We report a case of delayed rupture of an anterior communicating artery (Acom) pseudoaneurysm following mechanical thrombectomy (MT) of a distal artery occlusion using a stent retriever. An elderly patient with right hemiparesis showed left proximal internal cerebral artery and middle cerebral artery occlusions. During MT, a fragmented thrombus moved to the anterior cerebral artery (ACA). A stent retriever was deployed to the occluded ACA, and the Acom and proximal ACA segment were significantly straightened. Additionally, we attempted a blind exchange mini-pinning (BEMP) technique, but a subarachnoid hemorrhage (SAH) occurred. Bleeding was almost entirely absorbed 9 days after the procedure, but the SAH recurred at 20 days, and computed tomography angiography revealed a new pseudoaneurysm formation in the Acom. We suggest that the proposed mechanism of pseudoaneurysm formation was likely due to the dislocation and avulsion of the Acom perforators when the ipsilateral ACA was pushed and pulled during MT.
Mechanical thrombectomy (MT) has been established as the primary treatment for large vessel occlusion in acute ischemic stroke (AIS). Indications for MT are gradually increasing, with the total number of MTs performed worldwide rising year by year [
The occurrence of a pseudoaneurysm has been reported in several post-MT cases with SAH [
Here, we report a case of delayed rupture of an anterior communicating artery (Acom) pseudoaneurysm following distal occlusion thrombectomy using a stent retriever.
An elderly patient was transferred to our hospital because of a sudden change in mental status and right hemiplegia, which had occurred 80 min previously. Initial non-contrast computed tomography (NCCT) showed no high-density lesions. After intravenous injection of tissue plasminogen activator (tPA), computed tomography angiography (CTA) showed left proximal internal carotid artery (ICA) and MCA occlusions, and the patient was transferred to our hospital for further management. The patient’s National Institutes of Health Stroke Scale (NIHSS) was 19 points. Atrial fibrillation was confirmed by electrocardiography. The patient was transferred to the angiography suite as MT was required for a subsequent perfusion study.
After puncturing the right femoral artery, a 9-Fr sheath was inserted, and a 9-Fr balloon-guiding catheter (BGC) (Medtronic, Irvine, CA, USA) was catheterized to the left proximal ICA. Aspiration thrombectomy using a Penumbra pump (Penumbra, Alameda, CA, USA) was performed once using the BGC, and a large thrombus was observed. Subsequent angiography showed a recanalized ICA, an occluded MCA, and a newly occluded ipsilateral anterior cerebral artery (ACA) (
While accessing the left ACA occlusion site, the microwire moved to the right ACA once through the Acom. After navigation of the left ACA, a Solitaire 4×40-mm stent retriever was deployed at the occlusion site. Because of severe tortuosity and the acute angle between the distal ICA and ACA A1 segments, the cerebral artery was significantly straightened when the stent retriever was deployed (
Immediate NCCT revealed a massive SAH; however, the patient’s neurological status did not deteriorate. We controlled the blood pressure carefully and closely observed for neurological deterioration. Nine days after MT, NCCT confirmed that nearly no SAH had persisted. We decided to start anticoagulation with oral apixaban 2.5 mg twice daily. Follow-up NCCT on the 14th day showed a high-density lesion in the anterior part of the suprasellar cistern. Since the clinical findings improved, we did not perform a closer examination of the cistern. The patient’s mental status suddenly deteriorated on the 20th day, and CTA showed a new SAH and Acom pseudoaneurysm (
Considering that a pseudoaneurysm had occurred after MT, we prepared a coil embolization procedure. However, the patient’s family members refused treatment, and the patient died 3 days later.
