Selective occlusion of splenic artery aneurysms with the coil packing technique: the impact of packing density on aneurysm reperfusion correlated between contrast-enhanced MR angiography and digital subtraction angiography.

Abstract

The aim was to evaluate the relationship between coil packing densities after splenic artery aneurysm (SAA) treatment using detachable microcoils and rates of SAA reperfusion and to suggest a post-treatment surveillance protocol using contrast-enhanced MRA. Evaluated were 16 patients (4 men; mean age 46.7), who underwent true SAA embolization using detachable microcoils (Concerto, Medtronic). SAAs were treated by selective coil packing (CP) or stent-assisted coil exclusion (SAC). Contrast-enhanced magnetic resonance angiography (CE-MRA) and digital subtraction angiography (DSA) were performed at 3months post-procedure and correlated. Primary CP was used in 13 patients, while SAC was used in three patients. On follow-up, complete aneurysm occlusion was seen in seven patients (43.8%). Sac reperfusion occurred in nine patients (56.2%) and was demonstrated in all CE-MRA and six DSA studies. Mean aneurysm packing density was 20.10 ± 8.05% for the CP group and 32.90 ± 11.95% for the SAC group (p = 0.038). There was a significant difference in the incidence of aneurysm sac reperfusion on CE-MRA study between CP and SAC (9 vs. 0). No sac reperfusion was seen in aneurysms with packing densities ≥ 29%, irrespective of either embolization method. Favorable midterm results for coil packing of SAAs seem to depend on the coil packing density with a coil volume approximately a quarter of the aneurysm volume being most effective. Follow-up should involve the use of CE-MRA as this modality has been shown to be superior over DSA in detecting aneurysm reperfusion and coil compaction. Level IV, therapeutic study.