Predictors of functional outcome vary by the hemisphere of involvement in major ischemic stroke treated with intra-arterial therapy: a retrospective cohort study.

BACKGROUND: Conflicting data exists regarding the effect of hemispheric lateralization on acute ischemic stroke outcome. Some of this variability may be related to heterogeneous study populations, particularly with respect to the level of arterial occlusion. Furthermore, little is known about the relationship between stroke lateralization and predictors of outcome. The purpose of this study was to characterize the impact of stroke lateralization on both functional outcome and its predictors in a well-defined population of anterior circulation proximal artery occlusions treated with IAT. METHODS: Thirty-five consecutive left- and 35 consecutive right-sided stroke patients with intracranial ICA and/or MCA occlusions who underwent IAT were retrospectively analyzed. Ischemic change on pre-treatment imaging was quantified. Reperfusion success was graded using the Mori scale. Good outcome at three months was defined as an mRS

Comparison of ruptured vs unruptured aneurysms in recanalization after coil embolization.

BACKGROUND: Aneurysm recanalization is a significant problem in coil-treated intracranial aneurysms. We hypothesize ruptured aneurysms are more likely to demonstrate this phenomenon than unruptured aneurysms. METHODS: This was a retrospective study over 4 years. Initial and follow-up angiography results were reviewed and aneurysm obliteration was classified: I, complete; II, residual neck; III, residual aneurysm; and IV, partial treatment. Recanalization was classified as significant, mild, and none. RESULTS: Two hundred twelve aneurysms were coiled in 199 patients, of which 180 patients survived to 6 months after treatment. Follow-up angiography (>6 months) was available for 116 (64.4%) aneurysms (44 ruptured, 72 unruptured). Mean angiographic follow-up was 20 months. Recanalization was significant in 16 (13.8%) aneurysms, mild in 23 (19.8%), and absent in 87 (75%). Sixteen aneurysms underwent recoiling. Factors significant for recanalization by univariate analysis were ruptured vs unruptured (53.5% vs 22.5%; P = .001), larger aneurysm size (t test, P < .0001; median, 8-mm cut point, P < .01), aneurysm location (basilar tip and ICA terminus, P < .05), posterior circulation (P < .05), and younger age (t test, P < .05), whereas aneurysm neck size (4 mm) demonstrated a trend (P = .09). Incomplete initial aneurysm obliteration (II-IV, 20.6% vs I, 4.3%; P < .05) was associated with significant recanalization. In multivariate analysis, younger age (age <52 years; OR, 2.4; 95% CI, 0.194-2.08), ruptured aneurysm (OR, 3.2; 95% CI, 1.25-8.13), and larger aneurysm size (OR, 1.14; 95% CI, 1.04-1.24 linearly; OR, 3.5; 95% CI, 1.38-8.72) significantly predicted aneurysm recanalization. Performance of recoiling was significant with larger aneurysm size (OR, 2.0; 95% CI, 0.02-3.25) and younger age (age <52, OR, 2.4; 95% CI, 0.34-3.31) by multivariate analysis, whereas ruptured aneurysm demonstrated a trend. CONCLUSIONS: In multivariate analyses, ruptured aneurysms, larger aneurysms, and younger patient age were significantly associated with recanalization. Larger aneurysms and younger age were significantly associated with recoiling.

Vertebral augmentation complicated by perioperative addisonian crisis.

BACKGROUND: We describe a case of perioperative Addisonian crisis induced by vertebral augmentation. While several complications of vertebral augmentation have been reported previously, related to the technical procedure, to our knowledge, perioperative Addisonian crisis from vertebral augmentation has not been reported in the literature. OBJECTIVE: To report an Addisonian crisis perioperative to vertebral augmentation. DESIGN: Case report. METHOD: Retrospective case review. RESULTS: The patient had a history of adrenal insufficiency treated previously with steroids. He developed an L3 vertebral compression fracture, failed conservative therapy and was eventually referred for vertebral augmentation. Immediately after starting the procedure, the patient developed profound hypotension unresponsive to intravenous fluids and vasopressors, consistent with Addisonian crisis. After intravenous steroids had resolved the Addisonian crisis, he underwent vertebral augmentation without further complication. CONCLUSION: Addisonian crisis may be triggered by vertebral augmentation. Practitioners need to recognize immediately this potentially lethal disorder in patients with known or suspected adrenal insufficiency and treat with intravenous hydrocortisone.

