Overview of perianeurysmal edema after the endovascular management of cerebral aneurysms. A pooled analysis of 48 cases.

doi:10.21203/rs.3.rs-4824344/v1

Download PDF

Systematic Review

Overview of perianeurysmal edema after the endovascular management of cerebral aneurysms. A pooled analysis of 48 cases.

https://doi.org/10.21203/rs.3.rs-4824344/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this latest preprint version

Background:

Perianeurysmal edema occurring after endovascular treatment for cerebral aneurysms is uncommon compared to surgical clipping. The clinical aspects and the exact explanation is poorly understood.

Methods:

We searched PubMed, Google Scholar, Web of Science. We used the following keywords “endovascular management of cerebral aneurysms” “perianeurysmal cerebral edema”, perianeurysmal cerebral edema after endovascular treatment endovascular treatment” “intracranial aneurysms with perianeurysmal edema” “vessel wall enhancement after endovascular therapy”. For each case, demographic, clinicopathological, therapeutic and follow-up data were gathered and analyzed.

Results:

Perianeurysmal edema after endovascular treatment has a clear female predilection, with a male: female ratio of (12 (25%):29 (60.41%)). The average time from EVT to the onset of edema ranged from one day to about eight years. The aneurysm dimension ranged from 6.8 to 25 mm as the largest size reported. Most patients were asymptomatic 18(37.5 %), and headache was the presenting symptom in 10 patients (20.8%). Aneurysmal wall enhancement was reported in (16 (33.3 %)) patients with perianeurysmal edema. About 12 patients (25%) developed post EVT hydrocephalus. The most common coil used was the platinum type 31 (64.58%). Most of the patients were treated expectantly with follow up 17 (35.41 %), while steroids were used only in 14 (29.16%) patients. Most of the patients have their edema resolved 29 (60.41%) or stable 9 (37.5%).

Conclusion:

There is growing evidence supporting the incidence of post embolization inflammatory reactions involving the vessel wall and the surrounding parenchyma, however, the exact clinical perspectives and the predisposing factors are not fully uncovered. This analysis highlights the possible presentations, and short term outcome of patients presenting with perianeurysmal edema after endovascular management of cerebral aneurysms.

Neurosurgery

cerebral aneurysms

endovascular surgery

perianeurysmal edema.

Aneurysmal subarachnoid hemorrhage is a major cause of morbidity and mortality. Recently, several management strategies for aneurysmal subarachnoid hemorrhage have been introduced. Currently, endovascular surgical management has replaced surgical clipping as a main treatment option [1]. Perianeurysmal edema is a common imaging finding event and reported in both treated and untreated aneurysms. Surgical clipping is associated with postoperative edema due to the surgical manipulation and brain retraction. Perianeurysmal edema after endovascular management of cerebral aneurysms is an uncommon poorly understood phenomenon. A reactionary inflammatory or granulomatous response to the coil material has been reported following endovascular embolization [2]. In certain cases, edema is suggested to be related to aneurysmal thrombosis [3]. Early and delayed hydrocephalus following the endovascular management of cerebral aneurysms is poorly understood. Delayed nonischemic cerebral enhancing (NICE) lesions are imaging findings that were reported after the endovascular treatment of cerebral aneurysms.

The clinical presentations in this context are nonspecific and include headache, vision problems, seizures, speech problems or disturbed conscious level [4,5,6]. Post-intervention neurological examination and follow up imaging can guide for early diagnosis. The treatment protocols are variable and include observation, steroid therapy, symptomatic treatment or re-embolization. We conducted a pooled analysis of the reported cases that describe perianeurysmal edema after the endovascular management of cerebral aneurysm. We tried to find out the predisposing factors that could predict its incidence and outcome.

