Pipeline-assisted coiling versus pipeline in flow diversion treatment of intracranial aneurysms.

BACKGROUND AND PURPOSE: Flow-diversion therapy (FDT) for large and complex intracranial aneurysms is effective and considered superior to primary coil embolization. Data evaluating common treatment with both FDT and coiling continues to emerge, but information on outcomes remains scarce. This study aims to examine further the efficiency and outcomes correlated with joint FDT using pipeline embolization device (PED) and coiling compared to PED-alone in treating intracranial aneurysms. MATERIALS AND METHODS: Comparative review and analysis of aneurysm treatment with PED in 416 subjects were conducted. Joint modality, PED, and coiling were compared to PED-alone for aneurysm occlusion, recurrence, retreatment, thromboembolic or hemorrhagic events, and functional outcome using the modified Rankin Scale. Data on patient demographics, aneurysm characteristics, clinical and angiographic follow up, were also collected. Both univariate analysis and multivariate logistic regression modeling using mixed-effects were performed. RESULTS: Total of 437 aneurysms were treated using PED of which 74 were managed with both PED and coiling. Average patient-age was 56 years, the majority were men (85%), an average aneurysm size was 9 mm, and the majority were saccular aneurysms (84%). Larger aneurysm size was associated with a poor outcome in patients with unruptured aneurysms (OR = 1.06). Adjusted regression analyses revealed no differences between treatment groups in thromboembolic or hemorrhagic events, aneurysm occlusion rate, residual flow on follow up angiography, or functional outcome. CONCLUSIONS: Treatment of intracranial aneurysms with joint PED and coiling was safe with no increase in complications when compared to PED alone. Aneurysm occlusion rates and functional outcome with PED and coiling stays comparable to treatment with PED-alone.

Pipeline Embolization Device in the Treatment of Recurrent Previously Stented Cerebral Aneurysms.

BACKGROUND AND PURPOSE: The use of the Pipeline Embolization Device in the management of recurrent previously stented cerebral aneurysms is controversial. The aim of this study was to evaluate the efficacy and safety of the Pipeline Embolization Device in the treatment of recurrent, previously stented aneurysms. MATERIALS AND METHODS: Twenty-one patients with previously stented recurrent aneurysms who later underwent Pipeline Embolization Device placement (group 1) were retrospectively identified and compared with 63 patients who had treatment with the Pipeline Embolization Device with no prior stent placement (group 2). Occlusion at the latest follow-up angiogram, recurrence and retreatment rates, clinical outcome, complications, and morbidity and mortality observed after treatment with the Pipeline Embolization Device were analyzed. RESULTS: Patient characteristics were similar between the 2 groups. The mean time from stent placement to recurrence was 25 months. Pipeline Embolization Device treatment resulted in complete aneurysm occlusion in 55.6% of patients in group 1 versus 80.4% of patients in group 2 (P = .036). The retreatment rate in group 1 was 11.1% versus 7.1% in group 2 (P = .62). The rate of good clinical outcome at the latest follow-up in group 1 was 81% versus 93.2% in group 2 (P = .1). Complications were observed in 14.3% of patients in group 1 and 9.5% of patients in group 2 (P = .684). CONCLUSIONS: The use of the Pipeline Embolization Device in the management of previously stented aneurysms is less effective than the use of this device in nonstented aneurysms. Prior stent placement can worsen the safety and efficacy profile of this device.

Spontaneous delayed migration/shortening of the pipeline embolization device: report of 5 cases.

Five patients were found to have spontaneous delayed migration/shortening of their Pipeline Embolization Devices on follow-up angiography. The device migrated proximally in 4 patients and distally in 1 patient. One patient had a subarachnoid hemorrhage and died as a result of migration of the Pipeline Embolization Device, and another patient presented with complete MCA occlusion and was left severely disabled. Mismatch in arterial diameter between inflow and outflow vessels was a constant finding. Migration of the Pipeline Embolization Device was managed conservatively, with additional placement of the device, or with parent vessel occlusion. Obtaining complete expansion of the embolization device by using a longer device, increasing vessel coverage, using adjunctive aneurysm coiling, and avoiding dragging and stretching of the device are important preventive measures. Neurointerventionalists should be aware of this potentially fatal complication and take all necessary preventive measures.

