- Email: [email protected]
Coil Embolization Results of the Ruptured Proximal Posteriori Inferior Cerebellar Artery Aneurysm: A Single-Center 10 Years' Experience
Original Article
Coil Embolization Results of the Ruptured Proximal Posteriori Inferior Cerebellar Artery Aneurysm: A Single-Center 10 Years’ Experience Jonghoon Kim, Chulhoon Chang, Young Jin Jung
OBJECTIVE: To report a single-center experience with endovascular treatment of ruptured proximal posterior inferior cerebellar artery (PICA) aneurysms.
-
METHODS: Between January 2007 and December 2016, among 1403 patients with aneurysmal subarachnoid hemorrhage, 15 with ruptured proximal PICA aneurysms underwent endovascular embolization at our institution. Aneurysmal obliteration with a single microcatheter was performed in 9 patients. Additional microcatheter or stentassisted coil embolization was performed in 4 patients and parent artery occlusion in 2 patients.
aneurysm in the acute phase can be a good treatment modality with good patient outcomes.
-
RESULTS: Immediate angiographic results showed 10 complete occlusions (66.7%, 10/15). Five patients showed incomplete occlusion (remnant neck in 4 patients, remnant aneurysm in 1). Of those, 2 patients experienced recurrence and required conversion to microsurgical clipping. The remaining 2 patients remained in relatively stable condition. Procedure-related complications occurred in 3 patients (20%, with thromboembolic complications in 2 patients and intraprocedural rupture in 1). Clinical outcome was excellent: Glasgow Outcome Score 4 or 5 in 12 of 15 patients (80%). There was no rebleeding during follow-up.
-
CONCLUSIONS: Ruptured proximal PICA aneurysms may be effectively treated with endovascular coil embolization. A variety of coil embolization techniques are required to obliterate an aneurysm without parent artery occlusion. Given that recurrence is possible, follow-up is required. Surgical clipping can be performed for recurrence with a relatively low risk of complications, because the aneurysm is unruptured. Coil embolization of a proximal PICA
-
Key words Posterior inferior cerebellar artery - Subarachnoid hemorrhage -
Abbreviations and Acronyms GOS: Glasgow Outcome Scale PICA: Posterior inferior cerebellar artery
INTRODUCTION
P
osterior inferior cerebellar artery (PICA) aneurysms are rare and account for 0.5% to 3.0% of all intracranial aneurysms.1,2 Aneurysms arise from all segments of the PICA, but most originate from the vertebral arteryePICA junction and the proximal segment of the PICA. Direct surgical obliteration of these lesions in the acute phase is difficult because of the intimate relationship between the proximal PICA, the medulla, the lower cranial nerves (IX to XII), and important perforating branches and a large amount of subarachnoid hemorrhage make the surgical approach difficult. This limited surgical access has resulted in the consideration of endovascular coil embolization as an alternative and primary treatment modality for ruptured PICA aneurysms in the acute phase. However, endovascular coil embolization is not always easy and convenient. Aborted embolization can occur because of the relationship with the parent vessel and aneurysmal neck or a complex configuration. In these situations, various endovascular techniques are necessary for successful coil embolization. This study describes the clinical experience and technical pitfalls of coil embolization in patients with ruptured proximal PICA aneurysms. METHODS AND MATERIALS We retrospectively reviewed patients treated in our clinic for ruptured PICA aneurysms during the 10 years between January 2007 and December 2016. During this period, 10403 patients were admitted with aneurysmal subarachnoid hemorrhage, of whom 41
To whom correspondence should be addressed: Young Jin Jung, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2018) 117:e645-e652. https://doi.org/10.1016/j.wneu.2018.06.105 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2018 Elsevier Inc. All rights reserved.
Department of Neurosurgery, Yeungnam University Medical Center and Medical School, Namgu, Daegu, South Korea
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Table 1. Neurologic Deficits and Clinical Outcomes of Coil Embolization and Presence or Absence of Complications Year
Sex
Age
CC
HHG
FG
mFG
iGCS
WFNS
Neck
Height
Width
Location
Angiographic Outcome
Technique
Procedural Complications
Morbidity
Mortality
mRS 12 months
GOS 12 months
Recurrence
Additional Treatment
Remarks
1
2007
F
43
HA
2
2
2
14
2
2.80
4.00
3.80
VP junction
Remnant neck
Single MC
None
None
None
1
5
No
No
None
2
2007
F
44
HA
1
2
2
15
1
2.80
3.40
3.00
AMs
Complete
Double MC
None
None
None
1
5
No
No
None
3
2007
F
46
Drowsy
3
4
4
12
4
2.53
4.44
3.30
AMs
Remnant neck
Single MC
TEC
Infarction
None
2
4
No
No
Morbidity
4
2007
F
38
HA
2
4
4
14
2
3.41
3.82
4.54
AMs
Complete
Double MC
TEC
Expired
Expired
6
1
None
No
Mortality
5
2010
F
59
