Abstract
ABSTRACT
Background
Intracranial atherosclerotic stenosis (ICAS) is a leading cause of failed mechanical thrombectomy (MT). To achieve successful recanalisation, rescue strategies such as balloon angioplasty and stenting are frequently employed. In this study, we aimed to investigate the comparative efficacy and safety of these strategies.
Methods
We retrospectively analysed the data of 321 patients with ICAS-related large vessel occlusion (LVO) treated with rescue balloon angioplasty (n=212) or stenting (n=109) after MT. The primary outcome was favourable outcomes (modified Rankin Scale score of 0–2) at 3 months. Multivariate logistic regression identified predictors of outcomes, including subgroup analyses for anterior and posterior circulation.
Results
Overall, data of 321 patients (median age, 60 (IQR, 53–67) years; 80.4% male) were analysed from an initial cohort of 1601 patients. At 3 months, the balloon group demonstrated a trend towards a higher rate of favourable outcomes (34.9% vs 45.8%; OR 0.62, 95% CI 0.36 to 1.09, p=0.098). The stent group showed a trend towards a higher incidence of symptomatic intracranial haemorrhage (11.0% vs 4.2%; OR 2.22, 95% CI 0.80 to 6.14, p=0.124). In the posterior circulation subgroup, favourable outcomes were significantly lower in the stent group (20.5% vs 41.5%; OR 0.32, 95% CI 0.10 to 0.98, p=0.047).
Conclusion
Balloon angioplasty after MT may improve clinical outcomes to some extent in ICAS-related LVO with a lower incidence of intracranial haemorrhage compared with stenting, while stenting is an effective measure to prevent long-term restenosis.
Keywords: Angioplasty, Thrombectomy, Stents, Stroke
WHAT IS ALREADY KNOWN ON THIS TOPIC
Mechanical thrombectomy (MT) is the first-line treatment for acute large vessel occlusion (LVO). Observational studies have suggested that rescue therapy after MT is superior to medical management in treating intracranial atherosclerotic stenosis-related LVO; however, the recent Randomized Study of Bailout Intracranial Angioplasty Following Thrombectomy for Acute Large Vessel Occlusion (ANGEL-REBOOT) study has not confirmed these findings, and limited studies have compared the two most common rescue strategies.
WHAT THIS STUDY ADDS
To the best of our knowledge, this study is the first to compare the effectiveness, safety and long-term restenosis rate between stenting and angioplasty as rescue therapies. Compared with stenting, we believe that submaximal balloon angioplasty should be the preferred rescue strategy.
HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY
This study’s findings indicate that the preferential use of balloon angioplasty as rescue therapy may be reasonable; however, further investigations of the effectiveness and safety of balloon angioplasty and stenting as rescue therapies are needed.
Introduction
Acute ischaemic stroke is a highly disabling disease, and mechanical thrombectomy (MT) is the first-line therapy for large vessel occlusion (LVO) in the anterior circulation.1 2 Intracranial atherosclerotic stenosis (ICAS), a common cause of failed MT,3 contributes to a higher rate of acute LVO in Asia than in Europe and North America.4 ICAS increases the risk of distal embolisation and early reocclusion after MT because of platelet activation from arterial plaques or endothelial damage, which is linked to poor outcomes.5,7 Observational studies have shown significant benefits of rescue therapy for patients with failed recanalisation.8,13 However, the recent Randomized Study of Bailout Intracranial Angioplasty Following Thrombectomy for Acute Large Vessel Occlusion ANGEL-REBOOT study14 demonstrated no advantage of rescue therapy over the standard medical management after MT, which may be related to the higher rate of complications in the rescue group. Balloon angioplasty and stenting are the primary rescue strategies for poor recanalisation after MT. However, studies directly comparing balloon angioplasty and stenting as rescue strategies are currently lacking. Therefore, we aimed to compare the effectiveness, safety and long-term restenosis ratios of both rescue strategies.
Methods
Patients
We conducted a retrospective analysis of clinical and imaging data from 321 patients with acute LVO who underwent either simple balloon angioplasty or stenting after MT between June 2018 and January 2024. The study Ethics Committee approved this study (23K177-001). All participants provided written informed consent. The inclusion criteria were as follows: (1) acute LVO within 24 hours; (2) patients aged >18 years with a prestroke modified Rankin Scale (mRS) score of 0–1 and a baseline National Institutes of Health Stroke Scale (NIHSS) score of ≥6; (3) a CT or diffusion-weighted imaging-based Alberta Stroke Program Early CT Score (ASPECTS) of ≥6, along with classification under the Trial of ORG 10 172 in Acute Stroke Treatment criteria indicating large-artery atherosclerosis; (4) the responsible vessel involved the intracranial segment of the internal carotid artery, the M1 and M2 segments of the middle cerebral artery, or the basilar artery and vertebrobasilar junction and (5) unsuccessful recanalisation (expanded Thrombolysis in Cerebral Infarction (eTICI) score of 0–2 a) or residual stenosis of >70% after MT. The exclusion criteria were as follows: (1) severe diseases before or during MT that may have affected clinical outcomes; (2) previous endovascular treatment for severe stenosis in the responsible vessel or on the same side as the responsible vessel (the internal carotid, middle cerebral, vertebral or basilar arteries) and (3) no 3-month postoperative mRS score (figure 1).
Figure 1. Patient allocation flowchart. This figure details the process of patient allocation to the balloon group and the stent group. MT, mechanical thrombectomy.
Endovascular procedure
According to the Chinese Stroke Guidelines, the patients were not given a loading dose of aspirin and clopidogrel before thrombectomy. Patients underwent the endovascular procedure under general or local anaesthesia. An 8F arterial sheath was used for right femoral artery access, and an 8F guiding catheter or 6F long sheath (Neuron MAX, AXS infinity LS) was advanced to the C1 segment of the internal carotid artery or end of segment V2 of the vertebral artery. A microguidewire, microcatheter and aspiration or intermediate catheter were delivered through the 8F catheter or 6F long sheath. Thrombectomy was performed using either a stent retriever (the Solitaire FR/Platinum, the Trevo, the Embotrap II), an aspiration catheter (the Catalyst 6, the REACT 68/71 and the ACE 60/68) or an integration of both. When the eTICI score was ≤2 a or severe stenosis remained after MT, the microguidewire was delivered through the aspiration or intermediate catheter to cross the lesion site. The balloon with a diameter of 80% of the vessel diameter was delivered to the lesion site, with the ends of the balloon completely covering both ends of the lesion. The balloon was slowly inflated to nominal pressure (the Gateway balloon (3atm) and the Sino Balloon (6atm)) for 60 s and then slowly deflated. After 10 min of observation, if the eTICI score was ≥2b50 and no reocclusion or severe stenosis was observed, the procedure was terminated. In cases of severe dissection or significant restriction of blood flow after angioplasty, a stent (the Solitaire FR, the APOLLO) was placed. In the stent group, the surgery was performed in the same manner with a stent (the APOLLO, the Solitaire FR) implanted in the target vessel. Surgical success criteria were defined as achieving residual stenosis of ≤70% with eTICI ≥2b50. Based on the patient’s condition and the operators’ experience, an initial intra-arterial loading dose of tirofiban (0.4 µg/(kg·min)) was administered for 30 min, followed by a continuous intravenous infusion at a maintenance dose of 0.1 µg/(kg·min) for 24–48 hour. If a CT scan performed 24 hours after the endovascular procedure ruled out cerebral haemorrhage, tirofiban was discontinued and the patient was transitioned to oral dual antiplatelet therapy (aspirin, 100 mg/day and clopidogrel, 75 mg/day).
