An Institutional Experience of Fenestrated T-Bar Clip Use in The Management of Intracranial Aneurysms
Correspondence Address: Source of Support: None, Conflict of Interest: None DOI: 10.4103/0028-3886.271295
Source of Support: None, Conflict of Interest: None
Surgical management of an intracranial aneurysm is mainly clipping. Various types of clips have been designed for complex, giant, and other aneurysms. Recently, the Yasargil-fenestrated T-bar clip has been introduced for the management of such complicated aneurysms. The literature regarding its efficacy, limitations, and method of application in complicated aneurysms is limited. We used the fenestrated T-bar clip in four patients of intracranial aneurysms – middle cerebral artery cortical branch aneurysm, anterior communicating artery partially thrombosed aneurysm, internal carotid artery paraclinoid simple aneurysm, and giant aneurysm. All aneurysms were successfully clipped with no residue or branch occlusion. The recovery of all patients was satisfactory. The fenestrated T-bar clip effectively reconstructed the parent artery and occluded the aneurysm in all cases. The application of this clip may be advantageous over the clip application in some uniquely challenging cases.
Keywords: Aneurysm, anterior communicating artery, fenestrated T-bar clip, internal carotid artery, middle cerebral artery
Since 1938, when Dandy used the V-shaped malleable silver clip for an internal carotid artery (ICA) aneurysm, there has been tremendous evolution in clip designs and configurations., Currently, neurosurgeons use various types of clips such as curved, straight, perpendicular, fenestrated, etc. based on the morphology and location of an aneurysm. Currently, there are four clip designs which are available – McFadden Vari-Angle, Sundt Slim-Line, Sugita, and Yasargil-type clips. The last two clips are used more commonly. Recently, new clips have been introduced such as the booster clip, which augments a long clip placed on a giant aneurysm, Sundt clip, which incorporates a Dacron mesh to repair accidently torn blood vessels, and a T clip (simple or fenestrated). We are reporting our institutional experience of four challenging cases of anterior circulation aneurysms, where the fenestrated T-bar clip was used.
Four patients who had complex anterior circulation aneurysms were treated through the use of a fenestrated T-bar clip. All patients gave informed consent for the procedure and the study. The pre-, intra-, and postoperative details of each case have been described in results.
A 35-year-old male presented with a headache and vomiting of a two-month duration. Noncontrast computed tomography (NCCT) of the head revealed a partly calcified aneurysm in terminal cortical branch of right middle cerebral artery (MCA) [Figure 1]a. He was categorized as grade 1 in the Hunt and Hess classification without any neurological deficit. Preoperative CT angiography showed a fusiform aneurysm arising from posterior temporal branch of right MCA [Figure 1]b, which was confirmed on the digital subtraction angiography (DSA) [Figure 1]c. The patient underwent right pterional craniotomy, and reconstruction of the vessel wall was done using a single fenestrated T-bar clip [Figure 1]d and [Figure 1]e and one straight fenestrated clip. The intraoperative single fusiform aneurysm measuring 1.5 × 0.84 cm, which was partly calcified and partially thrombosed, was seen arising from the superior cortical branch of right MCA. The postoperative period was uneventful, and the postoperative CT angiogram showed nonvisualization of aneurysm with normal distal flow.
A 36-year-old gentleman had a sudden onset of holocranial headache of a two day duration associated with brief loss of consciousness. He had no neurological deficits. The CT scan of the head showed diffuse subarachnoid hemorrhage (SAH) involving basal cisterns. Magnetic resonance angiography (MRA) of the brain revealed an anterior communicating artery (ACom) aneurysm [Figure 2]a. A left pterional craniotomy and clipping of the ACom aneurysm was planned. The left ICA paraclinoid aneurysm was detected incidentally during the intraoprtaive period and was found arising from the ventral wall directed posteriorly [Figure 2]b. This aneurysm was missed on preoperative MRA; perhaps due to the poor quality of the MRA. As it was missed, the drilling of the anterior clinoid process was also not planned. Therefore, the left ICA paraclinoid aneurysm was clipped using a single fenestrated T-bar clip [Figure 2]c and [Figure 2]d. Both the aneurysms were clipped uneventfully. The postoperative DSA performed showed no residual neck of either of the aneurysms [Figure 2]e.