HA
2
3
2
14
2
2.72
5.35
4.58
VP junction
Remnant neck
Single MC
None
None
None
0
5
Yes, 4 years
Clipping
Recur
6
2012
F
34
HA
2
4
2
14
2
4.08
4.11
6.08
AMs
Complete
Double MC
None
None
None
0
5
Yes, 1 year
Clipping
Recur
7
2013
M
51
HA
2
4
4
14
2
2.20
2.26
2.26
AMs
Complete
Single MC
None
None
None
0
5
No
No
None
8
2013
F
43
HA
2
2
1
14
2
1.51
2.83
2.83
AMs
Remnant neck
Single MC
None
None
None
0
5
No
No
None
9
2013
F
85
HA
2
2
2
14
2
9.54
6.06
7.25
VP junction
Remnant aneurysm
SAC
None
None
Expired
6
1
None
No
Pneumonia
10
2014
F
28
HA
2
2
1
14
2
1.60
3.28
3.28
AMs
Complete
Single MC
None
None
None
0
5
No
No
None
11
2014
M
38
HA
2
2
2
14
2
NA
8.76
12.25
VP junction
Complete
PAO/double
None
None
None
0
5
No
No
None
12
2015
F
69
Stupor
2
4
4
6
5
1.48
2.21
2.21
AMs
Complete
Single MC
None
None
None
3
4
No
No
None
13
2015
F
53
Stupor
4
4
4
6
5
1.96
4.97
4.97
AMs
Complete
PAO/single
None
None
None
3
3
No
No
None
14
2016
F
51
HA
2
2
2
14
2
1.48
3.99
3.99
AMs
Complete
Single MC
None
None
None
0
5
No
No
None
15
2016
F
26
HA
1
2
2
15
1
2.92
2.92
4.50
AMs
Complete
Single MC
IPR
None
None
0
5
No
No
None
CC, chief complaint; FG, Fisher grade; mFG, modified Fisher grade; iGCS, initial Glasgow Coma Scale; WFNS, World Federation of Neurosurgical Societies grade; mRS, modified Rankin Scale; GOS, Glasgow Outcome Scale; HA, headache; VP, vertebroposterior inferior cerebellar artery; MC, microcatheter; AMs, anterior medullary segment; TEC, thromboembolic complication; PAO, parent artery occlusion; SAC, stent-assisted coiling; IPR, intraprocedural rupture; HHG, hunt hess grade.
ORIGINAL ARTICLE
COIL OF RUPTURED PICA ANEURYSM
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2018.06.105
Patient
ORIGINAL ARTICLE JONGHOON KIM ET AL.
had PICA aneurysms (2.92%, 41/1403). Of 27 patients (1.92%, 27/ 1403) received diagnoses of proximal PICA aneurysm, and 15 who underwent endovascular coil embolization were retrospectively analyzed. Eight patients (29.6%, 8/27) did not receive definitive treatment because their neurologic status was poor on arrival. Four patients underwent surgical clipping. All patients were treated by physicians specializing in neurologic intervention (J.K., C.C., and Y.J.J.). Patient sex, age, lesion location and size, neurologic grade, and radiologic findings on admission were analyzed. The presence or absence of complications associated with coil embolization and neurologic deficits and clinical outcomes were assessed (Table 1). Of 15 patients, 2 were men and 13 were women Their ages ranged from 26 to 85 years (mean standard deviation, 47.20 14.86 years). In 15 patients, SAH was observed on all initial noncontrast computed tomography. Twelve patients described having headache, 2 were stuporous, and 1 was drowsy but conscious. Hunt and Hess grade 1 was observed in 2 patients and grade 2 in 11 patients, grade 3 in 1, and grade 4 in 1. The mean aneurysm size was 4.13 1.62 mm.
Figure 1. Patient 7. Single microcatheter technique through the ipsilateral vertebral artery in a 51-year-old man with (A) diffuse subarachnoid hemorrhage and hydrocephalus. (B) Computed tomography angiographic view showing left proximal posterior inferior cerebellar artery aneurysm. (C) The aneurysm had a short height but a relatively wide neck
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All patients underwent immediate coil obliteration on the day of rupture and were operated on under general or local anesthesia according to their neurologic status; 2 or 3 neurosurgeons participated in the coil embolization. RESULTS Aneurysmal obliteration with a single microcatheter alone was performed in 9 patients (Figures 1 and 2). Additional microcatheter or stent-assisted coil embolization was performed in 4 patients (Figure 3), and parent artery occlusion was performed in 2 patients (Figure 4). Immediate angiographic results showed 10 complete occlusions (66.7%, 10/15). Five patients showed incomplete occlusion (remnant neck in 4 patients, remnant aneurysm in 1). Of those, 2 patients experienced recurrence and required conversion to microsurgical clipping during follow-up. There was no rebleeding during a follow-up time of at least 12 months (Figure 5). No patients with incomplete coil embolization experienced rebleeding in the acute phase. Procedure-related
(neck/height/width, 4.31/3.29/4.61 mm). (D, E) The aneurysm grew in the direction of normal blood flow. Using a single lazy S-shaped microcatheter through the ipsilateral vertebral artery, the aneurysm was complete obliterated with multiple coils.
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Figure 2. Patient 12. Single microcatheter technique through the contralateral vertebral artery in a 69-year-old woman. (A) Non-contrast computed tomography showed diffuse subarachnoid hemorrhage with intraventricular hemorrhage. (B) Right vertebral angiography showed a small and elongated proximal posterior inferior cerebellar artery aneurysm.
