RESUMEN
<p><b>OBJECTIVE</b>To investigate the dynamic changes of the epididymal size 1 year after vasectomy.</p><p><b>METHODS</b>Fifty male volunteers received vasoligation. Before and at 1, 2, 3, 6, and 12 months after operation, we measured the size and detected the internal echoes of the epididymis using color Doppler ultrasonography.</p><p><b>RESULTS</b>The bilateral epididymides were both thickened post-operatively in all the 50 cases, with statistically significant differences between the baseline and the 1st month, the 1st and the 2nd month, the 2nd and the 3rd month, or the 3rd and the 6th month after surgery (all P < 0.01), but not between the 6th and the 12th month (P > 0.05).</p><p><b>CONCLUSION</b>Within 6 months after vasectomy, the bilateral epididymides manifested a progressive thickening, but basically restored their balance of secretion-absorption after 6 months.</p>