Effect of SARS and COVID-19 outbreaks on urology practice and training.

INTRODUCTION: The objective was to investigate the changes in urology practice during coronavirus disease 2019 (COVID-19) pandemic with a perspective from our experience with severe acute respiratory syndrome (SARS) in 2003. METHODS: Institutional data from all urology centres in the Hong Kong public sector during the COVID-19 pandemic (1 Feb 2020-31 Mar 2020) and a non-COVID-19 control period (1 Feb 2019-31 Mar 2019) were acquired. An online anonymous questionnaire was used to gauge the impact of COVID-19 on resident training. The clinical output of tertiary centres was compared with data from the SARS period. RESULTS: The numbers of operating sessions, clinic attendance, cystoscopy sessions, prostate biopsy, and shockwave lithotripsy sessions were reduced by 40.5%, 28.5%, 49.6%, 44.8%, and 38.5%, respectively, across all the centres reviewed. The mean numbers of operating sessions before and during the COVID-19 pandemic were 85.1±30.3 and 50.6±25.7, respectively (P=0.005). All centres gave priority to cancer-related surgeries. Benign prostatic hyperplasia-related surgery (39.1%) and ureteric stone surgery (25.5%) were the most commonly delayed surgeries. The degree of reduction in urology services was less than that during SARS (47.2%, 55.3%, and 70.5% for operating sessions, cystoscopy, and biopsy, respectively). The mean numbers of operations performed by residents before and during the COVID-19 pandemic were 75.4±48.0 and 34.9±17.2, respectively (P=0.002). CONCLUSION: A comprehensive review of urology practice during the COVID-19 pandemic revealed changes in every aspect of practice.

Prophylactic Dual Catheter Technique to Prevent Side Branch Snowplowing Complications during Angioplasty and Stenting.

OBJECTIVE: Angioplasty and Stenting of intracranial atherosclerotic lesions have a higher complication rate and a large proportion of this is attributable to side branch arterial occlusion from forceful displacement of the atheroma into the ostia or snowplowing effect. This can result in severe disabilities when it result in small infarcts involving eloquent areas in the posterior circulation or the motor tracts. MATERIALS AND METHODS: We present a series of 6 cases utilizing a new dual catheter technique for maintaining the patency of at-risk vessels during angioplasty and stenting. There are several methods previously described to help reduce the incidence of stroke but because they do not have a physical presence in the ostia to protect it, they are unable to guarantee the patency of the vessel. RESULTS: All 6 patients underwent angioplasty and stenting with the technique. The patients were assessed for complications with post-procedure magnetic resonance imaging and no complications were found. CONCLUSION: In this preliminary series, the dual catheter technique appears to safe and effective in preventing occlusion of the adjacent branch arteries. This technique may facilitate the use of the Wingspan stent in the treatment of intracranial atherosclerotic stenotic segments by reducing the risk of peri-procedural stroke.

MRI audit of complications in intracranial stenosis treated with Wingspan device.

OBJECTIVES: To evaluate the safety and efficacy of the Wingspan device for the treatment of symptomatic intracranial atherosclerotic stenosis (ICAS). METHODS: We audited a prospective ongoing database of consecutive patients who received Wingspan stenting between January 2013 and December 2015. All patients underwent MRI to audit any complications during the early follow-up period. We focused on the clinical demographics, lesion characteristics, treatment results, and periprocedural complications. Functional outcomes were measured with the modified Rankin Scale (mRS) at discharge and after 3 months. RESULTS: Intracranial stenting was performed in 50 patients (100%). Mean stenosis pre-stenting was 76.5±13.1% and post-stenting residual stenosis was 19.8±13.8%. The overall 30-day rate of procedure-related complications was 6.0% (3/50). Two patients (4%) developed in-stent restenosis, one of whom had a dissection at the middle cerebral artery. Interestingly, on the follow-up MRI scan there was a high incidence of asymptomatic diffusion-weighted imaging (DWI) hyperintensities, 46% (23/50) presumed to be due to microembolic causes. At the 90-day, 180-day, and 1-year follow-up, three patients had further strokes resulting in a total complication rate of 12%. 92% had excellent outcomes (mRS 0-1) and only one patient had deterioration of his mRS score. CONCLUSIONS: ICAS treated by Wingspan stenting using pre-placement balloon angioplasty appears safe and effective with a high technical success rate and favorable outcomes. There is a high incidence of asymptomatic DWI hyperintensites post-procedure, but these do not appear to result in long-term sequelae.