Kyphoplasty for vertebral compression fracture via a uni-pedicular approach.

BACKGROUND: Percutaneous kyphoplasty using a bone expander polymer device, such as percutaneous vertebroplasty and balloon kyphoplasty, is a therapeutic intervention for painful osteoporotic vertebral body compression fractures. Typically the procedure involves placement of bilateral Sky Bone Expanders in the fractured vertebral body via a transpedicular approach. We describe performance of "SKy"phoplasty using the Disc-O-Tech Sky Bone Expander (Disc-O-Tech Medical Technologies, Herzliya, Israel, and Monroe Township, New Jersey) via a unilateral transpedicular approach. The advantage of a unilateral approach is that it reduces the risks associated with large-bore needle placement. These risks include pedicle fracture, medial transgression of the pedicle or transgression into the spinal canal, nerve injury, cement leakage along the cannula tract, and spinal epidural hematoma. Additionally, using a unilateral approach reduces operative time and costs. CASE ILLUSTRATION: A 68-year-old man with osteoporosis presented with severe upper back pain which occurred following a fall. The pain was reproducible on palpation of the L1 spinous process. A lumbar spine magnetic resonance imaging (MRI) with STIR (short tau inversion recovery) sequence demonstrated an acute L1 vertebral body compression fracture. A L1 "SKy"phoplasty was performed using a single Sky Bone Expander polymer device via a unilateral transpedicular approach. The patient reported immediate relief of pain after the procedure. He denied any residual back pain at his follow-up visit. He was able to resume his normal activities including walking, which had been inhibited by pain prior to the procedure. CONCLUSION: "SKy"phoplasty can be performed using a single Sky Bone Expander via a unilateral pedicular approach. The key is a medial needle trajectory with a final Sky Bone Expander position in the midline of the vertebral body.

CT angiography before embolization for hemorrhage in head and neck cancer.

We present a patient with advanced head and neck carcinoma and a bleeding pseudoaneurysm diagnosed by means of CT angiography; this was not apparent on conventional digital subtraction angiograms. The information provided by CT angiography facilitated rapid identification of the pseudoaneurysm and treatment with embolization. CT angiography may be helpful before embolization in cases of hemorrhage in head and neck cancer.

In-hospital morbidity and mortality after endovascular treatment of unruptured intracranial aneurysms in the United States, 1996-2000: effect of hospital and physician volume.

BACKGROUND AND PURPOSE: Endovascular therapy is increasingly being used for the treatment of unruptured intracranial aneurysms. Our purpose was to determine the risk of adverse outcomes after contemporary endovascular treatment of unruptured intracranial aneurysms in the United States. Patient, treating physician, and hospital characteristics were tested as potential outcome predictors, with particular attention paid to volume of care. METHODS: We conducted a retrospective cohort study by using the Nationwide Inpatient Sample, 1996-2000. Multivariate logistic and ordinal regressions were used with end points of mortality, discharge other than to home, length of stay, and total hospital charges. RESULTS: Four hundred twenty-one patients underwent endovascular treatment at 81 hospitals. The in-hospital mortality rate was 1.7%, and 7.6% were discharged to institutions other than home. Analysis was adjusted for age, sex, race, primary payer, year of treatment, and four variables measuring acuity of treatment and medical comorbidity. Median annual number of unruptured aneurysms treated was nine per hospital and three per treating physician. Higher volume hospitals had fewer adverse outcomes; discharge other than to home occurred after 5.2% of operations at high volume hospitals (>23 admissions per year) compared with 17.6% at low volume hospitals (fewer than four admissions per year) (P<.001). Higher physician volume had a similar effect (0% versus 16.4%, P=.03). The mortality rate was lower at high volume hospitals (1.0% versus 3.7%) but not significantly so. At high volume hospitals, length of stay was shorter (P<.001) and total hospital charges were lower (P<.001). CONCLUSION: For patients with unruptured aneurysms treated in the United States from 1996 to 2000, endovascular treatment at high volume institutions or by high volume physicians was associated with significantly lower morbidity rates and modestly lower mortality rates. Length of stay was shorter and total hospital charges lower at high volume centers.

