Atypical teratoid/rhabdoid tumors in adult patients: CT and MR imaging features

Primary AT/RT is a rare highly malignant tumor of the CNS, usually occurring in children younger than 5 years of age. The objective of this study was to characterize the CT and MR imaging findings in a series of 5 adult patients with pathologically proved AT/RT. All 5 AT/RTs were supratentorial. In 2 patients who underwent nonenhanced CT, the tumors appeared isoattenuated, and 1 of the 2 tumors contained calcifications. Solid portions of the tumors on MR imaging were isointense on T1-weighted, T2-weighted, and FLAIR images, and 1 case showed restricted diffusion on DWI. The tumors also demonstrated a bandlike rim of strong enhancement surrounding a central cystic area on contrast-enhanced T1-weighted imaging. One tumor was associated with destruction of the calvaria. Although AT/RTs can have nonspecific findings, the tumors in our series were large and isointense on T1-weighted, T2-weighted, and FLAIR images with central necrosis and prominent rim enhancement.

Results of endovascular management for mid-basilar artery aneurysms

We evaluated the results of endovascular management of patients with mid-basilar artery aneurysm (mBAA). During a seven year period, 14 patients (mean age 39.6 years, male/female ratio 1:1) with mBAA were treated with endovascular techniques at our institute. Pretreatment clinical grades were determined using the Hunt-Hess scale. Outcome was evaluated using the Glasgow Outcome Scale scores (GOS) during a mean follow-up period of 15.6 months (range, three to 70 months). Fourteen patients with 15 mBAAs were treated endovascularly. Four (28.6%) patients died of rebleeding within one day after embolization. In ten mBAAs, immediate postprocedural angiograms showed that complete occlusion was achieved, subtotal occlusion in one, and incomplete occlusion in four. Follow-up angiographic results in ten patients confirmed complete occlusion of 11 aneurysms. Long-term outcome was good (GOS Score 4 or 5) in ten patients (71.4%) and fatal (GOS Score 1) in four (28.6%). Favorable overall long-term outcome can be achieved in 78.6% patients with mBAAs. Endovascular management of mBAAs is an effective treatment in the long-term. In our experience, the natural history of mBAAs is dismal.

Endovascular treatment for complex intracranial aneurysms: lessons learnt in five patients

We describe our experience in five cases of endovascular treatment for complex intracranial aneurysms. The senior author (ZW) has clinical experience with more than 6000 cases of brain aneurysms treated with endovascular techniques. Multiple endovascular therapies, such as treatment with Onyx, parent vessel occlusion, stent-assisted coiling, covered stent, can be used in an attempt to provide a solution to various clinical dilemmas associated with the management of these difficult lesions. Here, we focus on the latest five patients and lessons learnt in endovascular techniques for complex intracranial aneurysms.On the basis of the knowledge obtained over the years, multimodality endovascular techniques should be re-evaluated to improve patient outcomes.

Transarterial and transvenous embolization for cavernous sinus dural arteriovenous fistulae

We report on the safety and efficacy of trans-arterial and transvenous Onyx embolization in the treatment of dural arteriovenous fistulae (DAVFs) of the cavernous sinus. We reviewed the findings from a retrospectively database for 22 patients with cavernous sinus DAVFs who were treated with either transarterial Onyx embolization alone (n = 8) or transarterial and transvenous Onyx embolization (n = 14) over a four year period. The mean follow-up period after endovascular treatment was 21.6 months (range 3-42 mths). Total number of embolizations was 27 for 22 patients. Two patients were treated transvenously after transarterial embolization. All 22 patients (100%) experienced improvement of their clinical symptoms. All 22 patients (100%) experienced total obliteration of their DAVFs, as documented by angiography performed at a mean follow-up of 5.8 months after the last treatment. No patient experienced a recurrence of symptoms after angiography showed DAVF obliteration. One patient exhibited temporary deterioration of ocular symptoms secondary to venous hypertension after near total obliteration; one had transient V cranial nerve deficit related to transarterial embolization, and two patients exhibited transient III and VI cranial nerve weakness related to transvenous embolization. Two patients experienced recurrent symptoms after incomplete transarterial embolization and underwent transvenous embolization at three and four months. Both patients achieved clinical and angiographic cures. Transarterial and transvenous embolization with Onyx, whenever possible, proved to be a safe and effective management for patients with cavernous sinus DAVFs.

