The role of adjunctive video angioscopy was evaluated in 43 patients with symptomatic peripheral vascular disease undergoing percutaneous atherectomy with the Simpson atherocath. There were 57 target lesions (superficial femoral, n = 46; popliteal, n = 11) of which 33 were stenotic (86 +/- 11%) and 24 were total occlusions of 0.5 to 10.6 cm in length, determined by angiography. Intraluminal inspection, with angioscopes of 0.85 to 1.5 mm in outer diameter housed within a guide catheter, could be performed in 55 of 57 lesions (96%) before atherectomy and in 39 of these 55 (71%) after atherectomy. Failure to obtain an adequate image was usually due to insufficient irrigation, especially in recanalized vessels. In 13 of 23 successfully recanalized arteries (54%) the occlusion could be crossed by the angioscope itself, whereas in 10 cases (42%) a guidewire or a sheath introducer was necessary. Angioscopic passage revealed that often long total occlusions, determined by angiography, consisted of greater than or equal to 1 discrete occlusion with interposed patent thrombus-free vascular segments. After atherectomy, in 15 instances with an acceptable angiographic result, angioscopy was helpful in identifying residual plaques and flaps which then selectively underwent atherectomy. In conclusion, angioscopy proved to be a useful adjunct to angiography in optimizing vascular recanalization with percutaneous atherectomy.