Red Light Therapy for Peripheral Artery Disease
Palo Alto (17 mi)Overseen byNicole L Lohr, MD,PHD
Age: 18+
Sex: Any
Travel: May be covered
Time Reimbursement: Varies
Trial Phase: N/A
Recruiting
Sponsor: University of Alabama at Birmingham
No Placebo Group
Approved in 1 jurisdiction
Trial Summary
What is the purpose of this trial?This trial involves shining a special red light on the calf muscle of patients with poor leg blood flow due to peripheral artery disease. The goal is to see if this light can improve blood flow by helping the blood vessels work better, possibly through increasing nitric oxide levels.
Is Red Light Treatment a promising treatment for Peripheral Artery Disease?Red Light Treatment, also known as Vascular Infrared Light Therapy, is a promising treatment for Peripheral Artery Disease because it can help open blocked blood vessels, improve blood flow, and offer a less invasive option compared to surgery. This type of therapy can be especially helpful for patients who cannot undergo surgery due to other health issues.245610
What safety data exists for red light therapy in treating peripheral artery disease?The safety data for red light therapy, also known as photodynamic therapy (PDT) or intravascular red light therapy (IRLT), indicates that it is generally safe and well-tolerated. In animal studies, PDT using red light was safe and reduced neointimal hyperplasia in injured arteries. In a human study involving 22 patients undergoing coronary stenting, IRLT was performed successfully without procedural or in-hospital complications, and it showed low rates of restenosis. These findings suggest that red light therapy is safe for vascular applications, although more research is needed to confirm its safety and efficacy in treating peripheral artery disease specifically.7891112
What data supports the idea that Red Light Therapy for Peripheral Artery Disease is an effective treatment?The available research shows that Red Light Therapy, specifically using 670 nm light, can help improve blood flow in cases similar to Peripheral Artery Disease. In a study with mice, this therapy increased blood flow in the legs after 14 days of treatment. The study found that the therapy helps release a substance that widens blood vessels, which can improve circulation. This suggests that Red Light Therapy might be a simple and effective home-based treatment for people with poor blood flow in their legs.123412
Do I have to stop taking my current medications for the trial?The trial protocol does not specify whether you need to stop taking your current medications.
Eligibility Criteria
This trial is for adults aged 18-85 with peripheral artery disease, indicated by an ankle brachial index outside the normal range. It's open to all ethnicities. Excluded are those under 18 or over 85, pregnant women, individuals sensitive to perflutren contrast agents, those with uncontrolled medical conditions like high blood pressure or sickle cell disease, and people who can't understand the consent process.Inclusion Criteria
I have been diagnosed with peripheral artery disease.
I am between 18 and 85 years old and have been diagnosed with peripheral artery disease.
Exclusion Criteria
I am younger than 18 or older than 85.
I have high blood pressure in the lungs.
I have sickle cell disease.
I do not have any uncontrolled medical conditions.
Treatment Details
The study tests a single five-minute exposure of red light therapy on the lower leg muscle in patients with peripheral artery disease. The aim is to see if this treatment improves blood flow as measured by ultrasound after injecting a special contrast agent. Blood samples will also be taken to check for changes in nitric oxide levels.
1Treatment groups
Experimental Treatment
Group I: Red Light treatmentExperimental Treatment2 Interventions
This is a single arm design. All subjects will be enrolled to have peripheral blood flow measured before, during, and after red light exposure.
Find a clinic near you
Research locations nearbySelect from list below to view details:
Medical College of WisconsinMilwaukee, WI
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Who is running the clinical trial?
University of Alabama at BirminghamLead Sponsor
Medical College of WisconsinLead Sponsor
References
Vascular applications of lasers. [2019]There have been major advances in laser technology and in our understanding of the effects of laser energy on blood vessels. This, in turn, has led to the many clinical applications of lasers in patients with vascular disease. The clinical results of laser endarterectomy, laser angioplasty, laser-assisted balloon angioplasty, laser-assisted vascular anastomoses, and the future of lasers in cardiovascular disease are discussed.
Current status of laser angioplasty. [2007]Laser energy transmitted through fiberoptic systems can recanalize totally occluded peripheral arteries and improve extremity perfusion in selected patients with peripheral vascular disease. Such a technique is obviously appealing in that it (1) reduces the morbidity currently associated with the surgical treatment of symptomatic peripheral atherosclerosis, and (2) allows treatment of patients currently excluded from therapy by the presence of other severe medical problems or relatively mild symptoms. Unfortunately, current delivery systems allow recanalization of only a small channel by laser energy alone, and channel enlargement using balloon dilation is usually required. Clinical trials of laser angioplasty (laser-assisted balloon angioplasty) have shown acceptable results in the treatment of stenosis or short occlusions in the iliac and superficial femoral arteries, but results in patients with long occlusions or disease below the knee remain well below the results achieved by standard surgical therapy. Thus the impact of laser angioplasty on the treatment of peripheral vascular disease is limited at present and much work remains to be done to further develop this exciting new therapy for the treatment of peripheral vascular disease.
