Preoperative Chronic Opiate Use and Patient Reported Outcomes Following Adult Spinal Reconstructive Surgery.

BACKGROUND: Preoperative chronic narcotic use has been linked to poor outcomes after surgery for degenerative spinal disorders in the form of lower health-related quality of life scores, higher revision rates, increased infections, lower likelihood of return to work, and higher 90-day readmission rates. This study evaluated the impact of preoperative chronic narcotic use on patient reported outcome measures following adult spinal reconstructive surgery. METHODS: Patients who underwent adult spinal reconstructive surgery over 2 years at our institution were identified from a prospectively maintained spine registry. These patients were grouped into chronic opiate users as defined by a 6-month duration of use with a minimum morphine equivalent dose of 30 mg/day. Patient reported outcome measures were collected prospectively. RESULTS: Of 140 patients included for analysis, 30 (21.4%) patients were categorized as chronic opiate users. No differences were identified in mean preoperative patient reported outcome measures, including Oswestry Disability Index, health state, visual analog scale, and EQ-5D indices. At both 6 weeks and 6 months postoperatively, patients in the opiate group demonstrated significantly worse mean visual analog scale back pain scores relative to the nonopiate group. At 6 months postoperatively and at the last known clinical follow-up, Oswestry Disability Index scores were higher in the opiate group. CONCLUSIONS: Chronic opiate use before adult spinal reconstructive surgery was associated with worse pain and disability following intervention. Further work is needed to understand the role of opiate weaning as part of a larger prehabilitation strategy for adult spinal reconstructive surgery.

Impact of endplate-implant area mismatch on rates and grades of subsidence following stand-alone lateral lumbar interbody fusion: an analysis of 623 levels.

OBJECTIVE: Stand-alone lateral lumbar interbody fusion (LLIF) is a useful minimally invasive approach for select spinal disorders, but implant subsidence may occur in up to 30% of patients. Previous studies have suggested that wider implants reduce the subsidence rate. This study aimed to evaluate whether a mismatch of the endplate and implant area can predict the rate and grade of implant subsidence. METHODS: The authors conducted a retrospective review of prospectively collected data on consecutive patients who underwent stand-alone LLIF between July 2008 and June 2015; 297 patients (623 surgical levels) met inclusion criteria. Imaging studies were examined to grade graft subsidence according to Marchi criteria. Thirty patients had radiographic evidence of implant subsidence. The endplates above and below the implant were measured. RESULTS: A total of 30 patients with implant subsidence were identified. Of these patients, 6 had Marchi grade 0, 4 had grade I, 12 had grade II, and 8 had grade III implant subsidence. There was no statistically significant correlation between the endplate-implant area mismatch and subsidence grade or incidence. There was also no correlation between endplate-implant width and length mismatch and subsidence grade or incidence. However, there was a strong correlation between the usage of the 18-mm-wide implants and the development of higher-grade subsidence (p = 0.002) necessitating surgery. There was no significant association between the degree of mismatch or Marchi subsidence grade and the presence of postoperative radiculopathy. Of the 8 patients with 18-mm implants demonstrating radiographic subsidence, 5 (62.5%) required reoperation. Of the 22 patients with 22-mm implants demonstrating radiographic subsidence, 13 (59.1%) required reoperation. CONCLUSIONS: There was no correlation between endplate-implant area, width, or length mismatch and Marchi subsidence grade for stand-alone LLIF. There was also no correlation between either endplate-implant mismatch or Marchi subsidence grade and postoperative radiculopathy. The data do suggest that the use of 18-mm-wide implants in stand-alone LLIF may increase the risk of developing high-grade subsidence necessitating reoperation compared to the use of 22-mm-wide implants.

Republished: Intracranial vessel occlusion preceding the development of mycotic aneurysms in patients with endocarditis.

Mycotic aneurysms (MA) are an uncommon complication of infectious endocarditis. Septic emboli are thought to be the precipitating event in their development, but the evidence for this is sparse. We present three cases in which septic embolic occlusion preceded MA development at the occlusion site, suggesting that documented angiographic emboli in patients with infectious endocarditis and bacteremia constitute a risk factor for MA formation. Two adult patients with a history of intravenous drug use and one child with congenital heart disease are described. They were all diagnosed with infectious endocarditis and developed neurological symptoms during their hospital course. Initial catheter-based cerebral angiograms demonstrated vascular occlusions, which were followed by the development of MA at the same sites within 1 month. Septic emboli, documented on cerebral angiogram, in patients with infectious endocarditis may precede the appearance of MA. Patients with angiographic occlusions in the setting of endocarditis warrant close follow-up.

