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Jean-Michel Correas

Publications and source records attributed to Jean-Michel Correas.

14 recordsLinked to original sources
PubMed2026

Type, severity, frequency and management of adverse reactions associated with ultrasound contrast agents: a systematic review and meta-analysis.

OBJECTIVES: This systematic review and meta-analysis are aimed at evaluating the incidence of adverse drug reactions (ADRs) following administration of clinically approved ultrasound contrast agents (UCAs) in adults and children, to assess risks in patients with cardiovascular disease and in pregnancy, and to evaluate the effectiveness of emergency management of severe ADRs. MATERIALS AND METHODS: A PRISMA 2020 systematic review was conducted searching PubMed, Scopus, and Embase. Two reviewers independently screened, extracted data, and assessed quality. Incidence estimates were pooled when feasible, stratified by age group, contrast agent, and administration route. RESULTS: Seventy-four studies encompassing >&#x2009;1 million adults and >&#x2009;36,000 children were included, contributing multiple analytic cohorts to the quantitative synthesis. Severe acute ADRs were extremely rare (6 and 16 cases per 100,000 in adults and children, respectively) and absent following endocavitary administration in children. Non-severe acute ADRs occurred in 11 and 8 cases per 10,000 adults and children, respectively. Delayed reactions were very rare (<&#x2009;1 case per million in adults). No significant safety differences emerged between UCA products. The incidence of ADRs in patients with cardiovascular disease was analogous to the general population. No ADRs were reported in pregnant women. Standard emergency management was effective in almost all serious cases, though rare fatalities occurred. CONCLUSION: UCAs show an excellent safety profile in adults and children, with very rare severe ADRs and few non-severe, typically self-limiting reactions. Strict adherence to recommended emergency management protocols mitigates the remaining risks, supporting safe use across a broad range of clinical indications. PROSPERO REGISTRATION: CRD42023432668. KEY POINTS: Question What is the incidence, type, and severity of acute and delayed ADRs associated with clinically approved UCAs across different patient populations? Findings Severe acute adverse reactions are very rare, and non-severe reactions are rare and self-limiting, with no significant safety differences between adults, children, or patients with cardiovascular disease. Clinical relevant UCAs show an excellent safety profile across populations. These findings support their safe clinical use as reliable alternatives to iodine-based and gadolinium-based contrast agents in routine diagnostic imaging.

Contrast Media↗
PubMed2006

The kidney: imaging with microbubble contrast agents.

Conventional ultrasonography of the kidney is faced by limitations due to the poor contrast of B-mode imaging for parenchymal disease and limited sensitivity of color Doppler for the detection of intracortical capillaries and deep pedicular vessels. Ultrasound contrast agents (USCAs) overcome these limitations, allowing the development of new applications for renal blood flow imaging and quantification. These improvements result from the increased acoustic response obtained from the microbubbles, as well as from the development of pulse sequences for bubble-specific imaging. In radiology, the liver has been considered as the primary target for contrast because USCAs allow both detection and characterization of focal lesions. The kidney has been less studied because USCA kinetics do not provide the same obvious potential for tumor characterization, and most clinical trials for contrast-enhanced renal imaging were conducted using color Doppler. Despite this, the kidney offers promising applications as USCAs improve the detection of abnormal microvascular and macrovascular disorders. Contrast-enhanced US may become the modality of choice for diagnosis of renal artery stenosis and detection of a perfusion deficit, as well as for characterization of indeterminate renal lesions, atypical cystic lesions, and the identification of acute pyelonephritis.

Contrast Media↗
PubMed2006

[Conservative treatment of kidney cancer by cryoablation and radiofrequency].

Cryoablation and radiofrequency are minimally invasive techniques allowing resection of the tumour by application of physical means (cold or heat) to the centre of the lesion, rather than strictly surgical resection. The incision is usually percutaneous but can be laparoscopic in certain indications. Indications are currently limited to exophytic renal tumours < 40 mm, situated away from structures of the hilum (vessels and renal pelvis) and gastrointestinal structures in patients > 70 years or in the context of previously operated hereditary renal carcinoma (von Hippel Lindau disease). The results of the first series are encouraging, although more contradictory for radiofrequency probably due to the heterogeneous equipment (electrodes, generator, frequency, etc.). The complication rate is low. A PHRC national multicentre randomized study is currently underway to compare the functional and oncological results of radiofrequency and conservative surgery.

Catheter Ablation↗
PubMed2005

Ex vivo perfusion of human spleens maintains clearing and processing functions.

