Pseudotumor cerebri (PTC), or idiopathic intracranial hypertension, is a syndrome associated with multiple clinical conditions. We hypothesize that most if not all etiologies result in an increase in intracranial venous pressure as a final common pathway. We studied 10 patients with PTC. Five had dural venous outflow obstruction as demonstrated by venography, and the five remaining patients had normal venous anatomy. Pressure measurements, made during venography in eight patients, all showed elevated pressures. Pressure measurements in the superior sagittal sinus ranged from 13 to 24 mm Hg (mean, 16.6 mm HG). Patients with obstruction tended to have a high pressure gradient across the stenotic segment. Five patients with normal dural venous anatomy had elevated right atrial pressures (range, 6 to 22 mm Hg; mean, 11.8 mm Hg), which were transmitted up to the intracranial venous sinuses. Endovascular techniques, including angioplasty and infusion of thrombolytic agents in some cases, improved outlet obstruction from a hemodynamic perspective but were ineffective in consistently and reliably alleviating the clinical manifestations of PTC. Patients in both groups tended to respond well to conventional CSF diversion procedures. Our study suggests that elevated intracranial venous pressure may be a universal mechanism in PTC of different etiologies. This elevated venous pressure leads to elevation in CSF and intracranial pressure by resisting CSF absorption. Although the mechanism leading to venous hypertension in the presence of outflow obstruction is obvious, the etiology of increased intracranial and central systemic venous pressure in PTC remains obscure.

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A video-assisted thoracoscopic microsurgical approach was developed in the laboratory and subsequently used clinically to resect abnormalities of the thoracic vertebrae, to decompress the thoracic spinal cord, and to reconstruct the thoracic vertebral bodies. This report describes the development of the clinical operative techniques for microsurgical thoracoscopic vertebrectomy, neural decompression, and spinal reconstruction. This minimally incisional approach was clinically used in 17 patients to treat vertebral osteomyelitis, tumors, and compression fractures. Microsurgical thoracoscopic techniques were performed using several narrow, flexible, working portals placed in small incisions in the intercostal spaces. Access to the thoracic spine was achieved through the pleural cavity after temporary deflation of one lung using a double-lumen endotracheal tube. The parietal pleura, segmental vessels, and rib heads were dissected off the surfaces of the involved vertebrae to expose the region of interest. Long narrow spine dissection tools were used to perform the spinal decommpression and reconstruction. This technique achieved the same amount of spinal dissection as that achieved with conventional open spinal procedures and used microsurgical visualization techniques. The small incisions with reduced soft tissue dissection may reduce postoperative pain, shorten the length of hospitalization, and have cosmetic and functional advantages. Thoracoscopic vertebrectomies and reconstruction of the spine were technically feasilble procedures that were performed with excellent clinical results. This minimally incisional technique provides a viable alternative to thoracotomy or to posterolateral approaches for thoracic vertebrectomy and vertebral body reconstruction.