Stability-Sparing Endoscopic Endonasal Odontoidectomy in a Malformative Craniovertebral Junction: Case Report and Biomechanical Considerations.

BACKGROUND: The craniovertebral junction (CVJ) is often involved in a wide range of congenital, developmental and acquired pathologies that can create bony and ligamentous instability or cause direct compression on the medulla and cervical spine cord, resulting in significant impairment. Atlas assimilation is the most common malformation in the CVJ and can be frequently associated with basilar invagination (BI) and Chiari malformation (CM) type I. Posterior atlas assimilation more frequently leads to BI type II with a mass effect on neural structures but usually no signs of biomechanical instability. Operative approaches to the CVJ have undergone a remarkable evolution and can be divided into ventral, lateral and dorsal ones. In this kind of surgery, it is vital to detect and eventually treat any CVJ instability. CASE DESCRIPTION: We present a case of CVJ malformation comprising assimilation of the posterior arch of the atlas, BI type II and CM, treated by endoscopic endonasal odontoidectomy and partial clivus removal to spare CVJ stability. CONCLUSION: Neurological and biomechanical analysis of all CVJ malformations permits stratification and selection of those cases that can be managed by simple, direct, minimally invasive decompression with no need for surgical fusion.

Transcranial color-coded duplex sonography for evaluation of midline-shift after chronic-subdural hematoma evacuation (TEMASE): A prospective study.

OBJECTIVE: The incidence of chronic Subdural hematoma (cSDH) is increasing and its rate of recurrence varies from 5 to 33%. A postoperative brain midline-shift (MLS) on computed tomography (CT) equal or larger than 5mm is a risk factor for recurrence. Transcranial color-coded duplex sonography (TCCDS) is a noninvasive bedside reproducible technique useful to detect MLS. The aim of our study was to compare in patients affected by cSDH, the values of MLS obtained pre- and post-operatively by TCCDS and brain CT. PATIENTS AND METHODS: 32 patients affected by cSDH entered the study between July 2016 and January 2017. MLS values obtained by TCCDS and brain CT were compared using Bland-Altman plot and linear regression analysis. Using the same techniques we also explored if the agreement between the two imaging modes was comparable in pre- and post-operative data pairs. RESULTS: 64 data pairs of MLS values obtained by TCCDS and CT were analysed. Bland-Altman diagrams did not show any systematic bias of the data and linear regression indicated a significant correlation between the two measures both before and after hematoma evacuation. CONCLUSION: In patients affected by cSDH, MLS values obtained before and after surgery by TCCDS are comparable to those obtained by CT; TCCDS might be considered an alternative to CT scan in the management of patients after cSDH evacuation. We suggest that close clinical bedside examination and TCCDS might be appropriate for the post-operative management of cSDH, reserving CT scan only to patients with overt clinical deterioration and/or increasing MLS.