50 patients with carpal tunnel syndrome (CTS) were randomized to receive open surgical carpal tunnel release with a subsequent longitudinal epineurotomy of the nerve or open carpal tunnel release without epineurotomy. Over 180 days post-surgery, nerve volume was found to be similar in both groups. The epineurotomy group had a slightly larger volume at 90 days than the control group, but this difference was not statistically significant. At 180 days, there was a small but significant difference in pain scores between the two groups, in favour of the control group. The results from this trial indicate that the addition of longitudinal epineurotonomy does not lead to any advantage over carpal tunnel release alone.