1. Department of Neuroendovascular Therapy, Kohnan Hospital, Sendai, Japan Ryushi Kondo, Yasushi Matsumoto Department of Neurosurgery, Kohnan Hospital Satoru Fujiwara Department of Neuroendovascular Therapy, Tohoku University School of Medicine Hiroaki Shimizu, Akira Takahashi Department of Neurosurgery, Tohoku University School of Medicine Teiji Tominaga Stent Placement for Intracranial Internal Carotid Artery Dissection Presenting with Ischemic Stroke

2. Intracranial ICA dissection presenting with ischemic stroke Reported cases are limited. Natural course is poorly understood. Optimal treatment remains controversial. Conservative treatment STA-MCA anastomosis Stent placement

3. Almost reported cases are received conservative treatment. The condition of some patients can rapidly deteriorate during conservative treatment. Conservative treatment

4. Deterioration during conservative treatment 11-year-old Female Day 0 (right ICA dissection) Day 8 (Progression of stenosis)

5. STA-MCA anastomosis Cerebral low perfusion strongly associated with the neurological deterioration. STA-MCA bypass surgery during the acute stage has been recommended. Only two successful cases have been reported.

6. Difficulty of STA-MCA anastomosis Selecting candidate patients for surgery Determining the optimal timing for surgery Time-consuming

7. Various clinical courses Oka F, et al: Surg Neurol 2008: 578-585 Clinical courses A : single attack / severe outcome B : single attack / mild to moderate outcome C : recurrent attacks / various outcomes A : n=11 B : n=12 C : n=10 Unclassified : n=12

8. Candidate patients for bypass surgery Rapid deterioration after mild onset Recurrent attacks

9. Unsuccessful surgical anastomosis 14-year-old Female Right ICA dissection GCS13 (E3V4M6) Left hemiparesis Oka F, et al: Surg Neurol 2008: 578-585

10. Clinical course Day 0Day 10Day 4 R t. Severe headache GCS13 (E3V4M6) Moderate left hemiparesis Symptoms disappeared MRA : Spontaneous resolution SPECT : Hyperperfusion Second severe headache Left hemiparesis rapidly deteriorated MRA : Aggravation of stenosis DWI : Enlargement of infarction Oka F, et al: Surg Neurol 2008: 578-585

11. STA-MCA anastomosis was attempted 1.5 hours after the recurrent attack Day 0Day 10Day 4 R t. Severe headache GCS13 (E3V4M6) Moderate left hemiparesis Symptoms disappeared MRA : Spontaneous resolution SPECT : Hyperperfusion Second severe headache Left hemiparesis rapidly deteriorated MRA : Aggravation of stenosis DWI : Enlargement of infarction Oka F, et al: Surg Neurol 2008: 578-585

12. Dissection and thrombus extended from ICA to M4 Ｍ２Ｍ２ Ｍ１Ｍ１ ICA: normal segment ICA: dissection Pcom a. M1: dissection Bypass was not possible Oka F, et al: Surg Neurol 2008: 578-585

13. Extended infarction Day 13

14. Stent Placement for intracranial ICA dissection Preferred interventional option Reported cases are limited Long-term outcome is unclear

15. Summary of stenting cases Age / Sex Cause of Stenting Follow-up (months) Clinical outcomes Angiographical outcomes Dissecting segment Restenosis 128 / M Rapid deterioration 24mRS 2Healingno 229 / F Recurrent attack 28mRS 1Healingno 317 / M Rapid deterioration 6mRS 2Healingno

16. Present Illness Sudden severe headache while watching TV Weakness of left extremities 1 hour after a onset of headache Neurological Examinations GCS13 (E3M4V6) Mild left hemiparesis Left hemineglect Clinical Course Left hemiparesis rapidly deteriorated, leading to complete hemiplegia 2 hours after onset. Case 1 : 28-year-old Male

17. DWI : 2 hours after onset

18. AP view Left oblique view Right internal carotid angiogram

19. MicroDriver 2.5x12 mm (9atm-2.5mm) Stent placement : 4 hours after onset

20. 2 years after procedure Immediately after procedure Follow-up angiogram

21. 2 years after procedure Mild weakness of left hand Left hemianopsia NIHSS 2 mRS 2

22. Discussion Intracranial ICA dissection can cause unexpected and rapid aggravation of patient’s condition. It is difficult to identify the appropriate candidate patients for bypass surgery before neurological deterioration. STA-MCA anastomosis sometimes cannot be applied in cases involving a rapid deterioration of cerebral ischemia.

23. Stent placement can be performed immediately compared to bypass surgery. Our small case series suggests satisfactory mid- term outcome. The long-term efficacy and durability of stent remain to be determined in larger series. It is believed self-expandable stent designed for intracranial artery is safer. Discussion

24. Conclusion Stent placement should be considered as revascularization procedure for intracranial ICA dissections when conservative treatment is not effective.