As greater numbers of heart failure patients are given the option of mechanical circulatory support (MCS) as bridge-to-transplant therapy as well as destination therapy, physicians and practitioners across specialties will need to have working access to cursory knowledge of the physiology and anatomic placement of these cardiac devices. As this unique patient population experiences both enhanced length and quality of life, the incidence of patients on MCS who develop both acute and more slowly developing general surgical problems that require intervention will continue to rise. It is expected that over time this emphasis will shift from acute general surgical problems related to initial device placement to a greater proportion of outpatient and more traditional general surgical problems as both mechanical circulatory devices and care methods advance.

Thus it becomes necessary to establish protocols and models for inter-professional and inter-specialty communication and care systems to best and most comprehensively meet the needs of these patients. The general surgeon must possess a cursory knowledge of the pathophysiology, surgical placement of mechanical devices, and their unique operative challenges in order to adapt and formulate a therapeutic plan that addresses the need for innovation both to address intraoperative challenges and successfully accomplish the general surgical goals and minimize the instances of complications. The anesthesiologist must understand the cardiopulmonary pathophysiology and principles underlying the function of these devices in order to best develop an anesthetic care plan and prepare for effects of surgical manipulation and positioning and anticipate the unique needs of this patient population.

It is our hope that this chapter will serve as a guide to the unique general surgical issues faced by patients on mechanical circulatory support, strategies for patient management in the perioperative period, unique challenges posed by the patient on mechanical circulatory support, and the potential complications, outcomes, and effects of general surgical intervention in this growing patient population.

The anesthesiologist, cardiac, or otherwise managing the patient on mechanical circulatory has a wide variety of monitoring options and techniques at their disposal that he or she must tailor to the individual needs of the patient and the specific nature of each noncardiac case.

The choice of vital monitoring formats has varied across the literature with physician preference, patient condition, and working experience with the LVAD patient population. In self-reported data, the routine use of invasive monitoring for noncardiac cases in LVAD patients was inversely associated with institutional volume and was reportedly used in up to 83% of the time for minor noncardiac surgical procedures in low-volume institutions (65% for high volume) and 50% reporting use of arterial catheters for blood pressure monitoring during endoscopic procedures [6]. However, since the VAD apparatus can provide data on cardiac output, it is possible to forgo invasive monitoring when appropriate for the individual. Ahmed et al. (2012) have shown in their series that it is possible to manage patients safely without routine central lines, Swan-Ganz catheters, and transesophageal echocardiography [7]. In a majority of cases, invasive arterial lines can be avoided for pressure monitoring provided pulsatility is preserved and external monitoring can be carried out [8]. This same principle applies to the use of pulse oximeter, which is sufficient for monitoring of oxygenation, though serial arterial blood gases can be used if there are concerns for its accuracy [1]. It is likely that in the absence of extensive comorbidities, the use of invasive monitoring is more closely associated with physician and staff familiarity with operatively managing patients on mechanical circulatory support and that incidence of its uses may decline as more widespread experiences with this patient population increase.

When initiating general anesthesia in this patient population, it is particularly important to take measures to ensure the peripheral effects of vasodilatory drugs, and mechanical ventilation does not interfere with proper VAD function. It is essential to maintain preload and support right ventricular function in the LVAD patient. Negative inotropic drugs should be used with caution, and the use of positive inotropes or selective pulmonary vasodilators may be employed if right ventricular dysfunction, signified by increasing central venous pressure in tandem with low cardiac output, is encountered [9, 10]. Routine use of prophylactic infusion of milrinone may be implemented to prevent dysfunction and guard against increases in the pulmonary vascular resistance according to physician preference [11]. Though conventional techniques are generally well tolerated and fluid requirements are not necessarily vastly different than the non-VAD patient in elective procedures, induction must proceed in a manner that supports the contractility of the right ventricle in the LVAD patient in order to maintain left-sided pump filling [10, 12, 13]. The possibility of preload reduction secondary to vasodilation combined with the negative effects of positive-pressure ventilation on venous return renders the need for adequate pre-procedural fluid optimization and appropriate tidal volume and PEEP settings essential to maintaining pump function as well as preserving pulsatility for external blood pressure monitoring [12–14]. In a similar manner, in axial-flow pump support reduction of increases in systemic vascular resistance and hypertension is advisable to guard against pump failure and poor perfusion [15]. These techniques can be used in combination or separately according to each patient’s clinical scenario in order to best optimize intraoperative care and ensure the best possible patient outcome.

Depending on the patient’s particular surgical problem, type of device, and surgeon familiarity with conducting surgery in this unique patient population, the presence of mechanical circulatory support may or may not alter the surgical plan in regard to choosing the surgical approach, positioning, and other operative factors.

Secondary to the hemodynamics of LVAD devices, patient positioning can affect the filling pressures. The surgical and anesthesia teams should be well aware of the possibility for the development of position-dependent hypotension. Goldstein et al. (1995) note this complication with patients positioned in left lateral decubitus and remark that dobutamine therapy in an attempt to increase cardiac preload is counterproductive and worsened the development of hypotension; when fluid resuscitation was provided prior to induction, hemodynamic stability was achieved throughout the operative period in the subsequent cases eliminating the need for vasopressors or transfusion. As such, the patient’s position and preoperative fluid balance must be taken into account in order to avoid intervention that can strain the heart and risk destabilizing pump mechanics.

Interestingly, despite the challenges that VADs pose for patient positioning, reported cases have shown that it is possible to safely conduct surgical procedures in the prone position. In one case, positioning was directed by the surgeon and perfusionist in order to avoid traction or excessive force on the driveline and other components and surgery proceeded uneventfully with the use of radial arterial line for pressure monitoring without the patient experiencing any hemodynamic instability [16]. Other cases, however, describe VAD patients experiencing decreases in right ventricular cardiac output due to the effects of positioning and low fluid status. It is thought that the compression of the RVOT by the outflow cannula led to the obstruction of flow in the first case, and both cases were remedied by patient response to fluid bolus [17]. Cases such as these demonstrate that with proper attention to detail and responsiveness to hemodynamic changes, VAD patients are able to tolerate a variety of positioning challenges.

When undertaking a laparoscopic approach, both the positioning of port sites in relation to the device and driveline and the potential consequences of pressurizing the abdomen must be taken into consideration. Insufflation may have significant effects on hemodynamic parameters such as cardiac preload. Second-generation LVADs are significantly dependent on preload, a cardiac parameter which may decrease with abdominal insufflation [14]. Insufflation should occur slowly with careful monitoring of the arterial blood pressure. Morgan et al. (2012) note that the typical positioning for laparoscopic procedures has the potential to exacerbate this aspect of pathophysiology by increasing upward pressure on the diaphragm and thereby decreasing venous return. In the series by Ahmed et al. (2012), patients undergoing laparoscopic procedures were insufflated to 10 mmHg and only increased to 12 mmHg in the event that better visualization was needed, no complications or adverse effects on cardiac function parameters at these pressures. Insufflation should commence slowly with caution and used in a manner that balances the optimization of surgical field of vision without destabilizing the patient’s hemodynamic function.