European Radiology

, Volume 25, Issue 2, pp 428–435 | Cite as

Cerebral aneurysm treatment using flow-diverting stents: in-vivo visualization of flow alterations by parametric colour coding to predict aneurysmal occlusion: preliminary results

  • Philipp GölitzEmail author
  • Tobias Struffert
  • Julie Rösch
  • Oliver Ganslandt
  • Frauke Knossalla
  • Arnd Doerfler



After deployment of flow-diverting stents (FDS), complete aneurysm occlusion is not predictable. This study investigated whether parametric colour coding (PCC) could allow in vivo visualization of flow alterations induced by FDS and identify favourable or adverse flow modulations.


Thirty-six patients treated by FDS were analyzed. Preinterventional and postinterventional DSA-series were postprocessed by PCC and time-density curves (TDCs) were calculated. The parameters aneurysmal inflow, outflow, and relative time-to-peak (rTTP) were calculated. Preinterventional and postinterventional values were compared and related to occlusion rate.


Postinterventional inflow showed a mean reduction of 37 %, outflow of 51 %, and rTTP a prolongation of 82 %. Saccular aneurysm occlusion occurred if a reduction of at least 15 % was achieved for inflow and 35 % for outflow (sensitivity: 89 %, specificity: 82 %). Unchanged outflow and a slightly prolonged rTTP were associated with growth in one fusiform aneurysm.


PCC allows visualization of flow alterations after FDS treatment, illustrating “flow diverting effects” by the TDC shape and indicating mainly aneurysmal outflow and lesser inflow changes. Quantifiable parameters (inflow, outflow, rTTP) can be obtained, thresholds for predicting aneurysm occlusion determined, and adverse flow modulations assumed. As a rapid intraprocedural tool, PCC might support the decision to implant more than one FDS.

Key Points

After deployment of a flow-diverting stent, complete aneurysm occlusion is unpredictable.

Parametric colour coding offers new options for visualizing in vivo flow alterations non-invasively.

Quantifiable parameters, i.e., aneurysmal inflow/outflow can be obtained allowing prognostic stratification.

Rapid, intraprocedural application allows treatment monitoring, potentially contributing to patient safety.


Flow-diverting stent Time-density curve Digital subtraction angiography Image postprocessing Aneurysms 



Digital subtraction angiography


Flow-diverting stent


Internal carotid artery


Parametric colour coding


Relative time-to-peak




Time-density curve



The scientific guarantor of this publication is Philipp Gölitz, MD. The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article. The authors state that this work has received funding of the Medical Valley national leading edge cluster, Erlangen, Germany, diagnostic imaging network, sub-project BD 16, research grant nr. 13EX1212G and sub-project BD 20, research grant nr. 13G 0031A. No complex statistical methods were necessary for this paper. Institutional Review Board approval was obtained. Written informed consent was obtained from all subjects (patients) in this study. Methodology: prospective, diagnostic or prognostic study, performed at one institution.


