AVM ( 動靜脈畸形 ) 之外科療法 神經外科 謝宗哲醫師

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1 AVM ( 動靜脈畸形 ) 之外科療法 神經外科 謝宗哲醫師

2 Arteriovenous malformation Brain parenchymal malformation Dural malformation

3 Surgical Management of Cerebral Arteriovenous Malformation

4 病理機轉 Congenital 先天性 98% solitary Dilated arteries and vein without capillary bed May contain gliotic brain, hemorrhagic residua Flow related aneurysm in 10-12% 12%

5 位置 85% supratentorial 15% posterior fossa

6 好發年齡 Peak between 20 and 40 years 25% in 兒童 / 青少年

7 症狀 Hemorrhage 50% with 2% to 4%/year cumulative risk Each bleeding 30% risk of death, 25% risk of long-term morbidity Seizure( 癲癇 ) 25% Mass effect, H/A, vascular steal phenomena, focal neurological deficit

8 AVM 破裂風險因子 Small AVM Central(deep) ) venous drainage pattern Single draining vein Peri- or intraventricular location Intranidal aneurysm

9 治療方式 1. Endovascular embolization ( 栓塞 ) 2. Neurosurgical resection ( 開刀 ) 3. Radiosurgery ( 放射手術 )

10 Embolization ( 栓塞療法 ) Completely obliterated by embolization solely: 10% A bit of AVM remains after embolization,, the risk of hemorrhage remains high

11 栓塞目標 Preop embolization ( 開刀手術前栓塞 ) for final neurosurgical resection: Focusing on botton feeders occlusion Preop embolization ( 放射手術前栓塞 ) for final Radiosurgery: Focusing on volume reduction ( 減少體積 )

12 栓塞風險 Death: 1-2% 1 Severe deficit: 1.5% Mild deficit: 9% Transient deficit: 11% 1st time hemorrhage after E/Z: 3% Rebleeding after E/Z: 7% New seizure: 3%

13 放射手術 Nidus smaller than 3cm 2yrs or longer to obliterate the lesion <1cm: 90% <3cm: 80% >3cm: 30%

14 放射手術之機轉 The gradual occlusion of nidus is attributed to endothelial damage in pathological arteries (proliferation of smooth-muscle muscle cells and elaboration of extracellular collagen), and leads to progressive stenosis and obliteration of the AVM

15 Spetzler and Martin grading Diameter: <3cm(1), 3-6cm(2), 3 >3cm(3) Location: eloquent(1), noneloquent(0) Deep venous drain: yes(1), no(0) Sum: progressive operative difficulty

16 Surgical outcome by Spetzler- Martin grade Grade No deficit minor D. Major D % 2 95% 5% 3 84% 12% 4% 4 73% 20% 7% 5 69% 19% 12%

17 治療考量因素 Associated aneurysms Flow: high or low Age History of previous hemorrhage Size, location and compactness of nidus Availability of interventionalist General medical condition of patient

18 Surgical Management of Dural Arteriovenous Malformation

19 臨床表現 Aggressive CT presentation: 1. Hemorrhage 2. Headache/dizziness 3. Brain swelling Nonaggressive 1.Tinnitus /Bruit 2.Infarct Clinical presentation: 1. Neurologic deficit 2. Cons. change / Dementia 3. Seizure 4. IICP

20 Djindjian and Merland (1978) Gr.I : drain into sinus with normal direction of flow Gr.II : drain into sinus with reflux into cortical veins or other sinuses IIa : reflux into other sinuses IIb : reflux into cortical veins IIa+b : reflux into other sinuses and cortical veins Gr.III : drain into cortical veins directly Gr.IV : drain into cortical veins with aneurysmal dilatation Gr.V : drain into spinal canal

21 治療適應症 1. Aggressive presentation 2. Intractable non-aggressive presentation 3. Leptomeningeal venous drainage 4. (type IIb, IIa+b,, III, IV, V)

22 治療方式 Expectant Endovascular embolization arterial Venous Neurosurgery Radiosurgery

23 治療考量因素 Nature course( 自然病程 ) Treatment safety( 安全性 ) Treatment efficacy( 有效性 ) Treatment complexity( 複雜性 )

24 Nature Course Spontaneous regression : cavernous sinus transverse- sigmoid More benign course: venous drainage type I type IIa

25 Treatment Safety How is the cerebral venous outflow? Diseased sinus can be sacrified safely? Comparing the mortality / morbidity rates in various therapeutic modalities.