Follow-up and data collection
After excluding intracranial haemorrhage (ICH), the patients were advised to initiate oral aspirin (100 mg/day) and clopidogrel (75 mg/day) therapy for 3 months postdischarge. For patients who were resistant to clopidogrel, ticagrelor (180 mg/day) was used. Patients with stroke risk factors, including hypertension and diabetes, managed their conditions with medication, which was adjusted based on their status during follow-up. Follow-up at 1, 3, 6 and 12 months after discharge was conducted through telephone or outpatient consultation. Patients were advised to undergo transcranial Doppler ultrasonography for vascular assessment at 1, 3, 6 and 12 months postdischarge. Data collected included patient demographics, clinical information, imaging results, surgical details and follow-up data.
Outcome measures
The primary validated endpoint was favourable outcomes at 3 months. Secondary validated endpoints included severe restenosis at 6 months, symptomatic restenosis and technical success, among others. The primary safety endpoint was symptomatic ICH. Secondary safety endpoints included any ICH, 90-day mortality and perioperative complications.
A favourable outcome was defined as an mRS score of ≤2. Reperfusion status was assessed using the eTICI scores.15 Successful reperfusion was defined as an eTICI score of ≥2b50. Severe restenosis was defined as a recurrence of stenosis of ≥70% over time, with the stenosis being within 5 mm of the treated site. Symptomatic restenosis was defined as treated-site stenosis ≥70% with ischaemic symptoms. Refractory occlusion14 was defined as unsuccessful recanalisation (an eTICI score of 0–2 a) after at least three attempts with conventional thrombectomy. Symptomatic ICH was defined as cerebral haemorrhage on imaging and an elevated NIHSS score of ≥4, according to the European Co-operative Acute Stroke Study-II (ECASS II) study.16 Any ICH was defined as cerebral haemorrhage on imaging after the procedure, whether symptomatic or asymptomatic. Severe dissection is defined as a dissection that significantly affects blood flow during the 15–20 min observation period following its occurrence.
Statistical analysis
Statistical analyses were performed using IBM SPSS Statistics for Windows, V.27.0 (IBM Corps, Armonk, New York). Data normality was assessed using the Shapiro–Wilk test. Data following a normal distribution are presented as the mean±SD, and groups were compared using independent sample t-tests. Non-normally distributed data are presented as medians (IQR), and comparisons between groups were performed using the Wilcoxon rank-sum test. Categorical variables are expressed as frequencies and constituent ratios and were compared using the χ2 test or Fisher’s exact test. Binary logistic regression analysis was used to predict outcomes. Statistical significance was set at p<0.05.
Results
Baseline and procedural characteristics
Overall, 321 patients were included in the analysis, and all patients were of Asian ethnicities, with a median age of 60 (53–67) years. Most patients were men (80.4%). Stroke risk factors in the population included hypertension (68.2%), hyperlipidaemia (34.3%) and diabetes (26.8%) in the population. A prior history of transient ischaemic attack (TIA) or stroke was found in 25.9% of the patients. The median time from onset to puncture was 477 (345–770) min. Most lesions were in the middle cerebral artery (39.3%). Thrombolysis was performed preoperatively in 10.9% of patients, and 5.0% of all patients had tandem lesions (table 1). Refractory occlusions were found in 4.4% of patients.
Table 1. Baseline demographic and clinical characteristics between the balloon and stent groups.
