Alcohol Septal Ablation (ASA)

ALCOHOL SEPTAL ABLATION (ASA)

Alcohol septal ablation (ASA) is a percutaneous, minimally invasive treatment performed by an interventional cardiologist to relieve symptoms and improve functional status in severely symptomatic patients with hypertrophic cardiomyopathy (HCM) who meet strict clinical, anatomic and physiologic selection criteria. In carefully selected patients, when performed by an experienced interventional cardiologist, the procedure is successful in relieving symptoms in over 90% of patients.

Hypertrophic cardiomyopathy is a condition of the heart muscle which grows abnormally thick, in the absence of a physiologic cause such as hypertension (high blood pressure) or aortic valve disease. In a large subset of patients with hypertrophic obstructive cardiomyopathy, thickening of the heart muscle in a particular part of the interventricular septum causes obstruction to blood being ejected from the left ventricle.

Alcohol septal ablation is a technique designed to reduce the obstruction to blood being ejected from the heart. The technique creates a small controlled heart attack, killing the area of heart muscle responsible for the obstruction, and eventually causing it to become less thick.

ALCOHOL SEPTAL ABLATION

Dr C. O’Mahony/Dr O. Guttmann

Equipment needed:

Barts Angiopack

6F Terumo radial sheath (RRA)

5F femoral sheath (RIJV) - if needs temporary pacing

4F temporary pacing wire

2-0 Silk suture

Tegaderm

6F EBU 3.5 guide catheter

5F JR4 diagnostic catheter

PCI kit

ChoICE floppy wire - straight tip

50mL contrast (PCI balloon solution: 50mL contrast: 50mL saline mixture)

Selection of 1.5 - 2.0 x 10mm OTW balloon

ECHO machine +/- device interrogation

Sonoview contrast

Ultrasound (Sonosite)

Sterile probe cover

Dehydrated alcohol (CD cupboard)

2mL luerlock syringe for delivery

Mild-moderate sedation (Midazolam)

Painkillers (Morphine) and anti-emetic (Metoclopramide)

*patient does NOT need antiplatelet therapy

Outcomes

Relief of obstruction is noted immediately in the majority of appropriately selected patients. Clinical success is defined as a 50% or more reduction in peak gradient across the outflow tract, predicting continued improvement in gradient and cardiac remodeling over the ensuing 1 to 2 years. Over 90% of patients experience a successful procedure, with improvement in outflow tract gradient and mitral regurgitation. Patients typically report progressive reduction in symptoms, including improved shortness of breath, lightheadedness and chest pain. Serial echocardiograms are routinely obtained to follow the cardiac remodeling over time, and document reduction in outflow tract gradient.

When compared to surgical myectomy, similar outcomes are noted out to approximately 10 years. However, a prospective, randomized trial has not been performed. Despite initial concerns regarding long-term arrhythmic potential after alcohol septal ablation, the risk appears to be no worse than for surgical myectomy. It is important to note that patients who fail to respond to alcohol septal ablation may still be candidates for surgical myectomy, and vice versa. Which patients are best served by surgical myectomy, alcohol septal ablation, or medical therapy is an important topic and one which is intensely debated in medical scientific circles.

PROCEDURAL STEPS:

RIJV access for temporary pacing (backup) (5F TPW)

RRA approach (6F)

Insert 5F JR4 diagnostic catheter to shoot RCA

Then 6F EBU 3.5 guidecatheter to engage LMS

Shoot LAD (to size septal branch)

Introduce OTW balloon with ChoICE floppy angioplasty wire

Wire the septal branch

Inflate OTW balloon in the septal branch to isolate it

Inject contrast through central lumen of OTW balloon to visulaize septal branch

Inject Sonoview contrast through central lumen and check using 2D echocardiography

if happy:

give Morphine 5mg, Metoclopramide 10mg, and appropriate sedation (Midazolam) through IV

inject dehydrated alcohol (1.5-2mL) through the central lumen of OTW balloon

shoot septal branch

re-assess hypokinesia using 2D echo

remove all system then closure of RRA using Helix or TR band

end of case