26 Treatment Efficacy Palliative or definitive? Comparing the cure rate in various management modalities.

27 Treatment Complexity More complicated for neurosurgery when dural AVMs involving torcular,, jugular bulb. Smaller feeders are much more difficult to deal with using endovascular method, such as meningohypophyseal artery

28 開刀預後不良之因素 1. Venous drainage : II b II a+b 2. Location: S.S.S. Torcular T.S./S.S. 3. Presentation : Infarct Conscious change

29 Type I Type IIa Type IIb IIc III IV V Torcular, Jugular blub Expectant Intractable syndrome Endovascular Neurosurgery may be combined with radiosurgery

30 Surgical Management of Aneurysm Rupture with SAH (Spontaneous Subarachnoid Hemorrhage)

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32 Presentation Sudden onset, explosive, unexperienced headache Neck stiffness

33 aneurysm

34 Surgical Timing? Neurosurgeons used to defer operation until two weeks later. Nevertheless, more and more neurosurgeons have changed the policy and operated on these cases earlier for the main reason of preventing rebleeding.

35 Outcome G MD SD V D 60% 15% 7% 6% 12% Favourable 75% Unfavourable 25% 401 aneurysm surgerys were performed in 364 patients during a 4-year period in our institute.

36 Surgical Timing v.s. Outcome 3 d Surgical timing Favourable 67% Outcome Unfavourable 33% 4-13 d 14 d 84% 75% 16% 25%

37 Outcome of Poor Grade Patients Outcome Pt no Favourable Unfavourable Hunt Gr IV,V 58 34% 66% Hunt Gr IV,V (early op) 31 35% 65% Hunt Gr V 3 0% 100%

38 Recommendations for Surgical Treatment of Aneurysmal SAH Hunt GrI-IV IV: Surgery can be done earlier if there is no evidence of vasospasm nor severe brain swelling. Hunt GrV: Relative contraindication for aneurysm surgery, except drainage of CSF for dilated ventricle. Patients with poor general condition,, aneurysms with difficult location,, and extremely elderly patients may be proposed for endovascular treatment.

39 Surgical Management of Carotid Stenosis

40 Surgical Indication Symptomatic: TIA, minor stroke, others Stenosis: : 70% or greater Asymptomatic Stenosis: : 80% or greater

41 Which Is a Contraindication for Carotid Endarterectomy? Carotid occlusion Contralateral stenosis or occlusion Tandem stenosis Carotid stenosis with aneurysm

42 From April 1994 to December 2001, there were 134 carotid endarterectomies performed in 129 patients.

43 Clinical Presentation 1. TIA : 30.9% 2. Stroke : 67.4% 3. Asymptomatic : 1.7%

44 Diagnosis 1. Carotid duplex 2. Angiography Carotid duplex Degree of stenosis: 70% or greater in all pts Level of stenosis: midportion of C2 down to upper portion of C6 DSA

45 Operation 1. General anesthesia 2. Monitoring : EEG SSEP 3. Shunting : depend on monitor findings (1 art.) 4. Closure : primary (131 art.) Gortex patch (2 art.) Saphenous vein patch (1 art.)

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48 Surgical Results Surgical mortality : 0 Surgical complications: Perioperative storke : 2 ( 1.5%) Wound hematoma : 2 ( 1.5%) Intracerebral hematoma : 1 ( 0.7%)

49 Clinical Follow-up Expired : 5 pts 1. Sepsis : 2 (4 and 33 M later) 2. Heart disease: 2 (2 and 24 M later) 3. Cancer (cholangiocarcinoma( cholangiocarcinoma) ) : 1 (11 M later) Late TIA : 1 pt 7 months later Late stroke : 0

50 Carotid Duplex Follow-up 4 pts ( 5.2%) Restenosis Symptomatic (TIA): 1 (1.3%) Asymptomatic : 3 (3.9%) All were found in 1 year after surgery a)1 1 month: 1 b)6 6 months: 2 c) 12 months: 1

51 From our surgical experiences, the carotid endarterectomy seems to be beneficial in the prevention of stroke with acceptable surgical mortality and morbidity rates Surgical mortality : Perioperative stroke : Late stroke : 0 1.5% 0 (relating to surgically treated carotid artery) Late TIA : 0.7%