Middle Meningeal Artery Embolization for the Treatment of an Expanding Epidural Hematoma.

INTRODUCTION: Epidural hematomas (EHs) usually originate from traumatic injury to the middle meningeal artery (MMA). Although large EHs may need to be emergently evacuated, the management of smaller EHs is less clear, especially in the absence of significant mass effect or neurologic deficits. Endovascular treatment via MMA embolization for epidural hematomas has only been recently reported. Herein, we present a case whereby MMA embolization was performed to prevent further growth of an expanding, right-sided EH after a larger left EH was surgically evacuated. CASE DESCRIPTION: A 31-year-old male patient was brought to the emergency department after he was found down by the police at his house. He was initially conversant but quickly became obtunded within a few minutes. An initial scan showed bilateral (left larger than right) acute EHs, and the patient was taken to the operating room for a left craniotomy. Immediate postoperative imaging demonstrated an expanding right-sided EH. The patient was emergently taken to the endovascular suite and obvious contrast extravasation was noticed from the parietal branch of the MMA. The MMA was embolized via a transradial approach. Follow-up imaging revealed stable hematoma size without the need for additional surgery. The patient was discharged without any neurologic deficits. CONCLUSIONS: Herein, we report the successful endovascular treatment of an expanding EH following a contralateral craniotomy. Active bleeding of the MMA was observed via angiography and may predict further EH expansion. Endovascular exploration and possible treatment can be justified in patients with EH that do not have a clear surgical indication.

Intracranial vessel occlusion preceding the development of mycotic aneurysms in patients with endocarditis.

Mycotic aneurysms (MA) are an uncommon complication of infectious endocarditis. Septic emboli are thought to be the precipitating event in their development, but the evidence for this is sparse. We present three cases in which septic embolic occlusion preceded MA development at the occlusion site, suggesting that documented angiographic emboli in patients with infectious endocarditis and bacteremia constitute a risk factor for MA formation. Two adult patients with a history of intravenous drug use and one child with congenital heart disease are described. They were all diagnosed with infectious endocarditis and developed neurological symptoms during their hospital course. Initial catheter-based cerebral angiograms demonstrated vascular occlusions, which were followed by the development of MA at the same sites within 1 month. Septic emboli, documented on cerebral angiogram, in patients with infectious endocarditis may precede the appearance of MA. Patients with angiographic occlusions in the setting of endocarditis warrant close follow-up.

Low preoperative serum prealbumin levels and the postoperative surgical site infection risk in elective spine surgery: a consecutive series.

OBJECTIVENutritional deficiency negatively affects outcomes in many health conditions. In spine surgery, evidence linking preoperative nutritional deficiency to postoperative surgical site infection (SSI) has been limited to small retrospective studies. Authors of the current study analyzed a large consecutive cohort of patients who had undergone elective spine surgery to determine the relationship between a serum biomarker of nutritional status (preoperative prealbumin levels) and SSI.METHODSThe authors conducted a retrospective review of the electronic medical charts of patients who had undergone posterior spinal surgeries and whose preoperative prealbumin level was available. Additional data pertinent to the risk of SSI were also collected. Patients who developed a postoperative SSI were identified, and risk factors for postoperative SSI were analyzed. Nutritional deficiency was defined as a preoperative serum prealbumin level ≤ 20 mg/dl.RESULTSAmong a consecutive series of 387 patients who met the study criteria for inclusion, the infection rate for those with preoperative prealbumin ≤ 20 mg/dl was 17.8% (13/73), versus 4.8% (15/314) for those with preoperative prealbumin > 20 mg/dl. On univariate and multivariate analysis a low preoperative prealbumin level was a risk factor for postoperative SSI with a crude OR of 4.29 (p < 0.01) and an adjusted OR of 3.28 (p = 0.02). In addition, several previously known risk factors for infection, including diabetes, spinal fusion, and number of operative levels, were significant for the development of an SSI.CONCLUSIONSIn this consecutive series, preoperative prealbumin levels, a serum biomarker of nutritional status, correlated with the risk of SSI in elective spine surgery. Prehabilitation before spine surgery, including strategies to improve nutritional status in patients with nutritional deficiencies, may increase value and improve spine care.

Einstein@Home discovers a radio-quiet gamma-ray millisecond pulsar.

