Microsoft Word 3b Tóm t¯t LATS Eng MINISTRY OF EDUCATION AND TRAINING MINISTRY OF HEALTH HANOI MEDICAL UNIVERSITY ======= NGUYEN QUANG ANH EVALUATING THE CHARACTERISTIC OF DIAGNOSTIC IMAGING AND THE R[.]
Trang 1MINISTRY OF EDUCATION AND TRAINING MINISTRY OF HEALTH
HANOI MEDICAL UNIVERSITY
=======
NGUYEN QUANG ANH
EVALUATING THE CHARACTERISTIC OF
DIAGNOSTIC IMAGING AND THE RESULTS OF
MECHANICAL THROMBETOMY IN THE TREATMENT
OF ACUTE ISCHEMIC STROKE PATIENTS
Speciality : Radiology & Nuclear medicine
ABSTRACT OF DOCTORAL THESIS
HA NOI - 2023
THE THESIS HAS BEEN COMPLETED AT HANOI MEDICAL UNIVERSITY
Supervisor: Prof Pham Minh Thong
Reviewer 1:
Reviewer 2:
Reviewer 3:
The thesis will be present in front of board of university examiner and reviewer level at on
This thesis can be found at:
- National Library
- Hanoi Medical University Library
Trang 2LIST OF PUBLISHED ARTICLES CONCERNING THE THESIS
1 Nguyen Quang Anh Effect of mechanical thrombectomy with vs
without intravenous thrombolysis in acute ischemic stroke Clin
Ter 2022; 173 (3): 257 - 264
2 Nguyen Quang Anh Results of mechanical thrombectomy in
acuted ischemic stroke patients due to large vessel occlusion at
Bach Mai hospital: sharing experiences from 227 cases JMR 2022;
154 E10 (6): 28 - 36
INTRODUCTION Cerebral stroke includes hemorrhage and infarction, in which ischemic stroke accounts for 80-87% of cases The consequences of ischemic stroke, if not detected and treated in time, are severe, leaving
a double burden on both families and society Similar to the world, in Vietnam, with the shift of the disease pattern according to the development of modern society, the number of patients with acute ischemic stroke every year tends to increase rapidly while the number
of our stroke centers is not enough to meet both quantity and quality With all these reasons, a trial with large sample size in Vietnam to have the overview of imaging characteristics and to analyze the effectiveness of mechanical thrombectomy techniques are needed Therefore, we conduct a study “Evaluating the characteristic of dianostic imaging and the results of mechanical thrombectomy
in the treatment of acute ischemic patients”, with two details purposes:
1 Describe CT Scanner and MRI imaging charateristics in patients with acute ischemic stroke due to large vessel occlusion
2 Evaluating effects of mechanical thrombectomy in acute ischemic stroke patient with large vessel occlusion
1 The need of thesis implementation:
The number of patients with acute ischemic stroke increased in all hospitals at all levels Timely diagnosis and treatment help to reduce disability rates and improve the patient's chances of recovery and return
to a normal life In Vietnam, a lot of studies about this topic were reported in the past 5 years, which have been published both domestic and international journals However, there are still many controversial issues that need to be clarified with a sufficiently large sample size In the diagnosis, CT Scanner is preferred because of its suitability for the patient's urgent situation but the application of multiphase (evaluating collateral circulation) and perfusion imaging (identifying the core, penumbra volume) are still limited In treatment, there have been many trials were conducted and published after the success of 5 randomized controlled trials in 2016 that proved the effect of mechanical
Trang 3thrombectomy treatment Some issues still need to be clarified such as:
the role of rt-PA, a different effect between mechanical devices or
factors affecting the rate of recanalization and clinical recovery post
treatmentn Therefore, conducting a research at a comprehensive stroke
center with a large number of patients will help to partially solve some
of problems and improve treatment effectiveness in Vietnam
2 Novel contributions of the thesis:
- ASPECTS was 7.76 ± 1.20 (median 8) and pc-ASPECTS was
7.55 ± 1.62 (median 8) The highest rate seen in M1 occlusion with
41% of patients The average of collateral score was 3.32 ± 1.44,
which seen the most in tandem occlusion group In the perfusion map,
