FDA clears Sonavex’s ultrasound blood flow monitor

Sonavex scored FDA clearance for its technology that uses ultrasound imaging and deep learning to deliver blood flow data on demand. The EchoSure system is cleared for use with the company’s EchoMark bioresorbable tissue markers, which got the agency’s nod in June. 

“The key goal is to be able to detect the problems associated with microvascular and vascular surgeries with high risk of post-op complications,” said Sonavex CEO David Narrow. A complication of microvascular surgery—used to reattach severed body parts such as fingers and hands by reconnecting tiny blood vessels and restoring circulation—is necrosis as a result of reduced blood flow and oxygen. 

The EchoSure device is designed to detect changes in blood flow to identify problems early. In the case of reconstructive surgery, it could detect a reduction in blood flow to reconstructed tissue before symptoms appear. 

“The gold standard for reconstructive surgery is to do a clinical exam of the reconstructive tissue to assess whether it’s starting to get colder, or bluer, or starting to appear to be in its early stages of necrosis,” Narrow said. “It’s basically waiting for the tissue to be almost dead to tell if there is a problem.” 

The Echomark tissue markers are implanted as a “backboard” for ultrasound waves, so the EchoSure device “knows where to look,” he said. The EchoSure device uses deep learning algorithms to derive where the ultrasound beam is coming from and then compute the volumetric flow rate through the vessels of interest so it can quantify the blood flow rate over time. 

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In addition to catching blood flow changes early, the system also makes ultrasound technology accessible to caregivers who do not have sonography training. There is also a mobile app for surgeons to monitor their patients remotely. This allows for more frequent monitoring—and more chances for intervention—as surgeons and nurses no longer need a trained sonographer to read the ultrasound and understand the blood flow data. 

The Johns Hopkins spinout will roll out the technology for reconstructive surgery first, before looking toward AV graft—an indirect connection between an artery and a vein, such as a plastic tube—and AV fistula—a direct connection between an artery and a vein. Both are used as points of access for hemodialysis. 

“We are currently ramping up our commercialization efforts and have just hired a new VP of sales, John Berry,” Narrow said. Notably, Berry has held the same position at TissueLink Medical, which became Salient Surgical, and was ultimately acquired by Medtronic for $525 million in 2011.