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OBJECTIVE: Transaortic septal myectomy is the gold standard for the treatment of symptomatic hypertrophic obstructive cardiomyopathy refractory to medical therapy. The aim of this study was to assess perioperative outcomes and early clinical results of minimally invasive septal myectomy performed via a small parasternal incision.
METHODS: Between May 2011 and September 2012, 8 patients underwent isolated septal myectomy via a 5 cm right parasternal minithoracotomy. Preoperative and pre-discharge transthoracic echocardiograms (TTE) were obtained for each patient.
RESULTS: Mean age was 56 ± 11 years and six (75%) patients were male. Median preoperative NYHA class was III/IV and three patients (38%) had a previous percutaneous alcohol septal ablation attempt that failed. One patient (13%) had preoperative atrial fibrillation and right bundle branch block. Preoperative TTE evaluation showed the presence of systolic anterior motion of the mitral valve in all patients and median mitral regurgitation grade was 2/4. Mean cardiopulmonary bypass time was 63.8 ± 14.8 minutes and mean aortic cross-clamp time was 53.6 ± 16.2 minutes. There was no intraoperative conversion to sternotomy. Median postoperative length of stay was 5.5 days. There was no in-hospital mortality. Reexploration for bleeding was performed in one patient (13%). Postoperative implantation of a permanent pacemaker was necessary in 3 (38%) patients, including two (25%) who suffered from complete atrioventricular block and one (13%) who suffered from atrial fibrillation and left bundle branch block. Pre-dicharge TTE evaluation showed marked reduction in both septal thickness (21.3 ± 2.8 to 14.9 ± 3.1 mm, p = 0.012) and peak LVOT gradient (71.0 ± 26.6 to 19.7 ± 7.4 mmHg, p = 0.018). Clinical follow-up was available in 6 (75%) patients at a mean follow-up of 3.1 ± 2.6 months. At last follow-up, all patients were alive and in NYHA functional class I.
CONCLUSIONS: This study demonstrates the feasibility of transaortic septal myectomy through a right minithoracotomy. Our early results suggest that this technique is safe and effective. However, further studies with larger cohorts and long term follow-up are warranted.