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The Safety and Efficacy of Photodynamic Therapy for Femoral Artery Stenosis

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ClinicalTrials.gov Identifier: NCT00187811
Recruitment Status : Unknown
Verified September 2005 by University College London Hospitals.
Recruitment status was:  Active, not recruiting
First Posted : September 16, 2005
Last Update Posted : December 29, 2005
Information provided by:

Study Description
Brief Summary:

Rstenosis is common after angioplasty of atherosclerotic disease of the femoral artery. Pilot study data suggests that adjuvant photodynamic therapy, using delta amino kleavulinic acid as a photosensitiserr is feasible and safe. This study will examine safety in a larger population and,if recruitment numbers allow, efficacy will be assessed.


ALA photodynamic therapy is safe and well tolerated as an adjuvant to angioplasty as a treatment for femoral artery atherosclerotic stenosis or occlusion. A secondary endpoint will be sought : hypothesis : PDT will reduce in restenosis rates following adjuvant photodynamic therapy compared with standard balloon angioplasty in the treatment of superficial femoral arterial disease.

Condition or disease Intervention/treatment Phase
Atherosclerotic Narrowing of the Superficial Femoral Artery Atherosclerotic Occlusion of the Superficial Femoral Artery Procedure: Delta amino leavulinic acid photodynamic therapy Phase 2 Phase 3

Detailed Description:


Percutaneous Transluminal Angioplasty (PTA) is well recognised as a treatment for obstructive vascular disease. Despite an initial high procedural success the technique is limited by the subsequent development of restenosis in up to 50% of patients between 3 and 6 months. ,

The pathological hallmark of restenosis has long been considered to be the development of neointimal hyperplasia consisting of smooth muscle cells and extracellular matrix. We now realise however that both elastic recoil of the vessel and the concept of remodelling are important in determining the overall response of the vessel to injury. Remodelling involves a geometric change in the vessel such that the maximum arterial dimension may increase (positive remodelling) or decrease (negative remodelling). , ,

Despite extensive research no pharmacological or interventional strategy has been shown to have an overwhelming effect on restenosis rates after angioplasty. Recently attention has been focused on the potential of intraluminal radiation therapy (Brachytherapy) and whilst this technique has shown considerable promise there are concerns regarding the long term complications and safety of the ionising radiation for non-malignant disease with reports of vessel wall damage after treatment. ,

Photodynamic therapy is a novel technique that involves the activation of a previously administered photosensitising agent by non thermal laser light. This results in the generation of reactive oxidative products with resulting tissue effects. It is a technique that has been used in the treatment of a variety of malignancies but the realisation that it may influence the response of the vessel wall after balloon injury has been particularly promising. 5 Aminolaevulinic acid (ALA) is a relatively new photosensitising agent which is converted to an active metabolite, Protoporphyrin IX (PPIX) in the biosynthesis of haem. In small animal models photodynamic therapy has been shown to cause medial smooth muscle cell depletion and to reduce the degree of neointimal hyperplasia after injury with no detrimental effects on the mechanical integrity of the vessel wall. , Large animal work using a swine model has confirmed these findings and has also demonstrated that favourable vessel wall remodelling occurs after PDT. Repopulation of the media with smooth muscle cells, after early depletion, has also been demonstrated which is likely to be important when we consider the long term effects of this treatment on the vessel wall.

The use of a large animal model enabled the development of an endovascular system for the delivery of laser light. As a result, and in the light of the findings from large animal studies, it has now been possible to conduct a pilot clinical study looking at the safety and efficacy of adjuvant PDT in patients undergoing repeat PTA for superficial femoral artery (SFA) disease who had restenosed less than 6 months after an earlier angioplasty. In this study it was shown that all patients were asymptomatic 6 months after the procedure with adjuvant PDT there were no arterial or procedural complications. These findings were supported by improvements in non-invasive endpoints and the abscence of significant restenosis as assessed by digital subtraction angiography.

These results were encouraging and we are now in a position to conduct a randomised clinical trial looking at standard balloon angioplasty with and without adjuvant photodynamic therapy in the treatment of peripheral vascular disease.

Study Design

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 120 participants
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Single
Primary Purpose: Treatment
Official Title: Randomised Controlled Trial of Adjuvant Photodynamic Therapy to Reduce Restenosis After Percutaneous Transluminal Angioplasty to the Superficial Femoral Angioplasty
Study Start Date : February 2001
Estimated Study Completion Date : June 2006

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Angioplasty
U.S. FDA Resources

Arms and Interventions

Outcome Measures

Primary Outcome Measures :
  1. Death
  2. Procedural complications (occlusion, haematoma)
  3. Arterial complications: aneursym, thrombus
  4. Surgical revascularisation (Emergency/Elective)
  5. Repeat PTA
  6. Limb loss

Secondary Outcome Measures :
  1. Reccurence of claudication
  2. > 50% loss of initial lumen gain on duplex scanning
  3. PSVR > 2.0
  4. Fall in ABPI
  5. Measured Pre procedure, at 24h then at 1, 3 and 6 months.
  6. A final follow up is planned at 3-5 years

Eligibility Criteria

Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Senior
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Clinical diagnosis of claudication suggested by preliminary Duplex study to be due to superficial femoral artery stenosis or occlusion

Exclusion Criteria:

  • Previous surgical graft to superficial femoral artery Known liver dysfunction Previous history of photosensitivity
Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00187811

United Kingdom
University College London NHS Foundation Trust
London, United Kingdom, WC1P 9LL
Sponsors and Collaborators
University College London Hospitals
UCL/UCLH Clinical Research and Development Fund
Principal Investigator: Jean R McEwan, MB ChB FRCP University College, London
Study Director: Stephen Bown, PhD FRCP University College, London
More Information

ClinicalTrials.gov Identifier: NCT00187811     History of Changes
Other Study ID Numbers: 00/0139
First Posted: September 16, 2005    Key Record Dates
Last Update Posted: December 29, 2005
Last Verified: September 2005

Keywords provided by University College London Hospitals:
Photodynamic therapy