PubMed Health⌕ Search

Biomedical subjects

N Benhaiem

Publications and source records attributed to N Benhaiem.

16 recordsLinked to original sources
PubMed1992

Effects of time and previous acute rejection episodes on coronary vascular reserve in human heart transplant recipients.

OBJECTIVES: This study examined whether previous rejection episodes may have deleterious effects on coronary vascular reserve of heart transplant recipients months after transplantation. BACKGROUND: Coronary reserve has been demonstrated to be within the normal range in long-term transplant patients without previous episodes of rejection. Conversely, acute rejection is associated with a dramatic reduction of coronary reserve, which is rapidly restored after therapy. METHODS: Coronary flow velocity was measured by intracoronary Doppler catheter before and after a maximally vasodilating dose of intracoronary papaverine in 16 control subjects and in 59 transplant patients classified into three groups with respect to time after transplantation: 1 to 6 months (group 1, n = 17), 7 to 18 months (group 2, n = 22) and > 18 months (group 3, n = 20). Coronary vascular reserve was evaluated through peak/rest coronary flow velocity ratio and minimal coronary vascular resistance index. All patients had normal findings on left ventricular angiography and coronary arteriography and a normal left ventricular mass. RESULTS: Arterial pressure was normal in all groups. Heart rate in the three groups of transplant patients, mean aortic pressure in groups 1 and 2, left ventricular systolic pressure in group 2 and rate-pressure product in groups 1 and 2 were higher than in control subjects. Average number of rejection episodes per patient was similar in the three groups of patients (group 1, 2.4 +/- 1.4; group 2, 2.5 +/- 1.9, and group 3, 2.1 +/- 1.3). Results showed no difference between each group of transplant patients and control subjects for peak/rest coronary flow velocity ratio (control subjects, 5.2 +/- 0.8; group 1, 5.3 +/- 1.5; group 2, 4.9 +/- 1.2, and group 3, 4.4 +/- 1.6) and for minimal coronary vascular resistance index (control subjects, 0.18 +/- 0.03; group 1, 0.18 +/- 0.04; group 2, 0.20 +/- 0.06, group 3, 0.23 +/- 0.11). In addition, patients with zero or one rejection episode had similar values of peak/rest coronary flow velocity ratio and minimal coronary vascular resistance index (4.3 +/- 1.3 and 0.23 +/- 0.10, respectively, n = 22) as did those with one or two rejection episodes (5.1 +/- 1.5 and 0.19 +/- 0.07, respectively, n = 24), and those with four or more episodes (5.2 +/- 1.4 and 0.19 +/- 0.05, respectively, n = 13). CONCLUSIONS: This study showed that coronary vascular reserve remains within normal range and is independent from the number of previous episodes of rejection until late after transplantation in human heart transplant patients with angiographically normal coronary arteries.

Analysis of Variance↗
PubMed1989

Severe impairment of coronary reserve during rejection in patients with orthotopic heart transplant.

The present study analyzed coronary sinus blood flow alterations after dipyridamole induced coronary vasodilation in seven patients whose endomyocardial biopsies evidenced no sign of rejection (group 1) and in five patients with histologic signs of rejection (group 2) after orthotopic heart transplantation. All patients were treated with cyclosporine and prednisone and some with azathioprine and had normal coronary arteriograms. Coronary sinus blood flow and coronary resistance were measured before and after intravenous dipyridamole (0.18 mg/kg/min over 4 minutes). Basal values were similar in groups 1 and 2 for coronary sinus blood flow (166 +/- 34 compared with 181 +/- 39 ml/min, respectively), coronary resistance (0.62 +/- 10 compared with 0.52 +/- 13 mm Hg/ml/min, respectively), coronary sinus blood oxygen content (5.7 +/- 1.6 compared with 4.5 +/- 0.9 ml/100 ml, respectively) and arterial-coronary sinus blood oxygen difference (10.6 +/- 1.3 compared with 10.3 +/- 1.8 ml/100 ml, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗
PubMed1987

Vertebral hemangiomas presenting with neurologic symptoms.