To the best of our knowledge, this is the first report of Acom pseudoaneurysm formation after MT in a patient with AIS. We hypothesized that there were 2 main causes of pseudoaneurysm formation. The first probable cause is damage to the Acom perforators resulting from the straightening and distal dislocation of the Acom (
To date, pseudoaneurysm formation after MT has been reported in 3 cases [
Recently, MT has been carefully implemented even for medium vessel occlusion (MeVO) [
Distally located vessel occlusions, higher number of thrombectomy device passes, and intravenous tPA use are known risk factors for the occurrence of post-MT SAH [
In conclusion, we report a case of delayed rupture of an Acom pseudoaneurysm after distal occlusion thrombectomy using a stent retriever. In AIS cases of distal tortuous vessel occlusion, it is necessary to decide the implementation of MT more carefully. If MT is performed in these circumstances, a smaller device may reduce the symptomatic ICH rate. Furthermore, it is necessary to pay attention to whether the vessels undergoing the procedure are straightened. If straightening is significant, it may be necessary to avoid an additional procedure. Finally, if SAH occurs as a complication of MT, follow-up CTA should be conducted in a timely manner.
This work was supported by a National Research Foundation (NRF) grant (2020R1I1A3067073) funded by the Korean government.
This study was approved by the local Institutional Review Board, and the board waived the need for patient consent. Informed consent for publication was not obtained so we anonymized the patient.
The authors have no conflicts to disclose.
Concept and design: D-HS and SWY. Analysis and interpretation: D-HS and SWY. Data collection: D-HS. Writing the article: D-HS. Critical revision of the article: SWY, YD, and JKD. Final approval of the article: SWY. Obtained funding: SWY. Overall responsibility: SWY.
Angiographies and follow-up brain computed tomography angiography (CTA) of the patient. (A) After aspiration thrombectomy using a Penumbra pump in the left proximal internal cerebral artery (ICA), the left ICA angiography shows left middle cerebral artery (MCA) M1 and anterior cerebral artery (ACA) (arrows) occlusion. We performed the Solumbra technique (using Solitaire stent retriever [4×40 mm] and 5-Fr SOFIA intermediate catheter) in the left MCA M1 segment and the MCA was fully recanalized. (B) After deploying the stent retriever (Solitaire 4×40 mm, white arrow) to the distal ACA occlusion site, the blind exchange mini-pinning (BEMP) technique was tried. The left ICA angiography shows a heavily dislocated left ACA A2 segment to the medial side (white arrow), and the change in angle between distal ICA and ACA A1 segment (arrowheads). The anterior communicating artery (Acom) was also dislocated distally (black arrow). Note the change in angles between ACA A1 and A2 segments (double black arrows) before (A) and after (B) deploying the stent retriever. (C, D) Comparing lateral projection of left ICA angiographies before (C) and after (D) stent deployment in the left ACA occlusion site (black arrow), ipsilateral distal ICA and ACA A1 segments were also straightened (arrowheads). White arrow in (D) indicates the push wire of the stent retriever. (E) Working projection of left ICA angiography while removing the microcatheter over the push wire of the stent retriever shows that the angle formed by the push wire suddenly straightened (arrowheads), with no antegrade flow in the Acom and ipsilateral ACA (white arrow). (F, G) Subarachnoid hemorrhage (SAH) was confirmed by a flat panel computed tomography. The white arrows indicate SAH in bilateral interhemispheric and the Sylvian cisterns, and arrowheads indicate the push wire (F) and the stent strut of Solitaire stent retriever (G). (H) Final angiography shows fully recanalized state of left MCA and ACA. There was no visible aneurysm in Acom. (I) On the 20th day, SAH in the interhemispheric and right Sylvian cistern (black arrows) were observed again. (J) On that day, Acom pseudoaneurysm (white arrow) was observed on CTA.
A proposed mechanism of anterior communicating artery (Acom) pseudoaneurysm formation. (A, B) The angle between the left anterior cerebral artery (ACA) A1 and A2 (double black arrow), and the angle in proximal ACA A1 segment (black arrow) were changed after deploying the stent retriever, and Acom perforators also dislocated distally (arrowheads). (B, C) When attempting the blind exchange mini-pinning (BEMP) technique, microcatheter (yellow catheter) removal was attempted, and the stent retriever was pulled and pushed a lot (blue arrows) along the push wire. Eventually, Acom perforators were ruptured (arrowheads).