Stent-assisted coiling versus balloon remodeling of wide-neck aneurysms: comparison of angiographic outcomes.

BACKGROUND AND PURPOSE: Stent-assisted coiling and balloon-assisted coiling are 2 well-established techniques for treatment of wide-neck intracranial aneurysms. A direct comparative analysis of angiographic outcomes with the 2 techniques has not been available. We compare the angiographic outcomes of wide-neck aneurysms treated with stent-assisted coiling versus balloon-assisted coiling. MATERIALS AND METHODS: A retrospective review was conducted on 101 consecutive patients treated at our institution, 69 with stent-assisted coiling and 32 with balloon-assisted coiling. Two multivariate logistic regression analyses were performed to determine predictors of aneurysm obliteration and predictors of progressive aneurysm thrombosis at follow-up. RESULTS: The 2 groups were comparable with respect to all baseline characteristics with the exception of a higher proportion of ruptured aneurysms in the balloon-assisted coiling group (65.6%) than in the stent-assisted coiling group (11.5%, P < .001). Procedural complications did not differ between the stent-assisted coiling group (6%) and the balloon-assisted coiling group (9%, P = .5). The rates of complete aneurysm occlusion (Raymond score 1) at the most recent follow-up were significantly higher for the stent-assisted coiling group (75.4%) compared with the balloon-assisted coiling group (50%, P = .01). Progressive occlusion of incompletely coiled aneurysms was noted in 76.6% of aneurysms in the stent-assisted coiling group versus 42.8% in the balloon-assisted coiling group (P = .02). Retreatment rates were significantly lower with stent-assisted coiling (4.3%) versus balloon-assisted coiling (15.6%, P = .05). In multivariate analysis, stented aneurysms independently predicted both complete aneurysm obliteration and progression of occlusion. CONCLUSIONS: Stent-assisted coiling may yield lower rates of retreatment and higher rates of aneurysm obliteration and progression of occlusion at follow-up than balloon-assisted coiling with a similar morbidity rate.

Intracranial vertebral artery dissections: evolving perspectives.

Intracranial vertebral artery dissection (VAD) represents the underlying etiology in a significant percentage of posterior circulation ischemic strokes and subarachnoid hemorrhages. These lesions are particularly challenging in their diagnosis, management, and in the prediction of long-term outcome. Advances in the understanding of underlying processes leading to dissection, as well as the evolution of modern imaging techniques are discussed. The data pertaining to medical management of intracranial VADs, with emphasis on anticoagulants and antiplatelet agents, is reviewed. Surgical intervention is discussed, including, the selection of operative candidates, open and endovascular procedures, and potential complications. The evolution of endovascular technology and techniques is highlighted.

Validation of image analysis for enzyme histochemical and immunocytochemical staining.

Immunocytochemical and enzyme histochemical analyses of cells and tissues are used to detect changes in the extent of injury and the expression of various molecules. Image analysis quantitation offers an easier, more efficient technique to evaluate these changes. We studied the application of image analysis for evaluating enzyme histochemistry and immunocytochemistry of cells and tissues as a way to assess stroke. Using brain sections, we compared investigator and computer-generated image analysis of 2,3,5-triphenyltetrazolium chloride stained cerebral infarcts in rats subjected to 2 h middle cerebral artery occlusion and 22 h re-perfusion. Both methods documented the infarct volumes with a comparison of means of less then 5%. This suggests no difference between computer- and hand-calculated values. Computer-generated analysis was easier and faster to use. Using endothelial cell monolayers, immunocytochemical staining of a time course of heat shock protein expression was compared to a grading system using fast red chromagen counterstained with hematoxylin. Results demonstrated greater ease and efficiency with computer-generated image analysis compared to other subjective systems of analysis. Image analysis is more useful for detecting small differences in staining, especially when using 3,3-diaminobenzidine as a chromagen. Investigator bias is also reduced using this system. Our comparisons validate the use of this versatile technology to assess more easily both cell and tissues in stroke research.

