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Background and Purpose: Patients with vertebral fractures containing intraosseous clefts may represent a distinct subgroup of vertebroplasty patients, yet the development of subsequent vertebral fractures in this population has not been explored. We tested the hypothesis that after vertebroplasty for intraosseous clefts, subsequent fractures would occur earlier and more frequently than after treatment of non-cleft-containing fractures., Methods: We retrospectively reviewed 362 patients treated with vertebroplasty for osteoporotic fractures. The location, frequency, and timing of subsequent fractures were compared between 2 subgroups: group 1, patients treated at fractures containing clefts, and group 2, treated patients without clefts. A vertebra-by-vertebra analysis was used to compare the relative risk and timing of subsequent fractures adjacent to vertebrae with or without clefts., Results: Group 1 included 63 patients treated at 65 vertebrae and group 2 included 250 patients treated at 399 vertebrae. Group 1 demonstrated a nearly twofold increased risk of subsequent fracture (odds ratio [OR], 1.90; 95% confidence interval [CI], 1.04-3.49, P = .037). At the vertebral level, the relative risk of subsequent fracture was 2.02 (95% CI, 1.46-2.58; P = .013) times greater adjacent to a treated cleft. Fractures adjacent to any treated level occurred significantly sooner than nonadjacent fracture (P = .0004). The presence of a cleft was not significantly associated with the timing of subsequent fractures., Conclusions: Patients with osteoporotic vertebral fractures containing clefts are at increased risk for subsequent fractures and treatment of these clefts is associated with increased rates of adjacent fracture. There is no significant difference in the timing of subsequent fractures based on the presence of a cleft.

Background and Purpose: Percutaneous vertebroplasty procedures require relatively long durations of fluoroscopic guidance, which might lead to substantial radiation dose to operators. Specialized injection devices have been proposed to limit operator exposure. Our purpose was to compare the radiation dose to the operator's hands during vertebroplasty when using 1-cc syringes versus that when using an injection device., Methods: Radiation dosimeters were worn on the left wrist during 39 vertebroplasty injection procedures in 25 patients. Cases were alternated between the use of 1-cc syringes (19 procedures) and the use of an injection device (20 procedures). For each procedure, one dosimeter was worn throughout the procedure, both during needle placement and injection, and a second dosimeter was worn during the injection phase only. Mean doses for the whole case and mean doses for the injection procedure alone were compared between groups., Results: Mean whole case dose was 128 +/- 161 mrem (range, 0-660 mrem) for the 1-cc syringe group versus 98 +/- 90 mrem (range, 0-340 mrem) for the injection device group (P =.23). Mean dose during injection was 100 +/- 145 mrem (range, 0-660 mrem) for the 1-cc syringe group versus 55 +/- 43 mrem (range, 0-130 mrem) for the injection device group (P =.09). Three of 19 1-cc syringe cases yielded zero dose, compared with four of 20 injection device cases. Duration of injection was markedly different between groups, with mean injection times of 4.2 and 7.5 min for 1-cc syringe and injection device cases, respectively (P <.00002). Mean injection dose per minute of lateral fluoroscopy was 23.6 and 7.3 mrem for the 1-cc syringe and injection device groups, respectively (P =.002)., Conclusion: The use of an injection device significantly decreased the radiation dose to the operator's extremity per unit time of injection. However, total dose per injection was equivalent between groups because of significantly longer injection duration for the injection device cohort.

Background and Purpose: Recurrent pain after vertebroplasty is relatively common, usually representing a new fracture at a different vertebral level. In a small cohort described herein, clinical and imaging findings indicated that recurrent pain arose from abnormality of the previously treated level. Our purpose was to demonstrate that repeat percutaneous vertebroplasty performed within the same fractured vertebra can offer therapeutic benefit for patients with recurrent pain after initial treatment., Methods: We conducted a retrospective review of consecutive vertebroplasty procedures performed at our institution to define a patient population that underwent repeat vertebroplasty for recurrent pain at previously treated vertebral levels. We identified six such patients over an 8-year period, and clinical outcomes were assessed through quantitative measurements of pre- and postoperative levels of pain and mobility., Results: Initial vertebroplasty resulted in substantial improvement in pain in all six patients. Patients developed recurrent pain between 8 days and 167 days after initial vertebroplasty. After repeat vertebroplasty, five of the six patients reported a reduction of at least 3 points in their rating of pain, with a mean reduction of 6.5 points and a mean postoperative pain level of 3.5 points (11-point scale). Four of six patients reported impaired mobility before repeat vertebroplasty, and all four demonstrated a postoperative improvement in mobility. Mean increase in mobility was 1.50 points, and the mean postoperative mobility impairment was 0.25 points (5-point scale)., Conclusion: The clinical outcomes of the patients within this case series suggest that repeat percutaneous vertebroplasty performed at previously treated vertebral levels for recurrent pain offer therapeutic benefit.