Six cases of spinal hemangiomas with neurologic symptoms are reported. In three of them the diagnosis was obtained before surgery using plain x-rays and spinal computed tomography scan or biopsy. In the other cases the diagnosis was not done before surgery. In two cases preoperative embolization had minimized blood loss during surgery. Laminectomy was performed in three cases. Large removal and/or vertebrectomy was carried out in the other cases. Our results and a review of the literature about the investigations and treatment of vertebral hemangiomas led us to propose a stereotypical management of spinal hemangiomas with neurologic symptoms.

Adolescent↗
PubMed1986

[Arterial recanalization using the laser. A technic for the future?].

On the basis of two years' experience, a technique for the use of percutaneous endoluminal continuous emission Nd-YAG laser has been developed for arterial recanalisation. The effectiveness of this type of laser has been demonstrated in a large number of clots and atheromatous plaques, including calcified plaques. A balloon catheter gives a coaxial position of the fiber in center of the artery. Infusion of a blood solution containing 3 g of haemoglobin/100 ml at a rate of 20 ml/minute limits the thermal parietal lesions, improves the conditions of laser treatment and eliminates any risk of arterial perforation. No embolic debris is collected down-stream. Recanalisation of long arterial segments in amputated legs was performed prior to the human application. Ten patients have been treated with no mortality and virtually no morbidity. The narrowness of the reformed arterial lumina resulted in early re-thrombosis in the first 5 cases, requiring balloon modelling to ensure patency with a follow-up of 1 to 3 months in the 5 following patients.

Aged↗
PubMed1985

[Arterial disobliteration by the laser].

In order to determine the optimal conditions for disobliteration of occluded arteries without damaging the arterial wall, the effects of a Nd-YAG laser connected to a 0.2 mm diameter fibre optic system were studied on post-mortem coronary arteries and popliteal and tibial arteries of amputated limbs. Vaporisation of atheromatous plaques was consistently obtained with energies of 300 to 600 joules associated with perfusion of the vessel with dilated blood (3 g/100 ml of haemoglobin) at a flow rate of 20 ml/min. Protection of the arterial wall was ensured by introducing the fibre aortic system through a balloon catheter and by cooling with the perfusion liquid. The reproducibity of these results in the absence of major arterial wall damage, and the facility of manipulation of the fibre optic system due to its flexibility and narrow diameter, encouraged us to use this method clinically. The first three applications on peripheral arteries (femoral and popliteal arteries) confirmed that this method of arterial disobliteration can be used with a certain degree of efficacy with only a slight risk of arterial perforation. Further studies are essential to improve the degree of laser penetration of the arterial obstruction and to increase the diameter of the tunnel of recanalisation.

Arterial Occlusive Diseases↗
PubMed1984

Recanalization of human arteries using Nd-YAG laser carried by optical fibre.

Nd-NAG laser carried by optical fibres 0.2 mm diameter was used in experimental studies to recanalize obstructed human cadaver arteries. Successful perforation of atheromatous plaques was obtained in all cases with a power of 12 W and a duration of exposure of 30-50 s provided that blood and not saline was used. The arterial wall was protected from injury by coaxial position of the optical fibre that was inserted into an inflated balloon catheter, and by circulating blood that cooled the system. The feasibility of guiding these devices in man was demonstrated in femoral and coronary arteries.

Arterial Occlusive Diseases↗
PubMed1984

Conditions for effective Nd-YAG laser angioplasty.

To establish the optimal conditions for recanalisation of obstructed arteries without damage to vessel walls, a Nd-YAG laser coupled to a 0.2 mm diameter optic fibre was used on obstructed human cadaver coronary and peripheral arteries and on popliteal arteries in amputated limbs. Vaporization of atheromatous plaques was consistently obtained with an energy of 360-600 J and a diluted blood perfusate (3 g/100 ml haemoglobin) at a rate of 20 ml/min. The arterial wall was protected from thermal injury by inserting the optic fibre into an inflated balloon catheter and by cooling the system with the perfusate. Since recanalisation of occluded arteries was consistently obtained without damage to the arterial wall or debris and thin and flexible optic fibres were easy to guide in the arteries, percutaneous transluminal Nd-YAG laser angioplasty was used in obstructed femoral and popliteal arteries in three patients. The first European trials in man showed the method to be feasible, effective, and harmless, although further studies are required to improve penetration of the obstruction and increase the diameter of tunnel.

