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R Limet

Publications and source records attributed to R Limet.

At least 73 records · Page 4Linked to original sources
PubMed2001

[Shone's syndrome: report of four cases and review of the literature].

The observation of four clinical cases of Shone's complex, two of them presenting first with predominant coarctation of the aorta, prompted us to review the pertinent literature. Patients with multiobstructive lesions of the left heart, including Shone's complex, represent a surgical challenge where the adequate management of mitral valve anomalies, subaortic stenosis, and coarctation constitutes the key prognostic factor for satisfactory mid-term outcome.

Aortic Coarctation↗
PubMed2001

[Resurgence of vein perforation surgery: SEPS (subfacial endoscopic perforator surgery)].

The treatment of venous ulcers is a challenge even in this era of modern medicine. The role of incompetent perforating veins in the pathophysiology of venous ulcers has been well documented. Open surgical interruption of incompetent perforating veins (Linton's procedure) may be complicated by important wound healing problems, and has never gained widespread acceptance as a first choice treatment. Recently, an endoscopic technique of subfascial interruption of perforating veins has been developed. This new procedure, with smaller scars and faster recovery, gives promising midterm results. The authors summarize their initial experience with subfascial endoscopic perforating surgery (SEPS) during the last three years (25 cases). They obtained ulcer healing in all cases. At 16 month follow-up, 88% of patients remain ulcer free. Three patients developed a new minor ulceration in the era of lipodermatosclerosis. This less invasive technique is a promising tool in the management of patients with venous ulcer disease.

Endoscopy↗
PubMed2001

[Should we correct stenosis of the superficial femoral artery in a patient with claudication?].

Infrainguinal arterial occlusive disease is very common at the age of 60 years or older. It remains often asymptomatic. In one third of cases, it results in claudication. Claudication is a benign symptom that rarely necessitates surgery or endovascular intervention. Physical training and control of risk factors are sufficient in most cases to improve the walking performance. Nowadays, the authors do no longer perform femoropopliteal bypass grafting as a first choice treatment for intermittent claudication. Conservative treatment has gained widespread acceptance for infrainguinal atherosclerosis with moderate ischemia. What is the fate of the claudicant? How effective is exercise therapy? Should we broaden the indications for percutaneous angioplasty? What is the place of femoropopliteal bypass graft for claudication? The authors investigate these different questions by means of an extensive review of recent literature. Based on this review and on international consensus documents, they justify their conservative approach to claudication secondary to occlusive disease of the superficial femoral artery.

Aged↗
PubMed2001

[Lung transplantation and mitochondrial function].

The mechanisms of cellular lesions induced by lung ischemia and reperfusion are not fully understood and, in particular, the consequences of pulmonary ischemia and reperfusion injury on mitochondrial function have not been previously investigated. Therefore, we studied the respiratory function of isolated pulmonary mitochondria in a swine model of lung ischemia and reperfusion. We demonstrated that prolonged hypothermic (4 degrees C) ischemia induces significant lesions of the mitochondrial respiratory chain, particularly if ischemia is followed by normothermic reperfusion. These results should be integrated in the cellular alterations induced by the ischemia-reperfusion injury. In another swine model mimicking controlled non-heart beating donors, we demonstrated that thirty minutes of cardiac arrest do not promote significant alteration of the mitochondrial respiratory function. In contrast, forty-five minutes of cardiac arrest, induced significant mitochondrial lesions. This pulmonary tolerance to normothermic cardiac arrest might be explained by the presence of air in the lung airways, allowing some aerobic metabolism after circulatory arrest. These results suggested that lung grafts might be harvested from non-heart beating donors after thirty minutes of cardiac arrest, significantly increasing the pulmonary graft pool.

Animals↗
PubMed2000

Evaluation of autoantibodies against oxidized LDL and antioxidant status in top soccer and basketball players after 4 months of competition.

