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Biomedical subjects

J Szefner

Publications and source records attributed to J Szefner.

At least 19 recordsLinked to original sources

Preventing, minimizing, and managing postoperative bleeding.

BACKGROUND: Most bleeding in cardiovascular surgery is biological, not surgical, the result of disseminated intravascular coagulation in its latter phases. Disseminated intravascular coagulation bleeding affects all levels of the coagulation systems, requiring stabilization of the platelet system, balancing the procoagulant system and its regulation, and stopping the fibrinolytic system's activation. METHODS: The article discusses the multisystem protocol put into place at the Cardiovascular Surgery Department of La Pitié Hospital in Paris to diagnose and treat DIC bleeding so as to slow down causes of its occurrence and prevent further deterioration of the hemostatic systems. RESULTS: All biological bleeding was controlled, permitting detection of other causes of bleeding and allowing rational use of blood products. No thromboembolic accident occurred. There was an absence of iatrogenic bleeding. The protocol also detects disseminated intravascular coagulation in patients who did not bleed to take early and frequently lifesaving measures. CONCLUSIONS: This demonstrates the need to treat bleeding through a multisystem approach, monitoring its evolution by means of biological tests to be able to provide appropriate treatment.

Blood Coagulation Tests↗

Left centrifugal pump cardiac assist with transseptal percutaneous left atrial cannula.

Left cardiac support postcardiotomy requires a second operation for removal of the atrial cannula following weaning from assistance. To avoid the risk of this procedure, we used a transseptal cannula prototype. The cannula was introduced percutaneously through the femoral vein and advanced into the left atrium guided by the finger of the surgeon. Optimal positioning of the tip of the cannula was verified by perioperative transesophageal echocardiography. A long arterial cannula was positioned in the descending aorta via the femoral artery and a Carmeda circuit with a centrifugal pump was connected to both cannulas. This procedure was used in 3 patients with low cardiac output who underwent emergency surgery, a 63-year-old patient referred for aortic and mitral valve replacement, a 54-year-old man for aortic valve replacement, and a 64-year-old patient in the acute phase of myocardial infarction after myocardial revascularization. The assistance was used systematically at the end of the operation. The assist flow was 1.2-2.6 L/min. The patients were all weaned from support between 18 h and 8 days later. No complications related to the device occurred. Both cannulas were removed surgically from the femoral vessels without reopening the chest. This new procedure is of interest for 2 reasons: the systematic implantation allows for early assistance, and the use of a percutaneous approach avoids the risk of reopening the chest. More cases are needed to confirm this initial good impression.

Aortic Valve Insufficiency↗

[The cardiowest total artificial heart: experience of 29 cases].

The authors studied the outcome of multi-organ failure in 29 patients with terminal cardiac failure and maintained with a Cardiotest total artificial heart whilst waiting for cardiac transplantation. Pre-implantation organ dysfunction was defined by the following criteria; assisted respiration of over 3 days, total billirubin and creatinine levels of over 2 mg/dL, a platelet count of less than 80,000/mL or a prothrombin ratio of less than 50% and central nervous system disturbances. Fourteen patients died during the period of circulatory assistance and 71% of deaths were due to multi-organ failure. Pre-implantation plasma total bilirubin levels were significantly higher in patients who died of multi-organ failure (p = 0.04). Eighty per cent of patients who died of multi-organ failure had at least 3 criteria of organ dysfunction before implantation of the artificial heart compared with only 37% in the other patients (p = 0.04). Finally, systemic vascular resistances before implantation were significantly lower in patients who died of multi-organ failure. The results of this study suggest that multi-organ failures does not develop during the period of circulatory assistance but represents an aggravation of a preexisting morbid condition. This observation should lead to a limitation of the indications of total circulatory assistance in some cases and, above all, to earlier intervention before multi-organ failure becomes irreversible.

Adult↗

[CardioWest, a complete artificial heart, the French experience].

The development of implantable electric assist systems for the left ventricle cannot be used in all patients. Approximately one-third of them who could benefit from circulatory support while waiting for transplantation also require a supporting system for the right ventricle. In addition, the small number of available donor organs means that only those patients with the best prognosis can be transplanted. From January 1993 to December 1995, 36 patients (33 men, 3 women) mean age 41 years (range 19-60) were treated with a total artificial heart system, CardioWest at the La Pitié Hospital in Paris and at the Laennec Hospital in Nantes, France. Heart assist lasted 1 to 138 days (mean 31 days). Indications were terminal heart failure due to dilated (n = 21) or ischemic (n = 11) cardiomyopathy and 4 high-risk indications (chronic rejection, primary failure, hereditary heart disease, polyvalve disease). Twenty-two of these patients (61.1%) were transplanted. By using strict selection criteria, the total artificial heart CardioWest was able to maintain satisfactory hemodynamic conditions until transplantation without compromising the small number of donor organs available. The total artificial heart is the best system available for total circulatory support in case of dual ventricular failure. The risk of infection is low and the rate of thrombo-embolic events is reduced when care is taken in controlling coagulation, allowing long-term support. Independently of the experience of the different teams, CardioWest is the only device currently available allowing total heart support; its use is justified in particular when other assist devices are unsuccessful.

