Phase 2 Study to Explore the Effect of Lowering Blood Viscosity in Patients With Treatment-resistant Critical Limb Ischemia
试验速览
- 阶段
- 2 期
- 状态
- 已完成
- 发起方
- 入组人数
- 20
- 试验地点
- 2
- 主要终点
- Major amputation rate (limb salvage rate)
研究概览
简要总结
PAD is caused by an increased flow resistance in atherosclerotic ischemic limbs. The investigators hypothesize that reducing blood viscosity (through controlled phlebotomy), thereby increasing the deformability of red blood cells, should reduce the flow resistance and improve tissue perfusion leading to improved clinical function and a reduction in symptoms.
Preliminary data demonstrates that phlebotomy causes a measurable change in blood viscosity as measured by the home-made rheologic method.
To evaluate the effectiveness of changes in blood viscosity, obtained through controlled phlebotomy, as a therapy to improve functional status associated with atherosclerotic ischemic limbs in pre-amputation patients.
详细描述
The first study is a pilot study and will act as proof of principle. This first study will include 20 patients divided into 2 groups on the basis of a randomized controlled trial: 10 patients in the control group receiving conventional treatment and 10 patients receiving therapeutic phlebotomy to lower blood viscosity. The objective is to evaluate the effect of controlled phlebotomy in patients with Grade 3, Category 5 or 6 chronic critical limb ischemia having tissue loss on Rutherford classification (Fontaine stage IV), end-stage peripheral vascular disease resistant to maximal medical therapy and where revascularization therapy (both percutaneous and surgical) has either proved insufficient or is contra-indicated or declined by the patient, usually resulting in amputation.
The primary outcome parameters will be: the salvage rate of the limb as compared with the salvage rate of the limb with conventional therapy.
Objective classification of improvement in perfusion of the distal extremities using ankle-brachial index (ABI), visual analogue pain scale, and photos.
Subjective classification of improvement in pain scale on critical limbs.
The relationship between alteration in outcome parameters (i.e., the end point is a reduced amputation rate) and blood viscosity will be evaluated as measured by the home-made rheologic methods.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 性别
- Male
- 接受健康志愿者
- 否
入选标准
- •Subjects should have diagnosed Rutherford classification Grade 3, Category 5 or 6 (Fontaine stage IV) treatment-resistant chronic critical limb ischemia having tissue loss, not relieved by maximal medical therapy and they should have exhausted or not be candidates for surgical (other than heart transplant) or percutaneous intervention
- •Age: 18 to 80 years
- •Current non-smokers
- •Estimated 6 month survival rate >90%
- •Concomitant stable medications will be allowed.
- •If the subjects have coronary artery disease established by history, angina pain, EKG, Lab including Troponin I, creatine kinase, lactate dehydrogenase, Echocardiography, Thallium scan or coronary angiography, the subjects should have established a classification of coronary artery involvement by coronary angiography or other procedure with similar precision.
排除标准
- •Low blood pressure (systolic < 120 mmHg)
- •Baseline hematocrit < 30
- •Initial whole blood viscosity measurements below 15 miliPoiseille
结局指标
主要结局
Major amputation rate (limb salvage rate)
时间窗: 5 year follow-up period
The rate of lower limb major amputation (limb salvage rate) was measured in both study arms, during 5 year follow-up period. They would be the evidences of phlebotomy treatment directly.
次要结局
- Time-to-major amputation(5 year follow-up period)
- Mortality rate(5 year follow-up period)
- Blood viscosity measurements(Conducting study periods (4 weeks))
研究者
Doosang Kim
Surgeon, M.D.,Ph.D.
Seoul Veterans Hospital