Dissecting aneurysms of the distal segment of the posterior inferior cerebellar arteries: clinical presentation and management.

BACKGROUND AND PURPOSE: Dissecting aneurysms of the distal segment of the PICA are rare. The purpose of this study was to evaluate the clinical presentations, imaging features, treatment options, and clinical outcomes of dissecting PICA aneurysms. MATERIALS AND METHODS: Six patients with dissecting aneurysms in the distal segments of PICA were found in the database of a single medical center, from November 1996 to December 2008, and retrospectively evaluated. Treatment mode and follow-up clinical outcomes were analyzed. RESULTS: Five patients with dissecting PICA aneurysms presented with acute intracranial hemorrhage and 1 patient presented with a large mass from an intramural hematoma. All 5 patients with intracranial hemorrhage were treated with endovascular occlusion of both the dissecting PICA aneurysm and the distal parent artery. The patient with the intramural hematoma underwent surgical trapping with end-to-end anastomosis. In 1 patient, the dissecting aneurysm recurred twice within a 5 year 3 month period, despite endovascular occlusion of both the aneurysm and the parent artery. The clinical outcome postprocedure was excellent in all patients, without permanent neurologic complication. CONCLUSIONS: For the endovascular treatment of dissecting aneurysms in the distal PICA segments, we recommend occlusion of both the dissecting aneurysm and the parent artery to avoid leaving the point of initial intimal tear untreated. All of our patients had excellent clinical outcomes; however, our experience with recanalization illustrates the need for close follow-up of patients.

Intraoperative computed tomography for complex craniocervical operations and spinal tumor resections.

OBJECTIVE: To improve intraoperative observation of unexposed anatomic features and to verify surgical correction, a mobile computed tomographic (CT) scanner has been introduced into the operating room. To date, intraoperative CT scanning has been used predominantly for intracranial procedures. We report on the expanded use of intraoperative CT scanning for spinal surgery, because CT scanning provides excellent observation of osseous pathological features. We report on our first 17 cases, which involved complex craniocervical operations and spinal tumor resections. METHODS: The Tomoscan M CT scanner (Philips Medical Systems, Eindhoven, The Netherlands) is mobile and consists of a translatable gantry, a translatable table, and an operator's workstation. In the operating room, the patient is placed on the CT table and prepared in the usual manner. The aperture of the gantry is covered with sterile plastic drapes. The gantry is docked to the table for intraoperative CT scanning as needed for navigation and verification during surgery. Each series of scans requires approximately 15 to 20 minutes. RESULTS: Our initial experience with neurosurgical spinal cases demonstrated that the use of intraoperative CT scanning changed the course of surgery in 6 of 17 cases. CT scanning was beneficial in facilitating adequate ventral clival and craniocervical decompressions, promoting more complete tumor resections, and verifying correct graft and instrument placement before surgical closing. Other settings in which we have found the mobile CT scanner useful include the neurointerventional suite and the intensive care unit; it is also useful for radiotherapy planning. CONCLUSION: On the basis of findings for our first 17 spinal surgery cases, we conclude that intraoperative CT scanning of the spine is both feasible and beneficial for select complex spinal procedures from the craniocervical junction to the sacrum.

Early lethality, functional NF-kappaB activation, and increased sensitivity to TNF-induced cell death in TRAF2-deficient mice.

TRAF2 is an intracellular signal-transducing protein recruited to the TNFR1 and TNFR2 receptors following TNF stimulation. To investigate the physiological role of TRAF2, we generated TRAF2-deficient mice. traf2-/- mice appeared normal at birth but became progressively runted and died prematurely. Atrophy of the thymus and spleen and depletion of B cell precursors also were observed. Thymocytes and other hematopoietic progenitors were highly sensitive to TNF-induced cell death and serum TNF levels were elevated in these TRAF2-deficient animals. Examination of traf2-/- cells revealed a severe reduction in TNF-mediated JNK/SAPK activation but a mild effect on NF-kappaB activation. These results suggest that TRAF2-independent pathways of NF-kappaB activation exist and that TRAF2 is required for an NF-kappaB-independent signal that protects against TNF-induced apoptosis.