"Mass Reduction" Clipping Technique for Large and Complex Intracranial Middle Cerebral Artery Aneurysm.

BACKGROUND: Treatment of complex unruptured middle cerebral artery (MCA) aneurysms that are untreatable with conventional surgical techniques are rare, and direct aneurysmal clipping usually remains the first-line treatment for large and giant saccular MCA aneurysms. Tandem clipping and multiple clipping techniques represent neck reconstruction in direct clipping surgeries that address these aneurysms.

CASE DESCRIPTION: The authors describe a simple variation of neck reconstructive clipping techniques for the large MCA unruptured aneurysm in a patient with an unruptured 20-mm MCA bifurcation aneurysm. The key of this technique is the application of an appropriate initial clip, the "mass reduction clip"; this clip is inserted not into the aneurysmal neck but on the center of the aneurysmal dome so as to compress the dome at first, which yields a change in the aneurysm's shape and reduces the size of the whole aneurysmal mass. This technique facilitates the ensuing neck reconstruction according to the concept of the ideal closure line using few clips.

CONCLUSIONS: "Mass reduction" clipping, which changes the shape of the aneurysm and reduces the size of the whole aneurysmal mass, is a useful variation for the treatment of large aneurysms when conventional clipping across the neck is feasible.