the average volume of infarction was 23.5 ± 9.0 cm3, which is smaller
in groups with higher ASPECTS (9-10 point) and better collateral
score (4-5 point)
- Good recanalization (TICI 2b-3) was 84.6% while the rate of
successful first-pass was 47.6% The hemorrhagic rate seen in 25.1%
of patients but only 3.1% was symptomatic intracranial hemorrhage
There was 2.7% of severe complications After 3 months, good clinical
recovery (mRS ≥ 2) was 65.2% and the mortality was 12.8%
- There was no significant difference seen both in 3 groups of
mechanincal devices (stent, aspiration, solumbra) and in 2 kinds of
treatment in the first 4.5 hours (thrombectomy alone vs thrombectomy
+ intravenonus rt-PA)
- Procedural time ≤ 60 mins (OR 5,952; 95% CI 2,755 – 12,821, p
= 0,000) was an independent predictor to the successful recanalization
(TICI 2b-3) Age < 80 (OR 3,842; 95% CI 1,764 – 8,365; p = 0,011),
NIHSS baseline < 18 (OR 4,917; 95% CI 2,524 – 9,580; p = 0,000),
good collateral (OR 15,047; 95% CI 7,181 – 31,529; p = 0,000) and
good recanalization (OR 3,006; 95% CI 1,439 – 6,276; p = 0,005)
were both independent factors in predict the good outcome (mRS 0-2)
at 90 days after treatment
3 Thesis layout:
The thesis consists of 128 pages Apart from the introduction (2 pages), the conclusion (2 pages), the recommendations (1 page) and the limitation (1 page), it also has four chapters include: Chapter 1: Overview 43 pages; Chapter 2: Materials and methods 18 pages; Chapter 3: Results 25 pages; Chapter 4: Discussion 36 pages The thesis consists of 26 tables, 26 pictures, 10 charts, and 182 references (Vietnamese: 8, English: 174)
Chapter 1 OVERVIEW 1.1 Literature review in the world
In terms of diagnosis, according to the recommendations of the American Heart Association and Stroke, computed tomography is still preferred while magnetic resonance imaging is recommended for the diagnosis of vertebro - basilar occlusion or wake-up stroke Evaluation
of collateral circulation was studied by Menon since 2014 on 140 patients and then showed that this method has good reliability in assessing collateral in ischemic areas (n = 30, k = 0.81 , p<0.01), reduce uncertainty in treatment decisions and have better predictive value of clinical recovery After the success of the DAWN and DEFUSE III trials in 2018, the therapeutic intervention window was extended up to 24 hours with strictly criteria selection based on perfusion imaging In treatment, the breakthrough improvement of thrombectomy devices has resulted in superior results in the group using the new generation stents compare to intravenous rt-PA group Meta-analysis based on data of 5 randomized trials in 2016 (MR CLEAN, EXTEND IA, ESCAPE, SWIFT PRIME, REVASCAT) including 1287 patients performed by the Hermes Collaboration showed a significant reduction in disability after 90 days in patients treated by thrombectomy compared to control group (OR 2.49, 95%
CI 1.76-3.53; p < 0.0001) Thanks to endovascular thrombectomy, the number need to treat (NNT) was only 2.6 to obtain a good recovery (mRS≥2) Efficacy relative to some sub-group including patients with age ≥ 80 years (OR 3.68, 95% CI 1.95-6.92), time from onset to administration ≥ 300 minutes (1.76, 1.05-2.97) and non indication for
Trang 4IV rt-PA (2.43, 1.30-4.55) Mortality rate after 3 month and
symptomatic hemorrhagic transformation were not significant
difference when comparing between all groups This analysis once
again confirms the benefit of mechanical intervention with
new-generation stents in patients with acute cerebral ischemia due to
anterior circulation occlusion Meanwhile, the introduction of large
bore catheter (with inner diameter from 0.060" - 0.072") has brought
another effective choice in thrombectomy treatment In 2015, the study
by Almandoz et al showed a better clinical recovery rate at 90 days
using the ADAPT technique (55.6%) compared with the solumbra
group (30.9%) The results also suggest that the ADAPT technique is
considered an independent predictor of good clinical outcome in
patients with anterior circulatory occlusion However, in 2017, the
