Intraosseous venographic features of the skull base have been studied by the injection of a water-soluble radiopaque medium into the occipital condyle. By this method, the whole intracranial epidural venous structures of the skull bass were demonstrat...
Intraosseous venographic features of the skull base have been studied by the injection of a water-soluble radiopaque medium into the occipital condyle. By this method, the whole intracranial epidural venous structures of the skull bass were demonstrated without overlapping of the extracranial veins, except jugular veins and upper cervical vertebral venous plexi.
Since 1966, a total of 82 venographies have been performed for the diagnosis of various lesions in the skull base. This series consisted of acoustis neurinoma(3), jugular glomus. tumor(2), pituitary adenoma (6), sphenoid ridge meningioma (l), metastatic tumor (7), venous malformation (8), pachymeningitis externa(22), parasite infestation(3) trigeminal neuralgia(3), pseudotumor cerebri(16) and others(11).
Method:
Under premedication of Seconal 100 ㎎ and Demerol 50 ㎎, the patient is placed in the Bowen-Hirtz position. However, until the plain roentgenogram is taken the patient may use a pillow for a comfortable interval.
The skin of the mandibulomastoid region is perpared with iodine. A procaine wheal on superficial tissue is made 0.5 cm below the lowest attachment of the pinna.
Through this wheal an 18-guage spinal puncture needle is introduced in a slightly superior and posterior direction (superior 20˚ angle, posterior 10˚ angle) until the bony surface is touched. The needle is further introduced through the bony cortex by steady pressure and rotation. When the needle is firmly fixed the stylet is withdrawn and blood is aspirated from the needle as if in a vein. If free injection with 3~5cc of a saline is established easily by hand, the stylet should be replaced as before. The pillow is then removed and a plain X-ray film, submentovertical view, is taken.
After confirmation of an adequate placement of the needle to the occipital condyle on the roentgenogram, an injection of 30 cc of 60% angioconray is made as rapidly as possible by hand or a pressure injector. This is the only part of the examination that may cause discomfort to the patient. A film should be taken toward the end of the injection. One film is usually sufficient.
Manual jugular compression and/or Vasalva maneuvers, to increase opacification, may be used but its efficacy is not always sufficiently constant. Satisfactory jugular compression can be obtained by use of a sphygmomanometer cuff, adjusted around the neck and inflated up to about 50 mmHg.
With this technique the whole venous structure of the skull base, includding the middle meningeal and orbital sinuses, can be visualized. This method, because of the close situation of the occipital condyle, has the advantage of demonstrating the whole marginal sinus of the foramen magnum and the upper cervical vertebral venous plexi. To date no complications have been encountered. Its diagnostic significance is gratifying in detecting the extent and localization of space-occupying lesions, inflammatory processes and venous thrombsois or malformation of the skull base.