 0.05 and p less than 0.02, respectively). The right ventricle enlarged from 27% +/- 6% of normal preoperatively to 35% +/- 10% of normal on follow-up (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

The hemodynamic effects and mechanism of action of pulmonary artery balloon counterpulsation in the treatment of right ventricular failure during left heart bypass

The efficacy of pulmonary artery balloon counterpulsation (PABC) was evaluated in improving right ventricular (RV) output during left heart bypass for global cardiac failure. In 13 pigs, a 40-ml balloon was positioned within a graft anastomosed to the pulmonary artery distal to the pulmonary valve, and left heart bypass was instituted from the left atrium to the carotid artery. Global myocardial failure was produced by an infusion of propranolol (range, 25 to 78 mg). In this model, RV output decreased despite volume loading to a right atrial pressure of 15 mm Hg and atrioventricular sequential pacing at 100 beats per minute. Pulmonary artery balloon counterpulsation increased both RV output (from 519 +/- 76 to 1,117 +/- 110 ml/min; p less than 0.01) and RV systolic stroke work (from 1.3 +/- 0.4 to 2.3 +/- 0.6 gm-m; p less than 0.01). Right atrial pressure decreased (from 15.5 +/- 0.9 to 10.7 +/- 1.0 mm Hg; p less than 0.01) in 8 of the pigs studied during RV failure. In 5 pigs, ventricular fibrillation occurred without a stable model of RV failure, and there was no cardiac output before or after counterpulsation. The mechanism of action of PABC was studied by placing a flow probe around a large branch of the right pulmonary artery. During RV failure, balloon inflation caused flow through the pulmonary circulation, and ventricular systole resulted in filling of the graft. During ventricular fibrillation, balloon inflation and deflation produced only a to-and-fro movement of blood in the pulmonary artery branch without net forward flow.(ABSTRACT TRUNCATED AT 250 WORDS)     

Outcome after reconstruction of discontinuous pulmonary arteries

OBJECTIVE: This study was undertaken to determine outcomes of and optimal treatment strategies for reconstruction of congenital or acquired discontinuity of branch pulmonary arteries. METHODS: Between 1985 and 2000 pulmonary artery continuity was established in 102 patients with discontinuous central pulmonary arteries and normal peripheral arborization. Data were obtained retrospectively. RESULTS: Techniques to connect both pulmonary arteries included direct pulmonary artery-pulmonary artery anastomosis (n = 33), tube graft interposition (n = 47), or pulmonary arterial implantation in right ventricular-pulmonary arterial conduits (n = 22). Among patients with biventricular repair (n = 66), survival was 85% +/- 8% at 5 years, and freedom from surgical or interventional pulmonary arterioplasty was 31% +/- 11%. At most recent follow-up, mean branch pulmonary arterial z scores were -0.5 +/- 1.6 (right pulmonary artery) and -1.4 +/- 1.3 (left pulmonary artery). Mean right to left ventricular pressure ratio was 0.61 +/- 0.26, and this value was more than 0.75 in 13 of 58 cases. Fifteen of 51 had a lung perfusion mismatch of more than 75:25, and in 9 of 58 one branch pulmonary artery was occluded. Twenty-two patients who underwent primary establishment of antegrade pulmonary artery flow without previous shunt procedures had comparable survival and reintervention rates, with a tendency toward higher pulmonary arterial z scores and lower right to left ventricular pressure ratios. Among patients with single-ventricle repair (n = 33), 5-year survival was 93% +/- 8% and freedom from pulmonary arterioplasty was 39% +/- 9%. Ten of 19 patients had a lung perfusion mismatch, and one branch pulmonary artery was occluded in 4 of 31. Overall, a direct pulmonary artery anastomosis was associated with better survival (P =.006). The presence of aortopulmonary collaterals was a risk factor for pulmonary artery occlusion (P =.03). CONCLUSION: Good survival can be achieved for patients with pulmonary artery discontinuity, but this requires frequent reinterventions. Direct pulmonary artery- pulmonary artery anastomoses and control of all collateral vessels may further improve outcome.     

Surgical repair of coronary sinus orifice atresia with persistent left superior vena cava in heterotaxia

A 6-month-old boy was diagnosed with coronary sinus orifice atresia, double-outlet right ventricle, complete atrioventricular septal defect, pulmonary stenosis, and moderate common atrioventricular valve regurgitation associated with heterotaxy syndrome. Cardiac venous flow drained through a persistent left superior vena cava. We decided to perform coronary sinus orifice unroofing through the right atrium under a guide using a bougie. The persistent left superior vena cava was divided. Bidirectional Glenn anastomosis and edge-to-edge common atrioventricular valve repair were concomitantly performed. After a 1-year follow-up period, the patient is alive and well without any ischemic event.     

Intrauterine creation and repair of pulmonary artery stenosis in the fetal lamb. Weight and ultrastructural changes of the ventricles

Fetal lamb experimental models were employed for intrauterine creation and repair of pulmonary artery stenosis. The study group was composed of 51 fetal lambs including 29 models of pulmonary artery stenosis and 22 control lambs. Gestational age was 89 days at creation of pulmonary artery stenosis. Fourteen fetal lambs (Group A) were studied after creation of the stenosis at 131 days of gestation and compared to normal age-matched control lambs. The systolic right ventricular pressure was significantly higher after creation of pulmonary artery stenosis (76.6 +/- 17.8 versus 50.3 +/- 23.5 mm Hg), but the systolic pulmonary artery pressure was unchanged. The mean right ventricular weight and the mean right ventricular/left ventricular weight ratio were significantly greater after pulmonary artery stenosis than in normal control animals. The transverse myocyte diameter was not modified by pulmonary artery stenosis, but on electron microscopic study the myocytes appeared mature. Ten lambs (Group B) underwent intrauterine repair of pulmonary artery stenosis at 131 days of gestation without cardiopulmonary bypass. The pulmonary artery was clamped and patched. Immediately after repair the right ventricular pressure fell significantly from 85.8 +/- 18.9 to 62.2 +/- 14.6 mm Hg. At birth, 7 +/- 6 days after repair, Group B was compared to Group C (unrepaired pulmonary artery stenosis, five fetuses) and to normal control lambs. The mean right ventricular weight and the mean right ventricular/left ventricular weight ratio were not statistically different in Group B and in the control group. There were no ultrastructural changes after intrauterine repair. We conclude that intrauterine creation of pulmonary artery stenosis causes right ventricular hypertrophy with more mature myocytes. Intrauterine repair of pulmonary artery stenosis is feasible without cardiopulmonary bypass and rapidly abolishes the preponderance of right ventricular weight over left ventricular weight.     

Fontan type operation for complex lesions. Surgical considerations to improve survival

Twenty-five of 49 patients who underwent a Fontan type operation had complex lesions other than tricuspid atresia with ventriculoarterial concordance. Three patients had significant subaortic stenosis. Thirty-four palliative operations, including nine Glenn shunts, were performed before the Fontan operation. Direct atriopulmonary anastomosis was performed in 21 patients. In four, valved conduits were used. Twelve patients had right atrioventricular valve patch closure (three had running and nine had interrupted suture technique). On the basis of the presence of increased or decreased pulmonary blood flow before any surgical intervention, patients were divided into Group 1 (previous pulmonary artery banding, N = 8) and Group II (pulmonic stenosis, N = 17). Postoperatively, in Group I, 87% had significant effusions, mean right atrial pressure was higher (20.6 +/- 6.5 torr), and hospital stay longer (31 days). In Group II, 40% had significant effusions, mean right atrial pressure was lower (16.5 +/- 4.3 torr), and hospital stay shorter (15 days). Significant atrioventricular valve patch disruption occurred in three patients (two had running suture technique), and conduit occlusion occurred in two. Four patients (three with subaortic stenosis and pulmonary artery banding) without an established Glenn shunt required Fontan takedown for persistent low cardiac output, two of whom died (2/25 or 8%). There were three late deaths (3/23 or 13%). Nineteen of 20 surviving patients observed from 2 months to 6 years are doing well. We believe that early Fontan takedown in patients with persistent low cardiac output, interrupted suture technique for atrioventricular valve closure, avoidance of valved conduits, and a preliminary Glenn shunt in patients with pulmonary artery banding and/or subaortic stenosis can further improve the results with the Fontan operation for complex lesions.     

The Contegra conduit in the right ventricular outflow tract induces supravalvular stenosis

OBJECTIVE: We sought to evaluate the incidence and nature of pulmonary stenosis after implantation of the bovine jugular vein graft (Contegra; Medtronic, Inc, Minneapolis, Minn) in the right ventricular outflow tract. METHODS: Between May 2000 and September 2002, 58 Contegra conduits (8-22 mm) were implanted during primary (n = 27) or redo operations (n = 31) in 57 patients, with ages ranging from 2 days to 48 years (mean, 9 years). Indications were truncus arteriosus (n = 16), tetralogy of Fallot (n = 28), pulmonary replacement in the Ross operation (n = 10), and Rastelli-type repair for double-outlet right ventricle (n = 4). Echocardiography was prospectively performed by a fixed team of investigators during follow-up (mean, 22.7 +/- 10 months). A peak gradient of greater than 50 mm Hg was considered severe stenosis. RESULTS: Two patients died from Staphylococcus aureus -induced septicemia and enterococcal endocarditis after 12 days and 12 weeks, respectively. One patient died of heart failure caused by endocardial fibroelastosis after 1 year. Freedom from severe stenosis at the distal anastomosis was 91% +/- 3% at 3 months, 68% +/- 6% at 12 months, and 49% +/- 8% at 24 months. The risk of development of stenosis does not change over time. Younger age and its derivatives (graft size and indication) are significantly related to the occurrence of severe stenosis ( P < .0001). Seventeen (29%) conduits required an endovascular intervention (balloon dilatation or stent). Seven (12%) conduits were explanted (endocarditis, 2; stenosis, 5). Histologic analysis of the explanted conduits showed excessive proliferation of neointima at the level of the distal anastomosis. Valve regurgitation was observed in 9 (16%) conduits and was always secondary to dilatation in the presence of severe distal stenosis. CONCLUSION: The Contegra conduit induces a neointimal proliferation at the level of the pulmonary anastomosis. This leads to a high incidence of severe stenosis at intermediate-term follow-up.     

Successful Repair of the Right Atrial Isomerism, Double Outlet Right Ventricle, Cornmon Atrioventricular Canal, Pulmonary Stenosis, and Total Anomalous Pulmonary Venous Connection

A 6-year-old boy was successfully operated on for double outlet ventricle, common atrioventricular canal with severe valvular regurgitation, right atrial Isomerism, L-loop ventricles, total anomalous pulmonary venous connection, and pulmonary stenosis with hypoplastic left pulmonary artery. The Interventricular rerouting from the left ventricle to the ascending aorta was performed with a spiral patch, the lnteratrlal switching was performed by a Mustard patch, the common atrioventricular orifice was partitioned and valve repair was performed, and an 18-mm valved conduit was inserted between the right ventricle and the pulmonary artery. Although the patient had a small residual ventricular septal defect and pulmonary stenosls, the patient Is alive and well.     

Autogenous pericardial patch augmentation of the anastomotic orifice of Blalock-Taussig shunt]

Our recent experiences of the autogenous pericardial patch augmentation of Blalock-Taussig anastomotic orifice are reported. In Case 1, the direct suture between the left subclavian artery and the left pulmonary artery was difficult on the anterior wall because of the shortness of the left subclavian artery. Therefore, a piece of the patient's own pericardium was excised and sutured anteriorly between the two vessels by interrupted 7-0 polypropylene sutures. A 19 months postoperative angiogram showed so-called parrot-beaking of the subclavian artery probably due to tension, but there was no distortion or stenosis of the pulmonary artery. In Case 2, the right subclavian artery distal to the bifurcation of the vertebral artery was longitudinally split measuring approximately 2.5 cm in length, and widened by a piece of the autogenous pericardium in a wedge shape. Then, it was anastomosed to the right pulmonary artery without undue tension. Seven months postoperatively the patient died from severe AV valve regurgitation. The autopsy showed widely patent anastomosis and good healing as well as slight expansion of the pericardial patch but without aneurysm formation. In Case 3, the same operation as in Case 2 was performed. A 6 months postoperative angiogram showed no stenosis or distortion of either the subclavian or the pulmonary artery. Although it is premature to draw any conclusion, the use of the autogenous pericardium may be indicated to widen the anastomotic orifice of Blalock-Taussig shunt without sacrificing the length of the subclavian artery even in small infants or neonates.     

Results of the Lecompte procedure in malposition of the great arteries and pulmonary obstruction.

OBJECTIVE: Assessment of the Lecompte procedure, our repair method of choice in malposition of the great arteries with pulmonary stenosis. METHODS: A retrospective analysis of 42 patients (median age at operation, 1.4 years) operated on between 1986 and 1999 for various forms of great artery malposition, ventricular septal defect, and pulmonary stenosis. Relevant associated findings included the insertion of a tricuspid papillary muscle on the conal septum (nine patients), absence of conal septum (six patients), hypoplasia of a side pulmonary artery (four patients), and hypoplasia of the right ventricle (one patient). A preliminary systemico-pulmonary shunt was created in 28 patients and a cavo-pulmonary anastomosis in one patient. At operation, the conal septum (whenever present) was resected (36 patients), the pulmonary bifurcation was usually translocated over the ascending aorta (37 patients), and the main pulmonary artery was enlarged with a patch of pericardium. A monocusp valve was fashioned within the patch in 40 patients. The follow-up information was complete in 32 patients and ranged from 0.4 to 14 years (mean, 5.4+/-3.2 years). RESULTS: The survival rate at 5 years was 92+/-5%. Three patients died post-operatively (mortality, 7%) and none during follow-up. The freedom from reoperation was 86+/-8 and 51+/-22% at 5 and 10 years, respectively. Six patients were reoperated, all for a pulmonary stenosis. Calcification of the monocusp patch was present in all. Pulmonary stenosis developed in three further patients: one underwent percutaneous dilatation and two are awaiting surgery. No procedural factors thought to have a potential correlation with the development of right ventricular outflow tract stenosis could be individualized on univariate analysis. CONCLUSIONS: The Lecompte procedure, which allows early repair of these defects, provides overall good results. The need to reoperate on the right or left ventricular outflow tract seems reduced in comparison with the Rastelli operation, the other alternative.     

