Twenty-Year Experience with the Konno Operation: A Definitive Option for Multilevel Left Ventricular Outflow Tract Obstruction

Objectives: Patients with congenital multilevel left ventricular outflow tract obstruction (LVOTO) often have undergone multiple prior interventions. A Konno operation may be applied to avoid further operations in these patients. We reviewed our 20-year experience with the Konno operation to provide insights on patients´ outcomes in the current era.

Methods: Twenty-one consecutive patients underwent the Konno operation between 1996 and 2015. In all cases, the aortic subvalvular region was enlarged with a patch and the aortic valve was replaced with a mechanical prosthesis.

Results: The median age at operation was 12 years [5 months to 34 years]. Eighteen patients had undergone 48 procedures for left-sided heart lesions in 34 previous operations. These procedures included resection of subaortic stenosis (n = 15), aortic valvuloplasty (n = 7), aortic valve replacement (n = 2), mitral valvuloplasty (n = 5), mitral valve replacement (MVR, n = 9), and repair of aortic obstruction (n = 10), respectively. Mitral valve disease was present in 18 patients (stenosis, n = 8; regurgitation, n = 3; prosthesis, n = 7). Prior to the Konno operation, the mean aortic valve gradient was 47 ± 26 mm Hg. The median size of implanted valve prostheses upon the Konno operation was 21 mm [16 to 25 mm]. Concomitant procedures for left-sided heart lesions were enlargement of the ascending aorta (n = 3), MVR (n = 2), and patch plasty for a sinus of Valsalva aneurysm (n = 1). In addition, 2 patients required a MVR during the same hospital admission. There were 2 early deaths (9.5%), one from fatal arrhythmia after subsequent MVR and one from low cardiac output in a patient with preoperative left ventricular dysfunction and mitral regurgitation. During a mean follow-up time of 7.4 ± 5.0 years, there were 3 late deaths (14%), including 2 patients with a mitral prosthesis. Overall survival was 85 ± 7.9% at 1 and 5 years, respectively and 72 ± 11% at 10 years. There was one late reoperation for MVR. Freedom from reoperation after hospital discharge was 94 ± 6.1% at 10 years. The mean aortic valve gradient remained at 15 ± 8.3 mm Hg at a mean follow-up time of 6.6 ± 4.5 years.

Conclusion: The Konno operation relieves multilevel LVOTO with a low probability of reoperation. Mitral involvement is common in these patients and the only cause of reoperation. The Konno operation is a valid option for patients with a multitude of previous operations in whom a definitive repair is essential.