Intra- and post-operative acute hemorrhagic complications of Onyx embolization of brain arteriovenous malformations: A single-center experience

Background

The intra- and post-operative acute (within 72 h) hemorrhagic complications of endovascular treatment (EVT) for a brain arteriovenous malformation (BAVM) are disastrous. Thus, further experiential summaries are required to fully understand them.

Materials and methods

This was a retrospective study of 25 patients with consecutive BAVM who were treated via EVT with Onyx embolization and suffered intra- and post-operative acute hemorrhage. The clinical and imaging data of the patients were recorded, analyzed, and discussed.

Result

Twenty-five patients were aged 11–70 years (mean, 37.2 ± 16.1 years), of whom 12 were female (48%, 12/25). Of the 25 hemorrhagic complications, 17 (68%, 17/25) were intraoperative, and 8 (32%, 8/25) were post-operative and occurred between 1 and 12 h after EVT. Of 17 intraoperative hemorrhages, 13 (76.5%, 13/17) were due to high-pressure Onyx casting. Of eight post-operative hemorrhages, six (75%, 6/8) were attributed to normal perfusion pressure breakthrough. The degree of nidus Onyx embolization was more than 2/3 or complete in seven (87.5%, 7/8) BAVMs. Draining vein occlusion was observed in eight (32%, 8/25) of 25 BAVMs. After hemorrhage, conservative treatment was administered in 12 (48%, 12/25) cases, and surgical management was performed in other cases. There were eight cases of mortality; the remaining 17 patients had follow-up data. Among them, 15 patients had good outcomes, with Glasgow Outcome Scale scores of 5 and 4, accounting for 60% (15/25).

Conclusion

In EVT for BAVMs, intra- and post-operative acute hemorrhagic complications are disastrous; only 60% of patients have a good outcome. Therefore, high-pressure Onyx casting or casting too much Onyx at one time to pursue a high degree of nidus embolization should be performed cautiously, and primary draining vein occlusion should be avoided. In short, EVT needs to be performed carefully.

Hemorrhagic risk factors of endovascular onyx embolization of intracranial dural arteriovenous fistulas

BACKGROUND AND PURPOSE

Hemorrhagic complication is a disastrous complication of intracranial dural arteriovenous fistulas (DAVFs) embolization. This study was to analyze the possible risk factors for the hemorrhagic complication caused by endovascular embolization of DAVFs.

METHODS

From January 2012 to July 2016, a total of 267 patients with intracranial DAVFs received endovascular Onyx embolization at our hospital. The demographic information, clinical presentation, angiographic features, endovascular treatment and hemorrhagic complications were reviewed. Univariate and multivariate logistic regression analyses were performed to evaluate the risk factors contributing to the post-procedural hemorrhagic complications.

RESULTS

In 267 patients of DAVF treated with endovascular embolization, procedure-related hemorrhagic complication occurred in 12 (4.5%) patients. Univariate and multivariate logistic regression analyses showed that the pial arterial supplier (OR 13.630; 95% CI, 1.556-119.368; P = 0.018), giant venous aneurysm (OR 15.196; 95% CI, 2.505-92.183; P = 0.003) and Onyx volume ≥ 6 ml (OR 1.138; 95% CI, 1.006-1.288; P = 0.040) were significant factors associated with these hemorrhagic complications.

CONCLUSIONS

Hemorrhagic complications associated with endovascular DAVF embolization are not negligible. The pial arterial supplier, giant venous aneurysm and higher Onyx volume in one session may be risk factors for endovascular DAVF embolization.

Complications of Endovascular Treatments for Brain Arteriovenous Malformations: A Nationwide Surveillance

BACKGROUND AND PURPOSE

Embolization is widely performed to treat brain arteriovenous malformations, but little has been reported on factors contributing to complications. We retrospectively reviewed a nationwide surveillance to identify risk factors contributing to complications and short-term clinical outcomes in the endovascular treatment of brain arteriovenous malformations.

MATERIALS AND METHODS

Data for endovascular treatment of brain arteriovenous malformations were extracted from the Japanese nationwide surveillance. Patient characteristics, brain arteriovenous malformation features, procedures, angiographic results, complications, and clinical outcomes at 30 days postprocedure were analyzed.

RESULTS

A total of 1042 endovascular procedures (788 patients; mean, 1.43 ± 0.85 procedures per patient) performed in 111 institutions from 2010 to 2014 were reviewed. Liquid materials were used in 976 procedures (93.7%): to perform presurgical embolization in 638 procedures (61.2%), preradiosurgical embolization in 160 (15.4%), and as sole endovascular treatment in 231 (22.2%). Complete or near-complete obliteration of brain arteriovenous malformations was obtained in 386 procedures (37.0%). Procedure-related complications occurred in 136 procedures (13.1%), including hemorrhagic complications in 59 (5.7%) and ischemic complications in 57 (5.5%). Univariate analysis identified deep venous drainage, associated aneurysms, infratentorial location, and preradiosurgical embolization as statistically significant risk factors for complications. Multivariate analysis showed that embolization of brain arteriovenous malformations in the infratentorial location was significantly associated with complications. Patients with complications due to endovascular procedures had worse clinical outcomes 30 days after the procedures than those without complications.

CONCLUSIONS

Complications arising after endovascular treatment of brain arteriovenous malformations are not negligible even though they may play a role in adjunctive therapy, especially in the management of infratentorial brain arteriovenous malformations.

