Mikael Laredo1, Diala Khraiche2, Olivier Raisky2, Régis Gaudin2, Fanny Bajolle2, Alice Maltret2, Sylvie Chevret3, Damien Bonnet2, Pascal R Vouhé2. 1. Unité Médico-Chirurgicale de Cardiologie Congénitale et Pédiatrique, Centre de référence des Malformations Cardiaques Congénitales Complexes-M3C, Hôpital Necker Enfants Malades, APHP, Université Paris Descartes, Sorbonne Paris-Cité, Paris, France. Electronic address: mik.laredo@gmail.com. 2. Unité Médico-Chirurgicale de Cardiologie Congénitale et Pédiatrique, Centre de référence des Malformations Cardiaques Congénitales Complexes-M3C, Hôpital Necker Enfants Malades, APHP, Université Paris Descartes, Sorbonne Paris-Cité, Paris, France. 3. Service de Biostatistique et Information Médicale, Hôpital Saint Louis, APHP, Université Paris Diderot, Sorbonne Paris-Cité, Paris, France.
Abstract
OBJECTIVE: Transaortic septal myectomy is the gold standard surgery in obstructive hypertrophic cardiomyopathy, but it is not optimal for children aged less than 5 years and with right ventricular outflow tract obstruction. We evaluated outcomes with the modified Konno procedure in children with severe forms of obstructive hypertrophic cardiomyopathy. METHODS: A total of 79 consecutive children who underwent the modified Konno procedure in our center between 1991 and 2016 were included. RESULTS: Clinical features included age less than 5 years (38%), maximal septal thickness 25 mm or more (32%), extension to the left ventricular apex (29%), and right ventricular outflow tract obstruction (28%). In total, 25% of patients had Noonan syndrome. Five children (6%) aged less than 15 months with Noonan syndrome and biventricular obstruction died in the hospital. Mean follow-up was 6 ± 5.7 years. Survival without death and heart transplantation was 82% at 20 years. Atrioventricular block occurred in 9 patients (11%) and was associated with right ventricular outflow tract obstruction and surgery before 2010. Death, resuscitated sudden cardiac death, and appropriate implantable defibrillator shock were associated with maximal septal thickness before surgery (adjusted odds ratio, 1.20; 95% confidence interval, 1.07-1.35; P = .002) and need for an associated procedure (adjusted odds ratio, 8.84; 95% confidence interval, 2.01-38.93; P = .004). There was no case of recurrent obstruction. Reoperation was required in 4 patients (5%) for other reasons. CONCLUSIONS: The modified Konno procedure provided durable obstruction relief and good long-term survival in children with severe forms of obstructive hypertrophic cardiomyopathy. Children with Noonan syndrome undergoing surgery early in life were at higher risk of early mortality.
OBJECTIVE: Transaortic septal myectomy is the gold standard surgery in obstructive hypertrophic cardiomyopathy, but it is not optimal for children aged less than 5 years and with right ventricular outflow tract obstruction. We evaluated outcomes with the modified Konno procedure in children with severe forms of obstructive hypertrophic cardiomyopathy. METHODS: A total of 79 consecutive children who underwent the modified Konno procedure in our center between 1991 and 2016 were included. RESULTS: Clinical features included age less than 5 years (38%), maximal septal thickness 25 mm or more (32%), extension to the left ventricular apex (29%), and right ventricular outflow tract obstruction (28%). In total, 25% of patients had Noonan syndrome. Five children (6%) aged less than 15 months with Noonan syndrome and biventricular obstruction died in the hospital. Mean follow-up was 6 ± 5.7 years. Survival without death and heart transplantation was 82% at 20 years. Atrioventricular block occurred in 9 patients (11%) and was associated with right ventricular outflow tract obstruction and surgery before 2010. Death, resuscitated sudden cardiac death, and appropriate implantable defibrillator shock were associated with maximal septal thickness before surgery (adjusted odds ratio, 1.20; 95% confidence interval, 1.07-1.35; P = .002) and need for an associated procedure (adjusted odds ratio, 8.84; 95% confidence interval, 2.01-38.93; P = .004). There was no case of recurrent obstruction. Reoperation was required in 4 patients (5%) for other reasons. CONCLUSIONS: The modified Konno procedure provided durable obstruction relief and good long-term survival in children with severe forms of obstructive hypertrophic cardiomyopathy. Children with Noonan syndrome undergoing surgery early in life were at higher risk of early mortality.