Radical treatment of ruptured dissecting aneurysm on the P1 segment with monotherapy using multiple LVIS stents
- 1 Neurosurgery, Kobe City Medical Center General Hospital Department of Neurosurgery, Kobe, Hyogo, Japan
- 2 Neurosurgery, Kyoto University Graduate School of Medicine Faculty of Medicine, Kyoto, Japan
- Correspondence to Dr Natsuhi Sasaki; nsasaki@kuhp.kyoto-u.ac.jp
Abstract
The standard endovascular treatment for ruptured dissecting aneurysm is a parent artery occlusion. However, this treatment is unsuitable when the artery of the lesion gives off perforating vessels that supply blood to critical regions or when the collateral flow cannot be expected due to the sacrifice of the parent artery. Here, we present an infrequent case of ruptured dissecting aneurysm on P1 segment of the posterior cerebral artery. The aneurysm had little sac for coiling and the artery of the lesion had some perforator branches; thus, we selected the monotherapy with three overlapping low-profile visualised intraluminal support stents as radical treatment, which resulted in prompt obliteration of the aneurysm. The patient was fully recovered at 3 months after the procedure. Previous studies have reported the effectiveness of multiple stents alone for dissecting aneurysms, whereas this case showed that overlapping stents may also be effective on the P1 segment.
Background
Ruptured dissecting aneurysms (DAs) of the posterior cerebral artery (PCA) are relatively uncommon and are often on the P2 segment of PCA or beyond.1 2 In the few reports of ruptured DA involving the P1 segment,3–6 cases that were treated and result in good outcomes are extremely rare.7 8 For ruptured DA, endovascular treatment involving parent artery occlusion (PAO) as a radical therapy is generally employed, and surgical interventions include bypass and trapping.6 8 However, if some perforator branches arise from an artery of a lesion, as the P1 segment giving off branches to the brainstem and thalamus, parent-vessel sacrifice could induce significant complications. Therefore, treatment of ruptured DA on the P1 segment is challenging and still remains controversial. By contrast, a procedure using multiple stents or flow diverters (FDs) alone for ruptured DA to prevent rebleeding and repair the parent artery is recently reported to be feasible.9 10 Herein, we report a case of haemorrhagic P1 DA, which was successfully treated with overlapping three low-profile visualised intraluminal support (LVIS) stents alone while preserving the parent artery and perforators and without any subsequent complications.
Case presentation
A woman in her 40s experienced a sudden-onset headache. Four hours later, while boarding a plane, her headache worsened and she experienced vomiting, which was followed by loss of consciousness. The patient was in a coma on arrival at the hospital, and CT demonstrated diffuse subarachnoid haemorrhage (SAH) in the cisterns and all ventricles, which was classified as Hunt and Kosnik grade V and Fisher group IV. Her condition was further complicated by acute hydrocephalus (figure 1A).
(A) Initial CT demonstrated subarachnoid haemorrhage and acute hydrocephalus. (B) Cerebral angiography showed the irregular shape (red arrow) of the caudal side at the P1 segment of the posterior cerebral artery.
Investigations
The initial cerebral angiography demonstrated that the P1 segment had an irregular shape (figure 1B); however, treatment to prevent rebleeding was not performed because of insufficient evidence regarding the cause of SAH. Only bilateral external ventricular drains placement for acute hydrocephalus was performed on the first day. After surgery, the patient was admitted to the intensive care unit under general anaesthesia. On the following day, the patient was re-evaluated with cerebral angiography to assess differences from the initial image. The findings, including the irregular shape of the P1 segment, remained unchanged; thus, the patient was assessed using contrast-enhanced MRI to identify the rupture point. T1 contrast-enhanced imaging revealed vessel wall enhancement in the P1 segment (figure 2A). Moreover, three-dimensional reconstruction on cerebral angiography demonstrated a divided lumen (figure 2B). These images confirmed the lesion and established the cause of SAH to be the ruptured DA of the P1 segment.
