Microsurgery for intracranial arteriovenous malformation: Long-term outcomes in 445 patients.
BACKGROUND
The management of intracranial arteriovenous malformations(AVMs) poses challenges to the cerebrovascular specialists.


OBJECTIVE
To review the long-term outcomes of intracranial AVMs treated with microsurgical resections.


METHODS
We performed a retrospective review of 445 patients with intracranial AVMs treated in our hospital from January 1st, 2008 to December 31st, 2014. The extracted data included demographic characteristics, clinical presentations, Spetzler-Martin (SM) grades, Supplemented Spetzler-Martin (SM-Supp) Grades, treatment modalities, long-term outcomes, and obliteration rates. Outcome was assessed with a post-operative modified Rankin Scale (mRS) score at the last follow-up visit.


RESULTS
Of the 445 patients treated with microsurgery, 298 (67.0%) patients initially presented with hemorrhage. Based on the SM grading system, the patients were graded as follows: 83(18.6%) Grade I, 156(35.1%) Grade II, 132(29.7%) Grade III, 61(13.7%) Grade IV and 13(2.9%) Grade V. Overall, 344(77.3%) patients had a favorable outcome (mRS score of 0-2). The favorable outcome for Grade I and II were 92.8% and 85.9%, respectively, sharply reducing to 52.5% in patients with Grade IV and 15.4% in patients with Grade V AVMs. 388(87.2%) patients achieved complete obliteration of the AVMs. 63(14.2%) patients experienced recurrent hemorrhage, and the frequency of rehemorrhage was highest in Grade V patients (77.0%), dropping to 3.6% and 3.8% in patients with Grade I and II lesions, respectively. Permanent neurological deficits occurred in 66(14.8%) patients and death in 35(7.9%) patients. There was no difference of AUROC values between SM grading system and SM-supp grading system (0.726 and 0.734, respectively, p = .715).


CONCLUSIONS
The Spetzler-Martin grading system is a simple and effective method to estimate the risk of surgery and to evaluate the prognosis. Microsurgical resection for AVMs depends on the SM grades, and the morbidity-mortality rate increases with an increasing SM grade.
Department of Neurosurgery, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, People's Republic of China.
Qingqing
http://orcid.org/0000-0003-3273-7544
Q
Ren
Department of Neurosurgery, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, People's Republic of China.
Min
M
He
Department of Neurosurgery, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, People's Republic of China.
Yunhui
Y
Zeng
Department of Neurosurgery, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, People's Republic of China.
Zhiyong
Z
Liu
Department of Neurosurgery, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, People's Republic of China.
Hao
H
Liu
Department of Neurosurgery, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, People's Republic of China.
Jianguo
J
Xu
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy / Q000379:methods*; D004621:Embolization, Therapeutic / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006470:Hemorrhage / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D007223:Infant; D002538:Intracranial Arteriovenous Malformations / Q000401:mortality* / Q000601:surgery*; D008297:Male; D008866:Microsurgery / Q000379:methods*; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D016634:Radiosurgery / Q000379:methods; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult