Management strategy for very mild aortic valve stenosis.

It is unclear how often patients with very mild aortic stenosis (gradients < 25 mmHg) need interval follow-up. The purpose of this study was to define the determinants of disease severity progression and to propose appropriate management strategies. It is known that congenital aortic stenosis is a progressive disease that requires long-term follow-up at consistent intervals. We studied 89 patients with very mild aortic stenosis. Cox proportional hazard modeling was performed to ascertain predictors of morbidity and mortality. Events were defined as valve surgery or death. Of the original 89 patients, 7 died (92% survival); one death was sudden and unexplained and six were noncardiac. Eighteen individuals were lost to follow-up (10 not located and 8 refused participation). Twelve (17%) had valve surgery. The minimum time interval between initial diagnosis of very mild aortic stenosis and surgery was 4.6 years (mean, 14.0). Age at diagnosis, gender, initial gradient, initial gradient/age, and aortic regurgitation were found not to be predictive of outcome. However, the slope of the transaortic gradient [change of gradient/time (years)] was predictive of outcome (hazard ratio of 1.69; confidence interval, 1.4-2.2). At least 17% of these patients progress to require operation. For patients with a gradient slope < 1.1, evaluation every 4 or 5 years is recommended. For patients with a gradient slope > 1.2, evaluation every 1 or 2 years seems prudent.

Valve-sparing operation for balloon-induced aortic regurgitation in congenital aortic stenosis.

OBJECTIVE: Aortic regurgitation after balloon dilation of congenital aortic stenosis may be treated with valve repair as an alternative to replacement. METHODS: Charts and echocardiograms of all patients undergoing aortic valve operations after balloon dilation of congenital aortic stenosis at our institution between January 1988 and December 1999 were reviewed. RESULTS: Twenty-one patients underwent valvuloplasty for predominant aortic regurgitation 9 months to 15 years (mean, 6.1 years) after balloon dilation. The mean +/- SD age at the time of the operation was 11 +/- 7 years. Aortic regurgitation was caused by a combination of commissural avulsion (10), cusp dehiscence with retraction (9), cusp tear (5), central incompetence (2), perforated cusp (1), or cusp adhesion to the aortic wall (1). Repair techniques included commissural reconstruction with a pericardial patch (8), pericardial patch cusp augmentation (6), primary suture repair (6), raphae release and debridement (4), commissurotomy (4), commissural resuspension with sutures (3), and cusp release (1). There were no deaths. At a mean follow-up of 30.1 months (range, 9 months-8 years), all patients were asymptomatic, and the grade of aortic regurgitation had been significantly reduced (P <.001). Left ventricular end-diastolic dimension z scores and proximal regurgitant jet/aortic anulus diameter ratios were significantly reduced (P <.001) and remained so over time. Freedom from reoperation for late failure was 100%, and overall freedom from reintervention was 80% at 3 years. CONCLUSION: Aortic valve repair for balloon-induced aortic regurgitation is reproducible and durable at medium-term follow-up.

Surgical management of mitral regurgitation after repair of endocardial cushion defects: early and midterm results.

BACKGROUND: Mitral regurgitation (MR) represents the principal indication for reoperation in patients after repair of atrioventricular septal defects (AVSD). Reports of mitral valvuloplasty (MVP) in such patients are few; the alternative, mitral valve replacement (MVR), necessitates commitment to future valve replacement and long-term anticoagulation. We sought to determine the outcome of those patients who underwent either MVP or MVR between January 1, 1988, and December 31, 1998, for significant MR after repair of AVSD. Furthermore, we sought to identify (a) morphological predictors necessitating MVR, and (b) predictors of future reoperation within the MVP group. METHODS AND RESULTS: Retrospective review of clinical, operative, and echocardiographic data were performed. There were 46 patients identified (37 MVP and 9 MVR). The median age at initial AVSD repair was 0.6 years, and the age at subsequent mitral valve operation was 2.8 years. The early postoperative mortality rate was 2.2%, and survival at 1 and 10 years was 89.9% and 86.6%, respectively. A high rate of complete heart block was noted within the MVR group (37.5%). Freedom from later mitral valve reoperation for both groups was similar. No significant morphological predictors necessitating MVR were found. Predictors of reoperation within the MVP group included the presence of moderate or worse MR in the early postoperative period. In both groups New York Heart Association class, degree of MR, growth, and ventricular volumes improved. CONCLUSIONS: Mitral valve surgery significantly improves clinical status, with a sustained improvement in ventricular chamber size. MR can be successfully managed in patients after repair of AVSD independent of morphological type. Overall survival is acceptable, and further reoperation within the MVP group is influenced by early outcome of repair.

