Cardiac Surgery Featuring INVOS Cerebral Oximeter Broadcast Live to Surgeons, Announces Somanetics.

Business Editors, Health & Medical Writers

TROY, Mich.--(BW HealthWire)--Feb. 7, 2002

A live satellite transmission of a patient undergoing coronary artery bypass graft surgery with the "off-pump" beating-heart technique and monitored with Somanetics' INVOS(R) Cerebral Oximeter was broadcast to approximately one thousand cardiothoracic and vascular surgeons attending the Cardiothoracic Techniques and Technologies international symposium in Hallandale Beach, Fla., announced Somanetics Corporation (Nasdaq:SMTS).

The surgery was performed by Yvon Baribeau, M.D., cardiac surgeon, Catholic Medical Center, Manchester N.H., at the medical center and transmitted to the symposium, allowing participants to interact with the surgical team. The purpose of the symposium is to update attending physicians to new developments in cardiothoracic surgical techniques and technologies.

The off-pump technique for coronary artery bypass and grafting eliminates the need to place patients on the traditionally used heart-lung machine. The heart-lung machine, currently used for the vast majority of all bypass procedures, has recently come under scrutiny for being a potential primary cause of many adverse post-operative outcomes associated with the traditional methods of bypass. These range from clinical stroke to potential subtle neurocognitive changes.

Beating-heart surgery can be associated with significant blood pressure changes during heart mobilization and stabilization. Large fluctuations in blood pressure can reduce organ blood flow, potentially causing brain damage, kidney failure, and various other poor outcomes. These fluctuations can be common using the off-pump technique. With the INVOS system, the surgeon is able to assess the patient's ability to tolerate such fluctuations and, if needed, the surgeon can intervene and greatly reduce the chance of inadequate cerebral blood flow.

The 62-year-old male cardiac surgery patient was monitored with Somanetics' INVOS Cerebral Oximeter. This "window to the brain" system continuously monitors changes in the regional oxygenation of the blood in the patient's brain by transmitting and detecting visible and near-infrared light through SomaSensors(R), single-use sensors that are noninvasively (no needles or risk of associated infection) placed on both sides of a patient's forehead.

If a patient experiences a significant decline in brain blood oxygenation the medical team can adjust medications, adjust blood pressure or make other physiologic changes to correct the low brain blood oxygenation.

"The brain is what it's all about, and for my practice the INVOS Cerebral Oximeter is a standard of care for beating-heart surgery," says Dr. Baribeau. "The gross operative risk of stroke can be largely reduced through carotid screening and epiaortic ultrasound and the majority of our strokes are now postoperative in our practice. Still, the more subtle neurocognitive changes are the focus of attention. By staying within 20 percent of the baseline saturation at the time of heart positioning, we can tolerate a lower pressure than we normally would, and since these periods are fairly short, the pharmacological interventions by the anesthesiologist and secondary blood pressure swings are less. This makes the operation smoother for all of us, patient, anesthesiologist and surgeon," he says.

"By monitoring the patient's brain blood oxygen levels with the INVOS monitor, I can be satisfied that my patient can tolerate these blood pressure changes. If the patient's blood pressure decreases and brain blood oxygen saturation does not significantly change, I know the brain is being adequately perfused. On the other hand, if brain blood oxygen saturation declines, the monitoring system is my guide to determine if I need to change my technique, such as alter drugs, reposition the heart, or go on the bypass machine," says Dr. Baribeau.

"The worst complication of heart surgery is permanent brain damage, from subtle changes to frank clinical stroke. Monitoring the patient's brain blood oxygen allows us to work calmly in a controlled situation, whether we are using the off-pump or on-pump bypass technique. In addition, the occasional period of controlled hypotension during beating-heart surgery is so short that I don't worry about the other organs, either, as long as I stay within 20 percent of baseline saturation. The exception is patients with elevated creatinine or known mesenteric vascular disease, in which case we will not compromise and will keep the pressure up," he says.

Somanetics Corporation, headquartered in Troy, Mich., manufactures and markets the INVOS Cerebral Oximeter patient brain blood oxygen monitoring system, the only noninvasive and continuous monitor of changes in regional oxygen saturation of a patient's blood in the brain commercially available in the U.S. Use of the patient monitoring system can help medical professionals, including surgeons and anesthesiologists, identify regional blood oxygen imbalances and take corrective action. Such action can potentially prevent or reduce neurological injuries related to adverse events during surgery or in the critical care unit and reduce the associated cost of care.

Somanetics also markets the CorRestore(TM) System for use in cardiac repair and reconstruction, including a procedure called Surgical Ventricular Restoration, or SVR, a treatment for patients with certain types of congestive heart failure.

Somanetics' web site address is www.somanetics.net.