Concept of Ideal Closure Line for Clipping of Middle Cerebral Artery Aneurysms -Technical Note-

Abstract

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.

Factors influencing cerebral aneurysm obliteration and reliability of indocyanine green video-angiography

“…The following clipping-related information was also collected: type of clips used (curved versus straight), number of clips applied, direction of the closure line [10] generated by the clips to the parent branching vessels, and detailed clipping methods. The relevance of findings from intraoperative ICG-V (negative, positive, or false-negative) was analyzed in terms of the aforementioned factors.…”

Ideal clipping methods for unruptured middle cerebral artery bifurcation aneurysms based on aneurysmal neck classification

“…Before clipping along the primary closure line, the question of how to close the remnant portion should be considered. In many cases, the different shapes of multiple clips enabled complete closure of MCBIF aneurysms with complex necks [2,9]. Multiple clipping offers the advantages of maintaining the normal anatomy of the blood vessels and preserving the competency of cerebral blood flow by aneurysm neck remodeling.…”

“…Although aneurysm obliteration by microsurgical clipping has been shown to have a low recurrence rate and high durability, for completeness of the procedure, the unique anatomy of the aneurysm should be considered when performing neck closure with microsurgical clips [9,12,13,29,30]. It is important to properly cover the aneurysm neck without any remnants and to preserve the normal blood flow.…”

Subarachnoid hemorrhage after surgical treatment of unruptured intracranial aneurysms

“…As described by Ishikawa et al, the closure line is considered ideal if it "restores the original vascular configuration present before the aneurysm developed" and "the maximum of the pathological wall of the aneurysm is included within the clips." 13 Aneurysm sizes were categorized as small (< 15 mm), large (15-24 mm), and giant (≥ 25 mm). The surgical technique of extracranial to intracranial high-flow bypass was described previously.…”