Orthogonal polarization spectral imaging is a suitable method to study cerebral microcirculation during surgery. In patients with SAH, capillary density is significantly decreased and small arteries and arterioles of the cortical surface exhibit vasospasm that cannot be detected by angiography or transcranial Doppler sonography. These changes may contribute to the initial clinical symptoms and may have an influence on the clinical postoperative course.

One- and two-level ACDF with stand-alone empty PEEK cages achieved very high fusion rates and a low rate of follow-up operations. The rate of good clinical outcome is highly satisfactory. Younger age was the single most influential factor associated with better clinical outcome.

Summary:The contribution of leukocytes to secondary brain damage after cerebral ischemia is still under discussion. The purpose of the present study was to examine the pial microcir culation after global cerebral ischemia while focusing on leu kocyte-endothelium interactions during the early and late reperfusion period of up to 4 days. A closed cranial window technique that leaves the dura mater intact was used. Global cerebral ischemia of J 5 minutes' duration was induced in male Mongolian gerbils (n = 91). Pial microcirculation was ob served by intravital fluorescence microscopy. Leukocyte endothelium interactions (LEIs) in pial venules, vessel diam eters, capillary density, and regional microvascular blood flow measured by laser Doppler flowmetry were quantified during 3 hours of reperfusion and in intervals up to 4 days after isch emia. Within 3 hours of reperfusion, the number of leukocytes (cellsllOO ILm x minute) rolling along or adhering to the venular endothelium increased from 0.1 ± 0.2 to 28.4 ± 17.4 (P The activation of leukocytes during postischemic reperfusion is a pathophysiologic phenomenon that oc curs in a variety of peripheral organs as well as in brain tissue (del Zoppo et aI., 1991; Engler et aI., 1983; Hal lenbeck et aI., 1986; Menger et al., 1992). The attach ment of leukocytes to the venular endothelium and sub sequent emigration of the cells into the brain parenchyma may contribute to the development of secondary brain damage after the primary ischemic insult (Kochanek and Hallenbeck, 1992). This hypothesis, however, is mainly Abbreviations used: GCI, global cerebral ischemia; LEI, leukocyte endothelium interaction; rCBF, regional cerebral blood flow. 979< 0.01 vs. control) and from 0.2 ± 0.2 to 4.0 ± 3.8 (P < 0.05), respectively. There was no capillary plugging by leukocytes; capillary density remained unchanged. In the late reperfusion period, at 7 hours after ischemia, LEIs had returned to baseline values. Furthermore, from 12 hours to 4 days after ischemia, no LEIs were observed. Changes in regional microvascular blood flow did not correlate with LEIs. Global cerebral ischemia of 15 minutes' duration induces transient LEIs that reach a maxi mum within 3 hours of reperfusion and return to baseline at 7 hours after ischemia. LEIs are not related to changes in micro vascular perfusion, which suggests mainly that the expression of adhesion receptors is necessary to induce LEIs rather than rheologic factors. It seems unlikely that this short-lasting acti vation of leukocytes can play a role in the development of secondary brain damage.

The transoral route is the gold standard for odontoid resection. Results are satisfying though surgery can be challenging for patients and surgeons due to its invasiveness. A less invasive transnasal approach could provide a sufficient extent of resection with less collateral damage. The technique of transnasal endoscopic odontoid resection is demonstrated by a case series of three patients. A fully endoscopic transnasal odontoid resection was conducted by use of CT-based neuronavigation. A complete odontoid resection succeeded in all patients. Symptoms such as dysarthria, swallowing disturbance, salivary retention, myelopathic gait disturbances, neck pain, and tetraparesis improved in all patients markedly. Transnasal endoscopic odontoid resection is a feasible alternative to the transoral technique. It leaves the oropharynx intact, which could result in lower approach related complications especially in patients with bulbar symptoms.

Use of PEEK cages for interbody fusion is feasible and safe in patients suffering from a pyogenic spinal infection.

The incidence of injury to the cervical vertebral artery during surgery for stenosis of the cervical neuroforamina is very low. We present a case in which bleeding during microforaminotomy at the level C6/7 occurred. The bleeding could be controlled intraoperatively. Two days later, a life-threatening cervical hematoma required urgent bedside evacuation. A false aneurysm of the left cervical vertebral artery was successfully occluded by a modified triple stent-in-stent technique, maintaining the flow in the vessel.

We therefore conclude that CT navigated pedicle screws can be positioned safely although greater caution must be taken in patients who have previously undergone anterior surgery. Cite this article: 2017;99-B:1373-80.

Basilar perforator artery aneurysms (BAPA's) are an under-recognised cause of sub-arachnoid haemorrhage (SAH). We present our single centre experience of BAPA's and review of the literature.We performed a retrospective review of our prospectively maintained database to identify all BAPA's that presented acute SAH between February 2009 and February 2018.We identified 9 patients (male = 7), each with a single aneurysm, and average age 55 ± 9.7 years. All aneurysms were small, 2.1 ± 0.5 mm (range 1-3 mm). Three aneurysms were not detected on initial angiography. Six aneurysms were treated with flow diversion, 3 were managed conservatively. No repeat haemorrhage occurred in the flow diverted patients. One patient treated conservatively suffered a repeat haemorrhage and died (mRS 6). Follow up imaging (n = 7), at average 5.6 months (range 3-12 months), showed complete occlusion in all the flow-diverted aneurysms and no change in one conservatively managed patient. There was no evidence of perforator infarction on the follow-up post treatment imaging. Clinical follow-up data was available in 8 patients, 6 of whom (75%) had a good outcome (mRS 2).A high index of suspicion is required to diagnose BAPA. Flow diversion can be used to treat BAPA's with acceptable risk of perforator infarction and low risk of repeat haemorrhage.