This study examined the possibility of an adaptive reaction of anastomosed arteries under tension during a distraction lengthening procedure in the tibiae of rabbits. After an osteotomy at the mid tibia, the posterior tibial arteries were transected and anastomosed. Using a pair of small external fixators, the tibiae were distracted at a rate of 0.5mm/day (groups I–IV rabbits). Three weeks after 25% lengthening, the patency and histology of the arteries were examined. Angiography revealed that all of the anastomosed arteries were patent, and intimal hyperplasia was a constant finding. The mean thickness of the intima of the lengthened segment in group I was 60.4μm, which is 5.0, 3.4 and 2.1 times higher that of the controls in groups IV (un-manipulated arteries, 12.2μm), III (unlengthened but anastomosed arteries, 17.8μm) and II (lengthened but untouched arteries, 28.7μm), respectively. These results show that an anastomosed artery can maintain its patency at a certain level and speed of distraction lengthening. Therefore, it is possible that distraction lengthening and vascular anastomoses can be performed simultaneously provided there is careful monitoring of the circulation.