Jonathan D. Leff

Left Ventricular Assist Devices: An Evolving State of the Art

Heart failure is a disease of increasing prevalence around the world. The treatment options for patients suffering from this ailment range from pharmacologic to surgical. Heart failure, however, continues to harbor a dismal prognosis despite conventional treatments. The high mortality rate among this patient population has spawned interest in alternative therapies. Mechanical circulatory support has emerged as a treatment option for patients with refractory heart failure. Over the past years a number of studies have highlighted the effectiveness of left ventricular assist devices (LVAD’s) in improving patient’s outcomes. The technologies that support these devices have evolved and provide new opportunities to manage patients suffering from this debilitating disease. Heart transplantation continues to generate the most reproducible survival benefit to patients with advanced heart failure, but is limited by a lack of donors. It is therefore the goal of mechanical assist therapy to improve patient survival and quality of life in heart failure in light of the limitations of heart transplantation. In this article we examine the evolving utility of LVAD’s in the treatment of heart failure.

Robotic-assisted cardiac surgery

Historically, cardiac surgery has relied on thoracotomies and median sternotomies for access to the heart. Over the last decade, this approach has been challenged and innovative new techniques have emerged to provide alternatives to the standard sternotomy. Currently, the da Vinci surgical system (Intuitive Surgical, Sunnyvale, CA) is used at a number of hospitals in the United States and around the world in cardiac surgery. The technology allows for “wrist-like” instrument articulation, which provides greater freedom of movement and suppression of tremor to impart excellent surgical outcomes (Fig. 1). These benefits include less pain, shorter hospital stays, faster recovery, and improved cosmesis. Currently, over 1700 cardiac operations are performed each year in the United States using the da Vinci surgical system, and the number of cases is increasing by approximately 25% per year. Not all cardiac surgeons have shared in the enthusiasm and it has been pointed out that the increase in cardiac robotic surgery occurs in only a handful of institutions. A large number of programs that had at one time used the robot for cardiac surgery have abandoned this technique for other treatment strategies. In this chapter, we will provide a review of robotic surgery and present the current and possible future utilizations of this technology in cardiac surgery.

Novel approach for heart failure treatment after liver transplantation

Cardiac dysfunction is a well-known, poorly understood multifactorial condition among patients with cirrhosis. There are only limited data available describing the new onset of congestive heart failure (CHF) after liver transplantation (LT). The therapeutic modalities for treatment of this serious posttransplant complication are also not well defined. We would like to report our unique experience with the successful use of a biventricular assist device (BIVAD) in the treatment of post-LT CHF. A 46-year-old female with a past medical history of end-stage liver disease secondary to alpha-1antitrypsin deficiency (heterozygous), hepatic encephalopathy, ascites, esophageal varices, emphysema, and portal vein thrombosis with cavernous transformation was scheduled for LT. Her condition was complicated by the development of hepatorenal syndrome, which required continuous venovenous hemodialysis (CVVH). Her preoperative laboratory results were remarkable for hemoglobin, 9.9 g/dL; platelets, 22,000/ll; international normalized ratio, 1.8; partial thromboplastin time, 44.3 seconds; prothrombin time, 17.9 seconds; creatinine, 1.6 mg/dL; total bilirubin, 8.5 mg/dL. The preoperative stress test showed an ejection fraction (EF) of 55%, normal left and right ventricular function, intrapulmonary shunt, and pulmonary artery systolic pressure 30 mm Hg. Taking into consideration the need for decompression of the portal venous system, the LT proceeded with the use of venovenous bypass. The outflow cannulas were placed into a femoral vein and inferior mesenteric vein, and the return cannula was placed into an axillary vein. A 2-L bypass flow was achieved. During the surgical procedure, the patient received 10 units of packed red blood cells, 6 L of crystalloids, 4 units of fresh frozen plasma, 3 units of platelets, and 1 L of 5% albumin. The bypass time was 180 minutes. An intraoperative transesophageal echocardiogram showed stable cardiac function with preserved EF during entire surgical procedure. Postoperatively the allograft function was normal. The patient required CVVH for 2 days without additional vasopressor support and was extubated on day 3 after surgery. On day 5, she suddenly developed atrial fibrillation with rapid ventricular response and was placed on amiodarone infusion. On day 7 after LT, the patient became significantly hemodynamically unstable and required multiple vasopressors. A repeated echocardiogram showed an EF of 10%, biventricular dysfunction, and moderate to severe mitral regurgitation (Fig. 1). The patient did not improve and on postoperative day 8, the patient was placed on a venoarterial extracorporeal membrane oxygenation (ECMO) device. After 10 days of ECMO support, the patient did not show any signs of recovery. Echocardiograms revealed persistent severe biventricular dysfunction and mitral regurgitation. Following a discussion with the family and cardiothoracic surgeons, the patient was offered a BIVAD. On day 18, she underwent Centrimag BIVAD placement. One week after this lifesaving procedure, BIVAD was turned down, and the echocardiogram showed a full recovery of both ventricles and an EF of 60% (Fig. 2). According to the literature, posttransplant cardiomyopathy has been reported to have an incidence ranging from approximately 3% to 7%. The etiology of postoperative heart failure following LT is varied and includes ischemic, nonischemic, valvular, hypertensive heart disease, alcoholic heart disease, tachycardia-induced, or of unclear origin. The prevalence of specific etiologies has not thoroughly been studied, with the data being largely retrospective, and varies with the interval of postoperative time examined. The risk factors associated with postoperative heart failure after LT are also numerous and varied. In a study published in 2013, Qureshi et al. reported low preoperative mean arterial pressure, pulmonary hypertension, diastolic dysfunction, and extremes of blood pressure (mean arterial pressure<65 mm Hg or blood pressure>145 mm Hg) were associated with post-LT heart failure leading to almost twice as high all-cause mortality. In our case, the cause of the myocardial dysfunction is unclear. The preoperative systolic function was not significantly abnormal and no diastolic dysfunction was noted on echocardiographic studies. It is possible

