EPAR Therapy System for Treatment of Acute Stroke: Safety Study Results
Background. Laser thrombolysis offers the potential for rapid clot removal. This multicenter study assessed the safety of the Endovascular Photo Acoustic Recanalization (EPAR) laser system in the intra-arterial treatment of acute stroke. Methods. Patients had a NIHSS score of 4 or more and angiographically demonstrated occlusion (TIMI 0–1) of the internal carotid (ICA), anterior cerebral (ACA), middle cerebral (MCA), posterior cerebral (PCA), basilar or vertebral artery. Patients were treated within 6 hrs of stroke in the anterior circulation and within 24 hrs in the posterior circulation. Cerebral blood flow before and after the EPAR procedure was assessed angiographically. Clinical outcome was measured at baseline, 7 days and at 30 days using the Modified Rankin (MR) and NIHSS. Both power and energy were adjusted upwards during the trial to establish the limits of safety. Results. Twenty-seven patients were enrolled in the study and 26 patients were treated with the laser. The baseline median NIHSS score was 21 (range 12–40) and the mean age was 65 (range 39–78). The vessels treated included four supraclinoid ICAs, one ACA, 16 MCAs, two PCAs, seven basilars and one vertebral artery. Twelve patients had died by 30 days (46%). Five patients developed a symptomatic ICH (19%), four of whom also received lytics. No complications occurred during active lasing. Three vessel perforations occurred, one prior to introduction of the EPAR device and two during manipulation of the wire and device prior to lasing. None of these extravasations was associated with any untoward clinical effects. Of 31 vessel segments treated, fifteen (48%) improved by at least one grade of TIMI flow after EPAR laser treatment. In those patients who survived, the median NIHSS score was 17 (range 2–38) at 7 days (n=16) and 15 (range 1–37) at 30 days (n=12). The mean MR was 4.3 (range 2–5) and 3.5 (range 0–5) at 7 and 30 days, respectively. Conclusions. The EPAR laser system has shown acceptable safety, demonstrating no serious complications during active lasing. The high mortality in this population is comparable to that in other groups with similarly severe presenting strokes. Further clinical studies are planned.