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Michel Vayssairat

Publications and source records attributed to Michel Vayssairat.

7 recordsLinked to original sources
PubMed2005

Urinary endothelin-1 as a marker of renal damage in sickle cell disease.

BACKGROUND: Sickle cell disease (SCD) affects the kidney by acute mechanisms as well as by insidious renal medullary/papillary necrosis, resulting in tubular defects, which increase the risk of dehydration and subsequent sickle crisis. Hypoxia has been reported to stimulate endothelin-1 (ET-1) synthesis by endothelial cells and also in the renal tubule. METHODS: This case-control study measured ET-1 in urine as a marker of its renal synthesis in asymptomatic SCD patients. Baseline plasma and urinary ET-1 levels were measured and followed during a water deprivation study and a subsequent administration of desmopressin. RESULTS: Urine and plasma levels of ET-1 were elevated in patients with SCD, compared with carefully matched African-French and African controls, and urine ET-1 excretion was associated with a marked urine-concentrating defect. Moreover, urinary ET-1 output was correlated with microalbuminuria in SCD patients. CONCLUSIONS: ET-1 is known to antagonize the tubular effects of vasopressin and to promote renal scarring; increased renal production of ET-1 could produce nephrogenic diabetes insipidus and dehydration in SCD patients through a combination of fibrosis and functional resistance to vasopressin. This study provides a rationale for trials with endothelin receptor antagonists in sickle cell disease nephropathy.

Adult↗
PubMed2003

Gadolinium-enhanced MR angiography as first-line preoperative imaging in high-risk patients with lower limb ischemia.

PURPOSE: To assess the clinical relevance of gadolinium-enhanced MR angiography (Gd-MRA) as the first-line angiographic examination for planning lower limb revascularization in patients at high risk of complications after contrast arteriography (CA). METHOD: Forty-five consecutive patients at high risk of post-CA complications because of chronic renal insufficiency, diabetes mellitus, advanced age, or the need for brachial artery catheterization or graft puncture had Gd-MRA as first-line angiography before a surgical or endovascular procedure for lower limb ischemia. RESULTS: After Gd-MRA, 59 procedures were performed, including 38 surgical reconstructions, 17 endovascular procedures, and four amputations. Complementary CA was only required in seven patients for whom a below-knee bypass was planned. Cumulative patency rates at 1 and 24 months were, respectively, 91% and 91% for suprainguinal bypasses, 100% and 92% for infrainguinal above-knee bypasses, 80% and 57% for below-knee bypasses, and 92% and 76% for iliofemoral angioplasties. After 24 months of follow-up, limb salvage, amputation, and mortality rates were, respectively, 86%, 3.5%, and 7% for stage II ischemia and 48%, 11%, and 30% for stages III and IV. CONCLUSION: Gd-MRA can be proposed for first-line preoperative imaging in the management of lower limb ischemia for patients at high risk and permits the selective use of CA as a second-line examination if a below-knee bypass is required.

Adult↗
PubMed2002

Why and how post-mastectomy edema should be quantified in patients with breast cancer.

In the present study, we advocate quantifying post-mastectomy edema in patients with breast cancer in millilitres and not in centimetre, contrarily to the usual routine practice. The water displacement and perimetric quantification methods exhibited both excellent reproducibility with an intraclass correlation coefficient > 0.99 and an accuracy coefficient < 0.3%.

Anthropometry↗
PubMed2002

Cutaneous microvascular blood flow and reactivity in patients with homozygous sickle cell anaemia.

Homozygous sickle cell anaemia (SS disease) involves a high prevalence of skin ulcerations, and background experience concerning the cutaneous microcirculatory flux and reactivity in this disease is very limited. We investigated, by laser-Doppler velocimetry, the microcirculatory cutaneous blood flow and vasoreactivity in 17 patients with SS disease but no cutaneous trophic changes, vs. the corresponding values in 18 normal matched controls. The laser-Doppler probe was placed on the foot dorsum, and recordings were made in the supine and dependent positions, and after post-ischaemic hyperaemia. The venoarteriolar reflex was calculated as the difference between the fluxes in the supine and dependent positions. In both positions, patients with SS disease exhibited clear vasodilation, with larger cutaneous fluxes than those of the controls (P=0.024 and 0.0009, respectively). The venoarteriolar reflex, expressed as a percentage of the resting supine flux, was lower in the patients (P=0.0004). These impairments of the microcirculatory fluxes, which combine a vasodilated state with abnormal vasoreactivity, resemble those observed in patients with chronic venous insufficiency and might be crucial in determining the pathogenesis of the skin ulcerations that occur in SS disease. Laser-Doppler velocimetry seems a suitable non-invasive technique for investigating such cutaneous microangiopathy.

Adolescent↗
PubMedDate not supplied

Foot gangrene in patients with end-stage renal disease: a case control study.

The prevalence of peripheral arterial disease (PAD) in patients with end-stage renal disease (ESRD) is high, with an annual risk of amputation estimated at 13%, and indications for limb revascularization in patients combining ESRD with stage IV PAD (foot gangrene) are still controversial. This case-controlled study compared survival, limb salvage, and quality of life in a group of patients hospitalized for foot gangrene according to their renal status (ESRD versus no renal insufficiency). All patients with ESRD hospitalized for foot gangrene (n = 16) from 1996 to 2002 were compared with a control group with normal creatininemia (n = 24) hospitalized for foot gangrene due to peripheral atherosclerotic arterial disease. The 2 groups were matched for age, sex ratio, and number with diabetes mellitus. After a mean follow-up of 467 +/-410 days, patients with ESRD had a more severe prognosis as regards mortality (68.7% vs 12.5%, p = 0.0005) and major amputation (31% versus 8%, p = 0.09). The ESRD group was characterized by more frequent extensive arterial calcifications (16/16 vs 13/24, p = 0.002), owing to a higher level of the calcium phosphorus product (3.54 +/-1.2 vs 2.4 +/-0.6, p = 0.0023), and by impaired microcirculatory perfusion, as indicated by a lower oxygen pressure (TcPO(2)) (15.6 +/-12 mm Hg vs 26 +/-16, p = 0.07). ESRD implies a poor prognosis in patients with stage IV peripheral arterial disease.

Aged↗