Use of 3D-printing cerebral aneurysm model assisting microcatheter shaping in neurovascular intervention technique training.

BACKGROUND: Microcatheter shaping plays a vital role in coil embolization of cerebral aneurysms, while the complicated method and insufficient training opportunities make it difficult for junior neurovascular clinicians to master this technique. In this program, we constructed a novel training method and assessment system for microcatheter shaping in coil embolization of cerebral aneurysms with 3D technique, and evaluated its efficacy for microcatheter shaping training in junior neurovascular clinicians. METHODS: Patient-specific models for cerebral aneurysms in different locations and with different morphologies were selected by experienced senior neurovascular clinicians. The solid polylactic acid model and the soft hollow crystal silicone model of intracranial aneurysms were then made separately for shaping reference and assessment in the training course. Twelve residents without prior experience of microcatheter shaping and 25 neurovascular clinicians who have in vivo experience of microcatheter shaping on 3-5 occasions were selected for this training program and randomly divided into the traditional training group and the experimental training group. Four senior neurovascular clinicians assisted and guided the trainees in two groups and evaluated the time and accuracy of microcatheter shaping. RESULTS: Eighteen trainees were assigned to the traditional training group, among which 4 had prior experience in microcatheter shaping. The other 19 were assigned to the experimental training group, including 8 with prior experience. No statistical difference in the distribution of experienced students between the two groups was noted(P = 0.295). After the training session, the shaping time was found shorter in the experimental training group than that in the traditional training group (40.3.5 ± 16.2 s vs. 54.2 ± 16.4 s, P = 0.014), while the shaping score was found higher in the experimental training group than that in the traditional training group (4.4 ± 0.5 vs. 2.6 ± 1.2, P < 0.001). Specifically, for the trainees without prior experience, the experimental training group also showed less time consumption and higher score (Time: 52.7 ± 7.7 vs. 61.5 ± 9.5, P = 0.02; Score 4.1 ± 0.5 vs. 2.3 ± 1.1, P < 0.01). Meanwhile, for the trainees with prior experience, the advantage was noted in shaping score (4.7 ± 0.3 vs. 3.9 ± 0.6, P < 0.01) but not in time consumption (23.3 ± 4.4 vs. 28.5 ± 3.9, P = 0.07). CONCLUSION: This training program is quite effective at teaching junior neurovascular physicians the essential surgical abilities required for coiling cerebral aneurysms.

Sialendoscopy-assisted intraoral incision approach for the treatment of posterior Wharton's duct stones: our experience and outcomes.

INTRODUCTION: Sialoliths can be removed by sialendoscopy in some cases. But sometimes it fails if the stone is located in the proximal or hilum of Wharton's duct. AIM: To evaluate the clinical efficacy of the sialendoscopy-assisted intraoral incision approach to remove large stones located in the proximal or hilum of Wharton's duct, when sialendoscopy alone fails. MATERIAL AND METHODS: Twenty patients with large stones located in the proximal or hilum of Wharton's duct were included in our study. We used a sialendoscopy-assisted intraoral incision approach to remove large stones located in the proximal or hilum of Wharton's duct when endoscopy failed. The complications and treatment effect were observed. RESULTS: The stones were removed successfully in this way in all patients. Two cases had tongue numbness after the operation, and recovered 3 months later without additional intervention. No swelling or pain appeared during the 3-month to 1-year follow-up. Saliva could be observed from the orifice in 15 patients, with little or none in 5 patients. CONCLUSIONS: The sialendoscopy-assisted intraoral incision approach to remove large stones located in the proximal or hilum of Wharton's duct is effective and safe.

Geometries, stabilities and electronic properties of beryllium-silicon Be2Si(n) clusters.

The equilibrium geometries, growth patterns, stabilities, and electronic properties of bimetallic Be2Si(n) (n = 1-11) clusters are systematically investigated at the B3LYP/6-311G(d) level of theory. Harmonic vibrational analysis has been performed to assure that the optimized geometries are stable. The optimized results suggest that the three-dimensional structures are observed for the most stable isomers of Be2Si(n) clusters when n > 2. The calculated vertical ionization potential for the lowest-energy isomers are comparable to the experimental values of Si(n+2). According to the averaged binding energy, fragmentation energy, second-order energy difference and HOMO-LUMO gaps calculations, we identify that the Be2Si2 and Be2Si5 clusters are more stable, and Be atoms doping enhance the chemical reactivity of the Si n host. The natural population and natural electron configuration analyses indicate that the Be atoms possess positive charge at n = 1-5 but negative charge at n = 6-11. The chemical hardness of Be2Si(n) clusters show three local maxima at n = 2, 5, and 9, whereas three local minima are found for the corresponding chemical potential, meaning these clusters are more stable than their neighboring cluster sizes.