Preliminary experience with intra-arterial nicardipine as a treatment for cerebral vasospasm.

BACKGROUND AND PURPOSE: Papaverine is the primary intra-arterial (IA) treatment for vasospasm after aneurysmal subarachnoid hemorrhage (SAH); however, is it limited in effect and by adverse effects. We prospectively studied the use of IA nicardipine as a treatment for vasospasm. METHODS: Over 12 months, all patients with SAH who required interventional treatment for vasospasm were given IA nicardipine with or without angioplasty. Vasospasm was determined by serial clinical assessments and/or daily transcranial Doppler (TCD) imaging and confirmed by angiography. Doses of IA nicardipine per vessel were 0.5-6 mg. All patients were monitored for increased intracranial pressure (ICP) and change in cardiovascular or neurologic status. RESULTS: Forty-four vessels in 18 patients with vasospasm were treated with IA nicardipine alone. TCD data for 38 vessels (15 cases) were available. All vessels demonstrated immediate angiographic dilatation after IA nicardipine. No sustained cardiovascular changes were after treatment. ICP was transiently elevated in five patients and persistently elevated in one. Mean peak systolic velocities at TCD imaging were significantly reduced from pretreatment values in all treated vessels for 4 days after infusion (268.9 +/- 77.8 vs 197.6 +/- 74.1 cm/s, P <.001). Neurologic improvement after IA nicardipine occurred in eight (42.1%) patients. No clinical deterioration was noted. CONCLUSION: As shown by TCD imaging, IA nicardipine has an immediate and sustained effect on vasospasm. It does not appear to have sustained effect on ICP or cardiovascular status. This treatment warrants further study to determine its safety and efficacy.

Persistent nonfused segments of the basilar artery: longitudinal versus axial nonfusion.

Embryologic development of the basilar artery occurs along two axis systems: longitudinal fusion and axial fusion. Longitudinal fusion consists of midline fusion of paired ventral arteries and reflects the simplified pattern of arterial anatomy found in the spinal cord. Axial fusion consists of fusion of the distal basilar artery, which arises from the caudal division of the internal carotid artery, to the midbasilar agenesis to the posterior inferior cerebellar artery termination of the vertebral arteries. Persistent longitudinal nonfusion (or complete duplication) of the basilar artery is very rare, and persistent axial nonfusion is even rarer. We report one case of persistent longitudinal nonfusion of the basilar artery in a 3-year-old boy and a case of persistent axial nonfusion of the basilar artery in a 43-year-old man.

Results of a prospective protocol of computed tomographic angiography in place of catheter angiography as the only diagnostic and pretreatment planning study for cerebral aneurysms by a combined neurovascular team.

