Background. The safe development of minimally invasive coronary artery bypa
ss operations might require alternatives to conventional suture-based anast
omotic techniques. In this setting, nonpenetrating stapling is an attractiv
e option because of its simplicity of use and potential for improved endoth
elial preservation.
Methods cmd Results. In the experimental part of this study, porcine intern
al mammary arteries were anastomosed to left anterior descending coronary a
rteries using either an 8-0 polypropylene running suture or nonpenetrating
microclips (7 anastomoses in each group). The endothelium-dependent relaxat
ions to bradykinin of the arterial rings bearing the anastomosis and of non
instrumented rings were compared in organ chamber experiments. There were n
o significant differences in maximal relaxations (mean +/- SEM) between the
microclipped and sutured anastomoses (81% +/- 7% versus 74% +/- 10%), whic
h were both significantly lower than those of control coronary rings (98% /- 2%, p = 0.001 versus the two anastomosed groups). Histologic examination
showed a comparable preservation of the coronary and graft endothelium wit
h both techniques. The clinical part of the study comprised 7 patients in w
hom the left internal mammary artery was conventionary sutured to the left
anterior descending whereas 13 saphenous vein grafts were anastomosed to th
eir target vessels by nonpenetrating staples. There were no clip-related co
mplications. An angiographic assessment of the venous grafts was performed
within 10 days postoperatively in all patients. One graft is presumably occ
luded. The 12 remaining conduits were patent with stapled anastomoses featu
ring a widely open "shark-mouth" configuration.
Conclusions. These preliminary data suggest that nonpenetrating stapling is
an easy-to-use technique that competes well with conventional suturing, at
least in terms of immediate results. Further studies are warranted to bett
er define its potential place within the armamentarium of minimally invasiv
e coronary artery bypass techniques. (C) 1998 by The Society of Thoracic Su
rgeons.