Given the lack of clinical experience reported in the literature in terms of this subject, we searched PubMed, Google Scholar, Web of Science. We used the following keywords “endovascular management of cerebral aneurysms” “perianeurysmal cerebral edema”, perianeurysmal cerebral edema after endovascular treatment EVT” “intracranial aneurysms with perianeurysmal edema” “vessel wall enhancement after endovascular therapy”.Also, we examined manually references in the articles in which the data registry search returned. We included only the articles that describe the complete data for the patients diagnosed with cerebral perianeurysmal edema after endovascular treatment EVT. Other criteria for case selection include English language, aneurysms only treated with EVT, aneurysms with post-treatment perianeurysmal edema. Finally, we identified 50 case reports. Cases were reported either as isolated case reports or a part of case series. We excluded studies with incomplete data, non-English language and aneurysms treated with interventions other than EVT. Statistical analyses were carried out using statistical software (Jamovi 2.3.28). For each case, demographic, clinicopathological, therapeutic and follow-up data were gathered and analyzed from 50 cases. In Table 1, we collected demographic information including age, sex, aneurysm size, number of coils, time to edema (day), time of edema onset after treatment, Fisher grading, aneurysm location, clinical presentation, preoperative edema, and preoperative steroid use, post EVT aneurysm expansion, aneurysm thrombosis,, aneurysmal wall enhancement, complications, post treatment hydrocephalus, parenchymal embedding, coil type, coiling method, and outcome. All categorical variables were presented as frequencies and percentages. To ensure the validity of statistical analysis, the normality of continuous data was checked using the Kolmogorov-Smirnov test. When appropriate, mean, standard deviation (SD), median, and interquartile range (IQR) values were presented for continuous data variables.

According to the analysis of data from these reported cases, perianeurysmal edema after EVT has a clear female predilection, with a male: female ratio of (12 (25%):29 (60.41%)).The mean age at diagnosis was 57.59 (±13.7). The average time from EVT to the onset of edema ranged from one day to about eight years. The aneurysm dimension ranged from 6.8 to 25 mm as the largest size reported. The most frequent location reported involves the ICA aneurysms (18 (37.5 %)) followed by the basilar tip aneurysms (10 (20.83 %)). Most patients were asymptomatic 18 (37.5 %), and headache was the presenting symptom in 10 patients (20.8%), while (3 (6.25%)) presented with seizures. Aneurysm expansion was observed in (12 (25%)) patients with perianeurysmal edema. Aneurysmal wall enhancement was also reported in (16 (33.3 %)) patients with perianeurysmal edema. There are about (24 (50%)) patients who had aneurysms with parenchymal embedding. About 12 patients (25%) developed post EVT hydrocephalus, about 7 of them were treated with ventriculoperitoneal shunts, one with third ventriculostomy, one with external drain, two with lumbar taps and one did not receive treatment. The duration that patients take to develop hydrocephalus ranged from 2 to 540 days with a mean of 195 (± 179). The most common treatment method in this cohort of patients was simple coiling 30 (62.5 %) and the most common coil that used was the platinum type 31 (64.58%). All patients did not show any imaging features suggestive of preoperative edema. Most of the patients were treated expectantly with follow up 17 (35.41 %), while steroids were used only in 14 (29.16%) patients. Regarding recovery state, most of the patients have their edema resolved 29 (60.41%) or stable 9 (37.5%).

Endovascular interventions have become the standard option for the management of cerebral aneurysms compared to surgical clipping. Since 1990, detachable coils designed by Guglielmi were considered an innovation in the era of modern endovascular neurosurgery [7]. Significant advances in the coil industry and coil assisting devices have grown up significantly [8]. Assisting devices include balloons and stents to maintain the patency of the parent vessel and to promote proper coil packaging [9]. Balloon assisted coiling helps in proximal control in case of procedural aneurysmal rupture and prevents coil migration during embolization [10].

The main complications of endovascular interventions for cerebral aneurysms include aneurysmal perforations and thromboembolic events. The incidence, and management of these complications is well established. On the other hand, perianeurysmal vasogenic edema after endovascular embolization is not extensively studied, however, there is still uncertainty about the exact mechanism. Postoperative imaging may show perianeurysmal edema, aneurysmal wall enhancement, recanalization and occasionally, delayed hydrocephalus [11]. De novo edema after coil embolization has been frequently reported in some patients, while others with preoperative edema had their edema resolved after aneurysm occlusion [12].