complications occurred in 3 patients (20%), with thromboembolic complications in 2 patients and intraprocedural rupture in 1 (Figure 6). A noneprocedure-related complication (progressive pneumonia resulting in death) occurred in an 85-year-old woman. Clinical outcomes were excellent after 12 months: Glasgow Outcome Score 4 or 5 in 12 of 15 patients (80%). DISCUSSION Ruptured PICA aneurysms can be more difficult to treat and manage because of their relative rarity, deep surgical location, and proximity to important perforating vessels to the brainstem and lower cranial nerves. The PICA is divided into 1) anterior medullary, 2) lateral medullary, 3) tonsilomedullary, 4) telovelotonsilar, and 5) cortical segments, as well as proximal and distal segments. Proximal segments up to the anterior medullary segment and the segment after the lateral medullary segment can be classified as distal segments. Aneurysms occurring at the junction of the
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(neck/height/width, 2.42/3.99/2.32 mm). The aneurysm grew in a direction opposite that of blood flow. (C, D) We accessed the aneurysm through the contralateral vertebral artery. The contralateral approach was more stable, making it easier to deliver coils. (E, F) The aneurysmal sac was completely obliterated with multiple coils.
vertebral artery and the PICA or aneurysms in the anterior medullary segment are considered aneurysms in the proximal PICA, and those in the lateral segment are considered distal PICA aneurysms. Aneurysms can occur at any PICA segment. Depending on the segment, the relationship between the peripheral brainstem and lower cranial nerves may change, and the treatment plan may vary depending on where an aneurysm develops in a PICA segment. Proximal PICA aneurysms may be more difficult to treat if ruptured. This is because the PICA segment often has a meandering course, forming a very complex loop between the brainstem and the lower cranial nerves, and because vital vessels leading to the brainstem originate primarily from the proximal PICA. Because of these anatomic limitations, there can be a large amount of hematoma in the subarachnoid space in the acute phase, making microsurgical clipping very difficult because of difficulty securing vision and because the boundary with surrounding critical structures is poorly defined. The PICA gives rise to perforating branches to the medullar, choroidal, and cortical
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2018.06.105
ORIGINAL ARTICLE JONGHOON KIM ET AL.
Figure 3. Patient 6. Double microcatheter technique for wide neck or incorporated branch aneurysm in a 34-year-old woman. (A) Three-dimensional rotational digital subtraction angiography showed a proximal posterior inferior cerebellar artery aneurysm, which completely invaded the parent artery (neck/height/width, 4.08/4.11/6.08 mm). (B, C)
arteries. The perforating arteries are small and arise from proximal segments and terminate in the brainstem.3 As noted, it is important to treat proximal PICA aneurysms without damaging the surrounding lower cranial nerves and small blood vessels that feed the brainstem, so as to prevent surgery-related complications. However, surgical treatment of these lesions is very difficult, and the results may be poor. According to several reports, a new neurologic deficit occurs with an incidence of 20% to 60% after surgical clipping.4-8 Al-khayat et al.4 reported good outcomes in 68.2% of patients (15/32 with GOS 1 or 2) but lower cranial nerve palsy in 71.9% (23/32) of patients who had ruptured proximal PICA aneurysms. Singh et al.8 reported a 30% incidence of complications (6/20) and mortality rate of 15% (3/ 20) after surgical treatment of 20 ruptured PICA aneurysms. Thus, surgical treatment is known to be extremely difficult. However, endovascular treatment has shown good outcomes for these lesions. Inasmuch as microsurgical treatment in the acute phase is very difficult, delayed surgery may be required in some
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Two microcatheters (Preshaped 90 and J, Excelsior SL-10 microcatheter, Stryker, Kalamazoo, Michigan, USA) were used to make frame coils. (D) Two coils were used to perform embolization while maintaining patency of the parent artery. (E) The aneurysm was nearly completely obliterated.
cases. Viswanathan et al.9 reported the surgical outcomes in 27 patients with ruptured PICA aneurysms. Ten patients underwent semi-urgent surgery between 2 and 5 days after stroke, and 17 underwent surgery more than 5 days after bleeding. Singh et al.8 reported that the operation proceeded after 32 days (mean) after ictus (range, 3 to 173 days). The development of therapeutic devices and endovascular coil techniques has made treatment of these lesions possible.10 Miricle et al.11 reported a good outcome (GOS 1 or 2) in 68% of patients (31%) with a ruptured PICA aneurysm, with a procedure-related complication rate of 6.5% (2/31). Xu et al.2 reported complication and mortality rates of 11.1% (4/36) and 2.8% in 36 patients, respectively. Gupta et al.12 reported 13 patients with ruptured proximal PICA aneurysm with complete coil occlusion in 84.6% (11/13) without intraoperative rupture, although coil loop migration occurred in 2 patients (4.61%). Of 20 patients who underwent endovascular treatment reported by Song et al.,13 2 (10%, 2/20) had an intraoperatiave rupture and 2 had
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COIL OF RUPTURED PICA ANEURYSM
Figure 4. Patient 11. Parent artery occlusion in a 38-year-old man with subarachnoid hemorrhage and intraventricular hemorrhage (A). Three-dimensional rotational digital subtraction angiography showed a fusiform aneurysm with the posterior inferior cerebellar artery originating from the sac (B). The aneurysm was completely obliterated with parent
artery occlusion (C). Fortunately, the posterior inferior cerebellar artery was supplied via muscular branch anastomosis (D). Follow-up diffusion-weighted magnetic resonance imaging showed no definite infarction (E). The patient was discharged without neurologic deficits.
Figure 5. Patient 6. Recurrence in a 35-year-old woman and conversion to clipping. Coil compaction occurred 12 months after embolization of a ruptured proximal posterior inferior cerebellar artery aneurysm. (A) The aneurysm height was too short to permit recoiling (neck/height/width,
3.92/1.41/3.32 mm). (B) The surgical field was clear and the lower cranial nerves were clearly visible. (C) Postoperative three-dimensional rotational digital subtraction angiography showed complete obliteration of the aneurysm.