Background and Purpose: Thromboembolic events are a common source of complications during Guglielmi detachable coil (GDC) treatment of intracranial aneurysms. Thrombus formation at the coil-parent artery interface is not commonly reported but is an important potential source of emboli. We describe nine cases in which thrombus propagated from GDCs into the parent artery during coil therapy of cerebral aneurysms and subsequent treatment of the thrombus., Methods: A retrospective review of a procedural database was performed to identify cases in which thrombus occurred during GDC treatment of cerebral aneurysms during a 30-month period. All images were reviewed at the time of the procedure. Nine cases of thrombus forming at the coil-parent artery interface and five cases of distal emboli were identified among 210 cases. All patients underwent anticoagulation with heparin during GDC treatment procedures., Results: Thrombus was identified at the coil-parent artery interface during GDC treatment in nine (4.3%) of 210 cases. In each case, the thrombus was recognized before distal embolic complication occurred and was successfully treated with heparin alone (five patients) or with heparin plus a glycoprotein IIb-IIIa inhibitor (four patients)., Conclusion: Potential clinical complications can be avoided by early recognition of thrombus at the coil-parent artery interface and by administering appropriate medical therapy.

Background and Purpose: Vertebroplasty performed in the mid- and upper thoracic spine presents technical challenges that differ from those in the lower thoracic and lumbar region. We herein report results of percutaneous vertebroplasty for treatment of painful, osteoporotic compression fractures in the mid- and upper thoracic spine., Methods: Retrospective chart review identified vertebroplasty treatments performed for painful osteoporotic compression fractures at T4-T8. The following were catalogued: percentage of vertebral body compression, needle size, surgical approach, clinical outcome, volume of cement injected, and complications., Results: Sixty-three vertebral bodies were treated in 41 patients. Mean percentage of compression was 44%. Bipediculate injections were used in 12 (19%) of 63 treatment levels, and unipediculate injections were used in 51 (81%) of treatments (75 injections performed). Eleven-gauge needles were used for 55 (73%) of the 75 injections, and 13-gauge needles were used for 20 (27%). Clinical follow-up was available for 76% of the patients. Mean pre- and postoperative pain intensity was 9.7 +/- 1.0 and 1.7 +/- 1.9, respectively (P <.0001). Mean pre- and postoperative medication scores were 3.4 +/- 0.7 and 1.7 +/- 1.7, respectively (P =.075). Fracture involving the pedicle used for needle access was noted in one (1.3%) of 75 injections; this pedicle had been traversed using a 13-gauge needle. Staphylococcus epidermidis infection occurred in one case. No cases of pneumothorax were noted., Conclusion: Transpedicular vertebroplasty is readily and safely performed using 11-gauge needles in the mid- and upper thoracic regions, yielding excellent pain relief and low complication rates.

We report a case of iatrogenic aneurysm rupture during coil embolization in a 55-year-old woman. Surgical intervention resulted in a good clinical outcome. To our knowledge, this technique for the salvage of catheter-induced aneurysm perforation has not been previously reported.