ASTER randomized clinical trial of 381 patients comparing direct
aspiration (192 patients) with stents retriever (189 patients) for major
artery occlusion did not show a significant difference in clinical
recovery (45% vs 50%), where the rate of complete recovery (mRS 0)
was lower in the thrombectomy group (24% vs 40%) The “rescue
treatment” applied 33% in the aspiration group and 24% in the stent
group both increased the good recanalization rate (TICI 2b-3) from
63% and 68% to 85.4% and 83.1%, respectively (p = 0.53)
Additionally, rt-PA treatment was previously using in “rescue”, where
patients were infused intravenously and wait 60 minutes for clinical
improved observe If there is no clinical change and NIHSS score ≥ 8
were considered as a treatment failure, then endovascular intervention
is implemented These limitations were also shown in the design of 2
studies IMS III and Synthesis By the end of 2016, this method had
changed from “rescue” to “combined” meaning indicated patients will
receive rt-PA right on the computerized tomography table, then
immediately transferred to the intervention room to conduct
mechanical thrombectomy This takes advantage of both methods and
saves time for the recanalization This change is also reflected in the
treatment recommendations from 2018 of the American Heart
Association or European Stroke Association in patients with major
embolism within the first 4.5 hours
1.2 Literature review in Vietnam Procedural thrombectomy in Vietnam have been conducted since 15 years ago in which the second generation device (stent Solitaire) was first used at Bach Mai Hospital in 2012 However, the intervention procedure was still no consensus because of the limited results of studies at this time Thanks to the success of 5 major international studies in 2016 and the change in recommendations of the American Heart Association and Stroke during 2015 - 2018, many studies in Vietnam in the past 5 years were conducted with a good design showing many encouraging results in which 3 major intervention centers at Bach Mai Hospital, People's Hospital 115 and Military Hospital 103 took part in DIRECT-SAFE study Nguyen Hoang Ngoc et al evaluated 138 patients with acute ischemic stroke due to large vessel occlusion at Military Central Hospital 108 from July 2016 to June 2017 The results showed that 45.7% occlusion of the middle cerebral artery, 36.2% of the internal carotid artery and 17.4% of the basilar artery, ASPECTS > 6 was 95% The good recanalization rate (TICI 2b-3) was 79.7% and the good outcome (mRS 0-2) was 58.7% Another research by Vu Viet Lanh et
al (2019) evaluated 104 patients with large vessel occlusion treated by Solitaire stents at People's Hospital 115 As a result, there were 55.8% occlusion of middle cerebral artery, 37.5% occlusion of internal carotid artery and 6.7% occlusion of basilar artery The rate of good recanalization seen in 73.9% of patientns while 12.5% of symptomatic intracranial hemorrhage discovered Follow-up after 3 months, good clinical recovery rate (mRS 0-2) reached 50% and mortality was 23.1% The study also showed factors related to good neurological recovery including: age < 70, good revascularization, good collateral circulation, asymptomatic hemorhage and NIHSS baseline ≤ 15 (p < 0.05) At Bach Mai Hospital, Dao Viet Phuong et al (2019) conducted a study on 86 patients with the anterior circulation occlusion within the first 6 hours which was treated by using a combined therapy (intravenous rt-PA + thrombectomy) The results showed that the good recanalization (TICI 2b-3) achieved in 91% of patients, of which the complete recanalization rate (TICI 3) was 52% Symptomatic hemorrhagic transformation only accounted for 5.8% The rate of good clinincal recovery (mRS 0-2) was 69.8% and the rate of complete recovery (mRS 0-1) was 53.5% Most recently, a trial by Tran Anh Tuan et al (2020) on 22 patients with basilar artery occlusion showed that the rate
Trang 5of good recanalization and clinical recovery was 68.2% and 50%,
respectively The rate of major bleeding was 13.6% and the mortality rate
was 36.4% According to the authors, low parenchymal injury