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ORIGINAL ARTICLE JONGHOON KIM ET AL.
Figure 6. Patient 4. Complicated case in a 38-year-old woman with subarachnoid hemorrhage and intraventricular hemorrhage (A). Three-dimensional rotational digital subtraction angiography showed a proximal posterior inferior cerebellar artery aneurysm with a relatively narrow neck (B). Using double microcatheter technique, the aneurysm
thromboembolic complications (10%, 2/20), but 70% had good outcomes. Endovascular treatment seemed to have more favorable clinical outcomes: modified Rankin scale, 0 to 2; mean modified Rankin Scale, 1.75 for endovascular treatment versus 3.50 for surgery (P ¼ 0.152).13 Cho et al.14 reported excellent results; 10 patients were treated with coil embolization without complications. Our study was limited to the proximal PICA segment. This region is associated with the vertebral artery and important perforating arteries to the brainstem, but the study showed good results with an acceptable complication rate despite the difficulty of coiling while saving the parent artery and small perforators. Moreover, we were able to perform endovascular coil embolization the day the rupture occurred. Although the lesion location was uncommon and the lesions were diverse and invaded peripheral blood vessels, embolization using various coiling techniques and instruments was feasible. In addition, there was no acute rebleeding after coil embolization, and secondary surgical clipping was possible without late complications after recurrence.
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was completely obliterated (C). However, the lateral angiographic image obtained after coiling showed some thrombus in the vertebral artery (D). Diffusion-weighted magnetic resonance imaging showed multiple infarctions in the bilateral cerebellum (E).
This study has some limitations. This was a retrospective study in which no randomization was performed. Therefore, the patient age range was limited, and there was no one-to-one comparison with surgical treatment because only the results of intravascular surgery were assessed. In addition, given that the number of patients was small, it is unclear whether these results were representative of all possible ruptured proximal PICA aneurysms. CONCLUSIONS Using microcatheters, microwires, coils, and other materials, we have been able to perform coil embolization more easily and safely. The initial treatment for a ruptured proximal PICA aneurysm is shifting from surgical clipping to endovascular obliteration. Coil embolization of an acute-phase ruptured proximal PICA aneurysm can be carried out relatively safely and has good results. Although recurrence is possible during follow-up, there was no rebleeding in the acute phase. Therefore, even after recurrence, a secondary operation can be performed with a lower risk of
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complications because the aneurysm is unruptured. A ruptured proximal PICA aneurysm is very rare and difficult to treat and
REFERENCES 1. Petr O, Sejkorova A, Bradac O, Brinjikji W, Lanzino G. Safety and efficacy of treatment strategies for posterior inferior cerebellar artery aneurysms: a systematic review and meta-analysis. Acta Neurochir (Wien). 2016;158:2415-2428. 2. Xu F, Hong Y, Zheng Y, Xu Q, Leng B. Endovascular treatment of posterior inferior cerebellar artery aneurysms: a 7-year single-center experience. J Neurointerv Surg. 2017;9:45-51. 3. Lister JR, Rhoton AL Jr, Matsushima T, Peace DA. Microsurgical anatomy of the posterior inferior cerebellar artery. Neurosurgery. 1982;10:170-199. 4. Al-khayat H, Al-Khayat H, Beshay J, Manner D, White J. Vertebral artery-posteroinferior cerebellar artery aneurysms: clinical and lower cranial nerve outcomes in 52 patients. Neurosurgery. 2005;56:2-10 [discussion: 11]. 5. D’Ambrosio AL, Kreiter KT, Bush CA, Sciacca RR, Mayer SA, Solomon RA, et al. Far lateral suboccipital approach for the treatment of proximal posteroinferior cerebellar artery aneurysms: surgical results and long-term outcome. Neurosurgery. 2004;55:39-50 [discussion: 50-34]. 6. Horowitz M, Kopitnik T, Landreneau F, Krummerman J, Batjer HH, Thomas G, et al.
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often presents with varied morphology. However, coil embolization may become a useful and promising option for treatment.
Posteroinferior cerebellar artery aneurysms: surgical results for 38 patients. Neurosurgery. 1998;43: 1026-1032. 7. Lee KS, Gower DJ, Branch CL Jr, Kelly DL Jr, McWhorter JM, Bell WO. Surgical repair of aneurysms of the posterior inferior cerebellar artery: a clinical series. Surg Neurol. 1989;31:85-91. 8. Singh RK, Behari S, Kumar V, Jaiswal AK, Jain VK. Posterior inferior cerebellar artery aneurysms: anatomical variations and surgical strategies. Asian J Neurosurg. 2012;7:2-11. 9. Viswanathan GC, Menon G, Nair S, Abraham M. Posterior inferior cerebellar artery aneurysms: operative strategies based on a surgical series of 27 patients. Turk Neurosurg. 2014;24:30-37.
12. Gupta V, Mulimani N, Kumar A, Ahuja C, Mathuria SN, Khandelwal N. Endovascular treatment of ruptured proximal PICA aneurysms: a single-center 5-years experience. Neurol India. 2014; 62:269-275. 13. Song J, Park JE, Chung J, Lim YC, Shin YS. Treatment strategies of ruptured posterior inferior cerebellar artery aneurysm according to its segment. Surg Neurol Int. 2017;8:155. 14. Cho KC, Kim Y, Suh S, Joo J, Hong CK. Multidisciplinary management for the treatment of proximal posterior inferior cerebellar artery aneurysms. Neurol Res. 2017;39:403-413.
