A novel approach to embolic protection during stent-retriever mechanical thrombectomy that employs both proximal flow arrest and distal aspiration compares favorably to distal aspiration alone, researchers show in a case-control study published online last month ahead of print in the Journal of NeuroInterventional Surgery.
The novel technique is known as PROTECT (PRoximal balloon Occlusion TogEther with direCt Thrombus aspiration).
“We are using a large bore distal aspiration catheter which is advanced as closely as possible to the thrombus before performing the stent retriever maneuver,” write the authors, led by Christian Maegerlein, MD (Technical University Munich, Munich, Germany). “During stent retriever retraction, aspiration is applied to the distal aspiration catheter to facilitate opening the occlusion site while avoiding distal embolizations or embolizations to new, previously uninvolved vascular territories.”
In addition, PROTECT involves inserting a large-bore aspiration catheter into the balloon-guide catheter and applying “both proximal aspiration/flow reversal and distal aspiration during the stent retriever maneuver,” they explain, adding that the approach became possible as catheters of up to 6-FR could be inserted into balloon-guide catheters.
Maegerlein and colleagues compared the PROTECT technique with sole distal aspiration in a case-control study. Overall, 200 patients with emergent large vessel occlusion of the internal carotid artery terminus or the proximal middle artery terminus were treated with mechanical thrombectomy with the addition of the PROTECT technique (n = 40) or distal aspiration (n = 160).
Patients treated with the PROTECT technique had a significantly shorter procedure time as well as higher rates of successful recanalization and complete reperfusion compared with sole distal aspiration.
Outcomes of Mechanical Thrombectomy by Type of Protection
|
|
PROTECT (n = 40) |
Distal Aspiration (n= 160) |
P Value |
|
Median Procedure Time, mins |
29 |
40 |
0.002 |
|
TICI 2b/3 |
100% |
78% |
0.001 |
|
Complete Reperfusion |
70% |
39% |
< 0.001 |
The authors point out that the outcomes seen with PROTECT are superior to those seen in studies in which conventional balloon-guided catheter techniques were used, such as a recent meta-analysis that yielded a successful recanalization rate of 79% in 1,083 patients.
PROTECT compares even more favorably to studies in which no embolic protection is used with stent-retriever thrombectomy, and the authors conclude that the latter should therefore be considered obsolete. “This ostensibly easier approach often turns out to be more complicated,” they write, “as additional salvage maneuvers due to thrombus fragmentations and distal embolizations are required without the certainty of finally reaching a favorable result and additionally increasing the risks of periprocedural complications.”
Maegerlein et al acknowledge their study’s limitations, which include its retrospective, observational nature and use of different stent retrievers and aspiration catheters at variable positions. Nevertheless, they conclude, “the PROTECT technique is a promising new approach to significantly reduce thrombus fragmentation and, hence distal embolization during [mechanical thrombectomy]. This safe and efficient technique needs to be validated in larger trials to confirm our results.”
Source:
Maegerlein C, Mönch S, Boeckh-Behrens T, et al. PROTECT: PRoximal balloon Occlusion TogEther with direCt Thrombus aspiration during stent retriever thrombectomy - evaluation of a double embolic protection approach in endovascular stroke treatment. J NeuroInterv Surg. 2017;Epub ahead of print.
Disclosures:
Maegerlein reports no relevant conflicts of interest.