Prevention of carotid angioplasty-induced bradycardia and hypotension with temporary venous pacemakers.

OBJECTIVE: Carotid angioplasty with stent placement is becoming an established treatment modality for patients with high-risk carotid stenosis. Unlike carotid endarterectomy, angioplasty causes direct mechanical dilation of the stenotic carotid artery and bulb. Stimulation of the sinus baroreceptors induces a reflexive response that consists of increased parasympathetic discharge and inhibition of sympathetic tone, which results in bradycardia and subsequent cardiogenic hypotension. METHODS: At a single institution, the experience with 43 patients treated from November 1994 to January 2000 with 47 angioplasty and stent procedures for occlusive carotid artery disease was retrospectively reviewed. Prophylactic temporary venous pacemakers were used to prevent hypotension from possible angioplasty-induced bradycardia. Pacemakers were set to capture a heart rate decrease below 60 beats per minute. Variables analyzed included demographics, etiology of disease, side of the lesion, the presence of symptoms, history of coronary artery disease, percent stenosis, type of stent used, number of dilations, pressure of dilation, and angioplasty balloon diameter. RESULTS: Ten patients were excluded because pacemakers were not used during their angioplasty procedures, and these included three emergencies and a lesion that was unrelated anatomically to the carotid sinus (petrous carotid). The remaining 37 procedures were performed in 33 patients with a mean age of 67 years, and consisted of 17 men, 16 women, 20 right and 17 left-sided lesions. The pacemakers maintained a cardiac rhythm in 23 (62%) of the 37 procedures and in no case did the pacemaker fail to respond when activated. Recurrent (56%; 10 of 18), radiation-induced (78%; 7 of 9), and medically refractory carotid stenosis (67%; 6 of 9) required intraprocedural pacing. Two patients with recurrent stenosis became hypotensive despite the aid of the pacing device but were not symptomatic. Seventy-nine percent (15 of 19) of symptomatic lesions and 57% (8 of 14) of nonsymptomatic lesions required pacing, which was statistically significant (P = 0.049). No patient experienced an operative morbidity or mortality as a consequence of the temporary pacing devices. CONCLUSION: Angioplasty-induced bradycardia is a common condition, and it is more prevalent in radiation-induced stenosis and with symptomatic lesions. Temporary venous demand pacing is a safe procedure and may prevent life-threatening, baroreceptor-induced hypotension.

Assessment of acutely unsuccessful attempts at detachable coiling in intracranial aneurysms.

OBJECTIVE: Guglielmi detachable coiling (GDC) has quickly become the most common endovascular method for the treatment of intracranial aneurysms. Although several published case series describe various authors' successful experiences or complications, few have elaborated on failed attempts. We examined our experience with GDC, and we analyzed all failed attempts at coiling. METHODS: Patients who underwent endovascular procedures from September 1995 through July 1999 were identified using endovascular case logs and billing records. Patient charts were then reviewed retrospectively for failed attempts at GDC. A treatment failure was defined as an inability to place coils into an aneurysm, a GDC procedure-related complication resulting in death, or an acute rehemorrhage from a coiled aneurysm that indicated a failure of coils to prevent rerupture. Thromboembolic events and other nonfatal sources of morbidity that did not preclude coiling of the aneurysm were analyzed only to the extent that they prevented successful coiling of the aneurysm. RESULTS: From September 1995 to June 1999, 241 patients underwent GDC embolizations or attempts. In these patients, 35 procedures were unsuccessful, including 7 deaths from intraoperative or postoperative aneurysmal rerupture. Sixteen aneurysms could not be microcatheterized, nine of which were anterior communicating artery aneurysms. Coils from 13 wide-necked aneurysms (average fundus-to-neck ratio, <2) prolapsed into the parent vessel. Three procedures were abandoned when the aneurysms were found to have normal branches filling from the dome, and three additional procedures were abandoned for technical reasons. Five deaths resulted from intraoperative aneurysm rupture, and two patients died postoperatively from rerupture. CONCLUSION: The number of successful coiling procedures has increased with experience and improved technology. The procedure still involves risks, however, primarily for patients with subarachnoid hemorrhage.