Assessment of angiographic vascularity of meningiomas with dynamic susceptibility contrast-enhanced perfusion-weighted imaging and diffusion tensor imaging.

BACKGROUND AND PURPOSE: The roles of DTI and dynamic susceptibility contrast-enhanced-PWI in predicting the angiographic vascularity of meningiomas have not been studied. We aimed to investigate if these 2 techniques could reflect the angiographic vascularity of meningiomas. MATERIALS AND METHODS: Thirty-two consecutive patients with meningiomas who had preoperative dynamic susceptibility contrast-enhanced-PWI, DTI, and conventional angiography were retrospectively included. The correlations between angiographic vascularity of meningiomas, classified with a 4-point grading scale, and the clinical or imaging variables-age and sex of patient, as well as size, CBV, fractional anisotropy, and ADC of meningiomas-were analyzed. The meningiomas were dichotomized into high-vascularity and low-vascularity groups. The differences in clinical and imaging variables between the 2 groups were compared. Receiver operating characteristic curve analysis was used to determine the diagnostic performance of these variables. RESULTS: In meningiomas, angiographic vascularity correlated positively with CBV but negatively with fractional anisotropy. High-vascularity meningiomas demonstrated significantly higher CBV but lower fractional anisotropy as compared with low-vascularity meningiomas. In differentiating between the 2 groups, the area under the curve values were 0.991 for CBV and 0.934 for fractional anisotropy on receiver operating characteristic curve analysis. CONCLUSIONS: CBV and fractional anisotropy correlate well with angiographic vascularity of meningiomas. They may differentiate between low-vascularity and high-vascularity meningiomas.

Taiwan aneurysm registry: multivariate analysis of two-month, one-year, and two-year outcomes after endovascular and microsurgical treatment of ruptured aneurysms.

We compared the outcomes of endovascular coiling with microsurgical clipping of aneurysms in a Taiwanese population. In an ambi-directional cohort design, patient baseline characteristics and clinical course after treatment for ruptured subarachnoid aneurysm were abstracted from medical records from three hospitals to examine and compare differences in post-operative outcomes between those treated with endovascular coiling and those treated with microsurgical clipping. Outcomes were measured, using the modified Rankin scale, two months, one year and two years postoperatively. Of the 642 patients enrolled in the study, 281 underwent endovascular treatment and 361 underwent neurosurgery. The demographics and baseline characteristics of two groups were comparable except for a larger maximum target aneurysm lumen size (p=0.02) in the endovascular group. Patients who underwent the endovascular procedure tended to have a better quality of life than those who had neurosurgery (p<0.01). When the severity of symptom data was pooled into two groups (Rankin values 0-2 and 3-6) a statistically significant relationship was found between the severity of symptoms and age, Hunt and Hess grade, number of target aneurysms detected, and log of maximum target aneurysm lumen size (all p≤0.01). After controlling for potential confounding factors and using the lumped Rankin outcome data, no significant difference in outcome was found between the two procedures at either time point. Our study indicated that endovascular coiling achieves results comparable to surgical clipping for patients with ruptured subarachnoid aneurysms in a Taiwanese population.

Differentiation of primary central nervous system lymphomas and glioblastomas: comparisons of diagnostic performance of dynamic susceptibility contrast-enhanced perfusion MR imaging without and with contrast-leakage correction.

BACKGROUND AND PURPOSE: Contrast leakage results in underestimation of the CBV of brain tumors. Our aim was to compare the diagnostic performance of DSC perfusion MR imaging without and with mathematic contrast-leakage correction in differentiating PCNSLs and glioblastomas. MATERIALS AND METHODS: Perfusion parameters-CBV, corrected CBV, and leakage coefficient-were measured in enhancing tumor portions and contralateral NAWM of 15 PCNSLs and 20 glioblastomas, respectively. The ratios of CBV and corrected CBV were calculated by dividing the tumor values by those obtained from contralateral NAWM. A paired t test was used to compare tumor K2 and NAWM K2, as well as tumor CBV ratios without and with leakage correction. Comparisons of CBV, corrected CBV, and K2 between PCNSLs and glioblastomas were done by using a 2-sample t test. The diagnostic performance of DSC perfusion MR imaging without and with contrast-leakage correction was assessed with receiver operating characteristic curve analysis. RESULTS: PCNSLs and glioblastomas demonstrated higher K2 than those in their contralateral NAWM. Corrected CBV ratios were significantly higher than the uncorrected ones for both tumors. PCNSLs had lower CBV ratios (P < .001), lower corrected CBV ratios (P < .001), and higher K2 (P = .001) compared with glioblastomas. In differentiating between PCNSLs and glioblastomas, the area under the curve of the CBV ratio, corrected CBV ratio, and K2 were 0.984, 0.940, and 0.788, respectively. CONCLUSIONS: PCNSL can be differentiated from glioblastoma with CBV ratios, corrected CBV ratios, and K2. CBV without contrast-leakage correction seems to have the best diagnostic performance in differentiating the 2 tumors.