Pulmonary artery trauma due to balloon dilation: recognition, avoidance and management.

OBJECTIVES: We reviewed the management and outcome of patients experiencing pulmonary artery (PA) trauma during balloon dilation (BD). BACKGROUND: Balloon dilation of the PA is important in the management of peripheral pulmonary stenosis. Successful BD requires a controlled tear of the PA; excessive tearing can produce complications ranging from pseudoaneurysms to rupture and death. The incidence and optimum management for such complications are unreported. METHODS: All records of patients who underwent branch PA dilation between June 1984 and October 1997 were reviewed; those with a significant complication were analyzed. RESULTS: Of 1,286 catheterizations in 782 patients, PA trauma (excluding isolated pulmonary edema and PA aneurysms) was identified in 29 catheterizations in 26 patients. Tears occurred distal to the area of stenosis in most cases (62%). Intensive medical management, with and without catheter directed therapy, was employed. The damaged PA was successfully coil embolized in five patients, four of whom survived; temporary balloon occlusion did not prevent death in two patients. There were six deaths from pulmonary hemorrhage. A case control analysis demonstrated that PA trauma was significantly associated with pulmonary hypertension. CONCLUSIONS: Pulmonary artery trauma associated with BD occurs mostly distal to the site of narrowing, is associated with underlying pulmonary hypertension and is frequently (5/12 or 42%) fatal in those with unconfined tears. Intensive management strategies as well as attention to distal balloon position may reduce incidence and mortality. Coil occlusion of the damaged PA appears to be a valuable strategy to prevent fatal hemorrhage.

Early results and medium-term follow-up of stent implantation for mild residual or recurrent aortic coarctation.

BACKGROUND: Optimal timing and mode of treatment for patients with aortic coarctation remains controversial, particularly when the degree of obstruction is mild. Surgery, balloon dilatation, and stent implantation have all proven effective in the treatment of moderate or severe obstruction. In this report, we describe the use of stents to treat coarctation in a heterogeneous population, including patients with relatively mild obstruction. METHODS: Retrospectively, we studied the results of stent implantation in 33 patients, children and young adults, who underwent catheterization for treatment of coarctation. Patients with isolated coarctation, as well as those with associated cardiac defects, were included. The median systolic pressure gradient of our patients was 25 mm Hg. RESULTS: Patients had an acute decrease in systolic blood pressure gradient (25 mm Hg to 5 mm Hg, P <.001) and an increase in lumen diameter (8 mm to 13 mm, P <.001). When 16 patients were recatheterized during the follow-up period, gradients remained decreased (30 mm Hg to 14 mm Hg, P <.001) compared with prestent values. Ventricular end-diastolic pressure, which was increased in 82% of patients at the time of initial catheterization, decreased from 17 mm Hg to 14 mm Hg (P =.002). Although the procedure was generally safe, serious complications did occur. CONCLUSIONS: Stent implantation represents a therapeutic option that can safely and effectively reduce gradient in challenging patients with mild postoperative coarctation. Furthermore, our data suggest that aortic obstruction often coexists with ventricular diastolic dysfunction in these patients and that relief of obstruction may play a role in improvement of function.

Fate of moderate and large secundum type atrial septal defect associated with isolated coarctation in infants.

