MR imaging-based port placement planning for totally endoscopic coronary artery bypass grafting

An easy applicable method for pre-operative port position planning for totally endoscopic coronary artery bypass (TECAB) grafting based on magnetic resonance (MR) coronary angiography and image post-processing is introduced and analyzed. For this, combined left main (LM) and left anterior descending (LAD) coronary arteries of 21 subjects (14 patients, 7 healthy volunteers with similar habitus) were investigated in MR by means of transversally orientated, three-dimensional (3D), fat-saturated, breath-hold true fast imaging with steady state precession sequences with real-time navigator-based slice following. For the healthy volunteers, the vertical dimension of the total 3D slab was enlarged to enable TECAB planning. Optimal endoscopic port positions were determined via image analysis and geometric methods. 13.8+/-2.1 cm mean continuously visible length of combined LM and LAD coronary arteries (no statistical difference between patients and healthy volunteers) allowed visualizing typical regions for suturing of the anastomosis in all 21 cases. The mean horizontal distance of the optimal endoscopic port position from the center of the sternum was 7.0+/-1.3 cm. In conclusion, MR imaging-based port position planning is feasible. Variability in the determined port positions indicates the necessity of adaptation of port positioning even for subjects with similar habitus.