Vascular applications of laser. [2007]The authors review the current experimental and clinical literature relating to the use of lasers in peripheral vascular disease. During the past few years, significant strides have been made in effective harnessing of laser energy for percutaneous revascularization. However, the role of lasers in treating vascular disease is not yet clear. Thus current application of laser technology in this area should be considered experimental until adequate clinical studies confirm its efficacy.
The role of lasers in the management of peripheral vascular disease. [2017]Although it has been almost twenty-five years since the first studies of McGuff et al, who employed the laser for atheroablation, problems still require resolution. The various laser wavelengths from ultraviolet through visible to infrared have been employed for atheroablation. The laser's greatest appeal and the most spectacular results have been in reopening channels in totally occluded vessels. The laser's greatest problem has been damage of the arterial wall and even perforation. The purpose of this presentation is to clarify the present status of available lasers for the treatment of peripheral vascular disease of the lower extremities. To this end, the initial experience with angioscopically guided laser-assisted angioplasty with a new hybrid laser probe is reported.
Direct argon laser exposure for recanalization of peripheral arteries: early results. [2007]Direct laser light, in combination with percutaneous transluminal angioplasty (PTA), was used to recanalize atherosclerotic peripheral arteries. Argon laser energy was controlled with an optical assembly and aligned with a special centering/dilation balloon so that plaque tissue absorbed laser energy directly and was vaporized. A channel was thereby created with multiple 10-W laser exposures (2-10 seconds), and conventional angioplasty was then performed. Recanalization was achieved in 33 of 36 procedures (92%), in 23 femoropopliteal (mean length, 9 cm) and three iliac total occlusions and ten femoropopliteal high-grade stenoses, with the three failures occurring in the first group. Complications included two emboli, six moderate groin hematomas, and one laser perforation. While these results are preliminary (mean follow-up, 3 months), direct laser angioplasty appears to be a useful adjunct to PTA for treating atherosclerotic arteries.
Percutaneous laser recanalisation of femoropopliteal occlusions using continuous wave Nd-YAG laser and sapphire contact probe delivery system. [2019]A conventional continuous wave Nd-YAG medical laser system delivered by transparent sapphire tipped optical fibres was used for percutaneous recanalisation of 32 chronic femoropopliteal occlusions in 27 patients (19 men, eight women; median age 68 years, range 46-83 years). Twenty-four patients had severe intermittent claudication and three had critical ischaemia. The median occlusion length was 8 cm (range 3-35 cm) and lesions were not negotiable by guidewire. Laser energy was delivered at powers of 10-15 Watts using intermittent 1 second emissions (mean total energy 315 Joules, range 30-1015]). The sapphire tips used were 1.8 to 3.0 mm diameter. After laser recanalisation adjunctive balloon dilatation was necessary to widen the resulting lumen. All patients received anti-platelet therapy. Initial clinical success was achieved in 22 limbs (69%) with symptomatic relief and increase in mean (+/- S.D.) ankle-brachial pressure ratio from 0.52 (+/- 0.25) to 0.80 (+/- 0.21) [Mann-Whitney U, p
Reduction in the response to coronary and iliac artery injury with photodynamic therapy using 5-aminolaevulinic acid. [2019]Photodynamic therapy (PDT) uses red light (non-thermal, non-ionising) to activate a previously administered photosensitizing drug. This inhibits neointimal hyperplasia in injured arteries in small animals where it appears safe and well tolerated. Our aim was to develop a method for percutaneous application of PDT to iliac and coronary arteries in a large animal model and investigate its influence on the remodeling and intimal hyperplastic response to balloon injury.
