Nowadays, microvascular reconstructions are performed with high success rate even in small children. The combination of general anaesthesia and axillary plexus block was used in this prospective study in order to achieve optimal surgical conditions in these challenging operations. Fifteen children under eight years of age (1-8 years) were anaesthetised with a standardised anaesthesia method using a combination of general anaesthesia and axillary plexus block for microvascular toe-to-hand transfer. The duration of anaesthesia varied between 7.5-14.5 hours (mean 11 h). The difference in peripheral skin temperature was used to indicate the difference in peripheral circulation. Due to plexus block, the mean skin temperature in the operated hand was 1.4 degrees C higher than in the opposite extremity at the end of the operation. In the early postoperative phase the temperature difference increased to 4.8 degrees C (P < 0.01) due to vasoconstriction in the control hand. The mean temperature in the transplant was 33.3 +/- 2.4 degrees C at the end of the operation. Primary microvascular results were good in all but two children who needed reoperations. All of the transfers survived. The mean central temperature increased progressively during the operation from 36.2 degrees C to 37.6 degrees C. One 1-year-old child developed a moderate hyperthermia of 39.1 degrees C. According to this study axillary plexus block can be combined with general anaesthesia in prolonged microvascular operations. When the effect of general anaesthesia ceased, the plexus block effectively increased peripheral circulation in the operated hand.