Biomedical subjects

O Le Dref

Publications and source records attributed to O Le Dref.

23 records · Page 2Linked to original sources

PubMed1993

Limitation of vasodilation associated with warm heart operation by a "mini-cardioplegia" delivery technique.

Peripheral vasodilation is commonly seen during and after warm heart operations and can become of clinical concern when it requires vasopressors because some of these drugs adversely affect coronary artery bypass graft flows. As hemodilution lowers systemic vascular resistance, we assessed whether peripheral vasodilation could be limited by a drastic reduction of the volume of infused cardioplegia. Fifty patients underwent isolated coronary artery bypass grafting procedures using normothermic (35 degrees to 37 degrees C) bypass and normothermic continuous retrograde blood cardioplegia. They were divided into two equal groups: in group 1, blood was diluted 4:1 with hyperkalemic crystalloid cardioplegia, whereas in group 2, the cardioplegic "solution" was limited to the sole arresting agents that were concentrated in a small volume (16 mEq potassium chloride and 3 mEq magnesium chloride in a 20-mL ampoule). This "mini-cardioplegia" was continuously added to arterial blood so as to keep the heart arrested. The average volume of cardioplegia per patient was 1,000 mL in group 1 and 58 mL in group 2 (p < 0.0001). The mini-cardioplegia technique resulted in a reduced incidence of perioperative systemic vasodilation: group 2 patients required significantly less vasopressors (p < 0.05) and less volume loading, as reflected by significantly lower right atrial and pulmonary capillary wedge pressures (p < 0.05 and p < 0.03 at 12 hours postoperatively, respectively), compared with group 1 patients who received traditional high-volume cardioplegia. There were no differences between the two groups with respect to myocardial recovery, as assessed by standard clinical and hemodynamic end points.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1992

Improvement of digital coronary angiography: high resolution processing coupled with a real time functional synchronization procedure.

The use of Digital Subtraction Angiography in coronary applications is restricted by the difficulty in: 1. Obtaining a good resolution of the distal branches. 2. Avoiding, for the purpose of subtraction, the motion artifacts induced by artery and background displacement during the cardiac and respiratory cycles. 3. Preserving the dynamic vascular motion. 4. And storing the digital dynamic information on a permanent support. We used for this study an angiography system, based upon a high resolution 45 MIPS-32 Mbyte image processor, interfaced with a 2.75 Gbyte Winchester drive allowing the real time storage of either 30 frames/s in the 512*512*8 bits matrix or of 7.5 f/s in the 1024*1024*8 bits matrix. To preserve the most important dynamic informations on the basis of the 7.5 f/s maximal storage rate, we developed a synchronization device able to recognize in real time, from chronologic delays derived by using both ECG and Aortic Pressure curves, the functional End-Diastolic (ED) and the End-Systolic (ES) positions, even in the case of heart rates varying during the procedure. The ED and the ES images are stored together with the Mid-Systolic (MS), the 1/3-Diastolic (1/3D) and 2/3-Diastolic (2/3D) images. To establish the validity of this sampling method, which uses a reduced number of frames per cardiac cycle, 7200 coronary injections performed during 450 routine coronary angiographies were compared by two independent observers (A and B), using: first a Digital (D) 5 frames/cycle sequence, and secondly a cine Film (F) 50 frames/s sequence acquired immediately after the corresponding D injection. The D technique resulted in the best image and diagnostic quality, particularly when the F quality was estimated 'fair' or 'poor' by both observers, and in an important reduction on X-Ray doses. The visualisation of the sequential ED, MS, ES, 1/3D and 2/3D frames gives the possibility: 1. of saving the dynamic information, as a regular sample of functional images can be displayed with a cine loop technique. 2. of facilitating cardiac synchronized subtractions. 3. of reducing the amount of frames per cycle, thus allowing an important reduction of X-ray doses and the digital and permanent storage of the most important cardiac cycles.

Angiography, Digital Subtraction↗

PubMed1992

[Early constrictive pericarditis after coronary revascularization. Apropos of a case].

The authors report a case of severe constrictive pericarditis occurring 6 weeks after coronary bypass surgery and in the absence of any other predisposing factor. The diagnosis was confirmed by CT scan and cardiac catheterisation which showed signs of a diastole. The patient died despite early surgical reoperation because of the severity of the pericardial fibrosis.

Aged↗

PubMed1990

[Role of angioplasty in the treatment of arteritis of the lower limbs].

During the last ten years, the role of angioplasty in the management of peripheral vascular disease has considerably increased. Angioplasty requires a specific radiological equipment and qualified radiologist trained to this technics. The results depend mainly on the clinical, indication of angioplasty, on the importance and site of the lesion. The different reports give more or less the same rates of patency for stenosis or short occlusions: 80% for iliac arteries and 60% for femoral arteries within 3 years. The clinical benefit of angioplasty also depends the development of new atherosclerotic lesions. The new technics (laser, endoprosthesis) seems to be interesting for the prevention of restenosis. Their real place is still to be defined. The diversity of treatments for peripheral vascular diseases makes the collaboration of cardiologist, surgeon and interventional radiologist necessary for their management.

Angioplasty, Balloon↗

PubMedDate not supplied

Ovarian artery: angiographic appearance, embolization and relevance to uterine fibroid embolization.

PURPOSE: To describe the angiographic appearance of the ovarian artery and its main variations that may be relevant to uterine fibroid embolization. METHODS: The flush aortograms of 294 women who had been treated by uterine artery embolization for fibroids were reviewed. Significant arterial supply to the fibroid, and the origin and diameter of identified ovarian arteries were recorded. In patients with additional embolization of the ovarian artery, the follow-up evaluation also included hormonal levels and Doppler imaging of the ovaries. RESULTS: A total of 75 ovarian arteries were identified in 59 women (bilaterally in 16 women and unilaterally in 43 women). All ovarian arteries originated from the aorta below the level of the renal arteries with a characteristic tortuous course. Fifteen women had at least one enlarged ovarian artery supplying the fibroids. Fourteen women (14/15, 93%) presented at least one of the following factors: prior pelvic surgery, tubo-ovarian pathology or large fundal fibroids. CONCLUSION: We advocate the use of flush aortography in women with prior tubo-ovarian pathology or surgery or in cases of large fundal fibroids. In the case of an ovarian artery supply to the fibroids, superselective catheterization and embolization of the ovarian artery should be considered.

Adult↗