Biomedical subjects

Frederic Prat

Publications and source records attributed to Frederic Prat.

3 recordsLinked to original sources

PubMed2006

The complementary Erlangen active simulator for interventional endoscopy training is superior to solely clinical education in endoscopic hemostasis--the French training project: a prospective trial.

BACKGROUND: The Erlangen Active Simulator for Interventional Endoscopy (EASIE) using ex-vivo porcine organs was introduced in 1997. The present study should analyze whether repeated EASIE simulator training in endoscopic hemostasis led to superior performance compared with a traditionally educated group. The results were compared with a similar project in New York. METHODS: Thirty-five French GI fellows were enrolled. Baseline skills evaluation was performed in four disciplines (manual skills, injection/coagulation, clip application and variceal ligation) using the compactEASIE-simulator equipped with an upper gastrointestinal organ package for bleeding simulation. The same, translated evaluation forms (from the prior New York project) were used. Subsequently, fellows were randomized into group A (n=17, only clinical education) and group B (n=18, additional three simulator trainings). Group B was trained the next day and after 4 and 7 months by experts of the French Society of Gastrointestinal Endoscopy. Both groups performed routine and emergency endoscopies at their home hospitals during the study period. Both groups were re-evaluated blindly after 9 months. RESULTS: The learning curve for group B showed a significant improvement in all disciplines (P<0.004) whereas group A improved significantly in only two of four disciplines at blinded final evaluation (manual skills P=0.02, injection/coagulation P=0.013). The direct comparison of groups B and A at blinded final evaluation showed significantly superior ratings for group B in all disciplines (P<0.006) and significantly shorter performance times in two disciplines (P=0.016 each). The comparison with the similar 'New York project' revealed that preexisting differences in skills were adjusted by the training. CONCLUSION: Complementary trainings (three workshops in 7 months) in endoscopic hemostasis using the compactEASIE improved skills compared with a solely clinical education. The results of the 'New York project' were confirmed and benefits were independent from the medical educational system.

Animals↗

PubMed2003

Transoesophageal ultrasound applicator for sector-based thermal ablation: first in vivo experiments.

New curative and palliative treatments must be proposed to respond to the bad long-term prognosis of oesophageal cancers. It has been demonstrated that high intensity ultrasound (US) can induce rapid, complete and well-defined coagulation necrosis. For the treatment of this cancer, we designed an applicator that uses an intraductal approach. The active part is an air-backed plane transducer. It has an external water-cooling system and operates at 10 MHz. Ex vivo experiments conducted on pig liver demonstrated the ability of this applicator to generate, by rotating the transducer, circular or sector-based coagulation necroses at predetermined depths up to 13 mm, with an excellent angular precision. The treatment of sector-based oesophageal tumours may be critical, where both malignant and healthy tissues are covered by the US beam. Thus, in vivo trials were conducted on five healthy pig oesophaguses to determine the maximal thermal dose that will not induce a perforation of the oesophagus or surrounding tissues. From the results of previous studies, this dose is high enough to treat pathological tissues. These promising results indicate that this US system represents a safe and effective tool for the clinical treatment of oesophageal tumours.

Animals↗

PubMed2002

Ultrasound cylindrical phased array for transoesophageal thermal therapy: initial studies.

This work was undertaken to investigate the feasibility of constructing a cylindrical phased array composed of 64 elements spread around the periphery (OD 10.6 mm) for transoesophageal ultrasound thermotherapy. The underlying operating principle of this applicator is to rotate a plane ultrasound beam electronically. For this purpose, eight adjacent transducers were successively excited with appropriate delay times so as to generate a plane wave. The exposure direction was changed by exciting a different set of eight elements. For these feasibility studies, we used a cylindrical prototype (OD 10.6 mm) composed of 16 elementary transducers distributed over a quarter of the cylinder, all operating at 4.55 MHz. The active part was mechanically reinforced by a rigid damper structure behind the transducers. It was shown that an ultrasound field similar to that emitted by a plane transducer could be generated. Ex vivo experiments on pig's liver demonstrated that the ultrasound beam could be accurately rotated to generate sector-based lesions to a suitable depth (up to 19 mm). Throughout these experiments, exposures lasting 20 s were delivered at an acoustic intensity of 17 W cm(-2). By varying the power from exposure to exposure, the depth of the lesion at different angles could be controlled.

Esophageal Neoplasms↗