Study Finds Maquet Device Helps Reduce Risk of Coronary Artery Bypass Stroke

Risk of perioperative strokes may be minimized during coronary artery bypass graft (CABG) surgery by using a “clampless” technique consisting of off-pump coronary artery bypass (OPCAB) and Maquet Cardiovascular’s Heartstring Proximal Seal System, a clinical study has concluded.

The 1380-person study evaluated the incidence of post-operative stroke in people undergoing CABG while using the Heartstring device to maintain hemostasis during attachment of grafts to the aorta (proximal anastomosis). Prior to surgery, all patients underwent ultrasound evaluation of the aorta to determine the extent of aortic atherosclerosis. Increased aortic atherosclerosis is a powerful predictor of perioperative neurologic complications. In addition, other patient characteristics were used to calculate the expected risk of stroke for all patients using the Society of Thoracic Surgeons CABG Risk Model for Permanent Stroke. Across all aortic disease levels, the Heartstring device was associated with a 45 percent reduction in stroke risk compared with what would have been expected given patient risk factors.

“Surgeons constantly strive to prevent stroke during CABG surgery, and these data provide additional evidence to support the use of an off-pump technique and Heartstring when performing this life-saving procedure,” said Vinod Thourani, M.D., lead study author and associate professor of Cardiothoracic Surgery at Emory University in Atlanta, Ga.

The study examined the incidence of post-operative stroke in CABG using the Heartstring device in varying diseased aortas. These data were derived from a retrospective analysis of patients who underwent CABG with one or more proximal anastomoses constructed using the Heartstring technology at Emory University Hospital in Atlanta from April 2003 to December 2012. Patients had varying degrees of aortic atherosclerosis, ranging from mild (Grade 1) to very severe (Grade 5). Of the patients evaluated in the study, 92.5 percent underwent off-pump revascularization.

“Accumulating evidence points to the importance of eliminating the partial clamp in maximizing the potential benefits of off-pump surgery, particularly reduced stroke,” noted OPCAB expert John Puskas, M.D., associate chief of Cardiothoracic Surgery at Emory University. “The findings from our institution demonstrate the advantage of the Heartstring device in improving off-pump patient outcomes.”

While benefit of the device was most pronounced in patients with more severe aortic disease, significant reduction in stroke risk was seen in patients with minimal or no evidence of aortic atherosclerosis. Of particular note, no strokes were observed in a group of 59 patients with the most severe aortic disease (Grade 5). This group of patients is typically at extremely high risk of perioperative neurologic events.

“Aortic clamping may cause atheroembolism from the ascending aorta. Stroke is a devastating complication of CABG for patients and their families and can lead to significant, unexpected costs for hospitals,” said Peter Hinchliffe, president of Maquet Cardiac Systems. “We are proud to offer surgeons products that have the potential to reduce the risk of stroke significantly, enabling patients to recover and leave the hospital quickly, and most importantly, return to their normal lives as soon as possible.”

OPCAB has been associated with various benefits to patients, especially those at higher risk for complications. However, increasing evidence suggests that clamping and other types of mechanical manipulation of the ascending aorta during proximal anastomosis can reduce the potential benefits of OPCAB. During CABG, aortic manipulation causes atherosclerotic plaque to break loose and be transported as emboli to the brain via the bloodstream. These emboli are a recognized cause of neurologic injury and cognitive dysfunction. Although cannulation and cross clamping of the aorta are avoided during an OPCAB procedure, a separate clamp may be used to isolate a portion of the aorta from blood flow to allow the surgeon to attach the bypass graft. Maquet contends its Heartstring device eliminates the need for that additional clamp by providing a seal that prevents blood from entering the surgical field during construction of the proximal graft to the aorta.

OPCAB or “beating-heart” surgery is a form of CABG surgery performed without relying on cardiopulmonary bypass, or a heart-lung machine. During on-pump CABG surgery the heart is stopped and a heart-lung machine takes over the work of the heart and lungs to oxygenate the body. During OPCAB, the heart is still beating while the graft attachments are made to bypass a blockage. A specialized stabilizing device is used to keep the portion of the heart undergoing the bypass still while the surgeon sews the graft.

Maquet designs, develops and distributes innovative therapy solutions and infrastructure capabilities for high-acuity areas within the hospital including the operating room (OR), hybrid OR/cath lab and intensive care unit as well as intra and inter hospital patient transport. Headquartered in Rastatt, Germany, Maquet is the largest subsidiary of the publicly listed Getinge Group AB of Sweden. Maquet has 6,500 employees in 45 international sales and service organizations, as well as a network of more than 300 sales partners.