Immediate Nicoladoni procedure in the rhesus monkey, or hallux-to-hand transplantation, utilising microminiature vascular anastomoses

RECONSTRUCTION of a missing thumb by pollicisation of a finger (Littler, 1953) produces the most satisfactory functional result, even though this entails transposing an adjacent digit on an already compromised hand. Local tissue may be preserved by the multiple stage construction and transfer of distant tubes and pedicles containing bone grafts (Reid, 196o). McGregor has overcome many of the disadvantages of this procedure with a composite bone skin flap incorporating a neurovascular tactile island at the time of transfer (McGregor and Simonetta, 1964). The transplantation of the toe to the hand first described by Nicoladoni in 1897 has held a somewhat controversial place in hand reconstruction. This interesting history has been reviewed recently by Davis (I964), who has improved and modified the technique. The objectives of this experiment were to transplant immediately the hallux of a Rhesus monkey's foot to the thumb position, re-establishing circulation by the F~G. ~ primary anastomoses of small critical blood Right hand (above) and foot (below) of a Rhesus vessels. monkey. The thumb is small, the hallux is large and strong. Mater ia l . -The Rhesus monkey was used as the experimental animal. Being arboreal the animal uses its fingers as hooks to swing from limb to limb. The thumb consequently is small and poorly developed (Fig. I). The hallux, however, is large and capable of strong opposition, paralleling the human thumb from a functional standpoint (Bunnell and Boyes, 1965) (Fig. 2 D, ~). The principal arterial supply to the dorsum of the animal's foot comes via the superficial dorsalis pedis to the hallux and first web space and the deep dorsalis pedis to the remainder of the dorsum. These are terminal branches of the saphenous artery not present in man. Blood is drained from the dorsum of the foot through the medial malleolar and lateral malleolar veins into the posterior saphenous system, since the anterior great saphenous system is absent in the Rhesus monkey (Lopel et al., I961). These vessels on the foot's dorsum in an 8 to 12 lb. Rhesus monkey measure from 08 to I 3 mm. in external diameter.