Clinical outcomes of ruptured and unruptured vertebral artery-posterior inferior cerebellar artery complex dissecting aneurysms after endovascular embolization

BACKGROUND AND PURPOSE

Surgical treatment of VA-PICA dissecting aneurysms is difficult and complication of LCNP is common. These lesions can be approached easily with endovascular technique, but complete obliteration can only be achieved in a small number of cases. Our aim was to report the clinical outcomes of VA-PICA dissecting aneurysms treated by endovascular embolization.

MATERIALS AND METHODS

Between 2001 and 2007, the authors treated 22 consecutive patients (15 men and 7 women; ranging in age from 12 to 59 years; mean age, 43 years) with VA-PICA dissecting aneurysms. Diagnosis of VA-PICA dissecting aneurysm was based on clinical, MR imaging, and cerebral angiography studies.

RESULTS

Of the 22 patients, 6 had unruptured aneurysms. One patient presented with headaches, whereas the remaining 5 patients showed brain stem ischemia. Four were treated with stent-only or stent-coil embolization, and 2 were treated with unilateral VA occlusion. Among 16 patients presenting with SAH, 10 were treated with stent-only or stent-coil embolization. The other 6 patients with SAH were treated by using unilateral endovascular VA occlusion. One patient could not return to his previous daily activities.

CONCLUSIONS

VA-PICA aneurysms are rare lesions associated with significant morbidity, and endovascular treatment strategies for these lesions were stent deployment with or without coil embolization and VA occlusion. Favorable clinical outcomes can be achieved with endovascular techniques.

Endovascular embolization for deep Basal Ganglia arteriovenous malformations

We report our experience with basal ganglia AVM embolization and clinical outcomes after embolization. We retrospectively evaluated consecutive 15 patients with AVMs in the basal ganglia with respect to the endovascular treatment of these lesions. Treatment consisted of embolization and radiosurgery in combination. The angiographic follow-up after the last management was 24-36 months (mean 27 months). Clinical follow-up monitoring (range, 24-120 months, mean 76 months) was measured by the Modified Rankin Scale (mRS). The 15 patients studied had a mean age of 25.1 years at diagnosis, and 33.3% were male. Intracranial hemorrhage (ICH) was the event leading to clinical detection in eight patients (53.3%), and 85.5% of these patients were left with hemiparesis. At presentation, eight (53.3%) patients bled a total of 11 times. Twenty-four embolization procedures (16 pedicles embolized) were performed in 15 patients with embolization as the adjunct to radiosurgery. There were three clinically significant complications. Excellent or good outcomes (mRS≤2) were observed in 13 (86.7%) patients. Unfavorable outcomes (mRS≤2) were 13.3% at follow-up, without mortality. Seven (46.7%) patients had complete AVM obliteration at follow-up. The risk of incurring a neurological deficit with basal ganglia AVM is high. Treatment of these patients is endovascular embolization with a combination of radiosurgery to prevent neurological injury from a spontaneous ICH.

Endovascular treatment accounts for a change in brain arteriovenous malformation natural history risk

This study estimated the risk and rates of intracranial hemorrhage (ICH) in patients harbor-ing brain arteriovenous malformation (BAVM) after endovascular embolization. One hundred and forty-four consecutive patients with BAVM treated with endovascular embolization between 1998 and 2003 were retrospectively reviewed. The risk of ICH subsequent to endovascular embolization was studied using Kaplan-Meier curves. We reviewed 144 patients with BAVM treated with endovascular embolization. Two hundred and sixty-nine procedures were performed, 69 were performed with silk sutures, 18 with coils, 137 with NBCA and 36 with Onyx18. Twenty-three (16.0%) patients were treated with additional gamma-knife radiosurgery and one (0.7%) with additional surgical AVM excision. Complete obliteration of BAVMs was achieved in 20 patients (13.9%). During a mean follow-up of 5.9 years for the ICH group and 6.9 years for the non-ICH group, hemorrhages occurred in 11 (17.7%) of the ICH patients and in nine (11%) of the non-ICH group (p>0.1). The annual risk of hemorrhage was 3.0% and 1.6%, respectively. In the multivariate regression model, the adjusted relative risk (RR) for hemorrhage at initial presentation was 1.6 (95% CI 1.2-3.2; p>0.1). Deep venous drainage, male sex, age or AVM size were not significantly associated with subsequent hemorrhage. ICH and non-ICH groups did not differ in progression to subsequent ICH after endovascular embolization (log-rank X (2) =1.339, p>0.1) in survival analyses. The overall annual hemorrhage risk for all patients after endovascular embolization was 2.1%. Endovascular embolization alone or combined with gamma-knife radiosurgery or surgical treatment are able to decrease ICH occurrence compared to abstention.