Background and Purpose: Controversy exists regarding the utility of antecedent venography in percutaneous vertebroplasty. Our purpose was to determine whether antecedent venography improves clinical outcomes and/or decreases extravertebral cement extravasation in these procedures., Methods: We retrospective reviewed outcomes of consecutive percutaneous vertebroplasty procedures performed at our institution to define two populations, each consisting of 24 patients treated at 42 vertebral levels. Group 1 included patients who underwent antecedent venography, and group 2 included patients treated without venography. Clinical outcomes were assessed with quantitative measurements of pain and mobility. Venograms and postprocedural radiographs were interpreted to evaluate the number of vertebrae with extravertebral cement extravasation, degree of extravasation at each level, and correlation between venography and vertebroplasty., Results: Pain improved in 19 of 20 group 1 patients, compared with 21 of 22 group 2 patients; mean postoperative pain levels were 1.3 and 1.8, respectively (P =.50), on a scale of 0 (no pain) to 10 (worst pain). All 11 group 1 patients with impaired preoperative mobility reported postoperative improvement, as did all 12 group 2 patients; mean levels of postoperative impaired mobility for groups 1 and 2 were 0.35 and 0.27, respectively (P =.43). Twenty-two of 42 vertebrae treated in group 1 demonstrated extravasation, compared with 28 of 42 in group 2 (P =.266); amounts of extravasation did not differ. Among 22 levels of extravasation in group 1, venograms in 14 showed correlative extravasation., Conclusion: Antecedent venography does not significantly improve the effectiveness or safety of percutaneous vertebroplasty performed by qualified, experienced operators.

Background and Purpose: Previous investigators have described an association between polymethylmethacrylate (PMMA) use in hip arthroplasty and cardiovascular derangement. Our purpose was to evaluate the effects of PMMA injection on patient vital signs during percutaneous vertebroplasty., Methods: We retrospectively reviewed patient charts at our institution to gather blood pressure, heart rate, and arterial oxygen saturation data for the following time points: before, during, 5 minutes after, and 10 minutes after PMMA injection during percutaneous vertebroplasty. These data were obtained for 142 injections (78 patients), and preinjection vital signs were compared with vital signs during and after PMMA injection. Multivariable regression modeling was used to ascertain the effects of cardiopulmonary comorbidities on vital signs., Results: Mean arterial blood pressure and heart rate during, 5 minutes after, and 10 minutes after PMMA injection were not significantly different from their respective preprocedure values (P =.19-.92). Values for oxygen saturation during PMMA injection and 5 minutes thereafter were not significantly different from preprocedure values (P =.80 and.89, respectively). Oxygen saturation was significantly lower at 10 minutes after injection than before injection (P =.007), although the mean difference was negligible (0.6%)., Conclusion: We find no generalized association between PMMA injection during percutaneous vertebroplasty and systemic cardiovascular derangement.

Background and Purpose: The development of more effective intracranial aneurysm therapy depends on the ability to test various intravascular occlusion devices and techniques in preclinical animal models. This requires the creation of experimental aneurysms, which, ideally, should mimic the size and geometric features of human intracranial aneurysms. The purpose of this study was to characterize the morphologic features of elastase-induced saccular aneurysms in rabbits to determine whether the morphology of such aneurysms mimics that of human intracranial aneurysms., Methods: Elastase-induced saccular aneurysms were created in 40 New Zealand white rabbits. Intravenous digital subtraction angiography was performed 14 days after surgery. Relative to an external sizing device, the following dimensions were determined: aneurysm dome (height and width), aneurysm neck diameter, and parent artery diameter. Based on maximal diameter, aneurysms were categorized as small (2.0-4.9 mm), medium-sized (5.0-9.9 mm), or large (10-16 mm), and as narrow-necked (<4.0 mm neck width) or wide-necked (>4.0 mm neck width). Mean dome-neck ratio was calculated and compared with that of human aneurysms., Results: All aneurysm cavities were angiographically patent. Widths of the cavities ranged from 2.5 to 7.1 mm (mean, 4.1 +/- 1.2 mm); heights ranged from 3.0 to 15.6 mm (mean, 8.8 +/- 2.6 mm). Three (7.5%) of 40 aneurysms were small, 20 (50%) were medium-sized, and 17 (42.5%) were large. Twenty-two (55%) of 40 aneurysms were small-necked, and 18 (45%) were wide-necked. Mean dome-neck ratio was 1.13 +/- 0.54. Mean parent artery diameter was 4.3 +/- 1.4 mm., Conclusion: Saccular aneurysms of sizes similar to that of human intracranial aneurysms were reliably created using a simple method of vessel ligation and elastase injury. Neck sizes varied with both large and small-necked aneurysms created.