A moderate to large secundum atrial septal defect associated with isolated coarctation in infancy is likely to close spontaneously. Nine of 12 defects, including 4 defects > or =8 mm in at least 1 dimension, had either closed or were believed to be hemodynamically insignificant at follow-up, supporting the strategy of a lateral thoracotomy approach to coarctation and deferral of atrial surgery.

Spinal fusion in patients with congenital heart disease. Predictors of outcome.

The strong association between congenital heart disease and spinal deformity is well established, but data on the risks and outcome of spinal fusion surgery in patients with congenital heart disease are scarce. The purpose of this study was to identify predictors of perioperative risk and outcome in a large series of children and adolescents with congenital heart disease who underwent spinal fusion for scoliosis or kyphosis. In the authors' retrospective analysis of 74 consecutive patients with congenital heart disease undergoing spinal fusion, there were two deaths (2.7%) and 18 significant complications (24.3%) in the perioperative period. Preoperative cyanosis (arterial oxygen saturation < 90% at rest) with uncorrected or incompletely corrected congenital heart disease was associated with both deaths. Complications occurred in nine of 18 (50%) patients with cyanosis and in 11 of 56 (20%) patients without cyanosis. As judged by multivariate analysis the best predictors of perioperative outcome were the overall physical status of the patient as represented by the American Society of Anesthesiologists' preoperative score and a higher rate of intraoperative blood loss. Seventeen of 43 patients (40%) with an American Society of Anesthesiologists score of 3 or higher experienced complications including two perioperative deaths. Successful spinal fusion and correction were achieved in 97% of patients. Children and adolescents with congenital heart disease can undergo elective spinal fusion with risks that relate to overall cardiac status. Careful assessment of preoperative status by pediatric cardiologists and cardiac anesthesiologists familiar with surgical treatment of patients with congenital heart disease will assist the orthopaedic surgeon in providing the most realistic estimate of risk.

Repeat balloon dilation of congenital valvar aortic stenosis: immediate results and midterm outcome.

While balloon dilation (BD) has become the initial treatment for congenital valvar aortic stenosis (CVAS) at many institutions, repeat BD for recurrent obstruction has been reported only in a few. Between January 1985 and December 1996, 298 patients (70 neonates) underwent BD, 34 of whom underwent a repeat BD without mortality. A greater proportion of neonates had a repeat BD (26% vs. 8%, P < 0.001). At repeat BD (1 day-7.5 years post initial BD), the mean peak-to-peak gradient was reduced from 67+/-24 to 36+/-16 mm Hg (P < 0.0001). Aortic regurgitation (AR) increased immediately in 26%, being moderate or more in 24%. During a mean follow-up of 5.2 years, there was one surgically related death. Of the 33 survivors, 6 had surgery for residual stenosis and/or AR. Among the remaining 27 patients, 96% were asymptomatic, the peak instantaneous aortic valve Doppler gradient was 50+/-15 mm Hg with AR absent in 8%, mild in 62%, and moderate or more in 31%. In conclusion, repeat BD is effective and without mortality. AR was at least moderate in 24% of patients immediately after a second BD. Repeat BD was more common in patients who underwent the initial BD as neonates.

Mitral and aortic atresia associated with hypoplastic right lung, crossover segment of right lower lobe, and anomalous scimitar-like right pulmonary venous connection with inferior vena cava: clinical, angiocardiographic, and autopsy findings in a rare case.

A newborn female infant was found to have a unique and previously unreported group of anomalies: (1) mitral and aortic atresia with a highly obstructive atrial septum; (2) hypoplasia of the right lung with a crossover segment involving the right lower lobe; (3) normally connected pulmonary veins, two from the left lung and one from the right; and (4) a large anomalous branch of the right pulmonary vein of scimitar configuration that anastomosed with the normally connected right pulmonary vein and with the inferior vena cava (IVC). The scimitar vein appeared obstructed at its junction with the right pulmonary vein and at its junction with the inferior vena cava within the hepatic parenchyma. To our knowledge, this is the first report of a scimitar-like vein coexisting with mitral and aortic atresia and connecting both with the right pulmonary vein and with the inferior vena cava. The highly obstructed left atrium was partially decompressed by retrograde blood flow via the normally connected right pulmonary vein to the anomalous scimitar venous pathway and thence to the inferior vena cava via a pulmonary-to-IVC collateral vein.

