Clinical and Radiological Outcomes of Intracranial Aneurysm Clipping Aided by Transit Time Flowmetry

Rick H. G. J. Van Lanen*, Linda A. A. Jacobi-Postma, Tim J. Veersema, Onno P. M. Teernstra, Jim T. A. Dings

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


BACKGROUND: Since the International Subarachnoid Aneurysm Trial, coiling has been favored over clipping for intracranial aneurysms, resulting in selection of increasingly complex aneurysm configurations for clipping. We present the outcomes of clipping of aneurysms not suitable for coiling, with transit time flowmetry technology to aid monitoring of intraoperative flow.

METHODS: All consecutive patients surgically treated for intracranial aneurysms were included. We assessed intraoperative arterial blood flow in relation to postoperative ischemia and unfavorable outcome (modified Rankin Scale score 3-6), along with radiological occlusion rate, at 6 months and 1 year after surgery.

RESULTS: Mortality at 1 year was 7.9%, with a 21.6% rate of an unfavorable outcome. Almost all (96.1%) of patients with unruptured aneurysms had an favorable outcome at 1 year, compared with 71.9% of patients with aneurysmal subarachnoid hemorrhage. Postoperative computed tomography imaging showed an 86.7% occlusion rate and a 7.5% rate of clip-related ischemia. Flow 50% above baseline flow in 85.7% of aneurysms. Less than 50% flow from baseline was an independent predictor of unfavorable outcome (OR, 3.85; 95% CI, 1.6-9.0; P = 0.001), along other risk factors.

CONCLUSION: In this study of clinical and radiological outcomes of surgically treated cerebral aneurysms not suitable for unassisted coiling, we showed positive results for these challenging aneurysms, aided by transit time flowmetry as a valuable tool, providingquantitative measurements of arterial blood flow to help achieve optimal clip placement and minimizing aneurysm residuals that may be sites of rebleeding. Adequate flow, defined as >= 50% of baseline, greatly reduces the risk of unfavorable outcome.

Original languageEnglish
Pages (from-to)E660-E670
Number of pages11
JournalWorld Neurosurgery
Publication statusPublished - Apr 2020


  • Aneurysm clipping
  • Aneurysm residuals
  • Flow probe
  • Functional outcome
  • Occlusion
  • Transit time flowmetry
  • RISK
  • ISAT

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