Innovative Catheters For Safe and Precise Interventional Procedures

Patients

The Peripheral Artery Disease (PAD)

If you were diagnosed with infrainguinal PAD (Peripheral Artery Disease), you are suffering from narrowing or blocking of artery (“atherosclerosis”) in your leg/s. Atherosclerosis is caused by the buildup of fatty and fibrotic material (called atherosclerotic plaques) on the walls of the artery, which narrows the artery in the leg, and results in a diminished blood supply to your leg. The narrowing could become a blockage at certain places along the artery. The blocked segment of the artery is called a lesion. PAD patients are usually suffering from symptoms related to the lack of blood supply to the affected leg muscles as a result of the presence of this lesion inside their artery. It mainly manifests as diminished walking capability in which one has to stop walking from time to time until the muscles can recover and remove the lactic acid that accumulated from lack of oxygen. This walking impairment is called claudication. The blood pressure in the affected areas is also reduced.

Target population of PAD and main risk factors

The main risk factors contributing to PAD, may include (but are not limited to):

  • Male
  • Age > 65
  • Smokers
  • Diabetes mellitus
  • Hypercholesterolemia /hyperlipidemia
  • Hypertension
  • Obese (BMI>30)
  • History and/or family history of vascular disease (myocardial Infarction, stroke, PAD)
  • High levels of homocysteine and C-reactive protein (CRP)

PAD symptoms

If one or more of the symptoms below occur in your leg/s (or only in part/s of it: calves, buttocks, thighs, ankles, knees, hips, feet, toes) it may suggest that you are suffering from PAD. Many of the below symptoms may be present while resting and may worsen while walking a distance, exercising or climbing stairs:

  • Pain
  • Cramps
  • Stiffness
  • Aching
  • Numbness
  • Weakness
  • Coldness
  • Leg hair loss
  • Color change
  • Wounds and ulcers
  • Muscle/tissue loss
  • Gangrene

Diagnosis methods for PAD

PAD patients may be asked to undergo the (mostly non-invasive) common tests below to diagnose their disease and its staging, and to allow for repeated objective measurements over time to detect improvement or deterioration of their PAD, or to confirm that a revascularization (procedure done to restore the blood supply to their leg) was successful.

These tests / examinations may include (but are not limited to):

Physical examination
Patient’s legs and feet are examined by the doctor while fully exposed to detect any changes in skin color and texture (thin and shiny skin, hair loss and trophic skin changes, tissue loss, ulceration and gangrene, skin pallor), and blood flow indicators are externally examined - decreased blood pressure or pulse absence / irregularities, in the leg.

Blood Tests
Patient’s blood tests help indicate the risk factors for PAD development (lipid profile, cholesterol, coagulation tests). It can also detect blood indicators for organ injury or the worsening of peripheral blood supply by measuring levels of homocysteine (the building blocks for proteins), and C-reactive protein (CRP) (produced by the body in response to inflammation); when both of these are present in high levels in the blood this can be associated with atherosclerosis.

ABI/TBI (Ankle/Toe-Brachial Pressure Index)
This is a common, non-invasive test with high sensitivity and specificity in identifying healthy individuals or those diagnosed with PAD, if the result of the ABI exceeds the normal ranges. ABI is the ratio calculated from the blood pressure measured by an inflated cuff placed on the patients’ ankle/toe and compared to the blood pressure measured with by an inflated cuff placed on the patients’ arm.

DUS (Duplex ultrasonography)
This is a common, non-invasive ultrasound imaging of the leg suspected with PAD. This imaging approach shows blood vessels structure with blood flow and allows estimation of the vessel diameter and level and velocity of blood flow. DUS is a useful tool to define the locations of lesions/blockages in the artery.

Angiography
A minimally-invasive examination done by injection of contrast agents into the artery via a catheter inserted at the groin area with X-rays (fluoroscopy) imaging. This allows for viewing the blood flow up from the common femoral artery to the artery in question with the specific blockage, and downstream until the foot. Although fluoroscopy by X-ray is the most used imaging method for PAD angiography, the doctor may use other imaging modalities prior to the invasive angiography, such as Computerized Tomography Angiography (CTA) or Magnetic Resonance Angiography (MRA), which are both non-invasive. If invasive diagnosis is used it enables the physician to treat the lesion in the same session.

Walking Impairment Questionnaire (WIQ)
This questionnaire is a validated subjective tool to detect changes in the daily walking ability of PAD patients. This questionnaire is filled out by the patient and evaluates the patient’s walking ability, with a focus on walking distance, walking speed and the ability to climb stairs.

Rutherford Classification
A commonly used clinical staging system for describing PAD, this can be used as an objective scale to allow doctors to describe and discuss PAD patients using a common terminology. It has seven stages, from Stage 0 (asymptomatic) to Stage 6 (severe ischemic ulcers or gangrene).

Treatment options

If conservative treatments, including medications, do not relieve your claudication, an invasive approach will be taken, as follows.

