Assessment of a percutaneous iliosacral screw insertion simulator.

International audienceBACKGROUND: Navigational simulator use for specialized training purposes is rather uncommon in orthopaedic and trauma surgery. However, it reveals providing a valuable tool to train orthopaedic surgeons and help them to plan complex surgical procedures. PURPOSE: This work's objective was to assess educational efficiency of a path simulator under fluoroscopic guidance applied to sacroiliac joint percutaneous screw fixation. MATERIALS AND METHODS: We evaluated 23 surgeons' accuracy inserting a guide-wire in a human cadaver experiment, following a pre-established procedure. These medical trainees were defined in three prospective respects: novice or skilled; with or without theoretical knowledge; with or without surgical procedure familiarity. Analysed criteria for each tested surgeon included the number of intraoperative X-rays taken in order to achieve the surgical procedure as well as an iatrogenic index reflecting the surgeon's ability to detect any hazardous trajectory at the time of performing said procedure. RESULTS: An average number of 13 X-rays was required for wire implantation by the G1 group. G2 group, assisted by the simulator use, required an average of 10 X-rays. A substantial difference was especially observed within the novice sub-group (N), with an average of 12.75 X-rays for the G1 category and an average of 8.5 X-rays for the G2 category. As far as the iatrogenic index is concerned, we were unable to observe any significant difference between the groups

In vivo evaluation of a hybrid nanoparticle for molecular imaging of amyloid aggregation

International audienceAmyloid-β (Aβ) fibrillization is described as a central event in the pathogenesis of Alzheimer’s disease (AD). Amyloid imaging is expected to play a pivotal role in early and differential diagnosis of dementias, and in the evaluation of anti-Aβ treatments. Luminescent conjugated oligothiophenes (LCO) have been proposed as optical biomarkers of protein fibrillation [1]. In this paper, we evaluated a fluorescent magnetic hybrid nanoprobe (HNP5011), based on gadolinium fluoride nanoparticles functionalized with luminescent conjugated polythiophenes moieties (Fig. 1). The aim of this study was to investigate its potential for molecular imaging in a rat model bearing intracerebral pre-aggregated Aβ peptides

Évaluation initiale d'un environnement virtuel d'apprentissage des biopsies prostatiques

National audienceÉvaluation initiale d'un environnement virtuel d'apprentissage des biopsies prostatiques

Novel technology for learning in medicine

Kaléidoscop

Investigation of a fluorescent magnetic hybrid nanoprobe for stroke imaging

International audienceIntroduction In this paper, we introduce a fluorescent magnetic hybrid nanoprobe (5011), based on gadolinium fluoride nanoparticles functionalized with luminescent conjugated polythiophenes moieties (Fig 1). The aim of this study was to investigate its potential for molecular imaging in experimental stroke. Specifically, we aimed to test the hypothesis that 5011 may cross the disrupted blood-brain barrier (BBB) in the ischemic lesion. Methods Transient middle cerebral artery occlusion (tMCAO) was performed in 7 rats using the intraluminal model. In this model, mild BBB disruption was consistently shown at 3 days post-surgery (1). Therefore, dynamic MRI of the brain was performed 3 days post-tMCAO, before, during and after bolus injection of 5011 (N=6) or Gd-DOTA (N=1) both at 150 µmol Gd/kg (7T, TE/TR: 10.5/800-ms, flip angle 30°, 40 repetitions, one-hour acquisition). We used a model of focal BBB opening by heat injury (N=6) to ascertain that the MR sequence used was sensitive enough to detect contrast enhancement due to 5011 leakage through a severely disrupted BBB. Brains and livers of tMCAO rats were prepared either for biphotonic microscopy (N=3) or inductively coupled plasma-mass spectroscopy (ICP-MS, N=3). Results As expected in tMCAO rats, Gd-DOTA injection resulted in a significant enhancement of the ischemic lesion (22% compared to pre-contrast signal). In contrast, there was no signal enhancement difference between the ischemic lesion (-3±1%) and the contralateral region (-2±1%) in rats injected with 5011 (Fig 2A). Biphotonic microscopy showed sparse agglomerates of 5011 in the parenchyma of the ischemic lesion (Fig 2, insert). In the model of focal BBB opening, 5011 injection resulted in a significant enhancement of the lesion (13±3%) (Fig 2B). ICP-MS analyses are in progress. Conclusions Transport of 5011 across the disrupted BBB could be detected in tMCAO rats using a sensitive two-photon microscope but its accumulation was too low to be detected with MRI. Based on these results, we aim to functionalize the hybrid nanoprobe to target vascular adhesion molecules that are highly expressed after experimental stroke, rather than intraparenchymal (extravascular) targets

Investigation of a fluorescent magnetic hybrid nanoprobe for stroke imaging

International audienceIntroduction In this paper, we introduce a fluorescent magnetic hybrid nanoprobe (5011), based on gadolinium fluoride nanoparticles functionalized with luminescent conjugated polythiophenes moieties (Fig 1). The aim of this study was to investigate its potential for molecular imaging in experimental stroke. Specifically, we aimed to test the hypothesis that 5011 may cross the disrupted blood-brain barrier (BBB) in the ischemic lesion. Methods Transient middle cerebral artery occlusion (tMCAO) was performed in 7 rats using the intraluminal model. In this model, mild BBB disruption was consistently shown at 3 days post-surgery (1). Therefore, dynamic MRI of the brain was performed 3 days post-tMCAO, before, during and after bolus injection of 5011 (N=6) or Gd-DOTA (N=1) both at 150 µmol Gd/kg (7T, TE/TR: 10.5/800-ms, flip angle 30°, 40 repetitions, one-hour acquisition). We used a model of focal BBB opening by heat injury (N=6) to ascertain that the MR sequence used was sensitive enough to detect contrast enhancement due to 5011 leakage through a severely disrupted BBB. Brains and livers of tMCAO rats were prepared either for biphotonic microscopy (N=3) or inductively coupled plasma-mass spectroscopy (ICP-MS, N=3). Results As expected in tMCAO rats, Gd-DOTA injection resulted in a significant enhancement of the ischemic lesion (22% compared to pre-contrast signal). In contrast, there was no signal enhancement difference between the ischemic lesion (-3±1%) and the contralateral region (-2±1%) in rats injected with 5011 (Fig 2A). Biphotonic microscopy showed sparse agglomerates of 5011 in the parenchyma of the ischemic lesion (Fig 2, insert). In the model of focal BBB opening, 5011 injection resulted in a significant enhancement of the lesion (13±3%) (Fig 2B). ICP-MS analyses are in progress. Conclusions Transport of 5011 across the disrupted BBB could be detected in tMCAO rats using a sensitive two-photon microscope but its accumulation was too low to be detected with MRI. Based on these results, we aim to functionalize the hybrid nanoprobe to target vascular adhesion molecules that are highly expressed after experimental stroke, rather than intraparenchymal (extravascular) targets