Evaluation of acute traumatic changes of the coronary artery wall after robotically assisted endoscopic coronary...

There is concern that the technical limitations of robotic systems used in endoscopic coronary artery bypass grafting (CABG) may lead to increased trauma of the anastomotic site. To examine this issue, we compared the acute traumatic changes of the coronary artery wall caused by conventional manual suturing and robotically assisted suturing for anastomoses using the ZEUS telemanipulator (Computer Motion Inc., Goleta, CA) in a laboratory setting.

Coronary artery bypass grafting was performed on isolated porcine hearts. Fifteen anastomoses (with harvested porcine right coronary artery (RCA) segments) were carried out using the ZEUS microsurgical telemanipulator (group Z), while 15 further anastomoses were performed with a conventional manual technique (group M) using Gore-Tex CV-8 suture material. Specimens were taken from each anastomotic site and from native parts of the left anterior descending artery (LAD) (control group). Morphological changes of the cellular and fibrous components of the lamina intima and lamina media, and the shape and maximum diameter of the puncture mark, were examined by light microscopy (LM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Vascular endothelial damage and denudation were graded on a score from 1 to 5.

In each group, 14 specimens were evaluated. SEM findings showed a significantly higher degree of endothelial denudation in group Z and group M compared to the control group, while group Z was significantly more affected than group M. Likewise, the maximum diameter of the puncture mark was significantly larger in group Z than in group M. TEM and LM studies supported these results. In addition, LM revealed that in five specimens of group Z the shape of the stitch through the artery wall was not cylindrical, as in the other cases, but was asymmetrical and displayed a superficial furrow on the side of the vascular lumen.

The results indicate that there is an increased incidence of damage to the coronary artery wall caused by the microsurgical telemanipulator. Further studies are necessary to determine whether the differences between conventional and robotic-assisted suturing techniques will have an effect on the long-term outcome of coronary artery bypass grafting.