Varicose Veins of Lower LimbPhase 2CLACSONCT07073742
CLaCS Using 0.2% Aetoxysklerol Foam and 70% Glucose for the Treatment of Lower Limb Telangiectasias
A Phase 2 study testing CLaCS in people with Varicose Veins of Lower Limb and Spider Veins, run by Charles University, Czech Republic.
Trial summary
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. Read more about this study
- Who is it for?
- Any ageHealthy volunteers can take part
- Conditions the study is for
- Varicose Veins of Lower Limb, Spider Veins, Reticular Leg Veins
- What is being tested?
- CLaCS
- Type of treatment
- Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 240 participants
- Where
- No sites listed yet
- Study dates
- 1 Sep 2025to 1 Sep 2028
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Who may be able to join
- Signed informed consent.
- Age > 18 years.
- CEAP classification C1 (telangiectasias only).
- Treated area for the study must be ≤ 20x20 cm on the lower limb - thigh.
Who cannot join
- Reflux in trunk veins or perforators.
- Active skin infection at the treatment site.
- Presence of reticular veins.
- Previous sclerotherapy/CLaCS in the target area.
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Randomized, Controlled, Non-Inferiority Trial on the Efficacy of CLaCS Using 0.2% Aetoxysklerol Foam and 70% Glucose for the Treatment of Lower Limb Telangiectasias
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.
Read the detailed description
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.
- Being tested
- CLaCS
- Keywords
- Telangiectasia, CryoLaser and CryoSclerotherapy, Cosmetic phlebology, AI prediction
- Medical subject headings
- Telangiectasis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CLaCSProcedure or surgery
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).
| Study group | Role | What they receive |
|---|---|---|
| CLaCS with 70% Glucose (Control Group) | Active comparator | 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. Receives: Procedure: CLaCS |
| CLaCS with 0.2% Polidocanol Foam (Aetoxysklerol) - Test Group | Active comparator | 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. Receives: Procedure: CLaCS |
What is being measured
The primary outcome is the main question the study is designed to answer.
To assess the rate of telangiectasia elimination using CLaCS with two types of sclerosants (G-70 and AET-0.2).
Measured: 8 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Jul 2025
- Study start1 Sep 2025 (estimated)
- Primary completion1 Sep 2027 (estimated)
- Study completion1 Sep 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Varicose Veins of Lower LimbStudies of the same condition, open and under way.
- More trials run by Charles University, Czech RepublicThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 240 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Charles University, Czech Republic
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07073742
- Sponsor's protocol ID
- 111111
- Acronym
- CLACSO
- Status last verified
- Jul 2025
- First submitted
- 10 Jul 2025
- Last updated
- 18 Jul 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Bertanha M, Yoshida WB, Bueno de Camargo PA, Moura R, Reis de Paula D, Padovani CR, Sobreira ML. Polidocanol Plus Glucose Versus Glucose Alone for the Treatment of Telangiectasias: Triple Blind, Randomised Controlled Trial (PG3T). Eur J Vasc Endovasc Surg. 2021 Jan;61(1):128-135. doi: 10.1016/j.ejvs.2020.07.007. Epub 2020 Aug 7.
PubMed 32778489Miyake RK, Chi YW, Franklin IJ, Gianesini S. State of the art on cryo-laser cryo-sclerotherapy in lower limb venous aesthetic treatment. J Vasc Surg Venous Lymphat Disord. 2020 Sep;8(5):893-895. doi: 10.1016/j.jvsv.2020.01.003. Epub 2020 Mar 14.
PubMed 32179040Gonzalez Ochoa AJ, Carrillo J, Manriquez D, Manrique F, Vazquez AN. Reducing hyperpigmentation after sclerotherapy: A randomized clinical trial. J Vasc Surg Venous Lymphat Disord. 2021 Jan;9(1):154-162. doi: 10.1016/j.jvsv.2020.06.019. Epub 2020 Jul 30.