| All patients (n=321) | Balloon (n=212) | Stent (n=109) | P value | |
|---|---|---|---|---|
| Demographics | ||||
| Age, year, median (IQR) | 60.00 (53.0–67.0) | 59.0 (52.0–66.5) | 61.0 (55.0–68.0) | 0.057 |
| Race, Asian, n (%) | 321 (100.0%) | 212 (100.0%) | 109 (100.0%) | 1.000 |
| Sex male, n (%) | 258 (80.4%) | 165 (77.8%) | 93 (85.3%) | 0.138 |
| Vascular risk factors | ||||
| Smoking, n (%) | 156 (48.6%) | 105 (49.5%) | 51 (46.8%) | 0.724 |
| Drinking, n (%) | 135 (42.1%) | 94 (44.3%) | 41 (37.6%) | 0.283 |
| Coronary heart disease, n (%) | 38 (11.8%) | 28 (13.2%) | 10 (9.2%) | 0.363 |
| Atrial fibrillation, n (%) | 8 (2.5%) | 5 (2.4%) | 3 (2.8%) | 1.000 |
| Hypertension, n (%) | 219 (68.2%) | 141 (66.5%) | 78 (71.6%) | 0.378 |
| Diabetes mellitus, n (%) | 86 (26.8%) | 57 (26.9%) | 29 (26.6%) | 1.000 |
| Hyperlipidaemia, n (%) | 110 (34.3%) | 79 (37.3%) | 31 (28.4%) | 0.136 |
| Wake-up stroke, n (%) | 70 (21.8%) | 52 (24.5%) | 18 (16.5%) | 0.117 |
| Previous stroke, n (%) | 83 (25.9%) | 59 (27.8%) | 24 (22.0%) | 0.284 |
| Clinical data | ||||
| SBP, mm Hg, median (IQR) | 152.0 (138.0–169.0) | 152.0 (137.0–170.0) | 151.0 (140.0–165.0) | 0.649 |
| DBP, mm Hg, median (IQR) | 88.0 (79.0–98.0) | 88.0 (79.0–98.0) | 89.0 (80.0–98.0) | 0.536 |
| Baseline NIHSS, median (IQR) | 13.0 (9.0–17.0) | 13.0 (9.0–16.5) | 13.0 (9.0–17.0) | 0.535 |
| Baseline ASPECTS, median (IQR) | 8.0 (7.0–9.0) | 8.0 (7.0–9.0) | 8.0 (7.0–9.0) | 0.040 |
| Onset to puncture time, min, median (IQR) | 477.0 (345.0–770.0) | 464.5 (332.0–738.5) | 545.0 (360.0–840.0) | 0.055 |
| Puncture to recanalisation time, min, median (IQR) | 79.0 (60.0–110.0) | 75.0 (56.0–105.0) | 80.0 (63.0–119.0) | 0.045 |
| Procedure characteristics | ||||
| Occlusion site | 0.469 | |||
| Middle cerebral artery M1, n (%) | 126 (39.3%) | 80 (37.7%) | 46 (42.2%) | |
| Intracranial internal carotid artery, n (%) | 62 (19.3%) | 38 (17.9%) | 24 (22.0%) | |
| Basilar artery, n (%) | 80 (24.9%) | 58 (27.4%) | 22 (20.2%) | |
| Vertebrobasilar junction, n (%) | 53 (16.5%) | 36 (17.0%) | 17 (15.6%) | |
| Type of anaesthesia, local anaesthesia, n (%) | 129 (40.2%) | 100 (47.2%) | 29 (26.6%) | <0.001 |
| First-line thrombectomy | 0.245 | |||
| Stent-retriever, n (%) | 8 (2.5%) | 5 (2.4%) | 3 (2.8%) | |
| Aspiration, n (%) | 30 (9.3%) | 24 (11.3%) | 6 (5.5%) | |
| Stent-retriever plus aspiration, n (%) | 283 (88.2%) | 183 (86.3%) | 100 (91.7%) | |
| Number of MT, median (IQR) | 1.0 (1.0–2.0) | 1.0 (1.0–2.0) | 1.0 (1.0–2.0) | 0.248 |
| Intravenous alteplase pretreatment, n (%) | 35 (10.9%) | 17 (8.0%) | 18 (16.5%) | 0.024 |
| Tandem lesion, n (%) | 16 (5.0%) | 10 (4.7%) | 6 (5.5%) | 0.790 |
| GPI, n (%) | 263 (81.9%) | 176 (83.0%) | 87 (79.8%) | 0.540 |
| Refractory occlusion, n (%) | 14 (4.4%) | 9 (4.2%) | 5 (4.6%) | 1.000 |
ASPECTS, Acute Stroke Prognosis Early CT Score; DBP, diastolic blood pressure; GPI, glycoprotein IIb/IIIa Inhibitors; HR, heart rate; MT, mechanical thrombectomy; NIHSS, National Institutes of Health Stroke Scale; SBP, systolic blood pressure; TIA, transient ischaemia attack.