A review of size and location of ruptured intracranial aneurysms.

OBJECTIVE: To review our experience and examine the size at which aneurysms ruptured in our patient population. METHODS: Patient charts and angiograms for all patients admitted with a diagnosis of subarachnoid hemorrhage to the Thomas Jefferson/Wills Eye Hospital between April 1996 and March 2000 were reviewed. RESULTS: Of the 362 cases reviewed, definite measurements of the ruptured aneurysm were obtained in 245. The data clearly showed that most ruptured aneurysms presenting to our institution were less than 10 mm in diameter. We found that, regardless of location on the circle of Willis, 85.6% of all aneurysms presenting with rupture were less than 10 mm. Review by location shows that aneurysms of the anterior communicating artery most often presented with rupture at sizes less than 10 mm (94.4%). A large number of ruptured posterior communicating artery aneurysms also presented at sizes less than 10 mm (87.5%). This trend continued for all aneurysm sites in our review. The incidence of subarachnoid hemorrhage in Western countries is estimated at 10 per 100,000 people per year. Recent reports have indicated that aneurysms less than 10 mm in size are unlikely to rupture. CONCLUSION: We argue that the risk of small aneurysms rupturing is not insignificant, especially those of the anterior communicating artery. Our findings indicate that surgery on unruptured aneurysms should not be predicated on aneurysm size alone.

Diagnostic imaging for stroke.

With the advent of therapy for acute stroke via in intraarterial or intravenous pathway, early diagnosis with physician education is extremely important. A common theme in all studies is the continued stress on patient and physician education, rapid triage and diagnosis with the use of CT scanning, xenon blood flow or diffusion MRI, cerebral protection, and revascularization with either carotid surgery or percutaneous angioplasty for an offending lesion, if such is identified. Although the current studies are cautiously optimistic, prospective randomized trials are needed for the evaluation of intraarterial thrombolytics as well as percutaneous transluminal angioplasty. It is important that the neurosurgical community be identified as physicians who can diagnose and treat the patient with an acute stroke.

Temporal changes in sensitivity of rats to cerebral ischemic insult.

OBJECT: Experimental rat models are often used to study cerebral ischemia, yet rats are nocturnal animals that have activity cycles that are the opposite of those of humans. In the following study the authors examined the circadian rhythm of sensitivity to an ischemic insult in rats by using an intraluminal thread technique to produce reversible middle cerebral artery occlusion. METHODS: Ischemia (2 hours of blockage followed by 22 hours of reperfusion) was induced in rats according to the 24-hour clock at either 100, 400, 700, 1,000, 1,300, 1,600, 1,900, or 2,200 hours (11-14 rats per time period). The rat brains were removed, coronally sectioned, stained with 2,3,5-triphenyltetrazolium chloride and analyzed using commercially available software. Analysis of variance and cosinor-rhythmometry statistical tests were used for analysis of data. The time of day when the ischemic infarct was induced had a significant (p = 0.011) influence on the volume of the lesion. The volume of total brain infarct produced at 400 hours (7.65 +/- 1.31%) was more than three times greater than the volume produced at 1600 hours (2.1 +/- 0.34%). Cosinor-rhythm analysis indicated a peak occurrence of infarct volume at 6:02 (95% confidence interval 5:49-6:16). The size of the infarct correlated with core body temperature rhythms, which varied by 1.3 +/- 0.62 degrees C (mean +/- standard deviation). CONCLUSIONS: Circadian rhythms, as well as the reversed natural body rhythms of the rat compared with humans, should be considered when extrapolating data to human or other animal studies. Temporal rhythms may also provide information concerning the cascading disease processes associated with cerebral ischemia.

Angioplasty and stenting for carotid atherosclerotic disease.

Based on current available data, carotid endarterectomy remains the procedure of choice for stroke risk reduction at the cervical carotid bifurcation, provided that certain inclusion and exclusion criteria are met. There exists, however, a group of patients who do not fulfill criteria related to the various studies for carotid occlusive disease, and these patients may be candidates for other procedures to achieve stroke risk reduction such as carotid angioplasty and stenting. This article provides a brief history of angioplasty percutaneous revascularization and discusses patient selection, methodology, and clinical results of carotid angioplasty and stenting.

