Stent retrieval thrombectomy has recently been the standard treatment for acute ischemic stroke with large artery occlusion. However, the development of catheters for suction thrombectomy has recently led to results comparable to that of stent retrieval thrombectomy (SRT). This study aimed to analyze the safety and efficacy of forced suction thrombectomy (FST) using the SOFIA Plus (MicroVention Terumo, Tustin, CA, USA) device.
We included patients with acute ischemic stroke who underwent FST using the SOFIA Plus device at our institution. Medical records and angiographic data were reviewed, and the results of this study were compared with those of other FST studies.
A total of 35 patients were included in this study. The occlusion sites were the internal carotid artery terminal (4), M1 segment (20), and posterior circulation (11). Of the 35 patients, FST was performed in only 21 (60%) patients, and the remaining 14 (40%) patients underwent SRT and FST. In all cases, the recanalization rate was 100%, and the average time from groin puncture to recanalization was 21±4.94 min. In particular, the average time required to reach the SOFIA Plus lesions from the groin puncture was 10.44±5.06 min and about 67% of the FST patients were recanalized at the first attempt. Three-months modified Rankin Scale (mRS) score of ≤2 was observed in 52% of the patients.
Forced suction thrombectomy using the SOFIA Plus yielded a high recanalization rate within a shorter time. In particular, the recanalization rate was higher than that reported in previous studies using other types of suction devices.
Several prospective randomized clinical trials in 2015 demonstrated the effectiveness of mechanical thrombectomy in the treatment of acute ischemic stroke caused by large artery occlusion [
However, good results have recently been reported for suction thrombectomy using a large-bore catheter. Suction thrombectomy has several names, but the methods are similar [
This study was approved by the institutional review board. The requirement for written informed consent to participate in the study was waived. All methods were performed in accordance with the relevant guidelines and regulations by including a statement. The medical records of all patients with acute ischemic stroke who underwent mechanical thrombectomy at our institution from November 2017 to July 2019 were reviewed.
The FST was performed in patients with acute ischemic stroke due to large-artery occlusion. Patients who underwent thrombectomy were initially diagnosed radiologically with a diffusion-perfusion mismatch on radiological examination. Patients with acute ischemic stroke of the anterior circulation within 6 h of symptom onset and within 24 h of symptom onset in acute ischemic stroke of the posterior circulation were included. Within 4.5 h of symptoms onset, intravenous tissue plasminogen was used.
Patients in whom a 6 Fr SOFIA Plus was used as the forced suction thrombectomy device were enrolled, and those in whom another catheter or stent retrieval thrombectomy was used as the primary treatment were excluded. Patients who underwent intracranial or carotid artery stenting were also excluded.
All procedures were performed under local anesthesia by a neurointerventionist. A double coaxial system, combining a 6 Fr shuttle (Cook Medical, Bloomington, IN, USA) and a 125 cm diagnostic angiocatheter (Cook Medical, Bloomington, IN, USA) was placed in the proximal portion of the parent artery. An initial angiogram was used to determine the occlusion site and collateral vessels. The SOFIA Plus was placed proximal to the occluded site through a double coaxial microcatheter (Excelsior XT-27, Stryker, Fremont, California, USA), with the microcatheter placed in the distal branch through the occluded site to accelerate the passage of SOFIA Plus. The SOFIA Plus was pushed towards the occlusion to ensure more blood clots into the catheter, and a negative force was applied by connecting a 50 mL syringe. If it was confirmed that there was no backflow of blood through the syringe, the catheter was maintained for 3 min to inactivate the thrombus. After the 3 min, the shuttle was stopped, heparinized saline flushing was performed, and the SOFIA Plus was slowly removed while checking backflow of blood. When blood backflow was observed during the catheter removal, approximately 20 mL of blood was removed from the SOFIA Plus at that location. The roadmap image was used to assess recanalization; if recanalization was not observed, the procedure was repeated. When the SOFIA Plus was completely removed without blood backflow, the presence of a thrombus was confirmed in the tip or inner lumen of the SOFIA Plus. Stent retrieval thrombectomy was subsequently performed if recanalization was not achieved after multiple attempts or distal embolic occlusion occurred. The removal of the distal M2 embolism was attempted using SOFIA Plus.