10. Kim J, Jeon I, Chang C, Jung Y. Technical consideration for coiling of ruptured proximal posterior inferior cerebellar artery aneurysm. J Korean Neurosurg Soc. 2018. https://doi.org/10.3340/ jkns.2017.0299. [Epub ahead of print].
Conflict of interest statement: This work was supported by the 2014 Yeungnam University Research Grant.
11. Mericle RA, Reig AS, Burry MV, Eskioglu E, Firment CS, Santra S. Endovascular surgery for proximal posterior inferior cerebellar artery aneurysms: an analysis of Glasgow Outcome Score by Hunt-Hess grades. Neurosurgery. 2006;58:619-625 [discussion: 619-625].
Journal homepage: www.WORLDNEUROSURGERY.org
Received 30 April 2018; accepted 14 June 2018 Citation: World Neurosurg. (2018) 117:e645-e652. https://doi.org/10.1016/j.wneu.2018.06.105
Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2018 Elsevier Inc. All rights reserved.
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2018.06.105
Coil Embolization Results of the Ruptured Proximal Posteriori Inferior Cerebellar Artery Aneurysm: A Single-Center 10 Years’ Experience Jonghoon Kim, Chulhoon Chang, Young Jin Jung
OBJECTIVE: To report a single-center experience with endovascular treatment of ruptured proximal posterior inferior cerebellar artery (PICA) aneurysms.
-
METHODS: Between January 2007 and December 2016, among 1403 patients with aneurysmal subarachnoid hemorrhage, 15 with ruptured proximal PICA aneurysms underwent endovascular embolization at our institution. Aneurysmal obliteration with a single microcatheter was performed in 9 patients. Additional microcatheter or stentassisted coil embolization was performed in 4 patients and parent artery occlusion in 2 patients.
aneurysm in the acute phase can be a good treatment modality with good patient outcomes.
-
RESULTS: Immediate angiographic results showed 10 complete occlusions (66.7%, 10/15). Five patients showed incomplete occlusion (remnant neck in 4 patients, remnant aneurysm in 1). Of those, 2 patients experienced recurrence and required conversion to microsurgical clipping. The remaining 2 patients remained in relatively stable condition. Procedure-related complications occurred in 3 patients (20%, with thromboembolic complications in 2 patients and intraprocedural rupture in 1). Clinical outcome was excellent: Glasgow Outcome Score 4 or 5 in 12 of 15 patients (80%). There was no rebleeding during follow-up.
-
CONCLUSIONS: Ruptured proximal PICA aneurysms may be effectively treated with endovascular coil embolization. A variety of coil embolization techniques are required to obliterate an aneurysm without parent artery occlusion. Given that recurrence is possible, follow-up is required. Surgical clipping can be performed for recurrence with a relatively low risk of complications, because the aneurysm is unruptured. Coil embolization of a proximal PICA
-
Key words Posterior inferior cerebellar artery - Subarachnoid hemorrhage -
Abbreviations and Acronyms GOS: Glasgow Outcome Scale PICA: Posterior inferior cerebellar artery
INTRODUCTION
P
osterior inferior cerebellar artery (PICA) aneurysms are rare and account for 0.5% to 3.0% of all intracranial aneurysms.1,2 Aneurysms arise from all segments of the PICA, but most originate from the vertebral arteryePICA junction and the proximal segment of the PICA. Direct surgical obliteration of these lesions in the acute phase is difficult because of the intimate relationship between the proximal PICA, the medulla, the lower cranial nerves (IX to XII), and important perforating branches and a large amount of subarachnoid hemorrhage make the surgical approach difficult. This limited surgical access has resulted in the consideration of endovascular coil embolization as an alternative and primary treatment modality for ruptured PICA aneurysms in the acute phase. However, endovascular coil embolization is not always easy and convenient. Aborted embolization can occur because of the relationship with the parent vessel and aneurysmal neck or a complex configuration. In these situations, various endovascular techniques are necessary for successful coil embolization. This study describes the clinical experience and technical pitfalls of coil embolization in patients with ruptured proximal PICA aneurysms. METHODS AND MATERIALS We retrospectively reviewed patients treated in our clinic for ruptured PICA aneurysms during the 10 years between January 2007 and December 2016. During this period, 10403 patients were admitted with aneurysmal subarachnoid hemorrhage, of whom 41
To whom correspondence should be addressed: Young Jin Jung, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2018) 117:e645-e652. https://doi.org/10.1016/j.wneu.2018.06.105 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2018 Elsevier Inc. All rights reserved.
