Three-Dimensional Endoscopy: Impact on Learning Curve of Minimally Invasive Mitral Valve Surgery

All articles of this category Objective: Minimally invasive mitral valve surgery (MIMVS) has become the routine approach at many centers. Use of three-dimensional (3D) endoscopy is the latest step of continuous technical refinement. We analyzed the impact of 3D endoscopy regarding learning curve effects and clinical outcome of MIMVS. Methods: From 2010 to 2016, a total of 362 patients underwent MIMVS. Of these patients, 243 were treated using standard 2D endoscopy (group 1) and 119 using 3D endoscopy (group 2). These procedures were performed by 6 surgeons with similar individual caseloads but at different stages of training. Individual and cumulative learning curves regarding operation times and perioperative complications were assessed for 3D-endoscopy-guided procedures. Operation times, complications and functional results of both groups were comparatively assessed. Results: Age was 55.3 ± 12.4 years (group 1) versus 57.7 ± 10.6 years (group 2; p = 0.07), 31.3% versus 31.1% ( p = 0.91) were female, respectively. Bileaflet prolapse was seen in 21.4% (group 1) versus 14.3% (group 2; p = 0.11). Complexity and number of repair techniques performed were not significantly different for both groups. We did not observe an obvious overall or individual learning curve regarding operation times for 3D-endoscopy-guided procedures. Surgeons in earlier training stages did not show significantly longer operation times than experienced surgeons. Individual and cumulative learning curves regarding perioperative complications did also show no obvious learning effect. Operation times were 263.34 ± 62.48 minutes versus 262.59 ± 52.13 minutes in groups 1 and 2, respectively ( p = 0.91). Re-exploration for bleeding was performed in 1.6 versus 1.7% ( p = 0.98), conversion to sternotomy was performed in 1.6 versus 0.8% ( p = 0.49). Impaired wound-healing was not seen in group 2, but in 1.6% of group 1 ( p < 0.01). Discharge echocardiography showed excellent results in both groups with 1.6 versus 0.8% >mild recurrent regurgitation in groups 1 and 2 respectively ( p = 0.49). Conclusion: In our early experience of 3D-endoscopic MIMVS we could not identify typical learning curve patterns. Operation times were stable from the beginning for each surgeon. Compared with the established group 1-procedure we found similar complication rates, functional results and operation times. Use of 3D endoscopy may facilitate training for MIMVS by increasing orientation and depth perception.