Millisecond pulsars (MSPs) are old neutron stars that spin hundreds of times per second and appear to pulsate as their emission beams cross our line of sight. To date, radio pulsations have been detected from all rotation-powered MSPs. In an attempt to discover radio-quiet gamma-ray MSPs, we used the aggregated power from the computers of tens of thousands of volunteers participating in the Einstein@Home distributed computing project to search for pulsations from unidentified gamma-ray sources in Fermi Large Area Telescope data. This survey discovered two isolated MSPs, one of which is the only known rotation-powered MSP to remain undetected in radio observations. These gamma-ray MSPs were discovered in completely blind searches without prior constraints from other observations, raising hopes for detecting MSPs from a predicted Galactic bulge population.

An accreting pulsar with extreme properties drives an ultraluminous x-ray source in NGC 5907.

Ultraluminous x-ray sources (ULXs) in nearby galaxies shine brighter than any x-ray source in our Galaxy. ULXs are usually modeled as stellar-mass black holes (BHs) accreting at very high rates or intermediate-mass BHs. We present observations showing that NGC 5907 ULX is instead an x-ray accreting neutron star (NS) with a spin period evolving from 1.43 seconds in 2003 to 1.13 seconds in 2014. It has an isotropic peak luminosity of [Formula: see text]1000 times the Eddington limit for a NS at 17.1 megaparsec. Standard accretion models fail to explain its luminosity, even assuming beamed emission, but a strong multipolar magnetic field can describe its properties. These findings suggest that other extreme ULXs (x-ray luminosity [Formula: see text] 1041 erg second[Formula: see text]) might harbor NSs.

A case of spinal epidural venous malformation with mediastinal extension: management with combined surgery and percutaneous sclerotherapy.

While spinal epidural arteriovenous malformations, fistulas, and shunts are well reported, the presence of a venous malformation in the spinal epidural space is a rare phenomenon. Herein, the authors report the clinical presentation, imaging findings, pathological features, and the outcome of surgical and percutaneous interventional management of a mediastinal and spinal epidural venous malformation in a young woman who presented clinically with neurogenic claudication from presumed venous hypertension precipitating the formation of a syrinx. The patient underwent a C6-T5 osteoplastic laminectomy for decompression of the spinal canal and subtotal resection of the epidural venous malformation, followed by percutaneous sclerotherapy of the mediastinal and residual anterior spinal venous malformation. She developed transient loss of dorsal column sensation, which returned to baseline within 3 weeks of the surgery. A 6-month postoperative MRI study revealed complete resolution of the syrinx and the mediastinal venous malformation. Twelve months after the surgery, the patient has had resolution of all neurological symptoms with the exception of her premorbid migraine headaches. A multidisciplinary approach with partial resection and the use of percutaneous sclerotherapy for the residual malformation can be used to successfully treat a complex venous malformation.

Preoperative prealbumin level as a risk factor for surgical site infection following elective spine surgery.

BACKGROUND: Nutritional status is a critical factor in patient outcomes in a variety of medical contexts. In the surgical fields, there is substantial evidence suggesting that clinical outcomes including infection risk and surgical efficacy may be affected by preoperative nutritional status. The purpose of this study is to evaluate preoperative serum prealbumin levels, the currently preferred serum biomarker of nutritional deficiency, in relation to the risk of developing a surgical site infection. METHODS: A retrospective case-control series was conducted comparing prospectively collected preadmission serum prealbumin levels to the risk for surgical site infection following elective spine surgery. The analysis was conducted under an approved institutional quality assurance protocol. Patients were identified by querying the department billing codes for deep wound washouts over a 3-year period. A cohort of 32 patients with preoperative prealbumin levels who underwent spine surgery complicated by postoperative deep tissue infection was identified. This was compared against a case-control cohort of 74 patients who underwent spine surgery and did not experience postoperative infection. Clinical variables included demographic information, body mass index, smoking, diabetes, steroid use, length of the procedure, and length of hospital stay. The data were analyzed using multivariate Cox regression. RESULTS: Two variables: Preoperative prealbumin < 20 and diabetes were both statistically significant predictors for the risk of developing a postoperative infection with hazard ratios of 2.12 (95% confidence interval [CI]: 1.03-4.37) and 2.22 (95% CI: 1.04-4.75), respectively. CONCLUSIONS: Our results reinforce the relationship between preoperative nutritional status and outcomes in elective spine surgery. The data indicate that preoperative prealbumin levels may be useful in risk stratification. Further study is needed to determine whether nutritional supplementation may reduce the risk of infection.