A 40-year-old female presented with a sudden onset of holocranial headache of a two day duration associated with brief loss of consciousness. The NCCT of the head was suggestive of SAH in the anterior interhemispheric fissure [Figure 3]a. The patient was categorized to be in the Hunt and Hess grade 1 classification. CT angiography of the brain was done, which revealed an ACom aneurysm [Figure 3]b. A left pterional craniotomy and clipping of the aneurysm was done under Indocyanine green dye (ICG) video-angiography (VA) using a single fenestrated T-bar clip [Figure 3]c. During the intraoperative period, a bilobed aneurysm of size 0.5 × 0.4 × 0.4 cm partially thrombosed arising from inferior wall of proximal segment of distal anterior cerebral artery (A2) and ACom was found. Instead of using the routine fenestrated clip, a fenestrated T-bar clip was used which covered larger area. A single clip was used. The bilateral A2, bilateral recurrent artery of Heubner and perforators were filling and were visualized under ICG-VA [Figure 3]d. The postoperative CT angiogram showed no residual neck [Figure 3]e.
A 45-year-old male presented with a persistent headache of a three month duration and left occulomotor nerve palsy manifesting as ptosis and ophthalmoplegia. There was no SAH. A CT scan of the head and a CT angiography suggested a left paraclinoid ICA giant aneurysm measuring 4 × 3.5 × 3 cm. During surgery, the aneurysm was found to be arising from the dorsal wall of ICA, directed posterior/superior/medial. The fenestrated T-bar clip was used to clip the neck and reconstruct ICA in fenestration. ICG dye confirmed normal flow in the distal ICA.
Follow-up: Every patient was followed up with 14 days after their surgery, then at the one month period and then every three months for the following year. We did not routinely perform CT angiography in every patient, as some patients were asymptomatic.
While posterior circulation aneurysms are mostly treated by endovascular procedures, aneurysms of anterior circulation are treated by both open and endovascular means, and they may be complex in terms of anatomical location or morphology. These complex aneurysms may require drilling of the anterior clinoid process, cutting the proximal and distal dural ring, with proximal ICA control in neck, trapping with/without bypass, vessel reconstruction, wrapping with/without clip reinforcement, etc.,, The above-mentioned maneuvers are needed to expose aneurysm neck as much as possible, view complete morphology of aneurysm, and to find suitable site to which the clip can be applied. But difficulty arises when the origin of the aneurysm is not directly in the surgeon's view. In such cases, fenestrated clips might be used as per the preference of the surgeon. A fenestrated T-bar clip is a type of fenestrated clip with a slight change in the configuration of the clip arms. Routine fenestrated clips are either straight or angled and have only one side arm, which can be straight, curved, angled. It can cover the aneurysm's neck in one dimension only. In contrast, the fenestrated T bar is a type of fenestrated clip with two limbs in either direction (just like letter “T”) that covers vessels in two dimensions [Figure 4]a, [Figure 4]b, [Figure 4]c. We searched in PubMed with terms such as “fenestrated T bar clip,” “intracranial aneurysm,” “complex aneurysm clip,” and found only a single case report in the literature describing the use of the said clip.
In this study, we carefully selected the aneurysms in which fenestrated T-bar clip could be applied as it is not routinely required. Aneurysms such as terminal MCA cortical branches, which may not be suitable for trapping or anastomosis (small diameter) as in Case 1, can be treated by it. In this case, the routine fenestrated clip was an alternative option that could have resulted in complete obliteration, but which may have otherwise required multiple clips. The single T-bar clip application resulted in complete obliteration of neck with the reconstruction of vessel as in Case 3 also. This was possible because the T-bar clip covers a larger area, when applied in the center with clip arms on either side of the vessel. In contrast, the simple fenestrated clip stays on one side of vessel only and can be applied from either side.
Case 2 of the paraclinoid aneurysm might have required drilling of anterior clinoid process (ACP) with or without proximal ICA control. However, it was safely clipped using the fenestrated T-bar clip without drilling of ACP. This part of the ICA does not bear any branch from ventral wall, so there was no fear of getting any perforator in the clip. The alternative was routine fenestrated clip either straight or angled inferiorly. This would have not given enough space in the absence of drilled ACP.
In Case 4, the neck of aneurysm was wide. Only using simple fenestrated clips may have required a greater number of clips overall. Applying a fenestrated T-bar clip in the center covered a significant length, eliminating the need for extra simple fenestrated clips.
Fenestrated T-bar clips effectively reconstruct the parent artery. The application of this clip may be advantageous over conventional clip application in some uniquely challenging aneurysm cases. This is because a single T clip is sufficient to reconstruct the long segment of the artery, take care of neck in two dimensions, and can be applied to the center of the aneurysm if the surgeon is having difficulty maneuvering its lateral side. Thus, fewer clips are required, which reduces the cost of surgery and minimizes artifacts on postoperative imaging. In addition, there is a reduced need for excessive maneuvering of the clip applicator when endeavoring to find a satisfactory site for clip application. However, the decision to use the T-bar clip must be taken carefully in consideration of the aneurysm morphology. In the future, a study with a larger sample size would provide more insight into the overall advantages and disadvantages of the fenestrated T-bar clip.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
[Figure 1], [Figure 2], [Figure 3], [Figure 4]