Prospective comparison of angio-seal versus manual compression for hemostasis after neurointerventional procedures under systemic heparinization.

BACKGROUND AND PURPOSE: The use of arterial closure device in patients with prolonged high ACT values has not been extensively studied. The aim of this study was to compare the safety and efficacy of an arterial closure device, Angio-Seal, with manual compression in patients on anticoagulation following neurointerventional procedures. MATERIALS AND METHODS: This was a 2-center prospective study approved by our institutional review boards. In total, 153 consecutive patients with 174 arteriotomies (86 men, 67 women; mean age, 56.1 ± 16.2 years) following femoral arterial puncture for neurointerventional procedures were enrolled in convenience sampling. All of the patients were systemically heparinized with an ACT between 250 and 500 seconds before removal of the sheath after the procedure. Group 1 consisted of 104 arteriotomies that were closed with an arterial closure device (Angio-Seal), and group 2 consisted of 70 arteriotomies treated with manual compression. The ACT before sheath removal, time to hemostasis, and complications immediately and 24 hours after the procedure were recorded. RESULTS: The mean ACT before sheath removal was 284.8 ± 37.6 seconds (range, 250-414 seconds). The mean hemostasis time was significantly shorter in group 1 (2.4 ± 11.7 minutes) compared with group 2 (44.7 ± 27.4 minutes) (95% CI, 38.16-51.24 minutes; P < .001). Hematoma occurred in 9 patients in group 1 (8.6%) and 18 in group 2 (25.7%). One patient developed an arterial occlusion after hemostasis with the closure device, but this was successfully revascularized. CONCLUSIONS: Angio-Seal was found to safely and effectively achieve rapid closure of the femoral access site in patients undergoing neuroendovascular procedures under systemic heparinization with an ACT in the range of 250-500 seconds.

Contralateral de novo intraosseous arteriovenous malformation in a child with arteriovenous malformation of mandible treated by endovascular embolotherapy. A case report.

We describe our experience of the development of contralateral de novo intraosseous AVMs in a ten-year-old girl with AVMs of the mandible who underwent endovascular embolotherapy. She initially presented with intermittent oral bleeding. Computed tomography and digital subtraction angiography demonstrated intraosseous AVMs within the right mandible. The AVMs were treated by transosseous direct-puncture and transarterial embolization with Guglielmi detachable coils and n-butyl cyanoacrylate glue. However, de novo intraosseous AVMs developed within the previously healthy contralateral mandible and resulted in dangerous oral bleeding. Therefore, we suggest regular follow-up and prompt retreatment of any residual mandibular AVMs in patients undergoing endovascular or surgical treatment to prevent subsequent development of "secondary" AVMs and life-threatening oral bleeding.

Large-area anodized alumina nanopore arrays assisted by soft ultraviolet nanoimprint prepatterning.

Aluminium anodization under optimized conditions can naturally generate close-packed and aligned nanopore arrays, but the spatial extent of such regular pore arrangement is generally limited. Here we demonstrated the use of soft ultraviolet nanoimprint lithography to guide the formation of nanopores at specific locations, using an elastomer negative mold for the process. By anodizing at voltages which naturally led to the formation of pores with matching averaged interpore separation, pre-patterned triangular holes (diameter 100 nm, periodicity 350 nm) on aluminium thin films induced conformal growth of nanopores at pre-defined positions. In addition, pores in geometries other than close-packed patterns were prepared, with square pore arrangement being demonstrated in this work. The influence of the anodization voltage on the final pore formation was also studied. Our results illustrated the possibility to fabricate well-organized nanopore arrays with conditions far less stringent than those reported in literature, which has the potential to be adopted for applications where regular pore alignment are critical.