The spleen plays a central role in the pathophysiology of several potentially severe diseases such as inherited red cell membrane disorders, hemolytic anemias, and malaria. Research on these diseases is hampered by ethical constraints that limit human spleen tissue explorations. We identified a surgical situation--left splenopancreatectomy for benign pancreas tumors--allowing spleen retrieval at no risk for patients. Ex vivo perfusion of retrieved intact spleens for 4 to 6 hours maintained a preserved parenchymal structure, vascular flow, and metabolic activity. Function preservation was assessed by testing the ability of isolated-perfused spleens to retain Plasmodium falciparum-infected erythrocytes preexposed to the antimalarial drug artesunate (Art-iRBCs). More than 95% of Art-iRBCs were cleared from the perfusate in 2 hours. At each transit through isolated-perfused spleens, parasite remnants were removed from 0.2% to 0.23% of Art-iRBCs, a proportion consistent with the 0.02% to 1% pitting rate previously established in artesunate-treated patients. Histologic analysis showed that more than 90% of Art-iRBCs were retained and processed in the red pulp, providing the first direct evidence of a zone-dependent parasite clearance by the human spleen. Human-specific physiologic or pathophysiologic mechanisms involving clearing or processing functions of the spleen can now be experimentally explored in a human tissue context.

Animals↗
PubMed2004

Genotype-phenotype correlation in von Hippel-Lindau families with renal lesions.

von Hippel-Lindau (VHL) disease arises from mutations in the VHL gene and predisposes patients to develop a variety of tumors in different organs. In the kidney, single or multiple cysts and renal cell carcinomas (RCC) may occur. Both inter- and intrafamilial heterogeneity in clinical expression are well recognized. To identify VHL-dependent genetic factors, we investigated the renal phenotype in 274 individuals from 126 unrelated VHL families in whom 92 different VHL mutations were characterized. The incidence of renal involvement was increased in families with mutations leading to truncated protein (MLTP) or large rearrangement, as compared to families with missense changes (81 vs. 63%, respectively; P=0.03). In the latter group, we identified two mutation cluster regions (MCRs) associated with a high risk of harboring renal lesions: MCR-1 (codons 74-90) and MCR-2 (codons 130-136). In addition, the incidence of RCC was higher in families with MLTP than in families with missense changes (75 vs. 57%; P=0.04). Furthermore, mutations within MCR-1 but not MCR-2 conferred genetic susceptibility to develop RCC. Overall, our data argued for a substantial contribution of the genetic change in the VHL gene to susceptibility to renal phenotype in VHL patients.

Adult↗
PubMed2004

Lymphocytic hypophysitis with lachrymal, salivary and thyroid gland involvement.

We report on hypophysitis associated with a prominent lymphoid infiltration of salivary and lachrymal glands in a 35-year-old woman with a dramatic response to steroids. Four years later, overt Graves' disease developed. To our knowledge, pseudotumoral lymphocytic infiltration of both lachrymal and salivary glands has never been described in association with hypophysitis. Benign lymphocytic hypophysitis may belong to a spectrum that extends from low-grade lymphoid proliferation to autoimmune disease. Such a process may follow a regional tissue distribution including pituitary, thyroid, lachrymal and salivary glands.

Journal Article↗
PubMed2003

Blood flow quantification with contrast-enhanced US: "entrance in the section" phenomenon--phantom and rabbit study.

PURPOSE: To investigate changes in destruction-replenishment curves (in vitro and in vivo) that result from microbubble destruction in feeding vessels that pass through the imaging plane before microbubbles enter the region of interest (ROI). MATERIALS AND METHODS: During continuous injections of an ultrasonographic contrast agent, nonlinear gray-scale images were obtained in vitro in the longitudinal plane of a renal dialysis cartridge flow phantom (flow rates of 100, 200, and 400 mL/min) and in vivo in the coronal plane of the left kidneys of two rabbits (two kidneys). Destruction-replenishment curves were obtained for the dialysis cartridge in ROIs located immediately after the entrance of the microbubbles into the image plane and further from the entrance, after microbubbles had traveled across the complete length of the imaging plane. Replenishment curves were also obtained from ROIs in the rabbit kidneys at the level of segmental arteries, distal interlobar arteries, and the cortex. RESULTS: The ROIs immediately after the entrance of the microbubbles in the image plane of the dialysis cartridge and in the segmental artery of the kidney followed a typical exponential function, A(1 - e-alphat). Early portions of curves obtained in ROIs filled with microbubbles that had already passed through the image plane of the dialysis cartridge or in the renal cortex were not well described by such a function. The shape of the curve and the variations as a function of flow rate can be explained by means of a mathematical model based on indicator-dilution theory. CONCLUSION: When the feeding vessels of an ROI travel across the ultrasound field before they reach the measurement region, the typical shape of the replenishment curve is modified (reduced velocity parameter and plateau).

