1. Clinical Overview
n-Butyl-2-cyanoacrylate is a liquid surgical adhesive belonging to the cyanoacrylate class of tissue glues. It is a sterile, low-viscosity, synthetic monomer that polymerizes rapidly upon contact with moisture (e.g., blood, tissue fluids) to form a strong, flexible film, creating an immediate mechanical seal. In the Indian clinical context, it is primarily used as an adjunct to sutures/staples for topical skin closure and for the embolization of vascular malformations. It is not a systemic drug but a medical device/hemostatic agent.
| Onset | Duration | Bioavailability |
|---|---|---|
| Immediate (polymerization occurs within 10-60 seconds upon application to a moist surface). | The polymer film typically sloughs off with the natural exfoliation of the epidermis in 5 to 10 days. For internal vascular applications, the embolic effect is permanent. | Not applicable (N/A). It is a topical/local acting agent with no systemic absorption intended. |
2. Mechanism of Action
n-Butyl-2-cyanoacrylate (n-BCA) is a monomeric liquid. Its mechanism is physical and chemical, not pharmacological. Upon contact with anions present in moisture (e.g., OH- ions in water, blood, tissue fluids), it undergoes rapid anionic polymerization. This exothermic reaction forms long chains of poly(n-butyl-2-cyanoacrylate), creating a solid, flexible film that binds to the underlying tissue. This film acts as a mechanical barrier, approximates wound edges, and provides hemostasis by sealing small vessels.
3. Indications & Uses
- Topical closure of surgical skin incisions and traumatic lacerations (as an adjunct to or replacement for sutures/staples)
- Embolization of cerebral arteriovenous malformations (AVMs) and fistulas (when mixed with ethiodized oil for radiopacity and controlled polymerization)
- Embolization of gastric varices (e.g., via BRTO - Balloon-occluded Retrograde Transvenous Obliteration procedure)
4. Dosage & Administration
Adult Dosage: Topical: Apply the minimal amount (1-2 drops) needed to form a thin film over the approximated wound edges. 1ml vial is typically sufficient for multiple small incisions or a single long incision. Embolization: Dose is highly variable and determined by the interventional radiologist/neurosurgeon based on AVM/variceal size and flow dynamics. It is often diluted with ethiodized oil (e.g., Lipiodol) in ratios from 1:1 to 1:4.
Administration: 1. For topical use: Clean and dry wound area as much as possible. Approximate wound edges with fingers, forceps, or subcutaneous sutures. Hold applicator tip 0.5-1 cm above wound. Apply in a continuous, thin line along the length of the incision. Allow 30-60 seconds to polymerize. Do not apply in a thick layer or between wound edges. 2. For embolization: A specialized catheter delivery system is used under fluoroscopic guidance. The n-BCA is mixed with ethiodized oil for visualization. Injection must be precise and rapid to avoid catheter adhesion. The procedure is performed by a trained specialist in an angiography suite.
5. Side Effects
Common side effects may include:
- Transient localized warmth or burning sensation during polymerization
- Erythema (redness) around application site
- Itching or mild dermatitis under the film
- Visible, slightly raised polymer film on skin
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Anticoagulants (Warfarin, DOACs) / Antiplatelets (Clopidogrel, Aspirin) | Increased risk of bleeding at site before adhesive application; may compromise hemostatic efficacy of the glue. No direct interaction with polymer. | Moderate |
| Topical Antibiotics (Neomycin, Bacitracin) or Antiseptics (Povidone-Iodine) | Application under the glue film may trap moisture, preventing polymerization or promoting infection. Apply adhesive only to clean, dry skin. | Moderate |
| Topical Corticosteroids | May impair wound healing and increase risk of dehiscence when used under adhesive. | Moderate |
7. Patient Counselling
- DO keep the glued area clean and dry for the first 24-48 hours.
- DO report any signs of infection (increased redness, swelling, pain, pus, fever).
- DON'T pick, scratch, or peel the glue film. Let it fall off naturally (5-10 days).
- DON'T apply ointments, creams, or oils directly on the glue, as they may cause it to soften and detach early.
- DON'T soak the area in water (e.g., swimming, long baths) for prolonged periods in the first week.
- DON'T expose the area to direct sunlight excessively, as it may cause hyperpigmentation.
8. Toxicology & Storage
Overdose: Overdose' is not a systemic concept. Local overdose manifests as: 1) Thick, rigid polymer film that cracks and fails prematurely. 2) Excessive exothermic reaction causing thermal tissue injury. 3) In embolization, non-target embolization leading to ischemia/infarction of brain, lungs, or other organs.
Storage: Store in a cool, dry place. Protect from moisture. Store at room temperature (15-25°C). Do not refrigerate or freeze. Keep in the original sealed pouch until use. The vial is for single-use only; discard any unused portion. Do not use if the vial is cracked or the seal is broken. Keep out of reach of children.