Differentiation of pyogenic brain abscesses from necrotic glioblastomas with use of susceptibility-weighted imaging.

BACKGROUND AND PURPOSE: A common imaging finding in brain abscess and necrotic glioblastoma is a T2 hypointense margin. The features of this hypointense rim on SWI have not been previously described, to our knowledge. We aimed to differentiate abscesses from glioblastomas by assessing the morphology of their lesion margin by using SWI. MATERIALS AND METHODS: T2WI and SWI were performed in 12 abscesses and 20 rim-enhancing glioblastomas. On T2WI and SWI, the prevalence and the border types (complete versus incomplete) of hypointense rims were qualitatively assessed. On SWI, the contour (smooth versus irregular) and the location of hypointense rims relative to the contrast-enhancing rims as well as the prevalence of the "dual rim sign," defined as 2 concentric rims at lesion margins with the outer one being hypointense and the inner one hyperintense relative to cavity contents, were also analyzed. RESULTS: Prevalence and the border types of the hypointense rims on T2WI were not different between abscesses and glioblastomas. On SWI, there were significantly more hypointense rims that were complete (P < .001) and smooth (P < .001), having the same location as the contrast-enhancing rims (P < .001) for abscesses. A dual rim sign was present in 9 of 12 abscesses but absent in all glioblastomas (P < .001). CONCLUSIONS: SWI may be helpful in differentiating pyogenic abscesses from necrotic glioblastomas. The dual rim sign is the most specific imaging feature distinguishing the 2.

A safe and efficacious alternative: sonographically guided internal jugular vein puncture for intracranial endovascular intervention.

Transvenous interventions for intracranial vascular lesions are usually performed via venous access of a femoral vein puncture. However, the transjugular route is an alternative with a shorter and less tortuous vascular access for intracranial lesions. Although puncture of the internal jugular vein is generally believed to be too dangerous owing to potential hazardous complications, the safety of the sonographically guided retrograde internal jugular vein puncture technique for intracranial intervention has not been fully evaluated in the English literature. We present our experience with a total of 44 transjugular intervention procedures between April 1999 and June 2010. We believe sonographically guided internal jugular vein puncture is a safe and efficacious technique for establishing transvenous access for an intracranial endovascular intervention.

Correlation between the flow pattern of the circle of Willis and segmental perfusion asymmetry after carotid artery revascularization.

BACKGROUND: To correlate cerebral perfusion and flow patterns after carotid artery revascularization within the circle of Willis (CoW). METHODS: Sixty-five patients (male/female ratio: 38/27; mean age: 63.2±8.4years; range: 44-82years) with symptomatic carotid artery stenosis underwent magnetic resonance (MR) angiography and perfusion imaging prior to and after carotid artery stenting (CAS). Regions of interest (ROIs) on the MR perfusion maps included the corona radiata (CR), centrum semiovale (CSO), occipital region (O), and basal ganglia region (BA) in both stented and non-stented hemispheres. The non-stented hemisphere was used as internal control. RESULTS: Subjects were assigned to the altered CoW group (N=31) vs. the static CoW group (N=34). Thirty-one subjects (47.6%) had an altered flow pattern in the CoW after CAS, and thirty-four (52.4%) retained a static CoW configuration. Relative cerebral blood volume (rCBV) interhemispheric index correlated with CoW morphologic alterations after carotid stenting. Altered CoW group had a higher regional interhemispheric index of rCBV in the CR (1.23±0.15 vs. 0.87±0.13; P=0.03) and basal ganglia (1.25±0.12 vs. 0.91±0.11; P=0.03) compared to the static group. CONCLUSIONS: An association between the regional cerebral blood volume (rCBV) interhemispheric asymmetry and CoW collateralization was observed. In addition, the CR, rather than CSO, was found to have topographic significance.

Embolization of a ruptured lenticulostriate artery aneurysm.

Aneurysms arising from the lenticulostriate artery (LSA) are rare. So far, only 23 cases have been reported in the literature (Ahn et al. 2007 [1], Gandhi et al. 2008 [2], Harreld et al. 2010 [3]). Early detection and treatment of these aneurysms is difficult because of their small size, deep location and complex surrounding vasculature. The majority of reported cases were treated surgically, and only two were treated with endovascular embolization (Harreld et al. 2010 [3], Larrazabal et al. 2001 [4]). We present here a case of an LSA aneurysm that was successfully embolized with n-butyl cyanoacrylate (n-BCA) with no recurrence after 1 year of follow-up.

