Surgical management outcomes of intracranial arteriovenous malformations after preoperative embolization: a systematic review and meta-analysis

OBJECTIVE

Preoperative embolization for brain arteriovenous malformations (AVMs) has been shown to mitigate morbidity for high-risk AVMs, chiefly by reducing lesional blood flow before resection. However, associated risks include postembolization AVM rupture, and the effect of preoperative embolization on outcome remains uncertain. We performed a meta-analysis of the literature on preoperative embolization for microsurgically treated AVMs.

METHODS

A systematic review and meta-analysis were conducted of all English-language publications reporting clinical outcomes after combined embolization and surgical resection for AVMs. Single- and 2-arm analyses were performed using random-effects modeling.

RESULTS

Thirty-six studies with 2108 patients were included in this analysis. Most patients (90.6%) who underwent embolization had at least a 50% obliteration of AVMs on posttreatment preoperative angiography, with a mean rate of obliteration of approximately 80% (range 28.8-100%). Among patients who had combined treatment, 3.4% (95% confidence interval [CI] 2.1-4.6%) experienced embolization-related hemorrhagic complications before surgery. Both treatment groups achieved excellent postsurgical complete resection rates (odds ratio [OR] 1.05; 95% CI 0.60-1.85). Neither the clinical outcome (OR 1.42; 95% CI 0.84-2.40) nor the total number of hemorrhagic complications (OR 1.84; 95% CI 0.88-3.85) was significantly different between the treatment groups.

CONCLUSIONS

In this meta-analysis, preoperative embolization appears to have substantially reduced the lesional volume with active AV shunting before AVM resection. Anecdotally, preoperative embolization facilitates safe and efficient resection; however, differences in outcomes were not significant. The decision to pursue preoperative embolization remains a nuanced decision based on individual lesion anatomy and treatment team experience.

Transvenous embolization of hemorrhagic brain arteriovenous malformations: Case reports and literature review

Introduction

Transvenous embolization (TVE) has been proven to be safe and feasible as an alternative management of brain arteriovenous malformations (AVMs). We presented four patients with a hemorrhagic brain AVM who underwent TVE and reviewed the relevant literature.

Methods

Four patients underwent TVE of a hemorrhagic brain AVM in our center between July 2019 and July 2020. We retrospectively collected and analyzed the clinical and imaging data of these patients and those reported in previously published studies.

Results

Four patients with a hemorrhagic brain AVM were included. Nidus sizes ranged from 0.79 to 2.56 cm. Spetzler-Martin grade ranged from grade II to grade III. The AVM nidus was located in a deep brain region in three patients. One patient underwent TVE alone and three underwent combined transarterial and transvenous approaches. Digital subtraction angiography (DSA) demonstrated complete obliteration of the vascular malformation after embolization in all four patients. Three patients were independent [modified Rankin Scale (mRS) score ≤ 2] at discharge. All four patients were independent at the last follow-up. AVM obliteration was confirmed in all four patients at the last angiographic follow-up.

Conclusion

Transvenous embolization can be used as an alternative treatment for contemporary management of brain AVMs, appropriate patient selection is essential to achieve a good clinical outcome.

[Combination treatment of cerebral arteriovenous malformations using endovascular and microsurgical techniques]

MATERIAL AND METHODS

The study included 40 patients with cerebral AVMs. In the study group, 14 (35%) patients underwent microsurgical resection without preliminary embolization (1st group), and 26 (65%) patients underwent combined treatment (endovascular embolization and microsurgical intervention, 2nd group). The first group included patients with S&M grade I-III AVMs, and the second group included patients with S&M grade II-V AVMs. Treatment outcomes were evaluated with allowance for completeness of AVM resection, operative blood loss, duration of surgery, changes in clinical and neurological impairments according to the modified Rankin scale, and rate of neurological and surgical complications.

RESULTS

According to postoperative findings, AVMs were totally resected in all patients. Persistent focal neurological symptoms developed in 2 (7.7%) cases in the second group; neurological complications occurred in 1 (7.1%) patient in the first group. The mean blood loss during resection of AVMs without preliminary embolization and embolized AVMs in patients with S&M grade I-III AVMs was 271.4 mL and 149.1 mL, respectively. The duration of surgery and blood loss did not differ significantly in microsurgery and combination treatment groups.

CONCLUSION

Combination treatment, including microsurgical intervention after endovascular embolization, is an effective treatment for AVMs, in particular for high grade (S&M grade III-V) AVMs. Teamwork and coordination among the surgeon, endovascular surgeon, and radiologist in treatment of AVMs is a prerequisite for a good outcome.