Use of bridging therapy may delay time to puncture and increase the risk of intracranial hemorrhage without providing any clinical benefits for patients with carotid artery occlusions, according to a retrospective analysis published online recently ahead of print in the Journal of NeuroInterventional Surgery.
The authors, led by Romain Bourcier, MD (University Hospital of Nantes, Nantes, France), point out that retrospective studies have shown no benefit to adding bridging intravenous (IV) tPA to mechanical thrombectomy in patients with large vessel occlusions (LVOs). It remains unclear, however, if this holds true for patients specifically with internal carotid artery occlusions involving the middle cerebral artery and anterior cerebral artery because such patients were in the minority in the trials.
Bourcier and colleagues conducted a retrospective multicenter analysis of prospectively collected data on 141 consecutive patients treated between January 2014 and June 2016 for internal carotid artery terminus occlusions using mechanical thrombectomy. Overall, 85 received bridging therapy with IVA tPA and 56 received mechanical thrombectomy alone.
Baseline characteristics between the two groups of patients were similar. There were no significant differences between them with respect to rates of successful recanalization, distal emboli, and median number of passes. Patients who received bridging therapy, however, had a significantly longer median time between imaging and groin puncture and a higher rate of intracerebral hemorrhage (but not symptomatic intracerebral hemorrhage).
Outcomes of Mechanical Thrombectomy With and Without Bridging
|
|
With (n = 85) |
Without (n= 56) |
P Value |
|
TICI 2b/3 |
75% |
80% |
0.54 |
|
Distal Emboli |
21% |
27% |
0.43 |
|
Median Number of Passes |
3 |
2 |
0.21 |
|
Median Time from Imaging to Groin Puncture, mins |
97 |
75 |
0.007 |
|
Intracerebral Hemorrhage |
44% |
27% |
0.05 |
|
Symptomatic Intracerebral Hemorrhage |
18% |
13% |
0.49 |
“Patients given [IV thrombolysis] require specialized medical transfer from imaging suites to angiography suites,” write the authors. They speculate that the time required to organize this expert team likely accounts for the delay to puncture seen in the bridging therapy group. While transfer from other centers can also cause delays, they point out that the proportion of patients who were transferred in their study was similar in patients who did and did not receive bridging therapy.
Based on propensity analysis, the rate of mRS ≤ 2 at 3 months was similar for both groups (OR 1.6; 95% CI 0.7-3.7; P = 0.29 for bridging vs no bridging), and there was a trend toward higher rates of intracerebral hemorrhage with bridging (OR 2.3, 95% CI 0.9-5.9, P = 0.09).
“This study is the first to present results of [mechanical thrombectomy] with or without [IV thrombolysis] in a large number of patients with very proximal occlusion—that is, carotid terminus occlusion and high clot burden,” the authors point out. “Multicenter recruitment allowed for a large sample size from a broad spectrum of centers that reflects standard everyday practice of endovascular thrombectomy in stroke, although [internal carotid artery terminus occlusions] remain a subgroup of LVOs.”
They conclude that thrombolysis “provided no apparent benefits” here, whether the occlusions involved the middle or anterior cerebral artery, both, or none, and seemed to carry added risk. “Future large RCTs will probably provide more insight into the best strategy to use in proximal occlusions,” Bourcier and colleagues conclude.
Source:
Bourcier R, Alexandre PL, Eugène F, et al. Is bridging therapy still required in stroke due to carotid artery terminus occlusions? J NeuroInterv Surg. 2017;Epub ahead of print.
Disclosure:
Bourcier reports no relevant conflicts of interest.