2021 AF Symposium
Live Case: Vein of Marshall Alcohol Ablation
by Steve S. Ryan
Background: In difficult cases of A-Fib (persistent, long-standing persistent), catheter ablation has had limited success. Adding ablation of the Vein of Marshall using Ethanol has been proven effective. In the VENUS clinical trial, the ethanol infusion ablation patients had significantly improved “AF burden, freedom from AF after multiple procedures, and peri-mitral flutter block” versus the ablation-only patients.

Dr. Miguel Valderrabano
Live from Houston
The AF Symposium audience watched on live streaming video as Dr. Miguel Valderrabano of the Methodist DeBakey Heart Center in Houston, Texas, demonstrated an innovative treatment for A-Fib using Alcohol Ablation of the Vein of Marshall.
The Patient: A 69-year-old male had been in persistent A-Fib for 3 years, He had been cardioverted and was on amiodarone. He was mildly symptomatic. He came to Dr. Valderrabano in June 2020 in persistent A-Fib for at least 7 months.
When the Symposium audience first saw Dr. Valderrabano in Houston, he had already performed a standard Pulmonary Vein Isolation (PVI) of the PVs when the patient went into peri-mitral atrial Flutter. He also had worked on the posterior left atrium wall.
The Vein of Marshall

Location of Vein of Marshall
The Vein of Marshall is a vein connected to the Coronary Sinus near its opening (ostium).
In difficult A-Fib cases (persistent, long-term persistent), it can contain A-Fib signals (potentials, triggers) which are hard to reach and ablate. It’s located within the mitral isthmus.
Mapping and Diagnostic Catheter
In this live case, Carto mapping had revealed that this patient’s Vein of Marshall did have A-Fib signals.
Dr. Valderrabano had a sheath in the coronary sinus and a LIMA catheter engaged in the vein of Marshall ostium. (A LIMA catheter can be bent into various shapes.) He advanced a miniaturized octapolar Baylis diagnostic catheter (which specializes in reaching previously inaccessible areas of the heart) into the vein of Marshall.
Innovative Treatment: Ethanol Ablation
Dr. Valderrabano demonstrated an innovative ablation treatment called Ethanol Ablation.
Using a 2 mm balloon catheter containing ethanol, he distributed ethanol into the Vein of Marshall starting distally (at the far end of the vein). He would deflate the balloon and re-inflate it with ethanol to continue the ablation.
He stressed that the Vein of Marshall is somewhat delicate and frail.
He very gently injected the ethanol and did it in stages (distal to proximal), 1 cc over 2 minutes. He was able to achieve peri-mitral atrial flutter block by ethanol to achieve mitral Isthmus ablation. The patient’s Flutter terminated after the first ethanol injection!
He wound up doing 5 injections to cover the entire Vein of Marshall and its branches.
The ethanol basically scars (denervates) the Vein of Marshall eliminating any potentials (A-Fib signal sources or triggers).
He did this in graduated stages to make sure the ethanol didn’t affect the left atrium. He pointed out that this ablation technique done properly is safe.
Editor’s Comments
Ethanol Ablation Difficult to Perform: This is the first time I had seen an Ethanol Ablation. It’s obviously not the easiest procedure to perform.
In the VENUS trial, 30 of 185 patients weren’t able to achieve ethanol ablation, even though the operators and A-Fib centers involved were some of the best in the world.
Ethanol Ablation—Potential Breakthrough Treatment! When you consider how difficult it often is to cure more challenging cases of A-Fib (persistent and long-standing persistent), Ethanol ablation as demonstrated by Dr. Valderrabano is a major breakthrough!
EPs now have a way to ablate previously inaccessible areas of the heart!
All too often before this, some patients with persistent/long-standing persistent A-Fib could not be cured and had to resign themselves to live with A-Fib for the rest of their lives.
Now there is hope for even the most difficult A-Fib cases. We may have reached a beginning stage in A-Fib research where no one has to live permanently in A-Fib!
If you find any errors on this page, email us. Y Last updated: Tuesday, June 8, 2021
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Background: In difficult cases of A-Fib (persistent, long-standing persistent), catheter ablation has had limited success. Adding ablation of the Vein of Marshall using Ethanol has been proven effective. In the VENUS clinical trial, the ethanol infusion ablation patients had significantly improved “AF burden, freedom from AF after multiple procedures, and peri-mitral flutter block” versus the ablation-only patients.
Ethanol Ablation Difficult to Perform: This is the first time I had seen an Ethanol Ablation. It’s obviously not the easiest procedure to perform.



