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

Management of complex left ventricular outflow tract obstruction (LVOTO) can be achieved with a Konno or Modified Konno procedure to enlarge the LVOT. We hypothesized that patients who undergo a Modified Konno procedure would have a higher rate of LVOT re-intervention compared to the Konno procedure. Patients who underwent a Konno or Modified Konno procedure for LVOTO at a single tertiary care center between 1990 and 2014 were retrospectively reviewed. The primary outcome was LVOT re-intervention post-discharge from index Konno or Modified Konno procedure. Cox regression and Kaplan-Meier estimates were used for time-to-event analysis of LVOT re-interventions, any unplanned re-interventions, and transplant-free survival. The study included 122 patients: 51 (41.8%) in the Konno group and 71 (58.2%) in the Modified Konno group. Median age at surgery was 8.2 (IQR 3-16) years in the Konno group and 3.9 (IQR 1.5-11) years in the Modified Konno group. Multiple left heart lesions were less prevalent in Modified Konno patients. There were 36 (29.5%) patients with LVOT re-interventions: 8 (16%) in the Konno group and 28 (39.4%) in the Modified Konno group (p = 0.01). Transplant-free survival at five years was 87.2% for the Konno group and 93.5% for the Modified Konno group. A higher rate of LVOT re-intervention was found in the Modified Konno group although the Konno and Modified Konno techniques were applied to different patient populations. This finding suggests that careful preoperative decision-making can direct therapy appropriately and that fundamental diagnosis affects procedure choice.