Of the 321 patients, the balloon group included 212 and the stent group included 109 patients. Age, sex, systolic and diastolic blood pressure, hypertension, diabetes, hyperlipidaemia, atrial fibrillation, coronary artery disease, smoking, drinking, mode of disease onset, baseline NIHSS, occlusion site, number of MT attempts, method of the first MT and use of glycoprotein IIb/IIIa inhibitors did not significantly differ between the two groups. In the balloon group, 30 patients (14.2%) underwent rescue stenting after balloon angioplasty; 14 patients (6.6%) due to severe dissection and 16 (7.5%) due to a high risk of reocclusion. A smaller proportion of patients in the balloon group received intravenous thrombolysis before endovascular thrombectomy (8.0% vs 16.5%, p=0.024). The proportion of patients undergoing endovascular therapy (EVT) under local anaesthesia was significantly higher in the balloon group than in the stent group (47.2 vs 26.6, p<0.001). The median operation times were 75 (quartile, 56–105) min and 80 (quartile, 63–119) min in the balloon and stent groups, respectively. The frequency of primary EVT methods was also similar between the two groups; stent retrievers with aspiration were mostly used in the angioplasty and stenting groups (86.3% vs 91.7%) (table 1).
Clinical and imaging outcomes
Finally, 45.8% and 34.9% of patients in the balloon and stent groups, respectively, achieved an mRS score of 0–2 (figure 2). In the stent group, the rate of any ICH was 30.3%, with an 11.0% rate of symptomatic cerebral haemorrhage (sICH). In the balloon group, the rate of any ICH was 16.5%, with a 4.2% rate of sICH. Vessel dissection was observed in 35 patients (16.5%) in the balloon group, and 14 of them (6.6%) underwent rescue stenting. The incidence of vascular dissection was higher in the balloon group than in the stent group (16.5% vs 5.5%), while the incidence of vascular perforation was lower in the balloon group than in the stent group (0.0% vs 1.8%). The ≥50% rate of residual stenosis was higher in the balloon group (22.6%) than in the stent group (4.6%). The mean degree of stenosis after EVT in the balloon group was 38.7%, which was higher than that in the stent group (24.7%). In the stent group, none of the patients had >70% stenosis, and five had a stenosis of >50% with the SOLITAIRE FR stent. The restenosis rate was higher in the balloon group than in the stent group 6 months after the endovascular procedure (30.4% vs 7.3%, p=0.004). The symptomatic restenosis rate did not differ significantly (3.6% vs 2.4%) (table 2).
Figure 2. Distribution of modified Rankin Scale score at 3 months. This figure shows the distribution of mRS scores for patients in the balloon group and the stent group at 3 months. In the figure, the number of patients in the balloon group with an mRS score of 0–2 is higher than that in the stent group.
Table 2. Procedure characteristics and outcomes between the balloon and stent groups.