Canine heart-lung transplantation after twenty-four-hour hypothermic preservation with Belzer-UW solution

Twenty four-hour heart-lung preservation with Belzer-UW solution was studied in the canine heterotopic heart-lung transplant model. Four pairs of mongrel dogs were used. The donor heart was arrested with cardioplegic solution. The heart and the lung were flushed with UW solution, then excised en bloc and immersed in 4 degrees C UW solution for 24 hours. The graft was transplanted heterotopically into the left pneumonectomized recipient. The transplant procedure consisted of end-to-end anastomosis of two left main bronchi, end-to-side anastomosis of the descending aortas, and end-to-end anastomosis of the donor's superior vena cava to the recipient's left pulmonary artery. The recipient's right pulmonary artery was ligated after an observation period, and cardiopulmonary functions were measured during room air ventilation. In all four transplanted dogs the grafts were able to sustain the recipient's circulation. The prepreservation and posttransplant cardiac output was 71.2 +/- 21.6 ml/min/kg and 96.4 +/- 44.4 ml/min/kg; the arterial PO2 was 80.8 +/- 12.9 mm Hg and 74.1 +/- 2.7 mm Hg; and the arterial PCO2 was 25.6 +/- 5.5 mm Hg and 35.9 +/- 13.3 mm Hg, respectively. There were no significant differences between the prepreservation and posttransplant values. Posttransplant myocardial water content was within the normal range. Pulmonary vascular resistance increased significantly, to 13.8 +/- 3.7 from 8.8 +/- 5.2. Wood units, and the wet/dry ratio of the lung increased significantly, to 8.3 +/- 1.6 from 4.4 +/- 0.6. In conclusion, heart-lung grafts preserved in UW solution for 24 hours were able to sustain the recipient's circulation. Significant pulmonary edema, however, could not be prevented.     

Bidirectional cavopulmonary anastomosis using vertical vein for right isomerism, pulmonary atresia, and TAPVR

An 8-year-old girl who was diagnosed as having right atrial isomerism, pulmonary atresia, butterfly-shaped juxtaductal pulmonary arterial stenosis, total anomalous pulmonary venous return of the supracardiac type, regurgitant common atrioventricular valve, and univentricular heart of the right ventricular type underwent bilateral, bidirectional cavopulmonary anastomosis using a vertical vein and anastomosis between the common pulmonary venous trunk and atrium. The surgical procedure in this patient is described.     

Anatomic variation of the right hepatic artery and its reconstruction for living donor liver transplantation using right lobe graft

We analyzed the anatomy and reconstruction of the right hepatic artery (RHA) in 96 cases of adult-to-adult living donor right liver transplantations, during 2002. Most right livers had a single orifice (n = 185, 96%). Seven right livers (4%) showed multiple arteries, namely a replaced artery in five cases and accessory arteries in two cases. Three liver grafts had two separate orifices: both arterial stumps were reconstructed in one case, and accessory arteries were ligated in two cases because of sufficient back bleeding. The mean diameter of the graft RHA was 2.4 mm (1-4). More than 60% (59 of 96) of graft arteries were anastomosed with distal branches of recipient RHA for size matching. Eleven graft arteries were anastomosed to vessels other than the RHA, namely the left hepatic artery [LHA] in eight right gastroepiploic artery in three: for size matching in five and due to previous injury of RHA in six. Five cases showed significant size-mismatches of more than twofold. The median follow-up period was 270 days. In one patient, an intramural thrombus developed on postoperative day 3 requiring a revision of the anastomosis. In another patient, arterial stenosis occurred on postoperative day 16 a time when collateral arteries had developed. The overall complication rate related to arterial reconstruction was 2%. In conclusion, with precise knowledge of the anatomy, an adequate selection of recipient arterial stump, and an experienced technique, a desirable result may be achieved in right lobe transplantation.     