The incidence of trigeminocardiac reflex in endovascular treatment of dural arteriovenous fistula with onyx

This paper reports the incidence of tri-geminocardiac reflex (TCR) in endovascular treatment of dural arteriovenous fistulas (DAVFs) with Onyx. The consecutive case histories of 45 patients with DAVFs, treated with Onyx transarterially and transvenously, from February 2005 to February 2008 at Beijing Tiantan Hospital, China, were retrospectively reviewed. The time period was limited as the anesthetic and intravascular procedure was performed under the same standardized anesthetic protocol and by the same team. The TCR rate was subsequently calculated. Of the 45 patients, five showed evidence of TCR during transarterial Onyx injection and transvenous DMSO injection. Their HR fell 50% during intravascular procedures compared with levels immediately before the stimulus. However, blood pressure values were stable in all cases. The TCR rate for all patients was 11.1% (95% CI, 4 to 24%), 7.7% (95% CI, 2 to 21%) in patients treated intraarterially and 33.3% (4 to 78%) in patients treated intravenously. Once HR has fallen, intravenous atropine is indicated to block the depressor response and prevention further TCR episodes. TCR may occur due to chemical stimulus of DMSO and Onyx cast formation under a standardized anesthetic protocol and should be blunted by atropine.

Brain arteriovenous malformations and endovascular treatment: effect on seizures

We report our experience in treating patients with seizures associated with brain arteriovenous malformations (AVM) without a clinical history of intracranial hemorrhage. Between 2001 and 2003, the neurovascular unit at Beijing Tiantan Hospital treated 109 patients with brain AVM endovascularly. Thirty patients (27.5%) experienced seizures before treatment. We studied the following factors: sex, age, AVM size, AVM location, seizure type, duration of seizure history, endovascular treatment and AVM obliteration. Clinical follow-up was via telephone interview. Thirty patients with seizure disorders due to brain AVMs were endovascularly treated. The age of the patients ranged from eight to 55 years. There were 22 males and eight females. The AVMs were smaller than 3 cm in five patients, between 3 cm and 6 cm in 22, and larger than 6 cm in three. The most frequent location of the AVMs was in the frontal, followed by the parietal, temporal and occipital lobes. Sixty-seven embolization procedures were performed and total obliteration was achieved in four patients. Two patients developed a hemiparesis and three suffered temporary dysphasia after embolization. Two patients had visual field deficits. There were no deaths. The results of post-embolization seizure control during the average follow-up period of 80 months were excellent in 21 patients, good in four, fair in two and poor in three. Successful seizure control can be obtained with endovascular embolization.

Balloon kyphoplasty for acute osteoporotic compression fractures

We reviewed the effectiveness of balloon kyphoplasty in the treatment of acute symptomatic vertebral compression fractures. We assessed radiographic and functional outcome in 11 patients with a 24.3 month follow-up from a retrospectively monitored series of 11 patients who underwent balloon kyphoplasty (BKP). A visual analogue scale (VAS) and the short McGill questionnaire (MPQ) were used to assess average symptoms. Eleven patients with 19 treated vertebrae completed the study. The VAS showed significant improvement after treatment: the initial score was 9.1+/-0.6 (mean+/-SD), falling to 2.7+/-1.07 by 24.3 months (P<0.001). The MPQ also showed a significant improvement (P<0.001) at follow-up. A new fracture was seen in one patient affecting two vertebrae adjacent to the treated level. On CT following the procedure, there was cement leakage in the disc in 9% of cases. BKP is a minimally invasive procedure that has been shown to be effective in the treatment of acute symptomatic vertebral compression fractures. It appears that BKP is associated with a low incidence of procedure-related complications and cement extravasation.

