Neurothrombectomy offers ‘intriguing’ stroke therapy option
MedWire News: Neurothrombectomy has potential for treating patients with ischemic stroke, but many knowledge gaps remain, say the authors of a literature review.
"Currently available neurothrombectomy devices offer intriguing treatment options in patients with acute ischemic stroke," Craig Coleman (Hartford Hospital, Connecticut, USA) and co-workers write in the Annals of Internal Medicine.
But they stress that "a paucity of high-quality research currently exists."
Of the 87 studies that met the team's eligibility criteria, 62 were case reports or series. The remaining studies comprised seven retrospective and 18 prospective studies, but all of these were single-group studies, ie, they did not directly compare neurothrombectomy with an alternative strategy.
Most data came from studies of two devices: the MERCI Retriever (Concentric Medical, Mountain View, California, USA) and the Penumbra System (Penumbra, Alameda, California).
However, Coleman et al note that research into neurothrombectomy in stroke patients is "still in its infancy." They say: "Identifying gaps in current knowledge and guiding future efforts is paramount."
The only predictor of good outcomes was successful recanalization; however, clinical outcomes were only reported in 68% of the studies. Reported rates of successful recanalization ranged from 43% to 78% with the MERCI Retriever and from 83% to 100% with the Penumbra System. Good outcomes occurred in up to 36% of patients in the MERCI Retriever studies and 48% of those treated with the Penumbra System.
Rates of symptomatic intracranial hemorrhage ranged from 0% to about 10% with both devices.
The team notes that, to date, neurothrombectomy devices have mostly been trialed only in patients who failed therapy with intravenous tissue plasminogen activator (tPA), presented too late for it, had contraindications to it, or had occlusions known to be resistant to tPA treatment.
Thus, it is not yet clear which patients could derive the most benefit from neurothrombectomy.
Pooja Khatri (University of Cincinnati, Ohio, USA) said that the "uncertainty about the effectiveness of neurothrombectomy is unsettling."
If effective, then its use is "distressingly low," she said, but conversely, if ineffective, its use is "wasteful and perhaps even harmful."
She stressed that clinicians should focus on conducting randomized trials. "It is premature to compare different devices until we first establish the clinical benefit of neurothrombectomy over thrombolysis," she said. "Until then, expansion of the use of neurothrombectomy is unjustified."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Eleanor McDermid