Determination of Optimal Fluoroscopic Angulations for Left Main Coronary Artery Ostial Interventions: 3-Dimensional Computed Tomography Validation

Figure 1. Optimal projection to visualize the LMCA ostium determined by fluoroscopic images of the wires. LAO = left anterior oblique; CRA = cranial.

Figure 2. Optimal projection to visualize the LMCA ostium estimated by FluoroCT: (a) the aortic annulus (yellow line) and LMCA plane (blue line) were determined; and (b) the optimal projection of the LMCA ostium was fixed when two S-curves consisting of an unlimited number of pairs of C-arm angulations which were tangential to the aortic annulus and the LMCA ostium crossed. LAO = left anterior oblique; RAO = right anterior oblique; CRA = cranial; CAU = caudal.

Figure 3. The blue reference line crossed the center of the cusp plane and the NCC-RCC commissure (bottom left corner). The NCC and RCC overlapped when viewed in the coronary plane. The angulation of NCC and RCC overlapping would be seen at the bottom of the coronary plane (right). NCC = noncoronary cusp; RCC = right coronary cusp. LAO = left anterior oblique; RAO = right anterior oblique; CRA = cranial; CAU = caudal.

Figure 4. Definitions of the angle between the LMCA ostium and the NCC-RCC commissure. ‘Dot A' was at the NCC-RCC commissure. ‘Dot O' was at the center of the cusp plane of the aortic valve. ‘Dot B' was at the opposite side of dot A on the cusp plane. ‘Dot C' was at the center of the LMCA ostium. The angle between the LMCA ostium and NCC-RCC commissure was ∠BOC. The LMCA ostium was considered to be facing the NCC-RCC commissure when ∠BOC was equal to 0°.

Figure 5. Comparison of the NCC and RCC overlapping between coordinates generated using each method on (a) horizontal and (b) vertical axes and comparison of the optimal projection to visualize the LMCA ostium between coordinates generated by each method on (c) horizontal and (d) vertical axes.

Figure 6. Comparison of the 3D deviation in the optimal projection to visualize the LMCA ostium between fluoroscopy and CT comparing patients in whom the LMCA ostium faced the NCC-RCC commissure (n = 32) vs. patients in whom the LMCA ostium did not face the NCC-RCC commissure (n = 13). LMCA = left main coronary artery; FNRC = face to the NCC-RCC commissure.

Figure 7. (a) Two 0.035-inch wires were advanced to the NCC and RCC using the anterior-posterior view; (b) the lowest points in the curve at the distal part of these two wires were superimposed at LAO18/CRA16; (c) LMCA angiography was performed at the angulation; (d) the stent was located at the angulation; (e) the image of LMCA after stent deployed; (f) LMCA ostial lesion was showed by intravascular ultrasound (OptiCrossTM HD; Boston Scientific) that was withdrawn at a pullback speed of one millimeter equal to 60 frames before stenting; (g, h) in the poststenting pullback, the LMCA ostium was at frame 1708 and the stent ostium was at frame 1814. So the stent protruded to the aorta for 1.77 mm ((1814–1708)/60); (i) the NCC and RCC overlapped at LAO12/CRA18 by FluoroCT; (j) the LMCA ostium faced to the NCC-RCC commissure in this patient (bottom left corner); (k) blue line was aortic valve plane and orange line was LMCA plane; (l) the two S-curves consisting of an unlimited number of pairs of C-arm angulations which were tangential to the aortic annulus and LMCA ostium crossed at LAO12/CRA21. CAU = caudal; CRA = cranial; LAO = left anterior oblique; RAO = right anterior oblique.

Figure 8. (a) Two 0.035-inch wires were advanced to the NCC and RCC using the RAO and CAU view; (b) the lowest points in the curve at the distal part of these two wires were superimposed at LAO 28/CRA 16; (c) the stent was located at the angulation; (d) the image of LMCA after stent deployed at RAO 5/CRA 31; (e) in the poststenting pullback with the speed of one millimeter equal to 60 frames, the LMCA ostium was at frame 595; (f) the stent ostium was at frame 665. So the stent protruded to the aorta for 1.17 mm ((665–595)/60). CAU = caudal; CRA = cranial; LAO = left anterior oblique; RAO = right anterior oblique.