| All patients (n=321) |
Balloon (n=212) |
Stent (n=109) |
P value | aOR (95% CI) |
P value | |
|---|---|---|---|---|---|---|
| Primary safety endpoint | ||||||
| sICH within 24 hours, n (%) | 21 (6.5%) | 9 (4.2%) | 12 (11.0%) | 0.030 | 2.22 (0.80 to 6.14) | 0.124 |
| Secondary safety endpoints | ||||||
| Mortality within 3 months, n (%) | 56 (17.4%) | 36 (17.0%) | 20 (18.3%) | 0.877 | NA | NA |
| Any ICH within 24 hours, n (%) | 68 (21.2%) | 35 (16.5%) | 33 (30.3%) | 0.006 | NA | NA |
| Vessel dissection, n (%) | 41 (12.8%) | 35 (16.5%) | 6 (5.5%) | 0.007 | 0.36 (0.14 to 0.94) | 0.037 |
| Vascular perforation, n (%) | 2 (0.6%) | 0 (0.0%) | 2 (1.8%) | 0.115 | NA | NA |
| Re-occlusion in procedure, n (%) | 4 (1.2%) | 4 (1.9%) | 0 (0.0%) | 0.304 | NA | NA |
| Distal embolisation, n (%) | 32 (10.0%) | 20 (9.4%) | 12 (11.0%) | 0.696 | NA | NA |
| Primary efficacy endpoint | ||||||
| Favourable outcome (mRS ≦2) at 3 months, n (%) | 135 (42.1%) | 97 (45.8%) | 38 (34.9%) | 0.073 | 0.62 (0.36 to 1.09) | 0.098 |
| Secondary efficacy endpoints | ||||||
| Restenosis (≥70%) at 6 months, n (%) | 45/179 (25.1%) | 42/138 (30.4%) | 3/41 (7.3%) | 0.004 | 0.20 (0.05 to 0.78) | 0.020 |
| Symptomatic restenosis, n (%) | 6/179 (3.4%) | 5/138 (3.6%) | 1/41 (2.4%) | 1.000 | NA | NA |
| eTICI (≥2b50), n (%) | 298 (92.8%) | 194 (91.5%) | 104 (95.4%) | 0.256 | NA | NA |
| Technical success, n (%) | 288 (89.7%) | 187 (88.2%) | 104 (95.4%) | 0.042 | NA | NA |
| Immediate stenosis (≥50%) after operation, n (%) | 53 (16.5%) | 48 (22.6%) | 5 (4.6%) | <0.001 | 0.12 (0.04 to 0.34) | <0.001 |
| NIHSS at 24 hours after operation, n (%) | 10.0 (5.0–15.0) | 9.0 (5.0–14.0) | 10.0 (6.0–16.0) | 0.274 | NA | NA |
Adjusted for age, gender, diabetes, hypertension, hyperlipidaemia, smoking, lesion site, baseline NIHSS, baseline ASPECT, coronary heart disease, history of TIA or stroke, drinking, time of onset to puncture, IIb/IIIa application, intravenous alteplase pretreatment, type of anaesthesia, number of MT attempts and atrial fibrillation.
ASPECTS, Alberta Stroke Program Early CT Score; eTICI, expended thrombolysis in cerebral infarction; ICH, intracranial haemorrhage; MT, mechanical thrombectomy; NA, not available; NIHSS, National Institutes of Health Stroke Scale; sICH, symptomatic ICH according to ECASS II; TIA, transient ischaemia attack.
At 6 months, in the balloon group, 42/138 (30.4%) patients had severe stenosis, with 5/138 (3.6%) having ischaemic symptoms related to the affected vessel. In the stent group, 3/41 (7.3%) patients had severe stenosis, with 1/41 (2.4%) having ischaemic symptoms (table 2).
After adjusting for age, sex, diabetes, hypertension, hyperlipidaemia, smoking, lesion site, baseline NIHSS, baseline ASPECTS, coronary heart disease, history of TIA or stroke, drinking, time of onset to puncture, glycoprotein IIb/IIIa application, intravenous alteplase pretreatment, type of anaesthesia, number of MT attempts and atrial fibrillation and rescue strategies; multivariate regression analysis identified baseline NIHSS (OR) 1.08; 95% CI 1.04 to 1.12; p<0.001), diabetes (OR 2.80, 95% CI 1.51 to 5.21; p=0.001), and number of MT attempts (OR 1.29, 95% CI 1.03 to 1.63; p=0.028) as independent predictors of favourable outcomes at 3 months and identified rescue strategy (OR 0.20, 95% CI 0.05 to 0.78; p=0.02) as an independent predictor of recurrent restenosis at 6 months after EVT.