Background and Purpose: The patient populations that are most likely to benefit from percutaneous vertebroplasty (PVP) are uncertain. Our purpose was to evaluate the effect of the age of vertebral compression fracture (VCF) on clinical improvement after PVP., Methods: We performed a retrospective review of charts of patients who had undergone PVP for painful osteoporotic VCFs at our institution. The preprocedural and postprocedural outcome measurements of pain, mobility, and analgesic use were compared for 80 treatment sessions in 75 patients (122 total vertebrae treated). We assessed the association between the duration of pain before PVP and postprocedural outcomes by using multivariable analysis., Results: Age of fracture at time of PVP was not independently associated with postprocedural pain or activity. Increasing age of fracture was independently associated with slightly greater postprocedural analgesic requirement, at least for patients who required narcotics at baseline before PVP. Greater preprocedural analgesic requirement was independently associated with greater postprocedural analgesic requirement. Reduced preprocedural mobility was independently associated with reduced postprocedural mobility., Conclusion: PVP is a highly efficacious therapy for relief of pain and improvement in mobility, regardless of fracture age. PVP also is efficacious in reducing analgesic requirement, although this effect may be slightly blunted in patients who require narcotics before the procedure and in those who have older fractures.

Background and Purpose: Among the several reports of elastase-induced aneurysm models, only the rabbit common carotid artery (CCA) model has been used for testing endovascular occlusion devices. Our purpose was to study the growth characteristics of an elastase-induced aneurysm model in rabbits for the purpose of determining whether delayed aneurysm enlargement occurs after creation., Methods: Nine New Zealand White rabbits (3-4 kg) were used in this study. All study animals underwent surgery to isolate the right CCA. In three control animals, the lumen was incubated with saline and iodinated contrast material for 20 minutes. In six test animals, the lumen of the CCA was incubated with porcine elastase for 20 minutes. In all study animals, the distal right CCA was ligated. IV digital subtraction angiography was performed on postprocedural days 3, 5, 7, 14, 28, 35, 56, 84, and 112. Using an external sizing reference, the width and height of patent arterial segments at the right CCA origin were measured by two observers. For test animals, aneurysm dimensions were compared between early and late time points by using the Student's t test., Results: In the control (no elastase) animals, slitlike cavities at the origin of the right CCA decreased in size over time to become nearly obliterated by 21 days. Conversely, a short segment of the proximal CCA remained widely patent in all six test animals. With the exception of a single time point in one test animal, all "aneurysm" cavities in the test animals were dilated as compared with the normal diameter of the CCA. On day 3 after surgery, the mean width and height of the aneurysm cavities in the test animals were 3.2 +/- 0.6 and 6.0 +/- 1.3 mm, respectively. Compared with dimensions at day 3, aneurysms in test animals were larger at day 14, with mean width and height of 4.1 +/- 1.7 and 8.3 +/- 1.9 mm, respectively (P =.02). Aneurysms in test animals had increased further at 21 days compared with 14 days (P =.01). Compared with measurements obtained at 21 days, dimensions remained essentially unchanged at 28 and 35 days. Thirty-five days after surgery, mean width and height were 5.0 +/- 0.9 and 10.0 +/- 2.2 mm, respectively. Follow-up imaging performed < or = 4 months after aneurysm creation showed no further change in aneurysm dimensions., Conclusion: Elastase incubation and vessel ligation results in patent aneurysmally dilated arterial segments at the origin of the right CCA in rabbits. These aneurysms show progressive increases in diameter over time, finally stabilizing at approximately 1 month. Our data, which show early progressive aneurysm enlargement, suggest that this model may be used for the study of systemic therapies aimed at diminishing aneurysm rest regrowth and also indicate that embolization of these model aneurysms should be delayed at least 21 days after aneurysm creation.

Background and Purpose: Patient selection for percutaneous vertebroplasty is often complicated by the presence of multiple fractures or non-localizing pain. Our purpose was to determine whether increased activity revealed by bone scan imaging is predictive of a positive clinical response to percutaneous vertebroplasty., Methods: A retrospective chart review conducted at our institution yielded 28 vertebroplasty treatment sessions that had been performed after obtaining bone scan imaging for painful, osteoporotic compression fractures in 27 patients. Thirty-five compression fractures were treated during these 28 treatment sessions. In all cases, increased activity was revealed by bone scan imaging before treatment with vertebroplasty. Positive outcome was defined as subjective decrease in pain severity and/or increased level of patient mobility., Results: Subjective pain relief was noted in 26 (93%) of 28 treatment sessions. In 14 (100%) of 14 cases with quantifiable pain levels, pain improved at least 3 points on a 10-point scale (range of improvement, 3-10 points; mean improvement, 7.4 points). Among the remaining 14 treatment sessions in which patients were unable or unwilling to quantify pain severity, the pain relief was described as complete or excellent pain relief in 11 (78%) of 14 cases. In 14 (100%) of 14 cases for which semiquantitative assessment of mobility was available, mobility improved at least one level (5-point graded scale; range of improvement, 1-4 points; mean improvement, 1.7 points)., Conclusions: Increased activity revealed by bone scan imaging is highly predictive of positive clinical response to percutaneous vertebroplasty.

