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Table of Contents    
Year : 2018  |  Volume : 66  |  Issue : 3  |  Page : 804-806

Proposed solution for dorsal internal carotid artery aneurysms: Suggestion of a novel new clip design

1 Department of Neurosurgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India
2 Centre of Excellence in Industrial and Product Design, PEC University of Technology, Chandigarh, India

Date of Web Publication15-May-2018

Correspondence Address:
Dr. Ashish Aggarwal
Department of Neurosurgery, Postgraduate Institute of Medical Education and Research, Chandigarh - 160 012
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0028-3886.232282

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 » Abstract 

Dorsal internal carotid artery (ICA) aneurysms are notorious for their high morbidity and mortality. They have an extremely fragile wall and have a high chance of rupture and clip slippage during the intraoperative and postoperative period. Strategies proposed to mitigate these problems encompass including part of the normal ICA wall in addition to neck of aneurysm in clip blades, as well as the use of encircling materials (silicon, cellulose, Weck's clip) over a clip. The Achilles' heel of the problem is to take an appropriate thickness of the normal ICA in clip blades. Too less or too much of this can spell disaster. This is easier said than done during an actual surgical procedure. So, in this difficult situation, is there any better method of clipping? We propose a fenestrated clip in which the clip blades are placed just at the beginning of fenestration and at right angles to the clip. This occludes the aneurysm taking part of the normal ICA wall in the clip blades. The fenestration hugs the ICA and prevents clip slippage. This has been explained with appropriate figures in the two and three-dimensional format. There cannot be a single stop solution for a complex disease like dorsal ICA aneurysm. The present proposed design is an attempt to provide a better clipping chance in these difficult aneurysms. Future work on this design can prove its usefulness.

Keywords: Difficult clipping, dorsal ICA aneurysms, fragile, normal ICA wall, new clip design
Key Message: Dorsal wall paraclinoid segment internal carotid artery (ICA) aneurysms are blister aneurysms with a wide neck and fragile walls, and are highly prone to get avulsed during surgical clipping. A novel fenestrated clip has been proposed to overcome this difficult situation. Its clip blades are placed just at the beginning of fenestration and at right angles to the clip.This occludes the aneury

How to cite this article:
Aggarwal A, Singh M, Kalra P. Proposed solution for dorsal internal carotid artery aneurysms: Suggestion of a novel new clip design. Neurol India 2018;66:804-6

How to cite this URL:
Aggarwal A, Singh M, Kalra P. Proposed solution for dorsal internal carotid artery aneurysms: Suggestion of a novel new clip design. Neurol India [serial online] 2018 [cited 2022 Aug 18];66:804-6. Available from: https://www.neurologyindia.com/text.asp?2018/66/3/804/232282

Intracranial aneurysms commonly arising from arterial branching points are berry aneurysms and have a defined neck, which makes the work of clipping a little less complicated. However, there is a distinct subset of patients in whom the aneurysm directly arises from the dorsal wall of internal carotid artery (ICA). In addition to arising from the nonbranching point, these aneurysms are blister-like with thin fragile walls, have a broad-based neck which is not clearly defined, and these aneurysms are not unusually adherent to the surrounding brain parenchyma.[1],[2] They frequently rupture during surgery.[1],[3] Various treatment options available include a direct clipping (by including a small part of normal vessel in the clip jaws); or, its wrapping, clipping and wrapping, and/or institution of an arterial bypass with aneurysm trapping. One of the commonly taught nuances of surgical clipping is to take a part of the normal ICA wall (in addition to the dorsally placed aneurysm) in the clip blades.[2],[4],[5] The situation is not very conducive even for the available endovascular options including coiling, stenting with coiling, flow diverters etc.[1],[2] Despite the availability of these plethora of methods, there is a higher-than-usual morbidity and mortality associated with this subset of patients harbouring a dorsal wall aneurysm.[1] None of the available methods provides a perfect solution for this condition, and hence, the quest to find the so-called panacea continues.

The clip design

During clipping of a dorsal ICA aneurysm, there is a risk of laceration of aneurysmal wall or clip slippage due to the pulsations of ICA.

We propose a possible solution to this problem in the form of a new novel clip design. In this design, we propose a fenestrated clip in which the occluding blades (clip jaws) are at the near end of fenestration, i.e., these are placed just at the starting of the fenestration and at right angle to the clip. We prepared a three-dimensional model of the design using Solid works software (Dassault Systèmes SolidWorks Corporation Waltham, MA) [Figure 1]a, [Figure 1]b, [Figure 1]c, [Figure 1]d, Video 1.
Figure 1: Different views of the proposed clip in the three-dimensional model. The clip blades are just at the beginning of the fenestration and are at right angles to the clip. (a) Oblique view seen from the right side and the hub end; (b) oblique view seen from the fenestration end; (c) Side view of the clip showing clip blades at right angle to the clip; and, (d) oblique view seen from the left side

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This clip design will act in the following manner: The blades of the clip occlude the dorsally placed aneurysm taking a part of the normal ICA wall, as has been suggested earlier. Simultaneously, the fenestration hugs the ICA. [Figure 2]a and [Figure 2]b. This hugging action of fenestration will prevent clip slippage. We propose a variable fenestration diameter with the length of the clip blades also being of various sizes. In addition, the shape of clip blades can be varied, e.g., having curved clip blades or having clip blades on both sides of the clip hub.
Figure 2: Diagram of the proposed new clip during the clipping showing (a) an end-on view and (b) oblique view. The blades are at a right angle to the clip and are placed at the beginning of the fenestration. The clip blades take a part of the normal ICA wall in addition to the aneurysm during its clipping

