Response to letter from Yoshino et al.: Vascular closure staples for experimental organ transplantation [1]

In our study we evaluated the surgical suitability of extramucosal titanium clips (vascular closure staples [VCS]) for biliary reconstruction in an animal model. Expertise in the use of VCS clips in reconstruction of the bile duct is rare and have been evaluated mostly in an animal model. Leppäniemi et al. (1) demonstrated a significant reduction of closure time in a supraduodenal choledochotomy porcine model. No significant changes were found in the inner diameter and smooth muscle surface of the bile duct.

The primary therapeutic use of VCS clips in humans is vascular anastomosis. In addition to the broad range of use in vascular surgery, VCS clips may also be applied in microvascular reconstruction. Cope et al. (2) reported the use of VCS clips in 153 cases of microvascular anastomosis (venous and arterial) in 87 free flaps. There were no postoperative anastomotic complications of bleeding, thrombosis, or need for revision. At the same time, the duration for completion of anastomosis was significantly reduced. Even in small-caliber anastomosis the use of VCS clips may be beneficial in humans. Zeebregts et al. (3) reported the use in aortic end-to-end anastomosis in Wistar rats. They compared clipped anastomosis and hand-sewn anastomosis in 12 and 6 rats, respectively. Both groups showed 100% patency rates. In follow-up, scanning electron microscopy revealed a milder inflammatory response at week 1 and more complete endothelial regeneration at weeks 4 and 8 postoperatively in the clipped group as compared with the suture group.

It is known from experimental studies that anastomotic time and warm ischemic time in transplant surgery can be shortened by the use of vascular closure staples. Yoshino and coworkers showed a remarkable reduction in warm ischemic time in several experimental organ transplantations using VCS clips for vessel reconstruction. In porcine intestinal, piglet liver, and feline renal transplantations they showed an approximately 50% reduction in warm ischemic time using medium and small clips. As for end-to-end anastomosis of the aorta and superior vena cava of the heart graft to the carotid artery and vein of the rat, no significant differences were found between the clip technique, hand suturing, and cuff methods. Although Yoshino et al. reported difficulties in establishing side-to-end anastomosis in vessels less than 2 mm, it was still possible to reduce warm ischemic time in anastomosis of these small-caliber vessels.

In our opinion, vascular closure staples are a beneficial tool in vascular and transplant surgery, in particular for timesaving reasons, and they may also be used for small-caliber anastomosis. The VCS technique should become an integral part of the operative spectrum of all vascular surgeons. However, there is no doubt that conventional suturing will continue to be the standard until further data are available. Also, there are conditions that favor manual suturing, such as long distance suturing and nonturnable anastomosis.

Matthias Birth

Uwe Markert

Markus Kleemann