Combining stereotactic angiography and 3D time-of-flight magnetic resonance angiography in treatment planning for arteriovenous malformation radiosurgery.

PURPOSE: This study was initiated to evaluate the advantages of using three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA), as an adjuvant to conventional stereotactic angiography, in obtaining three-dimensional information about an arteriovenous malformation (AVM) nidus and in optimizing radiosurgical treatment plans. METHODS AND MATERIALS: Following angiography, contrast-enhanced MRI and MRA studies were obtained in 22 consecutive patients undergoing Gamma Knife radiosurgery for AVM. A treatment plan was designed, based on the angiograms and modified as necessary, using the information provided by MRA. The quantitative analysis involved calculation of the ratio of the treated volume to the MRA nidus volume (the tissue volume ratio [TVR]) for the initial and final treatment plans. RESULTS: In 12 cases (55%), the initial treatment plans were modified after including the MRA information in the treatment planning process. The mean TVR for the angiogram-based plans was 1.63 (range 1.17-2.17). The mean coverage of the MRA nidus by the angiogram-based plans was 93% (range 73-99%). The mean MRA nidus volume was 2.4 cc (range 0. 6-5.3 cc). The MRA-based modifications resulted in increased conformity with the mean TVR of 1.46 (range 1.20-1.74). These modifications were caused by MRA revealing irregular nidi and/or vascular components superimposed on the angiographic projections of the nidi. In a number of cases, the information from MRA was essential in defining the nidus when the projections of the angiographic outlines showed different superior and/or inferior extent of the nidus. In two cases, MRA revealed irregular nidi, correlating well with the angiograms and showed that the angiographically acceptable plans undertreated 27% of the MRA nidus in one case and 18% of the nidus in the other case. In the remaining 10 cases (45%), both MRI and MRA failed to detect the nidus due to surgical clip artifacts and the presence of embolizing glue. CONCLUSIONS: The 3D TOF MRA provided information on irregular AVM shape, which was not visualized by angiography alone, and it was superior to MRI for defining the AVM nidus. However, when imaging artifacts obscured the AVM nidus on MRI and MRA, angiography permitted detection of AVM. Utilizing MRA as a complementary imaging modality to angiography increased accuracy of the AVM radiosurgery and allowed for optimal dose planning.

The interventional neuroradiology suite as an operating room.

The evolution of new neurointerventional techniques, along with improved imaging and catheter developments, has changed the interventional suite into a subspecialized operating room. This article discusses this operating room as a combination of neuroanesthesia, neuromonitoring, nursing, and technician support coordinated by the neruointerventionalist. The coordination of elective and emergent intervention is also discussed, from conception to completion of the plan, including arteriovenous emoblization, endovascular aneurysm obliteration, intra-arterial thrombolysis, extracranial and intracranial carotid angioplasty, and stenting. Specific examples are illustrated, including pharmacologic intervention complementing these techniques.

Endosaccular thrombosis of cerebral aneurysms: strategy, indications, and technique.

Endovascular occlusion of a cerebral aneurysm refers to the induction of thrombosis within the aneurysm by any of several methods, all of which make use of devices delivered through the bloodstream of the parent vessel. The type of endovascular treatment most commonly used today for aneurysm treatment is the detachable platinum microcoil designed by Guglielmi, known as the GDC. The GDC has been used more frequently and successfully over the last decade as a treatment alternative to microneurosurgical clip ligation. A continual and rapid technological evolution and increasing clinical experience of neurosurgeons and neuroradiologists using this technology have been important contributors to its success. Endovascular coil embolization may hold advantages over microneurosurgical clip ligation under selected clinical circumstances. It is also necessary to acknowledge and outline the disadvantages of this form of treatment in an unbiased manner.

Safety of intrathecal sodium nitroprusside for the treatment and prevention of refractory cerebral vasospasm and ischemia in humans.

