To contribute to the literature about the anatomy of the dorsal ulnar artery and to clarify the anastomosis pattern between the descending branch of this artery and the vascular network of the hand. The distally pedicled dorsoulnar forearm flap can be a useful surgical flap for repairing hand and wrist defects. The vascular pedicle of this flap is the dorsal cutaneous branch of the ulnar artery (the dorsal ulnar artery). However, there is confusion about the anatomy of the vascular pedicle of this flap, since different findings have been reported in various anatomical studies. Materials and methods: The upper extremities of 5 cadavers were studied. The ulnar artery and its dorsal cutaneous branch were dissected, the entire arborizations of the dorsal ulnar artery were revealed, and measurements of the length and diameter of the dorsal ulnar artery were performed. Results: The dorsal ulnar artery was divided into ascending and descending branches. The descending branch was divided into 2 terminal branches after passing beyond the pisiform bone, and 1 of the terminal branches turned to the radial side at an angle of about 90° and anastomosed with the deep branch of the ulnar artery. Conclusion: The descending branch of the dorsal ulnar artery can be dissected as a flap pedicle up to the point at which the artery divides into its 2 terminal branches. This is the pivot point of the flap, and surgical dissection should be discontinued at this point.

To contribute to the literature about the anatomy of the dorsal ulnar artery and to clarify the anastomosis pattern between the descending branch of this artery and the vascular network of the hand. The distally pedicled dorsoulnar forearm flap can be a useful surgical flap for repairing hand and wrist defects. The vascular pedicle of this flap is the dorsal cutaneous branch of the ulnar artery (the dorsal ulnar artery). However, there is confusion about the anatomy of the vascular pedicle of this flap, since different findings have been reported in various anatomical studies. Materials and methods: The upper extremities of 5 cadavers were studied. The ulnar artery and its dorsal cutaneous branch were dissected, the entire arborizations of the dorsal ulnar artery were revealed, and measurements of the length and diameter of the dorsal ulnar artery were performed. Results: The dorsal ulnar artery was divided into ascending and descending branches. The descending branch was divided into 2 terminal branches after passing beyond the pisiform bone, and 1 of the terminal branches turned to the radial side at an angle of about 90° and anastomosed with the deep branch of the ulnar artery. Conclusion: The descending branch of the dorsal ulnar artery can be dissected as a flap pedicle up to the point at which the artery divides into its 2 terminal branches. This is the pivot point of the flap, and surgical dissection should be discontinued at this point.