Collateral arterial pathways in the forearm.

We studied the forearm vessels and the palmar carpal arch in 41 fresh cadaver upper limbs injected with colored latex solutions. In one case, we found a complete occlusion of the radial artery. Collateralization was evident through the anterior interosseous artery, its palmar branch and the radial part of the palmar carpal arch. The diameters of these vessels were significantly enlarged. The dissections of the remaining 40 arms demonstrated that these vessels offer a possible collateralization pathway via the anterior interosseous artery. One hypothesis for the formation of such collateralization might be a dominant blood flow of the radial artery to the hand. Therefore, it seems sensible to preserve the communication between the anterior interosseous and the radial arteries through the palmar carpal arch, raising the radial artery for surgery.