COVID‐19 outbreak as a probable cause of increased risk of intracranial rebleeding in partially treated cerebral arteriovenous malformations

Pre-radiosurgical embolization was carried out using cyanoacrylate in seven of 13 patients with cerebral arteriovenous malformations (AVMs) treated by stereotactic radiosurgery (SRS) with a linear accelerator (LINAC). The aim of embolization before SRS was the reduction of AVM volume and/or the elimination of vascular structures bearing an increased risk of haemorrhage. Staged-volume SRS was also performed in two patients because of residual irregular shaped nidus of AVMs even after the embolizations. Complete obliteration of the AVM nidus on angiogram was presented in five patients with embolizations (including one with staged-volume SRS) and in three of six patients with SRS alone, during follow-up periods after radiosurgery. No patients experienced haemorrhagic events after SRS. Although transient neurological symptoms were observed after embolizations in two patients, no permanent neurological deficits were presented in all patients with SRS. Pre-radiosurgical embolization may allow the effective influence on irradiation therapy in relatively large AVMs and promote more frequent obliteration in more small sized AVMs compared to those with SRS alone. However, further study must be needed to determine whether staged-volume SRS provides a high rate of AVM obliteration and its safeness.

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Risk factors for subsequent hemorrhage in patients with cerebral arteriovenous malformations

Journal of Neurosurgery ◽

10.3171/jns-07/11/0965 ◽

2007 ◽

Vol 107 (5) ◽

pp. 965-972 ◽

Cited By ~ 112

Author(s):

Shigeki Yamada ◽

Yasushi Takagi ◽

Kazuhiko Nozaki ◽

Ken-ichiro Kikuta ◽

Nobuo Hashimoto

Keyword(s):

Risk Factors ◽

Arteriovenous Malformations ◽

Venous Drainage ◽

University Hospital ◽

Neurological Deficits ◽

First Year ◽

Cerebral Arteriovenous Malformations ◽

Drainage Pattern ◽

Bleeding Rate ◽

Increased Risk

Object The aim of this study was to identify the natural history of untreated cerebral arteriovenous malformations (AVMs) and the risk factors for subsequent hemorrhage after an initial AVM diagnosis. Methods The authors studied 305 consecutive patients with AVMs at the Kyoto University Hospital between 1983 and 2005. These patients were followed up until the first subsequent hemorrhage, the start of any treatment, or the end of 2005. Possible risk factors that were investigated included age at initial diagnosis, sex, type of initial presentation, size and location of the AVM nidus, and the venous drainage pattern. Subsequent hemorrhage occurred in 26 patients from the hemorrhagic group during 380 patient–years, and in 16 patients from the nonhemorrhagic group during 512 patient–years. Results The annual bleeding rate in the hemorrhagic group was 6.84% after the initial hemorrhage; however, that rate decreased in the first 5 years (15.42% in the first year, 5.32% in the subsequent 4 years, and 1.72% in more than 5 years). In the nonhemorrhagic group (annual bleeding rate of 3.12%), the patients initially presenting with headaches (annual bleeding rate of 6.48%) or asymptomatic presentations (annual bleeding rate of 6.44%) had a higher risk for subsequent hemorrhage. Conversely, those patients presenting with seizures (annual bleeding rate of 2.20%) or neurological deficits (annual bleeding rate of 1.73%) had a lower risk. A significantly increased risk (p < 0.05) of rebleeding was found among children (hazard ratio [HR] = 2.69), females (HR = 2.93), or patients with deep-seated AVMs (HR = 3.07). Conclusions Children, females, and patients with deep-seated AVMs had a threefold increased risk of rebleeding after an initial cerebral AVM. This increased risk was highest in the first year after the initial hemorrhage, and thereafter gradually decreased.

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Natural history of brain arteriovenous malformations: a systematic review

Neurosurgical FOCUS ◽

10.3171/2014.6.focus14250 ◽

2014 ◽

Vol 37 (3) ◽

pp. E7 ◽

Cited By ~ 74

Author(s):

Isaac Josh Abecassis ◽

David S. Xu ◽

H. Hunt Batjer ◽

Bernard R. Bendok

Keyword(s):

Natural History ◽

Arteriovenous Malformations ◽

Venous Drainage ◽

Cerebral Arteriovenous Malformations ◽

Brain Arteriovenous Malformations ◽

Increased Risk ◽

Risk Of Rupture ◽

History Of ◽

Arterial Aneurysms

Object The authors aimed to systematically review the literature to clarify the natural history of brain arteriovenous malformations (BAVMs). Methods The authors searched PubMed for one or more of the following terms: natural history, brain arteriovenous malformations, cerebral arteriovenous malformations, and risk of rupture. They included studies that reported annual rates of hemorrhage and that included either 100 patients or 5 years of treatment-free follow-up. Results The incidence of BAVMs is 1.12–1.42 cases per 100,000 person-years; 38%–68% of new cases are first-ever hemorrhage. The overall annual rates of hemorrhage for patients with untreated BAVMs range from 2.10% to 4.12%. Consistently implicated in subsequent hemorrhage are initial hemorrhagic presentation, exclusively deep venous drainage, and deep and infrantentorial brain location. The risk for rupture seems to be increased by large nidus size and concurrent arterial aneurysms, although these factors have not been studied as thoroughly. Venous stenosis has not been implicated in increased risk for rupture. Conclusions For patients with BAVMs, although the overall risk for hemorrhage seems to be 2.10%–4.12% per year, calculating an accurate risk profile for decision making involves clinical attention and accounting for specific features of the malformation.