Transosseous cerebrospinal fluid fistula 14 years after Chiari decompression: presentation and management.

The authors report a unique case of a transosseous CSF fistula that was detected more than 10 years after treatment of a symptomatic Chiari I malformation. This lesion initially presented as an intraosseous cystic lesion involving the C-2 vertebra, which was found to communicate freely with the subarachnoid space through a tiny dural opening. Surgical management involved hemilaminectomy and repair of the dural defect followed by reinforcement of the bony defect with demineralized bone matrix. Following closure of the fistula, symptoms of elevated intracranial pressure developed, necessitating a ventriculoperitoneal shunt for CSF diversion.

Enterogenous cyst of the third ventricle.

We present the second case of an enterogenous cyst of the third ventricle. This is a 28-year-old woman who presented with a 2 year history of progressive headaches and memory loss. A cystic lesion of the anterior third ventricle was noted on MRI. The cyst was resected via a transcallosal approach and demonstrated simple cystic morphology lined by ciliated cuboidal epithelium with numerous goblet cells. The presentation was unusual with signs of memory loss presumably due to a mass effect on the fornices. Although uncommon, this entity should be considered in the differential diagnosis of a cystic lesion of the third ventricle.

Results of gamma knife surgery for Cushing's disease.

OBJECT: Cushing's disease is a challenging neuroendocrine disorder. Although resection remains the primary treatment option for most patients, the disease persists if there is residual or recurrent tumor. Stereotactic radiosurgery has been used to treat patients with persistent Cushing's disease after a prior resection. The authors report on the long-term risks and benefits of radiosurgery for Cushing's disease. METHODS: A retrospective review of a prospectively collected database of radiosurgery patients was undertaken at the University of Virginia. All patients with Cushing's disease treated with Gamma Knife surgery (GKS) were identified. Those without at least 12 months of clinical and radiological follow-up were excluded from this analysis. Rates of endocrine remission, tumor control, and adverse events were assessed. Statistical methods were used to identify favorable and unfavorable prognostic factors. RESULTS: Ninety-six patients with the required follow-up data were identified. The mean tumor margin dose was 22 Gy. The median follow-up was 48 months (range 12-209.8 months). At the last follow-up, remission of Cushing's disease occurred in 70% of patients. The median time to remission among all patients was 16.6 months (range 1-165.7 months). The median time to remission in those who had temporarily stopped taking ketoconazole at the time of GKS was 12.6 months, whereas it was 21.8 months in those who continued to receive ketoconazole (p < 0.012). Tumor control was achieved in 98% of patients. New loss of pituitary function occurred in 36% of patients. New or worsening cranial neuropathies developed in 5 patients after GKS, with the most common involving cranial nerves II and III. CONCLUSIONS: Gamma Knife surgery offers a high rate of tumor control and a reasonable rate of endocrine remission in patients with Cushing's disease. The cessation of cortisol-lowering medications around the time of GKS appears to result in a more rapid rate of remission. Delayed hypopituitarism and endocrine recurrence develop in a minority of patients and underscore the need for long-term multidisciplinary follow-up.

Gamma Knife surgery for large vestibular schwannomas: a single-center retrospective case-matched comparison assessing the effect of lesion size.

OBJECT: Gamma Knife surgery (GKS) is a safe and effective treatment for patients with small to moderately sized vestibular schwannomas (VSs). Reports of stereotactic radiosurgery for large VSs have demonstrated worse tumor control and preservation of neurological function. The authors endeavored to assess the effect of size of VSs treated using GKS. METHODS: This study was a retrospective comparison of 24 patients with large VSs (> 3 cm in maximum diameter) treated with GKS compared with 49 small VSs (≤ 3 cm) matched for age, sex, radiosurgical margin and maximal doses, length of follow-up, and indication. RESULTS: Actuarial tumor progression-free survival (PFS) for the large VS cohort was 95.2% and 81.8% at 3 and 5 years, respectively, compared with 97% and 90% for small VSs (p = 0.009). Overall clinical outcome was better in small VSs compared with large VSs (p < 0.001). Patients with small VSs presenting with House-Brackmann Grade I (good facial function) had better neurological outcomes compared with patients with large VSs (p = 0.003). Treatment failure occurred in 6 patients with large VSs; 3 each were treated with resection or repeat GKS. Treatment failure did not occur in the small VS group. Two patients in the large VS group required ventriculoperitoneal shunt placement. Univariate analysis did not identify any predictors of treatment failure among the large VS cohort. CONCLUSIONS: Patients with large VSs treated using GKS had shorter PFS and worse clinical outcomes compared with age-, sex-, and indication-matched patients with small VSs. Nevertheless, GKS has efficacy for some patients with large VSs and represents a reasonable treatment option for selected patients.

