Shunichi Yoneda

Management of spontaneous carotid-cavernous fistulae

Fifteen cases of spontaneous carotid-cavernous fistulae, including 4 patients with spontaneous cure and 8 treated with electrothrombosis, are reviewed. Careful angiographic observation will verify closure of the fistula. Aggravation of visual and/or ocular symptoms can also develop with spontaneous carotid-cavernous fistulae. Recurrence of symptoms and development of collaterals were noted, especially after carotid ligation or embolization of the external carotid artery. Electrothrombosis successfully closed the fistulae in 7 patients. The internal carotid artery was occluded in 1 patient who had a preoperative carotid stenosis at the cervical level. The ability to differentiate angiographically between single and multiple fistulae provides a new possibility that spontaneous carotid-cavernous fistulae can be treated with detachable balloon catheters.

A Miniature SFT Transducer for Continuous Monitoring of Intracranial Pressure

During the past 3 years, we have developed 6 models of miniature transducers for the purpose of continuous monitoring of epidural or subdural intracranial pressure (ICP). Models 1 and 2 using Pixie chips (1,2) as the sensing element, and Model 3 of miniature metal strain gauge, turned out to be impractical because of their poor temperature stability or low sensitivity. Models 4, 5, 6 transducers used the SFT (semiconductor film strain transducer) as the sensing element. Model 6 SFT has been finally designed in this series and used in clinical practice.