1. Clinical Overview
n-Butyl-2-cyanoacrylate (NBCA) is a liquid embolic agent and tissue adhesive belonging to the cyanoacrylate class. It is a monomer that undergoes rapid anionic polymerization upon contact with ionic substances (e.g., blood, tissue fluids), forming a solid, flexible, and histotoxic polymer that mechanically occludes vessels and adheres to tissues. In the 0.5ml presentation, it is primarily used for the embolization of vascular malformations and as a topical hemostatic/sealant in surgical settings. It is not a systemic drug but a medical device/implant.
| Onset | Duration | Bioavailability |
|---|---|---|
| Immediate (polymerizes within 1-5 seconds upon contact with blood or tissue moisture). | Permanent. The polymer is non-biodegradable and remains as a permanent implant/foreign body, though it may be encapsulated by fibrous tissue over months to years. | Not applicable (N/A). It is a topical/endovascular implant with no systemic absorption when used correctly. |
2. Mechanism of Action
n-Butyl-2-cyanoacrylate is a liquid monomer. Upon contact with anions (e.g., hydroxide ions in water, blood, tissue fluids), it undergoes rapid exothermic anionic polymerization, transforming from a liquid to a solid, flexible polymer. This polymerization creates a mechanical plug that occludes blood vessels (embolization) or seals tissue planes (adhesion). The polymer elicits a significant foreign body inflammatory reaction, leading to fibrosis and permanent vessel/tissue occlusion.
3. Indications & Uses
- Endovascular embolization of cerebral arteriovenous malformations (AVMs).
- Embolization of peripheral arteriovenous malformations (AVMs) and fistulae.
- Pre-operative embolization of hypervascular tumors (e.g., meningiomas, juvenile nasopharyngeal angiofibromas).
4. Dosage & Administration
Adult Dosage: Dose is NOT by body weight. It is volume-based and lesion-specific. For embolization, typically 0.1ml to 0.5ml per injection, often diluted with ethiodized oil (Lipiodol) to ratios from 1:1 to 1:4 (NBCA:Oil) to control polymerization rate. Total volume per procedure varies greatly (may be 1-4ml).
Administration: FOR TRAINED SPECIALISTS ONLY. Use under fluoroscopic/angiographic guidance. Must be prepared in a dedicated procedure room. For embolization: Mix with ethiodized oil in a sterile container immediately before use. Load into dedicated syringes and delivery catheters (e.g., Debrun-type or flow-directed microcatheters). Flush catheter with 5% dextrose solution (non-ionic) before and after injection to prevent premature polymerization. Injection must be a continuous, controlled push under live fluoroscopy. Catheter must be withdrawn immediately after injection to avoid being glued in place.
5. Side Effects
Common side effects may include:
- Transient fever.
- Local pain and tenderness at injection/application site.
- Inflammatory reaction (redness, swelling).
- Nausea/vomiting (post-embolization syndrome).
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Ionic Solutions (Normal Saline, Ringer's Lactate) | Causes immediate, uncontrolled polymerization in catheter or syringe, ruining the procedure and risking catheter entrapment. | High |
| Heparin, Warfarin, DOACs | Increased risk of hemorrhage at vascular access site. Requires careful management of anticoagulation around procedure time. | Moderate |
| Iodinated Contrast Media | Can initiate polymerization if mixed. They are used sequentially, not mixed, during angiography. | High |
7. Patient Counselling
- Do inform your doctor of all allergies, especially to adhesives/glues.
- Do follow all pre-procedure instructions regarding fasting and medications.
- Don't apply any pressure or manipulate the application site after the procedure as advised.
- Do report any signs of infection (fever, increasing pain, redness) immediately.
8. Toxicology & Storage
Overdose: "Overdose" manifests as non-target embolization or excessive glue volume leading to: Tissue infarction (stroke, bowel ischemia, limb ischemia), Pulmonary embolism (dyspnea, chest pain, hypoxia), Catheter entrapment, Excessive inflammatory response/tissue necrosis.
Storage: Store in a cool, dry place. Recommended storage temperature: 2°C to 8°C (refrigerate). Do not freeze. Protect from moisture. Keep vial in its original packaging until use. Shelf life is typically 24-36 months from date of manufacture. Once opened, the vial is for single use only. Any unused portion must be discarded. Contains cyanoacrylate; keep away from skin, eyes, and clothing.