Gamma Knife surgery for the treatment of patients with asymptomatic meningiomas.

OBJECT: Increasingly, meningiomas are detected incidentally, prior to symptom development. While these lesions are traditionally managed conservatively until symptoms develop or lesion growth occurs, it is conceivable that patients at high risk for symptom development may benefit from earlier intervention prior to the appearance of symptoms. However, little research has been performed to determine whether Gamma Knife surgery (GKS) can alter the rate of symptom development in such patients. METHODS: A retrospective case study was performed by screening the University of Virginia GKS database for patients treated for asymptomatic meningiomas. From the patient's medical records, pertinent demographic and treatment information was obtained. Yearly follow-up MRI had been performed to assess tumor control and detect signs of radiation-induced injury. Clinical follow-up via neurological examination had been performed to assess symptom development. RESULTS: Forty-two patients, 33 females (78.6%) and 9 males (21.4%), with 42 asymptomatic meningiomas were included in the analysis. The median age at GKS was 53 years. The most common lesion location was the cerebral convexities (10 lesions [23.8%]), and the median lesion size was 4.0 ml. The median duration of imaging and clinical follow-ups was 59 and 76 months, respectively. During the follow-up period, 1 tumor (2.4%) increased in size, 2 patients (4.8%) demonstrated symptoms, and 1 patient (2.4%) exhibited possible signs of radiation-induced injury. Thus, actuarial tumor control rates were 100%, 95.7%, and 95.7% for 2, 5, and 10 years, respectively. Actuarial symptom control at 5 and 10 years was 97% and 93.1%, respectively. Overall progression-free survival was 91.1% and 77.8% at 5 and 10 years, respectively. CONCLUSIONS: Compared with published rates of symptom development in patients with untreated meningiomas, results in this study indicated that patients with asymptomatic lesions may benefit from prophylactic radiosurgery prior to the appearance of symptoms. Additionally, GKS is a treatment option that offers low morbidity.

Gamma Knife surgery for the treatment of 5 to 15 metastases to the brain: clinical article.

OBJECT: It has been generally accepted that Gamma Knife surgery (GKS) is an effective primary or adjunct treatment for patients with 1-4 metastases to the brain. The number of studies detailing the use of GKS for 5 or more brain metastases, however, remains minimal. The aim of the current retrospective study was to elucidate the utility of GKS in patients with 5-15 brain metastases. METHODS: Patients were chosen for GKS based on prior MRI of these metastatic lesions and a known primary cancer diagnosis. Magnetic resonance imaging was used post-GKS to assess tumor control; patients were also followed up clinically. Overall survival (OS) from the date of GKS was used as the primary end point. Statistical analysis was performed to identify prognostic factors related to OS. RESULTS: Between 2003 and 2012, 96 patients were treated for a total of 704 metastatic brain lesions. The histology of these lesions varied among non-small cell lung cancer (NSCLC), breast cancer, melanoma, renal cancer, and other more rare carcinomas. At the initial treatment, 18 of the patients (18.8%) were categorized in Recursive Partitioning Analysis (RPA) Class 1 and 77 (80.2%) in RPA Class 2; none were in RPA Class 3. The median number of treated lesions was 7 (mean 7.13), and the median planned treatment volume was 6.12 cm(3) (range 0.42-57.83 cm(3)) per patient. The median clinical follow-up was 4.1 months (range 0.1-40.70 months). Actuarial tumor control was calculated to be 92.4% at 6 months, 84.8% at 12 months, and 74.9% at 24 months post-GKS. The median OS was found to be 4.73 months (range 0.4-41.8 months). Multivariate analysis demonstrated that RPA class was a significant predictor of death (HR = 2.263, p = 0.038). Number of lesions, tumor histology, Graded Prognostic Assessment score, prior whole-brain radiation therapy, prior resection, prior chemotherapy, patient age, patient sex, controlled primary tumor, extracranial metastases, and planned treatment volume were not significant predictors of OS. CONCLUSIONS: In patients with 5-15 brain metastases at presentation, the number of lesions did not predict survival after GKS; however, the RPA class was predictive of OS in this group of patients. Gamma Knife surgery for such patients offers an excellent rate of local tumor control.