The clinical significance and impact of perianeurysmal edema after embolization is not well-defined. Arterial pulsatile flow that stresses the aneurysmal wall and could be transmitted to the surrounding brain parenchyma could be a contributing factor [13]. Aneurysmal expansion, and thrombus formation could exert a mass effect on the surrounding brain causing edema [14]. Aneurysm thrombosis exerts a mass effect and can induce an inflammatory reaction. In a case report, a giant vertebral artery aneurysm continued to grow after endovascular treatment, and MRI showed perianeurysmal enhancement. Histological examination of the surrounding tissue showed inflammation and neovascularization surrounding the coils [15]. Moreover, inflammatory mediators produced in the aneurysmal wall could contribute to post-coiling thrombus formation exacerbating perianeurysmal edema Fig. 1 [16]. Postmortem examination of the wall of aneurysms treated with embolization suggested an inflammatory reaction that is associated with aneurysmal wall enhancement [17]. Some patients develop post-embolization hydrocephalus. The mechanism by which those patients develop hydrocephalus is not fully understood. Patients with unruptured aneurysms treated with bioactive coils developed hydrocephalus [18]. It is hypothesized that embolization coils could induce inflammatory meningitis that might cause a low grade obstructive hydrocephalus [19].

The incidence of perianeurysmal edema is 7.6–8.6% on regular postembolization MRI examination [20]. Typical radiological features include punctuate, nodular or annular areas of enhancement and T2-hyperintensities involving the leptomeninges, cortex and subcortical areas close to the treated aneurysm. The clinical presentations are variable and include headache, seizure, motor deficit, altered mental status, visual, and speech disturbances [12, 13, 21]. Female sex was associated with a higher incidence of PE after EVT. Generally, women have a higher risk of aneurysmal rupture than men [24, 28]. Several studies have reported that females have a higher risk for cerebral aneurysm formation than men and they are more likely to have multiple cerebral aneurysms than males which may explain the increased incidence of perianeurysmal post embolization edema among females [29, 30]. The exact prevalence of PE in patients with cerebral aneurysms treated with EVT is unknown.

PE occurred with all aneurysmal sizes and there was no predilection for large sized ones. Through our pooled analysis, we noticed that most patients were asymptomatic, while the most frequent presentation was headache [22, 23, 24] followed by seizures due to cortical irritation. However, several patients with parenchymal embedding of the aneurysms were completely asymptomatic. The most common aneurysms associated with post ETV edema were main ICA and bifurcation aneurysms followed by basilar tip aneurysms. We noticed that a large number of the aneurysms were embedded in the brain parenchyma which may explain the impact of dynamic water hammer flow on the wall and the surrounding brain. Based on pulsatility theory, careful attention should be given to large aneurysms in contact with parenchyma, and close to the brainstem.

Interestingly, we noticed that the most common coil used was the platinum type, and edema was less observed with the use of flow diversion and stents. The time of edema onset is highly variable from a single day to several years following EVT, indicating the need for long-term follow-up protocols for the late detection of PE. Factors that predispose to the differential onset of edema are not well-defined. In a certain case report, it took two days after EVT to develop edema, while in others it took more than a year [22, 23] Aneurysm recanalization and expansion was reported in about 12 patients, suggesting aneurysmal incomplete occlusion as a possible etiology for PE. A second endovascular intervention in those cases with aneurysm expansion is required to completely occlude the aneurysm which may potentially improve the edema. Steroid therapy is considered the first line treatment for post-embolization perianeurysmal edema [25, 26]. In most of the patients, symptoms resolved without treatment, and patients who presented with seizures were treated with anti-seizure medications. The follow up of seizures incidence over a long term follow up is not available in the available case reports. There is no general consensus about the management of post-endovascular perianeurysmal edema. If the edema was related to aneurysm expansion or recanalization, a second treatment or embolization would be the best treatment option [6, 27].

Limitations:

Due to the infrequent occurrence of post ETV PE, the sample size of available case reports is small. Our heterogeneous data and the small sample size challenged the statistical robustness, which further limited the pooled analysis. A larger sample would allow for more detailed analysis. The unavailability of several studies data and reported results of the included literature further limited our review findings. The short follow up periods do not allow us to establish a proper evidence based outcome assessment. The difference of the degree of edema or inflammatory reactions stratified by the method of embolization is not well known in human studies. In experimental animal aneurysms, inflammatory and wound healing molecules were higher in coiled aneurysms than following flow diversion, however, this comparison is not substantiated in humans [43]. Researchers should recruit animal models for properly identifying the exact mechanism of edema that could affect the brain after endovascular interventions for cerebral aneurysms.

There is growing evidence of reporting on adverse post-embolization inflammatory reactions, and particularly on perianeurysmal edema. It should be considered in the differential diagnosis of causes of unusual neurological symptoms after EVT of cerebral aneurysms. Robust multi-centered clinical studies with long term follow up intervals should be recruited to evaluate the factors determining the incidence of post embolization perianeurysmal edema.

