BIOPROSTHETIC AORTIC SCALLOP INTENTIONAL LACERATION TO PREVENT IATROGENIC CORONARY ARTERY OBSTRUCTION| BASILICA
An innovative catheter technique is helping to transform treatment for patients whose bioprosthetic aortic valve is failing. The BASILICA procedure, developed in part by MedStar Heart & Vascular Institute’s Toby Rogers, MD, PhD, prevents one of the most feared, and often fatal, complications of valve-in-valve TAVR— coronary artery obstruction caused by mechanical displacement of the old valve’s leaflets.
BASILICA (Bioprosthetic Aortic Scallop Intentional Laceration to prevent Iatrogenic Coronary Artery) obstruction employs an electrified guide-wire threaded through a catheter to slice the leaflet of the patient’s failing bio-prosthetic valve. Cutting the leaflet before TAVR allows blood to flow into the coronary artery through the split leaflet when the new valve is deployed.
DECREASING RISK OF A FATAL COMPLICATION
“Surgical tissue heart valves can become narrowed and leaky over time,” explains Dr. Rogers. “A second surgery to replace a failing valve is usually much higher risk for patients than their original surgery. For many patients, TAVR is a lower-risk alternative. But as a community we have learned the hard way that in some patients, displacing the leaflets of the original valve to make room for the new valve can block off a coronary artery,” he says.
“As younger and younger patients receive bioprosthetic rather than mechanical surgical valves, and with bioprosthetic valves expected to last 10 to 15 years, many patients in the future will require a re-do procedure,” Dr. Rogers explains. “They may want to have TAVR, but we have found that a small but significant minority are at high risk of coronary artery obstruction due to the type of surgical valve they have, and their own anatomy."
“We know from large registries that if coronary artery occlusion occurs, more than 50 percent of these patients will die. With BASILICA, we now have a reliable percutaneous treatment option to offer,” he says.
Before the development of BASILICA, the only alternative for these patients was deploying a stent in the ostium of the threatened artery to hold the leaflet away as the TAVR valve was deployed. “But this was a short-term solution with a number of complications,” Dr. Rogers adds.
Dr. Rogers was part of the team at the National Heart, Lung and Blood Institute (NHLBI) that conducted the animal research leading to the BASILICA procedure. The first-in-man BASILICA procedure was performed at the University of Washington in the summer of 2017 with Dr. Rogers in attendance. To date, more than 25 BASILICA procedures have been performed worldwide.
CRITICAL CLINICAL TRIAL AT MHVI
Late last year, Dr. Rogers performed the BASILICA procedure on a patient at MedStar Washington Hospital Center with excellent results. “The patient we treated was very sick with a failing surgical bioprosthetic aortic valve that was leaking severely and causing heart failure,” Dr. Rogers says. “Another surgery was not an option as she was just too unwell. Her CT scan showed that she was at risk of coronary artery obstruction. We performed the BASILICA procedure, which was a success, and the patient was discharged just a few days later."
“We believe we can predict fairly well through multimodality imaging who is at risk for this potentially fatal complication,” he says. “But we would like to gather additional data from a larger patient population. This is why we initiated the BASILICA clinical trial, an FDA-approved Early Feasibility Study sponsored by the NHLBI. The Hospital Center is one of just five medical centers in the U.S. participating.”
“The BASILICA procedure is part of a family of transcatheter electrosurgery techniques we developed at NHLBI,” Dr. Rogers says. “These techniques are being applied to other structural heart interventions, including as a way to prevent left ventricular outflow tract obstruction during transcatheter mitral valve replacement, and for transcaval access in patients uneligible for transfemoral access by TAVR due to peripheral artery disease. Our objective is to develop solutions for patients unable to have standard treatments due to their complex anatomy and comorbidities.”
Early Feasibility Study
FIRST-IN-MAN TRANSCAVAL TAVR PROCEDURE USING NEW CLOSURE DEVICE
Transcaval access has become the preferred alternate access approach at MedStar Washington Hospital Center for patients who are ineligible for transfemoral TAVR due to small or diseased iliofemoral arteries. Until now, closure of the transcaval access was performed using cardiac occluder devices that were not designed for this purpose. The Hospital Center is participating in the first FDA-approved Early Feasibility Study (EFS) of a new dedicated closure device for transcaval TAVR, sponsored by the National Heart, Lung and Blood Institute. Toby Rogers, MD, performed the first-in-man transcaval TAVR procedure using this new device in February 2018. The hospital has enrolled seven patients into the study thus far, and early results have been very promising. The full results of the EFS will be presented later this year.
CORONARY OBSTRUCTION AND PREVENTION BY BASILICA
After valve-in-valve TAVR in patients with large aortic root, blood can flow around the old valve to reach the coronary arteries. In some patients with small aortic root and low-lying coronary arteries, the leaflets of the failing surgical bioprosthetic valve can obstruct blood flow to the coronary arteries. BASILICA enables coronary blood flow in these patients by splitting the leaflet of the failing bioprosthetic valve immediately before TAVR.