Loop microcatheter technique for coil embolization of paraclinoid aneurysms

Abstract

Background: Although paraclinoid aneurysms do not exhibit a high risk of rupture, coil embolization is not always easy because of unstable microcatheter position. We present a technique that allows a stable microcatheter position for coil embolization of paraclinoid aneurysms.

Methods: We enrolled 34 consecutive patients who underwent coil embolization for paraclinoid aneurysms. A loop of distal microcatheter was shaped based on three-dimensional rotational angiography. The basic concept is to keep the proximal loop abutting the opposite wall of the aneurysm while using the distal loop for coiling. Then, a proximal curve was made to accommodate the shape of the carotid siphon, which may decide the direction of the loop. Stent-assisted coil embolization was performed in 19 wide-necked aneurysms. Immediate radiological outcomes were analyzed with Raymond classification and clinical outcomes were evaluated with modified Rankin Scale (mRS) scores.

Results: Satisfactory occlusion of aneurysm was achieved in 94.1% (32/34) of patients with a Raymond score of 1 or 2. Packing density of ≥ 31% was achieved in 71% (24/34) of patients. No significant differences were observed between stent-assisted coiling and coiling-only groups. Follow-up magnetic resonance angiography and/or angiogram showed stable coil position, except in one patient with tiny recurrence (from Raymond scores 1 to 2) that did not require retreatment at the 6-month follow-up. mRS scores of 0-1 were obtained in all patients at 6 months.

Conclusions: Loop microcatheter technique allowed safe and stable coil packing for paraclinoid aneurysms. The same procedural concept is also being used for aneurysms in other vascular territories.

Keywords: Aneurysm; Coiling; Embolization; Microcatheter shaping.