Batista S, Oliveira LB, Filho JAA, Abreu LV, Andreão FF, Palavani LB, Bertani R, Alves Filho CAF, de Oliveira Braga F, Machado EAT, da Mata Pereira PJ, Filho PN, Pereira VM. Endovascular treatment of mycotic aneurysms: An update meta-analysis. Clin Neurol Neurosurg. 2024 Jan; 236:108068.
Tomokiyo M, Kazekawa K, Onizuka M, Aikawa H, Tsutsumi M, Ikoh M, Kodama T, Nii K, Matsubara S, Tanaka A. Mechanisms of perianeurysmal edema following endovascular embolization of aneurysms. Interv Neuroradiol. 2007 Mar 15;13 Suppl 1(Suppl 1):145-50.
Craven I, Patel UJ, Gibson A, Coley SC. Symptomatic perianeurysmal edema following bare platinum embolization of a small unruptured cerebral aneurysm. AJNR Am J Neuroradiol 2009; 30:1998-2000
Su IC, Willinsky RA, Fanning NF, Agid R. Aneurysmal wall enhancement and perianeurysmal edema after endovascular treatment of unruptured cerebral aneurysms. Neuroradiology. 2014 Jun;56(6):487-95.
Sim KJ, Yan B, Dowling RJ, Mitchell PJ. Intracranial aneurysms with perianeurysmal edema: long-term outcomes post-endovascular treatment. J Neuroradiol. 2015 Apr;42(2):72-9.
Horie N, Kitagawa N, Morikawa M, Tsutsumi K, Kaminogo M, Nagata I. Progressive perianeurysmal edema induced after endovascular coil embolization. Report of three cases and review of the literature. J Neurosurg. 2007 May;106(5):916-20
Campos JK, Lien BV, Wang AS, Lin LM. Advances in endovascular aneurysm management: coiling and adjunctive devices. Stroke Vasc Neurol. 2020 Mar 15;5(1):14-21.
Jiang B, Paff M, Colby GP, Coon AL, Lin LM. Cerebral aneurysm treatment: modern neurovascular techniques. Stroke Vasc Neurol. 2016 Oct 25;1(3):93-100
Zhu Y, Zhang H, Zhang Y, Wu H, Wei L, Zhou G, Zhang Y, Deng L, Cheng Y, Li M, Santos HA, Cui W. Endovascular Metal Devices for the Treatment of Cerebrovascular Diseases. Adv Mater. 2019 Feb;31(8): e1805452.
Piotin M, Blanc R, Spelle L, Mounayer C, Piantino R, Schmidt PJ, Moret J. Stent-assisted coiling of intracranial aneurysms: clinical and angiographic results in 216 consecutive aneurysms. Stroke. 2010 Jan;41(1):110-5.
White JB, Cloft HJ, Kallmes DF. But did you use HydroCoil? Perianeurysmal edema and hydrocephalus with bare platinum coils. AJNR Am J Neuroradiol. 2008 Feb;29(2):299-300.
Horie N, Kitagawa N, Morikawa M, Tsutsumi K, Kaminogo M, Nagata I. Progressive perianeurysmal edema induced after endovascular coil embolization. Report of three cases and review of the literature. J Neurosurg. 2007 May;106(5):916-20.
Heros RC, Kolluri S. Giant intracranial aneurysms presenting with massive cerebral edema. Neurosurgery. 1984 Oct;15(4):572-7.
Krings T, Mandell DM, Kiehl TR, Geibprasert S, Tymianski M, Alvarez H, terBrugge KG, Hans FJ. Intracranial aneurysms: from vessel wall pathology to therapeutic approach. Nat Rev Neurol. 2011 Sep 20;7(10):547-59.
Iihara K, Murao K, Sakai N, Soeda A, Ishibashi-Ueda H, Yutani C, Yamada N, Nagata I. Continued growth of and increased symptoms from a thrombosed giant aneurysm of the vertebral artery after complete endovascular occlusion and trapping: the role of vasa vasorum. Case report. J Neurosurg. 2003 Feb;98(2):407-13.
Su IC, Willinsky RA, Fanning NF, Agid R. Aneurysmal wall enhancement and perianeurysmal edema after endovascular treatment of unruptured cerebral aneurysms. Neuroradiology. 2014 Jun;56(6):487-95.
