The Science Behind the Minnow Medical Peripheral Vascular System

The Minnow Medical Peripheral Vascular System was invented by biologists and biomedical engineers seeking an alternative therapy focused on accommodating unique characteristics of the peripheral arteries: twisting, turning, lengthening, and shortening of the arteries. Minnow combined the mechanical forces of a low-pressure, percutaneous angioplasty balloon catheter with the electrical forces of controlled, non-ablative, low-power radiofrequency (RF) energy to trigger a biological response that allows physicians to open stenoses to improve blood flow in a potentially durable manner via reshaping the arterial tissue.

Delivering a Better Response to Peripheral Arterial Disease (PAD)

Many current interventional therapies require the use of conventional balloon angioplasty either as a primary therapy or adjunct therapy. Typically, high pressure balloon inflations in the Superficial Femoral Artery (SFA) and popliteal arteries can cause dissection, resulting in secondary procedures that may include permanent implantation of a stent, which limits future therapeutic options. Moreover, angioplasty treated arteries show maintained luminal opening (patency) and improved blood flow only 33% of the time at 12 months following treatment. The use of stents as an adjunctive therapy to angioplasty results in greater success, although still limited.

Minnow strives to improve upon the success of balloon angioplasty and stents by inducing and maintaining artery patency in a cost-effective method through its Guided Reshaping Technology (GRT), which consists of a multi-use catheter that delivers a potentially durable treatment in a single endovascular procedure.

In contrast to balloon angioplasty, the Minnow catheter unblocks arteries without exposing them to high pressure balloon inflations, which can stretch and tear the artery walls, leading to dissection of the artery and inflammatory reactions at the cellular level. By using low-pressure inflations (2-6 ATM), the Minnow Medical Peripheral Vascular System may lessen arterial dissection and therefore reduce the immediate need for secondary, adjunctive therapy. Minnow scientists believe that the moderate heating of an atherosclerotic lesion causes plaque softening and reduction, or contracting of plaque volume, leading to an immediate luminal opening without overstretching and potentially tearing the artery, thus preventing vessel injury (barotrauma) and limiting an immune response which may lead to restenosis.

Lateral view of the Minnow Medical
Peripheral Vascular System.

As illustrated, a percutaneous angioplasty balloon catheter was developed with pairs of micro-thin electrode strips mounted lengthwise on a balloon catheter. The number of pairs of electrodes on the balloon corresponds to the diameter of the balloon (in millimeters). The current sizing of the Minnow catheter is 3mm, 4mm, 5mm and 6mm in diameter and 135cm in length.

Scientific Balance Shortens Procedure Time

Once the GRT catheter with its micro-thin electrode strips is placed at the site of the arterial plaque, the balloon is inflated at a low-pressure and a controlled, non-ablative, low-powered delivery of radiofrequency energy is delivered to the plaque site. The transmission time of RF energy can be varied to match the nature of the plaque. Typical treatment times are 10 seconds or less in total. This delivery of energy causes localized and moderate resistive heating within the plaque, triggering a biological response that immediately results in improved blood flow.

The theoretical mechanism by which the device operates is:

Denaturation - the radiofrequency energy creates resistive heating within the targeted plaque.  By controlling the power and duration of the radiofrequency (RF) energy, the temperature of the targeted tissue is raised to effective ranges, at which the hydrogen bonds in the plaque’s collagen molecules break. This results in a more compliant plaque that easily reshapes around the balloon catheter's open diameter, avoiding vessel stretching and injury.

Reduction – the denaturation of the collagen results in a reduction in the plaque volume, which results in a larger vessel lumen.

Duration - the application of the low-pressure, low-energy process stabilizes the treated artery in two ways:

1. Reduces neointimal hyperplasia by inhibiting smooth muscle cell (SMC) proliferation and consequent restenosis
2. Induces the death of inflammatory cells and macrophages as well as denatures inflammatory mediators, thus minimizing chronic inflammation.

Clinically Valuable and Viable

The procedure triggers a biological response that may permanently inactivate plaque so that it does not stimulate neointimal tissue formation, which leads to restenosis. Animal studies, conducted by the company and evaluated by board-certified histopathologists, have reported that treated arteries show increased lumen opening with minimal neointima and intact endothelium, all of which are sustained at 28 days. These factors may indicate that the long-term patency of a treated artery is achievable in patients with PAD.

Minnow Medical's Peripheral Vascular System is not for sale at this time. The claims for this device made on this website describe the expected clinical performance of the device and have not yet been confirmed through clinical trials.