Skip to main content

Loop microcatheter technique for coil embolization of paraclinoid aneurysms



Although paraclinoid aneurysms do not exhibit a high risk of rupture, coil embolization is not always easy because of unstable microcatheter position. We present a technique that allows a stable microcatheter position for coil embolization of paraclinoid aneurysms.


We enrolled 34 consecutive patients who underwent coil embolization for paraclinoid aneurysms. A loop of distal microcatheter was shaped based on three-dimensional rotational angiography. The basic concept is to keep the proximal loop abutting the opposite wall of the aneurysm while using the distal loop for coiling. Then, a proximal curve was made to accommodate the shape of the carotid siphon, which may decide the direction of the loop. Stent-assisted coil embolization was performed in 19 wide-necked aneurysms. Immediate radiological outcomes were analyzed with Raymond classification and clinical outcomes were evaluated with modified Rankin Scale (mRS) scores.


Satisfactory occlusion of aneurysm was achieved in 94.1% (32/34) of patients with a Raymond score of 1 or 2. Packing density of ≥ 31% was achieved in 71% (24/34) of patients. No significant differences were observed between stent-assisted coiling and coiling-only groups. Follow-up magnetic resonance angiography and/or angiogram showed stable coil position, except in one patient with tiny recurrence (from Raymond scores 1 to 2) that did not require retreatment at the 6-month follow-up. mRS scores of 0–1 were obtained in all patients at 6 months.


Loop microcatheter technique allowed safe and stable coil packing for paraclinoid aneurysms. The same procedural concept is also being used for aneurysms in other vascular territories.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4


  1. Cho YD, Rhim JK, Park JJ, Jeon JS, Yoo RE, Kang HS, Kim JE, Cho WS, Han MH (2015) Microcatheter looping to facilitate aneurysm selection in coil embolization of Paraclinoid aneurysms. Korean J Radiol 16(4):899–905

    Article  PubMed  PubMed Central  Google Scholar 

  2. Ishibashi T, Takao H, Suzuki T, Yuki I, Kaku S, Kan I, Nishimura K, Suzuki T, Watanabe M, Karagiozov K, Murayama Y (2016) Tailor-made shaping of microcatheters using three-dimensional printed vessel models for endovascular coil embolization. Comput Biol Med 7759-63

  3. Jia ZY, Shi HB, Miyachi S, Hwang SM, Sheen JJ, Song YS, Kim JG, Lee DH, Suh DC (2018) Development of new endovascular devices for aneurysm treatment. J Stroke 20(1):46–56

    Article  PubMed  PubMed Central  Google Scholar 

  4. Juvela S, Poussa K, Lehto H, Porras M (2013) Natural history of unruptured intracranial aneurysms: a long-term follow-up study. Stroke 44(9):2414–2421

    Article  PubMed  Google Scholar 

  5. Kim SY, Park DS, Park HY, Chun YI, Moon CT, Roh HG (2017) Simple coiling versus stent-assisted coiling of Paraclinoid aneurysms: radiological outcome in a single center study. J Korean Neurosurg Soc 60(6):644–653

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  6. Kwon BJ, Im SH, Park JC, Cho YD, Kang HS, Kim JE, Han MH (2010) Shaping and navigating methods of microcatheters for endovascular treatment of paraclinoid aneurysms. Neurosurgery 67(1):34–40 discussion 40

    Article  PubMed  Google Scholar 

  7. Liu H, Park D, Hwang SM, Lee GY, Lim OK, Kim M, Lee DH, Park W, Koo H-W, Yang K, Suh DC (2016) Outpatient day-care Neuroangiography and Neurointervention of Unruptured intracranial aneurysms. Neurointervention 11(1):37–41

    Article  PubMed  PubMed Central  Google Scholar 

  8. Roy D, Milot G, Raymond J (2001) Endovascular treatment of unruptured aneurysms. Stroke 32(9):1998–2004

    Article  PubMed  CAS  Google Scholar 

  9. Sheen JJ, Suh DC (2017) Low-angled microcatheter approach for coil embolization of the anterior choroidal artery aneurysm. Neuroradiology 59(10):1053–1056

    Article  PubMed  Google Scholar 

  10. Sun Y, Li Y, Li AM (2011) Endovascular treatment of paraclinoid aneurysms. Interv Neuroradiol 17(4):425–430

    Article  PubMed  PubMed Central  Google Scholar 

  11. Wang Y, Li Y, Jiang C, Jiang F, Meng H, Siddiqui AH, Yang X (2013) Endovascular treatment of paraclinoid aneurysms: 142 aneurysms in one Centre. J Neurointerv Surg 5(6):552–556

    Article  PubMed  Google Scholar 

  12. Yamaguchi S, Ito O, Koyanagi Y, Iwaki K, Matsukado K (2017) Microcatheter shaping using intravascular placement during intracranial aneurysm coiling. Interv Neuroradiol 23(3):249–254

    Article  PubMed  PubMed Central  Google Scholar 

Download references


This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2018R1A2B6003143). The sponsor had no role in the design or conduct of this research.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Dae Chul Suh.

Ethics declarations

Conflict of interest

All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge, or beliefs) in the subject matter or materials discussed in this manuscript.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee (name of institute/committee) and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained before procedure from all patients. The institutional review board in our institute approved this study.

Additional information


The authors reported loop microcatheter technique for coil embolization of paraclinoid aneurysms. I believe that this kind of topics is often discussed in a clinical practice. However, it seemed to be seen in few instances on the scientific paper. Their shaping technique is based on angioarchitecture obtained by three-dimensional (3D) rotational angiography. This technique using new 3D modality is now standard and reasonable. They clearly demonstrated loop microcatheter technique with two ways. This might be a good example for the readers.

Kenji Sugiu,

Okayama city, Japan.

This article is part of the Topical Collection on Vascular Neurosurgery Aneurysm

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Jia, Z.Y., Song, Y.S., Sheen, J.J. et al. Loop microcatheter technique for coil embolization of paraclinoid aneurysms. Acta Neurochir 160, 1755–1760 (2018).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • Aneurysm
  • Coiling
  • Embolization
  • Microcatheter shaping