Adult↗

Clinical experience with a total artificial heart as a bridge for transplantation: the pitie experience.

Since April 1986, 82 patients have received a pneumatic total artificial heart, 62 a JARVIK-7, and 20 a Cardiowest. The duration of support ranged from less than 1 day to 603 days (mean duration: 27 +/- 82). The indications were for acute shock (38 cases) or for chronic deterioration on the transplant waiting list (44 cases). The etiology was mainly due to idiopathic and ischemic cardiomyopathy. With the help of our scoring system, we divided our patients in three groups: Chronic Implantation, represented by two females staying on device for 6 and 19 months, respectively; a High-Risk group of 29 patients characterized by high-risk indications; graft failure, rejection, postcardiotomy patient, postpartum cardiomyopathy, and valvular and congenital reoperation. In addition, the dilated and ischemic cardiomyopathy patients with a score over 6 were included in this group; and an Elective Indication group (51 patients) represented all of the dilated and ischemic cardiomyopathy patients with a score under 6. Due to the shortage of donors, our criteria for transplantation are very strict. Transplants should be made only in cases of hemodynamic stability, on an extubated patient with normal renal and liver functions, without coagulation problems or infection. With such criteria, in the high-risk group, only four patients could be transplanted and of these two are still alive. In contrast, in the elective group, 31 were transplanted (61%), and 71% of these patients were discharged. The rate is improved in the most recent cases, with 90% of the Cardiowest patients being survivors.

Acute Disease↗

Control and treatment of hemostasis in cardiovascular surgery. The experience of La Pitié Hospital with patients on total artificial heart.

The hemostasis protocol applied at the Cardiovascular Surgery Dept. of La Pitié Hospital has greatly reduced thromboembolic accidents and excessive bleeding, with consequent benefits for patients as well as cost reduction. Protocol also has been adopted for patients implanted with a circulatory assist device or a TAH. This paper presents our criteria on supervision and treatment of coagulation with such patients, who reflect all the acquired pathology in clinical hemostasis. From 04/86 to 07/94, 82 patients underwent TAH as a bridge to transplantation. Mean age: 38. Overall duration of mechanical support: 1930 days (mean: 23), of which 137 and 603 for 2 patients. Average duration of CPB: 150 min. Systematic approach to complex TAH-blood interaction and pre-operative multiple organ dysfunction used to control bleeding and/or thromboembolism after CPB. In addition to routine tests, specific regular testing was carried out at least once a day for platelet functions, for thrombin formation and its regulatory pathways, and for the fibrinolytic system. Patients were treated with small doses of Heparin, large doses of Dypyridamole, small doses of Aspirin, modulated doses of Aprotinin, Ticlopidine, Pentoxifylline, FFP, as well as Fibrinogen and AT III concentrates. Dosage was adapted to patient's clinical profile as well as to test interpretation criteria to provide personalized treatment. DIC, widely present in its different phases, was thus diagnosed and treated. All DIC bleeding was controlled, making it possible to detect other causes of post-operatory bleeding and use blood derivates rationally. There were no thromboembolic complications and no iatrogenic bleeding. TAH explanation shows no evidence of macroscopic clots in high risk sites, confirmed by microscopic analysis.

Adolescent↗

Reduction of haemorrhagic complications during mechanically assisted circulation with the use of a multi-system anticoagulation protocol.

Two different anticoagulation protocols were used in 49 consecutive patients mechanically supported either for bridge to transplantation (11) or for recovery of myocardial function after cardiac surgery (35). In 46 patients a Biomedicus centrifugal pump was used and in 3 patients a Pierce-Donachy ventricles. Mechanical support was provided to the left ventricle in 14 patients, to the right ventricle in 6 and to both ventricles in 12 patients; an extra-corporeal membrane oxygenator (ECMO) support was used in 17 patients. Thirty-seven males and 12 females, aged 0.2 to 58 years, were supported for an average time of 6.3 days (range 1-43). Anticoagulation was either based on a continuous infusion of heparin in the first 27 patients (group A) or on a multi-system therapy ("La Pitié" protocol) in the other 22 patients (group B). Overall survival rate was 47%. Patients in group A had a 30% (8/27) survival rate, whereas in group B a 68% (15/22) survival rate was observed (p = 0.006). Transplantation and ventricular assist device (VAD) removal was successfully obtained in 59% (16/27) and 91% (20/22) of patients in group A and group B respectively (p = 0.05). Significant bleeding occurred in 21 patients (81%) in group A and in 2 (9%) of group B (p = 0.001). In these patients bleeding averaged 230 +/- 231 ml/kg in group A versus 55 +/- 18 ml/kg in group B (p = 0.001). Surgical revision was necessary for cardiac tamponade or persistent bleeding in 12 patients of group A (25 procedures: mean 0.9/patient) and in 3 patients of group B (one each patient: mean 0.1/patient) (p = 0.01). Infection, thrombo-embolism and brain hemorrhage were also less frequent in group A than in group B. Our data suggest that the "La Pitié" protocol provides a better control of bleeding than the conventional heparin infusion in patients receiving assist device. this reduction in thrombo-hemorrhagic complications might improve the results of mechanical circulatory support.

