Diagnostic yield of different imaging modalities in the detection rate of intracranial aneurysm remnants after microsurgical clipping – A systematic review and meta-analysis

Objective

While the long-term durability of completely clipped intracranial aneurysms (IA) is excellent, IA with remnants poses a significant risk for future re-growth with subsequent need for long-term follow-up or requirement for retreatment. We aim at reviewing the detection rate of IA remnants after clip ligation in the imaging modalities used to date.

Methods

A systematic review was performed according to the PRISMA guidelines using the PubMed/Medline database. The search terms included “intracranial aneurysm” AND “remnant” either in combination with “digital subtraction angiography” OR “computed tomography angiography” OR “indocyanine green video angiography”.

Results

The overall observed prevalence of IA remnants after clipping was 5.9 %, 10.9 %, 12.5 %, 14.1 % and 28.3 %, using ICG-VA, intraoperative 2D-DSA, CTA, and 3D-DSA, respectively. In studies comparing all imaging modalities altogether, 3D-DSA performed significantly better (p < 0.001) than any other single modality. The diagnostic yield of CTA and DSA gradually improved over time. Irrespective of imaging modality the percentage of IA remnants is higher in ruptured than unruptured IAs.

Conclusion

Although the diagnostic yield of CTA and 2D-DSA have substantially improved over recent years 3D-DSA provides the highest overall detection rate of clipped IA remnants. In direct comparison, 3D-DSA performs better than any other imaging modality.