  1. 1.
    Fischer S, Vajda Z, Aguilar Perez M et al (2012) Pipeline embolization device (PED) for neurovascular reconstruction: initial experience in the treatment of 101 intracranial aneurysms and dissections. Neuroradiology 54:369–382PubMedCentralPubMedCrossRefGoogle Scholar
  2. 2.
    McAuliffe W, Wycoco V, Rice H, Phatouros C, Singh TJ, Wenderoth J (2012) Immediate and midterm results following treatment of unruptured intracranial aneurysms with the pipeline embolization device. AJNR Am J Neuroradiol 33:164–170PubMedCrossRefGoogle Scholar
  3. 3.
    Lubicz B, Collignon L, Raphaeli G, De Witte O (2011) Pipeline flow diverter stent for endovascular treatment of intracranial aneurysms: preliminary experience in 20 patients with 27 aneurysms. World Neurosurg 76:114–119PubMedCrossRefGoogle Scholar
  4. 4.
    Szikora I, Berentei Z, Kulcsar Z et al (2010) Treatment of intracranial aneurysms by functional reconstruction of the parent artery: the Budapest experience with the Pipeline embolization device. AJNR Am J Neuroradiol 31:1139–1147PubMedCrossRefGoogle Scholar
  5. 5.
    Nelson PK, Lylyk P, Szikora I, Wetzel SG, Wanke I, Fiorella D (2011) The Pipeline embolization device for the intracranial treatment of aneurysms trial. AJNR Am J Neuroradiol 32:34–40PubMedCrossRefGoogle Scholar
  6. 6.
    Kulcsar Z, Houdart E, Bonafe A et al (2011) Intra-aneurysmal thrombosis as a possible cause of delayed aneurysm rupture after flow-diversion treatment. AJNR Am J Neuroradiol 32:20–25PubMedGoogle Scholar
  7. 7.
    McAuliffe W, Wenderoth JD (2012) Immediate and midterm results following treatment of recently ruptured intracranial aneurysms with the Pipeline embolization device. AJNR Am J Neuroradiol 33:487–493PubMedCrossRefGoogle Scholar
  8. 8.
    Turowski B, Macht S, Kulcsár Z, Hänggi D, Stummer W (2011) Early fatal hemorrhage after endovascular cerebral aneurysm treatment with a flow diverter (SILK-Stent): do we need to rethink our concepts? Neuroradiology 53:37–41PubMedCrossRefGoogle Scholar
  9. 9.
    Hampton T, Walsh D, Tolias C et al (2011) Mural destabilization after aneurysm treatment with a flow-diverting device: a report of two cases. J Neurointerv Surg 3:167–171PubMedCrossRefGoogle Scholar
  10. 10.
    Briganti F, Napoli M, Tortora F et al (2012) Italian multicenter experience with flow-diverter devices for intracranial unruptured aneurysm treatment with periprocedural complications-a retrospective data analysis. Neuroradiology 54:1145–1152PubMedCrossRefGoogle Scholar
  11. 11.
    Velat GJ, Fargen KM, Lawson MF, Hoh BL, Fiorella D, Mocco J (2012) Delayed intraparenchymal haemorrhage following pipeline embolization device treatment for a giant recanalized ophthalmic aneurysm. J Neurointerv Surg 4:e24PubMedCrossRefGoogle Scholar
  12. 12.
    Cebral JR, Mut F, Raschi M et al (2011) Aneurysm rupture following treatment with flow-diverting stents: computational hemodynamics analysis of treatment. AJNR Am J Neuroradiol 32:27–33PubMedGoogle Scholar
  13. 13.
    Hassan T, Ahmed YM, Hassan AA (2011) The adverse effects of flow-diverter stent-like devices on the flow pattern of saccular intracranial aneurysm models: computational fluid dynamics study. Acta Neurochir 153:1633–1640PubMedCrossRefGoogle Scholar
  14. 14.
    Seshadhri S, Janiga G, Beuing O, Skalej M, Thevenin D (2011) Impact of stents and flow diverters on hemodynamics in idealized aneurysm models. J Biomech Eng 133:071005PubMedCrossRefGoogle Scholar
  15. 15.
    Strother CM, Bender F, Deuerling-Zheng Y et al (2010) Parametric color coding of digital subtraction angiography. AJNR Am J Neuroradiol 31:919–924PubMedCrossRefGoogle Scholar
  16. 16.
    Struffert T, Deuerling-Zheng Y, Engelhorn et al (2013) Monitoring of ballon test occlusion of the internal carotid artery by parametric color coding and perfusion imaging within the angio suite: first results. Clin Neuroradiol 23:285–292PubMedCrossRefGoogle Scholar
  17. 17.
    Fargen KM, Velat GJ, Lawson MF, Mocco J, Hoh BL (2012) Review of reported complications associated with the Pipeline Embolization Device. World Neurosurg 77:403–404PubMedCrossRefGoogle Scholar
  18. 18.
    Cebral JR, Mut F, Weir J, Putman C (2011) Quantitative characterization of the hemodynamic environment in ruptured and unruptured brain aneurysms. AJNR Am J Neuroradiol 32:145–151PubMedCentralPubMedCrossRefGoogle Scholar
  19. 19.
    Dorn F, Niedermeyer F, Balasso A, Liepsch D, Liebig T (2011) The effect of stents on intra-aneurysmal hemodynamics: in vitro evaluation of a pulsatile sidewall aneurysm using laser Doppler anemometry. Neuroradiology 53:267–272PubMedCrossRefGoogle Scholar
  20. 20.
    Trager AL, Sadasivan C, Seong J, Lieber BB (2009) Correlation between angiographic and particle image velocimetry quantifications of flow diverters in an in vitro model of elastase-induced rabbit aneurysms. J Biomech Eng 131:034506PubMedCentralPubMedCrossRefGoogle Scholar
  21. 21.
    Sadasivan C, Cesar L, Seong, Wakhloo AK, Lieber BB (2009) Treatment of rabbit elastase-induced aneurysm models by flow diverters: development of quantifiable indexes of device performance using digital subtraction angiography. IEEE Trans Med Imaging 28:1117–1125PubMedCentralPubMedCrossRefGoogle Scholar
  22. 22.
    Struffert T, Ott S, Kowarschik M et al (2013) Measurement of quantifiable parameters by time-density curves in the elastase-induced aneurysm model: first results in the comparison of a flow diverter and a conventional aneurysm stent. Eur Radiol 23:521–527PubMedCrossRefGoogle Scholar
  23. 23.
    O'kelly CJ, Krings T, Fiorella D, Marotta TR (2010) A novel grading scale for the angiographic assessment of intracranial aneurysms treated using flow diverting stents. Interv Neuroradiol 16:133–137PubMedCentralPubMedGoogle Scholar
  24. 24.
    Kamran M, Yarnold J, Grunwald IQ, Byrne JV (2011) Assessment of angiographic outcomes after flow diversion treatment of intracranial aneurysms: a new grading schema. Neuroradiology 53:501–508PubMedCrossRefGoogle Scholar
  25. 25.
    De Barros Faria M, Castro RN, Lundquist J et al (2011) The role of the pipeline embolization device for the treatment of dissecting intracranial aneurysms. AJNR Am J Neuroradiol 32:2192–2195PubMedCrossRefGoogle Scholar
  26. 26.
    Brinjikji W, Murad MH, Lanzino G, Cloft HJ, Kallmes DF (2013) Endovascular treatment of intracranial aneurysms with flow diverters: a meta-analysis. Stroke 44:442–447PubMedCrossRefGoogle Scholar

Copyright information

© European Society of Radiology 2014

Authors and Affiliations

  • Philipp Gölitz
    • 1
    Email author
  • Tobias Struffert
    • 1
  • Julie Rösch
    • 1
  • Oliver Ganslandt
    • 2
  • Frauke Knossalla
    • 3
  • Arnd Doerfler
    • 1
  1. 1.Department of NeuroradiologyUniversity of Erlangen- NurembergErlangenGermany
  2. 2.Department of NeurosurgeryUniversity of Erlangen-NurembergErlangenGermany
  3. 3.Department of NeurologyUniversity of Erlangen- NurembergErlangenGermany

Personalised recommendations