Partial coil embolization before surgical clipping of ruptured intracranial aneurysms

Intraoperative rupture (IOR) is the most common adverse event encountered during surgical clip obliteration of ruptured intracranial aneurysms. Besides increasing surgeon experience and early proximal control, no methods exist to decrease IOR risk. Thus, our objective was to assess if partial endovascular coil embolization to protect the aneurysm before clipping decreases IOR.

We conducted a retrospective analysis of patients with ruptured intracranial aneurysms that were treated with surgical clipping at two tertiary academic centers. We compared patient characteristics and outcomes of those who underwent partial endovascular coil embolization to protect the aneurysm before clipping to those who did not. The primary outcome was IOR. Secondary outcomes were inpatient mortality and discharge destination.

We analyzed 100 patients. Partial endovascular aneurysm protection was performed in 27 patients. Age, sex, subarachnoid hemorrhage severity, and aneurysm location were similar between the partially-embolized and non-embolized groups. The median size of the partially-embolized aneurysms was larger (7.0 mm [interquartile range 5.95-8.7] vs. 4.6 mm [3.3-6.0]; P < 0.001). During surgical clipping, IOR occurred less frequently in the partially-embolized aneurysms than non-embolized aneurysms (2/27, 7.4%, vs. 30/73, 41%; P = 0.001). Inpatient mortality was 14.8% (4/27) in patients with partially-embolized aneurysms and 28.8% (21/73) in patients without embolization (P = 0.20). Discharge to home or inpatient rehabilitation was 74.0% in patients with partially-embolized aneurysms and 56.2% in patients without embolization (P = 0.11). A complication from partial embolization occurred in 2/27 (7.4%) patients.

Preoperative partial endovascular coil embolization of ruptured aneurysms is associated with a reduced frequency of IOR during definitive treatment with surgical clip obliteration. These results and the impact of preoperative partial endovascular coil embolization on functional outcomes should be confirmed with a randomized trial.