Original ArticleTarget Embolization of Associated Aneurysms in Ruptured Arteriovenous Malformations
Introduction
Intracranial hemorrhage (ICH) secondary to brain arteriovenous malformations (BAVMs) carries significant morbidity and mortality.1, 2 Initial hemorrhage presentation is the most important indicator for subsequent hemorrhage for BAVM patients. The overall yearly hemorrhage risk of ruptured BAVMs ranges from 2.55%–17.8%, higher than that (2.1%–4.12%) of unruptured BAVMs.3, 4, 5, 6 Aneurysms associated with BAVMs portend a high risk of hemorrhage or rehemorrhage. The risk of hemorrhage in BAVM patients with associated aneurysms was reported to be 7% per year, which is higher than the 3% risk of hemorrhage for patients without aneurysms.3, 7, 8 Studies have proved that target embolization of associated aneurysms may decrease the hemorrhage rate and improve clinical outcome for unruptured BAVMs.9 However, for ruptured BAVMs, whether target embolization of associated aneurysms will be safe and efficient is not well known. In order to evaluate the safety and efficacy of target embolization, we compared the complication incidence rate and rehemorrhage incidence rate between ruptured BAVMs with and without associated aneurysms.
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Patients
This study was approved by the ethics committee of Beijing Tiantan Hospital. All patients signed informed consent. A series of 336 consecutive BAVM patients from January 2011 to December 2015 at Beijng Tiantan Hospital were retrospectively reviewed. Patients who presented with intracerebral hemorrhage (ICH) caused by BAVM or associated aneurysms and underwent endovascular embolization were included. Patients who underwent surgery resection before or after embolization were excluded.
ICH is
Statistical Analysis
All statistical analyses were conducted by using SPSS 18.0 (Chicago, IL, USA). Patients' characteristics were described with frequencies for categorical variables and mean ± standard deviation for continuous variables. Categorical variables were compared using Fisher exact test or the Pearson χ2 test. Continuous variables were compared between groups using student's t test. Univariate and multivariate logistic analyses were done to assess risk factors of complications. P < 0.05 was considered
Demographic and Angiographic Characteristics
A total of 129 (male = 53, 41.1%) patients met the inclusion criteria (Table 1). Age ranged from 5–65 years old (mean ± standard deviation: 26.9 ± 13.3 years old). The period of time from initial hemorrhage presentation to endovascular treatment ranged from 1–160 days (median = 42 days). The location of BAVM is cortical in 70 (54.3%) patients, deep in 40 (31.0%), infratentorial in 19 (14.7%), and eloquent in 59 (45.7%) patients. As for the maximum diameter of the nidus, 87 (67.4%) patients are
Endovascular Treatment
During the treatment period, 129 patients underwent a total of 166 (1.29 ± 0.5 sessions per patient) embolization sessions, 95 (73.6%) patients underwent 1 session, 31 (24.0%) underwent 2 sessions, and 3 (2.3%) underwent 3 or more sessions. A total of 208 pedicles (1.6 ± 0.8 pedicles per patient) were embolized. Twenty-nine (93.5%) aneurysms were occluded (Figure 2). Two were not embolized because of inaccessibility of microcatheters. Two patients were treated for associated aneurysm with coils
Complications
Thirteen complications (10.1% of patients, 7.8% per session) occurred in this series. Of the 13 patients, 2 were hemorrhagic and 11 were ischemic (Table 2). Of the 11 (8.5% per patient, 6.6% per session) ischemic complications, 8 (6.2% per patient, 4.8% per session) were transient and 3 (2.3% per patient, 1.8% per session) were permanent. Complications are not statistically significant (P > 0.05) between the AN group and non-AN group.
Risks Factors Related to Complications
In univariate and multivariate analysis (Table 3), there was a higher rate of procedural complications in BAVMs with 3 or more pedicles occluded at 1 session (P = 0.037, odds ratio = 2.798, 95% confidence interval = 1.304–6.002). A coexisting aneurysm is not an indicator of procedural complications.
Follow-Up
Outcomes were recorded through in-person (25 patients, 22.1%) or structured telephone interviews (88 patients, 77.9%). The follow-up period ranges from 1–5 years. A total of 290 (mean = 3.4) person-years' follow-up were completed for non-AN group and 99 (mean = 3.7) person-years for AN-group (total 389 person-years, mean = 3.4). Sixteen (12.4%) patients are failed to show at follow-up, including 12 (12.2%) patients in the AN group and 4 (12.9%) in the non-AN group, leaving 113 to be calculated
Clinical Outcomes
In all, 10 (annual hemorrhage rate: 10/290 = 0.034) patients in the non-AN group and 2 (annual hemorrhage rate: 2/99 = 0.020) patients in the AN group experienced postoperative hemorrhage. The overall annual hemorrhage rate after embolization was 3.1% (12/389 = 0.031). Excellent or good outcomes (mRS = 0–2) were observed in 103 (91.2%) patients. Seven (6.2%) had persistent moderate (mRS = 3) deficits, 2 had a significant deficit (1.8%, mRS > 3) due to hemorrhage, and 1 patient (0.9%) died of
Discussion
Several previous studies have reported that the endovascular procedural-related complication rate is 0%–18% and the mortality rate is 0%–4%.11, 12, 13, 14, 15, 16, 17 Clinical complications include hemorrhagic and ischemic events. The hemorrhagic complication rate after BAVM embolization was reported to be approximately 3%–15% per patient and 1%–2% per procedure.11, 18, 19 Hemorrhagic complications may be caused by vessel perforation during catheterization, BAVM rupture, intranidal aneurysm
Conclusions
Target embolization of aneurysms associated with ruptured BAVMs could significantly decrease the rehemorrhage incidence rate without increasing the complication rate.
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Conflict of interest statement: This work was supported by the Beijing Municipal Health Bureau, Special Research Project of Capital Health Development, China (grant 2016-1-1075). The authors declare they have no conflict of interests.
Yong Sun and Hengwei Jin contributed equally to this work.