Concept of ideal closure line for clipping of middle cerebral artery aneurysms--technical note.

The concept of optimum closure line was applied to a series of 51 consecutive middle cerebral artery aneurysms (14 ruptured, 37 unruptured) in 41 patients, 16 men and 25 women aged 29-79 years (mean 59.1 years). Visual inspection through the operating microscope revealed 3 types of aneurysm based on the origin of the aneurysm: bifurcation type (n = 39), trunk type (n = 9), and combined type (n = 3). Clipping along the optimum closure line should restore the vascular structure to the original configuration. Combination clip techniques were useful to form a curved closure line. This technique requires adequate operative fields with dissection of the aneurysm and related arteries from the neighboring structures as far as possible. The closure line concept is helpful to decide how to apply clips for particular aneurysms to avoid risks of ischemic complication and future recurrence. Combination clip techniques are often necessary to match a curved closure line.