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 » Discussion Top

The literature review singularly points to the fact that these dorsal ICA aneurysms are difficult to clip owing to their morphology.[1],[2],[4],[6],[7] Pathologically, these aneurysms are composed of only a layer of adventitia and blood clot and are devoid of internal elastic lamina and media, which leads to an abnormally high fragility.[1],[3],[8],[9],[10],[11],[12]

The fragility of the wall and an unfavorable relative size of the aneurysm and ICA further complicates the matter in that it leads to a higher chance of postoperative bleeding, presumably because of tearing of the aneurysm or the clip slippage.[1],[2],[6],[7]

Several authors have tried to classify these aneurysms depending upon their angiographic appearance and intraoperative microsurgical anatomy.[2],[4] The take-home message in these classification systems is that during surgery, a portion of the healthy wall of ICA should be taken in the clip blades. Herein, lies a problem. Intraoperatively, the surgeon has to take a decision on how much of the ICA wall should be taken in the clip blades? The surgeon can err on either side. He may incorporate too much of the vessel wall in order to ensure that there is no chance of aneurysmal laceration or avulsion from the ICA, while closing the clip blades. However, in this scenario, while the aneurysm has been secured, the flip side is that it can lead to ICA stenosis/ compromise, with the possibility of an ischemic stroke. On the other hand, taking too little of the vessel wall in the proximity of the aneurysm has the potential risk of causing aneurysmal rupture or laceration as well as clip slippage in the postoperative period.

Another important point is that sometimes there is a tendency of the applied clip to slip off, especially in large circumferential aneurysms. To mitigate this problem, various authors have suggested the use of an encircling material around the aneurysmal neck to secure the primary clip.[9],[10] Shigeta et al., suggested wrapping the ICA with cellulose or using Weck's clips after the primary clipping of the aneurysm.[2] This requires either the use of two different clips or the use of cellulose, which may not be efficacious.

Hence, a mechanism is needed to hold the clip in place. The present proposal of this new clip design is intended to take care of this problem. The surgeon can confidently take only the bare minimum required of the healthy wall of the ICA trunk in the proximity of the aneurysmal neck in the clip. The ICA wall hugging action of the clip fenestration ensures that the clip will not slip.. The advantage of the proposed innovation over the previous clipping techniques is that the work done by two clips earlier can be performed by a single clip.

We clearly reiterate that the mechanical forces as well as the closing force of the proposed clip have not been tested in our clip design. However, what we are proposing is a new clip design, which can be potentially developed to mitigate the problems associated with the clipping of a blister dorsal wall ICA aneurysm that is often prone to an intraoperative rupture during its surgical clipping.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

 » References Top

McLaughlin N, Laroche M, Bojanowski MW. Blister-like aneurysms of the internal carotid artery-management considerations. Neurochirurgie 2012;58:170-86.  Back to cited text no. 1
Shigeta H, Kyoshima K, Nakagawa F, Kobayashi S. Dorsal internal carotid artery aneurysms with special reference to angiographic presentation and surgicalmanagement. Acta Neurochir (Wien) 1992;119:42-8.  Back to cited text no. 2
Yu-Tse L, Ho-Fai W, Cheng-Chi L, Chu-Mei K, Yi-Chou W, Tao-Chieh Y. Rupture of symptomatic blood blister-like aneurysm of the internal carotid artery: Clinical experience and management outcome. Br J Neurosurg 2012;26:378-82.  Back to cited text no. 3
Bojanowski MW, Weil AG, McLaughlin N, Chaalala C, Magro E, Fournier JY. Morphological aspects of blister aneurysms and nuances for surgical treatment. J Neurosurg 2015;123:1156-65.  Back to cited text no. 4
McLaughlin N, Laroche M, Bojanowski MW. Surgical management of blood blister-like aneurysms of the internal carotid artery. World Neurosurg 2010;74:483-93.  Back to cited text no. 5
Ogawa A, Suzuki M, Ogasawara K. Aneurysms at nonbranching sites in the surpaclinoid portion of the internal carotid artery: Internal carotid artery trunk aneurysms. Neurosurgery 2000;47:578-83.  Back to cited text no. 6
Sim SY, Shin YS, Cho KG, Kim SY, Kim SH, Ahn YH, et al. Blood blister-like aneurysms at nonbranching sites of the internal carotid artery. J Neurosurg 2006;105:400-5.  Back to cited text no. 7
Ishikawa T, Nakamura N, Houkin K, Nomura M. Pathological consideration of a “blister-like” aneurysm at the superior wall of the internal carotid artery: Case report. Neurosurgery 1997;40:403-6.  Back to cited text no. 8
Ambekar S, Madhugiri V, Pandey P, Yavagal DR. Cerebral aneurysm treatment in India: Results of a national survey regarding practice patterns in India. Neurol India 2016;64, Suppl S1:62-9.  Back to cited text no. 9
Jha AN, Gupta V. Blister aneurysms. Neurol India 2009;57:2-3.  Back to cited text no. 10
[PUBMED]  [Full text]  
Kurokawa Y, Wanibuchi M, Ishiguro M, Inaba K. New method for obliterative treatment of an anterior wall aneurysm in the internal carotid artery: Encircling silicone sheet clip procedure – Technical case report. Neurosurgery 2001;49:469-72.  Back to cited text no. 11
Sekula RF Jr, Cohen DB, Quigley MR, Jannetta PJ. Primary treatment of a blister-like aneurysm with an encircling clip graft: Technical case report. Neurosurgery 2006;59(Suppl 1):168.  Back to cited text no. 12


  [Figure 1], [Figure 2]


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