Management of Complex Left Ventricular Outflow Tract Obstruction: A Comparison of Konno and Modified Konno Techniques

Late Outcomes of Konno-Rastan and Modified Konno for Left Ventricular Outflow Tract Obstruction

BACKGROUND

While early outcomes of the Konno-Rastan and modified Konno procedures are known, long-term outcomes remain undetermined. Our objective was to examine long-term clinical and echocardiographic outcomes.

METHODS

Retrospective review was performed of patients undergoing Konno-Rastan and modified Konno for complex left ventricular outflow tract (LVOT) obstruction from January 1980 to January 2021. The Ross-Konno procedure was excluded due to its often limited ventriculotomy.

RESULTS

A total of 92 patients were identified: 73 Konno-Rastan and 19 modified Konno. The modified Konno group was significantly younger (median [interquartile range, IQR]: 6, [2-12] years vs 16 [9-32] years, P = .001). LVOT obstruction was multilevel (39 of 92 [42.4%]), tunnel subaortic (35 of 92 [38.0%]), or aortic valve stenosis/annular hypoplasia (18 of 92 [19.6%]). Shone syndrome was present in 20 of 92 (21.7%) patients. Operative mortality was 7 of 92 (7.6%); 4 of 86 (4.7%) in elective vs 3 of 6 (50.0%) in urgent cases (P = .005). Median follow-up was 12 (IQR, 5-22) years. Aortic valve/LVOT mean gradient was 13 (IQR, 10-18) mm Hg at 1 year but gradually increased to 25 (IQR, 13-46) mm Hg at 10 years. Ejection fraction remained normal. Freedom from reoperation at 5 and 10 years was 77.2% and 58.4% among Konno-Rastan and 57.7% and 41.7% among modified Konno patients (P = .28), respectively. Overall survival at 5, 10, and 15 years was 82.9%, 76.3%, and 65.5%. Risk factors for mortality included older age, New York Heart Association class III/IV, longer cardiopulmonary bypass time, and multilevel LVOT obstruction.

CONCLUSIONS

While LVOT obstruction is alleviated early, recurrent LVOT obstruction occurs over time after Konno-Rastan and modified Konno procedures. Additionally, despite preserved left ventricular systolic function, late overall survival is poor in this young population.

Innovation in surgical treatment of hypertrophic obstructive cardiomyopathy in children

Hypertrophic cardiomyopathy is the second most common cardiomyopathy affecting children and adolescents and is the main cause of sudden death of young athletes. The natural prognosis of children with severe hypertrophic obstructive cardiomyopathy is not optimistic, and it is not uncommon for children with hypertrophic obstructive cardiomyopathy who do not respond to medication. Surgical treatment is often the only solution. Conventional surgical methods in the past include classic or modified extended Morrow operation, classic or modified Konno operation, and Ross-Konno operation. In recent years, with the development of minimally invasive surgery, various minimally invasive surgical methods have emerged endlessly. Because the incision of minimally invasive cardiac surgery is significantly smaller than that of traditional surgery, it causes less trauma, recovers quickly after surgery, and has the advantage of no difference in surgical effect compared with traditional median sternotomy. Tally endoscopic transmitral myectomy, RTM, minimally right thoracotomy, and other surgical methods have achieved encouraging results in adults and some older children with hypertrophic obstructive cardiomyopathy. The appearance of transapical beating-heart septectomy has brought the treatment of hypertrophic obstructive cardiomyopathy from the era of cardiopulmonary bypass and cardiac arrest to a new era of minimally invasive beating-heart surgery. In the past, there were few articles about the treatment of children with hypertrophic obstructive cardiomyopathy. This article reviewed the new progress and prognosis of surgical treatment of children with hypertrophic obstructive cardiomyopathy at home and abroad.