Ger B.W.E. Bennink

Right ventricular dysfunction and pulmonary valve replacement after correction of tetralogy of fallot

BACKGROUND Correction of tetralogy of Fallot often leads to pulmonary regurgitation, sometimes warranting pulmonary valve replacement, for which indications and timing to achieve optimal results are not yet clear. This retrospective study describes follow-up and reinterventions in our tetralogy of Fallot population. METHODS Review of all consecutive patients operated on for tetralogy of Fallot between 1977 and 2000 was conducted. Included are date and type of repair, Doppler echocardiography (two-dimensional echocardiography), electrocardiographs, reoperations, and physical condition. RESULTS Total repair was performed in 171 patients at a mean age 1.9 +/- 2.5 years, follow-up time counted 9.6 +/- 7.0 years. Right ventriculotomy was used in 92%, and transatrial ventricular septal defect closure was used in 8%; 74% received a transannular outflow patch. Twenty-year survival was 91%. Last follow-up electrocardiographs showed right bundle branch block in 67% and serious arrhythmias in 11%. Two-dimensional echocardiography demonstrated severe pulmonary insufficiency and dilated right ventricle in 31% and 38%, respectively, increasing with postrepair age (p < 0.001). Poor clinical condition (New York Heart Association class II+) and echocardiographic proof of right atrial dilatation (p = 0.012) and arrhythmias (p = 0.03) were significantly associated. Furthermore, the influence of residual hemodynamic lesions, such as a remaining ventricular septal defect or pulmonary stenosis, or right ventricular dilatation was important (p = 0.04). Reintervention was necessary in 32 patients (19%; 10-year freedom, 83%), including angioplasty for residual stenosis and pulmonary valve replacement. At a mean age of 9.2 years after correction, 14 patients received a homograft, and 2 patients received a heterograft. In 7 patients the right ventricle returned to normal dimensions and symptoms disappeared. The incidence of right ventricular dilatation was considerably higher (p = 0.020) in patients with a transannular patch; the transatrial approach showed the opposite (p = 0.03), and patients presented with lower QRS duration (p = 0.007), although no difference could be found between survival after both surgical techniques. Effects of early timing (correction < 6 months) on right ventricular dysfunction could not be established. CONCLUSIONS Severe right ventricular dilatation and pulmonary regurgitation secondary to outflow tract repair in tetralogy of Fallot are frequently occurring sequelae developing slowly over time. Indications for pulmonary valve replacement remain controversial because echocardiographic findings or arrhythmias are not always accompanied by deterioration of clinical condition. However, right atrial dilatation and additional hemodynamic lesions demand increased vigilance. Transatrial repair is associated with a favorable outcome.

Fate of the aortic root after arterial switch operation

OBJECTIVE Concerns have been voiced about possible dilation and insufficiency of the neo-aortic valve after the arterial switch operation (ASO). AIMS To determine growth of the neo-aortic valve and the aortic anastomosis after ASO and the prevalence of insufficiency or stenosis. PATIENTS AND METHODS Since 1977, 144 consecutive patients (pts) underwent ASO for transposition of the great arteries (TGA). Median follow-up was 8.65 years (0.1--22.5 years). Simple TGA was present in 97 pts and 47 had TGA with ventricular septal defect (VSD). Detailed echocardiography included measurements of aortic diameter at four levels. The 608 measurements were compared with published normal values. RESULTS The mean aortic valve z-score was 1.5, without significant change with age (P=0.75). Under 4 months, mean valve z-score was 0.63+/-2.20, between 5 and 12 months 2.56+/-2.30 (P<0.0001). Gradual growth occurs thereafter. The aortic sinus follows an identical growth pattern. The aorta at the anastomosis, is initially smaller than normal (z-score -0.64). After 4 months the z-score is 0.83, followed by continued growth of 0.1 z-score per year. At the last visit, the aortic valve z-score was above 2 in 51 patients, between -2 and 2 in 72 and less than -2 in six patients, none of whom had a flow velocity above 2 m/s. z-score of patients with VSD remained above those without VSD (P<0.0001). Aortic insufficiency was grade 2/4 in three patients, grade 3/4 in one and grade 4/4 in one. No patient developed aortic stenosis. CONCLUSION After ASO the neo-aortic valve and sinus are larger than normal, representing the natural size difference in the prenatal situation and influence of associated cardiac malformations. In the first year of life, rapid dilatation of the new aorta is observed, followed by growth towards normalization of the valve and sinus size. Stenosis at the anastomosis was not observed. Aortic dilatation by itself is rarely associated with significant insufficiency.

Comparative long-term results of surgery versus balloon valvuloplasty for pulmonary valve stenosis in infants and children.

BACKGROUND We compared the long-term results of surgical valvotomy (S) versus balloon valvuloplasty (BV) for pulmonary valve stenosis in infants and children. METHODS Results after surgical pulmonary valvotomy (with concomitant ASD/VSD closure) (n = 62, age 2.9 +/- 3.5 years) and balloon valvuloplasty (n = 108, age 3.6 +/- 3.9 years) were analyzed. Transvalvular mean pressure gradient decrease, freedom from reintervention for restenosis, pulmonary valve insufficiency, and tricuspid valve insufficiency were considered. RESULTS Mean pressure gradient decreased significantly more in the surgical group (from 64.8 +/- 30.8 mm Hg to 12.8 +/- 9.8 mm Hg at a mean follow-up of 9.8 years) than after BV (decreasing from 66.2 +/- 21.4 mm Hg to 21.5 +/- 15.9 mm Hg after a mean of 5.4 years; p < 0.001). Moderate pulmonary valve insufficiency occurred in 44% after surgery, and in 11% after BV (p < 0.001). Tricuspid valve insufficiency occurred in 2% after surgery, and in 5% after BV. Restenosis occurred in 3 surgical patients (5.6%), 2 patients required reoperation, and 1 patient required a balloon valvotomy. Restenosis developed in 13 BV patients (14.1%): 6 patients were redilated and 7 patients required surgery. Surgical valvotomy led to significantly less reinterventions than balloon valvuloplasty (p < 0.04). CONCLUSIONS Surgical relief of pulmonary valve stenosis produces lower long-term gradients and results in longer freedom from reintervention. Balloon valvuloplasty may remain, despite these results, the preferred therapy for isolated pulmonary valve stenosis, because it is less invasive, less expensive, and requires a shorter hospital stay. Surgery should remain the exclusive form of therapy in the presence of concomitant intracardiac defects, which need to be addressed.