Effect of curcumin on the proliferation and apoptosis of hepatic stellate cells

This study was designed to investigate the effect of curcumin (diferuloylmethane) on the proliferation and apoptosis of hepatic stellate cells (HSC). The cell line HSC-T6 (1.25 x 10(5) cells/mL) was incubated with curcumin and HSC proliferation was detected by a methyl thiazolyl tetrazolium colorimetric assay. HSC apoptosis was detected by flow cytometry, transmission electron microscope and agarose gel electrophoresis. HSC proliferation was significantly inhibited in a concentration-dependent manner (10.6 to 63.5%) after incubation with 20-100 microM curcumin, compared with a control group. At 20, 40, and 60 microM, after 24 h of incubation, curcumin was associated with a significant increase in the number of HSC in the G2/M phase, and a significant decrease in cell numbers in the S phase (P < 0.05). At these concentrations, curcumin was also associated with an increase in the apoptosis index of 15.3 +/- 1.9, 26.7 +/- 2.8, and 37.6 +/- 4.4%, respectively, compared to control (1.9 +/- 0.6%, P < 0.01). At 40 microM, the curcumin-induced apoptosis index at 12, 24, 36, and 48 h of incubation was 12.0 +/- 2.4, 26.7 +/- 3.5, 33.8 +/- 1.8, and 49.3 +/- 1.6%, respectively (P < 0.01). In conclusion, curcumin inhibits the in vitro proliferation of HSCs in the G2/M phase of the cell cycle and also induces apoptosis in a concentration- and time-dependent manner. The in vivo effect of curcumin on HSCs requires further investigation.

Intraarterial and intravenous treatment of transverse/sigmoid sinus dural arteriovenous fistulas

SUMMARY

Transverse/sigmoid sinus (TS) is the most common location for cerebral dural arteriovenous fistulas (DAVFs). Most of them are cured by venous embolization or a combination of arterial embolization and surgery/radiosurgery. Our goal was to reconsider the endovascular treatment strategy of TSDAVFs according to the new possibilities of arterial embolization using Onyx-18. Nineteen patients with TSDAVFs were included in a prospective study between 2004 and 2007. Three of them had type I, four had type IIa, six had type IIa+b, three had type III, and three had type IV fistulas. Three presented with subarachnoid hemorrhage. The approach routes, angiographic results, complications, and clinical outcome were assessed. The mean clinical follow-up period was 32.5 months. In one patient, the DAVF had been obliterated spontaneously at ten month follow-up. Complete angiographic cure was obtained in nine cases with one case of progressive thrombosis. Of these ten cures were achieved after a single procedure in seven out of ten patients who had not been embolized previously. Three patients were cured with sinus packing with prior arterial embolization. Among these 19 patients, 15 underwent follow-up angiography which confirmed the complete cure. Partial occlusion was obtained in nine patients, one was cured after additional surgery, and one underwent radiosurgery. Hallucination occurred in one completely cured patient on day one. Based on this experience, we believe that intraarterial Onyx may be the primary treatment of choice for patients with TSDAVFs. The applicability of this new embolic agent indicates the need for reconsideration of the treatment strategy for such fistulas.

Endovascular management for p2 aneurysms of the posterior cerebral artery. Experience on proximal occlusion of the p2 segmen

This study evaluated the outcomes of endovascular management for P2-segment aneurysms. From 2003 to 2008, 14 consecutive patients with P2 aneurysms were treated endovascularly by proximal P2 segment occlusion at our institution. The aneurysms included 12 P2a and two P2p aneurysms. Presenting symptoms were caused by subarachnoid hemorrhage (SAH) in six patients, stroke in five, and isolated headaches in three. Mean follow-up was 14 months. Twelve aneurysms were treated with proximal P2 segment occlusion without parent artery revascularization. Twelve aneurysms were at the P2a and two aneurysms at the P2p. Two patients developed hemianopsia after the procedure and one recovered completely within six months follow-up with one still persistent at 22-month follow-up. Proximal parent vessel occlusion was a relatively safe, effective treatment for P2 aneurysms that posed low risk for early or delayed ischemia or infarction.

