At present, mitral heart valve failure is treated through invasive surgery or via a transcatheter procedure called Transcatheter Edge-to-Edge Repair (TEER). However, this procedure is difficult to perform, potentially resulting in suboptimal outcomes in challenging cases and if done by inexperienced clinicians.
To address this, Moray Medical, a company based in Mountain View, California, has developed a robotic catheter and associated technology, including augmented reality and a 3D digital interface, designed to make the job easier. In fact, the company claims that using its technology to deliver cardiac therapies can be as simple as moving a cursor on a computer screen.
The company hopes that its offerings will enable effective mitral heart valve repair outside of specialized centers of excellence, thereby expanding the number of patients who can avail of the treatment. Moray Medical was recently shortlisted for the MedTech Innovator, 2020 Grand Prize for its device.
Medgadget had the opportunity to talk to Mark Barrish, Co-Founder and CEO of Moray Medical about their technology, but first here’s a quick preview of how it works:
Conn Hastings, Medgadget: Please give us an overview of mitral heart valve failure. What is it, and who does it affect?
Mark Barrish, Moray Medical: The mitral valve is a high-pressure one-way valve between two of the chambers of the heart that allows blood from the lungs to be pumped in one direction and prevents reverse flow. Mitral valve failure (also called mitral incompetence or mitral regurgitation (MR)) is a failure of the mitral valve to close tightly when it should. When the heart squeezes to pump blood to the other muscles and organs, this failure results in blood flowing back toward the lungs. While many patients with mild MR remain asymptomatic for years, those with significant mitral regurgitation typically feel tired and out of breath, and the condition often progresses until it becomes debilitating and for far too many, fatal.
Two million people develop moderate to severe mitral regurgitation (MR class 3+) in the US each year. MR can occur at any age and acute MR can strike suddenly, but most patients develop symptomatic MR from other cardiovascular issues as they age. For example, if the heart chambers expand over time the valve leaflets—the tissue structures which engage against each other every heartbeat to prevent blood flowing backward—can gradually separate. In other patients the disease originates within the tissues of the valve itself, either due to infection or failure of individual valve components.
Medgadget: How is the condition typically treated? What are the challenges inherent in treating it?
Mark Barrish: Surgery treats only a small portion (less than about 2%) of MR patients. For example, if a young and otherwise healthy patient with acute MR is identified early, they may undergo open-heart surgery or robotically assisted laparoscopic surgery. For these surgeries the heart is stopped, the chamber is accessed through the heart wall, and the patient is supported by a heart-lung machine. The surgeon can then adjust valve tissues, attach support structures, or affix a replacement valve to the surrounding tissues of the heart. Surgical outcomes are highly skill dependent, and many MR patients are simply too frail to withstand the trauma these procedures impose on the heart and surrounding tissues.
Over the last decade a much less invasive option has become available. Rather than perforating the heart wall, a Transcatheter Edge-to-Edge Repair (TEER) implant or “clip” at the end of a flexible catheter shaft can be advanced through the vascular system into the heart. Using a series of mechanical actuators while viewing ultrasound and fluoroscopy images, the interventional cardiologist manipulates the clip within the heart to grasp the leaflets of the mitral valve adjacent the leak, permanently clipping a portion of the valve closed to prevent the backward flow of blood. TEER therapy is challenging to learn and perform, but a well-known 2018 COAPT study and data from almost 15,000 patents have shown that TEER provides advantages in morbidity, mortality, and quality of life, particularly when performed by experienced specialists (those who have performed more than 200 procedures and who are working at a large-volume TEER “center of excellence”).
In 2019, seven years after FDA approval, TEER therapy finally helped more MR patients than surgery. Unfortunately, most of those procedures were performed at small-volume centers by less experienced doctors. Because of the non-intuitive nature of the mechanical clip delivery system, the difficulty of interpreting the remote imaging, and the nuances of clipping differing valve anatomies, these small-center doctors simply do not achieve the same benefits for their patients as the centers of excellence.
Medgadget: Please give us an overview of the Moray Medical Robotic Catheter and associated technology, and how it can be used to treat mitral heart valve failure.
Mark Barrish: Moray Medical’s products will digitize the interface between the interventional cardiologist and their therapeutic tools, making it as easy to manipulate a clip inside the beating heart as it is to move a cursor across a computer screen. The Moray Clipper TEER implant is supported by a single-use catheter and advanced to the heart using standard interventional techniques. Once the Clipper implant enters the chamber bordering the mitral valve, the cardiologist mounts the catheter handle to a re-usable Moray Coral fluidic driver that is about the size and shape of a brick. The operator will then use Moray’s Submersion digital interactive environment—in which real-time off-the-shelf imaging is integrated into a 3D robotic workspace—to move the implant through the heart chamber to the valve leaflets. The user drives the implant by moving Moray’s Trident input device with one hand relative to the tissues shown in the Submersion display.
