Symptomatic periprocedural intracranial hemorrhage unrelated to coil embolization in 1287 patients with intracranial aneurysms.

PURPOSE: Periprocedural symptomatic intracranial hemorrhage (sICH) unrelated to coil embolization of intracranial aneurysm has been rarely reported. The incidence and characteristics of this complication remain unclear. This study was designed to elucidate the incidence and characteristics of periprocedural sICH unrelated to coiling of intracranial aneurysm, and to explore the possible mechanisms underlying this complication.

METHODS: Included in this retrospective study were 1287 patients with 1394 aneurysms who were treated with coil embolization (476 patients with stent assistance and 811 patients without stents) between May 2008 and August 2017. All procedure-unrelated sICHs that occurred within 30 days after coiling were selected. The technical details of the procedure, clinical characteristics, and medical therapy were recorded.

RESULTS: A total of 6 patients developed periprocedural sICH unrelated to coil embolization. All these six patients underwent stent-assisted coiling (SAC). Therefore, there was a 1.3% (6/476) procedure-unrelated sICH rate of SAC and 0% (0/811) in patients underwent coiling without stent during the periprocedural period (P = 0.005, RR 0.987; 95% CI, 0.977-0.997). These phenomena occurred more often in patients who received SAC for ruptured aneurysms vs patients underwent this technique for unruptured aneurysms (2.0 vs 0.7%, P = 0.390, RR 2.896; 95% CI, 0.525-15.968). All these phenomena occurred within 7 days after coiling, and resulted in one mortality, one unfavorable outcome (mRS Score 3), and other four favorable outcomes (mRS Scores 0-2) at 90 days after procedure.

CONCLUSION: Our findings suggest that the procedure-unrelated sICH, though less frequent, may exist following stent-assisted coiling of intracranial aneurysm during the periprocedural period. Extra caution may be warranted in patients who were treated with SAC for ruptured aneurysms.