Evaluation of a Multiple Injection AXB by Clinical Assessment and MRI

Trygve Kjelstrup, MD, has developed an axillary brachial plexus block technique that combines the insertion of a catheter with a double transarterial injection technique. In clinical practice this triple-deposit method showed promising block effect on the nerves of the brachial plexus that innervate the upper extremity. In the present thesis the triple-deposit axillary block method was evaluated by clinical tests and with MRI. Particularly, we investigated whether differences in block success could be explained by differences in local anaesthetic distribution as observed by MRI. This thesis demonstrated that the triple-deposit method has a higher block success and shorter onset time compared with the single- or double-deposit method. These findings could be explained by analysis of the MRI distribution patterns. MRI showed a wide variability as to where the musculocutaneous nerve leaves the axillary sheath. With the triple-deposit method the nerve can be successfully blocked. We conclude that an axillary plexus block performed with the triple-deposit technique is preferable as compared to the single- and double-deposit method.