J Korean Neurosurg Soc.  2014 Dec;56(6):463-468. 10.3340/jkns.2014.56.6.463.

Unexpected Detachment of Solitaire Stents during Mechanical Thrombectomy

• Kim ST
• Jin SC
• Jeong HW
• Seo JH
• Ha SY
• Pyun HW

• KMID: 2191131
• DOI: http://doi.org/10.3340/jkns.2014.56.6.463

Abstract

OBJECTIVE
Unexpected Solitaire stent detachment can occur during mechanical Solitaire thrombectomy. The purpose of this study was to retrospectively evaluate the influencing factors causing unexpected Solitaire stent detachment and the clinical outcomes.
METHODS
Between October 2011 to December 2013, 232 cases of mechanical Solitaire thrombectomy for acute ischemic stroke were performed in 3 stroke centers. During this period, we encountered unexpected Solitaire stent detachments during mechanical Solitaire thrombectomies in 9 cases.
RESULTS
Solitaire stents unexpectedly detached in 9 cases (3.9%) during the retrieval of Solitaire stents. The median patient age was 76 years. The occlusion sites of the unexpected stent detachment were the proximal middle cerebral artery (MCA) in 7 cases and the internal carotid artery in 2 cases. The sizes of the stents that unexpectedly detached were 6x30 mm in 7 cases, 5x30 mm in 1 case, and 4x20 mm in 1 case. Four patients had unexpected detachment at the first retrieval, 1 patient at the second, 3 patients at the third, and 1 patient at the fifth. In all of the cases of unexpected detachment at the first retrieval, the stent deployment site was the proximal MCA. After detachment, a proximal marker of the Solitaire stent was observed in 3 patients. However, no marker was visible in the remaining 6 patients.
CONCLUSION
Unexpected Solitaire stent detachment should be considered in the first instance of stent retrieval for a relatively large-diameter stent, especially in elderly patients with MCA occlusions.

Keyword

Stroke; Thrombectomy; Stents

MeSH Terms

Aged
Carotid Artery, Internal
Humans
Middle Cerebral Artery
Retrospective Studies
Stents*
Stroke
Thrombectomy*

Figure

• 

  Fig. 1 A : In patient No. 4, after mechanical Solitaire thrombectomy of a primary lesion (internal carotid artery, cavernous segment), the thrombus migrated to the distal lesion. Left internal cerebral artery angiography reveals occlusion of the inferior branch after the bifurcation of the MCA at the M2 segment (arrow). B : After navigation of the microcatheter via the occluded vessel, selective angiography is performed. C : The anteroposterior (AP) and lateral (LAT) views of left internal carotid artery angiography after the deployment of a Solitaire stent (size : 6×30 mm) reveals partial reopening of the vessel with the stent in situ. D : After unexpected detachment, there is no anterograde blood flow. Furthermore, the proximal marker of the Solitaire stent is not visible. Finally, the Solitaire obviously moved to the internal carotid artery. It appears that the Solitaire is partially retrieved. E : After navigation of the microcatheter with a microwire beyond the thrombus on a map, anterograde flow is restored again. The Solitaire obviously moved to the distal middle cerebral artery. The arrow indicates the distal marker. F : Tirofiban (1.0 mg) injection via a microcatheter is performed. The acute angle of the MCA is changed to an obtuse angle (arrow). Furthermore, compare with immediately after unexpected detachment, the Solitaire stent moved to the distal area. MCA : middle cerebral artery.

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  Fig. 2 A : After unexpected detachment, in stent balloon angioplasty with a double-lumen balloon catheter is performed (patient No. 1). B : Because of MCA rupture during balloon angioplasty, contrast leakage is observed. C : Internal trapping with a coil via the double-lumen balloon catheter is performed.

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  Fig. 3 A : An anteroposterior view of the right internal carotid artery angiography after deployment of a Solitaire stent (size 6×30 mm) in patient No. 2 reveals partial reopening of the MCA flow with the stent in situ. B : After unexpected detachment, there is no anterograde blood flow. The solitaire obviously moved to the internal carotid artery. In this case, the proximal marker of the Solitaire stent is visible (arrow). C : Double stenting is performed with a second, smaller Solitaire stent (4×20 mm). Compare with immediately after unexpected detachment, the Solitaire stent moved to the distal area. The thrombus that was caught by the distal marker of the first Solitaire stent is visible (arrow). Anterograde flow is restored again.

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