Onyx migration in the endovascular management of intracranial dural arteriovenous fistulas

Onyx migration in the endovascular treatment of dural arteriovenous fistulas (dural AVFs) is uncommon. We describe five cases of Onyx migration to the heart and draining vein and its avoidance. Between February 2007 and August 2008, Onyx migration was encountered in five patients with dural AVFs treated endovascularly at our institute. Procedures performed under general anesthesia consisted of two arterial approaches and three venous approaches. Two patients with dural AVFs involving the transverse-sigmoid sinus were treated by transarterial embolization using Onyx-18 via the occipital artery and the posterior branch of the middle meningeal artery, respectively. A piece of Onyx was found in the right ventricle on post-embolization chest X-ray film in both patients, one developed tricuspid valve dysfunction requiring thoracic surgery and one was asymptomatic. The other three patients were treated with a combination of Onyx (34 or 18) and coils transvenously with venous Onyx migration leading to draining vein occlusion, one with dural AVF involving the tentorium died from venous rupture, two patients with bilateral dural AVFs of the cavernous sinus (one with deterioration of ocular symptoms and one without symptoms). Postoperative digital subtraction angiography confirmed the elimination of dural AVF in one patient, and residual fistulae in three patients. The follow-up study ranging from two to nine months (average, 4.5 months). Three patients recovered to their full activities, while one had visual disturbance. Although Onyx has been considered a controllable embolic agent, its migration to other locations causing clinical deterioration can occur. This problem should be noted and prevented.

Treatment of giant intracranial aneurysms

We report on report the clinical outcome obtained in treatment of giant intracranial aneurysms (GAs). Between 2005 and 2007, 51 patients with 51 GAs presented at our hospital. Twentynine were treated with primary parent vessel occlusion without distal bypass and ten underwent treatment preserving the parent artery. Twelve patients could not be treated endovascularly. Selective embolization (including two remodeling techniques and two stent-coil mbolizations) resulted in only one cure. Two patients died as a result of subarachnoid hemorrhage periprocedurely. Twenty-nine patients treated primarily with parent vessel occlusion and three patients treated with covered stent were considered cured after their treatments. Only one patient treated with parent vessel occlusion experienced ischemia during follow-up, which resulted in a mild neurological deficit. Of the twelve patients who could not be treated endovascularly, one succumbed to surgery, four died while being treated conservatively, and three were lost to follow-up. Parent artery occlusion, covered stent and coil occlusion provide effective protection against bleeding. In treatment of paraclinoid GAs of the internal carotid rtery, the use of a stent, and stent-assisted coil embolization may be a pitfall.

A promising adjuvant to detachable coils for cavernous packing: onyx

Transvenous embolization of cavernous dural arteriovenous fistulae (CDAVFs) with Onyx has recently been reported. This study was undertaken to assess the value of Onyx in transvenous treatment of CDAVFs. We retrospectively reviewed 18 patients who underwent transvenous embolization for CDAVFs of Barrow Type D with detachable coils and Onyx at our institution over five years. Patients were divided into two groups: group A, patients who had been treated with detachable coils; group B, patients who had been treated with a combination of detachable coils and Onyx. The approach routes, angiographic results, complications and clinical outcome were assessed for both groups. Eighteen patients with CDAVFs of Barrow Type D were treated: nine women and nine men; mean age was 41.9 years. Eleven patients treated by 19 procedures of transvenous coiling belonged to group A. Seven patients treated by eight procedures of transvenous Onyx injection belonged to group B. The periprocedural complication rate associated with coiling for both groups was 18.2% vs 16.7% with Onyx. The duration of the procedure in both groups was 6.77-/+2.49 hours vs 3.75-/+1.63 hours with coiling vs Onyx, and the cost of Onyx was cheaper than coils. An excellent outcome was achieved in both groups: 90.9% vs 100% (group A vs group B). Our results associated with both modalities of CDAVFs treatment with clinical outcome show that transvenous embolization with Onyx is a safe alternative to detachable coils in the treatment of CDAVFs. However, more cases need to be evaluated.

