**12. Outcomes**

#### **12.1 Surgical outcomes in adults**

In a report form Mayo Clinic, the risk of hospital death after isolated septal myectomy for obstructive HCM is less than 1%. Reported complications after septal myectomy such as need for permanent pacemaker secondary to complete heart block, and iatrogenic ventricular septal defect occur in about 2% of patients and are considered uncommon. Approximately 90% of patients reported significant improvement in their symptoms after extended left ventricular septal myectomy. Late survival after myectomy has been also reported to be equivalent to an age-matched population and the risk of ICD discharges decreased significantly with elimination of the LVOT obstruction [27].

The transapical approach has been reported in 113 patients with apical HCM. Early mortality was 4% and at late follow-up, 76% of these patients reported improvement in their symptoms. Three patients (3%) underwent heart transplantation due to recurrent heart failure. Survival of this group was superior in comparison to those waiting for heart transplantation [28].

#### **12.2 Surgical outcomes in children**

Children with HCM can present in a similar fashion to adults, with a wide variety of presentations. These symptoms are mostly related to a combination of diastolic dysfunction and significant mitral regurgitation. Sudden death as an initial presentation is more common in children compared to adults [29].

The operation is technically more challenging in children compared to adults due to the obvious anatomic barriers secondary to the small aortic annulus and LVOT. A report from Mayo Clinic included 127 patients who underwent septal myectomy with age ranging from 2 months to 21 years old. There was no early mortality, and the most common concomitant procedures were resection of accessory papillary muscles, mitral valve repair, and closure of an atrial level shunt. Complications included two patients with iatrogenic injury to the mitral valve and seven with aortic valve injury and all were repaired. One iatrogenic ventricular septal defect occurred. There were four late death but the remaining patients reported improvement of their symptoms with 96% being in NYHA class I or II. Repeat septal myectomy was needed in six patients [30].

#### **12.3 Septal myectomy versus alcohol septal ablation**

ASA as mentioned previously has emerged as an alternative to surgical septal myectomy. It can decrease the gradient in the LVOT and improve symptoms, however several studies confirmed the better long-term symptom relief by surgical septal myectomy.

### *Hypertrophic Cardiomyopathy: Surgical Perspectives DOI: http://dx.doi.org/10.5772/intechopen.109568*

The success rate for septal myectomy is higher and the complication rate is lower when it is performed with experienced hands. In a report of 138 patients who underwent ASA, mortality and morbidity were higher than that of age- and gender-matched population who underwent septal myectomy [31]. Survival with septal myectomy is also better in those 65 years of age or younger, in addition to the immediate relief of LVOT gradient and symptoms that is provided by proper septal myectomy.

As mentioned earlier patient selection is a key for either procedure and important to be aware with the risks inherent in those who will undergo septal myectomy after ASA prior to committing them to ASA.
