Preoperative embolisation of brain arteriovenous malformations: a systematic review and meta-analysis

Abstract

Preoperative embolisation is a commonly performed adjunct to microsurgical excision of brain arteriovenous malformations (bAVMs), with aims such as lessening the technical difficulty of the microsurgical procedure, reducing operative time, decreasing blood loss, and improving patient functional outcomes. We aim to perform a systematic review of randomised trials and cohort studies evaluating preoperative embolisation of bAVMs published between 01 January 2000 and 31 March 2021 and appraise its role in clinical practice. A MEDLINE search was performed, and articles reporting on outcomes following preoperative embolisation, as an adjunct to microsurgery, were eligible for inclusion. PRISMA reporting and Cochrane Handbook guidelines were followed. The primary outcome measure was the risk of complications associated with preoperative embolisation. The study was registered with PROSPERO (CRD42021244231). Of the 1661 citations, 8 studies with 588 patients met predefined inclusion criteria. No studies specifically compared outcomes of surgical excision of bAVMs between those with and without preoperative embolisation. Spetzler Martin (SM) grading was available in 301 cases. 123 of 298 (41⋅28%) patients presented with haemorrhage. Complications related to embolisation occurred in 175/588 patients (29.4%, 95% CI 19.6–40.2). Permanent neurological deficits occurred in 36/541 (6%, 95% CI 3.9–8.5) and mortality in 6/588 (0.41%, 95% CI 0–1.4). This is the first systematic review evaluating preoperative embolisation of bAVMs. Existing studies assessing this intervention are of poor quality. Associated complication rates are significant. Based on published literature, there is currently insufficient evidence to recommend preoperative embolisation of AVMs. Further studies are required to ascertain if there are benefits of this procedure and if so, in which cases.

State of the Art in the Role of Endovascular Embolization in the Management of Brain Arteriovenous Malformations—A Systematic Review

“…This technique involves the formation of a plug around the tip of the catheter to establish and increase a pressure gradient to the distal part within the nidus, thus stimulating the forward penetration of the embolization agent [ 105 , 106 ]. Nonetheless, due to the difficulty of controlling the level of reflux and the possible risk of occluding nontarget arteries, Chapot’s transarterial pressure cooker technique (PCT), transarterial balloon-assisted embolization, and transvenous embolization ( Figure 2 ) have been proposed as alternatives to successfully reduce copolymer reflux and mitigate the risk of ischemic stroke or hemorrhages [ 105 , 106 , 107 , 108 ]. Likewise, Cekrige et al recommended their multiplug flow-control technique to effectively control or arrest the flow during injection of a liquid embolic agent.…”

Comparison of conservative management, microsurgery only, and microsurgery with preoperative embolization for unruptured arteriovenous malformations: A propensity score weighted prospective cohort study

“…suggested that unruptured AVMs were less likely to benefit from the interventional treatment 33 . In addition to the patient selection, a systematic review also criticized that most studies evaluating treatment effects failed to correct for underlying confounders 8 . To the best of our knowledge, this is the first study to date comparing multiple treatment strategies in unruptured AVMs with sIPTW balancing the baseline characteristics among groups, as we aimed to provide comprehensive and robust evidence for more individualized recommendations in this post‐ARUBA era 23 …”

“…Previous studies evaluating the role of preoperative embolization focused on benefiting the surgery, which can be translated into reducing blood loss, shortening operative time, and increasing obliteration rates 8,31,34,35 . However, many researchers suggested contradicting findings, and they proposed that making surgery easier may not make the overall management safer 36 .…”

“…33 In addition to the patient selection, a systematic review also criticized that most studies evaluating treatment effects failed to correct for underlying confounders. 8 To the best of our knowledge, this is the first study to date comparing multiple treatment strategies in unruptured AVMs with sIPTW balancing the baseline characteristics among groups, as we aimed to provide comprehensive and robust evidence for more individualized recommendations in this post-ARUBA era. 23 This study demonstrated that patients receiving CM could experience less disability and neurological deterioration, which was in accordance with the neurofunctional impairment analysis of the ARUBA trial.…”

Brain arteriovenous malformations of the middle cerebral artery region: image characteristics and endovascular treatment based on a new classification system

“…Currently, treatment options for BAVMs include endovascular treatment (EVT), surgical resection, radiotherapy, and medical therapy [8]. Of these options, EVT has an important role in the curative embolization of low-grade BAVMs or the adjunctive embolization of high-grade BAVMs in reducing the risk of surgery and radiosurgery [9][10][11].…”