OBJECTIVE: At many centers, patients undergo both computed tomographic angiography (CTA) and digital subtraction angiography (DSA). This practice negates most of the advantages of CTA, and it renders the risks and disadvantages of the two techniques additive. Previous reports in the literature have assessed the sensitivity and specificity of CTA compared with DSA; however, these investigations have not analyzed the clinical implications of a protocol that replaces DSA with CTA as the only diagnostic and pretreatment planning study for patients with cerebral aneurysms. METHODS: Since late 2001/early 2002, the combined neurovascular unit of the Massachusetts General Hospital has adopted a prospective protocol of CTA in place of DSA as the only diagnostic and pretreatment planning study for patients with cerebral aneurysms (ruptured and unruptured). We report the results obtained during the 12-month period from January 2002 to January 2003. RESULTS: During the study period, 223 patients with cerebral aneurysms underwent initial diagnostic evaluation for cerebral aneurysm by the combined neurovascular team of Massachusetts General Hospital. Of the 223 patients, 109 patients had confirmed subarachnoid hemorrhage (Group A) and 114 patients did not have SAH (Group B). All of these patients were included in the prospective CTA protocol. Cerebral aneurysm treatment was initiated on the basis of CTA alone in 93 Group A patients (86%), in 89 Group B patients (78%), and in 182 patients (82%) overall. Treatment consisted of surgical clipping in 152 patients (68%), endovascular coiling in 56 patients (25%), endovascular parent artery balloon occlusion in 4 patients (2%), and external carotid artery to internal carotid artery bypass and carotid artery surgical occlusion in 2 patients (1%). Nine patients (4%) did not undergo treatment. The cerebral aneurysm detection rate by CTA was 100% for the presenting aneurysm (ruptured aneurysm in Group A or symptomatic/presenting aneurysm in Group B) in both groups. The detection rate by CTA for total cerebral aneurysms, including incidental multiple aneurysms, was 95.3% in Group A, 98.3% in Group B, and 97% overall. The overall morbidity associated with DSA (pretreatment or as intraoperative or postoperative clip evaluation) was one patient (1.3%) with a minor nonneurological complication, one patient (1.3%) with a minor neurological complication, and no patients (0%) with a major neurological complication. CONCLUSION: We have demonstrated promising results with a prospective protocol of CTA in place of DSA as the only diagnostic and pretreatment planning study for patients with ruptured and unruptured cerebral aneurysms. It seems safe and effective to make decisions regarding treatment on the basis of CTA, without performing DSA, in the majority of patients with ruptured and unruptured cerebral aneurysms.

Age-dependent differences in short-term outcome after surgical or endovascular treatment of unruptured intracranial aneurysms in the United States, 1996-2000.

INTRODUCTION: Unruptured intracranial aneurysm patients are frequently eligible for both open surgery ("clipping") and endovascular repair ("coiling"). We compared short-term end points (mortality, discharge disposition, complications, length of stay, and charges) for clipping and coiling in a nationally representative discharge database. METHODS: We conducted a retrospective cohort study using Nationwide Inpatient Sample data from 1996 to 2000. Multivariate logistic regression analyses adjusted for age, sex, race, payer status, geographic region, presenting signs and symptoms, admission type and source, procedure timing, hospital caseload, and possible clustering of outcomes within hospitals. The results were confirmed by performing propensity score analysis. RESULTS: A total of 3498 patients had clipping, and 421 underwent coiling. Clipped patients were slightly younger (P < 0.001). Medical comorbidity was similar between the groups. More clipped patients had urgent or emergency admissions (P = 0.02). More coiling procedures were performed on hospital Day 1 (P = 0.007). When only death and discharge to long-term care were counted as adverse outcomes, there was no significant difference between clipping and coiling. On the basis of a four-level discharge status outcome scale (dead, long-term care, short-term rehabilitation, or discharge to home), coiled patients had a significantly better discharge disposition (odds ratio, 2.1; P < 0.001). With regard to patient age, most of the difference in discharge disposition was in patients older than 65 years of age. The degree of difference between treatments increased from 1996 to 2000. Neurological complications were coded twice as frequently in clipped patients as in coiled patients (P = 0.002). Length of stay was longer (5 d versus 2 d, P < 0.001) and charges were higher ($21,800 versus $13,200, P = 0.007) for clipped patients than for coiled patients. CONCLUSION: There was no significant difference in mortality rates or discharge to long-term facilities after clipping or coiling of unruptured aneurysms. When discharge to short-term rehabilitation was counted as an adverse event, coiled patients had significantly better outcomes than clipped patients at the time of hospital discharge, but most of the coiling advantage was concentrated in patients older than 65 years of age. Even in older patients, long-term end points-including long-term functional status in patients discharged to rehabilitation and efficacy in preventing hemorrhage-will be critical in determining the best treatment option for patients with unruptured aneurysms.

