"Rotation Overlap Method" for 3D Wiring in Chronic Total Occlusion

We describe the "rotation overlap method" for 3-dimensional (3D) wiring without orthogonal projections. This method ultilizes "parallax" to resolve wire shaft (WS) and target (TG) relationships according to the 'rotation overlap rule'. Rotate the fluoroscopic view toward the WS: if the WS-TG are seen closer, the WS becomes anterior to the TG (vice versa [away from WS = posterior]). This rule applies to any fluoroscopic rotation under 180°, regardless of axial or oblique to vessel. The "WS-TG closer" criterion replaces orthogonal projections to constrain the WS-TG spatial relationship. The steps for 3D wiring are as follows: For 2 fluoroscopic projections, the view with WS-TG closer is the "closer view," and the other is the "far view". 1) Resolve WS-TG anterior/posterior relationship in the "closer view" based on whether fluoroscopy is rotated toward/away from the WS in the "far view" to reach the "closer view." 2) Optimize the "closer view" for WS-TG overlap. 3) In the optimized "closer view," rotating the wire in the correct direction until the wire tip (WT) is central will precisely direct the WT toward the TG. Four scenarios (WS anterior/posterior × WT right/left) determine the correct wire rotation (clockwise or counter-clockwise).