Thor Laser Atherectomy for Peripheral Artery Disease

(THOR Trial)

Recruiting at 13 trial locations

Overseen By Clarice Scofield

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Philips Clinical & Medical Affairs Global

Must not be taking: Antibiotics, Antiplatelets, Anticoagulants, others

Disqualifiers: Active infection, Pregnancy, Recent stroke, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 6

Duration: 1 day

155 Participants Needed

Trial Summary

Do I need to stop my current medications for the trial?

The trial protocol does not specify if you need to stop taking your current medications. However, if you have a known contraindication to aspirin or antiplatelet/anticoagulant therapies, you may not be eligible to participate.

What data supports the effectiveness of the treatment Thor Laser Atherectomy for Peripheral Artery Disease?

Research shows that laser atherectomy, a technique used in the Thor treatment, has been used successfully in niche patients with peripheral artery disease, although more studies are needed to confirm long-term benefits. ^{1 2 3 4 5}

Is Thor Laser Atherectomy safe for humans?

Studies on laser atherectomy, including the Phoenix system and excimer laser atherectomy, show that it is generally safe for treating peripheral artery disease, though there can be complications. These studies provide safety data for similar treatments, indicating that while generally safe, there are risks involved. ^{1 2 6 7 8}

How does the Thor Laser Atherectomy treatment differ from other treatments for Peripheral Artery Disease?

Thor Laser Atherectomy is unique because it uses precision laser energy with shallow tissue penetration and safer ultraviolet wavelengths, reducing the risk of vessel damage compared to older laser technologies. This makes it particularly beneficial for high-risk patients with complex peripheral vascular disease, especially in cases where traditional surgical options are not viable. ^{1 9 10 11 12}

What is the purpose of this trial?

The goal of this clinical trial is to test the Thor system in adult (≥ 18 year old) patients with de novo (new, never treated) calcified lesions in infrainguinal (leg) arteries (peripheral artery disease or PAD). The main question\[s\] it aims to answer are: * Is the Thor system safe in treating these lesions * Does the Thor system work to treat these lesions Participants will: * Receive treatment with the Thor system * Have follow-up visits at Discharge, 30 days, 6 months, and 12 months

Research Team

Pradeep Nair, MD

Principal Investigator

Cardiovascular Institute of the South (CIS)

Elizabeth Genovese

Principal Investigator

University of Pennsylvania

Eligibility Criteria

Adults over 18 with new, untreated calcified leg artery blockages (PAD) who can walk on their own or with help from non-motorized devices. They must have a life expectancy over a year and agree to follow the study's rules, including consent form signing and attending follow-up visits.

Inclusion Criteria

Patient agrees to participate and to comply with the protocol by signing an IRB approved patient consent form

Life expectancy >12 months

I can walk on my own or with help from devices like canes.

Exclusion Criteria

Known allergy to contrast media that cannot adequately be premedicated prior to study procedure

I am scheduled for a major leg amputation above the ankle.

The use of specialty balloons, re-entry or additional atherectomy devices

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

1 visit (in-person)

Treatment

Participants receive treatment with the Thor system, including potential use of adjunctive devices such as angioplasty balloons, drug-coated balloons, stents, and filters

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment with follow-up visits at Discharge, 30 days, 6 months, and 12 months

12 months

4 visits (in-person)

Treatment Details

Interventions

• Thor

Trial Overview The THOR IDE Study is evaluating the safety and effectiveness of the Thor laser atherectomy system in treating newly diagnosed calcified lesions in patients' leg arteries. Participants will be treated with this system and monitored for up to one year.

Participant Groups

Group I: Thor Treatment Experimental Treatment 1 Intervention

Treatment with the Thor system

Who Is Running the Clinical Trial?

Philips Clinical & Medical Affairs Global

Lead Sponsor

Trials

61

Recruited

17,600+

Roy Jakobs

Philips Clinical & Medical Affairs Global

Chief Executive Officer since 2022

MBA from Erasmus University Rotterdam

Carla Goulart Peron

Philips Clinical & Medical Affairs Global

Chief Medical Officer since 2023

MD from an unspecified institution

VasCore Vascular Ultrasound Core Lab

Collaborator

Trials

2

Recruited

190+

Syntropic Corelab

Collaborator

Trials

2

Recruited

30+

Massachusetts General Hospital

Collaborator

Trials

3,066

Recruited

13,430,000+

NAMSA

Collaborator

Trials

55

Recruited

21,500+

Findings from Research

Laser atherectomy is a safe and effective treatment for peripheral arterial disease, achieving a technical success rate of 99% with very few complications (less than 1%) in a study of 300 patients over 7 years.