(A) Two consecutive slices of the T1-weighted image (T1WI; upper row) and T1 contrast- enhanced image (T1CE; lower row) of the MRI indicating the rupture point. (B) Sagittal view of the three-dimensional (3D) construction on angiography showing the dissection line (yellow arrowhead) in the left PCA. The yellow circle represents the ostia of the left superior cerebellar artery. (C) 3D construction revealed the presence of perforator branches (blue arrowhead) opposite to the wall of the irregular shape (blue arrow). BA, basilar artery; Lt., left; PCA, posterior cerebral artery; Rt., right.
Treatment
Perforating branches were observed on the P1 segment (figure 2C). Furthermore, general anaesthesia and fragility of the vessel wall due to the dissection prevented the performance of the balloon occlusion test (BOT). Hence, the sacrifice procedure was not chosen as a treatment method, and multiple overlapping stents as radical therapy was chosen instead. After carefully explaining to the patient’s family that this case was an extremely rare type of DA and that there was no established treatment, we showed the viable treatment options, including conservative therapy, and after completely explaining the risks and benefits of all treatments methods, we obtained consent from the family for this treatment. Considering the degree of metal coverage, we decided to use LVIS stents. Loading doses of aspirin (200 mg) and clopidogrel (300 mg) were administered through a gastric tube to prevent thrombosis. However, antiplatelet therapy test with VerifyNow system (Accumetrics, San Diego, California, USA) indicated insufficient antiplatelet effect (aspirin reaction unit (ARU), 581 and P2Y12 reaction unit (PRU), 289); therefore, cilostazol (200 mg) and prasugrel (30 mg) were additionally administered. A 7-French guiding catheter was placed at the V2 segment of the left vertebral artery (VA) and the tip of a 4.2-French distal access catheter was positioned at the union of the VA. The first LVIS Blue stent (MicroVention-Terumo, Tustin, California, USA) (3.5×22 mm) was deployed from the P2 segment to the basilar artery, aiming at sufficient lesion coverage. Angiography confirmed the persistence of the irregular shape; thus, the second LVIS Blue stent (3.5×17 mm) was deployed to overlap the irregular shape. However, the irregular shape on the P1 segment remained on the succeeding angiogram; hence, an additional overlapping stent, the third LVIS Blue stent (4×17 mm), was deployed (figure 3A,B). The angiogram performed immediately after the third stenting revealed the P1 segment having a normal shape, and cone-beam CT showed complete stents apposition to the vessel wall (figure 3C,D), indicating the completion of the procedure. On completion of the treatment, VerifyNow showed an ARU value of 350 and a PRU value of 156.
(A) Initial image of the working angle. The width of the parent artery was measured at three key points. (B) The image following placement of three low-profile visualised intraluminal support (LVIS) stents. Red, blue and yellow lines represent the first, second and third stents, respectively. (C) Final angiographical image. Note that the irregular shape of the P1 segment was no longer observed. (D) Cone-beam CT showing good positon of the helical tantalum wires of the LVIS stents at the vessel wall.
Outcome and follow-up
Follow-up MRI on postoperative day (POD) 1 demonstrated no ischaemic changes (figure 4A). The patient was repeatedly assessed angiographically on PODs 3, 7 and 14 (figure 4B), as it was necessary to carefully confirm for recurrence of cerebral aneurysm or in-stent stenosis, which was difficult to assess with MR angiography due to stent artefacts. The aneurysmal component did not recur, and no in-stent stenosis was observed. Dual oral antiplatelet therapy (aspirin, 100 mg/day and prasugrel, 3.75 mg/day) was continued. Bilateral external ventricular drains were removed on PODs 5 and 6 after passing the clamp trial, but ventriculoperitoneal shunt placement was performed on POD 30 due to the development of hydrocephalus. Although the patient had executive function disorder and difficulty in sitting without assistance on POD 7, the patient’s executive dysfunction had improved at the time of transfer to a rehabilitation hospital on POD 45, and she only had the loss of her strength caused by the long-term bed rest; therefore, the modified Rankin scale (mRS) score was 2, which improved to mRS 0 at 3 months postoperative. Follow-up angiography at 4 months revealed complete occlusion of the DA (figure 4C).
(A) Diffusion-weighted image revealed no cerebral infarction. (B) Angiographical image on postoperative day 3 showed patency of left posterior cerebral artery. (C) Angiographical figure 4 months after the procedure. No intrastent stenosis or irregular shape was present. (D) The left, middle and right photograph shows the single, double and triple low-profile visualised intraluminal support stent, respectively. The cell size decreased as the number of stents increased.