Unilateral absence of a pulmonary artery in absent pulmonary valve syndrome: a case report and review of literature.

A six-year-old boy presented to the Cardiology clinic with history of mild cyanosis and dyspnea on exertion from age 1. He had a to-and-fro murmur at the middle left sternal border. Chest examination was normal but chest x-ray showed a small left lung. Echocardiography established the diagnosis of tetralogy of Fallot (TOF) and absent pulmonary valve with severe pulmonary regurgitation and moderate stenosis at the pulmonary valve site. There was severe dilatation of the main and right pulmonary arteries. The left pulmonary artery (LPA) could not be seen. Angiography failed to show a LPA. This case of an absent LPA associated with absent pulmonary valve syndrome is discussed and the literature is reviewed.     

A case of racemose hemangioma of the right bronchial artery and intercostal to pulmonary arterial anastomosis

We reported a case of racemose hemangioma of the bronchial artery and intercostal to pulmonary arterial anastomosis. A 67-year-old woman was admitted because of repeated hemoptysis. Bronchoscopic examination revealed a torous lesion of the right B⁷ bronchus. Intercostal angiography demonstrated communications between right dilated, meandered intercostal arteries and right pulmonary artery. Bronchial angiography showed dilatation and convolution of the right bronchial artery. Angiographic embolization of the right bronchial artery and the right intercostal artery was underwent. There was no recurrence of hemoptysis one year after the embolization procedure. We think that angiographic embolization is an effective method of treatment of hemoptysis due to racemose hemangioma of the bronchial artery and intercostal to pulmonary arterial anastomosis.     

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.     

Management of congenital stenosis of a branch pulmonary artery with balloon dilation angioplasty. Report of 52 procedures

Twenty-four children, aged 4 months to 16 years (nine patients 2 years old or younger), underwent balloon dilation angioplasty of hypoplastic or stenotic branch pulmonary arteries between July, 1981, and April, 1984. Most children had tetralogy of Fallot, with or without pulmonary atresia, or isolated peripheral pulmonary artery stenosis. Fifty-two dilations were attempted, 44 in the catheterization laboratory and eight in the operating room. Of these, 26 (50%) were judged successful; the average vessel diameter on angiogram increased from 4.1 +/- 0.3 to 7.2 +/- 0.3 mm (76%), the gradient across the narrowed segment fell from 60 +/- 10 to 36 +/- 5 mm (40%), pressure in the main pulmonary artery or right ventricle proximal to the obstruction decreased from 83 +/- 10 to 66 +/- 6 mm Hg (20%), and the radionuclide-determined fraction of cardiac output directed to the lung ipsilateral to the dilated pulmonary artery increased from 40 +/- 4 to 51 +/- 4 (28%). All changes were significant at the p less than 0.005 level. Reasons for failure included inadequate technique (balloon too small, inability to position balloon or wire) in 14 and the refractory nature of the lesion itself in 11. Technical failures were age independent. Nondilatable lesions were more common in children more than 2 years old (10/25 versus 1/10) or with isolated peripheral pulmonary artery stenosis (5/7). Five of seven stenoses near previous shunts were nondilatable. One child exsanguinated when the pulmonary artery ruptured during dilation, but other complications were few. Eight dilations, followed up for an average of 6 months after dilation, showed angiographic persistence of improvement; two of four lesions were successfully redilated to a larger size. Balloon dilation angioplasty appears beneficial, both short and long term, for some patients with hypoplastic or stenotic branch pulmonary arteries, especially if performed early in life.     

Bidirectional cavopulmonary anastomosis in patients under two years of age.

Between December 1986 and December 1990, a bidirectional cavopulmonary anastomosis was performed in 27 patients younger than 2 years of age, including 12 with heterotaxia syndrome. Age and weight of patients averaged 14.2 +/- 6.6 months and 8.1 +/- 2.2 kg, respectively. Eleven had pulmonary atresia and 16 had pulmonary stenosis. The main pulmonary artery was ligated in seven patients in the latter group (subsequently reopened in one) and left open in nine (subsequently ligated in two). There were four hospital deaths (15%). All patients were discharged with anticoagulant/antithrombotic therapy to be continued for 6 months. There were two late deaths before further operations (8.7%). Two patients, one with acquired massive pulmonary arteriovenous fistulas and one with progressive common atrioventricular valve regurgitation, subsequently underwent definitive repair (biventricular in one), and both died. Heterotaxia syndrome (p = 0.087) and preoperative mean pulmonary artery pressure higher than 15 mm Hg (p = 0.09) were the only risk factors for overall mortality.