Influence of coronary anatomy and reimplantation on the long-term outcome of the arterial switch

BACKGROUND Abnormal coronary artery anatomy is reported to have a significant influence on the outcome of the arterial switch operation. This study examines the impact of coronary anatomy and the occurrence of late coronary obstruction on left ventricular (LV) function and long-term outcome. METHODS Coronary artery anatomy, of 170 patients after arterial switch operation (1977-1999), was determined based on operative reports and pre-operative aortograms. Current status was evaluated using ECGs, echocardiograms, scintigraphy, and post-operative coronary angiograms. RESULTS In 133/170 patients, coronary artery anatomy consisted of an anterior descending (LAD) and circumflex artery (Cx) from the left sinus and the right coronary artery (RCA) from the right or posterior sinus. The left coronary had an intramural initial course in two of these patients. Fifteen patients had the LAD from the left and Cx and RCA from the right sinus; eight had LAD and RCA from one sinus and Cx from the other; four had single ostium; and three had three separate ostia. Four patients had complex patterns and four patients had a supra commissural coronary. To date, follow-up angiography was performed in 59 patients. Surgical coronary sequellae were found in five patients. Two patients had an occluded left ostium. Initially, they were asymptomatic but showed polymorphic ventricular extrasystoles on ECG and moderate LV dysfunction with large irreversible perfusion defects on scintigraphy. Both patients developed ventricular fibrillation at the age of 14 years. One patient did not survive. The other patient required implantation of a defibrillator. One patient has an occluded RCA, one patient has stenosis of the right ostium and one patient has multiple tortuous collaterals without obstruction of a major branch. In the latter three patients, coronary sequellae were not suspected on ECG, echo, or scintigraphy and were only found on follow-up angiography. Retrograde collateral flow was noted in all three occluded coronaries. LV dysfunction, with normal coronaries, was noted in three patients. All, of these patients, had peri-operative ischaemia suggesting failure of myocardial protection. Two are now asymptomatic with mild LV dysfunction. One patient continues to have severe myocardial dysfunction and secondary aortic insufficiency. A Ross-like procedure was performed placing the original aortic valve in the neo-aortic root. Coronary artery anatomy did not influence early survival or late coronary sequellae. CONCLUSION Abnormal coronary anatomy was not a determinant of outcome in our study. Surgical coronary obstruction is independent of original anatomy. It can be almost silent and is potentially fatal. Follow-up angiography must be considered in all patients after the arterial switch operation.

Complication of intra-aortic balloon pumping in a pediatric patient.

A serious complication was seen following insertion of an intra-aortic balloon pump in the ascending aorta in a pediatric patient. The catheter initially coursed to the left subclavian artery from which it folded upon before finding its way in the descending aorta. We recommend that a suitably curved J-tip guidewire be used to guide the IABP balloons distal to the aortic arch into the descending aorta, so as to avoid potentially fatal complications.

Systemic plasma vascular endothelial growth factor levels as a marker for increased angiogenesis during the single ventricle surgical pathway

Cyanosis and the cavopulmonary anastomosis (CPA) are associated with pulmonary arterio-venous malformations (PAVMs) in single ventricle physiology. Vascular endothelial growth factor (VEGF) may be a marker of abnormal angiogenesis in this setting. Plasma VEGF levels were measured in 14 patients undergoing the surgical pathway leading to total cavopulmonary connection (TCPC). Venous blood samples were taken before and then months after CPA (n=6), and immediately before TCPC and 1 month thereafter (n=9). Corresponding arterial saturations were correlated with VEGF levels at each time frame. In six patients, pre-CPA plasma VEGF levels rose from a mean of 24.4-112.4 pg/ml (p<0.03) just prior to completion of TCPC. In nine patients, VEGF levels diminished from 115.7 to 48.9 pg/ml (p<0.05) after TCPC. VEGF levels were disproportionately elevated to arterial saturations most notably after CPA (r2=0.002), suggesting an additional angiogenic stimulus besides cyanosis. Plasma VEGF levels fluctuate during the single ventricle surgical pathway, with maximal levels after CPA, and regression after completion of TCPC. High VEGF levels are disproportionate to hypoxia after CPA, potentially incriminating the absence of hepatic flow to the lungs as an abnormal angiogenic stimulus. Measuring VEGF in venous blood may serve as a biochemical marker of angiogenesis after CPA.

Congenital anomaly of the right coronary leaflet complicated by infective endocarditis

A congenital defect of the right coronary leaflet (fenestration) is an unusually rare cause for aortic incompetence in childhood. We report an eight-year-old child with such an anomaly who presented with infective endocarditis of the left ventricle. The importance of excision of the vegetation prior to the occurrence of life-threatening embolic complications is discussed.