Evaluation of the long-term results of vascular anastomosis using polyurethane adhesive and shape-memory stent in the rat carotid artery model.INTRODUCTION
 In free flaps, 5%-10% of complications are related to failure of sutured vascular anastomoses.  Adhesive-based microvascular anastomoses are potential alternatives but are associated with failure rates of 70% in research studies.  VIVO is a new adhesive with slow biodegradation within 6 months that has shown a 100% patency rate in research studies over 2 h observation time but long-term patency has not been evaluated.  The authors hypothesize that VIVO will enable a reliable microvascular procedure comparable to sutured anastomoses over a 28-day period.


 The right common carotid artery of 60 male Sprague Dawley rats, ~450 g, were used for microvascular end-to-end anastomosis.  VIVO was applied with reduced sutures with a temporary catheter in one group and in the other with a custom-shaped memory stent.  Anastomoses with eight interrupted sutures served as control.  Anastomosis time and bleeding were recorded for each procedure.  Postmortem toluidine staining was used for semi-quantitative analysis of stenosis, thrombosis, necrosis, and aneurysm formation by histologic evaluation.


 No occlusion was detected 20 min and 1 day postoperative, and after 28 days of observation in all anastomoses.  The anastomosis time of the VIVO with catheter group was about 32% significantly faster than the VIVO with stent group.  In the VIVO group with stent, the bleeding time was ~80% shorter than in the control group with 2.1 ± 0.3 and VIVO with catheter 2.0 ± 0.5 (p ≤ .001 each).  Minor and nonsignificant stent-associated thrombus formation and stent-typical intraluminal stenosis were detected exclusively in the VIVO with stent group.


 CONCLUSION
 VIVO with catheter was found to be advantageous.
C
VIVO is a new adhesive with slow biodegradation within 6 months that has shown a 100% patency rate in research studies over 2 h observation time but long-term patency has not been evaluated.  The authors hypothesize that VIVO will enable a reliable microvascular procedure comparable to sutured anastomoses over a 28-day period.


 VIVO was applied with reduced sutures with a temporary catheter in one group and in the other with a custom-shaped memory stent.  The anastomosis time of the VIVO with catheter group was about 32% significantly faster than the VIVO with stent group.  In the VIVO group with stent, the bleeding time was ~80% shorter than in the control group with 2.1 ± 0.3 and VIVO with catheter 2.0 ± 0.5 (p ≤ .001 each).  Minor and nonsignificant stent-associated thrombus formation and stent-typical intraluminal stenosis were detected exclusively in the VIVO with stent group.


 Within the limitations of a rat study, the use of VIVO in anastomosis showed promising results.  VIVO with catheter was found to be advantageous.
VIVO