A Phase 2 interventional study of CLaCS in Varicose Veins of Lower Limb, Spider Veins and Reticular Leg Veins, sponsored by Charles University, Czech Republic. Not yet recruiting. Per ClinicalTrials.gov, last updated 2025-07-18.
Sponsored by Charles University, Czech Republic · Phase 2, Interventional, and Treatment
This randomized, controlled, non-inferiority trial aims to compare the efficacy of two sclerosants used in the CLaCS (CryoLaser and CryoSclerotherapy) method for treating telangiectasias and reticular varicose veins. CLaCS is an advanced outpatient procedure that combines Nd\:YAG laser treatment with sclerotherapy to enhance vein closure and cosmetic outcomes while minimizing side effects. The trial will compare the standard 70% glucose sclerosant with a novel 0.2% Aetoxysklerol (polidocanol) foam prepared using the VARIXIO system. Despite widespread use of CLaCS, no head-to-head studies currently exist comparing these two agents. This study aims to determine whether low-concentration Aetoxysklerol foam is non-inferior to 70% glucose in achieving effective telangiectasia elimination.
Telangiectasias and reticular varicose veins affect up to 80% of the population, significantly impacting quality of life beyond cosmetic concerns. In advanced stages (e.g., corona phlebectatica), they may contribute to the progression of chronic venous disease. CLaCS (CryoLaser and CryoSclerotherapy) is currently regarded as the most advanced outpatient technique for managing these lesions. It integrates two modalities: laser-induced vasospasm of feeder veins using Nd:YAG 1064 nm laser, and subsequent sclerotherapy of the visible telangiectasias. This hybrid approach aims to maximize efficacy while minimizing adverse effects associated with each component when used in isolation.
The original CLaCS protocol utilizes 70% hypertonic glucose as the sclerosant, a substance that induces endothelial dehydration, fibrosis, and gradual obliteration of the treated veins. While glucose is widely considered safe and well tolerated, its efficacy may be limited in certain patient populations or lesion types.
Alternatively, polidocanol (Aetoxysklerol), a detergent-type sclerosant, is routinely used in concentrations of 0.5-3% for sclerotherapy. It disrupts the endothelial surface, triggering inflammation, spasm, and thrombosis, ultimately resulting in vessel closure. Recent advances in delivery techniques, such as the VARIXIO system, allow for the generation of a highly stable foam using very low concentrations of Aetoxysklerol (e.g., 0.2%). This approach may retain therapeutic efficacy while potentially reducing complications like hyperpigmentation, pain, or matting.
To date, no clinical trials have directly compared the effectiveness of CLaCS using different sclerosants. This prospective, randomized, controlled, non-inferiority trial aims to evaluate whether 0.2% Aetoxysklerol foam is non-inferior to 70% glucose in the treatment of lower limb telangiectasias using the CLaCS method. Patients will be randomly assigned to receive CLaCS treatment with either 70% glucose or 0.2% polidocanol foam, with outcomes assessed by blinded evaluators using standardized pre- and post-treatment photography and patient-reported satisfaction.
The primary endpoint is the proportion of treated areas showing clinically significant clearance of telangiectasias at 8 weeks post-treatment. Secondary endpoints include patient satisfaction and comparison of treatment outcomes with AI-based predictive modeling. This trial will provide critical evidence to inform sclerosant selection in CLaCS procedures and may support broader adoption of low-dose detergent-based foams as a safe and effective alternative to glucose.
69 studies on the registry are indexed under Telangiectasis; 12 are open to participants now.
This study's planned enrollment of 240 is above the median of 30 across 59 interventional studies indexed under Telangiectasis.
Browse Telangiectasis studies →Charles University, Czech Republic is the lead sponsor of 228 studies on the registry; 76 are open to participants now.
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Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants in this group will undergo the CLaCS procedure using Nd:YAG 1064 nm laser followed by intravascular injection of 70% glucose as the sclerosant. This represents the standard CLaCS protocol and serves as the control arm.
Procedure: CLaCS
Participants in this group will receive the same laser treatment (Nd:YAG 1064 nm) as the control group, but the sclerosant will be a 0.2% polidocanol foam, prepared using the VARIXIO system. This arm evaluates the efficacy of a low-concentration detergent-based alternative.
Procedure: CLaCS
CLaCS is hybrid outpatient procedure combining Nd:YAG 1064 nm laser treatment with injection of a sclerosant (either 70% glucose or 0.2% polidocanol foam).
To assess the rate of telangiectasia elimination using CLaCS with two types of sclerosants (G-70 and AET-0.2).
Time frame: 8 weeks
No study locations are listed for this record.
Plan to share: No
Start is estimated for Sep 2025; primary completion for Sep 2027, 24 months later.
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This study is not yet recruiting, as verified in Jul 2025. You cannot join it, but the record below documents what was studied.
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Charles University, Czech Republic →