BACKGROUND AND PURPOSE: The delayed type of cerebral vasoconstriction known as cerebral vasospasm (DCV) remains an important cause of permanent neurological injury and death following aneurysmal subarachnoid hemorrhage despite best current medical therapy. The mechanism of DCV remains unknown. A new treatment for refractory DCV using intrathecally delivered sodium nitroprusside and results in 21 patients is reported. METHODS: Candidates for treatment were patients with secured cerebral aneurysms presenting with clinical or radiographic SAH of grade 3 or higher. Patients with and without established DCV were treated. In 57% (12/21 patients) the diagnosis of severe DCV refractory to conventional treatment (HHH therapy and nimodipine) was established before treatment. Ten patients received ITSNP prophylactically. All patients with established DCV were in grave neurological condition before treatment. Procedures for vasospasm reversal were performed under simultaneous angiographic control with extensive hemodynamic and neurophysiologic monitoring. ITSNP was delivered by intraventricular or subdural catheter or by direct intraoperative suffusion. End points of intervention for established DCV were (1) durable angiographic reversal of vasoconstriction, (2) failure to effect reversal within 30 minutes, and (3) adverse effect. End points for DCV prevention were (1) post-SAH day 10 without evidence of vasoconstriction and (2) adverse effect. Cerebral angioplasty was used concomitantly in 9 treatments. The total number of treatments recorded was 171. RESULTS: The overall neurological outcome was good or excellent in 76% of patients (16/21) overall and in 88.9% of patients (16/18) having at least a 1-month follow-up. Of the 5 patients with less-than-good outcome, 4 had presented initially with severe neurological injury (clinical SAH grade 4). Angiography demonstrated reversal or amelioration of vasoconstriction in 83% (5/6 cases) of established DCV treated by ITSNP alone. Among patients treated prophylactically, none developed clinical DCV. CONCLUSIONS: These results suggest that ITSNP is a safe and potentially effective treatment for established DCV and cerebral ischemia refractory to conventional treatment. The preliminary results of prophylactic treatment are also favorable with regard to safety.

Therapeutic modalities for the management of cerebral vasospasm: timing of endovascular options.

OBJECTIVES: To determine if a window of time could be defined during which angioplasty would be most effective in reversing neurological decline and ultimately improving outcome. METHODS: Of a group of 466 patients, 93 underwent endovascular management of clinical vasospasm that was medically refractory. Eighty-four of the 93 patients were available for follow-up for at least 6 months. All patients underwent mechanical angioplasty using compliant microballoon systems and, if distal spasm was present, the administration of papaverine. RESULTS: Fifty-one patients underwent endovascular management within a 2-hour window, and 33 patients underwent treatment more than 2 hours after the development of their symptoms. Compared with the group treated more than 2 hours after neurological decline (P < 0.01; chi2 = 8.02), the group that underwent endovascular management within a 2-hour window after the development of symptoms demonstrated sustained clinical improvement. CONCLUSION: When a patient develops symptomatic vasospasm and is unresponsive to traditional measures of critical care management, angioplasty may be effective in improving the patient's neurological status if this procedure is performed as early as possible. The results indicate that a 2-hour window may exist for restoration of blood flow to ultimately improve the patient's outcome.

Reversal of severe cerebral vasospasm in three patients after aneurysmal subarachnoid hemorrhage: initial observations regarding the use of intraventricular sodium nitroprusside in humans.