Balloon kyphoplasty for vertebral compression fracture using a unilateral balloon tamp via a uni-pedicular approach: technical note.

OBJECTIVE: Percutaneous balloon kyphoplasty, like percutaneous vertebroplasty is a therapeutic intervention for painful osteoporotic vertebral body compression fracture. The procedure involves placement of bilateral inflatable balloon tamps in the fractured vertebral body via a bilateral transpedicular or bilateral extra-pedicular approach. We describe performance of balloon kyphoplasty using a unilateral, single, balloon tamp via a unilateral transpedicular approach. The advantages of a unilateral approach are reducing the risk, albeit low, of pedicle fracture, medial transgression of the pedicle and/or transgression into the spinal canal, nerve injury, cement extravasation along the cannula tract, and spinal epidural hematoma. Additionally, operative and anesthesia time is reduced, as well as the costs of balloon tamps, cannulas, and needles. CASE ILLUSTRATION: An 83-year-old woman with osteoporosis presented with severe lower thoracic back pain which occurred when she bent over to lift a heavy box. The pain was reproducible on palpation of the T-11 spinous process. A spine MRI with STIR (short tau inversion recovery) sequence demonstrated a subacute T-11 vertebral body compression fracture with associated edema. A T-11 balloon kyphoplasty was performed using a unilateral inflatable balloon tamp via a unilateral transpedicular approach. The patient reported immediate relief of pain and improvement of visual analog score (VAS) for pain from preoperative 10 to postoperative 2. She was able to ambulate postoperatively whereas preoperatively she was inhibited by pain. CONCLUSION: Balloon kyphoplasty can be performed using a unilateral balloon tamp via a unilateral pedicular approach. The key is a medial needle trajectory with a final balloon position in the midline of the vertebral body.

Onyx embolization for the endovascular treatment of infectious and traumatic aneurysms involving the cranial and cerebral vasculature.

BACKGROUND: Onyx is a liquid non-adhesive viscous embolic agent ideal for slow targeted injections which is currently approved for the treatment of intracranial aneurysms and arteriovenous malformations. METHODS: We performed a single-center retrospective analysis of consecutive patients who underwent off-label use of Onyx as the single embolic agent for the treatment of traumatic or infectious pseudoaneurysms involving the cerebral or cranial vasculature. RESULTS: A total of nine pseudoaneurysms treated by Onyx embolization were identified. Six of the pseudoaneurysms were post-surgical, one of the pseudoaneurysms was traumatic and two were infectious in nature. The mean pseudoaneurysm size was 5.9 mm (range 2-10 mm). Onyx-34 was used in all cases. Following treatment there was complete exclusion of all pseudoaneurysms including their inflow and outflow zones. CONCLUSIONS: Our experience demonstrates the efficacy and applicability of the use of Onyx in the treatment of complex traumatic and mycotic pseudoaneurysms involving the cerebral and cranial vascular tree.

Onyx embolization for the treatment of spinal dural arteriovenous fistulae: initial experience with long-term follow-up. Technical case report.

