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MINISTRY OF EDUCATION AND TRANING MINISTRY OF NATIONAL DEFENCE 108 INSTITUTE OF CLINICAL MEDICAL AND PHARMACEUTICAL SCIENCES NGUYEN VAN PHUONG STUDY ON CLINICAL CHARACTERISTICS, COMPUTED TOMOGRAPHY IM.

108 INSTITUTE OF CLINICAL MEDICAL AND

PHARMACEUTICAL SCIENCES

NGUYEN VAN PHUONG

STUDY ON CLINICAL CHARACTERISTICS, COMPUTED TOMOGRAPHY IMAGING AND EFFICIENCY OF MECHANICAL THROMBECTOMY

IN PATIENTS WITH ACUTE ISCHEMIC STROKE

SPECIALIZED : ANESTHETICS AND RESUSCITATION CODE : 62.72.01.22

THE SUMMARY OF MEDICAL PHILOSOPHIC THESIS

Ha Noi - 2019

THIS STUDY HAD BEEN IMPLEMENTED IN THE 108 INSTITUTE

OF CLINICAL MEDICAL AND PHARMACEUTICAL SCIENCES

The supervisors:

Associate Professor Ph.D TRAN DUY ANH

Associate Professor Ph.D LE VAN TRUONG

Can find full text document of this thesis in:

National Library

108 Institute of Clinical Medical and Pharmaceutical Sciences Library

.INTRODUCTION

Stroke is the third cause

of death and the leading cause of serious, long-term disability In which, the ischemic stroke accounts for almost 80% of the total cases of strokes Large vessel occlusion stroke had severe clinical events and causes high disability rates Mechanical thrombectomy has been approved by American Heart Association/American Stroke Association with level IA in 2015 as standard treatment for acute anterior circulation stroke due to occlusions of the internal carotid artery (ICA) or the M1 segment of the middle cerebral artery (MCA) and improvement of functional independence compared with standard medical care

However, the selection of patients with acute ischemic stroke (AIS) are appropriate, whoes are still difficult, especially in many stroke centers in Viet Nam So that the study on clinical characteristics and computerized tomography imaging of AIS patients due to large cerebral vessels occlusion were necessary and meaningful in clinical practice The effectiveness of mechanical

revascularization, which were reported on many international studies,

but there are not many in Vietnam From that fact, we performed " Study on clinical characteristics, computed tomography imaging and efficiency of mechanical thrombectomy in patients with acute ischemic stroke", the thesis had two main purposes:

1 Clinical characteristics, computed tomography imaging of acute ischemic stroke due to large vessel of the anterior cerebral artery system occlusion have been had endovascular mechanical revascularization

2 Evaluated the effectiveness and safety of the

endovascular mechanical revascularization method to treated acute

ischemic strokes due to large vessel of the anterior cerebral artery system occlusion

THE NEW POINTS OF THESIS

- The research results provide data on clinical characteristics and computed tomography imaging of acute ischemic stroke due to large vessel of the anterior cerebral artery system occlusion

- The effectiveness of the endovascular mechanical revascularization method to treated acute ischemic strokes due to large vessel in

Vietnam

- Understand the influence factors on good outcome and mortality after mechanical thrombectomy in patients with acute large vessel occlusion stroke

THE STRUCTURE OF THESIS

The thesis consists of 116 pages, including the questions (2 pages), the overview (36 pages), the subjects and methods (19 pages), the research results (25 pages), the discussions (31 pages), the conclusions (2 pages) and the recommendations (1 page)

There are 31 tables, 16 charts, 2 graph and 13 figures The reference has 19 Vietnamese and 131 foreign references

Five articles related to the subject have been published

ABBREVIATIONS

AIS: Acute ischemic stroke CT: computed tomography

ASPECTS: Alberta Stroke Program Early Computed Tomography Score CTA: computed tomography angiography

ICA: internal carotid artery LVO: large vessel occlusion MCA: middle cerebral artery MT: Mechanical thrombectomy mRS: modified Rankin scale n: Number of patients

NIHSS: The National Institutes of Health Stroke Scale

TICI: The thrombolysis in cerebral infarction

CHAPTER 1 – OVERVIEW 1.1 Diagnosis of ischemic stroke

1.1.1 Clinical diagnosis of ischemic stroke

The clinical symptoms of AIS were very diverse, they depend on the location of the infaction, but there were the following common clinical symptoms: Paralysis, facial paralysis, language disorders, visual disturbances, double vision, forced gaze deviation In addition, there were also sensory disorders, and unconscious

