The effects of urinary function and erectile function on the use of mecobalamin after nerve sparing radical prostatectomy

(Purpose) Mecobalamin has been reported to be useful for peripheral nerve disorder. There have been no previous reports of the effects of mecobalamin on urinary and sexual function after nerve sparing radical prostatectomy. We examined the effects of the use of mecobalamin on urinary and erectile functions after nerve sparing radical prostatectomy. (Materials and methods) A total of 54 patients with localized prostatic cancer were prospectively randomized into 2 groups. The 27 patients in group A were treated with nerve sparing prostatectomy and mecobalamin 1,500 μg/day for 6 months. The 27 patients in group B were treated with nerve sparing prostatectomy alone. Urinary function (URF), urinary bother (URB), sexual function (SXF) and sexual bother (SXB) were evaluated using the University of California at Los Angeles Prostate Cancer Index (UCLA-PCI) before surgery, and 3, 6 and 12 months after surgery. (Results) There were no significant differences in URF, URB, SXF or SXB between the two groups at any postoperative period. At 3 months after surgery, however, group A tended to have a better URF than group B (85.7 ±4.7 (mean ± standard error) vs. 66.9 ± 10.2) and URB (85.7 ±7.4 vs. 63.9 ± 11.8) (p = 0.121, p = 0.168). At 12 months after surgery, both groups showed similar URF (86.4 ± 7.4 vs. 81.8 ± 4.2) and URB (86.5 ± 8.3 vs. 84.5 ± 4.7). Although the two groups had similar recovery phase of SXF, group A tended to report better SXB throughout the postoperative period. (Conclusion) This study did not demonstrate any significant effect of the use of mecobalamin on the recovery of urinary or sexual function after nerve sparing prostatectomy, although an early recovery effect on urinary function was suggested. A randomized controlled study with a larger population is warranted to fully elucidate the role of mecobalamin in the improvement of functional outcome after radical prostatectomy.