The Safety and Efficacy of Photodynamic Therapy for Femoral Artery Stenosis

The recruitment status of this study is unknown because the information has not been verified recently.
Verified September 2005 by University College London Hospitals.
Recruitment status was  Active, not recruiting
Sponsor:
Collaborator:
UCL/UCLH Clinical Research and Development Fund
Information provided by:
University College London Hospitals
ClinicalTrials.gov Identifier:
NCT00187811
First received: September 9, 2005
Last updated: December 28, 2005
Last verified: September 2005
  Purpose

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.

Hypothesis:

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 Intervention 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

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Single Group Assignment
Masking: Single Blind
Primary Purpose: Treatment
Official Title: Randomised Controlled Trial of Adjuvant Photodynamic Therapy to Reduce Restenosis After Percutaneous Transluminal Angioplasty to the Superficial Femoral Angioplasty

Resource links provided by NLM:


Further study details as provided by University College London Hospitals:

Primary Outcome Measures:
  • Death
  • Procedural complications (occlusion, haematoma)
  • Arterial complications: aneursym, thrombus
  • Surgical revascularisation (Emergency/Elective)
  • Repeat PTA
  • Limb loss

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

Estimated Enrollment: 120
Study Start Date: February 2001
Estimated Study Completion Date: June 2006
Detailed Description:

Background:

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.

  Eligibility

Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

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
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00187811

Locations
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
Investigators
Principal Investigator: Jean R McEwan, MB ChB FRCP University College, London
Study Director: Stephen Bown, PhD FRCP University College, London
  More Information

No publications provided

ClinicalTrials.gov Identifier: NCT00187811     History of Changes
Other Study ID Numbers: 00/0139
Study First Received: September 9, 2005
Last Updated: December 28, 2005
Health Authority: United Kingdom: Medicines and Healthcare Products Regulatory Agency

Keywords provided by University College London Hospitals:
Angioplasty,
Restenosis,
Photodynamic therapy

ClinicalTrials.gov processed this record on July 22, 2014