The National Institutes of Health Stroke Scale (NIHSS) is a tool used by healthcare providers to objectively quantify the impairment

which scores a specific ability between 0 and 4 For each item, a score of 0 typically indicates normal function in that specific ability, while a higher score is indicative of some level of impairment The individual scores from each item are summed in order to calculate a patient's total NIHSS score The maximum possible score is 42, with the minimum score is 0

1.1.2 Clinical diagnosis of the location of acute ischemic stroke due to large vessel of the anterior cerebral artery system

The cortical signs such as aphasia and neglect are sensitive indicators for large vessel occlusion (LVO) stroke

Middle cerebral artery (MCA) occlusion stroke had signs: aphasia, neglect, motor deficits, loss of sensation in any part of the body and Conjugate Eye Deviation (CED -prévost's sign)

Internal carotid artery (ICA) occlusion stroke, there are manifestations of MCA occlusion stroke signs and anterior cerebral artery (ACA) occlusion stroke signs

1.1.3 Computerized tomography diagnosis of acute ischemic stroke

Non-contrast computed tomography (NCCT) remains a widely used imaging technique and plays an important role in the evaluation

of patients with acute ischaemic stroke NCCT had helped identify early ischemic changes signs include changes in brain parenchyma that reflect either decreased attenuation (eg, loss of definition of the lentiform nucleus) or tissue swelling (eg, hemispheric sulcal effacement, effacement of the lateral ventricle) Systematic approaches to recognition of early ischemic changes such as the

Alberta Stroke Program Early CT Score (ASPECTS) system improve the detection of early ischemic changes

Computed tomography angiography (CTA) uses an injection of contrast material into your blood vessels and CT scanning to help diagnose and evaluate blood vessel disease or related conditions, such as aneurysms or blockages In thesis, CTA helped determining

the occlusive of cerebral location, collateral flow

1.2 Endovascular mechanical revascularization method to

treated acute ischemic strokes due to large vessel occlusion

1.2.1 Mechanical thrombectomy systems

- The first generation with Merci (Merci Retrieval System) device of Concentric Medical and Penumbra system (Penumbra system) of Penumbra Inc

- The second generation has stent Solitaire (Solitaire FR stentriever)

of Covidien, stent Trevo (Trevo ProVue stentriever) of the Stryker company and A Direct Aspiration First Pass Technique (ADAPT) of Penumbra Inc

1.2.2 Complications of endovascular mechanical revascularization

- Complications related to contrast drugs: hypersensitivity reactions, acute kidney injury

- Complications related to the intervention process: intracranial haemorrhage, cerebral arterial dissection, embolization to new or target vessel territory, access-site problems, reocclusion after thrombectomy

- Complications related to the process of care and treatment

1.2.3 Studies on endovascular mechanical revascularization to treated acute ischemic strokes due to large vessel occlusion

- In the world, typical and famous were 5 studies using mechanical thrombectomy of 2nd generation, showing high revascularization rate (up to 88%), patients with good neurological outcomes from 45 to 72%, windows treatment is extended 6-8 hours There were trial

including MR CLEAN, ESCAPE, SWIFT PRIME, EXTEND-IA, REVASCAT

- In Vietnam, studies at Bach Mai Hospital, Ho Chi Minh City University of Medicine and Pharmacy, People's Hospital 115, 108 Military Central Hospital reported results of revusculation from 71 to 89% and results good neurological recovery from 42 to 63%

CHAPTER 2 SUBJECTS AND METHODS 2.1 Subjects

- Patients with acute ischemic stroke were examined and treated at the 108 Military Central Hospital

- Study time: from June 2016 to March 2018

2.1.1 Criteria for selecting patients

- Criteria for diagnosis of acute ischemic stroke due to large vessel occlusion:

+ Clinically (based on WHO): sudden facial drooping, sudden arm weakness, sudden speech difficulties

+ Used noncontrast CT scan was taken to exclude presence of intracranial hermorrhage, determine ASPECTS score

+ Used CTA to identify located artery occlusion The large

vessel include: internal carotid artery, middle cerebral artery

(segment M1, M2)

- Criteria for selecting patients to apply mechanical thrombectomy based on 2018 guidelines for management of acute ischemic stroke of

