One expert cautioned against widespread adoption, though, because most neurointerventionalists are unfamiliar with using catheters without guidewires.
Use of a wireless microcatheter technique to pass clots during stent retriever thrombectomy in acute ischemic stroke may be associated with a lower complication rate, according to data from a single-center series.
“The authors propose a wireless microcatheter technique to reduce the incidence of vessel injury resulting in vessel perforation and subarachnoid hemorrhage during mechanical thrombectomy procedures,” Perry P. Ng, MD (CHPG Neurosciences and Spine, Lakewood, CO), commented to Neurovascular Exchange in an email. “Frank extravasation from iatrogenic vessel injury during the procedure usually portends a bad prognosis and can be fatal, while limited subarachnoid hemorrhage found on post-operative CT scans is usually benign but can still be of clinical significance, as we recently published in the Journal of NeuroInterventional Surgery.”
In an email, senior author Martin Wiesmann, MD (University Hospital Aachen, Germany), told NVX the technique is fairly simple. “Neurointerventionalists who are willing to train [to do] it and apply it in their stroke cases can expect that their complication rates will go down, and their patients will benefit,” he anticipated.
In the single-center experience, investigators led by Annika Keulers, MD, (University Hospital Aachen), conducted a retrospective analysis of 110 consecutive patients treated for anterior circulation acute ischemic stroke for whom a video recording of mechanical thrombectomy was available.
Overall, 203 attempts at mechanical recanalization were performed. Successful recanalization, defined as a TICI 2b/3, was achieved in 97.3% of patients.
Among the 67 patients in whom the initial attempt was made using a microwire, complete recanalization was achieved with one pass in 95.5%. Among the 124 attempts made initially using a wireless microcatheter, 71.8% achieved complete recanalization in the first pass.
Complication rates for angiographically-detectable subarachnoid hemorrhage were 6.1% with a microwire and 0% with a wireless microcatheter (P < 0.001). Complication rates for angiographically-occult circumscribed subarachnoid contrast extravasation observed on postinterventional CT scans were 18.2% when a microwire was used and 4.5% with a wireless microcatheter (P < 0.001).
“As evidenced by our study, passing the clot with a wireless microcatheter is significantly safer than the standard technique,” Wiesmann said. With currently available microcatheters, this approach was not feasible in nearly 28% of cases, but “if the technique works, the risk of perforation goes down to almost zero,” he added.
More Experience, Detailed Descriptions of Technique Needed
Commenting to NVX, however, Ng was not quite as confident. While he applauded the investigators’ extremely high rate of successful recanalization, he also noted that “the use of any catheter without a guidewire is contrary to standard endovascular technique [and] outside of the use of flow-directed microcatheters for high-flow vascular malformations. The technique may not be familiar to many interventionalists.
“Moreover, the ability to steer the microcatheter into a specific branch is lost without the use of a guidewire,” he continued. “Microcatheters are also stiffer than guidewires and less able to follow acute turns in vessels which can result in vessel injury.”
Ng expressed concern that outcomes may not be as positive if the procedure were to be adopted in a lower-volume stroke center by interventionalists with less-extensive experience.
“I would caution against the widespread adoption of their proposed technique, as most neurointerventionalists are unfamiliar with using catheters without guidewires and do not have as much experience with stroke thrombectomy as the authors in this paper,” he said. “Moreover, the paper does not provide any details as to how to tackle different clot lengths and vessel curvatures without a guidewire, how much force to apply to the microcatheter when resistance to advancement is met, etc. I think more description about the actual technique is required before the technique can be recommended.”
He suggested that it could currently be adopted by experienced interventionalists treating a short segment of thrombus along a relatively straight vessel segment.
“We would welcome a prospective, randomized confirmation of our data, said Weisman. “However, our results are very clear, and it may be difficult to justify randomizing patients to an obviously inferior technique.”
Source:
Keulers A, Nikoubashman O, Mpotsaris A, et al. Preventing vessel perforations in endovascular thrombectomy: Feasibility and safety of passing the clot with a microcatheter without microwire: the wireless microcatheter technique. J NeuroIntervent Surg. 2018;Epub ahead of print.
Disclosures:
- Wiesmann reports receiving personal fees from Stryker Neurovascular, Siemens Healthcare, Bracco Imaging, and Medtronic outside the submitted work; and grants for educational exhibits (nonpersonal) from Abbott, ab medica, Acandis, Bayer, Bracco Imaging, B Braun, Codman Neurovascular, Kaneka Pharmaceuticals, Medtronic, Dahlhausen, Microvention, Penumbra, Phenox, Philips Healthcare, Route 92, Siemens Healthcare, SilkRoad Medical, St Jude, and Stryker Neurovascular.
- Ng reports no relevant conflicts of interest.
