Technology

Sonic Lumen Tomography Intravascular Ultrasound (SLT IVUSTM)

Provisio Medical is pioneering a novel application of intravascular ultrasound (IVUS) for sizing and assessing vessels in cardiovascular procedures called Sonic Lumen Tomography (SLT IVUS). SLT IVUS uses sound to render highly accurate measurements of the blood flow lumen of vessels —information that is essential for assessing clinical presentation, guiding treatment decisions such as proper sizing of therapeutic endovascular devices, and confirming treatment strategies.

New Technology

SLT IVUS provides real-time measurements of a vessel’s flow lumen without the need for user interpretation. The SLT IVUS technology utilizes proprietary sensors that are designed specifically for integration into the type of endovascular catheters that physicians are already using, eliminating the need for an additional procedure. The SLT IVUS disposable components are also designed to be cost efficient and highly manufacturable, allowing for very attractive pricing versus conventional imaging-only catheters. The SLT System can be easily integrated to any Office Based Lab (OBL) / Office Interventional Suite (OIS), catheterization lab, or hybrid operating room.

With integration compatibility into support, PTCA, PTA, stent delivery, transcatheter valve delivery, drug-eluting balloon, and other endovascular catheters and devices, Provisio’s platform SLT technology could represent a disruptive technology across the peripheral vascular, coronary, neurovascular, and structural heart markets.

Sonar

Sonar (sound navigation and ranging) has extensive marine applications. By sending out pulses of sound or ultrasound and measuring the time required for the pulses to reflect off a distant object and return to the source, the location of that object can be ascertained and its motion tracked.

This technique is used extensively to locate and track submarines at sea and to locate explosive mines below the surface of the water. Source: https://www.britannica.com/science/ultrasonics/Ranging-and-navigating#ref527474

Shortcomings of Current Endovascular Sizing Methods

Sizing Matters!

Endovascular procedures require accurate vessel sizing for optimal clinical outcomes. The predominate method used exclusively more than 90% of the time to size vessels during endovascular therapies is fluoroscopy, an X-ray-based technology that utilizes ionizing radiation and kidney-toxic contrast media to display a low-resolution 2D view of the lumen of vessels. Fluoroscopy is also commonly referred to as an angiogram or venogram depending on which vessels are being assessed. As today’s standard of care, fluoroscopy falls short of enabling accurate vessel sizing, especially in the peripheral vasculature. To a far lesser degree, endovascular imaging technologies such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are available as higher-resolution alternative methods utilized to size vessels.

Fluoroscopy is mandated for most endovascular procedures, often with contrast to observe flow characteristics(1,2). Historically, digital subtraction angiography (DSA) as an enhancement to classical fluoroscopy has been considered the standard of care for vessel sizing and treatment. However, this modality is limited to providing a low-resolution, two-dimensional image of an often complex three-dimensional luminal structure. Thus, common consensus is that physicians often underestimate the vessel size with fluoroscopic guidance(3,4).

Intravascular Ultrasound – IVUS provides an intra-luminal perspective for both arterial and venous interventions. IVUS helps physicians define intravascular lesions to guide appropriate stent sizing and placement and its use has resulted in better procedural outcomes(5). IVUS appears to offer a greater degree of accuracy in measuring arterial lumen diameter. As measurements obtained from angiographic imaging consistently under-estimated vessel size, utilization of IVUS may aid in the determination of treatment algorithms and lead to improved endovascular outcomes(1). Sizing vessels with IVUS, however, requires a physician to interpret low resolution, grainy, grayscale images. Despite its advantage over fluoroscopy, traditional IVUS is estimated to be utilized in less than 5% of peripheral endovascular procedures(7,8,9). The common objections of IVUS use are: 1) an additional procedure is required, 2) additional time, 3) incremental cost and 4) complex and difficult image interpretation.

Optical Coherence Tomography – OCT is another intravascular imaging modality that was developed for its high-resolution capabilities. The resolution of OCT is more than 10 to 100 times finer than standard clinical ultrasound and can image up to 2 to 3 mm deep in most tissues(6). Despite these advantages, OCT requires flushing of the blood from the vessel in order to image it which adds complexity to workflows. Currently, OCT catheters are only indicated for coronary arteries; however, OCT technology has been integrated into a family of peripheral atherectomy devices.

With the introduction of Sonic Lumen Tomography, a sonar-based intravascular ultrasound technology, we aim to offer a solution with significant advantages to overcome the shortcomings of other sizing methods. SLT IVUS will provide real-time dimensions of the flow lumen of vessels without the need for physician interpretation and without disruption to their workflows.

Angiogram / Venogram

An angiogram is an X-ray procedure that can be both diagnostic and therapeutic. It is considered the standard for evaluating blockages in the arterial system. An angiogram detects blockages using X-rays take during the injection of a contrast agent (iodine dye).

https://vascular.org/patient-resources/vascular-tests/angiogram

Intravascular Ultrasound – IVUS

A miniature ultrasound-mounted catheter that is connected to an electronics console to reconstruct the images transmitted by sound waves.  The ultrasound signal is produced by passing an electrical current through the piezoelectric (pressure-electric) crystalline
material of the transducer that expands and
contracts when electrically excited.

https://emedicine.medscape.com/article/1839639-overview#showall

Optical Coherence Tomography

OCT is analogous to ultrasound imaging, except that it uses light instead of sound. OCT can provide cross sectional images of tissue structure on the micron scale in situ and in real time.

Fujimoto JG, Pitris C, Boppart SA, Brezinski ME. Optical coherence tomography: an emerging technology for biomedical imaging and optical biopsy. Neoplasia. 2000;2(1-2):9-25. doi:10.1038/sj.neo.7900071

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1531864/

  1. https://www.fda.gov/radiation-emitting-products/medical-x-ray-imaging/fluoroscopy
  2. https://www.fda.gov/radiation-emitting-products/medical-imaging/medical-x-ray-imaging
  3. Pliagas G, Saab F, Stavroulakis K, Bisdas T, Finton S, Heaney C, McGoff T, Hardy K, Adams G, Mustapha JA. Intravascular Ultrasound Imaging Versus Digital Subtraction Angiography in Patients with Peripheral Vascular Disease. J Invasive Cardiol. 2020 Mar;32(3):99-103. PMID: 32123141.
  4. Steven E. Nissen. Circulation. Intravascular Ultrasound , Volume: 103, Issue: 4, Pages: 604-616, DOI: (10.1161/01.CIR.103.4.604)
  5. https://www.acc.org/latest-in-cardiology/articles/2020/07/01/12/42/ivus-guided-peripheral-vascular-intervention
  6. Fujimoto JG, Pitris C, Boppart SA, Brezinski ME. Optical coherence tomography: an emerging technology for biomedical imaging and optical biopsy. Neoplasia. 2000;2(1-2):9-25. doi:10.1038/sj.neo.7900071 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1531864/
  7. iData – U.S. Market Report Suite for Peripheral Vascular Devices – USPV18_MS
  8. MRG – Peripheral Vascular Devices – Medtech 360 – Market Insights – US – 2021 – M360PV0068
  9. Internal company estimates