Subgroup analyses
The 212 and 109 patients in the balloon and the stent groups, respectively, were further compared to evaluate the effectiveness and safety of balloon angioplasty and stenting in both anterior and posterior circulations (online supplemental table S1). In the anterior circulation, the technical success rate was slightly lower in the balloon group than in the stent group (85.6% vs 94.3%). The 3-month favourable prognosis rate was higher in the balloon group than in the stent group (49.2% vs 42.9%; OR 1.11, 95% CI 0.50 to 2.47; p=0.793); however, this was not statistically significant (online supplemental table S2).
In the posterior circulation, similar technical success was observed in the balloon and stent groups (91.5% vs 97.4%). The 3-month good prognosis rate was significantly higher in the balloon group than in the stent group (41.5% vs 20.5%; OR 3.15, 95% CI 1.02 to 9.77; p=0.047, p interaction=0.162). The rate of sICH was lower in the balloon group than in the stent group (3.2% vs 12.8; OR 0.23, 95% CI 0.03 to 1.64; p=0.146); however, this was not statistically significant (online supplemental table S2).
Discussion
Recent studies8,14 have examined rescue therapies following failed MT to restore perfusion (eTICI<2b50) or address the stenosis of >70%; however, results have been inconsistent. In this study, we compared balloon angioplasty and stenting as rescue therapies in 321 patients. The balloon group had a higher rate of favourable outcomes (mRS≤2) at 3 months and a lower incidence of sICH. Although the rate of restenosis at 6 months was significantly higher in the balloon group, symptomatic restenosis rates were similar between both groups.
A meta-analysis5 showed that successful recanalisation resulted in a higher favourable outcome rate (58.1% vs 24.8%; OR 4.43, 95% CI 3.32 to 5.91). Poor reperfusion correlates with worse outcomes or death within 3 months.17 Some studies9 10 have suggested that rescue therapy is both safe and effective. For instance, Mohammaden et al11 reported that rescue stenting improved outcomes (mRS ≤2, 35.1% vs 7%) without increasing ICH risk. Conversely, a multicentre randomised controlled trial14 demonstrated that rescue therapy did not improve outcomes for patients compared with standard treatment (mRS ≤2, 55% vs 57%). The possible reasons for this could be as follows: first, 71% of patients in the control group achieved good recanalisation (eTICI≥2b50) compared with 64% in the intervention group before assignment. Second, the control group received additional MT sessions or tirofiban,7 leading to a higher recanalisation rate, which may have contributed to better outcomes. Finally, the intervention group had a higher complication rate (30% vs 18%) and a higher incidence of sICH (5% vs 1%), which may have diminished the benefits of rescue therapy.
A small study (n=23)18 found that balloon angioplasty alone after MT was more beneficial than stenting, with a 100% favourable outcome (mRS ≤2) in the balloon group compared with 37.5% in the stent group. However, the small sample size and the inclusion of rescue stenting after failed balloon angioplasty in the stent group may introduce bias into the results. Another study19 reported a lower 3-month favourable outcome rate in the balloon group than in the stent group (37% vs 56%) and a lower recanalisation rate (61% vs 87%) in the balloon group. These results differ from those of previous studies,20 21 and the lower recanalisation rate, along with more MT attempts in the balloon group, may have contributed to poorer outcomes.
