Pulmonary stenosis in complicated monochorionic twin pregnancies: prevalence, management and outcome.

OBJECTIVE: To review prevalence, management and prognostic factors of pulmonary stenosis (PS) in monochorionic diamniotic (MCDA) pregnancies complicated by twin-to-twin transfusion syndrome (TTTS). METHODS: Retrospective study over the last 10 years in a single referral center. We reviewed fetal echocardiography data of all MC twin cases with diagnosis of isolated PS. We assessed fetoscopy characteristics of those that underwent laser coagulation. We collected data regarding perinatal outcome, neonatal echocardiography and cardiac management. RESULTS: We found 24 cases of isolated PS among 2091 MCDA pregnancies. Among 1052 complicated MCDA that underwent fetal laser surgery, 22 (2.09%) developed PS of which 20 were diagnosed prenatally. Two cases were diagnosed in uncomplicated MCDA pregnancies (0.2%). Four of 22 (18.18%) cases with TTTS showed in utero regression after laser treatment. Thirteen newborns (65%) required valvular dilatation. Peak systolic velocities in the pulmonary artery trunk (PSV-PA) at diagnosis and the interval between the diagnosis of TTTS and that of PS were significantly different (p < 0.001 and p = 0.05 respectively) between PS requiring cardiac intervention and those who did not. CONCLUSION: An elevated PSV-PA at the time of PS diagnosis and a short time-interval between fetoscopic laser surgery and PS diagnosis are predictive of the need for interventional treatment after birth.

Long-term assessment of right ventricular diastolic filling in patients with pulmonic valve stenosis successfully treated in childhood.

Patients with severe pulmonic stenosis (PS) have right ventricular (RV) diastolic filling abnormalities detectable by tricuspid valve pulsed Doppler examination. To determine if these abnormalities persist long term after successful therapy of PS, 19 patients were examined 8 +/- 3 years after PS therapy. At the time of follow-up Doppler examination, the PS gradient was 15 +/- 8 mm Hg. From the tricuspid valve inflow Doppler study, the following measurements were obtained at peak inspiration: peak velocities at rapid filling (peak E) and during atrial contraction (peak A), ratio of peak E to peak A velocities, RV peak filling rate normalized for stroke volume, deceleration time, the fraction of filling in the first 0.33 of diastole as well as under the E and A waves, and the ratio of E to A area. Data from PS follow-up patients were compared with our previously reported data from 12 age-related control subjects and 14 untreated patients with PS. Patients with PS who were followed up had higher peak E velocity (0.75 +/- 0.14 vs 0.59 +/- 0.21 m/s), lower peak A velocity (0.47 +/- 0.09 vs 0.64 +/- 0.28 m/s), higher E/A velocity ratio (1.65 +/- 0.33 vs 1.11 +/- 0.52), higher 0.33 area fraction (0.52 +/- 0.08 vs 0.34 +/- 0.14), lower A area fraction (0.29 +/- 0.06 vs 0.45 +/- 0.21) and higher E/A area ratio (2.48 +/- 0.82 vs 1.73 +/- 1.05) than PS patients without treatment (p less than 0.03). All Doppler indexes of the patients with PS who were followed up were the same as those of the control subjects except for the peak E velocity that was slightly higher (0.75 +/- 0.14 vs 0.63 +/- 0.11 m/s), the peak A velocity that was slightly higher (0.47 +/- 0.09 vs 0.38 +/- 0.09 m/s) and the E/A area ratio that was slightly lower (2.48 +/- 0.82 vs 3.50 +/- 1.25) (p less than 0.03). Thus, at long-term follow-up, all RV diastolic filling indexes in successfully treated patients with PS improved compared with the untreated patients and approached values found in normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiographic assessment of the size of aortic and pulmonary valve annulus before balloon valvoplasty.

Two dimensional echocardiographic measurements of the size of aortic and pulmonary valve annulus were made in 60 patients before balloon valvoplasty and compared to the angiographic measurements. Aortic valve annulus was measured in 34 patients (26 with valvar aortic stenosis and 8 with discrete subaortic stenosis) in the parasternal long axis or apical 5-chamber views. The pulmonary valve annulus was measured in 26 patients with valvar pulmonary stenosis (PS) in the parasternal short axis view of the right ventricular outflow view. The visualization of the annulus was good in all except 2 patients with valvar PS. Angiographic measurements of the aortic and pulmonary valve annulus were made in aortic root and right ventricular angiograms respectively, taken in both right and left anterior oblique views. There was an excellent correlation between the measurements of the annulus size by the two techniques (r value for pulmonary valve 0.91; for aortic valve 0.96; over all 0.94). Echocardiography can accurately measure valve annulus size and help in choosing balloon dilatation catheter of appropriate size before the valvoplasty procedure.

Continuous wave Doppler assessment of patients subjected to pulmonary balloon valvoplasty.

To evaluate the role of Doppler ultrasound in accurately quantitating patients with valvar pulmonary stenosis, we studied 30 patients (20 patients undergoing balloon pulmonary valvoplasty before and after the procedure, and 10 patients who had previously undergone pulmonary balloon valvoplasty) by Doppler echocardiography and cardiac catheterization. The peak systolic gradient was calculated by the two methods within 24 hours of each other. The maximal velocity of blood flow was obtained by non-imaging, continuous wave Doppler ultrasound examination performed from various parasternal and subcostal positions and the valve gradient was calculated using a modified Bernoulli's equation. Transpulmonary peak systolic gradient calculated by Doppler examination ranged from 9 to 159 mm Hg (mean 54.8 +/- 34.5 mm Hg) and correlated well with values obtained at cardiac catheterization (r = 0.94, P less than 0.001). Thus our study shows that accurate quantification of pulmonary valve stenosis can be reliably undertaken non-invasively utilizing Doppler echocardiography.

Assessment of percutaneous balloon pulmonary and aortic valvuloplasty.

Percutaneous balloon pulmonary or aortic valvuloplasty was performed in 66 consecutive patients with no deaths. The transvalvular pressure gradient was reduced from 85 +/- 35 to 30 +/- 15 mm Hg (p less than 0.01) in 39 patients with congenital pulmonary valve stenosis and from 108 +/- 46 to 32 +/- 16 mm Hg (p less than 0.01) in 27 patients with congenital aortic valve stenosis. Subsequent mild aortic regurgitation occurred in seven patients and moderate regurgitation occurred in one patient. Operative evaluation of seven patients with pulmonary valve stenosis who had additional cardiac anomalies revealed the mechanisms of valve opening to be commissural splitting, cusp tear, or avulsion of the cusp from the anulus. Operative evaluation of two patients with residual high aortic valve gradients revealed minor degrees of commissural splitting. Although further evaluation is required to determine the long-term effects, early evaluation indicates that percutaneous balloon valvuloplasty may be useful in the definitive treatment of isolated pulmonary valve stenosis in some patients and of palliative value in others. The procedure is considered palliative in patients with aortic valve stenosis.