Analysis of flow changes in forearm arteries after raising the radial forearm flap: a prospective study using colour duplex imaging.

The purpose of this study is to assess the changes in flow patterns of forearm arteries produced by excision of the radial artery when harvesting the radial forearm flap, in order to clarify its vascular morbidity rationally. Eleven patients with elective surgery using the radial flap were included in this investigation. A prospective study was designed using colour duplex imaging for quantitative flow measurement in two stages: a few days before the operation, a first colour duplex scanning examination was done recording flow velocity and vessel section area from the radial, ulnar, posterior interosseous and anterior interosseous arteries around the wrist. Volumetric parameters and relative blood flow percentages were calculated and compared to those obtained from a second similar vascular investigation accomplished in the same limb 4-5 months after the operation. Statistical analysis was done using the Wilcoxon matched pairs test. After raising the radial forearm flap there was a trend for increased overall forearm flow (from 162 to 215 ml/min, P = 0.09 N.S.), the ulnar (P = 0.04), the posterior interosseous (P = 0.004) and the anterior interosseous (P = 0.003) arteries being responsible for this tendency. The anterior interosseous artery showed the greatest increase in blood (from 8.2 to 67.7 ml/min), reaching a relative flow percentage (33%) close to that of the radial artery before its excision (39%). Results of this study indicate that another 'major vascular axis' based on the anterior interosseous artery develops after sacrificing the radial artery and that global arterial inflow to the hand is not impaired.