Development of a double-chambered right ventricle after repair of tetralogy of Fallot.

OBJECTIVES: We sought to determine the frequency, etiology and progressive nature of midcavity obstruction in patients after primary repair of tetralogy of Fallot (TOF). BACKGROUND: Midcavity obstruction (double-chambered right ventricle [DCRV]) represents a significant portion of reoperations in patients who have had TOF repair. This group is still poorly defined. METHODS: A retrospective review of clinical, echocardiographic and catheterization data for all patients with TOF who later underwent reoperation for DCRV was performed. RESULTS: Between 1973 and 1995, 552 children <2 years of age underwent primary TOF repair (median age 6.7 months). Long-term follow-up (median 50 months) was available in 308 children. Of these, 17 children subsequently developed DCRV requiring reoperation. The median age at initial operation was 7.9 months. During a median follow-up interval of 43.2 months, murmur intensity increased in all patients, and the average subpulmonary gradient at catheterization increased from 24+/-10 to 80+/-27 mm Hg in seven children (p = 0.002) and at Doppler echocardiography from 14+/-16 to 89+/-18 mm Hg in five children (p = 0.002). Before reoperation, 6 of the 17 children were symptomatic. During the operation (median age 55.4 months), obstruction was relieved by incision of hypertrophied anomalous muscle bundles in all 17 patients, with prominent fibrosis noted in 8 patients. Excessive septal and parietal hypertrophy was noted in one child. No new transannular patches were required. Recurrent obstruction has reappeared in 3 of these 17 children during follow-up. CONCLUSIONS: DCRV is a medium-term complication of TOF repair in infants, with a minimal incidence of 3.1% (95% CI 1.8% to 4.9%). The condition is progressive and is due to anomalous muscle bundle hypertrophy or fibrosis, or both, which may represent displaced insertion of a moderator band. Further reobstruction does occur; continued careful follow-up is therefore essential.

Percutaneous therapy of structural heart disease: pediatric disease.

Interventional therapy of congenital heart lesions at cardiac catheterization has greatly increased during the past decade. At the authors' institution, the frequency of such procedures among catheterizations has increased from 5% to more than 60%. The variety of lesions so treated continues to expand and equipment continues to improve. These procedures may be divided into 2 groups, namely (1) those involving balloon dilation of stenotic valves and vessel obstructions with stent placement being increasingly used in the latter and (2) those involving occlusion of lesions with (a) coils, such as aortopulmonary collaterals, patent ductus arteriosi and coronary artery fistulae and (b) umbrella devices, such as atrial and ventricular septal defects. These have replaced surgery as the initial procedure of choice in many lesions including valvar pulmonary and aortic stenoses, and postoperative aortic coarctation in young patients. In addition, use of the double-umbrella device even in noncongenital lesions appears promising.

Clinical course and hemodynamic observations after supraannular mitral valve replacement in infants and children.

OBJECTIVES: We report the clinical course and unique hemodynamic findings after placement of a supraannular mitral valve prosthesis. BACKGROUND: Children with symptomatic mitral valve disease whose annulus is too small for the smallest prosthesis are difficult to manage. One option is valve replacement with a prosthesis positioned entirely within the left atrium (LA). METHODS: We reviewed 17 patients (median age 10 months) with symptomatic mitral valve disease who underwent placement of a supraannular valve prosthesis between 1980 and 1994. RESULTS: The actuarial survival rates were 88% at 1 month and 71%, 62% and 53% at 1, 2 and 10 years, respectively. Preoperative hemodynamic data (mean +/- SD)) compared with those after placement of the supraannular mitral prosthesis were as follows: "a" wave to left ventricular end-diastolic pressure gradient 17 +/- 5 versus 4 +/- 4 mm Hg (p = 0.003), mean LA pressure 25 +/- 6 versus 20 +/- 6 mm Hg (p = 0.07), "a" wave 30 +/- 6 versus 19 +/- 5 mm Hg (p = 0.006), "v" wave 28 +/- 5 versus 30 +/- 9 mm Hg (p = 0.31), mean pulmonary artery pressure 54 +/- 19 versus 42 +/- 15 mm Hg (p = 0.07) and left ventricular end-diastolic pressure 14 +/- 5 versus 16 +/- 4 mm Hg (p = 0.12). CONCLUSIONS: Supraannular mitral valve replacement provides relief of mitral stenosis or mitral regurgitation. However, LA to left ventricular early diastolic gradients with large atrial "v" waves contribute to elevated mean LA pressures in the absence of prosthetic valve obstruction or regurgitation. As a result of this unexpected finding, associated left heart obstructive lesions and pulmonary and left ventricular end-diastolic hypertension, the outlook remains poor.

