Cyanoacrylate closure is a non-surgical varicose vein treatment in which a medical-grade adhesive is delivered through a thin catheter to seal an incompetent saphenous vein from the inside. Two dedicated closure devices dominate the published literature on this technique: VenaSeal, developed by Medtronic, and VenaBLOCK, developed by INVAMED. Both eliminate the need for thermal energy and tumescent anesthesia, but they differ in adhesive formulation, delivery hardware, and application technique. This article summarizes how each system works and what peer-reviewed comparisons have examined — so clinicians can read the evidence in context.
What Is Cyanoacrylate Vein Closure?
Cyanoacrylate closure (also called vein glue treatment) belongs to the non-thermal, non-tumescent (NTNT) family of endovenous therapies. A catheter is advanced into the refluxing vein under ultrasound guidance, adhesive is deposited segmentally as the catheter is withdrawn, and manual compression polymerizes the glue, permanently occluding the vein. Because no heat is generated, there is no risk of thermal nerve injury and no need for the multiple tumescent anesthesia injections required by laser or radiofrequency ablation — a key reason cyanoacrylate closure is described as a walk-in, walk-out varicose vein procedure.
The VenaSeal Closure System
VenaSeal uses a proprietary n-butyl-2-cyanoacrylate formulation delivered with a dispenser gun that meters discrete adhesive aliquots, followed by a defined segmental pull-back and compression protocol. It is the most extensively studied cyanoacrylate system: the VeClose randomized trial compared it head-to-head with radiofrequency ablation and reported comparable closure of the great saphenous vein, and multi-year follow-up publications have documented durable results. VenaSeal™ is a trademark of Medtronic. Our separate academic overview of the VenaSeal closure system covers its evidence base in more detail.
The VenaBLOCK Closure System
VenaBLOCK is INVAMED's n-butyl-2-cyanoacrylate closure system, delivered through an application catheter with an integrated guiding light that transilluminates the catheter tip position through the skin — an orientation aid during adhesive deposition. Twelve-month results with the guiding-light catheter were published in the journal Vascular (DOI: 10.1177/1708538118770548), and the system has since appeared in comparative and cohort studies of endovenous cyanoacrylate ablation. The delivery approach uses continuous, ultrasound-monitored adhesive application during withdrawal rather than a fixed-aliquot dispenser protocol.
What Does the Head-to-Head Evidence Say?
A comparative analysis of the VenaBlock and VenaSeal systems for endovenous cyanoacrylate closure in chronic venous insufficiency was published in International Angiology in 2024 (DOI: 10.23736/S0392-9590.24.05143-5), examining the two devices' outcomes within one treatment concept. Readers should consult the full study for endpoints and results; as with any single comparison, findings reflect the enrolled population and technique used at the study centers. The broader literature positions both systems as effective options within the cyanoacrylate class, with device choice shaped by availability, physician training, delivery preference, and cost considerations in each market. INVAMED's complete list of peer-reviewed studies is maintained in the Clinical Evidence Library.
Practical Differences at a Glance
For clinicians evaluating the two closure devices, the practical distinctions reported in the literature concentrate in four areas. Adhesive delivery: metered aliquots via dispenser gun (VenaSeal) versus continuous light-guided application (VenaBLOCK). Tip localization: ultrasound alone versus ultrasound plus transillumination from the guiding light. Procedure protocol: both are tumescent-free and heat-free, performed under local anesthesia at the access site only. Post-procedure course: published protocols for both systems describe immediate ambulation, with many centers omitting routine compression stockings — an individual clinical decision. Neither system requires the staged pull-back timing of thermal ablation, and both avoid thermal nerve injury risk entirely.
Frequently Asked Questions
Is cyanoacrylate closure really a non-surgical varicose vein treatment?
Yes. The procedure requires only a needle puncture for catheter access — no incisions, no general anesthesia, and no vein stripping. It is performed in an outpatient setting, and most patients resume normal activity the same or next day.
Which closure device is better for a given patient?
Published comparisons do not establish a universal winner; both systems occlude the target vein effectively in reported series. The treating physician weighs anatomy, vein diameter, device availability, and personal technique experience when selecting a system.
Do patients need compression stockings after vein glue treatment?
Many published cyanoacrylate protocols omit routine post-procedure compression, which is one of the frequently cited practical advantages over thermal ablation. The final decision rests with the treating physician based on the individual case.
Does vein glue stay in the body permanently?
Yes. The polymerized adhesive remains in the sealed vein, which is gradually incorporated by the body through a chronic inflammatory-fibrotic response, similar in end result to other ablation methods that leave the treated vein in place.
Related on INVAMED
Further reading: how cyanoacrylate closure works, cyanoacrylate closure vs endovenous laser ablation, radiofrequency ablation vs cyanoacrylate closure, and the complete varicose vein treatment portfolio.
VenaSeal™ is a trademark of Medtronic. All product names are used for identification and comparison purposes only.
Device availability and regulatory status vary by country. Please contact INVAMED or your authorized local distributor for current regulatory information applicable to your region.