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Endovascular Therapy Followed by Stereotactic Radiosurgery for Cerebral Arteriovenous Malformations

Rivista di Neuroradiologia ◽

10.1177/197140099500800628 ◽

1995 ◽

Vol 8 (6) ◽

pp. 163-166

Author(s):

Y. Arai ◽

Y. Handa ◽

H. Ishii ◽

Y. Ueda ◽

H. Uno ◽

...

Keyword(s):

Stereotactic Radiosurgery ◽

Arteriovenous Malformations ◽

High Rate ◽

Neurological Deficits ◽

Cerebral Arteriovenous Malformations ◽

Increased Risk ◽

Irradiation Therapy ◽

Complete Obliteration ◽

Vascular Structures

Pre-radiosurgical embolization was carried out using cyanoacrylate in seven of 13 patients with cerebral arteriovenous malformations (AVMs) treated by stereotactic radiosurgery (SRS) with a linear accelerator (LINAC). The aim of embolization before SRS was the reduction of AVM volume and/or the elimination of vascular structures bearing an increased risk of haemorrhage. Staged-volume SRS was also performed in two patients because of residual irregular shaped nidus of AVMs even after the embolizations. Complete obliteration of the AVM nidus on angiogram was presented in five patients with embolizations (including one with staged-volume SRS) and in three of six patients with SRS alone, during follow-up periods after radiosurgery. No patients experienced haemorrhagic events after SRS. Although transient neurological symptoms were observed after embolizations in two patients, no permanent neurological deficits were presented in all patients with SRS. Pre-radiosurgical embolization may allow the effective influence on irradiation therapy in relatively large AVMs and promote more frequent obliteration in more small sized AVMs compared to those with SRS alone. However, further study must be needed to determine whether staged-volume SRS provides a high rate of AVM obliteration and its safeness.

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Embolization of Cerebral Arteriovenous Malformations to Enhance the Success of Subsequent Radiosurgery

Interventional Neuroradiology ◽

10.1177/15910199980040s126 ◽

1998 ◽

Vol 4 (1_suppl) ◽

pp. 121-126 ◽

Cited By ~ 4

Author(s):

S. Miyachi ◽

T. Tanaka ◽

T. Kobayashi ◽

Y. Kida ◽

M. Negoro ◽

...

Keyword(s):

Arteriovenous Malformations ◽

Gamma Knife Radiosurgery ◽

Size Reduction ◽

Diffuse Type ◽

Cerebral Arteriovenous Malformations ◽

Shunt Flow ◽

Increased Risk ◽

Mean Size ◽

The Mean ◽

Embolic Materials

We studied angiographic changes in embolized arteriovenous malformations (AVMs) by comparing pre- and postembolization angiograms and angiograms preceding radiosurgery. This study sought factors determining the usefulness of embolization as a pretreatment to enhance the success of subsequent radiosurgery. Thirty patients with cerebral AVMs treated in this manner over 4 years were studied. In these cases AVMs were embolized with cyanoacrylate and were treated with Gamma-knife radiosurgery. The mean size of the AVM nidus was reduced by a fraction of seven following embolization. The subsequent angiogram for planning radiosurgery showed further nidus reduction in 10 AVMs, no change in 12, and regrowth in 8. In all size-reduction cases the nidus was sufficiently packed, and 2 AVMs had thrombosed completely before radiosurgery. All the regrowing AVMs were of diffuse type; 6 were associated with already-developed leptomeningeal channels, and the remaining 3 were fed by newly sprouted meningeal feeders. Five AVMs disappeared following radiosurgery, all representing size-reduction or no-change cases. Analysis of cases with regrowth showed increased risk of that event with feeder occlusion of a multi-axially supplied AVM, lack of reduction of shunt flow, or remaining meningeal feeders. On the other hand, when embolization as pretreatment prior to radiosurgery succeeds in producing a small, compacted, plexiform nidus with slow shunt flow, it furthers the likelihood of successful radiosurgery, Nidus embolization and occlusion of fistulous and meningeal feeders are mandatory, while proximal feeder occlusion and use of embolic materials which risk recanalization should be avoided to prevent nidus regrowth.

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