OBJECTIVE: Spinal dural arteriovenous fistulae (SDAVF) are the most common variety of spinal vascular malformations. The Onyx liquid embolic system (ev3 Neurovascular, Irvine, CA) was recently approved for the treatment of intracranial arteriovenous malformations, but its use to treat SDAVFs is not yet well established. We report our initial experience with Onyx embolization in the treatment of SDAVFs. METHODS: Retrospective analysis of 3 consecutive patients with SDAVFs who were treated with the Onyx as the single treatment modality was performed. Demographic, clinical, and radiographic presentations as well as long-term outcomes were reviewed. RESULTS: Four procedures were performed in 3 patients. In all cases, transarterial microcatheterization was performed with a Marathon microcatheter (ev3 Neurovascular) and Onyx-18 (ev3 Neurovascular) was used. All 3 patients were men (age, 75-78 years) and presented with progressive myelopathy. Two patients underwent only 1 procedure, with a single pedicle embolized to achieve angiographic cure. In the remaining patient, 2 procedures with embolization through 3 different pedicles from 2 adjacent levels were necessary to achieve angiographic cure. No procedure-related complications were noted. No evidence of residual or recurrent SDAVF was seen on magnetic resonance imaging (mean, 10.6 months; range, 7.1-14.6 months), angiographic (mean, 12.2 months; range, 10.2-14.9 months), or clinical (mean, 13 months; range, 10.2-14.9 months) follow-up examination. CONCLUSION: Our initial experience suggests that the endovascular treatment of SDAVFs with the Onyx is feasible, safe, and highly effective, as it allows for a controlled penetration of the embolic agent into the draining vein. In this small series, we found no evidence of clinical, magnetic resonance imaging, or angiographic recurrence during the long-term follow-up period.

Reversible parkinsonism after treatment of dural arteriovenous fistula.

BACKGROUND AND PURPOSE: The most common causes of parkinsonism are degenerative and irreversible. Structural causes of reversible parkinsonism are exceptionally rare, but have been reported in association with deep cerebral venous thrombosis and dural arteriovenous fistula (DAVF). We now report a case of parkinsonian syndrome reversed by treatment of a dural arteriovenous malformation. METHODS: Case report with retrospective review of relevant clinical, imaging, and treatment data. RESULTS: A 79-year-old man presented with complaints of a slowly progressive parkinsonian syndrome and tinnitus. Brain magnetic resonance imaging (MRI) showed numerous serpiginous flow voids highly suggestive of a vascular malformation. Cerebral angiography revealed a Cognard grade IIa + b left transverse sinus DAVF. The patient underwent combined endovascular and surgical treatment in three stages over a week's time, with total obliteration of the DAVF and complete normalization of his symptoms and neurological examination. CONCLUSION: Although rare, DAVF should always be considered as a potential cause of progressive parkinsonism. This diagnosis is of great importance because of its potential reversibility.

Low-pressure balloon angioplasty with adjuvant pharmacological therapy in patients with acute ischemic stroke caused by intracranial arterial occlusions.

INTRODUCTION: The use of coronary balloons in the cerebral vasculature is limited due to their poor trackability and increased risk of vessel injury. We report our experience using more compliant elastomer balloons for thrombus resistant to intraarterial (IA) pharmacological and mechanical thrombolysis in acute stroke. METHODS: We retrospectively analyzed 12 consecutive patients with an occluded intracranial artery treated with angioplasty using a low-pressure elastomer balloon. Angiograms were graded according to the Thrombolysis in Cerebral Infarction (TICI) and Qureshi grading systems. Outcomes were categorized as independent (modified Rankin scale, mRS, score

High-dose bosentan in the prevention and treatment of subarachnoid hemorrhage-induced cerebral vasospasm: an open-label feasibility study.

