Ablation Therapy: Definition and Treatment Indications
Ablation is a procedure that destroys abnormal tissue using energy sources to create controlled scar tissue, and it is considered as a treatment option when patients have symptomatic arrhythmias that are refractory to medical therapy or when ablation offers superior outcomes compared to medications. 1
Types of Ablation
- Catheter ablation: Minimally invasive procedure that uses catheters inserted through blood vessels to deliver energy (typically radiofrequency) to specific areas of the heart or other organs 1
- Surgical ablation: Direct operative approach that can be performed during open surgery or minimally invasively 1
- Tumor ablation: Used for treating hepatocellular carcinoma and other tumors when surgery is not feasible 1
Cardiac Arrhythmia Ablation Indications
First-Line Treatment
- Wolff-Parkinson-White syndrome in symptomatic patients 1
- Atrioventricular (AV) node reentry with hemodynamic compromise or when associated with other cardiac conditions like coronary artery disease 1
Second-Line Treatment (After Failed Medical Therapy)
- Supraventricular tachycardias that are symptomatic and refractory to medications 1
- Atrial flutter that is recurrent and symptomatic 1
- Ventricular tachycardia in specific cases:
- Symptomatic ventricular ectopic beats that are drug-resistant and significantly impact quality of life 4
Atrial Fibrillation Ablation
- Indicated for symptomatic, drug-refractory atrial fibrillation 1, 5
- Success rates range from 63-85%, often requiring more than one procedure 1
- Not recommended as first-line therapy for most patients with atrial fibrillation 5
Tumor Ablation Indications
Hepatocellular Carcinoma (HCC)
- Primary indication: Patients not eligible for surgical resection or liver transplantation 1
- Curative potential: For tumors ≤3 cm with appropriate margins 1
- Combination therapy: For tumors 3-5 cm, ablation may be combined with arterially directed therapies 1
- Contraindications: Tumors >5 cm generally require other approaches 1
Ablation Selection Criteria for HCC
- Tumor must be amenable to complete treatment with normal tissue margin 1
- Accessible location for percutaneous, laparoscopic, or open approaches 1
- Caution needed for lesions near bile ducts, stomach, bowel, gallbladder, or diaphragm 1
- Subcapsular tumors carry risk of rupture and seeding 1
Alcohol Septal Ablation for Hypertrophic Cardiomyopathy
- Reserved for severely symptomatic patients with obstructive hypertrophic cardiomyopathy who are refractory to maximal medical therapy 1
- Alternative to surgical myectomy in selected patients, particularly older adults 1
- Not recommended for children 1
- Should be performed only at centers with substantial experience in hypertrophic cardiomyopathy 1
Complications and Risks
Cardiac Ablation
- Serious complications: Occur in approximately 3% of patients undergoing catheter ablation 1
- Procedural mortality: 0.2% for AV node ablation, 0.1% for accessory pathway ablation 1
- Common complications:
Tumor Ablation
- Risk of tumor seeding along needle track (<1% for HCC) 1
- "Heat sink effect" near major vessels can reduce effectiveness 1
- Complications related to proximity to critical structures 1
Important Considerations
- Ablation procedures should be performed by experienced operators at centers with appropriate expertise 1
- Patient selection is critical to maximize benefits and minimize risks 1
- For cardiac arrhythmias, ablation has demonstrated superior outcomes and quality of life improvements compared to long-term medical therapy 1, 5
- Cost-effectiveness analyses suggest that ablation, while initially more expensive, may be less costly over time than long-term medical therapy or surgical interventions 1