PubMed 32739509
Study at a glance
From the registry record, last updated by the sponsor on 18 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Randomized, Controlled, Non-Inferiority Trial on the Efficacy of CLaCS Using 0.2% Aetoxysklerol Foam and 70% Glucose for the Treatment of Lower Limb Telangiectasias
- ClinicalTrials.gov ID
- NCT07073742
- Acronym / sponsor ID
- CLACSO / 111111
- Keywords
- Telangiectasia, CryoLaser and CryoSclerotherapy, Cosmetic phlebology, AI prediction
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 240 participants (estimated)
- Lead sponsor
- Charles University, Czech RepublicUniversity, hospital or other
- Study start
- 1 Sep 2025 (estimated)
- Primary completion
- 1 Sep 2027 (estimated)
- Study completion
- 1 Sep 2028 (estimated)
- First posted
- 18 Jul 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| CLaCS with 70% Glucose (Control Group) | Active comparator | Procedure: CLaCSParticipants 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. |
| CLaCS with 0.2% Polidocanol Foam (Aetoxysklerol) - Test Group | Active comparator | Procedure: CLaCSParticipants 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. |
Who may qualify
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (4 listed)
- Signed informed consent.
- Age > 18 years.
- CEAP classification C1 (telangiectasias only).
- Treated area for the study must be ≤ 20x20 cm on the lower limb - thigh.
Key exclusion criteria (4 listed)
- Reflux in trunk veins or perforators.
- Active skin infection at the treatment site.
- Presence of reticular veins.
- Previous sclerotherapy/CLaCS in the target area.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| CLaCSCLaCS is hybrid outpatient procedure combining Nd:YAG 1064 nm laser treatment with injection of a sclerosant (either 70% glucose or 0.2% polidocanol foam). | Procedure or surgery | CLaCS with 0.2% Polidocanol Foam (Aetoxysklerol) - Test Group, CLaCS with 70% Glucose (Control Group) |
Primary outcome
To assess the rate of telangiectasia elimination using CLaCS with two types of sclerosants (G-70 and AET-0.2).
Time frame: 8 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Jul 2025.
- Results publication: PubMed 32778489Bertanha M, Yoshida WB, Bueno de Camargo PA, Moura R, Reis de Paula D, Padovani CR, Sobreira ML. Polidocanol Plus Glucose Versus Glucose Alone for the Treatment of Telangiectasias: Triple Blind, Randomised Controlled Trial (PG3T). Eur J Vasc Endovasc Surg. 2021 Jan;61(1):128-135. doi: 10.1016/j.ejvs.2020.07.007. Epub 2020 Aug 7.
- Results publication: PubMed 32179040Miyake RK, Chi YW, Franklin IJ, Gianesini S. State of the art on cryo-laser cryo-sclerotherapy in lower limb venous aesthetic treatment. J Vasc Surg Venous Lymphat Disord. 2020 Sep;8(5):893-895. doi: 10.1016/j.jvsv.2020.01.003. Epub 2020 Mar 14.
- Results publication: PubMed 32739509Gonzalez Ochoa AJ, Carrillo J, Manriquez D, Manrique F, Vazquez AN. Reducing hyperpigmentation after sclerotherapy: A randomized clinical trial. J Vasc Surg Venous Lymphat Disord. 2021 Jan;9(1):154-162. doi: 10.1016/j.jvsv.2020.06.019. Epub 2020 Jul 30.
- Individual participant dataSharing planned: No
Related trials for Varicose Veins of Lower Limb
Recruiting
PAW-Hydrogel for Chronic Wound Healing
Diabetic Foot Ulcer (DFU), Pressure Ulcer (PU)
Not yet recruiting
Mindfulness Intervention on Minimally Invasive Vascular Surgery
Anxiety, Pain
Active, not recruitingObservational study
Pain During Heat Treatment for Lower Extremity Varicose Veins: Radiofrequency vs. Microwave
Lower Extremity Varicose Veins, Radiofrequency Ablation
Recruiting
Vacuum Compression Therapy and Tissue Oxygenation in Chronic Leg Ulcers
Leg Ulcers, Leg Ulcers Venous
Recruiting
Dose-Response Structured Calf Muscle Pump Activation Strategies Versus Unsupervised Home Walks
Venous Ulcer of Leg
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing CLaCS in people with Varicose Veins of Lower Limb and Spider Veins, run by Charles University, Czech Republic.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 18 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Peter Balaz, professor (+420776882216, balazp@fnkv.cz), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To assess the rate of telangiectasia elimination using CLaCS with two types of sclerosants (G-70 and AET-0.2). (time frame: 8 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07073742, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Jul 2025.