Comparison of the risk of oculomotor nerve deficits between detachable balloons and coils in the treatment of direct carotid cavernous fistulas.

BACKGROUND AND PURPOSE: Transarterial balloon embolization used to be the preferred method for treating DCCFs; however, a strayed, overinflated, or migrated balloon may lead to oculomotor palsy. This investigation compared the use of detachable balloons and GDCs, which were previously used only in cases of balloon-technique failure and are now increasingly used as a first-line treatment for DCCFs, in terms of the risk of oculomotor nerve deficit, mortality/morbidity, and initial angiographic results. MATERIALS AND METHODS: Among 48 patients with DCCFs treated with endovascular embolization at our institution between March 2004 and May 2009, 38 patients were included in this review. Patients who underwent trapping procedures, a second intervention within 2 weeks, or any procedure that included n-BCA infusion were excluded. Twenty of the enrolled patients were treated with transarterial balloons and the other 18, with GDCs. RESULTS: Five patients (25%) in the balloon group and none in the coil group had oculomotor nerve deficits within 2 weeks. The rate of procedure-related oculomotor nerve deficit was significantly higher in the balloon group than in the coil group (P = .048). There were no significant differences in terms of procedure-related mortality/morbidity or initial angiographic results between the 2 groups. CONCLUSIONS: The risk of procedure-related oculomotor nerve deficit in the treatment of DCCFs was significantly lower when using a GDC than with a detachable balloon. GDCs may, therefore, be considered as feasible, effective, and safe for DCCFs as detachable balloons.

Differentiating Components of Cerebral Arteriovenous Malformations Using T1-Weighted Gradient Recall Echo MR Imaging.

Cerebral arteriovenous malformation (AVM) typically shows signal void on conventional MR images, making differentiation of each component difficult. We analyzed the MR signal intensity of AVM components on T1-weighted gradient recalled echo pulse sequence images. We retrospectively studied 29 patients with AVM between 2006 and 2008. Patients were excluded if they had 1) intracranial hemorrhage, 2) previous intervention for AVM. All patients underwent MR study on a 3T system (Magentom TIM Trio, Siemens). Pulse sequences included T1-weighted gradient recalled echo (T1GRE), T2-weighted (T2), time-of-flight (TOF), and contrast-enhanced T1-weighted (cT1) images. Digital subtracted angiography (DSA) was performed in all patients as a diagnostic standard. Signal intensity of each AVM component was recorded and compared between pulse sequences. Nine patients were studied (five men; mean age 39.1 years) and nine AVM were identified (mean size, 3.9 cm). Three different signal intensities (hypo-, iso-, and hyper-intensity) were observed in all nine patients on T1GRE. Only one signal intensity was seen on T2 (flow void) and cT1 images (hyperintensity) in nine patients. Two different signal intensities were observed in all seven patients with TOF images. The T1GRE image showed the largest number of different signal intensities of AVM when compared with other pulse sequences, thus providing clearer structural delineation. Routine use of the T1GRE pulse sequence can help pre-therapeutic planning or follow-up of AVM.

Differentiation between classic and atypical meningiomas with use of diffusion tensor imaging.

BACKGROUND AND PURPOSE: The differentiation between classic and atypical meningiomas may have implications in preoperative planning but may not be possible on the basis of conventional MR imaging. Our hypothesis was that classic and atypical meningiomas have different patterns of intratumoral water diffusion that will allow for differentiation between them. MATERIALS AND METHODS: Preoperative diffusion tensor imaging (DTI) was performed in 12 classic and 12 atypical meningiomas. Signal intensity of solid-enhancing tumor regions on diffusion-weighted trace images and apparent diffusion coefficient (ADC) and fractional anisotropy (FA) maps was assessed. Regions of interest (ROIs) were placed in solid-enhancing regions, peritumoral edema, and contralateral normal-appearing white matter (NAWM) to measure tensor metrics including major (lambda(1)), intermediate (lambda(2)) and minor eigenvalues (lambda(3)) and FA and ADC values. Distribution of tensor shapes within enhancing tumors was calculated for all tumors. Differences between classic and atypical meningiomas in tumor signal intensity, intratumoral and peritumoral tensor metrics, as well as tensor shapes distribution were statistically analyzed. RESULTS: A significantly greater proportion of atypical meningiomas were isointense and hypointense on ADC maps (P = .007). Classic meningiomas had significantly lower FA (P = .012), higher ADC (P = .011), greater lambda(2) (P = .020) and lambda(3) (P = .003). There was significantly more spherical diffusion in classic than in atypical meningiomas (P = .020). All diffusion tensor metrics for peritumoral edema of the 2 tumor groups did not differ. CONCLUSION: DTI showed that intratumoral microscopic water motion is less organized in classic than in atypical meningiomas. This feature may allow for noninvasive differentiation between classic and atypical meningiomas.