Association of intracranial arteriovenous malformation embolization with more rapid rate of perfusion in the peri-nidal region on color-coded quantitative digital subtraction angiography

BACKGROUND

Hemodynamic alterations post-embolization of intracranial arteriovenous malformations (AVMs) may cause delayed edema/hemorrhage in brain parenchyma adjacent to the lesion.

OBJECTIVE

To quantify and compare cerebral perfusion changes in the peri-AVM territory pre- and post-embolization using color-coded quantitative digital subtraction angiography (q-DSA).

METHODS

Pediatric intracranial AVM embolization procedures performed over a 5 year period were included. DSA images of all patients were retrospectively assessed using syngo iFlow. Regions of interest (ROI) were selected on anteroposterior and lateral q-DSA views: three in the peri-AVM region; two in parenchyma distant from the AVM. Time-to-peak (TTP) contrast enhancement of ROIs and ∆TTP (TTP at the selected ROI minus TTP at either the ipsilateral internal carotid/vertebral artery) were measured.

RESULT

19 pediatric patients with 19 AVMs (9 males/10 females, mean age 12 years) underwent intracranial AVM embolization: 15/19 AVMs were supplied by the anterior circulation and 4/19 by the posterior circulation. Blood flow was significantly slower post-embolization in the draining vein (19/19) (p<0.01), and the venous sinus outflow (17/19) (p<0.01), by mean difference of 2.01±1.31 s and 1.74±2.04 s. There was significantly increased peri-AVM parenchymal perfusion post-embolization (∆TTP=2.20±0.48 s) compared with pre-embolization (∆TTP=2.52±0.42 s), by an average ∆TTP of 0.33±0.53 s (p=0.014). In contrast, there was no perfusion difference (∆TTP=0.03±0.20 s, p=0.8) between pre- and post-embolization in the distant parenchyma. The size of the AVM was not correlated with change in peri-nidal parenchymal perfusion (r=-0.136, p=0.579).

CONCLUSION

This study demonstrates more rapid perfusion in the peri-nidal brain parenchyma post-embolization of the AVM, which supports the theory that increased perfusion in normal tissue surrounding the AVM after embolization may underlie some post-procedural complications.

Hemorrhagic complications after endovascular treatment of cerebral arteriovenous malformations

BACKGROUND AND PURPOSE

Intracranial hemorrhage is the most severe complication of brain arteriovenous malformation treatment. We report our rate of hemorrhagic complications after endovascular treatment and analyze the clinical significance and potential mechanisms, with emphasis on cases of delayed hemorrhage after uneventful embolization.

MATERIALS AND METHODS

During a 10-year period, 846 embolization procedures were performed in 408 patients with brain AVMs. Any cases of hemorrhagic complications were identified and divided into those related or unrelated to a periprocedural arterial tear (during catheter navigation or catheter retrieval). We analyzed the following variables: sex, age, hemorrhagic presentation, Spetzler-Martin grade, size of the AVM, number of embolized pedicles, microcatheter used, type and volume of liquid embolic agent injected, and the presence of a premature venous occlusion. Univariate and multivariate multiple regression analyses were performed to identify risk factors for hemorrhagic complications.

RESULTS

A hemorrhagic complication occurred in 92 (11%) procedures. Forty-four (48%) complications were related to a periprocedural arterial perforation, and 48 (52%) were not. Hemorrhagic complications unrelated to an arterial perforation were located more commonly in the cerebral parenchyma, caused more neurologic deficits, and were associated with worse prognosis than those in the arterial perforation group. Only premature venous occlusion was identified as an independent predictor of hemorrhagic complication in the nonperforation group. Premature venous occlusion was significantly related to the ratio of Onyx volume to nidus diameter.

CONCLUSIONS

Higher injected volume of embolic agent and deposition on the venous outflow before complete occlusion of the AVM may account for severe hemorrhagic complications.

Critical appraisal of endovascular treatment of brain arteriovenous malformation using Onyx in a series of 92 consecutive patients

BACKGROUND

The introduction of Onyx has led us to adopt a new treatment approach for brain arteriovenous malformation (AVM), using endovascular embolization with Onyx as the first line treatment with a curative intent. The aim of the present report is to evaluate our results using this strategy, with special emphasis on angiographic characteristics affecting treatment risks and success rates.

METHODS

From October 2006 to December 2009, 92 consecutive patients harboring brain AVM were treated with Onyx during 177 procedures.

RESULTS

Endovascular treatments were completed in 68 out of 92 patients. Median number of procedures was two. Complete obliteration using embolization exclusively was achieved in 25 patients, resulting in a 37 % cure rate in patients who concluded treatments (25/68), and 27 % in the cohort. In Spetzler-Martin grades 1 & 2 AVMs, complete obliteration was achieved in 48 % of the cases. Complete obliteration rates were significantly higher in lesions with superficial big feeding arteries. There were 15 bleeding complications during 177 embolization sessions (8.4 % per procedure); seven cases resolved in less than 3 months. Permanent disability rate was 6.5 %; mortality rate was 2.2 %. Bleeding was related to the use of the microcatheter/guidewire in six cases and to the use of the embolization material in nine, the amount of Onyx injected was significantly higher in those nine cases.

CONCLUSIONS

Embolization of brain AVM using Onyx and detachable tip microcatheters results in a relatively high rate of complete obliteration. Angioarchitecture of the lesion can predict treatment success. Higher amounts of Onyx injected per session increase the bleeding risk.