Clinical outcomes of basilar artery aneurysms

To evaluate the effects of endovascular treatments, we retrospectively analyzed a consecutive series of patients with basilar artery aneurysms (BAAs) treated endovascularly. During a seven year period, 43 patients (mean age 42.2 years, male/female ratio 21:22) with BAAs were treated mainly with endovascular techniques at Beijing Tiantan Hospital. Pretreatment clinical grades were determined using the Hunt-Hess scale. Outcome was evaluated using the Glasgow Outcome Scale scores (GOS) during a mean follow-up period of 21.1 months (range, 1 to 72 months). Forty-three patients had 44 BAAs, one MCA aneurysm and one P1 aneurysm. Endovascular treatment was technically feasible in 40 patients. One aneurysm thrombosed spontaneously after initial angiography. Four (9.3%) patients died periprocedurally. Immediate postprocedural angiograms in 44 BAAs showed that complete occlusion was achieved in 33 BAAs, subtotal occlusion in one and incomplete occlusion in seven. Follow-up angiographic results in 30 patients confirmed complete occlusion of 27 aneurysms, subtotal occlusion in one, and incomplete occlusion in two. Two patients with vertebrobasilar atheromatous fusiform aneurysms were treated with antiplatelet medications. Long-term outcome was good (GOS Score 4 or 5) in 39 patients (90.7%) and fatal (GOS Score 1) in four (9.3%). Favorable overall long-term outcome can be achieved in patients with BA apex aneurysms, and in 78.6% of those with BA trunk aneurysms when using endovascular techniques. Endovascular coil embolization of BAAs is an effective treatment in the long-term. Patients with vertebrobasilar atheromatous fusiform aneurysms can be treated with antiplatelet medications.

Endovascular treatment of brain arteriovenous fistulas

BACKGROUND AND PURPOSE

Brain arteriovenous fistulas (BAVFs) are dangerous lesions with significant risks for hemorrhage and re-hemorrhage; thus, the management of BAVFs is an important subject. Flow disconnection can be accomplished by surgical or endovascular techniques. We reviewed the experience in our endovascular treatment of patients with BAVFs.

MATERIALS AND METHODS

From March 2006 to March 2008, a total of 9 consecutive patients with nontraumatic BAVFs were treated at Beijing Tiantan Hospital. Dural arteriovenous fistulas and Galen aneurysmal malformations were excluded from this study. We retrospectively reviewed the medical records, cerebral angiograms, and endovascular reports for each patient. Radiographic outcome was assessed by posttreatment angiography. Clinical outcome was assessed for every patient.

RESULTS

There were 9 patients with a total of 11 BAVFs. The mean age at presentation was 17.8 years. The clinical presentations were intracranial hemorrhage in 4 patients, headaches in 2 patients, and seizure in 1 patient, with 2 patients diagnosed incidentally. All lesions were supratentorial, and a venous varix was found on angiographic examination. Seven patients were treated with coils, 1 with Onyx-34, and 1 with a combination of coils and glue. All 9 lesions were completely obliterated as demonstrated on follow-up angiographic examination. With a mean follow-up of 5.7 months (range, 3-12 months), all patients were neurologically excellent with no symptoms (modified Rankin Scale, 0).

CONCLUSIONS

BAVFs are more frequent in younger patients and frequently lead to intracranial hemorrhage. Staged endovascular coil embolization of BAVFs may be a good appropriate treatment technique.

Dissecting aneurysm at the proximal anterior cerebral artery treated by parent artery occlusion

Aneurysms of the A1 segment of the anterior cerebral artery (ACA) are rare. We described the first documented endovascular treatment of an A1 portion dissecting aneurysm by parent artery occlusion. A 43-year-old man patient presented with subarachnoid hemorrhage. Cerebral angiography demonstrated a dissecting aneurysm of the left anterior cerebral artery (ACA) at A1 portion. Because of the dissecting nature of the A1 portion aneurysm, a 2.5x15-mm Neuroform stent was placed in the left A1 portion. However, regrowth of the aneurysm was found on the three month follow-up angiogram, so the aneurysm and the left A1 portion of ACA were occluded completely.

Vertebral dissecting aneurysm treated with wingspan stent deployment and detachable coils. A technical note

We describe the first documented endovascular treatment of vertebral dissecting aneurysm using a Wingspan stent and detachable coils. A 54-year-old man presented with a nonruptured vertebral dissecting aneurysm. Because of the dissecting nature of the vertebral aneurysms, a 3x15-mm Wingspan stent was placed in the left vertebral artery. One month later, several detachable coils were introduced into the aneurysm. Six-month follow-up angiogram confirmed the obliteration. Vertebral dissecting aneurysm can be treated with Wingspan stent placement and detachable coils.

