Less invasive aortic valve surgery: rationale and technique

The unquestionable aims for a less invasive operations are less morbidity, less discomfort, and a reduced hospital stay through an operation which proves equally durable to the conventional approach. Such an operation must be carried out without further risk to the patient or increased difficulty for the surgeon. Whilst most definitions of less invasive coronary surgery include the phrase without cardiopulmonary bypass, this is clearly not yet possible in valve surgery. In valve surgery, the definition of less invasive relates only to the size of incision and rate of recovery. As a result of the discussions during the Heart Lab International Workshop on video-assisted heart surgery in Zurich, October 22-25, 1998, the following conclusions emerged. The partial upper sternotomy with J- or L- shaped extension to the right is the preferred approach for minimally invasive aortic valve surgery. Other methods which sacrify the internal thoracic arteries, open pleural cavities or predispose to long hernia are less satisfactory. A detailed description of the technique proposed is given and its indications and contraindications are discussed

Simple scoring system to predict in-hospital mortality after surgery for infective endocarditis

BACKGROUND: Aspecific scoring systems are used to predict the risk of death postsurgery in patients with infective endocarditis (IE). The purpose of the present study was both to analyze the risk factors for in-hospital death, which complicates surgery for IE, and to create a mortality risk score based on the results of this analysis. METHODS AND RESULTS: Outcomes of 361 consecutive patients (mean age, 59.1\ub115.4 years) who had undergone surgery for IE in 8 European centers of cardiac surgery were recorded prospectively, and a risk factor analysis (multivariable logistic regression) for in-hospital death was performed. The discriminatory power of a new predictive scoring system was assessed with the receiver operating characteristic curve analysis. Score validation procedures were carried out. Fifty-six (15.5%) patients died postsurgery. BMI >27 kg/m2 (odds ratio [OR], 1.79; P=0.049), estimated glomerular filtration rate 55 mm Hg (OR, 1.78; P=0.032), and critical state (OR, 2.37; P=0.017) were independent predictors of in-hospital death. A scoring system was devised to predict in-hospital death postsurgery for IE (area under the receiver operating characteristic curve, 0.780; 95% CI, 0.734-0.822). The score performed better than 5 of 6 scoring systems for in-hospital death after cardiac surgery that were considered. CONCLUSIONS: A simple scoring system based on risk factors for in-hospital death was specifically created to predict mortality risk postsurgery in patients with IE

L'assistance circulatoire en attente de transplantation. Résultats de la transplantation cardiaque après assistance mécanique de la circulation [Circulatory assistance while waiting for heart transplantation. Outcome of heart transplantation after mechanical circulatory assistance]

In most of the published (uncontrolled) studies, survival after transplantation is similar for patients who required mechanical circulatory assistance and those who did not. Two controlled studies have reported a better survival rate in patients who had preoperative circulatory assistance. Infections are more frequent in transplanted patients who had a period of circulatory assistance preoperatively than in those who were transplanted after medical treatment. The effect of circulatory assistance on heart graft rejection is debated. The same is true for coronary grafts

L'assistance circulatoire en attente de transplantation. Sélection des patients et choix du système d'assistance [Circulatory assistance while waiting for heart transplantation. Patient selection and choice of the assist system]

TWO CLINICAL SITUATIONS: Mechanical circulatory assistance can be indicated in two clinical situations: i) patients on the waiting list for heart transplantation who have chronic heart failure unresponsive to drug therapy and whose clinical status worsens; ii) patients with acute heart failure. The exact indications for mechanical circulatory assistance are difficult to establish. Hemodynamic criteria are no longer sufficient. Circulatory assistance may be proposed for chronic heart failure patients with a high risk of death or in a situation of acute deterioration. Among these patients, several risk factors can be used to establish scores that have a better predictive value than risk factors taken alone. Two predictive models have been recently established. The first one takes into account 7 independent variables: etiology, heart rate at rest, left ventricle ejection fraction, mean blood pressure, intraventricular rhythm disorder, VO2max and serum sodium). In addition to these variables, the second model also includes pulmonary wedge pressure. In selected patients with acute heart failure, circulatory assistance is needed as early as possible to avoid irreversible multiple organ failure. The crucial problem is rapid assessment of the feasibility of heart transplantation. Several variables can be used to predict survival in candidates for mechanical circulatory assistance on the heart transplantation waiting list. They include hemodynamic criteria, renal function, liver function, preoperative infection and the emergency nature of the need for circulatory assistance. The choice depends both on the patient (surface area is important) and the underlying disease

Dynamic Pumping Characteristics of the Hemopump®

While pumping blood with the Hemopump® in sheep, the ability of predicting the instantaneous pump flow from the pressure difference over the pump system and pump parameters was investigated. For rotational speed n between 300 and 475 revolutions per second (rps), maximum pump flow QO(n) at zero pressure difference, internal pump resistance R(n), and inertia parameter Lc were found to be suitable parameters for Hemopump® characterization. The instantaneous pump flow could be estimated with an accuracy of approximately 1.0 [ml/s]. The values of the pump source parameters (± sd) were: (the figures in parentheses represent earlier reported values found while pumping water) Lc was a constant of 21.4 ± 6.4 [Pa·s2/ml] (in water: 10.8). QO(n) is linearly related to rotational speed n according to: QO(n) = Qo(ncen) + CQ(n - ncen), with QO(ncen) = 49.4 ± 4.5 [ml/s] (in water: 60.3), CQ = 142 ± 22.4 [10−3 ml] (in water: 146), and ncen = 387.5 [rps]. R(n) is linearly related to rotational speed n according to: R(n) = R(ncen) + CR(n - ncen), with R(ncen) = 556 ± 124 [Pa·s/ml] (in water: 502) and CR = 1.47 ± 0.83 [Pa·s2/ml] (in water: 1.67)