Antioxidant status and titers of autoantibodies against oxidized low-density lipoproteins (ox-LDL-Ab) were investigated in top soccer (S; n = 21, age 24.6 +/- 4.3 years) and basketball (B; n 3,000 mIU/ml) in ox-LDL-Ab were found in half the players (12S and 4B) with a maximum reaching 6000 mIU/ml (normal range: 200-600 mIU/ml), showing an in vivo LDL oxidation. There was no correlation between ox-LDL-Ab titers and chlolesterol, LDL cholesterol, or antioxidant levels. Nevertheless, plasma vitamin C concentration was lower in athletes having high levels of ox-LDL-Ab when compared with those with normal levels (8.49 +/- 3.14 mirogram/ml vs. 10.39 +/- 2.55 microgram/ml), but this difference was not statistically significant. In conclusion, our data suggest that potential atherogenic and cardiovascular risks as reflected by high titers in ox-LDL-Ab may exist in some top athletes despite a nonaltered antioxidant status.

Adult↗
PubMed2000

Use of cryopreserved arterial homografts for management of infected prosthetic grafts: a multicentric study.

The objective of this study was to evaluate the effectiveness of cryopreserved arterial homografts for management of prosthetic graft infection. Between October 1992 and July 1998, 90 patients (84 men) with a mean age of 64 years from six different hospitals were treated for prosthesis infection by in situ replacement using a cryopreserved arterial homograft (CAH). In 43 patients (47%), the primary procedure had been performed at a nonparticipating center. Prosthetic graft infection occurred early (i.e., within 1 month after the primary procedure) in 15 cases and late in 75 cases. In the late group, the mean interval between the primary procedure and CAH replacement was 34 months (range, 3 to 330 months). In 41 patients, infection was located in the aortic region, including 17 presenting with enteroprosthetic fistula (EPF). In 49 patients, infection was confined to the femoral, popliteal, or subclavian region. Bacteriologic cultures were positive for one or more germs in 75 patients and negative in 15. The surgical procedure consisted of complete or partial removal of the infected prosthetic graft, debridement, and in situ reconstruction using one or more CAH. Our results showed that management of prosthetic graft infection, a grave complication, using a CAH is a promising technique, especially for patients in stable condition prior to reconstruction.

Adult↗
PubMed2000

Cytokine release and neutrophil activation are not prevented by heparin-coated circuits and aprotinin administration.

BACKGROUND: Cardiopulmonary bypass (CPB) initiates a whole-body inflammatory response where complement and neutrophil activation and cytokine release play an important role. This prospective trial examined the effects of both heparin-coated circuits and aprotinin on the inflammatory processes during CPB, with respect to cytokine release and neutrophil activation. METHODS: Two hundred patients undergoing cardiac surgery were randomized in four groups of 50 patients each: heparin-coated circuit with aprotinin (HCO-A) or without aprotinin (HCO) administration, and uncoated circuit with aprotinin (C-A) or without aprotinin administration (C). In groups receiving aprotinin, a high-dose regimen was given. In all groups, high initial doses of heparin were used (3 mg/kg intravenously). Tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and IL-8, and myeloperoxidase and elastase levels were measured in plasma samples taken before, during, and after CPB. RESULTS: In all groups, the TNF-alpha, IL-6, and IL-8 levels reached a maximum after protamine administration. After 24 hours, they remained significantly elevated (IL-6 and IL-8) or returned to baseline values (TNF-alpha). A similar pattern was observed with myeloperoxidase and elastase levels. No significant intergroup differences were observed. CONCLUSIONS: CPB is associated with cytokine release and neutrophil activation, which are not attenuated by the use of heparin-coated circuits or by the administration of aprotinin. Aprotinin and heparin-coated circuits do not show additive effects.

Aprotinin↗
PubMed2000

SMA circuits reduce platelet consumption and platelet factor release during cardiac surgery.

