http://www.sciencedirect.com/science/ar ... 199700476X
Volume 51, Issue 5, May 1999, Pages 500-505
Compression of the internal jugular vein by the transverse process of the atlas as the cause of cerebellar hemorrhage after supratentorial craniotomy
Department of Department of Microsurgical Anatomy, University of Florida, Gainesville, Florida, USA
Department of Neurological Surgery, University of Florida, Gainesville, Florida, USA
The cerebellar hemorrhage reported in numerous cases after supratentorial craniotomy has uniformly exhibited the characteristics of hemorrhage associated with venous infarction rather than arterial bleeding. The cause has remained obscure, although previous reports suggested that the cause may be obstruction of flow in the internal jugular vein immediately below the base of the skull.
The microsurgical anatomy of 36 internal jugular veins in the upper cervical region were defined in adult cadaveric specimens using 3–40× magnification with special attention to the relationship of the vein to the atlas.
In every specimen, the posterior wall of the internal jugular vein rested against the transverse process of the atlas as the vein descended immediately below the jugular foramen. In 14 of 36 specimens, the transverse process indented the posterior wall of the vein, causing the vein to be slightly or moderately angulated as it descended across the anterior surface of the transverse process. Three veins were severely kinked as they descended across the transverse process of the atlas.
Obstruction of flow in the internal jugular vein at the site where the vein descends across the transverse process of the atlas is a likely cause of the venous hypertension that has resulted in the cerebellar hemorrhage reported in numerous cases after supratentorial craniotomy. An examination of the biomechanics of the region confirms that turning the head to the side opposite a supratentorial craniotomy and extending the neck, common practices with unilateral supratentorial craniotomy, further aggravates the angulation and obstruction of the internal jugular vein at the transverse process of C1 on the side ipsilateral to the craniotomy.
This research is in patients who hemorrhaged after brain surgery. If venous hypertension as a result of jugular obstruction would contribute to such an event, in the unlikely event that we need such brain surgery, then it is good if we've had our jugular obstructions fixed. Three patients had severely kinked internal jugular veins at the area of the atlas. In CCSVI this might be considered a physiological obstruction. In a living patient, an IR might look at the upper narrowing with IVUS from the inside of the vein, check to see if the vein expands (which it should, because even with the atlas pressing in on one side, there should be nothing compressing from the other side), then treat any jugular valve obstructions which are so common in pwMS, and then look at the upper narrowing again. Increased flow due to the valve obstruction having been cleared may have been enough to clear the upper narrowing as well. Even if it seemed to be due to an atlas compressing the vein, if there was nothing compressing on the other side, the vein would still be able to expand to accomodate an increase in flow. If not, treatment at the upper narrowing might be considered, or not, depending on the IR's philosphy. A stent inside the vein might be the answer. I don't know that an atlas can physically be moved away from compressing a jugular. These are large structures.
These possibilities are worth talking about, in the context of CCSVI as defined by Dr. Zamboni. Upper cervical care might be complementary treatment, but it is not the same as endovascular treatment. This forum is under the category of 'treatments,' meaning the CCSVI treatment of venoplasty, although we certainly do discuss theory and meds and everything, which is good, as long as the discussion does not muddy the definitions, because there might still be people looking for information on CCSVI who end up here, at the birthplace of CCSVI in social media thanks to cheerleader and dignan and mrhodes and everyone who was around in 2008 and 2009.