The recanalization rate was determined by two neurointerventionists using digital subtraction angiography after thrombectomy and thrombolysis in cerebral ischemia (TICI) scale was used [
A total of 81 patients underwent thrombectomy, and the SOFIA Plus was used in 35 patients. There were 21 FST patients and 14 combined with SRT. The mean age was 68.6±14.2 years and the sex ratio included more males (22/35). There were 24 clots in the anterior circulation (ICA terminal 4, M1 segment 20) and 11 in the posterior circulation. The time from symptom onset to admission was 283 min, and from diagnosis of infarction to arterial puncture was 97 min. Intravenous tissue-plasminogen activator was used in nine patients. The patients’ demographic characteristics details are summarized in
The average time from groin puncture to catheter to lesion was 10.44±5.06 min. The recanalization time from groin puncture was 17.31±7.44 min in FST alone, 32.83±21.21 min in combined SRT, and 21.04±14.53 min in total. The average time required to reach the SOFIA Plus lesions from the groin puncture was 10.44±5.06 min. The average number of attempts in the FST alone was 1.7±1.39 times. In the combined SRT, they switched to SRT after 5.4±2.48 FST attempts. In particular, FST alone was recanalized on the first attempt in 14 patients. The total recanalization rates of TICI ≥2b and TICI ≥3 were 100% and 77.15%, respectively. The recanalization rate with TICI 3 was 80.95% for FST alone and 71.42% for combined SRT.
Distal embolic occlusion occurred in five patients. Four patients were recanalized using the SOFIA Plus, and one patient was recanalized using the combined SRT. Procedural-related hemorrhage occurred in four subarachnoid hemorrhages post-thrombectomy brain tomography, but the amount was small and there was no clinical morbidity.
The initial National Institutes of Health Stroke Scale score was 12.06±4.45 and it decreased to 7.57±5.48 at discharge. On average, the initial mRS score was 3.84±1.08, and 2.48±2.04 at 90 days after admission. Nineteen (54.28%) patients had an mRS score of ≤2 at 90 days after their admission. Two patients died 90 days after admission, and the cause of death was not directly related to stroke.
The results of forced suction thrombectomy with the Sofia Plus are summarized in
The treatment of acute ischemic stroke due to large artery occlusion has been mainly conservative for a long time, but recent prospective randomized clinical trials reported in 2015 demonstrated superior clinical effects of thrombectomy over conventional medical treatment [
Advantages of suction thrombectomy over SRT include removal without thrombus fragmentation, faster combination with SRT, and less intimal injury [
The first requirement for a successful suction thrombectomy is a large-bore catheter [
Forced suction thrombectomy using a large-bore catheter has shown faster recanalization and better clinical results than a small internal catheter [
In Jeon’s meta-analysis, if FST was selected first, the probability of using an additional device was higher than that of SRT. The combination of FST and SRT showed a high recanalization rate, but their outcome varied [
The limitation of this study was that it did not provide an objective indicator of trackability, and there was a tendency for data due to the majority of M1 occlusions. We also needed to statistically compare the results with those of other devices.
Since the outcome of patients with large artery occlusion stroke is the time of rapid recanalization from symptom onset, rapid systematic brain imaging studies and rapid recanalization are required for patients with indications. An appropriate thrombectomy device should be selected for rapid recanalization. Thus, the SOFIA Plus is considered a suitable FST device for patients with large-artery occlusion stroke.
The authors report no conflicts of interest concerning the materials or methods used in this study or the findings specified in this paper. The requirement for informed consent was waived by the institutional review board.
(A) Fluoroscopic image of SOFIA Plus placed at the occluded lesion via tortuous proximal vessel. (B) Fluoroscopic image of SOFIA Plus placed to M3 for distal embolic occlusion at M3.
Baseline patient demographics and risk factors