CASE 2—2016 Complete Failure of Mechanical Mitral Valve Opening on Weaning From Cardiopulmonary Bypass

From the *Department of Anesthesiology, Rush University Medical Center, Chicago, IL; †Department of Anesthesia and Critical Care, University of Chicago Medical Center, Chicago, IL; ‡Hospital of the University of Pennsylvania, Philadelphia, PA; and §Department of Anesthesiology Montefiore Medical Center, Bronx, NY. Address reprint requests to Kimberly L. Kesner, MD, Department of Anesthesiology, Rush University Medical Center, 1653 W. Congress Parkway, #739, Chicago, IL 60637. E-mail: kim.taub@gmail.com

Pre-operative Risk Stratification Update for Cardiac and Major Vascular Surgery

Pre-operative risk stratification of patients for cardiac and major vascular procedures remains an evolving process. There are several models that generate risk scores and estimate post-operative morbidity and mortality outcomes. In addition to predicting outcomes, risk stratification can guide the need for further perioperative investigations and also assist in providing individualized therapy. An ideal model for risk stratification is one with not only good validity but is also reproducible. The risk stratification system needs to be applicable across diverse patient populations and hospital practice. In this article, we review various pre-operative risk stratification models and access their usefulness for cardiac and major vascular surgery.

Intraoperative Epicardial Ultrasound Probe for Visualization of Embedded Coronary Arteries A Novel Approach

The identification of coronary anatomy at the time of cardiac revascularization can be problematic. Preoperative studies (ie, coronary angiography) can aid in the mapping of the coronary anatomy. However, there remain a select few patients with intramyocardial coronaries that provide challenges for surgical dissection during revascularization. Probing the visible portion of the coronary artery, intraoperative cine angiography, thermal angiography, and epicardial Doppler probes have been used to identify the coronary anatomy intraoperatively. Aggressive surgical maneuvers can result in damage and increased time on cardiopulmonary bypass. Previous studies have used epicardial echocardiography on patients undergoing off-pump coronary artery bypass grafting. We report 2 cases in patients undergoing cardiac revascularization on cardiopulmonary bypass where the use of a high-frequency epicardial ultrasound probe facilitated the identification of the embedded coronary arteries. We describe a technique of using antegrade and retrograde cardioplegia administration sequentially to locate the coronary arteries. Easy availability and familiar technology make the epicardial Doppler probe an attractive tool for the identification of embedded coronary arteries.

A case of difficulty predicting neurological deficit during thoracoabdominal aortic surgery

Perioperative spinal cord injury associated with thoracoabdominal aorta (TAAA) surgery is a devastating complication. With variable results, the intraoperative use of neurophysiologic monitoring has been employed for the diagnosis and prevention of spinal cord ischemia. We present a case report of a patient undergoing TAAA surgery with the use of evoked potential monitoring. Intraoperatively, both sensory and motor evoked potentials were utilized and consequently the patient experienced changes in monitoring consistent with a new neurologic deficit. However, postoperatively these changes in evoked potentials never manifested in neurologic injury. We examine the utility of neurophysiologic monitoring as it pertains to TAAA surgery.