(pc-ASPECTS ≥ 7) and good revascularization rate (TICI 2b-3) were
predictors of good clinical outcome (mRS 0-2) Another study by Vu
Dang Luu et al (2020) including 17 complicated cases of tandem
occlusion recorded a good recanalization rate (TICI 2b-3) reached 82.4%
There were 10/17 patients undergoing acute stenting, but there was no
difference in treatment outcomes between the two groups (retrograde vs
antegrade thrombectomy, p > 0, 05) The rate of symptomatic
hemorrhagic transformation post treatment was 11.8% and good outcome
(mRS 0-2) after 3 months was 47.1%
Chapter 2 MATERIALS AND METHODS 2.1.Research subjects
2.1.1 Inclusion criteria
Based on AHA/ASA 2018 guidelines and recommendation:
- Age ≥ 18; NIHSS ≥ 6
- ASPECTS ≥ 6 with anterior occlusion; for posterior occlusion:
pc-ASPECTS ≥ 7 or no pons lesion idenntified
- Eveidence of large vessel occlusion (ICA, M1, M2, basilar
artery) showed in diagnostic imaging
- Time from onset to administration not more than 16 hours For
late window 6 – 16 hours: criteria based on DEFUSE 3 (core
volume ≤ 70ml and ratio of penumbra/ core ≥ 1,8)
- Patient’s familly understand about the procedure and agree to
sign in a commitment to treatment
2.1.2 Exclusion criteria
- Wake-up stroke
- Any hemorrhage shown in image
- Chornic occlusion (Moya Moya disease…)
- Pre - mRS ≥ 2 (before stroke)
- Severe condition with other diseases (kidney failure, invasive
cancer…) and could not be followed up
2.2 Methodology 2.2.1 Methodology Prospective clinical intervention study, pre and post treatment evaluation, non-randomized, non-blind and no control group
2.2.2 Number of patient Estimated 227 patients 2.2.3 Data analysis The data were analyzed using SPSS 22.0 software Algorithms used in the study include::
- General descriptive statistics of research variables
- Qualitative variables are described by frequency and percentage, using the X2 test (if the standard variable) or the "Fisher exact test" (when the non-standard variable with any expected frequency has a value < 5)
- Quantitative variables are described by mean and standard deviation (if standard variable) or median value (if non-standard variable) When comparing 2 means: use T-test with standard variables and Mann-Whitney test with non-standard variables For multiple means, use the ANOVA test with the standard variable and the Kruskal–Wallis test with the non-standard variable
- Perform binary comparison to identify significant clinical, imaging, and interventional factors affecting the good revascularization rate (TICI 2b-3) and good clinical recovery (mRS 0-2) after 3 months
- Perform multivariable regression analysis to variables with independent prognosis to predict the good recanalization (TICI 2b-3) and good clinical recovery (mRS 0-2) after 3 months follow-up
- p was considered as a significant difference when its value ≤ 0,05
Trang 6Chapter 3 RESULTS The study was conducted on 227 patients (N) with acute ischemic
stroke who underwent mechanical thrombectomy at the Radiology
Center of Bach Mai Hospital: 205 cases (N1) with anterior occlusion
and 22 cases (N2) ) with basilar occlusion There were 178 patients
(N3) who came to the hospital in the first 4.5 hours and 32 cases came
within the 6-16 hour window (that was controlled by perfusion
nimaging)
3.1 General characteristics of the patients
3.1.1 Age and gender
- Mean was 65±13 (22-90) The age group < 45 years accounted
for 5.7%, the middle-aged group (45-69) accounted for 55.5% and the
elderly group (>70) accounted for 38.8% Male/female ratio = 1.2%
3.1.2 Clinical and time characteristic at hospital admission
- The rate of hypertension was 59.5%, hyperglycemia was 58.6%
and atrial fibrillation was 24.7% NIHSS score at admission was
14.27 ± 4.8
- The mean time from onset to hospital admission was 203 ± 153
minutes; from hospital admission to first image was 39 ± 37 minutes;
from hospital admission to femoral puncture was 98 ± 55 minutes
3.2 Imaging characteristic of large vessel occlusion
3.2.1 Occlusion site
- The rate of M1 middle cerebral artery occlusion was 41.9% (95
