Objective The aim of this study was to compare the early systemic inflammatory response of the Resting Heart System (RHS; Medtronic, Minneapolis, MN USA), a miniaturized cardiopulmonary bypass (CPB) system, with two groups using a standard extracorporeal circulation system during on-pump coronary artery bypass grafting (CABG) surgery. Methods A total of 60 consecutive patients requiring CABG were prospectively randomized to undergo on-pump CABG using conventional CPB without cardiotomy suction (group A), conventional CPB with cardiotomy suction (group B), or the RHS (group C). Blood samples were collected at five time points: immediately before CPB, 30 minutes into CPB, immediately at the end of CPB, 30 minutes post-CPB, and 1 hour post-CPB. Inflammation was analyzed by changes in (a) levels of plasma proteins, including inflammatory cytokines (interleukin-6 [IL-6], IL-10, and tumor necrosis factor-α), chemokines (IL-8, monokine induced by interferon-γ, monocyte chemotactic protein-1, regulated on activation normal T cell expressed and secreted, and interferon-inducible protein-10), and acute phase proteins (C-reactive protein and complement protein 3); (b) biochemical variables (cardiac troponin I, hematocrit, and immunoglobulin G); and (c) cell numbers (leukocytes, neutrophils, and thrombocytes). Results The RHS showed more delayed secretion of the cytokines tumor necrosis factor-α and IL-10, chemokines monokine induced by interferon-γ (P < 0.001); IL-8, and interferon-inducible protein-10; and complement protein 3 than conventional CPB systems did. Median thrombocyte numbers were higher in the RHS group. Levels of cardiac troponin I, monocyte chemotactic protein-1, and IL-6 were lower in both the RHS and conventional CPB without suction than with suction. Levels of C-reactive protein and regulated on activation normal T cell expressed and secreted, plus leukocyte and neutrophil numbers, were similar in all groups. Conclusions The Medtronic RHS may induce less systemic inflammation than conventional CPB systems, particularly when cardiotomy suction was used, but it did not result in improved clinical benefit.

Giant partially thrombosed intracranial aneurysms are a challenge to treat surgically, and they are also unsuitable for coil embolization. The current options for treatment include extracranial-intracranial bypass followed by parent artery occlusion or direct surgical occlusion in which deep hypothermic circulatory arrest is used. The authors report the use of another approach in the treatment of a giant anterior circulation aneurysm: selective brain cooling accomplished by extracorporeal perfusion. This facilitated direct surgery on a 4.2-cm, partially thrombosed aneurysm of the middle cerebral artery (MCA). A brain temperature of 22 degrees C was achieved after 20 minutes of perfusion with blood cooled using an extracorporeal technique of femoral-common carotid artery perfusion. This was followed by a 20-minute period of surgical trapping of the MCA, then evacuation and clip occlusion of the aneurysm. During the period of selective brain cooling the patient's core body temperature was maintained above 35 degrees C. This technique of selective brain cooling may be a useful alternative to currently available surgical and endovascular methods of treatment for giant aneurysms.

The purpose of this study is to determine the appropriate arterial pump flow /cardiac index (CI) utilizing a mini-bypass system. The unique feature of most mini-bypass systems is that the centrifugal pump combines the function of kinetic venous drainage with arterial pump flow. Therefore, if drainage is reduced, arterial pump flow is also reduced. Managing this system can present challenges to the clinical perfusionist. We reviewed fifteen cases, using the Medtronic Resting Heart System (RHS). This retrospective study examined the arterial pump flow, measured as cardiac index (CI), mean arterial pressure, inlet venous saturation, urine output, vasopressor use, and lactate production during routine cardiac surgery. The mean cardiac index for all patients was 1.90 +/- 0.14, range 1.63-2.08 L/min/m(2). The mean hemoglobin on cardiopulmonary bypass (CPB) was 10.6 +/- 1.2, with a range of 9.2-13.3 g/dL. The lactate produced on CPB was 2.03 +/-0.67 with a range of 1.5-3.5 mmol/L. The mean change in lactate measured from pre CPB to post CPB was 0.85 +/- 0.71 with a median lactate of 0.6 mmol/L. The venous saturation was 65.53 +/- 6.03% with a median of 65% and a range of 57-82%. The mean arterial pressure was 67.04 +/- 10.45 mmHg with a median of 62.5 mmHg. The median urine output was 125 mls. The vasopressor median was 2200 microg. All patients were maintained on CPB with a mean nasopharyngeal temperature of 35.43 degrees Celsius. Despite using lower than predicted flows, it would appear that adequate perfusion is provided. The higher hemoglobin content achieved through reduced hemodilution and reduced inflammation appears to enable this system to deliver adequate flow and perfusion at reduced cardiac indices. This research provides evidence which challenges longstanding beliefs that a cardiac index of 2.4 L/min/m(2) is required for all cases.

The Medtronic Resting Heart System alleviates many factors, such as high shear stress, turbulence, air to blood interface and decreased oncotic pressure caused by hemodilution, providing more efficient perfusion to our MIMVS patients. We demonstrate, with minor circuit modifications and attention to venous air issues, that this mini-circuit can be used safely and effectively, while being associated with improvements in patient outcomes.