Adolescent↗

Heart and heart-lung transplantation in the 1990s.

After 22 years of clinical application in our unit, heart transplantation is now an accepted therapeutic method. Its indications are well established, its surgical technique and post-operative control and treatment well defined, mostly due to better diagnosis of the rejection episodes with the aid of echocardiography and endomyocardial biopsy and the use of cyclosporin. The results are remarkable with a survival rate of 70% at 5 years, and a full rehabilitation into family, social and often professional life for almost all the survivors. Its use has dramatically changed the prognosis of patients with irreversible cardiac failure but underlines the lack of a sufficient number of donors' hearts. The heart-lung transplantation, making use of the progress of heart transplantation, has been used successfully since 1982 and for the first time in Europe by our group. Improvement in the selection of recipients, lung preservation, surgical technique and post-operative management have brought a new and real hope to patients not only irreversible cardiopulmonary lesions but also terminal pulmonary disease.

Heart Transplantation↗

Factors affecting survival in total artificial heart recipients before transplantation.

To identify factors affecting the successful bridge to transplantation, experience with 32 recipients of the Jarvik-7 artificial heart was reviewed. Between patients with and without a successful bridge, there were no significant differences in preoperative hepatorenal function or postoperative hemodynamics, but there were significant differences in body size. When recipients were divided according to body surface areas of less than or greater than 1.8 m2, the smaller patients more frequently developed respirator dependence (73% vs. 18%, p less than 0.01), renal failure (53% vs. 18%, p less than 0.05), and hepatic failure and sepsis, resulting in less frequent qualification for transplantation (20% vs. 65%, p less than 0.05). There were no successful bridge operations in seven patients with body surface areas of less than 1.7 m2, and only one success in nine patients who were less than 170 cm in height, despite use of a smaller stroke volume model. The smaller patients had poorer ventricular filling, which was largely compensated for by the drive controls set for significantly longer diastole and higher vacuum, resulting in similar hemodynamics between the groups. The results suggest that device fitting as manifested by body size is an important factor affecting major organ recovery and subsequent transplantation in recipients of the Jarvik-7 artificial heart. A paracorporeal device may be advisable for patients with body surface areas of less than 1.8 m2 or who were less than 175 cm in height until an even smaller model with a better fit in the thorax becomes available.

Adult↗

Heart transplantation: La Pitié experience, 1968-1989.

Heart transplantation is now an accepted therapeutic modality for end-stage heart disease. However, better immunosuppressive treatments and new methods to monitor rejection or detect early atherosclerosis must be developed to improve the long-term results after heart transplantation.

Cardiomyopathies↗

Total artificial heart: survival and complications.

A total artificial heart was implanted in 28 patients as a bridge to transplantation. Mean time of mechanical support was 14.8 +/- 10 days. The 70-mL Jarvik-7 was used in 12 patients and the 100-mL Jarvik-7 in the remaining 16. No clinical thromboembolic complications occurred during implantation. There was no postoperative bleeding requiring operation. Both survival and the rate of complications were similar in the two Jarvik-7 groups. Eleven patients underwent successful transplantation, and 1 patient is still on mechanical support. Sepsis and multiple-organ failure were the most important causes of death. All patients receiving the total artificial heart for severe acute rejection after transplantation died of infection. Early implantation of the total artificial heart is advised in younger patients and in older patients with acute cardiac failure. The use of this device should be contraindicated in immunosuppressed patients because of the high risk of infection.

Adult↗

Orthotopic transplantation after implantation of a Jarvik 7 total artificial heart.

A total artificial heart was used to support the circulation in 33 heart transplantation candidates who were expected to die before procurement of a donor heart. Twelve of these patients (mean age 35 +/- 10 years) underwent cardiac transplantation. Another patient is still being supported with the total artificial heart 90 days after implantation. The other 20 patients died during mechanical support because their condition could not be stabilized for transplantation, despite blood flow restoration. Fifty-six percent of the patients younger than 40 years underwent successful transplantation and six of nine patients are long-term survivors. By comparison, in the older group, 17.6% of patients underwent transplantation and one of three survived long term. Forty-four percent of patients in the acute decompensation group had successful transplantation and four of seven patients are long-term survivors. In the chronic decompensation group these figures were 29.4% and three of five patients. All patients who were heavily immunosuppressed (n = 4) died of sepsis. Transplantation was considered and performed only when the patient's condition was correct and stable. In six patients an infection developed in the immediate posttransplant period. Three of the infections were resolved with antibiotic therapy. One originated in the mediastinum and is still unresolved, although the patient's condition is improving. Another patient died of an anoxic coma caused by ventilatory problems. There were two late deaths at 14 and 19 months, one resulting from a combination of toxoplasmosis and rejection and the other from a Kaposi sarcoma caused by azathioprine treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