BACKGROUND: Platelet count and function are particularly damaged by cardiopulmonary bypass (CPB). This study evaluated the effects of a novel CPB circuit in terms of platelet count and activation, and postoperative need for blood products. METHODS: One hundred patients undergoing coronary grafting were randomized in two groups: control group (n = 50) and test group (n = 50, surface modifying additives circuit, SMA group). Blood samples were taken before, during, and after CPB. Postoperative blood loss, number of transfused blood products, and postoperative variables were recorded. RESULTS: The platelet count decreased less in the SMA group compared to the control group (end of CPB: respectively, 165 +/- 9 x 10(3)/mm3 vs 137 +/- 8 x 10(3)/mm3; p < 0.01). This was paralleled by a reduction in beta-thromboglobulin plasma levels in the SMA group. There was a trend to decreased blood loss in the SMA group, but the difference was significant only in patients taking aspirin preoperatively (p < 0.05). In the SMA group nearly 50% less fresh frozen plasma and platelet units were administered (p < 0.01). No operative deaths were observed. CONCLUSIONS: The use of circuits with surface additives is clinically safe, preserves platelet levels, and attenuates platelet activation. This may lead to a reduced need for blood products.

Adult↗
PubMed2000

Increased aortic compliance maintains left ventricular performance at lower energetic cost.

OBJECTIVE: The aim of this study was to investigate left ventricular contractility and energetic cost of cardiac ejection under conditions of acute increase in aortic compliance. METHODS: In six anaesthetized pigs, ascending aortic compliance was increased by adding a volume chamber in parallel to the ascending aorta. Systemic vascular parameters, including characteristic impedance, peripheral resistance, total vascular compliance, and inertance, were estimated with a four-element windkessel model. Arterial elastance was derived from these parameters. Left ventricular systolic function was assessed by end-systolic pressure-volume relationship (end-systolic elastance), and stroke work. Pressure-volume area was used as a measure of myocardial oxygen consumption. Heart rate remained constant during the experimentation. RESULTS: Adding the aortic volume chamber significantly increased vascular compliance from 0. 95+/-0.08 to 1.17+/-0.06 ml/mmHg (P<0.01), while inductance, characteristic impedance, peripheral resistance, and arterial elastance remained statistically at basal values, respectively 0. 0020+/-0.0003 mmHg.s(2)/ml, 0.105+/-0.009 mmHg.s/ml, 1.27+/-0.12 mmHg.s/ml, and 2.43+/-0.21 mmHg/ml. During the same interval, stroke work and pressure-volume area decreased respectively from 2700+/-242 to 2256+/-75 mmHg.ml (P<0.01), and from 3806+/-427 to 3179+/-167 mmHg.ml (P<0.01). Stroke work and pressure-volume area decreased at matched end-diastolic volumes. In contrast, end-systolic elastance, ejection fraction, and stroke volume remained statistically unchanged, respectively at 2.29+/-0.14 mmHg/ml, 48.1+/-2.1 %, and 32. 4+/-1.7 ml. CONCLUSIONS: These data suggest that, when facing an increased aortic compliance, the left ventricle displays unchanged contractility, but the energetic cost of cardiac ejection is significantly decreased. These data may be of clinical importance when choosing an artificial prosthesis for ascending aortic replacement.

Animals↗
PubMed2000

Heart graft monitoring by the ventricular evoked response.

Monitoring of the negative slew rate of the evoked T wave has been proposed as a noninvasive diagnostic tool to follow heart transplant recipients. The clinical contribution of this measurement on telemetrically recorded, paced unipolar ventricular electrograms was evaluated in the detection of grade 3 acute allograft rejection. Thirteen patients undergoing heart transplantation received a DDD pacemaker connected to two epimyocardial leads. Electrograms were recorded and digitized after each endomyocardial biopsy (EMB). The maximum slew rate of the descending slope of the repolarization phase (RSP) was extracted and normalized. A 20% downward shift of RSP from the reference value was considered abnormal. Results of signal processing were blinded during the first 6 months. Eleven patients completed the 6 months blinded period and two patients died. A total of 101 EMB were graded according to the International Society for Heart and Lung Transplantation classification. Grade 3 was assigned to 9 EMB. A significant difference was found between RSP values measured during grade 3 rejection episodes and other RSP values (P < 0.001). A diagnostic model consisting of a single threshold test confirmed the ability of RSP to predict significant signs of rejection on EMB (P < 0.0001). The sensitivity of RSP in detecting grade 3 rejections was 100%, specificity was 81%, negative predictive value 100%, and positive predictive value 35%. The use of RSP as a noninvasive monitoring tool to pose the indication for a biopsy would avoid 73% of EMB. Monitoring of transplanted hearts based on the analysis of the ventricular evoked response is promising and may markedly reduce the number of EMB.