Complications related to percutaneous transarterial embolization of intracranial dural arteriovenous fistulas in 40 patients

BACKGROUND AND PURPOSE

An increasing number of intracranial dural arteriovenous fistulas (DAVFs) are amenable to endovascular treatment with Onyx. However, reports on complications caused by this technique have been limited. We present the initial Beijing Tiantan Hospital experience with adverse events related to transarterial Onyx embolization for DAVFs.

MATERIALS AND METHODS

Between September 2005 and February 2008, a total of 40 patients with DAVFs were treated at our institute with Onyx-18. There were 11 women and 29 men with a mean age of 43.15 years (age range, 23-60 years). We reviewed the clinical presentation, angiographic features, treatment, and outcome.

RESULTS

In 40 patients, total obliteration was achieved in 25 DAVFs (62.5%), with the remaining 15 patients not cured with residual shunts. Complications occurred in 9 patients, 5 DAVFs were located at tentorium, 2 were located at the transverse-sigmoid sinus, 1 was found at the inferior petrosal sinus, and 1 was found at the cavernous sinus, leading to permanent disability in 3 patients (morbidity, 7.5%). Complications included reflexive bradyarrhythmia in 3 (7.5%) patients, hemifacial hypoesthesia in 3 (7.5%) patients, hemifacial palsy in 2 (5%) patients, posterior fossa infarction in 2 (5%) patients, jaw pain in 1 (2.5%) patient, microcatheter gluing in 1 (2.5%) patient, hallucinations in 1 (2.5%) patient, and Onyx migration in 1 (2.5%) patient.

CONCLUSION

Although complete cure can be achieved by transarterial embolization with Onyx, the potential for serious complications exists with this procedure.

Development of a cell-based assay for monitoring hepatitis C virus ns3/4a protease activity

Hepatitis C virus (HCV) NS3/4A (non-structural 3 and 4 B) protease plays a key role in the processing of polyprotein precursor and it becomes an attractive target for antiviral drug discovery. We developed a cell-based assay for monitoring of the NS3/4A protease activity in mammalian cells that is an important step in screening of specific drugs against the protease. The recombinant caspase 3 (rCasp3) was used as the specific substrate for NS3/4A protease. The endogenous cleavage sites in the procaspase 3 molecule were substituted by decapeptides specific for NS3/4A protease. The activation of rCasp3 depended on its specific cleavage by NS3/4A protease and resulted in an apoptosis of stable cells expressing the protease. The difference in cell viability between the cells expressing NS3/4A protease transfected with rCasp3 and the counterparts pretreated with NS3/4A protease inhibitors could be estimated by a spectrophotometry based on 3-(4,5-dimethylthioazol- 2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) staining of cells in microplates. Thus, we developed a simple and cost-effective colorimetric assay for evaluating NS3/4A protease activity enabling the screening of candidate NS3/4A protease inhibitors.

Trigeminocardiac reflex in embolization of intracranial dural arteriovenous fistula

We report a case of immediate reproducible and reflexive response of asystole upon stimulation of Onyx injection during embolization of a tentorial dural arteriovenous fistula in a 53-year-old man. Upon recognition of the reflexive relationship between Onyx injection and increased vagal tone, the patient was given anticholinergic in an effort to block cholinergic hyperactivity. After atropine was given, no further dysrhythmias occurred.

In vivo DNA-protein interactions at hypersensitive site 3.5 of the human beta-globin locus control region

Using ligation-mediated polymerase chain reaction and in vivo footprinting methods to study the status of DNA-protein interactions at hypersensitive site 3.5 (HS3.5) of the locus control region in K562 and HEL cells, we found that there was protein occupancy in vivo at HS3.5 in both cell lines and the status of DNA-protein interaction was different between K562 and HEL. These data provide direct evidence that specific nuclear factor-DNA complexes form in vivo at functionally important sequence motifs of the HS3.5 in erythroid cells. This indicates that HS3.5 may play an important role in the regulation of the beta-globin gene cluster. K562 is a human erythroleukemia cell line in which the embryonic epsilon-globin gene is predominantly expressed, while the HEL cell line expresses predominantly the fetal beta-globin genes. Thus, HS3.5 might also be involved in the regulation of developmental stage-specific expression of beta-globin genes. Our results are also consistent with the model that each hypersensitive site acts as a functional unit and HS3.5 may facilitate the formation of the HS3 functional unit.