Animals↗
PubMed2003

Improved detection of hepatic metastases with pulse-inversion US during the liver-specific phase of SHU 508A: multicenter study.

PURPOSE: To compare conventional B-mode ultrasonography (US) alone with the combination of conventional B-mode US and contrast material-enhanced (SHU 508A) late-phase pulse-inversion US for the detection of hepatic metastases by using dual-phase spiral computed tomography (CT) as the standard of reference. MATERIALS AND METHODS: One hundred twenty-three patients underwent conventional US, US in the liver-specific phase of SHU 508A, and single-section spiral CT. US and CT images were assessed by blinded readers. Differences in sensitivity, specificity, and the number and smallest size of metastases at conventional and contrast-enhanced US were compared by using CT as the standard of reference. Lesion conspicuity was assessed objectively (quantitatively) and subjectively by one reader before and after contrast material administration. RESULTS: In 45 of 80 (56%) patients with metastases, more metastases were seen at contrast-enhanced US than at conventional US. In three of these patients, conventional US images appeared normal. The addition of contrast-enhanced US improved sensitivity for the detection of individual metastases from 71% to 87% (P <.001). On a patient basis, sensitivity improved from 94% to 98% (P =.44), and specificity improved from 60% to 88% (P <.01). Contrast enhancement improved the subjective conspicuity of metastases in 66 of 75 (88%) patients and the objective contrast by a mean of 10.8 dB (P <.001). Contrast-enhanced US showed more metastases than did CT in seven patients, and CT showed more than did contrast-enhanced US in one of 22 patients in whom an independent reference (magnetic resonance imaging, intraoperative US, or pathologic findings) was available. CONCLUSION: Contrast-enhanced US improved sensitivity and specificity in the detection of hepatic metastases.

Adolescent↗
PubMed2002

Diagnosis of pheochromocytoma and laparoscopic adrenalectomy in two anephric patients with von Hippel-Lindau disease.

This study reports the first two cases of laparoscopic treatment of functional pheochromocytomas in patients with von Hippel-Lindau (VHL) disease receiving regular dialysis treatment. The genetic changes predisposing to pheochromocytoma, diagnostic procedures, and surgical management were analyzed. Both patients were considered at low risk of developing pheochromocytoma because they belonged to VHL families with 10 and 25 affected relatives without pheochromocytoma (VHL type 1 families). The mutation responsible for the disease was a stop codon in one case and a missense change in the other. Multiple renal cell carcinomas had required removal of the kidneys at age 37 in one patient and age 25 in the other patient. Computed tomography scan was crucial for diagnosis, showing a unilateral enlarged adrenal gland after 3 and 6 years on regular dialysis. No change in blood pressure was observed. MIBG scintigraphy was negative. Plasma epinephrine in one case and dopamine in the other were increased compared with patients on hemodialysis without pheochromocytoma. Pheochromocytomas were removed successfully by laparoscopic adrenalectomy. Lifelong follow-up of all affected tissues is required in all VHL patients, and pheochromocytoma should be screened for even in the absence of family history in large kindreds. Computed tomography scan allows early recognition, and patients on hemodialysis are responsive to laparoscopic adrenalectomy.

Adrenal Gland Neoplasms↗
PubMed2002

Optimizing an ultrasound contrast agent's stability using in vitro attenuation measurements.

RATIONALE AND OBJECTIVES: To evaluate the changes in the microbubble population of a currently available ultrasound contrast agent (USCA) through attenuation measurements to optimize its clinical use. MATERIALS AND METHODS: The microbubble population from a galactose-based USCA (Levovist, Schering AG, Germany) was characterized in vitro using attenuation measurements. The effect of dose (0.1, 0.5, and 1 mL), concentrations (200, 300, and 400 mg mL(-1)) and time since reconstitution (2, 12, 22, and 32 minutes) was evaluated using two broadband pulses at different peak negative pressures (0.39 and 0.49 MPa) for a total of 72 injections. RESULTS: Two minutes after reconstitution, a linear relationship was found between attenuation measurements and the amount of USCA (slope 0.92 dB x mg x cm(-1) ml(-1), R = 0.86). For a given dose and concentration, the microbubble stability was significantly reduced with the increase of the time since reconstitution, particularly for the lower concentrations. CONCLUSIONS: The persistence and contrast effect of Levovist can be improved by using recommended minimum time since reconstitution and maximum concentration.

Contrast Media↗