Our data suggests that the use of VNG leads to a faster regeneration process and a better functional recovery, although the final results are comparable to those of the NNG. VNG improve the quality of the axonal regeneration (axonal diameter and Schwann cells), although the increase in the axonal number is not significant and does not improve the long-term functional outcome.

OBJECTIVE The aim of this study was to define predictive factors for rupture of middle cerebral artery (MCA) mirror bifurcation aneurysms. METHODS The authors retrospectively analyzed the data in patients with ruptured MCA bifurcation aneurysms with simultaneous presence of an unruptured MCA bifurcation mirror aneurysm treated in two neurosurgical centers. The following parameters were measured and analyzed with the statistical software R: neck, dome, and width of both MCA aneurysms-including neck/dome and width/neck ratios, shape of the aneurysms (regular vs irregular), inflow angle of both MCA aneurysms, and the diameters of the bilateral A and M segments and the frontal and temporal M trunks, as well as the bilateral diameter of the internal carotid artery (ICA). RESULTS The authors analyzed the data of 44 patients (15 male and 29 female, mean age 50.1 years). Starting from the usual significance level of 0.05, the Sidak-corrected significance level is 0.0039. The diameter of the measured vessels was statistically not significant, nor was the inflow angle. The size of the dome was highly significant (p = 0.0000069). The size of the neck (p = 0.0047940) and the width of the aneurysms (p = 0.0056902) were slightly nonsignificant at the stated significance level of 0.0039. The shape of the aneurysms was bilaterally identical in 22 cases (50%). In cases of asymmetrical presentation of the aneurysm shape, 19 (86.4%) ruptured aneurysms were irregular and 3 (13.6%) had a regular shape (p = 0.001). CONCLUSIONS In this study the authors show that the extraaneurysmal flow dynamics in mirror aneurysms are nonsignificant, and the aneurysmal geometry also does not seem to play a role as a predictor for rupture. The only predictors for rupture were size and shape of the aneurysms. It seems as though under the same conditions, one of the two aneurysms suffers changes in its wall and starts growing in a more or less stochastic manner. Newer imaging methods should enable practitioners to see which aneurysm has an unstable wall, to predict the rupture risk. At the moment one can only conclude that in cases of MCA mirror aneurysms the larger one, with or without shape irregularities, is the unstable aneurysm and that this is the one that needs to be treated.

BACKGROUND:Although numerous articles have been published not only on the classification of thoracic outlet syndrome (TOS) but also on diagnostic standards, timing, and type of surgical intervention, there still remains some controversy because of the lack of level 1 evidence. So far, attempts to generate uniform reporting standards have not yielded conclusive results.OBJECTIVE:To systematically review the body of evidence and reach a consensus among neurosurgeons experienced in TOS regarding anatomy, diagnosis, and classification.METHODS:A systematic literature search on PubMed/MEDLINE was performed on February 13, 2021, yielding 2853 results. Abstracts were screened and classified. Recommendations were developed in a meeting held online on February 10, 2021, and refined according to the Delphi consensus method.RESULTS:Six randomized controlled trials (on surgical, conservative, and injection therapies), 4 “guideline” articles (on imaging and reporting standards), 5 observational studies (on diagnostics, hierarchic designs of physiotherapy vs surgery, and quality of life outcomes), and 6 meta-analyses were identified. The European Association of Neurosurgical Societies’ section of peripheral nerve surgery established 18 statements regarding anatomy, diagnosis, and classification of TOS with agreement levels of 98.4 % (±3.0).CONCLUSION:Because of the lack of level 1 evidence, consensus statements on anatomy, diagnosis, and classification of TOS from experts of the section of peripheral nerve surgery of the European Association of Neurosurgical Societies were developed with the Delphi method. Further work on reporting standards, prospective data collections, therapy, and long-term outcome is necessary.