Biopsy↗
PubMed2000

Ischaemic colitis following aortoiliac surgery.

Ischaemic colitis following aortoiliac surgery is a feared complication. Its frequency varies from 7% after repair of ruptured abdominal aortic aneurysm (AAA) to 0.6% after bypass for aortoiliac occlusive disease (AOD). In order to analyse predisposing factors and outcome of ischaemic colitis, the authors reviewed their clinical experience from 1988 to 1998. It concerns 28 cases (16 ruptured AAA, 7 elective AAA, 5 OAD) of clinically evident colonic ischaemia. This means an incidence of 7% after repair of ruptured AAA, 0.6% after elective AAA repair, and 0.8% after bypass for AOD. Transmural necrosis (grade 3) was observed in 21 patients, grade 2 ischaemia in 5 patients, and grade 1 ischaemia in 2 patients. Fifteen patients with grade 3 ischaemia underwent colectomy (Hartmann's procedure) with a mortality rate of 66%. All non operated grade 3 patients died. Overall, 16 of the 28 patients died at hospital (57% mortality rate). None of the patients with mild (grade 2 or 1) colonic ischaemia died. Profound hypovolaemic shock and inflammatory AAA were the only significant predisposing factors leading to colonic ischaemia. Associated colon revascularization could not avoid the evolution to colon necrosis in four patients. Reimplantation of a patent inferior mesenteric artery or an internal iliac artery was performed in only 4.8% of all aortoiliac reconstructions, and did not influence the development of ischaemic colitis. The authors conclude that a more liberal use of postoperative sigmoidoscopy could allow detecting colonic ischaemia at an earlier stage and reduce ensuing mortality. A reinforced effort to restore or preserve colonic vascularization could lower the incidence of colonic ischaemia following aortoiliac surgery.

Aged↗
PubMed2000

[Place of the Ross procedure (pulmonary autograft) in aortic valve surgery].

The pulmonary autograft operation consists of an aortic replacement using the autologous pulmonary valve. The pulmonary valve is substituted by a cryopreserved pulmonary homograft. This operation is in fact a delicate double valve replacement whose benefits are linked to the viability of the new aortic substitute. The pulmonary autograft has superb hemodynamic features and very low thrombogenicity. The report of a selected observation offers the occasion of defining the current indications of this operation in aortic valve surgery.

Aortic Valve↗
PubMed2000

[Surgery of the thymus gland, normal, atrophied or cancerous].

Thymoma is the most frequently resected mediastinal tumor. Its malignancy is related more to macroscopical findings than to microscopical analysis. All thymomas should be resected, in order to prevent malignant degeneration. Furthermore, for the treatment of myasthenia, several centers recommend resection of the thymus, either tumoral (thymoma) or atrophied. Although the role of surgery in this regard is controversial, all authors unanimously stress that complete resection of all thymic remnants is essential to achieve adequate results.

Atrophy↗
PubMed2000

[Extensions of mitral valve repair techniques: surgery for endocarditis and valvular tumors].

Mitral valve repair has demonstrated its superiority over valve replacement. Mitral valve repair constitutes the optimal therapeutic option in case of degenerative dystrophic, rheumatic, congenital or ischemic mitral valve disease. These surgical techniques can also be successfully and advantageously applied in case of bacterial endocarditis or tumoral valvular disease. We report a case of staphylococcal endocarditis and another case of posterior leaflet fibroelastoma to show the place of conservative mitral surgery in these unusual indications.

Adult↗