This study suggests that balloon angioplasty had more favourable outcomes at 3 months, likely due to the lower sICH and any ICH rates.22 The stent group’s lower residual stenosis and a more aggressive antiplatelet strategy may have contributed to a higher risk of overperfusion and complications. Additionally, a higher proportion of patients in the stent group underwent intravenous thrombolysis before endovascular treatment, which may be one of the reasons for the higher ICH rate in the stent group. In the balloon group, the higher residual stenosis may have limited blood flow, thereby reducing the risk of ICH caused by hyperperfusion. Notably, the subgroup analysis showed no significant difference in the rate of favourable outcomes between the two groups (49.2% vs 42.9%) in patients with anterior circulation stroke. However, in the posterior circulation, the rate of favourable outcomes was significantly higher in the balloon group than in the stent group (41.5% vs 20.5%). One possible explanation is the higher incidence of haemorrhage in the stent group. Compared with the anterior circulation, haemorrhage in the posterior circulation may result in more devastating neurological deficits.
Restenosis is one of the main problems encountered during EVT for ICAS. An increased degree of stenosis is associated with a higher stroke recurrence rate and poorer outcomes.23 Most success criteria for balloon angioplasty for ICAS24 25 require postoperative stenosis <50%. Here, achieving eTICI ≥2b50 was considered successful, even with residual stenosis of 50%–70% to prevent overperfusion injury. This may be the main reason why the rate of restenosis in the balloon group is higher than that in the BASIS study.26 In the balloon group, although the restenosis rate was 30.4%, only 3.6% of cases were associated with ischaemic symptoms, which is similar to the previously reported rate of symptomatic restenosis.24 A previous study27 suggested that most recurrences in symptomatic ICAS occur within 2 weeks. Balloon angioplasty may effectively improve flow insufficiency caused by vascular stenosis in the short term. Although stenosis may gradually worsen in the long term, collateral circulation could have already been well established during this period. This may explain why the rate of symptomatic restenosis is low in this group. Moreover, stenosis may improve in some patients during the vessel repair process. Here, a patient with severe stenosis after balloon angioplasty alone showed gradual improvement to mild stenosis at 1 year of follow-up. However, the restenosis rate in the balloon group was significantly higher than that in the stent group, which may result in a higher risk of stroke recurrence. Thus, we believe that these patients should undergo stenting within 6 months to prevent the risk of stroke recurrence due to restenosis. Notably, in the stent group, we did not use stents specifically designed to prevent long-term restenosis, which may have had some effect on the results.
Ultimately, while balloon angioplasty may present a higher restenosis rate, it could offer favourable outcomes with a lower risk of haemorrhage than stenting. The decision to use stenting should be carefully weighed against the potential risks, particularly when recanalisation is difficult.
Limitations
This study has some limitations. First, it was a retrospective study. Second, the choice of rescue strategy was determined by the operator; there was no standardised approach. Thus, different patient selection criteria may lead to discrepancies between the two groups, potentially influencing the clinical outcomes of the patients and affecting the conclusions of the study. Third, the significant difference in anaesthesia methods between the two groups may have had some impact on the results. Finally, the smaller size of the stent group may have affected the statistical results.
Conclusion
Balloon angioplasty after MT may improve clinical outcomes in ICAS-related LVO with a lower incidence of intracerebral haemorrhage than stenting, while stenting is an effective measure to prevent long-term restenosis. Both balloon angioplasty and stenting were similarly effective in preventing long-term ischaemic symptoms. Therefore, for patients with failed thrombectomy, prioritising balloon angioplasty as the rescue strategy may be an acceptable approach, while stenting could serve as a long-term measure to prevent restenosis.
Supplementary material
Acknowledgements
The authors thank Editage for language editing.
Footnotes
Funding: This project was supported by the Beijing Medical Award Foundation (grant number YXJL–2022–1211–0419).
Provenance and peer review: Not commissioned; externally peer-reviewed.
Patient consent for publication: Not applicable.
Ethics approval: This study involves human participants and was approved by the Medical Ethics Committee of the First Hospital of Jilin University (23K177-001). Participants gave informed consent to participate in the study before taking part.
Data availability statement
Data are available upon reasonable request.
References
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Data Availability Statement
Data are available upon reasonable request.