Septal myectomy with mitral valve surgery in patients after alcohol septal ablation.

Objectives: We studied 16 patients after failed alcohol septal ablation who underwent extended septal myectomy to analyse the results of surgical correction and identify technical pitfalls the surgeons may be confronted by.

Methods: Between October 2017 and March 2019, 16 patients underwent surgical extended septal myectomy with accompanying anomalous secondary chordae resection, papillary muscles mobilization [in 9 (56.3%) patients], and anterior mitral leaflet plication after previously failed alcohol septal ablation. Routine preoperative computed tomography or cardiac magnetic resonance planning and intraoperative transoesophageal echocardiography were performed in each of the studied patients. Major technical features were identified and complemented during septal myectomy of the calcified interventricular septum.

Results: The mean age of the studied patients accounted 50.5 ± 14.6, median-54; males-5 (31.3%). Mean cross-clamp time accounted 52 ± 7.2 min. Calcified basal interventricular septum was identified in 2 (12.5%) patients. No iatrogenic ventricular septal defect (0%) was made during surgical correction. Peak systolic pressure gradient decreased from 86 (interquartile range: 75-104.7) to 20 (16-22) mmHg (P< 0.001). No patients with moderate or severe mitral regurgitation were identified, whereas before the procedure, the number of those accounted 13 (81.2%) individuals. In-hospital and overall mortality after septal myectomy accounted 0%.

Conclusions: Extended septal myectomy in patients who previously underwent alcohol septal ablation is a safe procedure that affects all pathological manifestations of the disease. Routine preoperative computed tomography or cardiac magnetic resonance provides detailed anatomy of the anomalous left ventricle and subvalvular structures and allows to measure the extension of myectomy preventing the occurrence of iatrogenic ventricular septal defect. Septal myectomy of the calcified interventricular septum requires avoidance of 'one-piece technique' since fragmental myectomy allows visually control the adequacy of the left ventricle outflow tract release.