Transvascular balloon dilation for neonatal critical aortic stenosis: early and midterm results.

OBJECTIVES: We evaluated our immediate and midterm (mean 4.3 years) results of balloon dilation of critical valvular aortic stenosis in 33 neonates. BACKGROUND: Balloon dilation has been used as an alternative to surgical treatment. Reports to date consist of small series (largest 16 babies) with short-term follow-up (longest 4.8 years). METHODS: From 1985 to 1991, 33 neonates had dilation at a mean age of 13 days and a mean weight of 3.4 kg. Nineteen of the neonates (58%) were intubated and received prostaglandins, and 94% had other cardiac abnormalities. RESULTS: The dilation was completed retrograde in 31 of the neonates (umbilical artery in 11 and femoral artery in 20) and anterograde (femoral vein) in 2. The average immediate peak gradient and left ventricular end-diastolic pressure reductions were 54% and 20%, respectively. The overall mortality rate was 12% (three early deaths and one late). All 20 neonates dilated through a femoral artery initially had pulse loss with restoration in 35% after thrombolytic therapy. At 8.3 years, survival and freedom of reintervention probability rates were 88% and 64%, respectively. At mean 4.3 years of follow-up, 83% of the survivors were asymptomatic; Doppler study revealed a maximal instantaneous gradient < 50 mm Hg in 65% of neonates and significant aortic regurgitation in 14%. CONCLUSIONS: This study confirms that dilation of aortic stenosis in neonates is effective; reintervention (mostly redilation) is frequent (40%); and midterm survival is encouraging (88%).

Transcatheter fenestration dilation and/or creation in postoperative Fontan patients.

There are very few therapeutic options for severely symptomatic Fontan patients after spontaneous complete or virtual fenestration closure. Its reopening in 14 such patients led to dramatic hemodynamic improvement in most. The clinical experience with transcatheter fenestration creation and/or dilation in symptomatic Fontan patients is reported demonstrating feasibility, safety, and a novel management option for these patients.

Conversion of modified Fontan procedure to lateral atrial tunnel cavopulmonary anastomosis.

After modified Fontan procedures with atriopulmonary anastomoses or right atrium-right ventricle conduits, some patients have progressive exercise intolerance, effusions, arrhythmias, or protein-losing enteropathy. Theoretic advantages of a lateral atrial tunnel cavopulmonary anastomosis and published clinical results suggest that conversion of other Fontan procedures to the lateral atrial tunnel may afford clinical improvement for some patients. Eight patients (8 to 25 years old) with tricuspid atresia (n =4), double-inlet left ventricle (n = 3), and double-outlet right ventricle (n=1) underwent conversion to a lateral tunnel procedure between December 1990 and November 1994. An arbitrary clinical score was assigned before the lateral tunnel procedure and at follow-up. Before conversion, patients had decreased exercise tolerance (n = 8), arrhythmias (n = 6), effusions (n = 4), and protein-losing enteropathy (n = 8). At catheterization, all had a low cardiac index (1.9 +/- 0.7 L x min(-1) x M(-2), five had elevated pulmonary vascular resistance (>3 Wood units), and three had right pulmonary venous return obstruction by compression of an enlarged right atrium. Fenestrated lateral tunnel construction was undertaken 7.3 +/- 3.6 years after atriopulmonary anastomosis, with one early death related to low cardiac output. After the lateral tunnel procedure, two patients had no clinical improvement (no change in clinical score) but five patients had either marked or partial improvement. The right pulmonary vein compression present in three patients was resolved after conversion. The mean clinical scores improved from 4.5 +/- 1 to 3.0 +/- 2 (p < 0.04). In conclusion, conversion to a lateral tunnel procedure led to clinical improvement in five of eight patients at short-term follow-up and may be particularly indicated for patients with giant right atria or pulmonary vein compression who have symptoms. Pulmonary vein compression should be looked for in patients after modified Fontan procedures and can be relieved by conversion to the lateral tunnel procedure.

