Q fever endocarditis: over 14 years of surgical experience in a referral center for rickettsioses.

Background And Aim Of The Study: Q fever endocarditis caused by Coxiella burnetii is the most important etiology of negative blood culture endocarditis. Without specific clinical findings, diagnosis is difficult and prevalence of this life-threatening disease is underestimated.

Methods: Q fever endocarditis was assessed in 19 patients (15 men, four women; age range: 36-79 years) by evaluating clinical and echocardiographic criteria and specific serology.

Late results of double-valve replacement with biologic or mechanical prostheses.

Background: We previously showed that the risk of reoperation for structural degeneration of bioprostheses was higher in cases involving patients older than 65 years (p = 0.003) and double-valve replacement (p = 0.02).

Late complications after prosthetic replacement of the ascending aorta: what did we learn from routine magnetic resonance imaging follow-up?

Objective: Advances in surgical technique have improved early survival after surgery of the ascending aorta. However, follow-up data document serious late complications, mainly evolutive peri-prosthetic false aneurysms. Magnetic resonance imaging (MRI) has proved to be highly effective for monitoring these complications.

Clinical evaluation of heparin-coated circuits for routine coronary artery bypass grafting surgery: a prospective randomized study.

The aim of this study was to demonstrate the clinical and biological benefits of heparin-coated circuits in routine coronary artery bypass grafting (CABG). A prospective, randomized study was conducted in 80 patients undergoing routine CABG. Patients were randomized to either noncoated circuits (Group 1) or heparin-coated circuits (Group 2).

Centrifugal pumps and heparin-coated circuits in surgical treatment of giant cerebral aneurysms.

Giant cerebral aneurysms may be untreatable by conventional neurosurgical techniques. Early attempts to use circulatory assistance and deep hypothermia were abandoned due to hemorrhagic complications. More recently, interest in circulatory support for complex neurosurgical procedures has been renewed.

Multiple valve replacement increases the risk of reoperation for structural degeneration of bioprostheses.

Background And Aim Of The Study: The study aim was to analyze the results of reoperations for structural degeneration of bioprostheses, and to define a high-risk population for reoperative procedures.

Methods: A series of 524 consecutive patients who had undergone a first reoperative replacement for a failed bioprosthesis between 1978 and 1998 was reviewed retrospectively. The reoperative procedure comprised 363 single valve replacements, and 161 multiple valve replacements.

Dynamic aortomyoplasty: clinical experience and thoracoscopic surgery feasibility study.

Background: Surgical procedures using the latissimus dorsi (LD) muscle to assist chronic heart failure inflict major trauma on severely sick patients. A less invasive approach may prove beneficial. The aim of this article is to review our clinical and experimental approaches of dynamic aortomyoplasty (AMP) and emphasize the necessity to reorient surgical technique towards new directions and a less invasive thoracoscopic approach.

Study of left ventricular bypass using Wankel type semipulsatile blood pump.

The influence of the Wankel type semipulsatile left ventricular assistance on hemodynamics was investigated with a computer simulation and an animal experiment. A simulation circuit was constructed to express the circulatory system. A current source was added to create a semipulsatile blood pump.

Aortic valve or root replacement with cryopreserved homograft for active infectious endocarditis.

Active aortic endocarditis is a serious condition that carries a high mortality and morbidity. The aim of this study was to analyse results obtained from 24 patients who underwent aortic valve or root replacement with cryopreserved homograft for aortic endocarditis. Eleven patients had native valve endocarditis, and 13 had prosthetic valve endocarditis.

Cora rotary pump for implantable left ventricular assist device: biomaterial aspects.

Our group is developing a left ventricular assist device based on the principle of the Maillard-Wankel rotative compressor: it is a rotary, not centrifugal, pump that produces a pulsatile flow. Stringent requirements have been defined for construction materials. They must be light, yet sufficiently hard and rigid, and able to be machined with high precision.

Physico-chemistry and cytotoxicity of ceramics: part I: characterization of ceramic powders.

The morphology of Al2O3, ZrO2/Y2O3, AIN, B4C, BN, SiC, Si3N4, TiB2, TiC, TiN ceramic, graphite and diamond powders has been studied by scanning electron microscopy (SEM) and the specific area of each powder was determined with the BET method. X-ray diffraction (XRD) investigations have been carried out in order to evaluate the crystallinity and determine the constitutive phases. The chemical composition was assessed by classical chemical analyses and by X-ray microprobe; some powders were studied by the laser micro-Raman technique.

Bone mineral density in patients given oral vitamin K antagonists.

Background: Divergent results have been obtained in studies of bone mineral density in patients under oral vitamin K antagonists.

Objective: To gather prospective data on bone mineral density and bone metabolism in 70 aortic valve replacement patients.

Study Design: 49 patients who had been under oral vitamin K antagonists for at least one year after implantation of a mechanical aortic valve were compared with 21 recipients of a tissue aortic valve that did not require anticoagulant therapy.

Biological evaluation of mechanical circulatory support systems in calves.

Data from animal experiments with mechanical circulatory support systems (MCSS) performed in Groningen and Marseille over the past years were used to obtain normal values of hematological, coagulation, rheological and blood chemistry parameters in calves. These parameters were divided between two groups: a limited number of parameters necessary to assess biocompatibility properties of MCSS quickly and a more extensive number of parameters suitable for more detailed biological evaluation of blood pumps. All applied tests can be examined in calf blood as well as in human blood.

Value of Doppler echocardiography in the detection of low-grade rejections after cardiac transplantation.

Modifications of the diastolic parameters pressure half-time (PHT) and isovolumic relaxation time (IVRT), recorded using cardiac Doppler echocardiography (CDE), were studied in 23 heart transplant recipients and compared to the results of 345 endomyocardial biopsies (EMB) performed on the same day. Two different protocols, analyzing respectively (1) a decrease of 20% or more in IVRT and/or PHT with respect to the mean and (2) a decrease of 20% or more in IVRT and/ or PHT with respect to its preceding value, were used to evaluate the efficiency of CDE in diagnosing mild and moderate rejections. When a mild rejection was detected by EMB, a statistically significant decrease was found in the average CDE parameter values of the patient population.

Cora valveless pulsatile rotary pump: new design and control.

For decades, research for developing a totally implantable artificial ventricle has been carried on. For 4 to 5 years, two devices have been investigated clinically. For many years, we have studied a rotary (but not centrifugal) pump that furnishes pulsatile flow without a valve and does not need external venting or a compliance chamber.

Circulatory assist techniques after cardiomyoplasty. Determinants for clinical outcome and later consequences.

Cardiomyoplasty, in spite of recent improvements, remains a high risk operation. The early postoperative period is sometimes very critical, even for patients selected from preoperative New York Heart Association functional class IV. During the surgical period, poor hemodynamics may be responsible for early death, as well as influence latissimus dorsi muscle long-term viability.

Clinical situations and results of cardiopulmonary support by peripheral access for resuscitation and recovery.

Use of cardiopulmonary support (CPS) by peripheral access with a membrane oxygenator has made considerable progress as a result of the development of centrifugal pumps, percutaneous cannulation, and preheparinized circuits. We have used CPS for resuscitation in 3 cases, for recovery after cardiotomy in 6 cases (myocardial insufficiency, 4; pulmonary arterial hypertension, 1; respiratory insufficiency, 1), and after heart transplantation in 1 case. Of these 10 patients, 3 died during CPS, 5 were successfully weaned, and 2 underwent heart transplantation.