In response, the Coral driver changes the position and orientation of the implant with corresponding movements, facilitating alignment of the implant with the displayed tissues. Throughout this process the real-time tissue images are augmented with easily understood virtual images of the Clipper system to provide clear 3D situational awareness. The combination makes implementing movements of the clip almost trivial, freeing the operator to concentrate on the nuances of the hemodynamics and tissues of their patient. Once the Clipper implant is aligned with the leaflets of the mitral valve, the catheter remains in a fixed position so that the operator can manually engage the implant against the valve tissues and deploy the clip using the same tactile feedback as is provided by existing TEER implants.
Medgadget: How does the system compare with conventional equipment for percutaneous interventions in terms of complexity and ease of use?
Mark Barrish: The complexity of percutaneous interventional tools varies widely. Many of the interventional tools in common use are for stenting. These tools need to navigate within the branching coronary vasculature to gain alignment with a diseased segment of a lumen, where the stent can be expanded radially to engage and hold open the luminal wall. Decades of evolution in these tools have produced specialized guidewires and catheters that are refined, simple, and low in cost, and a large population of interventional cardiologists have developed impressive skills allowing them to quickly and reliably advance the tool shafts axially, rotating pre-bent ends into target luminal branches from outside the patient under the guidance of fluoroscopic imaging.
Structural heart specialists operate within the same broad interventional cardiology space but treat the valves and other tissue structures using tools that are often much more complex. For example, existing TEER therapies take advantage of standard interventional tools to access the vasculature and advance to the heart. However, TEER clips and other structural heart tools need to be aligned—in both position and orientation—with specific tissues bordering the open heart chambers. This is often much more challenging, and the mechanical systems now used to deliver these therapies are often much more complex.
In fact, disposable drive assemblies used by prior mechanical TEER systems have included well over 1000 unique mechanical components—which are all discarded after a single use. Moray maintains the simple and efficient access to the heart derived from stent therapies, but the fluid-driven single-use Moray Clipper TEER catheter has only 15 mechanical steering components, and even Moray’s re-usable Coral robotic fluid driver has less than 200 total components. The intuitive interaction provided by this robotic technology is also much easier to learn, more precise and repeatable, and will enable thousands of interventional cardiologists to treat the MR of millions of their patients.
Medgadget: Why are augmented reality and a 3D digital interface important in effectively using the catheter?
Mark Barrish: When the interventional cardiologist performs a robotic TEER therapy they cannot directly or optically see the valve tissues. Fluoroscopy provides a useful overall roadmap of the area, but the valve leaflets themselves are also not easily visible in those images. To grasp and clip these leaflet structures the operator needs to guide movement of the Clipper implant with reference to echocardiography (echo) images, typically bi-plane or 3D images from a Trans-Esophageal Echo (TEE) probe, a Trans-Thoracic Echo (TTE) probe, and/or an Intra-Coronary Echo (ICE) probe. Coordinating these different images from different sources at different orientations can be a challenge, particularly when trying to accurately position a clip in 3D despite differing views being shown in a side-by-side arrangement. The challenge can be even greater for interventional cardiologists who may have less experience interpreting multi-plane echo displays. Moray’s Submersion virtual reality environment helps overcome this challenge by aligning different real-time images in a coherent 3D robotic workspace that also contains a virtual model of the Moray Clipper robotic TEER system. Virtual images of the Clipper implant and its supporting catheter can be clearly and understandably projected onto the live image streams, helping the interventional cardiologist to know where the implant is relative to the defective valve tissue and how to move the implant efficiently and safely to exactly where he/she wants it.
Medgadget: How does the system affect procedure time and outcomes?
Mark Barrish: The precision, ease of use, and efficiency of Moray Medical’s Clipper robotic TEER therapy system have real benefits for patients, health care providers, and the private and public entities which pay for these therapies. The overarching benefit to patients will be the expanded availability of TEER therapy to treat their MR. Moray also expects our pivotal study to establish significant benefits in patient safety and efficacy in the small-volume centers that already perform the bulk of TEER procedures. The reduced learning curve and ease of maintaining proficiency provided by Moray’s robotic TEER therapy will benefit the clinical staff at regional hospitals and local cardiology groups, and will enable them to effectively treat their patients with MR, rather than having to refer them to distant (and often more expensive) centers of excellence. Patients, providers, and payors will all benefit from the significant reduction in average procedure times of robotic TEER. Perhaps even more important is the reduced variability in the time it takes to perform TEER therapies, which could allow each doctor to confidently schedule more procedures in a single day.