Table 2.
Selected studies reporting the association between pre-treatment collateral status and outcomes after EVT of anterior circulation large vessel occlusion stroke
| Study | Patients (n) | Collateral scale (method) | Main findings |
|---|---|---|---|
| Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke trials (HERMES) collaboration [75] | 1,764 (871 EVT, 893 control) | Tan et al. [76] (sCTA, mCTA, or CE-MRA) | Analyses suggested benefit with EVT across all strata of collateral circulation status; however, patients with poor collaterals were less likely to benefit from EVT than those with better collaterals (not statistically significant). |
| Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke (DEFUSE 3) trial [77] | 130 (65 EVT, 65 control) | Tan et al. [76] (sCTA, mCTA, or CE-MRA) | No significant association with good clinical outcome*, sICH, or death. Good collaterals were associated with significantly smaller ischemic core volume and less ischemic core growth. |
| Diffusion-Weighted Imaging or Computed Tomography Perfusion Assessment With Clinical Mismatch in the Triage of Wake-Up and Late Presenting Strokes Undergoing Neurointervention With Trevo (DAWN) trial [92] | 161 (91 EVT, 70 control) | Tan et al. [76] (CTA) | Significant association between collateral status and infarct core at 24 h, ASPECTS at 24 h, successful revascularization (eTICI ≥2b), good functional outcome*, and death. |
| ASITN/SIR [78] (DSA) | |||
| Gerber et al. [79] | 93 | Tan et al. [76] | Good collaterals were significantly associated with good clinical outcome* (OR 9.69; 95% CI 2.28–59.27; P=0.001). |
| Sedation versus Intubation for Endovascular Stroke TreAtment (SIESTA) trial [80] | 104 | Tan et al. [76] | Good collaterals were significantly associated with smaller final infarct volume, improvement in the mean NIHSS at 24 h, and in-house mortality. No significant association was found with functional outcome or 3-month mortality. |
| Sallustio et al. [81] | 135 | Tan et al. [76] (CTA) | Significant association between good collaterals and good functional outcome* (OR 2.13; 95% CI 1.44 to 3.15; P<0.001), lower mortality rate, lower rate of sICH, higher ASPECTS at 24 h, and higher NIHSS improvement at 24 h. |
| Christoforidis et al. [82] (DSA) | |||
| Park et al. [83] | 119 | Regional colateral scoring system [84] | Good collaterals were an independent predictor of good functional outcome* (OR 5.14; 95% CI 1.62–16.26; P=0.005). |
| Renú et al. [85] | 339 (257 EVT, 82 no EVT) | Tan et al. [76] | The benefit of EVT (reduction in infarct growth, functional outcome, and mortality) was significantly higher in patients with poor collaterals. |
| Weiss et al. [86] | 84 | Tan et al. [76] (sCTA) | Good collaterals in the Miteff and Maas scores were significantly associated with good functional outcome*. |
| Miteff et al. [87] (sCTA) | |||
| Maas et al. [88] (sCTA) | |||
| Al-Dasuqi et al. [89] | 283 | Miteff et al. [87] (sCTA) | Collateral grade was significantly associated with final infarct volume but not with functional outcome. |
| Optimizing Patient’s Selection for Endovascular Treatment in Acute Ischemic Stroke (SELECT) study [90] | 361 (285 EVT, 76 medical management) | mCTA [40] | Collateral status was significantly associated with early infarct growth rate which in turn was significantly associated with functional outcome. |
| Endovascular Treatment in Ischemic Stroke (ETIS) Registry [91] | 2,020 | ASITN/SIR (DSA) | Good collaterals were associated with successful reperfusion (OR 1.77; 95% CI 1.32–2.39; P<0.001), excellent reperfusion (OR 1.71; 95% CI 1.41–2.09; P<0.001), and good functional outcome* (OR 1.5; 95% CI 1.19–1.88; P<0.001), but not with sICH or mortality at 3 months. |
EVT, endovascular thrombectomy; sCTA, single-phase computed tomography angiography; mCTA, multiphase computed tomography angiography; CE-MRA, contrast-enhanced magnetic resonance angiography; sICH, symptomatic intracranial hemorrhage; CTA, computed tomography angiography; ASITN/SIR, American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology scale; DSA, digital subtraction angiography; ASPECTS, Alberta Stroke Program Early CT Score; eTICI, expanded Thrombolysis in Cerebral Infarction; OR, odds ratio; CI, confidence interval; NIHSS, National Institutes of Health Stroke Scale; mRS, modified Rankin Scale.
*
Good functional outcome: mRS ≤2 at 90 days.