Intravascular Red Light Therapy after Coronary Stenting Ñ Angiographic and Clinical Follow-up Study in Humans. [2019]In animal models of coronary restenosis, intravascular red light therapy (IRLT) using a diode laser source has been shown to reduce neointimal hyperplasia following balloon-induced injury and coronary stenting. We studied the safety and efficacy of catheter-based IRLT for preventing restenosis after coronary stenting in 22 patients with angina pectoris. IRLT was performed using a diode laser (650 nm) at an energy level of 10 megawatts delivered through a rapid exchange balloon system containing the fiberoptics. The procedure was successful in all patients, with no procedural or in-hospital complications. Two patients with recurrence of symptoms had angiography at 3 and 4.1 months respectively. Angiographic follow-up was also done after 6 months in the 20 remaining asymptomatic patients. The mean minimal lumen diameter (MLD) for the whole group at 6 months follow-up was 2.57 +/- 0.62 mm. The calculated late lumen loss was 0.49 +/- 1.12 mm with a late loss index of 0.21 +/- 0.54. Four patients (2 symptomatic and 2 asymptomatic) in the series developed angiographic restenosis. Clinical events at follow-up of 10.9 +/- 3.5 months were repeat angioplasty in 2 patients for symptomatic restenosis with a 91% event free survival. These preliminary results demonstrate that IRLT after coronary artery stenting is safe and feasible; it is associated with low rates of angiographic indices of restenosis.
Arterial wall strength after endovascular photodynamic therapy. [2013]Vascular photodynamic therapy (PDT) inhibits intimal hyperplasia (IH) induced by angioplasty in rat iliac arteries by eradicating the proliferating smooth muscle cells. This process may jeopardise the structure and strength of the arterial wall, reflected by a decreased bursting pressure.
Excimer laser-assisted angioplasty for infrainguinal artery disease. [2022]After nearly 2 decades of research and experimentation with laser-assisted angioplasty, the xenon-hydrogen chloride excimer laser emerged as the laser device best suited for the treatment of peripheral artery disease. Emitting light at a wavelength of 308 nm, this laser utilizes a nonthermal mechanism of action to ablate plaque and thrombus in powerful discrete pulses. The excimer laser is particularly useful for the treatment of complex conditions, such as long chronic occlusions in the superficial femoral artery and in those patients with below-the-knee disease and critical limb ischemia who may not be good candidates for bypass surgery. A number of investigators have noted that the excimer laser will often uncover distinct, more focal lesions in what appears to be an extensive and complex occlusion, potentially simplifying treatment of these segments. The Laser Angioplasty for Critical Limb Ischemia phase 2 trial, a prospective registry of 145 patients at 11 US and 3 German sites, achieved good procedural success (86%) and an excellent 6-month limb salvage rate (93%). A new specialized deflecting sheath designed to direct excimer ablation in blockages of the larger main arteries above the knee has produced clinical improvement in a single-center feasibility study and a 16-center prospective registry. Less promising results were reported in a single-center real-world retrospective registry, warranting careful case selection with this device for patients with diabetes and renal failure.
Light-induced vasodilation of coronary arteries and its possible clinical implication. [2015]Low-level laser therapy and light-emitting diodes (LED) are increasingly used in phototherapy. Their therapeutic effects are at least partly mediated by light-induced vasodilation. The aim of this study was to determine the effect of different light sources on coronary arteries.
In Vivo Characterization of a Red Light-Activated Vasodilation: A Photobiomodulation Study. [2023]Nitric oxide dependent vasodilation is an effective mechanism for restoring blood flow to ischemic tissues. Previously, we established an ex vivo murine model whereby red light (670 nm) facilitates vasodilation via an endothelium derived vasoactive species which contains a functional group that can be reduced to nitric oxide. In the present study we investigated this vasodilator in vivo by measuring blood flow with Laser Doppler Perfusion imaging in mice. The vasodilatory nitric oxide precursor was analyzed in plasma and muscle with triiodide-dependent chemiluminescence. First, a 5-10 min irradiation of a 3 cm2 area in the hind limb at 670 nm (50 mW/cm2) produced optimal vasodilation. The nitric oxide precursor in the irradiated quadriceps tissue decreased significantly from 123 ± 18 pmol/g tissue by both intensity and duration of light treatment to an average of 90 ± 17 pmol/g tissue, while stayed steady (137 ± 21 pmol/g tissue) in unexposed control hindlimb. Second, the blood flow remained elevated 30 min after termination of the light exposure. The nitric oxide precursor content significantly increased by 50% by irradiation then depleted in plasma, while remained stable in the hindlimb muscle. Third, to mimic human peripheral artery disease, an ameroid constrictor was inserted on the proximal femoral artery of mice and caused a significant reduction of flow. Repeated light treatment for 14 days achieved steady and significant increase of perfusion in the constricted limb. Our results strongly support 670 nm light can regulate dilation of conduit vessel by releasing a vasoactive nitric oxide precursor species and may offer a simple home-based therapy in the future to individuals with impaired blood flow in the leg.