Establishing an association between a peri-operative perfusion score system (PerfSCORE) and post-operative patient morbidity/mortality during CPB cardiac surgery.

Background: To date, there is no quality assurance program that correlates patient outcome to perfusion service provided during cardiopulmonary bypass (CPB). A score was devised, incorporating objective parameters that would reflect the likelihood to influence patient outcome. The purpose was to create a new method for evaluating the quality of care the perfusionist provides during CPB procedures and to deduce whether it predicts patient morbidity and mortality.

Small access (30F) clinical central venous smart cannulation: is it adequate?

Objectives: To assess the performance of 45F vs. 36F smartcanula in CPB with gravity drainage alone.

Methods: Twenty patients were randomly assigned to two groups receiving for venous drainage a smartcanula which is collapsed over a mandrel for trans-atrial insertion into the inferior vena cava and expanded in situ to either 45F or 36F.

Effects of an aging vascular model on healthy and diseased hearts.

The vitamin D(3) and nicotine (VDN) model is a model of isolated systolic hypertension (ISH) due to arterial calcification raising arterial stiffness and vascular impedance similar to an aged and stiffened arterial tree. We therefore analyzed the impact of this aging model on normal and diseased hearts with myocardial infarction (MI). Wistar rats were treated with VDN (n = 9), subjected to MI by coronary ligation (n = 10), or subjected to a combination of both MI and VDN treatment (VDN/MI, n = 14).

Comparing oxygen transfer performance between three membrane oxygenators: effect of temperature changes during cardiopulmonary bypass.

Recently, a new oxygenator (Dideco 903 [D903], Dideco, Mirandola, Italy) has been introduced to the perfusion community, and we set about testing its oxygen transfer performance and then comparing it to two other models. This evaluation was based on the comparison between oxygen transfer slope, gas phase arterial oxygen gradients, degree of blood shunting, maximum oxygen transfer, and diffusing capacity calculated for each membrane. Sixty patients were randomized into three groups of oxygenators (Dideco 703 [D703], Dideco; D903; and Quadrox, Jostra Medizintechnik AG, Hirrlingen, Germany) including 40/20 M/F of 68.

A novel device for reducing hemolysis provoked by cardiotomy suction during open heart cardiopulmonary bypass surgery: a randomized prospective study.

Since the inception of cardiopulmonary bypass (CPB), little progress has been made concerning the design of cardiotomy suction (CS). Because this is a major source of hemolysis, we decided to test a novel device (Smartsuction [SS]) specifically aimed at minimizing hemolysis during CPB in a clinical setting. Block randomization was carried out on a treated group (SS, n=28) and a control group (CTRL, n=26).

The effect of a myocardial infarction on the normalized time-varying elastance curve.

It has been suggested that the shape of the normalized time-varying elastance curve [E(n)(t(n))] is conserved in different cardiac pathologies. We hypothesize, however, that the E(n)(t(n)) differs quantitatively after myocardial infarction (MI). Sprague-Dawley rats (n = 9) were anesthetized, and the left anterior descending coronary artery was ligated to provoke the MI.

Ventricular-arterial coupling in a rat model of reduced arterial compliance provoked by hypervitaminosis D and nicotine.

The vitamin D(3) and nicotine (VDN) model is one of isolated systolic hypertension (ISH) in which arterial calcification raises arterial stiffness and vascular impedance. The effects of VDN treatment on arterial and cardiac hemodynamics have been investigated; however, a complete analysis of ventricular-arterial interaction is lacking. Wistar rats were treated with VDN (VDN group, n = 9), and a control group (n = 10) was included without the VDN.

Infarct-remodeled myocardium is receptive to protection by isoflurane postconditioning: role of protein kinase B/Akt signaling.

Background: Postinfarct remodeled myocardium exhibits numerous structural and biochemical alterations. So far, it is unknown whether postconditioning elicited by volatile anesthetics can also provide protection in the remodeled myocardium.

Methods: Myocardial infarct was induced in male Wistar rats by ligation of the left anterior descending coronary artery.

A novel technique using echocardiography to evaluate venous cannula performance perioperatively in CPB cardiac surgery.

Objective: Transthoracic echocardiography (TTE) has been used clinically to disobstruct venous drainage cannula and to optimise placement of venous cannulae in the vena cava but it has never been used to evaluate performance capabilities. Also, little progress has been made in venous cannula design in order to optimise venous return to the heart lung machine. We designed a self-expandable Smartcanula (SC) and analysed its performance capability using echocardiography.

Noninvasive Doppler-derived myocardial performance index in rats with myocardial infarction: validation and correlation by conductance catheter.

The rodent model of myocardial infarction (MI) is extensively used in heart failure studies. However, long-term follow-up of echocardiographic left ventricular (LV) function parameters such as the myocardial performance index (MPI) and its ratio with the fractional shortening (LVFS/MPI) has not been validated in conjunction with invasive indexes, such as those derived from the conductance catheter (CC). Sprague-Dawley rats with left anterior descending coronary artery ligation (MI group, n = 9) were compared with a sham-operated control group (n = 10) without MI.

The Smartcanula: a new tool for remote access perfusion in limited access cardiac surgery.

