Effect of functional MRI–guided navigation on surgical outcomes: a prospective controlled trial in patients with arteriovenous malformations

Abstract

OBJECTIVE The impact of functional MRI (fMRI)-guided navigation on the surgical outcome of patients with arteriovenous malformations (AVMs) is undetermined. This large, randomized controlled trial (RCT) was designed to determine the safety and efficacy of fMRI-guided microsurgery of AVMs. This paper reports the preliminary results of the interim analysis. METHODS Between September 2012 and June 2015, eligible patients were randomized to the standard microsurgery group (control group) or the fMRI-guided surgery group (experimental group) in a 1:1 ratio. Patients in the control group underwent conventional digital subtraction angiography and MRI before surgery. The surgery was performed according to the standard procedure. However, patients in the experimental group underwent blood oxygen level-dependent (BOLD) fMRI and diffusion tensor imaging within 1 week before surgery. Moreover, preoperative eloquent brain tissue mapping and intraoperative fMRI navigation were performed in addition to the standard procedure. The preliminary end points were the total removal rate of AVMs and postoperative surgical complications. The primary end points were modified Rankin Scale (mRS) score (favorable: mRS Score 0-2; poor: mRS Score 3-6) and surgery-related permanent functional deficits (S-PFD) at the last clinic visit (≥ 6 months). Statistical analysis was performed using the statistical package from SPSS. RESULTS The interim analysis included 184 participants (93 in the experimental group and 91 in the control group). Patients were equally distributed between the 2 groups. Neither the preliminary nor the primary end points, including postoperative complications (p = 0.781), residual AVM (p = 1.000), last mRS score (p = 0.654), and S-PFD (p = 0.944) showed any significant difference between the control and experimental group. According to the results of the univariate analysis, eloquent adjacent brain tissue (OR 0.14; 95% CI 0.06-0.32; p < 0.001), large size of the nidus (OR 1.05; 95% CI 1.02-1.08; p = 0.002), or diffuse nidus (OR 3.05; 95% CI 1.42-6.58; p = 0.004) were all significantly associated with S-PFD. Additionally, a high Spetzler-Martin score (OR 3.54; 95% CI 2.08-6.02; p < 0.001), no previous hemorrhage (OR 2.35; 95% CI 1.00-5.54; p = 0.05), or a low preoperative mRS score (OR 0.42; 95% CI 0.17-1.00; p = 0.049) were also significantly associated with S-PFD. Multivariate analysis revealed that independent factors correlated with S-PFD were eloquent adjacent brain tissue (OR 0.17; 95% CI 0.04-0.70; p = 0.014) and low preoperative mRS score (OR 0.22; 95% CI 0.07-0.69; p = 0.009). CONCLUSIONS This preplanned interim analysis revealed no significant differences in the primary end points between the experimental and control group, prompting an early termination of this RCT. The preliminary data indicated that the additional intervention of fMRI navigation is not associated with a more favorable surgical outcome in patients with AVMs. The results indicated that eloquent adjacent brain tissue and a low preoperative mRS score...

New predictive model for microsurgical outcome of intracranial arteriovenous malformations: study protocol

“…The three-dimensional (3D) model of the eloquent cortex (motor, language or visual), the fibre tracking of the eloquent fibres (corticospinal tract, the arcuate fasciculus or the optic radiation) and the 3D anatomic structure of the AVMs were or will be reconstructed as described in our previous publications. 26–28 32 33 …”

“…After craniotomy, the feeding arteries, AVM nidus and draining veins of the AVM as well as adjacent eloquent cortex or eloquent fibres were or will be identified with the navigator's probe, as described in our previous publications. 29 32 …”

“…Motor evoked potential and somatosensory evoked potential were or will be provided as needed for intraoperative monitoring. 29 32 …”

Classification of brain arteriovenous malformations located in motor-related areas based on location and anterior choroidal artery feeding

“…Sagittal T1-weighted anatomical MR images, time-of-flight (TOF) MRA and DT images were obtained using a 3.0 T MR scanner (SIEMENS Trio) as previously reported. 11 The acquired image data were analysed on the iPlan cranial 3.0 workstation (Brainlab). Image co-registration and fusion were performed using an automatic rigid registration.…”

Challenges and techniques for presurgical brain mapping with functional MRI

“…In ischemic cerebrovascular disease, hypoperfused vascular territories exhibit diminished cerebrovascular reserve with a ceiling effect that decreases the BOLD response ( Carusone et al, 2002 ). AVMs can generate flow gradients and regions of hypervascularization that can interfere with the BOLD signal ( Lin et al, 2016 ). Therefore, it is important to take into account of these factors when interpreting fMRI results for these patients.…”