Midterm results of balloon dilation of congenital aortic stenosis: predictors of success.

OBJECTIVES: We evaluated patient and procedural characteristics that influence the midterm success of balloon dilation of congenital aortic stenosis. BACKGROUND: Balloon dilation is a new treatment for congenital aortic stenosis. Factors that influence midterm success are unknown. METHODS: We performed a retrospective review of 148 children >1 month old who underwent balloon dilation for aortic stenosis. RESULTS: Balloon dilation was successful in 87% of patients, with a procedural mortality rate of 0.7%. The average immediate peak to peak gradient reduction was 56.4 +/- 19.9% (mean +/- SD). Prior valvotomy was the only factor that significantly reduced the immediate gradient reduction after dilation (47.1 +/- 21.8% vs. 57.8 +/- 19.6%, p < 0.01). Survival after dilation was 95% at 8 years. Seventy-five percent of patients were free of repeat intervention 4 years after dilation, whereas 50% remained free of repeat intervention at 8 years. Asymmetrically thick valve leaflets (risk ratio [RR] 0.17, p < 0.01) and prior aortic valvotomy (RR 0.35, p = 0.02) decreased the risk of repeat intervention. Aortic regurgitation grade > or = 3 (RR 4.27, p = 0.04) and residual gradient after dilation (RR 1.63 for 10 mm Hg, p < 0.01) increased the risk. CONCLUSIONS: The 8-year survival rate after dilation was 95% with 50% of patients free of repeat intervention. Factors that increased the risk for repeat intervention included symmetrically thin or thick aortic valve leaflets, regurgitation grade > or = 3 after dilation and a high residual gradient after dilation. The incidence of repeat intervention after dilation was high owing to its palliative nature.

Prolongation of RV-PA conduit life span by percutaneous stent implantation. Intermediate-term results.

BACKGROUND: Right ventricle-to-pulmonary artery (RV-PA) homografts and bioprosthetic conduits are commonly used to palliate various types of complex congenital heart disease. These conduits frequently develop progressive obstruction and require surgical replacement. This report reviews our experience implanting balloon-expandable stents to relieve conduit obstruction and delay reoperation. METHODS AND RESULTS: A retrospective review identified 44 patients who underwent placement of 48 stents in obstructed RV-PA conduits. Median patient age was 6.9 years (range, 7 months to 30 years), and median follow-up time was 14.2 months (range, 0 to 48 months). Stent implantation initially decreased the RV-PA pressure gradient from 61.0 +/- 16.9 to 29.7 +/- 11.9 mm Hg (P < or = .001) and the right ventricular-to-systemic arterial pressure ratio from 0.92 +/- 0.17 to 0.63 +/- 0.20 (P < or = .001). The diameter of the stenotic region expanded from 9.3 +/- 3.5 to 12.3 +/- 3.3 mm in the anteroposterior view (P < or = .001) and from 6.6 +/- 2.9 to 10.9 +/- 2.5 mm in the lateral view (P < or = .001). During the follow-up period, 2 patients had their stents redilated, 7 had additional conduit stents deployed, and 14 underwent surgical replacement of their conduits. Actuarial freedom from conduit reoperation was 65% at 30 months postprocedure. Seven patients were found to have fractured stents on follow-up, suggesting an important role for external compressive forces in conduit failure. Recatheterization in 16 patients a median of 11.8 months (3 to 48 months) postprocedure demonstrated hemodynamic evidence of recurrent obstruction despite sustained enlargement at the previously stented sites. Complications included stent displacement (n = 1), bacterial endocarditis (n = 1), and false aneurysm formation (n = 1). One patient died awaiting conduit replacement surgery. CONCLUSIONS: Stent implantation in obstructed RV-PA conduits results in significant immediate hemodynamic and angiographic improvement. In a subgroup of patients, the procedure prolongs conduit life span by several years and increases the interval between conduit reoperations. Recurrent obstruction is caused by external compression and progressive stenosis outside the stented region.