OBJECTIVE: To evaluate the safety of high-dosages of the endothelin ET(A/B )receptor antagonist bosentan in SAH patients at high-vasospasm risk. METHODS: Ten Fisher group-3 SAH patients, enrolled within 96 h of ictus, received bosentan in a dose-escalation manner (20, 30, 40 mg/kg/day orally every 4 hours on treatment days 1, 2, and 3 respectively, to a maximum dose of 4000 mg/day), followed by maintenance of the maximum tolerated dose until 14 days post-SAH or vasospasm resolution. Further management followed standard protocols: nimodipine in all patients; daily transcranial Doppler (TCD); "triple-H"/endovascular treatment, as indicated. RESULTS: Two of the ten patients never developed any clinical or TCD signs of vasospasm; the other eight patients exhibited some elevation of TCD velocities during the vasospasm watch period. Four of the eight patients remained asymptomatic; of them, one had only mild elevation on peak systolic velocities, thought to represent hyperemia. The other three were further assessed with CT-angiography; this revealed moderate vasospasm (asymptomatic) in only one patient. The remaining four patients developed symptomatic vasospasm requiring endovascular treatment; two developed cerebral infarction; both had started bosentan relatively later than the other subjects. The most common adverse drug effects were flushing and transient liver enzyme elevations, reversible in all. Two patients had ALT/AST elevations >3x normal limit, requiring bosentan-dose reduction or discontinuation (one case each). CONCLUSION: High-dose bosentan (up to 40 mg/kg/day) appears to be safe in SAH patients at high risk of developing vasospasm. Further studies are required to properly investigate the efficacy of this regimen in the prevention and treatment of SAH-induced vasospasm.

Complications of cerebral arteriovenous malformation embolization: multivariate analysis of predictive factors.

OBJECTIVE: Embolization is an important therapeutic modality in the multidisciplinary management of arteriovenous malformations (AVM); however, prior series have reported a wide variability in overall complication rates caused by embolization (10-50% neurological deficit, 1-4% mortality). In this study, we reviewed our experience with AVM embolization and analyzed factors that might predict complications and clinical outcomes after AVM embolization. METHODS: We analyzed our combined neurovascular unit's results with AVM embolization from 1993 to 2004 for the following outcomes measures: 1) clinically significant complications, 2) technical complications without clinical sequelae, 3) discharge Glasgow Outcome Scale score, and 4) death. To determine embolization efficacy, we analyzed perioperative blood transfusion and rate of AVM obliteration. Univariate and multivariate analyses were performed for patient age, sex, history of rupture, history of seizure, associated aneurysms, AVM size, deep venous drainage, eloquent location, Spetzler-Martin grade, number of embolization stages, number of pedicles embolized, and primary treatment modality. RESULTS: Over an 11 year period, 295 embolization procedures (761 pedicles embolized) were performed in 168 patients with embolization as the primary treatment modality (n = 16) or as an adjunct to surgery (n = 124) or radiosurgery (n = 28). There were a total of 27 complications in this series, of which 11 were clinically significant (6.5% of patients, 3.7% per procedure), and 16 were technical complications (9.5% of patients, 5.4% per procedure). Excellent or good outcomes (Glasgow Outcome Scale > or = 4) were observed in 152 (90.5%) patients. Unfavorable outcomes (Glasgow Outcome Scale 1-3) as a direct result of embolization were both 3.0% at discharge and at follow-up, with a 1.2% embolization-related mortality. In the 124 surgical patients, 96.8% had complete AVM obliteration after initial resection, and 31% received perioperative transfusion (mean 1.4 units packed red blood cells per surgical patient). Predictors of unfavorable outcome caused by embolization by univariate analysis were deep venous drainage (P < 0.05), Spetzler-Martin Grade III to V (P < 0.05), and periprocedural hemorrhage (P < 0.0001) and by multivariate analysis were Spetzler-Martin III to V (odds ratio 10.6, P = 0.03) and periprocedural hemorrhage (odds ratio 17, P = 0.004). CONCLUSION: In a single-center, retrospective, nonrandomized study, 90.5% of patients had excellent or good outcomes after AVM embolization, with a complication rate lower than previously reported. Spetzler-Martin grade III to V and periprocedural hemorrhage were the most important predictive factors in determining outcome after embolization.

Safety of heparinization for cerebral aneurysm coiling soon after external ventriculostomy drain placement.