Angioplasty, Balloon↗
PubMed1984

[Effects of the laser on atheroma plaques].

Effects of laser radiation on atherosclerotic plaques were evaluated in vitro and in vivo. Necropsy artherosclerotic femoral and coronary arteries were submitted to a laser beam. Arteries were perfused by saline or blood solution and a silicone fibro-optic system was placed near the plaques through a balloon dilatation catheter. After laser radiation (20 to 40 W, 2 to 10 seconds) angiograms and histologic sections were obtained. Aorta of 20 atherosclerotic New Zealand rabbits was exposed in dry condition to a CO2 laser beam (2-4 W, 0,2 second). After reinstatement of blood flow, animals were sacrificed from 24 hours to 3 weeks for microscopical examination. In vitro studies showed a significant recanalisation of the thrombosed arteries under blood flow but not under saline solution. Histologically the laser radiation produced a crater surrounded by thermal intimal damage and decollated calcified plaques. In vivo studies showed the healing process: no perforation, no aneurysm, no thrombosis occurred. After 24 hours the crater was filled with a non extensive thrombus, on the first week the thrombus contained phagocyte cells and on the third week, the endothelial damage was completely healed. These results suggest that laser radiation may be effective to recanalize totally occluded arteries in human.

Animals↗
PubMed1983

Arteriovenous fistulae of the meninges draining into the spinal veins. A histological study of 28 cases.

The histological study of 28 cases of arteriovenous fistulae of the meninges draining into spinal veins, previously known as retromedullary arteriovenous malformations, has shown that the shunt is located inside the thickness of the dura mater. It is fed by a normal artery and drains through a single and abnormal vein. Our histological documents lead us to the conclusion that this entity is not a genuine arteriovenous malformation but, in all probability, an acquired lesion.

Adult↗
PubMed1979

[Cardiac localization of Hodgkin's disease (author's transl)].

Two cases of specific cardiac affection during the course of Hodgkin's disease, of which one involved all three layers, illustrate the diagnostic difficulties in such cases. These are related to the latency period before clinical manifestations appear and the more frequent possibility of iatrogenic affection, especially during treatment with adriamycin and/or radiotherapy. Surgical biopsy of the pericardium is essential for establishing the diagnosis and prescribing treatment, the results of which are often satisfactory.

Adult↗
PubMed1978

[Vasodilator treatment of the acute phase of myocardial infarct with phentolamine. Analysis of hemodynamic results and therapeutic indications].

Treatment by phentolamine was carried out in 30 patients presenting with an acute myocardial infarction complicated by left ventricular failure, 8 of which had cardiogenic shock. The response to treatment was closely related to the level of overload of the left ventricle. Significant improvement in the haemodynamic state was only observed in the most severe cases of cardiac failure, and in these cases was accompanied by only a minimal and insignificant change in mean arterial pressure and heart rate.

Acute Disease↗
PubMedDate not supplied

Late occlusion of aorto-bifemoral grafts. Causes and management.

Late occlusion occurred in 52 limbs of 37 bifurcated aorto-femoral grafts (37 patients). These were analysed to determine causal factors and the efficacy of various surgical techniques of repair. There were two principle causes: intimal hyperplasia (n = 19) and progressive atherosclerosis (n = 18), and then miscellaneous causes (n = 15). Surgical techniques included: repair of inflow by thrombectomy (n = 30), new aorto-femoral graft (n = 6), cross-over femoro-femoral (n = 3), and axillo-bifemoral graft (n = 2); repair of out-flow by profundoplasty (n = 18), addition of a new length of graft (n = 10), and femoro-popliteal bypass (n = 13). There were no immediate post-operative deaths but four rethromboses (7.6%) occurred and there were five amputations (9.6%). During the follow-up period (mean 19 months), four patients died (11%), 5 limbs reoccluded (9.4%), and two were amputated (4.2%). Patency rate was 90% for thrombectomy and 83% for new aorto-bifemoral graft. It was 86% for repair of the profunda femoris artery and 77% for femoro-popliteal bypass. Although no statistical analysis can be applied on this small number of patients, the present study suggests that: intimal hyperplasia is a frequent and probably under-estimated cause of late thrombosis; whenever feasible thrombectomy and profundoplasty are the most simple and effective procedure of repair.

Adult↗