French mobile neurosurgical unit: a retrospective analysis of 22 years of mission.

INTRODUCTION: The French mobile neurosurgical unit (MNSU) is used to provide specific support to remote military medicosurgical units deployed in foreign theatres. If a neurosurgical casualty is present, the Role 2 team may request the MNSU to be deployed directly from France. The deployed neurosurgeon can then perform surgery in Role 2 or decide to evacuate the casualty and perform surgery in Role 4 in France. We provide an epidemiological analysis of MNSU missions between 2001 and 2023 and investigate the value of the MNSU for the French Armed Forces. METHODS: We conducted a retrospective case series that included patients managed by the MNSU from 1 January 2001 to 31 January 2023. We collected epidemiological data (eg, age, military or civilian status, delay between transmission and takeoff, origin of the injury and mission location), clinical records (aetiologies of the injury and disease), data on surgical intervention (operator nature and type of surgery) and data on postoperative outcomes recorded at the time of discharge from hospital. RESULTS: 51 patients were managed by the MNSU. 36 (70.5%) and 3 (5.8%) patients underwent surgery on Role 2 and Role 4, respectively. 39 (76.9%) interventions were due to traumatic injury, 4 (7.8%) due to hydrocephalus, 4 (7.8%) due to vascular causes, 3 (5.9%) due to tumour and 1 (2%) due to spine degeneration. In 30 (76.9%) of these cases, the first operator was a neurosurgeon from the MNSU, whereas in the remaining 9 (23.1%) cases, procedures were initially performed by a non-neurosurgeon. CONCLUSION: The MNSU contribution to D1 casualties' strategic evacuation (STRATEVAC) is important. The MNSU provides additional support for STRATEVAC during the reorganisation of French Armed Forces engaged in several fronts. With the return of high-intensity wars, the French MNSU must develop and adjust for the management of massive influxes of casualties.

Filter-less submicron hydrodynamic size sorting.

We propose a simple microfluidic device able to separate submicron particles (critical size ∼0.1 µm) from a complex sample with no filter (minimum channel dimension being 5 µm) by hydrodynamic filtration. A model taking into account the actual velocity profile and hydrodynamic resistances enables prediction of the chip sorting properties for any geometry. Two design families are studied to obtain (i) small sizes within minutes (low-aspect ratio, two-level chip) and (ii) micron-sized sorting with a µL flow rate (3D architecture based on lamination). We obtain quantitative agreement of sorting performances both with experiments and with numerical solving, and determine the limits of the approach. We therefore demonstrate a passive, filter-less sub-micron size sorting with a simple, robust, and easy to fabricate design.