Angiocardiography in congenital subvalvular aortic stenosis: prognosis and operative indications

Immediate and follow-up results of transluminal balloon dilation for discrete subaortic stenosis

This study presents the findings in 33 patients with discrete subaortic stenosis who were treated by percutaneous balloon dilation and were followed up for 2 months to 6.2 years (mean 34 +/- 21 months). The mean age was 13 +/- 11 years; 10 (30%) were female and 23 (70%) male. Associated malformations were observed in nine patients (27%). All patients underwent noninvasive studies and cardiac catheterization. The mean value to membrane distance was 4.5 +/- 2 mm/m2. After balloon dilation, the pressure gradient from the left ventricle to the aorta decreased from 68 +/- 30 to 20 +/- 13 mm Hg (p less than 0.00001); there were no significant changes in the degree of aortic regurgitation. A fluttering and widely mobile remaining membrane was clearly visualized after dilation. Better immediate results were obtained in patients with a smaller baseline gradient, a larger aortic anulus and a longer valve to membrane distance. Serial follow-up echographic studies were available in 30 patients, and 18 hemodynamic reevaluations were performed in 13 patients. However, seven patients who demonstrated restenosis underwent redilation at a mean of 29 +/- 17 months after the first dilation. Redilation in six of the seven patients obtained benefits similar to those observed at the first dilation. Only one patient with unsuccessful redilation required surgery. The mean value of the last explored residual gradient (on hemodynamic or Doppler study) in the remaining 32 patients was 21 +/- 10 mm Hg. No significant changes were observed in the angiographic evolution of aortic regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic regurgitation after surgical relief of subvalvular membranous stenosis. A long-term follow-up study

A postoperative follow-up study of 21 cases of discrete membranous subvalvular aortic stenosis is presented. The age at operation was 6-47 (mean 16) years, and the follow-up time 0.6-16 (mean 6.7) years. Preoperatively most patients were in NYHA function class II or III and had high peak systolic pressure gradient, left ventricular hypertrophy and/or cardiothoracic index greater than 0.50. At follow-up all but six patients were in NYHA class I, the Doppler-estimated peak systolic gradient was 0-36 (mean 18) mmHg, the cardiothoracic index unchanged and the mean left ventricular hypertrophy score had declined from 4.3 to 2.3. Of 13 patients without aortic regurgitation preoperatively, eight had regurgitation at follow-up (group I) and five did not (group II). The interval to follow-up was significantly longer and the preoperative peak systolic gradient was greater in group I than in group II. Aortic regurgitation may develop even after surgical relief of discrete membranous subvalvular aortic stenosis, possibly associated with high preoperative pressure gradient and time from operation. Regular postoperative Doppler echocardiography is therefore recommended.

Reoperation in congenital aortic stenosis

Over a 22-year period, 81 patients underwent initial operations for critical aortic stenosis at our institution. Their ages ranged from 3 days to 20 years (mean, 7.3 +/- 5.9 years). Fourteen (17%) were infants less than 1 year old. Three children died perioperatively (3.7%). We have followed the survivors and 3 children who underwent initial operations elsewhere for a mean of 9.0 +/- 6.8 years (range, 2 to 23 years). To the present, 27 patients have undergone one reoperation (24 of our initial survivors) at a mean interval of 7.3 years, with 2 perioperative deaths. Ten of these patients have required a second reoperation at a mean interval of 3.7 years, with 2 deaths perioperatively. There were 3 late cardiac deaths after the initial procedure and 1 after a third operation. Actuarial reoperation-free survival is 56.7% at 10 years. While overall survival is 88.6% at 10 years, we find a significantly poorer survival among those patients with valvular stenosis compared with those with subvalvular lesions (p = 0.03). We believe that for children with all levels of aortic stenosis, good functional results and survival can best be obtained by follow-up, recatheterization, and reoperation.

Surgery for discrete subvalvular aortic stenosis: actuarial survival, hemodynamic results, and acquired aortic regurgitation

Discrete membranous subaortic stenosis (DMSS) accounts for 8 to 30% of congenital left ventricular outflow obstruction. The immediate effectiveness of surgical resection of this discrete obstructing membrane has been well documented, but little has appeared regarding late clinical and hemodynamic follow-up. Fifty-three patients with DMSS underwent operation at our institution from 1957 to 1983. Most (78%) were symptomatic, 79% had left ventricular hypertrophy (LVH) by electrocardiogram, and 92% had roentgenographic evidence of cardiomegaly preoperatively. Catheterization revealed a mean preoperative left ventricular-aortic gradient of 89 mm Hg. Twenty-eight patients had associated aortic insufficiency (AI) on the initial aortogram. Seven patients acquired AI in the interim between the first and second preoperative catheterization. Our patients have been followed for up to 12 years postoperatively. There have been 2 early and 3 late deaths. (Actuarial analysis revealed 5- and 10-year survival of 95% and 83%, respectively.) Seventy-one percent of the previously symptomatic patients noted relief of their preoperative complaints, and 45% of those with LVH had a regression in voltage. Cardiomegaly as determined by chest roentgenogram decreased in 45%. The left ventricular-aortic gradient fell to an average of 35 mm Hg a year postoperatively. Surgical treatment of congenital subvalvular aortic stenosis is effective in reducing the preoperative symptoms and the left ventricular-aortic gradient. It appears that DMSS causes AI.

Fixed subaortic stenosis in the young: medical and surgical course in 83 patients

Eighty-three patients aged 11 months to 25 years were followed up a median of 6.1 years (range 8 days to 24 years) after diagnosis of fixed subaortic stenosis (SAS). Fourteen (17%) had significant noncardiac defects and 47 (57%) had additional cardiac malformations. The left ventricular (LV) outflow gradient increased in 25 of 26 patients catheterized more than once before surgery. Of 15 patients less than 12 years old with gradients less than or equal to 40 mm Hg, 10 ultimately underwent operation after developing severe obstruction; another has progressed to a gradient of 45 mm Hg at 6 years of age. Before surgery (at a median age of 12 years), 55% had aortic regurgitation (AR), which was usually mild. Infective endocarditis occurred in 12% of the group, with a frequency of 14.3 cases per 1,000 patient-years. Seventy-four patients were operated on, with 6 early (8%) and 7 late (9%) deaths. Twelve underwent reoperation to relieve residual obstruction. Surgery reduced gradients in patients with discrete SAS from 83 +/- 33 to 29 +/- 30 mm Hg, but in 6 patients with tunnel SAS the reduction was less satisfactory. AR was absent or mild in most patients postoperatively. When the gradient was reduced to less than 80 mm Hg, infective endocarditis did not occur unless there were other residual lesions. These data suggest that it is reasonable to resect discrete SAS in children less than 10 to 12 years old with LV outflow gradients greater than or equal to 30 mm Hg.