Bavinzski G, Killer M, Gruber A, Reinprecht A, Gross CE, Richling B. Treatment of basilar artery bifurcation aneurysms by using Guglielmi detachable coils: a 6-year experience. J Neurosurg. 1999 May;90(5):843-52
Meyers PM, Lavine SD, Fitzsimmons BF, Commichau C, Parra A, Mayer SA, Solomon RA, Connolly ES Jr. Chemical meningitis after cerebral aneurysm treatment using two second-generation aneurysm coils: report of two cases. Neurosurgery. 2004 Nov;55(5):1222.
Ozaki M, Murayama Y, Ebara M, Takao H, Abe T. Delayed hydrocephalus after embolization of unruptured aneurysms using bare platinum coils: report of 2 cases. AJNR Am J Neuroradiol. 2011 Nov-Dec;32(10): E188-90.
Hayashi K, Kitagawa N, Morikawa M, Horie N, Kawakubo J, Hiu T, Tsutsumi K, Nagata I. Long-term follow-up of endovascular coil embolization for cerebral aneurysms using three-dimensional time-of-flight magnetic resonance angiography. Neurol Res. 2009 Sep;31(7):674-80
Shotar E, Law-Ye B, Baronnet-Chauvet F, Zeidan S, Psimaras D, Bielle F, Pecquet C, Navarro S, Rosso C, Cohen F, Chiras J, Di Maria F, Sourour N, Clarençon F. Non-ischemic cerebral enhancing lesions secondary to endovascular aneurysm therapy: nickel allergy or foreign body reaction? Case series and review of the literature. Neuroradiology. 2016 Sep;58(9):877-85.
Robinson AE, Phatouros CC. Perianeurysmal vasogenic oedema (PAVO) following aneurysm embolisation: a unique case of asymptomatic long-term progression and review of the literature. BMJ Case Rep. 2018 Sep 28;2018:bcr2018225625
Takeshita T, Horie N, Fukuda Y, So G, Hayashi K, Morikawa M, Suyama K, Nagata I. A Ruptured Basilar Tip Aneurysm Showing Repeated Perianeurysmal Edema after Endovascular Coil Embolization: Case Report. Neurol Med Chir (Tokyo). 2015;55(6):519-23.
Su IC, Willinsky RA, Fanning NF, Agid R. Aneurysmal wall enhancement and perianeurysmal edema after endovascular treatment of unruptured cerebral aneurysms. Neuroradiology. 2014 Jun;56(6):487-95.
Hammoud D, Gailloud P, Olivi A, Murphy KJ. Acute vasogenic edema induced by thrombosis of a giant intracranial aneurysm: a cause of pseudostroke after therapeutic occlusion of the parent vessel. AJNR Am J Neuroradiol. 2003 Jun-Jul;24(6):1237-9.
Halbach VV, Higashida RT, Dowd CF, Barnwell SL, Fraser KW, Smith TP, Teitelbaum GP, Hieshima GB. The efficacy of endosaccular aneurysm occlusion in alleviating neurological deficits produced by mass effect. J Neurosurg. 1994 Apr;80(4):659-66.
Zammit A, Tudose A, Khan N, Renowden S, Teo M. Perianeurysmal parenchymal cysts - Case series and literature review. Brain Spine. 2022 Jul 30;2:100920.
Zuurbier CCM, Molenberg R, Mensing LA, Wermer MJH, Juvela S, Lindgren AE, Jääskeläinen JE, Koivisto T, Yamazaki T, Uyttenboogaart M, van Dijk JMC, Aalbers MW, Morita A, Tominari S, Arai H, Nozaki K, Murayama Y, Ishibashi T, Takao H, Gondar R, Bijlenga P, Rinkel GJE, Greving JP, Ruigrok YM. Sex Difference and Rupture Rate of Intracranial Aneurysms: An Individual Patient Data Meta-Analysis. Stroke. 2022 Feb;53(2):362-369.
Liu H, Zhang T, Jiao S, Li B, Guan J, Wang YX. Epidemiological investigation of 264 sporadic cases of ruptured cerebral aneurysm at a single institution in southwest China. Neuropsychiatr Dis Treat. 2015 Jul 1;11:1609-14
Ostergaard JR, Høg E. Incidence of multiple intracranial aneurysms. Influence of arterial hypertension and gender. J Neurosurg. 1985 Jul;63(1):49-55.