The authors report the clinical symptoms and response to therapy of a series of patients who presented with subacute or chronic back pain due to vertebral osteonecrosis (Kummell's spondylitis) and who underwent percutaneous vertebroplasty. The authors performed a retrospective chart review of a series of 95 patients in whom 149 painful, nonneoplastic compression fractures were demonstrated and who were treated with percutaneous transpediculate polymethylmethacrylate (PMMA) vertebroplasty. In six of these patients there was evidence of vertebral osteonecrosis, as evidenced by the presence of an intravertebral vacuum cleft on radiography or by intravertebral fluid on magnetic resonance (MR) imaging. Clinical and radiological findings on presentation were noted. Technical aspects of the vertebroplasty technique were compiled. Response to therapy, defined as qualitative change in pain severity and change in level of activity, was noted immediately following the procedure and at various periods on follow-up reviews. One man and five women, who ranged in age from 72 to 90 years (mean 81 years), were treated. Each patient had one compression fracture. The fractures were at T-11 (one patient), L-1 (two patients), L-3 (two patients), and L-4 (one patient). The pain pattern was described as severe and localized to the affected vertebra, and sometimes radiated along either flank. Pain duration ranged from 2 to 12 weeks, and the pain was refractory to conservative therapy that consisted of bedrest, analgesics, and external bracing. At the time of treatment, all patients were bedridden because of severe back pain. In all patients either plain radiographic or computerized tomography evidence of intravertebral vacuum cleft or MR imaging evidence of vertebral fluid collection consistent with avascular necrosis of the vertebral body was demonstrated. Four patients underwent bilateral transpediculate vertebroplasty, and two patients underwent unilateral transpediculate vertebroplasty. The fracture cavities were specifically targeted for PMMA injection. Additional fortification of the osteoporotic vertebral body trabeculae was also performed when feasible. "Cavitygrams" or intraosseous venograms with gentle contrast injection were obtained prior to application of cement mixture. In all patients subjective improvement in pain and increased mobility were demonstrated posttreatment. The follow-up period ranged from 4 to 24 hours after treatment. Two patients made additional office visits at 1 and 3 months, respectively. Patients presenting with vertebral osteonecrosis (Kummell's spondylitis) often suffer from local paraspinous or referred pain. When performing vertebroplasty on these patients, confirmation of entry into the fracture cavities with contrast-enhanced "cavitygrams" should be performed prior to injection of PMMA cement. The response to vertebroplasty with regard to amelioration of pain and improved mobility is encouraging.

Background and Purpose: Abstract presentations are a valuable means of rapidly conveying new information; however, abstracts that fail to eventually become published are of little use to the general medical community. Our goals were to determine the publication rate of neuroradiologic papers originally presented at national meetings in 1993 and to assess publication rate as a function of neuroradiologic subspecialty and study design., Methods: Proceedings from the 1993 ASNR and RSNA meetings were reviewed. A MEDLINE search encompassing 1993-1997 was performed cross-referencing lead author and at least one text word based on the abstract title. All ASNR and RSNA neuroradiologic abstracts were included. Study type, subspecialty classification, and sample size were tabulated. Publication rate, based on study design and neuroradiologic subspecialty, was compared with overall publication rate. Median duration from meeting presentation to publication was calculated, and the journals of publication were noted., Results: Thirty-seven percent of ASNR abstracts and 33% of RSNA neuroradiologic abstracts were published as articles in indexed medical journals. Publication rates among neuroradiologic subspecialty types were not significantly different. Prospective studies presented at the ASNR were published at a higher rate than were retrospective studies. There was no difference between the publication rate of experimental versus clinical studies. Neuroradiologic abstracts were published less frequently than were abstracts within other medical specialties. Median time between abstract presentation and publication was 15 months., Conclusion: Approximately one third of neuroradiologic abstracts presented at national meetings in 1993 were published in indexed journals. This rate is lower than that of abstracts from medical specialties other than radiology.