Penumbra stroke system

The Penumbra stroke system (Penumbra Inc., San Leandro, CA) includes two different revascularization options (1) thrombus debulking and aspiration may be achieved by a reperfusion catheter that aspirates the clot while a separator device fragments it, and (2) direct thrombus extraction may be performed by a ring retriever while a balloon guide catheter is used to temporarily arrest flow. This system has been tested in a pilot trial in Europe. Twenty patients (mean NIHSS 21) with a total of 21 vessel occlusions (7 ICA, 5 MCA, and 9 Basilar) were treated up to 8 hours after symptom onset. Recanalization prior to lA lysis was achieved in all cases (48% TIMI 2 52% TIMI 3). Seven patients were also treated with lA UK or rt-PA. Good outcome at 30 days (defined as mRS < 2 or NIHSS 4-point improvement) was demonstrated in 42%. The mortality rate was 45%, but there were no device-related deaths. There was one asymptomatic SAH and three symptomatic ICHs. A prospective, single-arm, multicenter trial is being conducted in the United States and Europe currently. 

Bose A, Jansen O. Clinical safety and performance of the penumbra stroke system a novel device for the treatment of acute stroke due to large vessel occlusive disease. European Stroke Conference Brussels, Belgium May 2006. 

The MERCl Retriever and Penumbra systems have been approved by the FDA to remove blood clots from the brain in patients experiencing an ischemic stroke. The remaining drugs and devices constitute off-label and/or investigational (precUnical or clinical) usage... 

Bose A, Henkes H, Alfke K et al. The Penumbra System a mechanical device for the treatment of acute stroke due to thromboembolism. AJNR Am J Neuroradiol. 2008 29 1409-1413... 

As mentioned earlier, survival of ischemic penumbra is highly dependent on the efficiency of collateral vasculature to provide adequate CBF in the periphery of the ischemic territory. The viability of the penumbra depends on the degree and the duration of ischemia. In animal stroke models the reduction of CBF in the periphery of the ischemic territory is down to about 20% (Jones et al., 1981). Similar levels of diminished CBF are observed in humans (Bandera et al., 2006). In a healthy brain, CBF is maintained between 60 and 150 mmHg by vasoconstriction or vasodilatation in response to changes of perfusion pressure. However, during ischemia this autoregulation is lost, which makes the penumbra highly dependent on systemic blood pressures. 

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