patients), internal carotid occlusion was 23.8%, M2 segment occlusion
was 13.2% and tandem occlusion was 11.5% There were 9.7% cases
(22 patients) of basilar artery occlusion
3.2.2 Non contrast imaging charateristic
- The mean ASPECTS and pc-ASPECTS was 7.76 ± 1.20 and 7.55
± 1.62, respectively The time from onset to the first scan of anterior
and posterior occlusion was 241 ± 148 minutes and 243 ± 181
minutes, respectively
- For anterior occlusion, there was a significant difference in
ASPECTS at different sites (p=0.01): M2 occlusioin had the least
parenchymal damage with an average ASPECTS score of 8 33 ± 1.09
and the time from onset to the first imaging was shortest: 148 ± 130 minutes (p= 0.05) Occlusion of the internal carotid artery and the M1 had more parenchymal damage, respectively the average ASPECTS
of 7.69 ± 1.23 and 7.54 ± 1.13 Time from onset to hospital imaging
of the tandem group was the longest: 279 ± 227 minutes, p = 0.02
- The group of patients with more severe clinical condition (higher NIHSS) had more parenchymal damage (ASPECTS 6-7) and vice versa, but the difference was not statistically significant (p = 0.09) 3.2.3 Collateral characteristic in CT Scanner multiphase
- The mean collateral score was 3.32 ± 1.44 (for anterior occlusion) Tandem group had the best collateral score (3.5 ± 1.3) but the difference was not statistically significant when compared with others (p = 0.95)
- The group of patients with good clinical status (lower NIHSS) has a better collateral score (13.1 ± 4.3) and vice versa There was a statistically significant difference between the study groups (p=0.04) 3.2.4 Perfusion imaging characteristic
- 32 patients admitted to the hospital with time window > 6 hours underwent cerebral perfusion imaging The mean time was 505 ± 134 (min) and the mean core volume was 23.50 ± 9.00 (cm3)
- Less parenchymal lesions (ASPECTS 8-10) have a smaller core volume (20.85 ± 9.35) compared with more parenchymal lesions (ASPECTS 6-7) corresponding to a larger core volume (26.58 ± 7.81) but the difference was not significant (p = 0.07) Time from onset to hospital admission between groups was not significant also (p
= 0.61)
- Core volume decreased gradually from the group with poor collateral circulation (29.00 ± 5.52) to moderate (23.74 ± 7.76) and good (21.81 ± 10.15) while penumbra volume gradually increased, 2.50 ± 0.75 (poor); 3.57 ± 1.86 (moderate) and 5.11 ± 3.42 (good), respectively The difference was not statistically significant (p = 0.30 and 0.14) The time from onset to hospital admission was different between groups, but not statistically significant (p = 0.27)
Trang 73.3 Endovascular mechanical thrombectomy effect
3.3.1 Characteristic and general results
- Of the 227 patients undergoing mechanical thrombectomy,
80.6% received endotracheal anesthesia and 19.4% received local
anesthesia The average intervention time was 40 ± 27 minutes (9 –
150) with an average number of pass was 2.73 ± 1.58 There were 178
patients admitted to the hospital in the first 4.5 hours of which 64
cases (accounting for 28.2%) were treated with rt-PA
- The good recanalization (TICI 2b-3) was 84.6% There were 6
patients with severe complications related to the procedure: 4 cases of
dissection (1.8% - of which 1 case died, accounting for 0.4%) and 2
cases of perforation (0.9% - leading to both mortalities) The mean
number of thrombectomy pass was 1.87 times (median 1, range 1-10)
- 24 hours follow-up, the mean NIHSS was 10.68 ± 7.76, lower
than that at admission with an average reduction of 3.59 ± 4.0 points
130 patients decreased ≥ 4 points and 61 patients decreased ≥ 8 points
with 86.9% of them having good clinical recovery after 3 months
- 148 patients had a good clinical recovery (mRS 0-2), reaching
the rate of 65.2% while 29 cases of death (mRS 6) accounted for
12.8% 7 patients had symptomatic transformation, accounting for
3.1% Asymptomatic hemorrhage seen in 50 patients, accounting for
22%
- Good clinical recovery after 3 months (mRS 0-2) seen in
occlusion group of internal carotid artery, M2, tandem and M1 were:
59.3%, 63.3%, 69.2% and 73.7%, respectively Occlusion of the
middle cerebral artery (M1 and M2 segments) had a lower mortality
rate, 6.3% and 6.7%, respectively With posterior circulation, the
good clinical recovery rate was only 40.9% while the mortality was
highest (45.5%)
Figure 3.1 Rate of good recanalization and clinical recovery by number of
thrombectomy pass
- 47.6% had good revascularization (TICI 2b-3) and 35.2% had good clinical recovery (mRS 0-2) with only 1 pass The cumulative rate of good recanalization increased to 66.1% and 77.1% after the 2nd
and 3rd pass After the 4th, the increase was not significant (<1%) The rate of good clinical recovery at the cumulative 90 days also increased
to 51.1% and 59.5% after 2nd and 3rd pass After the 4th, the increase was not significant (<1%)
3.3.2 Comparison in groups of treatment 3.3.2.1 Based on mechanical device
- Characteristics at hospital admission between 3 groups of devices (stent, aspiration and solumbra) did not show statistically significant differences (p > 0.05) in terms of clinical factors (age, gendner, NIHSS), imaging (ASPECTS and pc-ASPECTS) and time from onset
to hospital admission The time from hospital admission to femoral puncture in the solumbra group (stent + aspiration) was 85 ± 38 minutes, shorter than the stent group (107 ± 58 minutes) and the aspiration group (96 ± 58 minutes) The difference was statistically significant (p=0.04)
Trang 8Table 3.1 Results comparison between 3 groups of mechanical devicie
- Between the 3 groups of device, the occlusion rate at M1, basilar
artery and tandem was similar but the stent group had a lower rate in
the internal carotid artery (12.9%) and higher in the M2 (22.6%), the
difference was significant (p < 0.05) The rate of using combined
intravenous rt-PA before thrombetomy in all 3 groups did not differ:
26.7% - 30.1% with p = 0.83
- The mean intervention time in aspiration group was shortest: 35 ±
23 minutes, the difference was not statistically significant (p = 0.21)
The average number of pass in the stent group was least (1.61) with
significant difference (p = 0.02) The stent group had a significantly
lower rate of rescue therapy (using a second device) than the
aspiratiion group: 7.52% versus 33.33%, p < 0.05 The rate of good
recanalization (TICI 2b-3) achieved at first pass was highest in the
stent group: 61.3%, p = 0.04 but the general recanalization was all
good post procedure in all 3 groups without statistical difference (p =
0.55)
- The rate of symptomatic intracranical hemorrhage post treatment was not recorded in the stent group, while the other 2 groups had no difference (5.6% and 4.5%, p > 0.05) Good clinical recovery and mortality after 3 months in 3 intervention groups did not show a statistically significant difference (p = 0.32)
3.3.2.2 Based on treatment in the first 4.5 hours
- Characteristics at hospital admission between the 2 treatment groups did not differ (p > 0.05) in terms of imaging and most of the clinical features The time from onset to hospital admission in the combined group (IV rt-PA + thrombectomy) was significantly shorter (p < 0.05), but the time variables from hospital admission to femoral artery puncture did not differ between the 2 groups (p > 0.05)
Table 3.2 Results comparison between 2 groups of treatment
in the first 4.5 hours
- In the group of thrombectomy alone, the occlusion rate in the internal carotid artery was higher (28.1%) while in the M2 and tandem group, this rate was lower (12.3% and 7.9%) compared with combined group, the difference was statistically significant (p < 0.05)
Trang 9Other parameters related to the procedure including time of
intervention, number of pass, good recanalization and hemorrhagic
transformation rate, there was no difference (p > 0.05) The good
clinical outcome after 3 months in the 2 groups of treatment did not
show a statistically significant difference (p = 0.60)
3.3.3 Independent factors affecting the good recanalization and
good clinical recovery rate after 3 months
- Factors affecting the good recanalization were: no extracranial
stenosis (p = 0.022) and intervention time ≤ 60 minutes (p = 0.000)