Discussion
Our case was precisely diagnosed with DA of the P1 segment using T1 contrast-enhanced imaging (figure 2A), as in a study by Omodaka et al.11 In the few previous reports of haemorrhagic DA including the P1 segment in which individual cases could be identified, PAO, conservative therapy, proximal ligation and coiling of the aneurysm sac were performed as treatment (table 1),3–8 while the radical treatment method should be PAO or bypass and trapping because of fragility of the vessel wall. When these radical treatments are not available due to the presence of perforating branches or a problem of collateral flow, if there is space in the aneurysmal sac of the DA, coil embolisation or partial clipping could be considered as an alternative therapy.7 12 However, if there is no space in the sac of the DA, as in our case, not even alternative therapy could be chosen. In previous reports, DAs were relatively large or no information on the size of the aneurysm was provided (table 1).3–8 Ruptured DA with little space in the sac on the P1 segment, as in our case, was not only extremely rare but has very limited treatment options; therefore, we report a case successfully treated with overlapping stents.
Cases of ruptured dissecting aneurysm involving the P1 segment
| Year | Author | N | Age, Sex | SAH grade | Location | Size (mm) | Shape | BOT | Treatment for SAH | Complications | Following events | Outcome | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| BOT, balloon occlusion test; F, female; GOS, Glasgow outcome scale; H&H, Hunt and Hess grade; Lt., left; M, male; mRS, modified Rankin scale; N/A, not available; OL, occipital lobe; PA, parent artery; PAO, parent artery occlusion; PCA, posterior cerebral artery; Rt., right; SAH, subarachnoid haemorrhage. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 1991 | Pozzati3 | 1 | 38, F | N/A | Rt. P1 | N/A | Stenosis | N/A | Conservative | − | Shape returned to normal | Functional independence in 1 year | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 2001 | Ciceri7 | 1 | 13, M | N/A | P1-2 junction | N/A | N/A | N/A | Coiling while preserving PA |
None | No recurrence | N/A | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 2007 | Nistri4 | 1 | 58, M | N/A | Rt. P1–2 | N/A | Blister | N/A | Conservative | − | Disappearance of the focal blister |
Normal activities in 4 months | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 2010 | Shinno5 | 1 | 47, F | N/A | Rt. P1–2 | N/A | Fusiform | N/A | Proximal ligation | N/A | Recurrence at 5 weeks no retreatment no change for 3 years | Functional independence | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 2012 | Wang6 | 2 | 39, M | H＆H Ⅴ | Rt. P1 | 10 | Fusiform | N/A | PAO with coil | N/A | N/A | mRS5 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 23, F | ICH | Rt. P1 | 25 | N/A | N/A | Trapping | N/A | N/A | mRS6 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 2015 | Park8 | 4 | 66, F | H＆H Ⅱ | Rt. P1–two junction | 6.1 | Fusiform | None | PAO with coil | None | No recurrence | mRS0 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 42, M | H＆H Ⅱ | Lt. P1 | 12.3 | Fusiform | Tolerable | PAO with coil | None | No recurrence | mRS0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 47, M | H＆H Ⅳ | Rt. P1–two junction | 25.7 | Partially thrombosed | None | PAO with coil | N/A | Recurrence at 3 hour with rebleeding | mRS6 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 72, M | H＆H Ⅳ | Lt. P1 | 28.2 | Partially thrombosed | None | PAO with coil | Infarction | No recurrence | mRS4 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ethics statements
Patient consent for publication
Acknowledgments
We would like to thank the patient who consented to the publication of this report and Editage (www.editage.com) for English language editing.
Footnotes
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Contributors Supervised by NS. NS, HI, MS and NS provided treatment and management of the patient. Report was written by NS and HI. MS assisted in the acquisition of data and obtaining of patient’s consent.
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Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
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Competing interests None declared.
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Provenance and peer review Not commissioned; externally peer reviewed.
- © BMJ Publishing Group Limited 2021. No commercial re-use. See rights and permissions. Published by BMJ.
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