Written By: Joseph McFarland

As with many past stories of innovation, Intravascular Lithotripsy demonstrates the limitless possibilities when you put an engineer, a physician, and a businessman in the same room. This is a story of an unrelenting determination and the creative use of an existing technology that sends shockwaves to the world of calcified arteries.

The year was 2007. Daniel Hawkins, an accomplished businessman and inventor, was exploring alternative uses for existing technology in his role at a medical incubator. He stumbled upon lithotripsy, a technology mostly used for breaking down renal stones1. Lithotripsy began with the application of electrical current to produce sparks at the tip of a wire. These sparks swiftly vaporize fluid in the area, producing powerful pressure waves that travel at speed of sound to break up stones2. Daniel and his colleague John Adams, an electrical engineer known for his early work on pacemakers, were curious to discover other applications of that technique.

In Daniel’s weekly review of new patent filings, he read about a scoring balloon that claimed the ability to crack calcium in a vessel without disrupting healthy tissue2. A memory resurfaced, from a conversation during his earlier career, about how changing the compliance of a vessel could revolutionize the world of angioplasty1. Feeling that he might be on the cusp of discovering a game-changing innovation, Daniel asked John about the feasibility of placing a small electrical wire inside an angioplasty balloon. John was excited by the idea but recognized the challenge of delivering enough power to crack calcium, while not producing so much heat and pressure to pop the balloon. Nonetheless, he created an early prototype that they tested with success inside tiny drilled holes of toy chalk—replicating a calcified vessel. The idea of intravascular lithotripsy was born.

It was around this time that the team met Todd Brinton, an interventional cardiologist and director of Stanford’s Biodesign program2. Dr. Brinton had been investigating the treatment of calcified coronary arteries with cutting balloons prior to stenting1. He contributed valuable information to the team with his knowledge of current intravascular technology—affirming the need for a device that could effectively cross and dilate calcified lesions. With his clinical expertise, he encouraged them to make this technology as user friendly as the commonly practiced technique of angioplasty2.

Unfortunately, venture capitalists were not interested in their promising idea because of the economic difficulties of 20081. Despite the setback, this determined trio would not be stopped. They continued development out of John’s garage2. John began research on better surrogates for arterial calcium, only to discover that it had been in his backyard this entire time: eggshells from his wife’s chickens2. The eggshells shattered as expected, but they were much more excited by a finding they did not expect—the internal membrane of the egg was completely preserved2. Dr. Brinton was ecstatic as this membrane closely resembles the endothelium of a blood vessel. The team now had proof of concept.

With the generosity of friends and family, the team secured $300K to continue prototype development. They assessed the preclinical feasibility on diseased vessels of cadaver legs using intravascular ultrasound. These successful demonstrations were enough to attract several large investors, providing enough funding to progress to the first human study in New Zealand.

After years of hard work and successful clinical trials, the team obtained FDA approval and transformed the treatment of peripheral vascular disease in 2016. The team is never content as they expand this technology to all areas of the cardiovascular system2. Currently, they are seeking FDA approval for use in coronary vessels and assessing the technology for use in aortic stenosis2.

Sources:

1. Levin S. Shockwave Medical: Cracking the Calcium Code in Cardiology. The MedTech Strategist. 2015;2(14):30-37. Retrieved from https://www.sectoral.com/PDF/PE News/Shockwave_news_081215.pdf

2. Chalk, Organic Eggs & Cadaver Legs: IVL’s Journey from Idea to Reality. Shockwave Medical. https://shockwavemedical.com/technology/intravascular-lithotripsy-ivl/. Published September 9, 2019. Accessed August 27, 2020.