In multivariate regression analysis, intervention time ≤ 60 min was
the most independent factor affecting the good revascularization rate
post treatment (OR 5,952; 95% CI 2.755 – 12,821, p = 0.000)
- Factors correspondinig to the rate of neurological recovery after
3 months were: age < 80, hypertension, atrial fibrillation, NIHSS
admission < 18 points, degree of collateral circulation, degree of
revascularization and symptomatic transformation post thrombectomy
(p < 0.05) In multivariable regressionn analysis, age <80 (OR 3.842;
95% CI 1.764 – 8.365; p = 0.011), NIHSS admission < 18 points (OR
4.917; 95% CI 2.524 – 9,580; p = 0.00), good collateral score (OR
15,047; 95% CI 7.181 – 31,529; p = 0.000) and good
revascularization (OR 3.006; 95% CI 1.439 – 6,276; p = 0.005) were
the independent factors, having the most influence on good clinical
outcome (mRS 0-2) at 90 days after treatment
Chapter 4 DISCUSION 4.1 General characteristics of the patients
4.1.1 Age and gender
The mean age in our study was 65 ± 13, in which the youngest
patient was 22 and the oldest was 90 This result was higher than some
domestic results of Nguyen Huy Thang (60.5 ± 12.2) and Dao Viet
Phuong (61.9 ± 11.8) Compared with some international studies,
patients in our study had the same mean age with MR CLEAN and
SWIFT PRIME but lower than ESCAPE The increase in age
adversely affects clinical recovery as in the study of Weinar et al In
our study, the elderly group (> 70 years old) accounted for 38.8%, of
which the group > 80 years old accounted for 14.1% (32 patients) According to the current data, older age is not a contraindication to mechanical thrombectomy It should be noted that the rate of stroke in young people tends to increase, especially in the 40-45 year old group Our study recorded that young patients with cerebral ischemic stroke accounted for 5.7%, similar to the statistics in the world (from < 5% to 20%) Additionally, the research results showed that men predominate
in terms of gender with 55%, 1.2 times higher than women, lower than
Vu Viet Lanh study (60.4% male, male/female ratio was 1.5)
4.1.2 Clinical and time characteristic at hospital admission Our study recorded the mean value of NIHSS at the time of admission was 14.27 ± 4.8 (range 8-20), which were both lower than other international studies In an analysis of 1281 patients, Adam et al showed that NIHSS was valuable in predicting clinical outcomes after treatment, with a score of < 6 having a good prognosis while a score of
> 16 was often related with high mortality and disability rates In our study, the proportion of patients with hypertension and hyperglycemia predominated, 59.5% and 58.6%, respectively The rate of hypertensive patients was similar to the study by Toyoda (61%) and significantly higher than the study of Mai Duy Ton and Dao Viet Phuong (27.9%) In this study, we discovered atrial fibrillation by electrocardiogram in 56 patients, accounting for 24.7% This result is lower than that of Vu Viet Lanh (26%) and MR CLEAN (28.3%) In our study, the median value of time from onset to hospital admission
as 165 minutes Compared with international studies, this was still a long time (1.5-2 times) and would reduce the patient's chance of getting treatment It was noteworthy that the time from imaging to femoral puncture was shortened with a median value of 51 minutes, equivalent to the value in the ESCAPE study and shorter when compared with EXTEND-IA and SWIFT PRIME trials
4.2 Imaging characteristic of large vessel occlusion 4.2.1 Occlusion site
The results in our study showed that the distribution of occlusion site was consistent with the general trend of large studies in the world when the anterior circulation accounts for the majority (90.3%) with
Trang 1095 cases of M1 occlusioin (41.9%) while the vertebro-basilar
occlusion only account for 9.7%
4.2.2 Non contrast imaging charateristic
We found that the group of patients with large vessel occlusion
(internal carotid artery, M1 and basilar artery) had a higher degree of
parenchymal damage, corresponding to an average ASPECTS/