Angioplasty
As first approach for treatment, PAD patients may routinely be referred to interventional physicians, which will try to restore the blood supply to the diseased artery by a minimally invasive procedure. The angioplasty ("repair of a blood vessel") is done by first accessing the artery at the groin area. Then, the physician passes the lesion with a very narrow metal wire called "guide wire", and once in place, a balloon catheter is advanced over the guide wire, all the way to the lesion in the artery. Once positioned inside the lesion, it is inflated to push and press the plaque into the vessel wall, to open the narrowed artery. The balloon is deflated and removed from the body, and sometimes is followed by an implantation of a metallic stent (expandable small metallic scaffold) inside the lesion that maintain it open longer-term.

Atherectomy
Atherectomy is a minimally invasive procedure used to treat PAD in which a catheter, called an atherectomy catheter or atherectomy device, is inserted the same way as described above over the guide wire until reaching just before the lesion, where it is then activated to remove portions of plaque. The atherectomy technique cuts or vaporizes portions of the plaque from the wall of the artery. Once this step is done, a balloon is inserted over the guide wire as described above, but this time there is less material of plaque to be pressed against the artery wall, which usually helps to maintain the artery open for a longer time than just using the balloon without atherectomy. Sometimes the balloon action is followed by implantation of a metallic stent (expandable metallic scaffold) implantation to allow further support.

Amputation
Once the PAD symptoms are present and cannot be treated with angioplasty (or angioplasty with atherectomy), the disease can progress and worsen to an unwanted progressing stage, called critical limb ischemia (CLI). In CLI the patient suffers significant pain in the leg (even is rest), and non-healing wounds, ulcers, extensive infections or even gangrene (tissue death) may develop in the affected leg or foot. Amputation - surgical removal of the affected leg or part of it (toe/s, foot, etc.) - may be necessary at this stage of the disease.

Surgical Bypass
Usually if the angioplasty (or angioplasty and atherectomy) attempts fail to improve sufficient  blood flow, a bypass surgery by a vascular surgeon is done. The bypass (made of a vein or a synthetic tube) connects the vessel area above the treatment-proofed lesion to a vessel area below it, to create an alternative path for blood flow around this treatment-proof lesion.

The B-Laser™ atherectomy technology

The FDA cleared and CE certified B-Laser™ device's intended use and indication  for use is similar to other approved atherectomy devices. Howvere, it is most innovative and has several differences compared to other  devices. It is made of an array of optic fibers (to transfer laser energy) that are surrounded and supported by a circumferential blunt blade (for mechanical support and to complete the laser first cut). The catheter, which is made of known materials that are widely used in medical devices, is supplied sterile and intended for single use only. The B-Laser™ device performs partial removal of the lesion inside the artery, to improve the results of subsequent balloon angioplasty or stent placement in opening the blocked artery. Effective restoration of adequate blood supply is expected to decrease the pain in the leg.

The B-Laser™ solution- a single catheter that effectively treats all types of PAD lesions:

  • Lesions inside stents
  • Chronic total occlusions – defined as complete (100%) blockage of the artery
  • Lesions with severe calcification
  • Lesions which are made of thrombus (blood clots that blocks the artery)
  • Lesions that are made of fibrotic and soft plaque
  • Lesions located above the knee
  • Lesions located below the knee and below the ankle

B-Laser™ bears the CE Mark and is FDA cleared.
B-Laser™ procedure duration is similar or less than the other non-surgical procedures to treat PAD.

Clinical experience with B-Laser™

The B-Laser™ catheter has already been used to treat successfully 50 PAD patients who participated in a European clinical study between October 2015 and July 2017, and additional 97 patients in an IDE study in the USA and EU.

Potential PAD procedure complications

Potential side effects and complications, which are not specifically related to B-Laser™ and may accrue in ANY PAD intervention procedure, may include (but are not limited to):

  • Fever, vomiting, signs of nausea as a result of using anesthetic medicines
  • Allergic reaction from the contrast media used for the X-ray that is used in such procedures
  • Distal embolization
  • Bleeding or bruising at catheter’s insertion point
  • Pain, infection, fever, extremities pain
  • Arterial dissection
  • Ischemia due to restenosis of the dilated segment
  • Cardiovascular related death
  • Arterial perforation
  • Vessel trauma
  • Amputation at any level
  • Hematoma
  • Pseudoaneurysm
  • Occlusion of a peripheral artery branch
  • Prolonged procedure time
  • Deterioration of kidney function/kidney failure from usage of X-ray contrast media
  • Skin trauma due to X-radiation
  • Any other known complication in such procedures

Potential benefits

Treatment with B-Laser™ may relieve the patient's PAD symptoms such as leg pain and may improve the walking ability and quality of life. It also may help reduce the chance of side effects during any PAD procedures (described above) as well as reducing the chance that the treated lesion will be blocked again (although these outcomes cannot be promised).