Stereotactic radiosurgery for WHO II and III meningiomas: analysis of long-term clinical and radiographic outcomes.

BACKGROUND/AIM: WHO grade II and III meningiomas are challenging tumors to treat, and the role of stereotactic radiosurgery (SRS) in their treatment is not well defined. We evaluate our experience to better define its role and assess for clinical and radiographic predictors of failure. METHODS: This is a retrospective analysis of all patients with histological diagnosis of WHO II or III meningioma. Thirteen patients were included. The mean dose to the periphery was 16 Gy (12-20), the mean maximum dose was 31 Gy (13-40), and the mean isodose line was 49% (35-50). RESULTS: The median age was 48 years. The median follow up was 50 months (7-67). All cases had undergone at least one previous resection, and six patients had undergone external beam radiation (EBRT). The median pre SRS Karnofsky performance score (KPS) was 90. The progression free survival (PFS) was 92% and 31% at 1 and 4 years, respectively. Eleven patients required further treatment after SRS. The final tumor volume was decreased in 7 patients, stable in 1, and increased in 6. CONCLUSIONS: WHO grade II and III meningiomas are aggressive tumors that will require multiple treatments. SRS may be a useful as an adjuvant treatment or for recurrence.

Design and validation of a compressive tissue stimulator with high-throughput capacity and real-time modulus measurement capability.

Mechanical stimulation has been shown to impact the properties of engineered hyaline cartilage constructs and is relevant for engineering of cartilage and osteochondral tissues. Most mechanical stimulators developed to date emphasize precision over adaptability to standard tissue culture equipment and protocols. The realization of mechanical characteristics in engineered constructs approaching native cartilage requires the optimization of complex variables (type of stimulus, regimen, and bimolecular signals). We have proposed and validated a stimulator design that focuses on high construct capacity, compatibility with tissue culture plastic ware, and regimen adaptability to maximize throughput. This design utilizes thin force sensors in lieu of a load cell and a linear encoder to verify position. The implementation of an individual force sensor for each sample enables the measurement of Young's modulus while stimulating the sample. Removable and interchangeable Teflon plungers mounted using neodymium magnets contact each sample. Variations in plunger height and design can vary the strain and force type on individual samples. This allows for the evaluation of a myriad of culture conditions and regimens simultaneously. The system was validated using contact accuracy, and Young's modulus measurements range as key parameters. Contact accuracy for the system was excellent within 1.16% error of the construct height in comparison to measurements made with a micrometer. Biomaterials ranging from bioceramics (cancellous bone, 123 MPa) to soft gels (1% agarose, 20 KPa) can be measured without any modification to the device. The accuracy of measurements in conjunction with the wide range of moduli tested demonstrate the unique characteristics of the device and the feasibility of using this device in mapping real-time changes to Young's modulus of tissue constructs (cartilage, bone) through the developmental phases in ex vivo culture conditions.

An automated algorithm to improve the precision of basilar artery diameter measurements before and after subarachnoid hemorrhage-induced vasospasm in an animal model.

OBJECTIVE: Quantifying vasospasm has traditionally been performed manually, a method prone to imprecision and user bias. An alternative approach is to use computerized image analysis techniques to define and quantify the diameter of a vessel. The goal of this article is to demonstrate a novel automated vessel measurement algorithm specific to the needs of vasospasm studies and to compare it with traditional manual measurements in an animal model of vasospasm. METHODS: A total of 576 arterial diameter measurements were collected by 4 independent, blinded examiners from 24 angiograms in a rabbit subarachnoid hemorrhage (SAH) model. Measurements were taken from 3 segments of the basilar artery in anteroposterior and lateral projections, both before SAH and after SAH-induced vasospasm. Means and standard deviations of 288 manual measurements were compared with 288 automated measurements. RESULTS: The precision of automated measurements was significantly improved compared with standardized manual measurements (85.7% decrease in variation; P < .001). When using automated measurements, the precision was not affected by vessel size, but when using manual measurements, smaller arteries were less precise (P = .04). There was no significant difference in precision between 2 different contrast concentrations (P = .32). CONCLUSION: Automated measurements of basilar artery diameters are more precise than manual measurements, both before and after SAH-induced vasospasm. The variability in the manual group worsens when the artery is smaller secondary to vasospasm, indicating a need for the use of this segmentation method.