Devices for venous cannulation have seen significant progress over time: the original, rigid steel cannulas have evolved toward flexible plastic cannulas with wire support that prevents kinking, very thin walled wire wound cannulas allowing for percutaneous application, and all sorts of combinations. In contrast to all these rectilinear venous cannula designs, which present the same cross-sectional area over their entire intravascular path, the smartcanula concept of "collapsed insertion and expansion in situ" is the logical next step for venous access. Automatically adjusting cross-sectional area up to a pre-determined diameter or the vessel lumen provides optimal flow and ease of use for both, insertion and removal.

Vascular access for cardiopulmonary bypass procedures.

Since the initiation of cardiac surgery using cardiopulmonary bypass, little progress has been made concerning the design of catheters for vascular access. However, in the last few years, research in this specialized field has established that catheter performance not only depends on size but also on the catheter's design. The catheter's drainage hole surface area correlates with its performance, i.

Right atrial surgery with unsnared inferior vena cava.

Right atrial procedures require snaring the venous cannulas to prevent air entrapment in the venous line. In particular situations with complex congenital morphology and/or presence of severe pericardial adhesions the right atrial opening without the inferior vena cava cannula in the surgical field and without dissecting and snaring the inferior vena cava itself, might substantially facilitate the surgical technique, provided an adequate venous drainage is assured to avoid flow reduction or circulatory arrest. In several patients with congenital or acquired heart disease with potentially complicated venous drainage, like extracardiac Fontan procedure and tricuspid valve replacement, cardiopulmonary bypass was conducted either on normothermia (congenital lesions) or with mild hypothermia (acquired disease), with 3 l/min per m(2) flow index and venous drainage through femoral vein cannulation.

Limitations using the vacuum-assist venous drainage technique during cardiopulmonary bypass procedures.

Vacuum-assist venous drainage (VAVD) can increase venous blood return during cardiopulmonary bypass (CPB) procedures. However, the negative pressure created in the closed cardiotomy reservoir can be transmitted to the oxygenator if a nonocclusive or centrifugal arterial pump is used, resulting in bubble transgression (BT) from the gas to blood compartment of the oxygenator. We analyzed the vacuum pressure required to produce BT using an in vitro circuit including successively a closed reservoir, a pump (centrifugal or roller), and an oxygenator.

Miniaturization in cardiopulmonary bypass.

Cardiopulmonary bypass (CPB) remains the key technology for more complex cardiac operations. The perfusion equipment used nowadays has seen tremendous progress since its introduction into clinical practice 50 years ago. However, overall, CPB is still far from perfect.

Air filtering capacity of an integrated cardiopulmonary bypass unit.

To limit the morbidity of cardiopulmonary bypass (CPB), a new concept of integrating pumping, oxygenation, and air removal into a single unit has been developed (CardioVention Inc., Santa Clara, CA). The air filtration capacity of this system was tested.

A prototype paediatric venous cannula with shape change in situ.

During cardiopulmonary bypass (CPB), venous drainage may be impeded due to small vessel and cannula size or chattering, thus, blood return to the heart-lung machine is reduced. We designed a self-expandable prototype cannula, which is able to maintain the vein open and overcome this problem and analysed its performance capability. This prototype and several other cannulae were tested using an access vessel diameter of 7 mm.

A new expandable venous cannula for minimal access heart surgery.

Background: During percutaneous cannulation, the diameter of the venous cannula is determined by the size of the access site. To limit this restriction, the Smart cannula (Cardiosmart Ltd., Fribourg, Switzerland) has been developed.

Antithrombotic properties of trillium coated connectors.

Trillium coating (Medtronic Inc., Minneapolis, MN) offers, in addition to the presence of heparin, endothelium-like properties of its negatively charged surface. Its thromboresistant properties on coated connectors are tested here and compared with uncoated standard connectors, as well as with the Carmeda BioActive surface (CBAS) heparin surface coating.

A new concept of integrated cardiopulmonary bypass circuit.

Objective: Standard cardiopulmonary bypass (CPB) circuits with their large surface area and volume contribute to postoperative systemic inflammatory reaction and hemodilution. In order to minimize these problems a new approach has been developed resulting in a single disposable, compact arterio-venous loop, which has integral kinetic-assist pumping, oxygenating, air removal, and gross filtration capabilities (CardioVention Inc., Santa Clara, CA, USA).

[Paediatric mechanical cardiac assistance].

The mechanical cardiac assistance, once limited only to the adult patients, is now progressively extended to the paediatric population, including neonates. Currently for children with cardiorespiratory insufficiency requiring for a mechanical assistance there are available several options: Intra-Aortic Balloon Pump, Extra-Corporeal Membrane Oxygenation (ECMO) et le Ventricular Assist Device. From April 1999 in our Department of Cardiovascular Surgery at CHUV 8 children, including 4 neonates, have been treated with ECMO.

Flow dynamic comparison of peripheral venous cannulas used with centrifugal pump assistance in vitro.

Because of the risk of vein collapse, the benefits of using a centrifugal pump to assist venous drainage for cardiopulmonary bypass are limited when the tips of peripheral cannulas are maintained within the vena cava. Using a mock circuit including 20 mm diameter latex tubing to mimic a vena cava, we compared the performance of 6 commercially available peripheral venous cannulas and attempted to determine potential factors influencing maximal flow drainage before vein collapse. A close correlation was observed with the total hole area of the cannula.