Department of Neurosurgery, Yeungnam University Medical Center and Medical School, Namgu, Daegu, South Korea
WORLD NEUROSURGERY 117: e645-e652, SEPTEMBER 2018
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Table 1. Neurologic Deficits and Clinical Outcomes of Coil Embolization and Presence or Absence of Complications Year
Sex
Age
CC
HHG
FG
mFG
iGCS
WFNS
Neck
Height
Width
Location
Angiographic Outcome
Technique
Procedural Complications
Morbidity
Mortality
mRS 12 months
GOS 12 months
Recurrence
Additional Treatment
Remarks
1
2007
F
43
HA
2
2
2
14
2
2.80
4.00
3.80
VP junction
Remnant neck
Single MC
None
None
None
1
5
No
No
None
2
2007
F
44
HA
1
2
2
15
1
2.80
3.40
3.00
AMs
Complete
Double MC
None
None
None
1
5
No
No
None
3
2007
F
46
Drowsy
3
4
4
12
4
2.53
4.44
3.30
AMs
Remnant neck
Single MC
TEC
Infarction
None
2
4
No
No
Morbidity
4
2007
F
38
HA
2
4
4
14
2
3.41
3.82
4.54
AMs
Complete
Double MC
TEC
Expired
Expired
6
1
None
No
Mortality
5
2010
F
59
HA
2
3
2
14
2
2.72
5.35
4.58
VP junction
Remnant neck
Single MC
None
None
None
0
5
Yes, 4 years
Clipping
Recur
6
2012
F
34
HA
2
4
2
14
2
4.08
4.11
6.08
AMs
Complete
Double MC
None
None
None
0
5
Yes, 1 year
Clipping
Recur
7
2013
M
51
HA
2
4
4
14
2
2.20
2.26
2.26
AMs
Complete
Single MC
None
None
None
0
5
No
No
None
8
2013
F
43
HA
2
2
1
14
2
1.51
2.83
2.83
AMs
Remnant neck
Single MC
None
None
None
0
5
No
No
None
9
2013
F
85
HA
2
2
2
14
2
9.54
6.06
7.25
VP junction
Remnant aneurysm
SAC
None
None
Expired
6
1
None
No
Pneumonia
10
2014
F
28
HA
2
2
1
14
2
1.60
3.28
3.28
AMs
Complete
Single MC
None
None
None
0
5
No
No
None
11
2014
M
38
HA
2
2
2
14
2
NA
8.76
12.25
VP junction
Complete
PAO/double
None
None
None
0
5
No
No
None
12
2015
F
69
Stupor
2
4
4
6
5
1.48
2.21
2.21
AMs
Complete
Single MC
None
None
None
3
4
No
No
None
13
2015
F
53
Stupor
4
4
4
6
5
1.96
4.97
4.97
AMs
Complete
PAO/single
None
None
None
3
3
No
No
None
14
2016
F
51
HA
2
2
2
14
2
1.48
3.99
3.99
AMs
Complete
Single MC
None
None
None
0
5
No
No
None
15
2016
F
26
HA
1
2
2
15
1
2.92
2.92
4.50
AMs
Complete
Single MC
IPR
None
None
0
5
No
No
None
CC, chief complaint; FG, Fisher grade; mFG, modified Fisher grade; iGCS, initial Glasgow Coma Scale; WFNS, World Federation of Neurosurgical Societies grade; mRS, modified Rankin Scale; GOS, Glasgow Outcome Scale; HA, headache; VP, vertebroposterior inferior cerebellar artery; MC, microcatheter; AMs, anterior medullary segment; TEC, thromboembolic complication; PAO, parent artery occlusion; SAC, stent-assisted coiling; IPR, intraprocedural rupture; HHG, hunt hess grade.
ORIGINAL ARTICLE
COIL OF RUPTURED PICA ANEURYSM
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2018.06.105
Patient
ORIGINAL ARTICLE JONGHOON KIM ET AL.
had PICA aneurysms (2.92%, 41/1403). Of 27 patients (1.92%, 27/ 1403) received diagnoses of proximal PICA aneurysm, and 15 who underwent endovascular coil embolization were retrospectively analyzed. Eight patients (29.6%, 8/27) did not receive definitive treatment because their neurologic status was poor on arrival. Four patients underwent surgical clipping. All patients were treated by physicians specializing in neurologic intervention (J.K., C.C., and Y.J.J.). Patient sex, age, lesion location and size, neurologic grade, and radiologic findings on admission were analyzed. The presence or absence of complications associated with coil embolization and neurologic deficits and clinical outcomes were assessed (Table 1). Of 15 patients, 2 were men and 13 were women Their ages ranged from 26 to 85 years (mean standard deviation, 47.20 14.86 years). In 15 patients, SAH was observed on all initial noncontrast computed tomography. Twelve patients described having headache, 2 were stuporous, and 1 was drowsy but conscious. Hunt and Hess grade 1 was observed in 2 patients and grade 2 in 11 patients, grade 3 in 1, and grade 4 in 1. The mean aneurysm size was 4.13 1.62 mm.
Figure 1. Patient 7. Single microcatheter technique through the ipsilateral vertebral artery in a 51-year-old man with (A) diffuse subarachnoid hemorrhage and hydrocephalus. (B) Computed tomography angiographic view showing left proximal posterior inferior cerebellar artery aneurysm. (C) The aneurysm had a short height but a relatively wide neck
WORLD NEUROSURGERY 117: e645-e652, SEPTEMBER 2018
COIL OF RUPTURED PICA ANEURYSM
All patients underwent immediate coil obliteration on the day of rupture and were operated on under general or local anesthesia according to their neurologic status; 2 or 3 neurosurgeons participated in the coil embolization. RESULTS Aneurysmal obliteration with a single microcatheter alone was performed in 9 patients (Figures 1 and 2). Additional microcatheter or stent-assisted coil embolization was performed in 4 patients (Figure 3), and parent artery occlusion was performed in 2 patients (Figure 4). Immediate angiographic results showed 10 complete occlusions (66.7%, 10/15). Five patients showed incomplete occlusion (remnant neck in 4 patients, remnant aneurysm in 1). Of those, 2 patients experienced recurrence and required conversion to microsurgical clipping during follow-up. There was no rebleeding during a follow-up time of at least 12 months (Figure 5). No patients with incomplete coil embolization experienced rebleeding in the acute phase. Procedure-related
(neck/height/width, 4.31/3.29/4.61 mm). (D, E) The aneurysm grew in the direction of normal blood flow. Using a single lazy S-shaped microcatheter through the ipsilateral vertebral artery, the aneurysm was complete obliterated with multiple coils.
