Septal MyectomyEdit

Septal myectomy is a surgical treatment designed to relieve heart outflow obstruction caused by hypertrophic obstructive cardiomyopathy. By removing a portion of the thickened basal interventricular septum, the procedure widens the left ventricular outflow tract (LVOT) and reduces the obstruction that contributes to symptoms such as shortness of breath, chest pain, and fainting. The operation is most commonly performed through a transaortic approach and is often referred to in its classic form as the Morrow procedure. It is typically considered for patients with persistent LVOT obstruction and significant symptoms after optimization of medical therapy, and it is most successful in centers with substantial experience in complex heart surgery. For many patients, septal myectomy offers durable relief and a meaningful improvement in quality of life.

The procedure sits within the broader management of hypertrophic obstructive cardiomyopathy (hypertrophic obstructive cardiomyopathy). HOCM is characterized by thickening of the heart muscle, particularly in the interventricular septum, which can impede blood flow from the left ventricle. In many patients, the obstruction is caused by a combination of septal thickening and systolic anterior motion (SAM) of the mitral valve, which exacerbates the gradient across the LVOT. Septal myectomy directly addresses the anatomical bottleneck in the LVOT, with the goal of producing a lasting reduction in the outflow gradient and, consequently, an improvement in symptoms and functional capacity. For context, the operation is part of a spectrum of interventions that includes less invasive options such as Alcohol septal ablation and optimized medical therapy (e.g., beta-blockers and calcium channel blockers).

Overview

Definition and pathophysiology

Septal myectomy is a surgical resection of a portion of the basal interventricular septum to relieve LVOT obstruction in HOCM. It aims to widen the LVOT and reduce SAM-related turbulence.
The procedure is most effective when the LVOT gradient is driven by septal hypertrophy and SAM, rather than other, more diffuse forms of obstruction.

Techniques

The classic approach is a transaortic septal myectomy, often called the Morrow procedure. In this operation, the surgeon opens the aorta, exposes the basal septum, and carefully resects a portion of the septum to enlarge the outflow tract.
Variants exist, including extended or deeper resections in selected patients, designed to address extensive septal hypertrophy or to optimize the LVOT configuration. Surgeons may tailor the extent of resection to the patient’s anatomy and intraoperative measurements.
The operation is a major cardiothoracic procedure and is performed with cardiopulmonary bypass in experienced centers.

Indications and patient selection

Indicated for patients with symptomatic LVOT obstruction due to HOCM who have not achieved adequate relief with optimized medical therapy.
Preoperative assessment typically includes measurements of LVOT gradients, imaging of septal anatomy, and consideration of concomitant cardiac conditions.
Although age and comorbidity influence risk, septal myectomy in high-volume centers has demonstrated favorable outcomes across a range of ages when carefully selected.

Alternatives and comparisons

Alcohol septal ablation (ASA) is a catheter-based alternative that reduces septal thickness by inducing a controlled infarction in a portion of the septum. It can be an option for patients who are not good surgical candidates, but it may carry different risks and durability profiles compared with surgical myectomy.
Ongoing medical therapy, including beta-blockers or non-dihydropyridine calcium channel blockers, remains a foundational approach for many patients, particularly those with milder obstruction or higher surgical risk.
Decisions about treatment strategy weigh factors such as symptom severity, gradient magnitude, anatomy, patient preference, and local expertise.

Techniques and outcomes

Perioperative considerations

Septal myectomy is most reliably performed in centers with substantial experience in complex heart surgery and in teams that regularly manage HOCM.
Outcomes are closely linked to surgeon experience, institutional volume, and multidisciplinary care. In skilled programs, the procedure has been associated with low perioperative mortality and meaningful long-term symptom relief.
Potential complications include conduction disturbances requiring pacemaker implantation, residual obstruction in some patients, and typical risks of major cardiac surgery such as infection or bleeding, all of which are mitigated by experience and careful patient selection.

Long-term results

The majority of patients experience sustained improvement in functional status and quality of life after septal myectomy, with substantial reductions in LVOT gradients.
Long-term survival after septal myectomy approaches expected survival for matched populations in many reports from high-volume centers.
Durability of the procedure is generally favorable, though ongoing follow-up is important to monitor for recurrent or persistent obstruction and to manage associated conditions.

Controversies and debates

Surgical myectomy versus less invasive therapies

A central debate concerns when to pursue surgical myectomy versus alternatives such as Alcohol septal ablation or continued medical management. Proponents of surgical myectomy emphasize durable gradient relief, lower likelihood of requiring additional interventions, and well-established long-term outcomes in experienced hands. Advocates for ASA stress shorter initial recovery and the possibility of avoiding open-heart surgery, particularly for patients who are not ideal surgical candidates.
From a policy and access perspective, supporters of centralized, high-volume surgical centers argue that outcomes improve with specialization. Critics worry about patient access, wait times, and regional disparities in availability of experienced programs.

Center volume and access

The consensus in many medical communities is that outcomes improve with high-volume centers that treat HOCM regularly. This raises questions about how to balance patient access with the best possible results. Reasonable policies tend to favor referral pathways that connect patients to experienced teams while maintaining reasonable options for those with barriers to access.

Risk–benefit calculus and patient autonomy

While the goal is to maximize symptom relief and long-term prognosis, decisions must consider individual risk profiles, anatomy, and patient preferences. Some critics argue for broader adoption of less invasive options and more personalized decision-making, whereas others contend that, for appropriate patients, the surgical route provides superior durability.