Mechanical Support for Heart and Lung Failure: Becoming the Standard of Care Is Your Practice Prepared?
STS News, Spring 2012 --
Margarita T. Camacho, MD • Immediate Past Chair, STS Workforce on Surgical Treatment of End-Stage Cardiopulmonary Disease
Mechanical circulatory support is a well-established therapy for advanced pulmonary and cardiac disease. Technological advances with smaller, more durable, and percutaneous approaches have expanded the availability of this technology for both temporary and long-term support options.
Shorter-term acute circulatory support has become more streamlined; emergently placed ventricular assist devices (VADs) and extracorporeal membrane oxygenator (ECMO) devices have become easier to implant and tend to be associated with less hemolysis and better overall outcomes.
Any operation, whether elective or emergent, can be complicated by failure to wean from bypass. Expeditious placement of a VAD or ECMO may provide the only chance for survival – and the recent advances in connection with these procedures makes this technology a must in any cardiac surgery program. Consider some actual cases that illustrate the importance of immediately available support:
- A 47-year-old male admitted in cardiogenic shock with tight left main stenosis, total occlusion LAD, no collaterals, underwent CABG x 3 and could not be weaned from bypass. LVAD inserted in less than 30 minutes and patient extubated, awaiting VAD explant or transfer to transplant center.
- A 55-year-old male admitted with acute aortic dissection and involvement of right coronary ostium, underwent repair of dissection. RV failure noted on intraop TEE and vein graft to RCA performed. Despite this, could not be weaned from bypass and RVAD placed in 20 minutes. Patient recovered fully; RVAD explanted five days later and patient discharged home.
- A 38-year-old female admitted in cardiogenic shock, unknown etiology, intubated with IABP. Despite maximum doses of inotropes and pressors, remained in profound shock with mean arterial pressure 45-55 and mixed venous O2 saturation in 40s. LVAD inserted off-pump, patient extubated the next day, out of bed POD #2, and LVAD explanted POD #5. Patient was discharged home the following week.
- A 17-year-old female with critical aortic stenosis underwent aortic valve replacement, could not be weaned from bypass. This center did not have an LVAD, only IABP. After four to five hours of bypass, an LVAD center was consulted and a team was sent with an LVAD to perform implant. This consumed approximately two additional hours of bypass time, since it was “after hours” and the visiting on-call team had to be mobilized. The implant proceeded well, but by this time, the patient had been on bypass eight to nine hours; she suffered significant coagulopathy and expired the following day. If the LVAD were immediately available, it might have been implanted after only three hours of bypass as a potential bridge to recovery or other treatment.
- A 65-year-old male underwent elective CABG x 3 and MVR, could not be weaned from bypass, center did not have an LVAD, only IABP. Another center was called after surgeon attempted to wean from bypass several times, and six hours of bypass had elapsed. By the time the visiting team arrived, almost eight hours of bypass had elapsed. Patient was in florid pulmonary edema and ECMO placed in less than 30 minutes. Although ECMO functioned well, he was very coagulopathic, edematous, anuric on CVVH, and expired two days later. Were an LVAD or ECMO immediately available, intervention could have occurred much earlier as a potential bridge to recovery or other intervention.
Patients like these can appear in any center in any city – and their chances of survival greatly increase with the immediate accessibility of the simpler and less traumatic devices available. For those patients who require longerterm support, the devices available are also smaller, more durable and associated with significantly better overall outcomes.
Proper planning is crucial to the success of any program with short- or long-term devices. Over the years, much has been learned about patient selection and patient/device management; a wealth of experience in these areas exists.