Penumbra system: a novel mechanical thrombectomy device for large-vessel occlusions in acute stroke

Abstract

Background and purpose: Large IC artery occlusion is often resistant to recanalization. We present our initial experience with the PS.

Materials and methods: Presenting with a severe acute ischemic stroke, the first 27 consecutive patients were considered for thromboaspiration therapy and retrospective data base analysis. All patients received standard thrombectomy treatment as monotherapy or in combination with thrombolysis or IC stent placement. The primary end point was revascularization of the target vessel to grade 2 or 3 on the TICI scale. Secondary end points were improvement of >4 points on the NIHSS score at discharge and favorable outcome, and improvement in overall mortality at 3 months and in sICH- and procedure-related adverse events.

Results: At baseline, the mean age was 66 +/- 14 years and the mean NIHSS score was 14 +/- 7. The anterior circulation was affected in 23 patients, and there were 4 basilar artery occlusions. Intracranial stent placement was performed in 4 patients. A recanalization to TICI 2 or 3 was achieved in 25 patients (93%). None of the patients developed sICH. At hospital discharge, 15 patients (56%) had an NIHSS improvement of >4 and 13 patients (48%) had an mRS score of <2 at 3 months. There was a significant correlation between complete vessel recanalization and favorable outcome. The all-cause mortality at 3 months was 11%.

Conclusions: The PS showed a high potential for recanalization of acute thromboembolic occlusions of the large cerebral arteries. Complete recanalization was strongly correlated with good clinical outcome.

Fig 1.

Diagnostic illustration of a patient with acute stroke before treatment with the PS. A and B, Axial unenhanced CT scan (A) and CT perfusion cerebral blood flow map (B) obtained 2.5 hours after symptom onset demonstrate only subtle changes in the brain but a significant perfusion deficit in the right MCA territory. C and D, Selective right ICA injection angiogram, posteroanterior (C) and lateral (D) views, shows complete thromboembolic occlusion (arrows) of the ICA at the level of the origin of the anterior choroidal artery, which is still filling.

Fig 2.

Angiographic illustration of the right ICA after complete revascularization with the PS in the same patient as shown in Fig 1. Posteroanterior (A) and lateral views (B). C and D, Axial unenhanced follow-up CT images obtained 24 hours after treatment demonstrate only small putaminal and corona radiata ischemic lesions on the right. The patient had a complete recovery.