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COIL OF RUPTURED PICA ANEURYSM
Figure 2. Patient 12. Single microcatheter technique through the contralateral vertebral artery in a 69-year-old woman. (A) Non-contrast computed tomography showed diffuse subarachnoid hemorrhage with intraventricular hemorrhage. (B) Right vertebral angiography showed a small and elongated proximal posterior inferior cerebellar artery aneurysm.
complications occurred in 3 patients (20%), with thromboembolic complications in 2 patients and intraprocedural rupture in 1 (Figure 6). A noneprocedure-related complication (progressive pneumonia resulting in death) occurred in an 85-year-old woman. Clinical outcomes were excellent after 12 months: Glasgow Outcome Score 4 or 5 in 12 of 15 patients (80%). DISCUSSION Ruptured PICA aneurysms can be more difficult to treat and manage because of their relative rarity, deep surgical location, and proximity to important perforating vessels to the brainstem and lower cranial nerves. The PICA is divided into 1) anterior medullary, 2) lateral medullary, 3) tonsilomedullary, 4) telovelotonsilar, and 5) cortical segments, as well as proximal and distal segments. Proximal segments up to the anterior medullary segment and the segment after the lateral medullary segment can be classified as distal segments. Aneurysms occurring at the junction of the
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(neck/height/width, 2.42/3.99/2.32 mm). The aneurysm grew in a direction opposite that of blood flow. (C, D) We accessed the aneurysm through the contralateral vertebral artery. The contralateral approach was more stable, making it easier to deliver coils. (E, F) The aneurysmal sac was completely obliterated with multiple coils.
vertebral artery and the PICA or aneurysms in the anterior medullary segment are considered aneurysms in the proximal PICA, and those in the lateral segment are considered distal PICA aneurysms. Aneurysms can occur at any PICA segment. Depending on the segment, the relationship between the peripheral brainstem and lower cranial nerves may change, and the treatment plan may vary depending on where an aneurysm develops in a PICA segment. Proximal PICA aneurysms may be more difficult to treat if ruptured. This is because the PICA segment often has a meandering course, forming a very complex loop between the brainstem and the lower cranial nerves, and because vital vessels leading to the brainstem originate primarily from the proximal PICA. Because of these anatomic limitations, there can be a large amount of hematoma in the subarachnoid space in the acute phase, making microsurgical clipping very difficult because of difficulty securing vision and because the boundary with surrounding critical structures is poorly defined. The PICA gives rise to perforating branches to the medullar, choroidal, and cortical
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2018.06.105
ORIGINAL ARTICLE JONGHOON KIM ET AL.
Figure 3. Patient 6. Double microcatheter technique for wide neck or incorporated branch aneurysm in a 34-year-old woman. (A) Three-dimensional rotational digital subtraction angiography showed a proximal posterior inferior cerebellar artery aneurysm, which completely invaded the parent artery (neck/height/width, 4.08/4.11/6.08 mm). (B, C)
arteries. The perforating arteries are small and arise from proximal segments and terminate in the brainstem.3 As noted, it is important to treat proximal PICA aneurysms without damaging the surrounding lower cranial nerves and small blood vessels that feed the brainstem, so as to prevent surgery-related complications. However, surgical treatment of these lesions is very difficult, and the results may be poor. According to several reports, a new neurologic deficit occurs with an incidence of 20% to 60% after surgical clipping.4-8 Al-khayat et al.4 reported good outcomes in 68.2% of patients (15/32 with GOS 1 or 2) but lower cranial nerve palsy in 71.9% (23/32) of patients who had ruptured proximal PICA aneurysms. Singh et al.8 reported a 30% incidence of complications (6/20) and mortality rate of 15% (3/ 20) after surgical treatment of 20 ruptured PICA aneurysms. Thus, surgical treatment is known to be extremely difficult. However, endovascular treatment has shown good outcomes for these lesions. Inasmuch as microsurgical treatment in the acute phase is very difficult, delayed surgery may be required in some
WORLD NEUROSURGERY 117: e645-e652, SEPTEMBER 2018
COIL OF RUPTURED PICA ANEURYSM
Two microcatheters (Preshaped 90 and J, Excelsior SL-10 microcatheter, Stryker, Kalamazoo, Michigan, USA) were used to make frame coils. (D) Two coils were used to perform embolization while maintaining patency of the parent artery. (E) The aneurysm was nearly completely obliterated.
cases. Viswanathan et al.9 reported the surgical outcomes in 27 patients with ruptured PICA aneurysms. Ten patients underwent semi-urgent surgery between 2 and 5 days after stroke, and 17 underwent surgery more than 5 days after bleeding. Singh et al.8 reported that the operation proceeded after 32 days (mean) after ictus (range, 3 to 173 days). The development of therapeutic devices and endovascular coil techniques has made treatment of these lesions possible.10 Miricle et al.11 reported a good outcome (GOS 1 or 2) in 68% of patients (31%) with a ruptured PICA aneurysm, with a procedure-related complication rate of 6.5% (2/31). Xu et al.2 reported complication and mortality rates of 11.1% (4/36) and 2.8% in 36 patients, respectively. Gupta et al.12 reported 13 patients with ruptured proximal PICA aneurysm with complete coil occlusion in 84.6% (11/13) without intraoperative rupture, although coil loop migration occurred in 2 patients (4.61%). Of 20 patients who underwent endovascular treatment reported by Song et al.,13 2 (10%, 2/20) had an intraoperatiave rupture and 2 had
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ORIGINAL ARTICLE JONGHOON KIM ET AL.
