development of a new catheter prototype for laser thrombolysis under guidance of optical coherence tomography (oct): validation of feasibility and efficacy in a preclinical model

In this feasibility study, a novel catheter prototype for laser thrombolysis under the guidance of optical coherence tomography (oct) was designed and evaluated in a preclinical model. human arteries and veins were integrated into a physiological flow model and occluded with thrombi made from the chandler loop. there were four experimental groups: placebo, 20 mg alteplase, laser, 20 mg alteplase + laser. the extent of thrombolysis was analyzed by weighing, oct imaging and relative thrombus size. in the alteplase group, thrombus size decreased to 0.250 ± 0.036 g (p < 0.0001) and 14.495 ± 0.526 mm2 (p < 0.0001) at 60 min. the relative thrombus size decreased to 73.6 ± 4.1% at 60 min (p < 0.0001). in the laser group, thrombus size decreased significantly to 0.145 ± 0.028 g (p < 0.0001) and 11.559 ± 1.034 mm2 (p < 0.0001). in the alteplase + laser group, thrombus size decreased significantly (0.051 ± 0.026 g; p < 0.0001; 9.622 ± 0.582 mm2; p < 0.0001; 47.4 ± 6.1%; p < 0.0001) in contrast to sole alteplase and laser application. the reproducibility and accuracy of the oct imaging was high (sd <10%). histological examination showed no relevant destruction of the vascular layers after laser ablation (arteries: 745.8 ± 5.5 μm; p = 0.69; veins: 448.3 ± 4.5 μm; p = 0.27). thus, laser ablation and oct imaging are feasible with the novel catheter and thrombolysis combining alteplase with laser irradiation appears highly efficient.