Patient demographics | Number |
---|---|
Age (years) | 68.6±14.2 |
Patients (male/female) | 35 (22/13) |
Clinical presentation and outcome | |
Initial NIHSS score (mean value±SD) | 12.06±4.45 |
Discharge NIHSS score (mean value±SD) | 7.57±5.48 |
mRS score of patients at 90 days (mean value±SD) | 2.51±1.75 |
Time for symptom onset to admission (minute) | 283 |
Time for diagnosis of infarction to angiogram (minute) | 97 |
Risk factors | |
Hypertension | 19 |
Diabetes | 9 |
Atrial fibrillation | 9 |
Previous antiplatelet/anticoagulant use | 6 (3/3) |
Clot location | |
Anterior circulation | 24 |
ICA | 4 |
M1 | 20 |
Posterior circulation (BA) | 11 |
IV tPA | 9 |
NIHSS, National Institutes of Health Stroke Scale; SD, standard deviation; mRS, modified Rankin Scale; ICA, internal carotid artery; IV t-PA, intravenous tissue plasminogen activator
Summary of results for forced suction thrombectomy with the Sofia Plus
SOFIA Plus (n=35) |
||||
---|---|---|---|---|
FST alone (n=21) | SRT combined (n=14) | All (FST+SRT) (n=35) | ||
Time from groin puncture to recanalization (mean minute±SD) | 17.31±7.44 | 32.83±21.21 | 21.04±14.53 | |
Time from groin puncture to catheter gets to lesion (mean minute±SD) | 10.27±5.09 | 10.85±4.96 | 10.44±5.06 | |
Average number of suction thrombectomy attempts (mean minute±SD) | 1.7±1.39 | 5.4±2.48 | 2.13±1.96 | |
TICI scale (%) | 2b | 19.04 (n=4) | 28.57 (n=4) | 22.86 (n=8) |
3 | 80.95 (n=17) | 71.43 (n=10) | 77.14 (n=17) | |
≥2b | 100 (n=21) | 100 (n=14) | 100 | |
Distal embolic occlusion (%) | 19.04 (n=4) | 7.1% (n=1) | 14.28 (n=5) | |
90-day mRS ≤2 (%) | 76.19 (n=16) | 21.43 (n=3) | 54.29 (n=19) | |
Procedural related hemorrhage (%) | 4.7% (n=1) | 21.43 (n=3) | 11.43 (n=4) | |
Fist pass effect (%) | 66.7 (14/21) | 45.7 (16/35) |
FST, forced suction thrombectomy; SRT, stent retrieval thrombectomy; TICI, thrombolysis in cerebral infarction; mRS, modified Rankin Scale; SD, standard deviation
Comparison of the present study with reported other suction thrombectomy results
Case number | Occlusion site | TICI ≥2b (%) |
Time from groin puncture to recanalization (minute) (FST alone vs combined SRT) | Recanalization on first attempt (%) | Complication (%) | mRS ≤2 (%) after 90 days | Device | ||
---|---|---|---|---|---|---|---|---|---|
FST | Combined SRT | ||||||||
Kang DH et al. [ |
22 | ICA 4 | 81.8 (Additional device: balloon 4.5, stent insertion 13.6) | 68 | No data | 31.8 (Hemorrhage) | 45.5 | Penumbra (3, 4Max) | |
MCA 14 | |||||||||
VBA 4 | |||||||||
John S et al. [ |
15 | ICA 8 | 20 | 73 | 46±30 | No data | 0 | 33 | Penumbra (ACE) |
MCA 5 | 33 (TICI 3) | ||||||||
VBA 2 | |||||||||
Turk AS et al. [ |
100 | ICA 23 | Overall 95 | 36.6±26.4 (31.6±23.3 vs 56.8±29.1) | 10 | 10 (Embolism) | 39 (missing case 23%) | Penumbra (ACE, 3~5Max) | |
Tandem 11 | 5Max alone - 75 | ||||||||
MCA 61 | 5Max ACE alone - 82 | 2 (Dissection) | |||||||
VBA 5 | |||||||||
Jankowitz B et al. [ |
112 | ICA 21 | 86.6 (Additional device: SRT 28.5%, Merci 5.3%, IA tPA 2.6%) | 70 | No data | 17 | 46.1 | Penumbra (4 Max) | |
MCA 79 | |||||||||
VBA 12 | 044 DAC, Navien | ||||||||
Tandem 21 | |||||||||
Suzuki K et al. [ |
24 | ICA 12 | 92 | 52 | No data | 7 | 79 | Penumbra (5Max) | |
M1 12 | |||||||||
Kim YS et al. [ |
70 | M1 70 | 82.9 (TICI 3 28.6) | 91.4 | 44 | 56 | 18.3 (Hemorrhage) | 60 | Penumbra (4Max) |
Stampfl S et al. [ |
115 | ICA 28 | 86.9 | 73.1±59.9 | No data | 6.1 (Hemorrhage) | No data | 5 Fr SOFIA | |
MCA 67 | |||||||||
ACA 2 | 5.2 (Embolism) | ||||||||
VBA 18 | |||||||||
Romano DG et al. [ |
152 | ICA 40 | 83.3 | 53.57 | 57.8 (44.67 vs 80.41) | No data | 7.8 (Hemorrhage) | 50.6 | 5Max ACE, 5Max Navien 0.58 5 Fr SOFIA |
MCA 73 | |||||||||
VBA 14 | 1.9 (Embolism) | ||||||||
Tandem 25 | |||||||||
Jang HG et al. [ |
29 | ICA 29 | 83 | 20 | No data | 4 (Hemorrhage) | 48 | Penumbra ACE | |
Present study | 35 | ICA 4 | 100 | 100 | 21.04±14.53 (17.31±7.44 vs 32.83±21.21) | 66.6 | 11.4 (Embolism) | 54.28 | SOFIA Plus |
MCA 20 | 81.95 (TICI 3) | 71.43 (TICI 3) | 2.8 (Hemorrhage) | ||||||
VBA 11 |
TICI scale: Thrombolysis in cerebral infarction scale, FST: Forced suction thrombectomy, SRT: Stent retrieval thrombectomy, ICA: Internal carotid artery, MCA: Middle cerebral artery, VBA : Vertebrobasilar artery