American Heart Association/American Stroke Association: (1)

prestroke mRS score of 0 to 1; (2) causative occlusion of the internal carotid artery or MCA segment 1 or 2 (M1, M2); (3) age ≥18 years; (4) NIHSS score of ≥6; (5) treatment can be initiated (groin puncture) within 6 hours of symptom onset and (6) relatives of patients agree to apply the technique and participate in study

2.1.2 Criteria for exclusion of patients

Relative contraindications follow the 2018 guidelines for

management of acute ischemic stroke of American Heart Association/American Stroke Association:

- Patients with severe systemic diseases such as liver failure, severe renal failure, coagulopathy, late stage cancer

- There was history of allergy contrast drug

- History of severe head trauma, myocardial infarction or cranial surgery in the last 3 months

- Risk of high bleeding: platelet count <100,000/mm3; treatment of recent anticoagulants at INR ≥ 3.0; use heparin within 48 hours and activated partial thromboplastin time (APTT)> 2 times normal

2.2 Material and ethods

p = (p1 + p2)/2 p1 = 0.36: the rate of patients with good neurological recovery (mRS: 0-2) after 90 days when apply mechanical thrombectomy with MERCI, in the Multi-MERCI study was 36%;

p2 = 0.59: The proportion of patients with good neurological recovery results after 90 days, in ADAPT study was 59% in the study

0 point ……… No stroke symptoms

1-4 points ………… Minor stroke

5-15 points ………… Moderate stroke

16-20 points ……… Moderate to severe stroke

21-42 points …………Severe stroke

2.3.1.2 Evaluate the results of computed tomography images

- Early signs of ischemic stroke on nonconstrast CT scan

+ The hyperdense artery sign: caused by new blood clots in the vessels, often observed in the middle cerebral artery

+ Hypoattennuating brain tisue including: cortical sulcal effacement, loss of the insular ribbon, obscuration of the lentiform nucleus, loss of gray-white matter differentiation in the basal ganglia

- Evaluating ASPECTS score on noncontrast CT Alberta Stroke Program Early CT score (ASPECTS) is a 10-point quantitative score used to assess early ischemic changes on non-contrast CT head ASPECTS is intended to provide a reliable and reproducible grading system on non-contrast CT examinations of the head for detection of early ischemic changes in patients suspected of having acute large vessel anterior circulation occlusion

- Determine the location of occlusion vessel on CTA: where the contrast drug does not pass or pass less than the opposite side, which

is the obstruction or narrowing of the artery

- Collaterals and clot burden were determined on baseline CTA The collateral score grades distal arteries filling with a 4-point scale with (+) 0 constituting absent collaterals (0% filling of the occluded territory), (+) 1 for poor collaterals (>0% and ≤50% filling of the occluded territory), (+) 2 for moderate collaterals (>50% and <100% filling of the occluded territory), and (+) 3 for good collaterals (100% filling of the occluded territory)

- Evaluate the collaterals flow scale on digital subtraction

angiography (DSA) based on the guidance of the Neurological Intervention Association/American Radiology Associates (+) Grade

0: No collaterals visible to the ischemic site (+) Grade 1: Slow collaterals to the periphery of the ischemic site with persistence of some of the defect (+) Grade 2: Rapid collaterals to the periphery of ischemic site with persistence of some of the defect and to only a portion of the ischemic territory (+) Grade 3: Collaterals with slow but complete angiographic blood flow of the ischemic bed by the late venous phase (+) Grade 4: Complete and rapid collateral blood flow

to the vascular bed in the entire ischemic territory by retrograde perfusion

2.3.2 Purpose 2

2.3.2.1 Evaluate the effectiveness of endovascular recanalization

- Evaluate the effectiveness of reperfusion after mechanical thrombectomy according to modified TICI classification (modifiel Thrombolysis in cerebral infarction score - mTICI) Good reperfusion (mTICI 2b - 3) Bad reperfusion or there is no reperfusion (mTICI

<2b)

- The reocclusion was the status of previous good reperfusion (mTICI 2b-3), but the results on CTA after 24 hours, there were MORI score of 0 or 1 The MORI score had assessed revascularization based on the results of the CTA

- Recanalization was evaluated according to the modified Mori grade: Grade 0, no reperfusion; Grade 1, movement of thrombus not associated with any flow improvement; Grade 2, partial (branch) recanalization in < 50% of the branches in the occluded arterial territory; Grade 3, nearly complete recanalization with reperfusion in

