Surgical myectomy

Subvalvular myectomy has a reported success of more than 90% with a mortality rate of less than 2%, but this therapy is not applicable to every patient. Transcatheter ablation of septal hypertrophy has been performed since 1994 as a reasonable option for obstructive HCM patients. An increasing number of reports claim efficacy comparable to that of the surgical approach (3). 

Surgical myectomy involves incision into and resection of small portions of the hypertrophied septum resulting in a significant reduction or abolition of intramyocardial gradients and reduction in mitral incompetence. Patients report a significant reduction in disabling symptoms and improvement in exercise capacity, and the benefit is usually sustained, The complications are few and the postoperative mortality is... 

Patients who have not obtained a satisfactory result after surgical myectomy may also be candidates for septal ablation. Selected patients with advanced function class II with obstructive symptoms that interfere with their occupation may also be candidates for intervention. 

TSable 2 Summary of studies comparing surgical myectomy and septal ablation... 

Table 4 Reported complication after surgical myectomy or septal ablation...

Septal ablation related mortality at experienced centers is currently 1% to 2%, similar to that of surgical myectomy (Table 4). Conduction system abnormalities are relatively common complications of septal ablation, Permanent right bundle branch block occurs in about 50% of patients and transitory complete heart block in 60% and permanent pacemakers required for high grade atrioventricular block in about 5% to 20%, Concerns of late occurrence of complete heart block following septal ablation mandates in-patient monitoring for 4 to 5 days,... 

Ommen SR, Maron BJ, Olivotto I, et al. Long-term effects of surgical septal myectomy on survival in patients with obstructive hypertrophic cardiomyopathy. J Am Coll Cardiol 2005 46 470-476. 

Nagueh Sp Ommen SR, Lakkis NM, et al. Comparison of ethanol septal reduction therapy with surgical myectomy for the treatment of hypertrophic obstructive cardiomyopathy. J Am Coll Cardiol 2001 38 1701 -1706. 

Talreja DR, Nishimura RA, Edwards WD, et al. Alcohol septal ablation versus surgical septal myectomy comparison of effects on atrioventricular conduction tissue, J Am Coll Cardiol 2004 44 2329-2332. 

For patients with a significant obstruction to LV outflow who do not respond to medical management, a surgical approach may be necessary. Septal myectomy and alcohol ablation have been employed. These approaches generally are reserved for patients who have an outflow gradient of more than 50 mm Hg and/or severe symptoms and who have failed an adequate trial of medical therapy. 

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