Pitfall of Intraoperative Microvascular Doppler Sonography for Confirming the Complete Occlusion of Aneurysm

Hong, Ji Myoung; Kang, Sung Don; Kim, Jong Moon

Abstract

OBJECTIVE
It is mandatory to optimaze clip placement in situ for complete clipping of cerebral aneurysm. Intraoperative microvascular doppler sonography (MDS) provides a functional and non-invasive intraoperative examination of the aneurysm proper. The present study was performed to investigate the reliability of MDS for assessing the complete aneurysm closure.
METHODS
Blood flow velocities in the aneurysm sac were determined by MDS with a 20-MHz probe before and after aneurysm clipping, to confirm the obliteration of aneurysm since 1997. Complete aneurysm obliteration was confirmed by absent flow patterns in the domes of all aneurysms after clipping.
RESULTS
The 1 mm microprobe was able to insonate all vessels and their major branches. The immediate adjustment of aneurysm clip placement or another clipping was done because hemorrhage after puncturing of completely clipped aneurysms on MDS developed in five patients including 3 middle cerebral artery aneurysms, 1 posterior communicating artery aneurysm, and 1 anterior communicating artery aneurysm.
CONCLUSIONS
MDS is safe and cost-efficient for evaluation of aneurysm obliteration. In many cases, it can preclude the need of postoperative angiogram. However, although an intra-aneurysmal flow velocity is absent on MDS, it is necessary to puncture or cut the aneurysm sac if that is not shrunken after clipping, especially in cases of a complex aneurysm with a broad irregular base and atherosclerotic or thrombotic sac.