The pneumatisation of anterior clinoid process is not associated with any predictors that might be recognised preoperatively

The anterior clinoid process (ACP) is usually removed during surgeries of proximalinternal carotid artery (ICA) aneurysms. However, some ACPs presentwith air cells originating from the sphenoid or/and ethmoid sinus. In surgeriescontaining a clinoidectomy of a pneumatised process, up to 40% of patients experience cerebrospinal fluid (CSF) rhinorrhoea. The aim of this study wasto explore the potential predictors of pneumatisation of the ACP, as well asto compare the occurrence of CSF rhinorrhoea between total and partialanterior clinoidectomies. This study comprised 2 different groups, with 2 differentanalyses. Firstly, the pneumatisation of the ACP was evaluated in 496 ACPs and was based on 248 computer tomography exams (CT). The c2 testand ROC curve comparisons were utilised in conjunction, to explore possiblepredictors of air cell accumulation in the ACP. The overall pneumatisation ratewas 9.7%, unilateral and bilateral aerial ACP was found in 4.4% and 2.6% of all patients respectively, while at least one pneumatised ACP was found in 14.1% of examined patients. The route of pneumatisation was establishedin 87.5% of cases. The side of the ACP, gender, and patient age were notsignificantly associated with both pneumatisation of ACP or route of pneumatisation.Secondly, a clinical group of 23 patients after operative securingof an ICA aneurysm were retrospectively assessed with regards to the extentof anterior clinoidectomy and the occurrence of CSF rhinorrhoea. A total of23 ACPs were removed, 17 ACPs were totally resected, and 6 underwent partialresection. CSF rhinorrhoea was not noted in any patients, thus the comparison between clinical groups was not valid. Moreover, we described a novelmethod of partial removal of the lateral aspect of ACP, which was applied in6 patients treated for an ICA — ophthalmic artery junction aneurysm

In vivo biofunctional evaluation of hydrogels for disc regeneration

Purpose Regenerative strategies aim to restore the original biofunctionality of the intervertebral disc. Different biomaterials are available, which might support disc regeneration. In the present study, the prospects of success of two hydrogels functionalized with anti-angiogenic peptides and seeded with bone marrow derived mononuclear cells (BMC), respectively, were investigated in an ovine nucleotomy model. Methods In a one-step procedure iliac crest aspirates were harvested and, subsequently, separated BMC were seeded on hydrogels and implanted into the ovine disc. For the cell-seeded approach a hyaluronic acid-based hydrogel was used. The anti-angiogenic potential of newly developed VEGF-blockers was investigated on ionically crosslinked metacrylated gellan gum hydrogels. Untreated discs served as nucleotomy controls. 24 adult merino sheep were used. After 6 weeks histological, after 12 weeks histological and biomechanical analyses were conducted. Results Biomechanical tests revealed no differences between any of the implanted and nucleotomized discs. All implanted discs significantly degenerated compared to intact discs. In contrast, there was no marked difference between implanted and nucleotomized discs. In tendency, albeit not significant, degeneration score and disc height index deteriorated for all but not for the cell-seeded hydrogels from 6 to 12 weeks. Cell-seeded hydrogels slightly decelerated degeneration. Conclusions None of the hydrogel configurations was able to regenerate biofunctionality of the intervertebral disc. This might presumably be caused by hydrogel extrusion. Great importance should be given to the development of annulus sealants, which effectively exploit the potential of (cell-seeded) hydrogels for biological disc regeneration and restoration of intervertebral disc functioningThis work was supported by the EU-project Disc Regeneration (NMP3-LA-2008-213904). Technical assistance of Iris Baum and the whole animal surgery team of the Institute of Orthopaedic Research and Biomechanics, Ulm, are gratefully acknowledged. DDAHA hydrogels were kindly provided by Cristina Longinotti (DDAHA, Anika Therapeutics, Abano Therme, Italy)