OBJECTIVE: Our practice has been to heparinize patients for cerebral aneurysm coiling even after recent external ventriculostomy drain (EVD) placement. The current medical literature cites a 12.5% symptomatic hemorrhage rate with heparinization after recent EVD placement. We reviewed our experience to determine our level of safety with this practice. METHODS: A search of our prospectively collected computerized aneurysm database revealed that from February 1998 to February 2004, 356 aneurysms were coiled, of which 119 patients had had recent EVD placement before coiling. During the same time period, 251 subarachnoid hemorrhage patients underwent EVD placement without coiling or heparinization. We reviewed the head computed tomographic scan reports and medical records to determine the incidence of EVD-related hemorrhage in heparinized patients compared with nonheparinized patients. RESULTS: There was only 1 patient in the heparinized group who had a symptomatic EVD-related hemorrhage attributable to heparinization (0.8%) and 11 patients with asymptomatic EVD-related hemorrhage (9.2%). Among the nonheparinized patients, there were 3 patients who had symptomatic EVD-related hemorrhages (1.2%) and 22 patients with asymptomatic EVD-related hemorrhages (8.8%) (P = not significant for both symptomatic and asymptomatic EVD-related hemorrhages). The time interval between EVD placement and heparinization in the heparinized patient with symptomatic EVD-related hemorrhage was 0.5 day; the mean time interval in the heparinized patients with asymptomatic EVD-related hemorrhage was 0.8 day; and in the heparinized patients with no hemorrhage, it was 0.8 day. The peak activated prothrombin time of the heparinized patient with symptomatic EVD-related hemorrhage was >150 seconds, the mean peak activated prothrombin time of the heparinized patients with asymptomatic EVD-related hemorrhage was 73.1 seconds, and that of the heparinized patients with no hemorrhage was 90.3 seconds. CONCLUSION: Heparinization for cerebral aneurysm coiling can be safely performed even after EVD placement within 24 hours, particularly if the activated prothrombin time is kept strictly controlled.

Heparin-induced thrombocytopenia Type II in subarachnoid hemorrhage patients: incidence and complications.

OBJECTIVE: Heparin-induced thrombocytopenia Type II (HIT II) is the autoimmune-mediated severe form of the disease characterized by a significant reduction in platelets, and it carries a high risk of "paradoxical" serious thrombotic complications. Although HIT II has been studied in several different patient populations, the incidence of HIT II and the rate of thrombotic complications have never been reported in a neurosurgical patient population. Subarachnoid hemorrhage (SAH) patients, among neurosurgical patient populations, have a high exposure to heparin because they are in critical care units and have indwelling vascular catheters. In addition, the increase in neuroendovascular procedures with the associated use of heparinization will increase the exposure of SAH patients to heparin. METHODS: During a 3.5-year period (January 2000-June 2003), 389 consecutive SAH patients were treated at our center. We retrospectively reviewed their laboratory data and medical records and used accepted clinical criteria for the diagnosis of HIT II to determine the incidence of HIT II, thrombotic complications, management, and outcome. RESULTS: Fifty-nine patients (15%) met the clinical diagnostic criteria for HIT II. The average platelet count nadir in the HIT II patients was 68,600 +/- 25,300/microl (mean +/- standard deviation). Female patients and patients with Fisher Grade 3 were more likely to develop HIT II (P < 0.01). Thirty-six patients (61%) underwent a neuroendovascular procedure. The rate of systemic thrombotic complications in the HIT II patients was 37 versus 7% in SAH patients without HIT II (P < 0.001), and the rate of new hypodensities on head computed tomographic scans was 66% in the HIT II patients versus 40% in the SAH patients without HIT II (P < 0.001). Clinical outcomes were worse in the HIT II patients. The outcome was favorable for 38% in the HIT II patients versus 52% in all SAH patients (P < 0.05), and deaths were more common (29%) in the HIT II patients than in all SAH patients (12%, P < 0.001). CONCLUSION: The incidence of HIT II in SAH patients at a single center was 15%. The SAH patients with HIT II had significantly higher rates of thrombotic complications, new hypodensities on head computed tomographic scans, more deaths, and significantly less favorable outcomes. This is the first report of the incidence of HIT II in a neurosurgical patient population.