COIL OF RUPTURED PICA ANEURYSM
Figure 4. Patient 11. Parent artery occlusion in a 38-year-old man with subarachnoid hemorrhage and intraventricular hemorrhage (A). Three-dimensional rotational digital subtraction angiography showed a fusiform aneurysm with the posterior inferior cerebellar artery originating from the sac (B). The aneurysm was completely obliterated with parent
artery occlusion (C). Fortunately, the posterior inferior cerebellar artery was supplied via muscular branch anastomosis (D). Follow-up diffusion-weighted magnetic resonance imaging showed no definite infarction (E). The patient was discharged without neurologic deficits.
Figure 5. Patient 6. Recurrence in a 35-year-old woman and conversion to clipping. Coil compaction occurred 12 months after embolization of a ruptured proximal posterior inferior cerebellar artery aneurysm. (A) The aneurysm height was too short to permit recoiling (neck/height/width,
3.92/1.41/3.32 mm). (B) The surgical field was clear and the lower cranial nerves were clearly visible. (C) Postoperative three-dimensional rotational digital subtraction angiography showed complete obliteration of the aneurysm.
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WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2018.06.105
ORIGINAL ARTICLE JONGHOON KIM ET AL.
Figure 6. Patient 4. Complicated case in a 38-year-old woman with subarachnoid hemorrhage and intraventricular hemorrhage (A). Three-dimensional rotational digital subtraction angiography showed a proximal posterior inferior cerebellar artery aneurysm with a relatively narrow neck (B). Using double microcatheter technique, the aneurysm
thromboembolic complications (10%, 2/20), but 70% had good outcomes. Endovascular treatment seemed to have more favorable clinical outcomes: modified Rankin scale, 0 to 2; mean modified Rankin Scale, 1.75 for endovascular treatment versus 3.50 for surgery (P ¼ 0.152).13 Cho et al.14 reported excellent results; 10 patients were treated with coil embolization without complications. Our study was limited to the proximal PICA segment. This region is associated with the vertebral artery and important perforating arteries to the brainstem, but the study showed good results with an acceptable complication rate despite the difficulty of coiling while saving the parent artery and small perforators. Moreover, we were able to perform endovascular coil embolization the day the rupture occurred. Although the lesion location was uncommon and the lesions were diverse and invaded peripheral blood vessels, embolization using various coiling techniques and instruments was feasible. In addition, there was no acute rebleeding after coil embolization, and secondary surgical clipping was possible without late complications after recurrence.
WORLD NEUROSURGERY 117: e645-e652, SEPTEMBER 2018
COIL OF RUPTURED PICA ANEURYSM
was completely obliterated (C). However, the lateral angiographic image obtained after coiling showed some thrombus in the vertebral artery (D). Diffusion-weighted magnetic resonance imaging showed multiple infarctions in the bilateral cerebellum (E).
This study has some limitations. This was a retrospective study in which no randomization was performed. Therefore, the patient age range was limited, and there was no one-to-one comparison with surgical treatment because only the results of intravascular surgery were assessed. In addition, given that the number of patients was small, it is unclear whether these results were representative of all possible ruptured proximal PICA aneurysms. CONCLUSIONS Using microcatheters, microwires, coils, and other materials, we have been able to perform coil embolization more easily and safely. The initial treatment for a ruptured proximal PICA aneurysm is shifting from surgical clipping to endovascular obliteration. Coil embolization of an acute-phase ruptured proximal PICA aneurysm can be carried out relatively safely and has good results. Although recurrence is possible during follow-up, there was no rebleeding in the acute phase. Therefore, even after recurrence, a secondary operation can be performed with a lower risk of
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COIL OF RUPTURED PICA ANEURYSM
complications because the aneurysm is unruptured. A ruptured proximal PICA aneurysm is very rare and difficult to treat and
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often presents with varied morphology. However, coil embolization may become a useful and promising option for treatment.
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12. Gupta V, Mulimani N, Kumar A, Ahuja C, Mathuria SN, Khandelwal N. Endovascular treatment of ruptured proximal PICA aneurysms: a single-center 5-years experience. Neurol India. 2014; 62:269-275. 13. Song J, Park JE, Chung J, Lim YC, Shin YS. Treatment strategies of ruptured posterior inferior cerebellar artery aneurysm according to its segment. Surg Neurol Int. 2017;8:155. 14. Cho KC, Kim Y, Suh S, Joo J, Hong CK. Multidisciplinary management for the treatment of proximal posterior inferior cerebellar artery aneurysms. Neurol Res. 2017;39:403-413.
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Conflict of interest statement: This work was supported by the 2014 Yeungnam University Research Grant.
11. Mericle RA, Reig AS, Burry MV, Eskioglu E, Firment CS, Santra S. Endovascular surgery for proximal posterior inferior cerebellar artery aneurysms: an analysis of Glasgow Outcome Score by Hunt-Hess grades. Neurosurgery. 2006;58:619-625 [discussion: 619-625].
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Received 30 April 2018; accepted 14 June 2018 Citation: World Neurosurg. (2018) 117:e645-e652. https://doi.org/10.1016/j.wneu.2018.06.105
Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2018 Elsevier Inc. All rights reserved.
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2018.06.105