Cerebral venous thrombosis at high altitude: A systematic review.

BACKGROUND AND OBJECTIVE: High altitude may be a factor associated with cerebral venous thrombosis (CVT). As our knowledge of CVT at high altitude is limited, it was decided to pool such information from the available case studies to determine whether high altitude can predispose to CVT. METHODS: A systematic review of the literature was performed for cases reporting CVT at high altitude. Searches of the PubMed database (up to July 2016) were performed for publications, using 'cerebral venous thrombosis' and 'high altitude' as keywords. Cross-referencing was also done to complete the search. RESULTS: Ultimately, 13 articles were included in our systematic review. The population consisted of 17 patients, predominately male (14/17), with a mean age of 32 (range: 19-47) years. Altitude range was 3000-8200m. Nine patients stayed at high altitude for>2 weeks; the duration of high altitude stay was unknown for the remainder. A hypercoagulable state was found in nine patients: secondary polycythemia in five; protein C deficiency in one; protein S deficiency in one; and factor V Leiden mutations in two. No comorbidities were found in any of these patients. CONCLUSION: Long-term stays at high altitude in association with a hypercoagulable state - in particular, congenital or acquired thrombophilia - appears to predispose to CVT. The association of CVT with a single exposure to high altitude seems low, but the risk cannot as yet be specifically estimated.

Total endoscopic approach to the cauda in a patient with a tight filum.

In this report we describe a patient with a tight filum associated with a small concentric lipoma that was treated by cutting the filum terminale through a totally endoscopic approach. Our approach required the creation of a midline surgical corridor provided by the placement of a telescopic self-retaining retractor over the ligamentum flavum at L5-S1, under endoscopic control. The ligamentum was partially removed, the dura and the arachnoid opened and the filum terminale and the roots of the cauda exposed. After neurophysiological confirmation of the absence of neural structures the filum was coagulated and cut, the dura was closed by a continuous suture and sealed with fibrin glue. The entire surgery was performed under the illumination and magnification provided by a rigid endoscope working in an aerial environment. This case shows that the cauda can be explored and the filum terminale cut with a minimally invasive endoscopic approach that does not significantly compromise the structural integrity of the spine, requires only a short dural incision, therefore reducing the risk of postoperative cerebrospinal fluid leakage, and allows the use of multiple surgical instruments in an aerial environment.