Primary cerebral lymphoma and glioblastoma multiforme: differences in diffusion characteristics evaluated with diffusion tensor imaging.

BACKGROUND AND PURPOSE: Differentiating between primary cerebral lymphoma and glioblastoma multiforme (GBM) based on conventional MR imaging sequences may be impossible. Our hypothesis was that there are significant differences in fractional anisotropy (FA) and apparent diffusion coefficient (ADC) between lymphoma and GBM, which will allow for differentiation between them. MATERIALS AND METHODS: Preoperative diffusion tensor imaging (DTI) was performed in 10 patients with lymphoma and 10 patients with GBM. Regions of interest were placed in only solid-enhancing tumor areas and the contralateral normal-appearing white matter (NAWM) to measure the FA and ADC values. The differences in FA and ADC between lymphoma and GBM, as well as between solid-enhancing areas of each tumor type and contralateral NAWM, were analyzed statistically. Cutoff values of FA, FA ratio, ADC, and ADC ratio for distinguishing lymphomas from GBMs were determined by receiver operating characteristic curve analysis. RESULTS: FA and ADC values of lymphoma were significantly decreased compared with NAWM. Mean FA, FA ratio, ADC (x10(-3) mm(2)/s), and ADC ratios were 0.140 +/- 0.024, 0.25 +/- 0.04, 0.630 +/- 0.155, and 0.83 +/- 0.14 for lymphoma, respectively, and 0.229 +/- 0.069, 0.40 +/- 0.12, 0.963 +/- 0.119, and 1.26 +/- 0.13 for GBM, respectively. All of the values were significantly different between lymphomas and GBM. Cutoff values to differentiate lymphomas from GBM were 0.192 for FA, 0.33 for FA ratio, 0.818 for ADC, and 1.06 for ADC ratio. CONCLUSIONS: The FA and ADC of primary cerebral lymphoma were significantly lower than those of GBM. DTI is able to differentiate lymphomas from GBM.

Cost-effective screening for urinary tract infections in urogynaecological patients.

This study aims to test the cost-effectiveness of reagent-strip urine nitrite compared with microbiological laboratory testing for screening of urinary tract infections (UTI). The study is a retrospective review of 708 female patients who underwent cystometry during a 1-year period. Urine dipstick nitrite was used as a screening test for UTI while urine cultures were taken as an outcome. Symptoms of UTI were noted. Of 708 patients screened, 70 (9.9%) had a significant UTI. Only 32 (4.5%)of 708 patients were nitrite positive. Urine dipstick nitrite has sensitivity of 40%, specificity of 99%, positive predictive value (PPV) of 88 % and negative predictive value (NPV) of 94%. If the screening test included symptoms for UTI together with urine nitrite, the results are: sensitivity 89%, specificity 31%, PPV 12% and NPV 96%. A combination of screening with urine nitrite and UTI symptoms can increase sensitivity to 89%. A total of 29% of specimens (screen negative=nitrite negative/asymptomatic) can then be excluded from UFEME/culture testing, thus resulting in cost savings.

Direct Intratumoral Pre-surgical Embolization of Orbital Hemangioblastoma. A Case Report.

Orbital hemangioblastomas of extraretinal origin are extremely rare and few cases have been reported. We describe a 48-year-old woman with progressive right visual loss and proptosis. Computed tomography showed an avidly enhanced transpatial solid mass in the right orbit with outward protrusion. The mass was presumed to be of extraretinal origin because of its unusually large size, but there was only mild involvement of the eyeball. The histopathologic characteristics of this tumor were identical to those seen in central nervous system hemangioblastomas. The hypervascularity of the lesion would have made surgical intervention difficult. Preoperative embolization was indicated and was performed by direct tumor puncture and injection of N-butyl cyanoacrylate with a satisfactory result.