ABSTRACT
Thrombosis following microvascular anastomosis requires further surgical intervention,
involving anastomotic resection and reanastomosis or interpositional vein grafting.
This study was undertaken to investigate different methods of salvaging thrombosed
vessels, using a rat-vein model of error-induced thrombosis. Vessels were reconstructed
4 hr after the onset of thrombosis, using one of three methods: Group 1-removal of
the erroneously placed stitch; Group 2-anastomotic resection and reanastomosis; and
Group 3-resection and replacement with a vein graft. Adjuvant antithrombotic therapy
was simultaneously evaluated, assessing the influence of systemic Iloprost or heparin.
Patency rates at one day postoperatively were 0 percent, 12.5 percent and 37.5 percent
for Groups 1, 2, and 3, respectively. Following Iloprost infusion, these rates increased
to 25 percent, 25 percent, and 56.3 percent, respectively and, following heparin administration,
to 50 percent, 68.8 percent, and 81.8 percent, respectively. Significant increases
were found for vein grafting (Group 3), and for the heparin-treated subgroups using
all three methods. Effective levels of both Iloprost and heparin were confirmed by
increases noted in rat-tail bleeding times. Significant rates of recanalization by
three days following one-day occlusion were found in Groups 1 and 2. These results
support the application of vein-graft replacement for thrombosed veins, concurrently
with systemic heparinization. This study further confirms the high rate of recanalization
seen in thrombosed rat femoral veins.