OBJECTIVE AND IMPORTANCE: The chronic delayed type of cerebral vasoconstriction that occurs after aneurysmal subarachnoid hemorrhage (SAH) is now the most important cause of mortality and neurological morbidity for patients who initially survive the rupture of cerebral aneurysms. Although intravascular volume expansion and cardiac performance enhancement have had a profound impact on the treatment of the chronic delayed type of cerebral vasoconstriction, this form of treatment is not tolerated by all patients and is unhelpful in some. A more specific and more reliable treatment for this condition has not been previously reported. Previous work in an animal model has demonstrated the efficacy of nitric oxide-donating compounds in reversing severe cerebral vasoconstriction when delivered to the adventitial side of the blood vessel. A clinical study was initiated after receiving approval from the United States Food and Drug Administration and the institutional review board. CLINICAL PRESENTATION: Three cases of prompt and substantial reversal of medically refractory vasospasm occurring after aneurysmal SAH in humans using an intrathecally administered nitric oxide donor and clinical, angiographic, and ultrasonographic documentation are presented. All patients developed severe vasospasm refractory to medical treatment 5 to 12 days after sustaining aneurysmal SAH. All patients manifested stupor of new onset (Glasgow Coma Scale score of 7) and new focal neurological deficit (hemiplegia). The condition was angiographically demonstrated in all cases. INTERVENTION: The patients were treated with intrathecally administered sodium nitroprusside, which caused the reversal of vasospasm, which was documented by angiography and transcranial Doppler ultrasonography up to 54 hours later and also by dramatic clinical improvement. Complications related to intracranial pressure elevation, changes in vital signs, and hemodynamic parameters were not observed during or after the procedures. Radiographic evidence of the reversal of vasospasm and brain ischemia was obtained. The clinical outcomes of the treated patients were excellent. All patients presented with hemiplegia and stupor that resolved or markedly improved (within several days, two patients; within 12 hours, one patient). All three patients were discharged and were living at home at the time of manuscript submission. CONCLUSION: These preliminary observations suggest that sodium nitroprusside delivered by an intrathecal route of administration may be a useful treatment for severe vasospasm complicating SAH in humans.

Frequency of cerebral vasospasm in patients treated with endovascular occlusion of intracranial aneurysms.

UNLABELLED: The purpose of this study was to retrospectively compare a group of 19 patients treated with craniotomy and aneurysmal clipping with a group of 18 patients who were treated via endovascular occlusion with Guglielmi detachable coils in regard to frequency and severity of cerebral vasospasm. METHODS: All patients were treated within 48 hours of ictus. In the endovascular group, nine patients had Hunt and Hess grade I subarachnoid hemorrhage, five patients had grade II aneurysms, and four patients had grade III. According to the Fisher classification, one aneurysm was grade I, nine were grade II, and eight were grade III. Twelve of the aneurysms were on the anterior circulation and seven were on the posterior circulation. In the surgical group, 10 patients had Hunt and Hess grade I hemorrhage, seven had grade II aneurysms, and two had grade III. Nine of these were Fisher grade II and 10 were grade III. Eighteen aneurysms were on the anterior circulation and one was on the posterior circulation. Endovascularly treated patients were medically treated identically to those in the surgical group, with prophylactic volume expansion and hemodilution immediately after endovascular occlusion, except that they also received 48 hours of full heparinization followed by 24 hours of dextran infusion after endovascular occlusion. RESULTS: All four patients in the endovascular group in whom delayed neurologic deficits developed as a result of vasospasm responded to elevation of blood pressure and did not require either mechanical or chemical angioplasty to reverse their symptomatology. In the surgical group, 14 of 19 developed clinical vasospasm, with elevation of their transcranial Doppler velocities, and required maximum triple-H (hypertensive, hypervolemic, hemodilutional) therapy. Three of these patients required mechanical and pharmacologic angioplasty. No surgical complications were incurred as a direct result of the craniotomy. One patient in the endovascular group developed a femoral pseudoaneurysm as a complication of the procedure and postocclusion anticoagulation. No thromboembolic events were noted in this group. CONCLUSION: In patients with similar Hunt and Hess grades and Fisher grades, preliminary data suggest that the frequency and severity of cerebral vasospasm may be reduced in those treated by endovascular occlusion of their aneurysm as compared with those treated by direct surgical clipping.

Complement depletion improves neurological function in cerebral ischemia.

The contribution of the complement system to the exacerbation of cerebral ischemia/reperfusion injury was studied by comparing a group of rats with normal complement levels to another group that was complement depleted by cobra venom factor (CVF). The magnitude of reactive hyperemia was significantly greater in the complement depleted animals. There was also better preservation of somatosensory evoked potentials (SSEPs) in the complement depleted animals. These differences were not associated with changes in leukocyte infiltration as evidenced by myeloperoxidase and Leukotriene B4 activity. These data demonstrate that depleting the complement system can improve flow and outcome following cerebral ischemia with reperfusion.