At a mean follow-up of 28 months, 45% of patients experienced significant clinical improvement, but those with diabetes, on dialysis, or with critical limb ischemia were less likely to benefit, highlighting the need for careful patient selection.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Laser Atherectomy for the Treatment of Peripheral Arterial Disease. Mallios, A., Blebea, J., Buster, B., et al.[2022]

In a study of 729 atherectomy procedures performed over five years, complications occurred in 11.1% of cases, with dissection being the most common at 7%.

The length of the treated artery was found to be a significant risk factor for complications, with longer treatment lengths associated with a higher risk, while demographic factors like age, diabetes, and smoking did not predict complications.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Atherectomy-Associated Complications in the Southern California Vascular Outcomes Improvement Collaborative. Azar, Y., DeRubertis, B., Baril, D., et al.[2019]

In a study of 16,838 patients with peripheral arterial disease, those treated with atherectomy had a higher risk of major adverse limb events (38%) compared to those treated with percutaneous transluminal angioplasty (PTA) (33%) and stenting (32%).

Atherectomy was associated with significantly higher risks of major amputation (3.66 times more likely) and any amputation (2.73 times more likely) compared to stenting, indicating that while atherectomy is used for severe cases, it may lead to worse long-term outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Adverse Events After Atherectomy: Analyzing Long-Term Outcomes of Endovascular Lower Extremity Revascularization Techniques. Ramkumar, N., Martinez-Camblor, P., Columbo, JA., et al.[2022]

In a study of 15,281 patients undergoing endovascular interventions for peripheral artery disease (PAD), stent deployment was found to significantly improve overall survival compared to both plain old balloon angioplasty (POBA) and atherectomy, with a 30% lower mortality risk compared to POBA and a 40% lower risk compared to atherectomy.

No significant differences in complications or amputation rates were observed among the different treatment methods, suggesting that while stenting is more effective for survival, the safety profiles of POBA and atherectomy are comparable.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of Peripheral Arterial Disease Interventions on Survival: A Propensity-Score Matched Analysis Using VQI Data. Mukherjee, D., Liu, C., Jadali, A., et al.[2022]

Atherectomy is gaining popularity among specialists for treating peripheral artery disease due to its potential advantages over traditional methods like angioplasty and stenting, particularly in areas with high restenosis rates.

While devices like the SilverHawk atherectomy show promising short-term results, there is a critical need for more long-term data (12 months or more) to establish their efficacy and safety for broader acceptance in clinical practice.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Peripheral atherectomy: a critical review. Bunting, TA., Garcia, LA.[2014]

The Phoenix atherectomy system demonstrated high procedural success rates of 97.3% for non-CLI patients and 98.2% for CLI patients, with a low complication rate of less than 1% after treatment in a study of 500 patients with peripheral artery disease (PAD).

Despite some minor amputations (6.8% in the CLI cohort), there were no major amputations, indicating that the Phoenix system is a safe and effective option for treating PAD, even in patients with advanced disease.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Acute Real-World Outcomes From the Phoenix Post-Approval Registry. Shishehbor, MH., Griffin, J., Crowder, W., et al.[2022]

In a study of 238 procedures for treating acute limb ischemia, both intra-arterial thrombolysis and thromboembolectomy showed similar primary patency and limb salvage rates, indicating that both methods are effective options.

However, the treatments were associated with a significant number of adverse events (AEs), with some leading to serious complications such as irreversible damage and death, highlighting the risks involved in these procedures.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Adverse events after treatment of patients with acute limb ischemia. van der Slegt, J., Flu, HC., Veen, EJ., et al.[2015]

The EXCITE ISR trial, involving 250 patients with chronic peripheral artery disease, found that excimer laser atherectomy (ELA) combined with percutaneous transluminal angioplasty (PTA) significantly improved procedural success rates (93.5% vs. 82.7%) and reduced complications compared to PTA alone.

Patients receiving ELA + PTA experienced a 52% reduction in target lesion revascularization (TLR) at 6 months (73.5% freedom from TLR) and had significantly lower major adverse event rates (5.8% vs. 20.5% at 30 days), indicating both enhanced efficacy and safety of the combined treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Randomized controlled study of excimer laser atherectomy for treatment of femoropopliteal in-stent restenosis: initial results from the EXCITE ISR trial (EXCImer Laser Randomized Controlled Study for Treatment of FemoropopliTEal In-Stent Restenosis). Dippel, EJ., Makam, P., Kovach, R., et al.[2022]

Laser atherectomy shows a high initial technical success rate of 88% in treating multivessel infrainguinal disease, particularly in patients with critical limb ischemia, as evidenced by a study of 40 patients over an average follow-up of 461 days.

