Reduction of the left-ventricular outflow-tract obstruction by aortoventriculoplasty--long-term results of 96 patients.

The aortoventriculoplasty (AVP) is an established surgical procedure for enlargement of different types of congenital and acquired obstruction of the left-ventricular outflow tract (LVOTO), especially with narrowing of the aortic valvular and subvalvular segment. Between 1974 and 1992, 96 patients underwent AVP. There were 32 female and 64 male patients, aged 3 to 32 years (mean 11.2 +/- 2.7 years) at operation. Indications for the procedure were as follows: 1. narrowing of the aortic annulus (19 patients), 2. multi-level stenosis (26 patients), 3. "outgrown"-prosthesis (8 patients), 4. recurrent hypertrophic obstructive cardiomyopathy (HOCM) (5 patients), and 5. subaortic stenosis of different origins (38 patients; out of these 19 patients had a "tunnel-like" stenosis, 7 of them with a "Shone-complex"). Seventy-six patients had previous operations at different levels of the left-ventricular tract. The mean preoperative peak transvalvular gradient was 88 +/- 27 mmHg (range 50-160 mmHg) and could be reduced by AVP to 14 +/- 13 mmHg. The early mortality was 8.3% (8/96). Among the last 58 patients there were no deaths. Three patients underwent subsequent reoperations: one for ascending aortic aneurysm, one for right-ventricular outflow tract obstruction (RVOTO), and one for "outgrown" prosthesis. Three patients required pacemaker implantation for a permanent a-v block, 71 of 96 patients had sinus rhythm postoperatively. The long-term results are similar to those of standard aortic valve replacement in childhood and adolescents. The advantages and disadvantages of the AVP in comparison to the other alternative surgical methods for relief of LVOTO are discussed.