Vu Dang L, Aggour M, Thiriaux A, Kadziolka K, Pierot L. Post-embolization perianeurysmal edema revealed by temporal lobe epilepsy in a case of unruptured internal carotid artery aneurysm treated with bare platinum coils. J Neuroradiol. 2009 Dec;36(5):298-300.
Misaki K, Uchiyama N, Mohri M, Hirota Y, Hayashi Y, Hamada J. Unusual delayed hydrocephalus after bare platinum coil embolization of an unruptured aneurysm. Neurol Med Chir (Tokyo). 2010;50(7):581-5.
Kobayashi H, Enomoto Y, Yamada T, Egashira Y, Nakayama N, Ohe N, Iwama T. Perianeurysmal cyst formation in the brainstem after coil embolization: illustrative case. J Neurosurg Case Lessons. 2022 May 30;3(22):CASE21690.
Cruz JP, Marotta T, O'Kelly C, Holtmannspötter M, Saliou G, Willinsky R, Krings T, Agid R. Enhancing brain lesions after endovascular treatment of aneurysms. AJNR Am J Neuroradiol. 2014 Oct;35(10):1954-8.
Pickett GE, Laitt RD, Herwadkar A, Hughes DG. Visual pathway compromise after hydrocoil treatment of large ophthalmic aneurysms. Neurosurgery. 2007 Oct;61(4):E873-4; discussion E874.
Marden FA, Putman CM. Perianeurysm edema with second-generation bioactive coils. Surg Neurol. 2008 Jun;69(6):627-32; discussion 632
Casey Spinelli, Aaron S. Dumont, Arthur Wang. Delayed-onset homonymous hemianopia following stent assisted coil embolization of a large internal carotid artery bifurcation aneurysm; case report and review of the literature,Interdisciplinary Neurosurgery,Volume 27,2022,101412,ISSN 2214-7519
Stracke CP, Krings T, Möller-Hartmann W, Mahdavi A, Klug N. Severe inflammatory reaction of the optic system after endovascular treatment of a supraophthalmic aneurysm with bioactive coils. AJNR Am J Neuroradiol. 2007 Aug;28(7):1401-2. doi: 10.3174/ajnr.A0550. PMID: 17698551; PMCID: PMC7977634.
Marchan EM, Sekula RF Jr, Ku A, Williams R, O'Neill BR, Wilberger JE, Quigley MR. Hydrogel coil-related delayed hydrocephalus in patients with unruptured aneurysms. J Neurosurg. 2008 Aug;109(2):186-90.
Sato M, Nakai Y, Takigawa T, Takano S, Matsumura A. Endoscopic third ventriculostomy for obstructive hydrocephalus caused by a large upper basilar artery aneurysm after coil embolization. Neurol Med Chir (Tokyo). 2012;52(11):832-4.
Takahashi S, Ishikawa M, Sagawa H, Wakabayashi H, Fujii S, Fujita K, Aoyama J, Hirai S, Sumita K. Delayed hydrocephalus and visual field defect due to perianeurysmal inflammation after treating a large unruptured aneurysm with flow diverter and coil: A case report. Clin Neurol Neurosurg. 2024 Feb;237:108130.
Jawid M, Ulrike B, Andreas B, Olav J. Late occurrence of a symptomatic perianeurysmal edema and wall enhancement after coil embolization. Neuroradiology. 2014 Dec;56(12):1129-32.
Rouchaud A, Johnson C, Thielen E, Schroeder D, Ding YH, Dai D, Brinjikji W, Cebral J, Kallmes DF, Kadirvel R. Differential Gene Expression in Coiled versus Flow-Diverter-Treated Aneurysms: RNA Sequencing Analysis in a Rabbit Aneurysm Model. AJNR Am J Neuroradiol. 2016 Jun;37(6):1114-21

Tables 1 to 2 are available in the Supplementary Files section

The authors declare no competing interests.

Tables.docx

Download PDF

Version 1

posted

You are reading this latest preprint version

Overview of perianeurysmal edema after the endovascular management of cerebral aneurysms. A pooled analysis of 48 cases.

Status:

Version 1

Abstract

Figures

Introduction

Methods

Results

Discussion

Limitations:

Conclusion

References

Tables

Additional Declarations

Supplementary Files

Status:

Version 1