≥ 50% of the branches in the occluded-arterial territory

2.3.2.2 Evaluate clinical effectiveness

Evaluate clinical efficacy at discharge, after 90 days and mortality by disability modified Rankin scale (mRS)

2.3.2.3 Evaluate the safety of treatment

- Identify side effects due to contrast: allergy, anaphylactic shock, acute kidney injury according to the most up-to-date standards

- Determine procedural complications: access-site problems(hematoma), cerebral arterial dissection, embolization to new or target vessel territory

+ Embolization to new or target vessel territory Evaluating during the thrombectomy

+ Cerebral arterial dissection: Artery tear and bleeding of the

- Determining levels intracerebral hemorrhage (ICH) include

hemorrhagic transformation, subarachnoid hemorrhage (SAH)

+ Evaluate the hemorrhagic transformation level after thrombectomy on CT scan based on ECASS II trial including 4 types: hemorrhage infarction type 1 (HI1) was small hyperdense petechiae; hemorrhage infarction type 2 (HI2) was more confluent hyperdensity throughout the infarct zone; without mass effect; parenchymal hematoma type 1 (PH1): homogeneous hyperdensity occupying <30% of the infarct zone; some mass effect; parenchymal hematoma type 2 (PH2): homogeneous hyperdensity occupying>30%

of the infarct zone; significant mass effect

+ Evaluation of subarachnoid hemorrhage based on CT scan

- Symptomatic intracranial hemorrhage (sICH) is defined as follows: + Clinical: change NIHSS score ≥ 4 within 24 hours after thrombectomy

+ Computed tomography image: There was an image hyperattenuation in the brain tissue, infarct or subarachnoid cavity With the hemorrhagic transformation were usually parenchymal hematoma type 2 (PH2) or subarachnoid hemorrhage.

- Identify complications related to treatment: hospital-acquired

2.2 Statistical Analysis

Data processing with SPSS 22.0 with algorithms: ratio comparison (χ2 or exact Fisher test); univariate analysis; multivariate logistic regression analysis Quantitative data are expressed as mean

X ± SD; p < 0.05 was considered statistically significant

CHAPTER 3 - RESULTS 3.1 General characteristics

3.1.1 Characteristics of the studies objects

- The total number of studies objects were 103

- Age and sex: the average age was 64.7 ± 12.6 years (from 32 to 84) The age group over 60 accounts of 68.9% 61.2% of men patients, 38.8% of women

- History: the most common was hypertension (57.7%), atrial fibrillation (32.5%), valvular heart disease (22.8%) and other factors such as heart failure (14.6%), pre-stroke (13.8%), diabetes (13%)

Chart 3.3 Clinical characteristics at admission

Common signs such as hemiparesis 97.1%; 7th central facial palsy

90.3%; expressive aphasia accounts for 75.7% Conjugate eye deviation accounted for 22.3%

Chart 3.6 Mean Glasgow and NIHSS change

The mean Glasgow score at admission was 11.4 and at discharge was 12.8 The mean NIHSS sacle at admission was 17.1 and at discharge was 9.3

3.2.2 Characteristics of computed tomography images

75.7%

97.1%

90.3% 34.0%

22.3%

Expressive aphasia

Hemiparesis7th Central facial palsy

Table 3.11 Characteristics of computed tomography images at

<0.01 3.5 Ischemic 73 65.9 24 55.8 49 81.7

Cerebral

atrophy 15 14.6 9 20.9 6 10.0 >0.05 0.4 Pre-stroke 20 19.4 8 18.6 12 20.0 >0.05 1.1 With AIS due to LVO of anterior system, CT images normal was 29.1% The rate of patients with ischemic after 3 hours (81.7%) was higher than before 3 hours (55.8%), the difference was statistically significant with p<0.01, odds ratio OR = 3.5

Table 3.12 Early signs of infarction on non-contrast computed

tomography Signs Total ≤ 3 hour > 3 hour

effacement 31 30.1 7 16.3 24 40.0 <0.05 3.4 Loss of gray-

lentiform nucleus 13 12.7 1 2.3 12 20.0 <0.05 10.5 Obscuration of the

Sylvian fissure 25 24.3 3 7.0 22 36.7 <0.01 7.7