Comparison of the Prevalence of Ruptured and Unruptured Cerebral Aneurysms in a Poor Urban Minority Population.

BACKGROUND: Most ruptured cerebral aneurysms are small (<7 mm). Evidence suggests low rupture rates for such lesions (<1% per year). Population studies demonstrate a prevalence rate of 3.2%. This study simultaneously estimates the prevalence of aneurysms in a single geographic population while reporting the observed rate of aneurysmal subarachnoid hemorrhage (aSAH) in the same geographic region composed of a poor urban minority demographic. METHODS: This is an institutional review board-approved, Health Insurance Portability and Accountability Act of 1996-compliant retrospective study performed between 2005 and 2011 at a single center. Part 1 used the electronic medical record to identify all patients with a magnetic resonance angiography demonstrating a cerebral aneurysm. Part 2 used the electronic medical record to identify all patients from the same geographic area presenting with aSAH during the study period. RESULTS: A total of 11,160 subjects had a magnetic resonance angiography from the study area. In this group, 422 intradural cerebral aneurysms were incidentally discovered. Ninety-one percent were less than 10 mm (mean 5.49, standard deviation 4.6). Twenty-one percent were aneurysms of the anterior communicating artery complex. Fourteen percent were of posterior communicating artery origin. A total of 237 patients had aSAH. Ninety-two percent of the aneurysms were less than 10 mm (mean 6 mm, standard deviation 3.2 mm). Both groups were composed of poor urban minority patients. CONCLUSIONS: The observed annual rate of rupture of small anterior circulation aneurysms in this study was .06%-.15% per year. The extrapolated population prevalence of such aneurysms (4.0%-1.5%) may explain the observed rate of rupture of these small aneurysms in a poor urban minority population.

Flow-Diverting Stents for the Obliteration of Symptomatic, Infectious Cavernous Carotid Artery Aneurysms.

BACKGROUND: Intracavernous aneurysms constitute up to 9% of all intracranial aneurysms and 6% are infectious (IIA). First line therapy is a protracted antibiotic course, yet with failure, surgery and endovascular parent vessel sacrifice have been utilized. Reconstructive endovascular therapies have emerged for aneurysm control and may demonstrate a safer therapeutic alternative. OBJECTIVE: To present an IIA treated with a flow-diverting Pipeline stent (ev3 Neurovascular, Irvine, California). METHODS: A 41-yr-old female presented with visual loss, ophthalmoplegia, and cavernous sinus thrombosis with an associated phlegmon. Transsphenoidal evacuation was performed without complication or bleeding and she continued on medical therapy. Two weeks postoperatively, she developed a worsening right third cranial nerve palsy and MRA demonstrated a 1-cm right IIA, not evident on postoperative MRI. Three days of dual antiplatelet therapy preceded successful pipeline embolization. Angiography demonstrated aneurysm obliteration at 3 mo and her right ophthalmoplegia resolved. RESULTS: A literature review identified 6 reported cases of IIAs treated with stent embolization. Only 1 documented a flow-diverting Silk stent used in a child. All lesions were obliterated at follow-up without neurological sequelae. No complication arose with implantation in the setting of infection, and as few as 3 d of dual antiplatelet therapy was sufficient for preprocedural prophylaxis, although in Vivo antiplatelet activity may be more significant. CONCLUSION: We report the first case of an IIA treated with a flow-diverting pipeline stent. These devices preserve native vasculature and neurological function compared to surgical and endovascular vessel sacrifice strategies. They appear to be safe management options for the treatment of IIAs.

Clinical assessment of percutaneous lumbar pedicle screw placement using theO-arm multidimensional surgical imaging system.

BACKGROUND: Increasing popularity of minimally invasive surgery for lumbar fusion has led to dependence upon intraoperative fluoroscopy for pedicle screw placement, because limited muscle dissection does not expose the bony anatomy necessary for traditional, freehand techniques nor for registration steps in image-guidance techniques. This has raised concerns about cumulative radiation exposure for both surgeon and operating room staff. The recent introduction of the O-arm Multidimensional Surgical Imaging System allows for percutaneous placement of pedicle screws, but there is limited clinical experience with the technique and data examining its accuracy. OBJECTIVE: We present the first large clinical series of percutaneous screw placement using navigation of O-arm imaging and compare the results with the fluoroscopy-guided method. METHODS: A retrospective review of a 24-month period identified patients undergoing minimally invasive lumbar interbody fusion. The O-arm was introduced in the middle of this period and was used for all subsequent patients. Accuracy of screw placement was assessed by examination of axial computed tomography or O-arm scans. RESULTS: The fluoroscopy group included 141 screws in 42 patients, and the O-arm group included 205 screws in 52 patients. The perforation rate was 12.8% in the fluoroscopy group and 3% in the O-arm group (P < .001). Single-level O-arm procedures took a mean 200 (153-241) minutes, whereas fluoroscopy took 221 (178-302) minutes (P < .03). CONCLUSION: Percutaneous pedicle screw placement with the O-arm Multidimensional Intraoperative Imaging System is a safe and effective technique and provided improved overall accuracy and reduced operative time compared with conventional fluoroscopic techniques.