pc-ASPECTS of 7.69 ± 1.23 , 7.54 ± 1.16 and 7.55 ± 1.62 The M1 group
had lower ASPECTS values compared to other sites of the anterior
circulation The reason was that the patients in this group had a late
admission time (215 ± 136 minutes), so there was more parenchymal
damage, the difference was statistically significant (p < 0.05) A
special feature was that the tandem group had the time from onset to
hospital admission and from onset to imaging was longest (242 ± 221
minutes and 279 ± 227 minutes, respectively), however, the
parenchymal lesions according to ASPECTS were not much (only
inferior to M2 occlusion group) This was consistent with the
progression of chronic vascular stenosis that helped to created good
collateral anastomosis Our study did not have a low ASPECTS
subgroup (< 6), but the analysis results also showed a concordance
between imaging and clinical in patients with ASPECTS 6-7
(moderate parenchymal lesions) had worse clinical status in cobination
with higher NIHSS (14.3 ± 4.6) at the time of admission This was
similarly to the study of Mai Duy Ton and Dao Viet Phuong
4.2.3 Collateral characteristic in CT Scanner multiphase
When assessing collateral circulation in patients with anterior
occlusion (205 cases) by CT Scanner multiphase, we recorded an
average collateral score of 3.32 ± 1.44, in which 119 cases with good
circulation (58%), 60 cases with moderate (29.3%) and 26 cases with
poor collaterals (12.7%) The M1 occlusion group had the lowest
collateral score (3.27 ± 1.41) while the tandem group had the highest
collateral score (3.5 ± 1.3), which was suitable thanks to the presence
of surface collateral The study results also showed that, in the group
of patients with good collateral circulation, the mean NIHSS at
baseline was lower (13.1 ± 4.3) compared with the other two groups
(> 14.5), a statistical significant difference This was similar to the
conclusion of Hwang when evaluating 86 patients with middle cerebral artery occlusion, noting that the group with poor collateral circulation had a severe clinical condition and a higher risk of atrial fibrillation compared with the another group without these factors 4.2.4 Perfusion imaging characteristic
There were 32 cases admitted to hospital beyond 6th hour needed
to undergo computed tomography perfusion The results showed that although the mean time to hospital admission of this group was 505 ±
134 minutes (equivalent to 6.5 hours), the average ischemic core volume recorded was only 23.5 ± 9.0ml The ratio of the volume between the penumbra and the core was 4.23, consistent with the selection criteria of DEFUSE 3 When comparing in the subgroups based on ASPECTS and collateral score, the results showed that good ASPECTS (8-10) and good collateral score (4-5 points) corresponding to the lower core volume on cerebral perfusion map (20.85 ± 9.35 vs 26.8 ± 21.08 or 21.81 ± 10.15 vs 23.74 ± 7.76 and 29.0 ± 5, respectively) EXTEND-IA was one of the pioneering studies using quantitative assessment based on infarction volume (measured on perfusion map) <70ml as a criteria for patient selection without applying ASPECTS like most other studies
4.3 Endovascular mechanical thrombectomy effect 4.3.1 Characteristic and general results
In our study, the rate of endotracheal anesthesia was 80.6% while local anesthesia accounted only for 19.4% A meta-study by Feil et al
on 6635 stroke patients who underwent mechanical thrombectomy in Germany from 2015 to 2019 showed that the rate of endotracheal anesthesia accounted for the majority (67.1%) but resulted in slowing down time to femoral puncture compared to sedation alone (71 versus
61 minutes, p < 0.001) In multivariable regression analysis, the endotracheal anesthesia was also a predict factor in reducing the good recovery post thrombectomy (OR = 0.82, CI 0.71 - 0.94, p = 0.004) The average number of thrombectomy pass in our study was 1.87 (median 1) with 47.6% having good revascularization at first-pass The results in Figure 3.1 showed that within 4 passes (219 patients), the cumulative revascularization rate increased rapidly, from 47.6% to