Hybrid Revascularization Strategy Driven by New Technology, and Soon, New Data

Reed Miller

January 31, 2011

January 31, 2011 (San Diego, California) — Hybrid procedures combining the best of bypass surgery and percutaneous intervention have been discussed as the next frontier in coronary revascularization for at least 10 years, but the momentum in favor of this approach may pick up steam as minimally invasive surgery technology has improved and a randomized trial is in the works.

"Right now, there are pioneers in the field pushing it forward, but I would argue that most surgeons in the country and in the audience are still doing conventional three-vessel bypass. They aren't looking at the hybrid," Dr James Fann (Stanford University, Stanford, CA) told heartwire after moderating a session on less invasive revascularization at the Society of Thoracic Surgeons (STS) 2011 Annual Meeting. "The surgical mode of thinking is that we're very conservative as a group. Most of us are going to wait for the data . . . and a vast majority of us are going to do what we've been doing."

Fann does not expect any single major randomized trial to suddenly motivate lots of hospitals to build hybrid revascularization operating rooms and combine surgical and interventionalist teams. Instead, interest will grow gradually as data trickle in from the accumulated experience of the handful of centers that are pioneering the approach. "There's not going to be a great prospective randomized trial on something like this. As we get more and more experience, we're going to see if the durability with this is borne out," Fann said.

The National Heart, Lung, and Blood Institute (NHLBI) recently launched an observational study planned for about 700 patients undergoing either hybrid revascularization or percutaneous coronary intervention. This study will then be followed by a randomized trial. The two studies will show which types of patients with complex coronary disease are best suited to the hybrid approach, according to Dr John Byrne (Vanderbilt University, TN) who presented on his center's extensive experience with hybrid procedures.

In Byrne's hybrid operating room at Vanderbilt, patients undergo minimally invasive bypass surgery to attach the left internal mammary artery (LIMA) to the left-anterior descending (LAD) artery, immediately followed by PCI in the other coronaries. "Increasing anatomic complexity, comorbidities, and the advanced age of our patients demand unique revascularization approaches," he said.

"Hybrid coronary revascularization combines the durability of [LIMA] coronary bypass with the minimal invasiveness and lower risk of percutaneous intervention," Byrne explained. "We know that a mammary to the LAD confirms long-term survival advantage, at least in part because it protects the proximal LAD territory against further ischemic injury from progressive disease. We also know that percutaneous intervention offers a less invasive means of revascularization and allows for rapid recovery with fewer short-term complications. This is preferred by patients and physicians."

He described his center's experience overcoming some of the challenges that flummoxed surgeons and interventionalists when they were first developing the hybrid procedure, such as how to manage patients' antiplatelet regimen to balance the bleeding risk during surgery with the thrombosis risk associated with stenting. His group gives patients 300 mg of clopidogrel before the procedure, followed by standard unfractionated heparin during the surgical revascularization and PCI, and then protamine reversal left to the discretion of surgeon. The patients continue with clopidogrel and aspirin in the ICU after their procedure.

Another advantage of the hybrid setup is that it allows the surgeon and the interventionalist to collaborate on the postprocedure arteriogram to inspect the results of both the bypass and intervention.

The creation of hybrid operating rooms staffed by teams of cooperative surgeons and interventionalists has sometimes been hindered by the professional rivalry between the specialties. But Byrne said that this is not an obstacle in his group. "Hybrid revascularization could bridge the divide in treatment philosophies and approaches that often exist between cardiologists and cardiac surgeons," he said. "We've seen that collaboration rather than competition benefits everyone--patients, hospitals, payers, and providers."

Fann said that many centers are creating or considering creating hybrid operating rooms as technology advances blur the distinction between surgery and PCI, not only in coronary revascularization, but other cardiac procedures--among the most important, transcatheter aortic-valve implantation.

Byrne pointed out that "interventionalists are becoming much more aggressive in treating patients who in the past have been the purview of surgeons," so surgeons need to be ready to work with interventionalists and catheter-based technologies. He expects to see the hybrid approach advance with continued improvement in minimally invasive robotic surgery devices and valve and stent technologies as well as the development of new "intrapericardial procedures" that could also be performed in conjunction with revascularization, such as atrial fibrillation ablation or left-atrial appendage ligation.

Fann stressed that the minimally invasive robotics technology, used for harvesting and connecting the LIMA bypass vessel, has advanced significantly in the past decade, allowing much better visualization and control than was ever possible with a minimally invasive surgical approach without the robot tools. "That's a large component of the technology leading the scope of our practice."

During the same session, Dr Johannes Bonnatti (University of Maryland, Baltimore) discussed his center's "pilot-copilot" approach to training surgeons on how to use the robotic tools. He said it took him 200 attempts at harvesting a LIMA with the robot, including simulation practices, to get his time from two and a half hours to below 20 minutes. However, the next generation of surgeons learning under him has been able to bring their times down much faster. With proper training and simulation, "this is worthwhile and can be taught and learned," he said.

Fann reports he is on NeoMend's consulting and advisory board.