However, chronic renal failure and diabetes are significant risk factors for poor outcomes, including amputation and failed revascularization, indicating that careful patient selection is crucial for those with these comorbidities.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Mid-term results with laser atherectomy in the treatment of infrainguinal occlusive disease. Stoner, MC., deFreitas, DJ., Phade, SV., et al.[2022]

Excimer laser atherectomy (LA) demonstrated an immediate technical success rate of 84% in treating complex peripheral vascular disease in 15 high-risk patients, indicating its efficacy as a revascularization technique.

At a 2-year follow-up, 46% of patients who were successfully treated with LA remained alive, with half of them showing stable symptoms without the need for major amputation, highlighting the potential long-term benefits of this approach.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Laser atherectomy for lower extremity revascularization: An adjunctive endovascular treatment option. Zhou, W., Bush, RL., Lin, PH., et al.[2006]

Atherectomy techniques (ATH) for treating below-the-knee (BTK) arteries in patients with peripheral arterial disease (PAD) show a high safety and efficacy profile, with a 30-day technical success rate of 87.3% based on data from 1062 patients across six studies.

While ATH demonstrates durable outcomes at 12 months, mid-term results indicate increased rates of target limb revascularization (6.6% at 12 months) and major limb adverse events (4.7% at 12 months), suggesting that while ATH is effective, its clinical success may decline over time.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The role of atherectomy in BTK lesions: a systematic review. Pitoulias, AG., Pitoulias, GA.[2022]

Laser thermal balloon angioplasty (LTBA) was effective in treating atherosclerosis obliterans in 37 patients, achieving an initial success rate of 85%, with higher success in iliac lesions (89%) compared to femoropopliteal lesions (81%).

After two years, the cumulative clinical patency rate was 91%, indicating that LTBA is a safe and effective treatment option for peripheral atherosclerosis, with only minor complications observed and no major complications reported.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Two-year follow-up after laser thermal balloon angioplasty (LTBA) in lower extremities: initial experience. Masotti, M., Riambau, V., Crexells, C., et al.[2019]

References

1. Netherlands pubmed.ncbi.nlm.nih.gov

Laser Atherectomy for the Treatment of Peripheral Arterial Disease. [2022]

2. Netherlands pubmed.ncbi.nlm.nih.gov

Atherectomy-Associated Complications in the Southern California Vascular Outcomes Improvement Collaborative. [2019]

3. England pubmed.ncbi.nlm.nih.gov

Adverse Events After Atherectomy: Analyzing Long-Term Outcomes of Endovascular Lower Extremity Revascularization Techniques. [2022]

4. Netherlands pubmed.ncbi.nlm.nih.gov

Effects of Peripheral Arterial Disease Interventions on Survival: A Propensity-Score Matched Analysis Using VQI Data. [2022]

5. United States pubmed.ncbi.nlm.nih.gov

Peripheral atherectomy: a critical review. [2014]

6. United States pubmed.ncbi.nlm.nih.gov

Acute Real-World Outcomes From the Phoenix Post-Approval Registry. [2022]

7. Netherlands pubmed.ncbi.nlm.nih.gov

Adverse events after treatment of patients with acute limb ischemia. [2015]

8. United States pubmed.ncbi.nlm.nih.gov

Randomized controlled study of excimer laser atherectomy for treatment of femoropopliteal in-stent restenosis: initial results from the EXCITE ISR trial (EXCImer Laser Randomized Controlled Study for Treatment of FemoropopliTEal In-Stent Restenosis). [2022]

9. United States pubmed.ncbi.nlm.nih.gov

Mid-term results with laser atherectomy in the treatment of infrainguinal occlusive disease. [2022]

10. United States pubmed.ncbi.nlm.nih.gov

Laser atherectomy for lower extremity revascularization: An adjunctive endovascular treatment option. [2006]

11. Italy pubmed.ncbi.nlm.nih.gov

The role of atherectomy in BTK lesions: a systematic review. [2022]

12. United States pubmed.ncbi.nlm.nih.gov

Two-year follow-up after laser thermal balloon angioplasty (LTBA) in lower extremities: initial experience. [2019]