Orthodeoxia-platypnea due to intracardiac shunting--relief with transcatheter double umbrella closure.

The safety and efficacy of transcatheter clamshell occlusion of patent foramen ovale for relief of severe arterial desaturation and dyspnea in the upright position due to intracardiac shunting were examined in eight patients with excessive risk of surgical patent foramen ovale closure. All patients had successful reduction of intracardiac shunting with an immediate rise in oxygen saturation > or = 95% by implantation of a clamshell device on the atrial septum. Despite two early incidents of device embolization, retrieval and immediate re-implantation, and one patient with nonsustained atrial and ventricular arrhythmias, there were no adverse clinical sequelae. In follow-up evaluation transcatheter clamshell closure of patent foramen ovale has provided persistent relief from shunt-related arterial desaturation and symptomatology in all living patients.

Hepatic venous blood and the development of pulmonary arteriovenous malformations in congenital heart disease.

BACKGROUND: Pulmonary arteriovenous malformations (PAVMs) are a known complication after some types of cavopulmonary anastomoses (CVPAs). Their cause is unknown, but they may be related to the absence of pulsatile flow or the presence or absence of circulating factors. These PAVMs are diffuse and are presumed to be progressive and irreversible. METHODS AND RESULTS: All patients with congenital heart disease (CHD) seen at Children's Hospital, Boston, Mass, between 1970 and 1993 were reviewed. We report on the 10 patients with CHD who were found to have developed PAVMs, as diagnosed by cardiac catheterization. Diagnoses included heterotaxy syndrome/polysplenia, with interrupted inferior vena cava and hepatic veins draining to the right atrium (n = 6); heterotaxy/asplenia (n = 1); corrected transposition with pulmonary stenosis (n = 1); and biliary atresia and associated CHD (n = 2). PAVMs were diagnosed 0.1 to 7.0 years (median, 3.5 years) after creation of a CVPA that resulted in exclusion of hepatic venous flow from one or both lungs in 8 of the 10 patients; the remaining 2 patients had normal drainage of hepatic veins to the lungs but had biliary atresia. In all, the common anatomic feature was the exclusion of normal hepatic venous return from the affected pulmonary arterial circulation. All patients with interrupted inferior vena cava, azygous continuation to the superior vena cava, and hepatic veins draining to the right atrium (polysplenia syndrome) were reviewed to determine the incidence of PAVMs in those with CVPA (ie, hepatic venous flow excluded from the pulmonary arteries) and without CVPA. Six of 28 (21%) of those with versus 1 of 56 (1.8%) of those without CVPA developed PAVMs (P = .004). The 1 patient without CVPA who had PAVMs also had biliary atresia. Among patients with CVPA, the probability of developing PAVMs was 15% and 28% at 3 and 5 years, respectively, after CVPA. The histological and angiographic appearances of PAVMs after CVPA are similar to those seen in PAVMs associated with hepatic cirrhosis. CONCLUSIONS: We postulate that PAVMs after CVPA are related to the diversion of normal hepatic venous flow from the pulmonary circulation. In this sense, these PAVMs may be analogous to those associated with liver disease, which have been found to resolve after liver transplantation. Redirection of hepatic flow to the pulmonary bed in some patients with CHD and PAVMs may lead to reversibility of the PAVMs.