Feasibility of intraoperative MRI for endovascular coiling of intracranial aneurysms: A single centre experience

Abstract

Background: Intraoperative magnetic resonance imaging system (iMRIS) surgical theatre is a highly integrated operating room with an intraoperative magnetic resonance imaging (iMRI) designed originally for brain tumour surgery. Its use in neurointerventional procedures, particularly in the setting of endovascular coiling of intracranial aneurysms, has not been discussed in the literature to date. We present our initial experience about the safety and feasibility of iMRI to assess post operative complications and provide baseline imaging post coiling of intracranial aneurysms.

Methods: Consecutive patients who underwent iMRI between 2015 and 2018 were included in the study. Demographic, clinical details, endovascular technique and surgical outcomes were collected. Details of anesthesia during the procedure were also collected.

Results: Fifteen patients underwent iMRI with MRA to assess post coiling status of their elective endovascular coiling of intracranial aneurysms. The mean age in this cohort was 61 years and 46.7% were male. No immediate complications were seen either from the endovascular procedures or from the iMRI. All iMRI scans were performed as planned with no aborted or truncated scans. The image quality of the iMRI/MRA was adequate to detect the residual aneurysm, if present. There was no residual aneurysm on the angiogram that were not detected on the iMRIs. Of the 15 patients, 10 were safely discharged the following day and other 5 were discharged 2 days after their surgery.

Conclusions: The iMRI is an advantageous tool which can be integrated into neurointerventional workflow resulting in early post peri-procedural feedback and potentially reduced post-operative hospital stay.

Keywords: IMRIS; Intraoperative MRI; interventional endovascular aneurysm repair.

Figure 1.

Recurrence of previously coiled (a) right posterior communicating artery aneurysm (arrow). Immediate post-treatment angiogram (b) showed no or minimal residual filling of the aneurysm neck (arrow). The iMRI showed small residual filling (arrow) at the neck on (c) time-of-flight MR angiogram and (d) contrast enhanced MR angiogram.

Figure 2.

Patient with coiling of (a) an anterior communicating artery aneurysm developed spasm secondary to stent placement (arrow). (b)The spasm improved with intra-arterial verapamil with focal residual spasm (arrow). (c)The residual vasospasm (arrow) was also seen on the time-of-flight MR angiogram done as part of intra-op MRI (iMRI). (d) The iMRI also showed a clinically silent left cerebellar small embolic infarct (arrow) on diffusion weighted images.