Purpose: In men with spinal cord injury poor quality semen is seen when performing electroejaculation and penile vibratory stimulation. We determined whether sperm stasis within the seminal vesicles is a potential cause of this problem.
Materials and methods: Seminal vesicle aspiration was performed immediately before electroejaculation or penile vibratory stimulation in men with aspermia secondary to spinal cord injury. Sperm count and quality of seminal vesicle aspiration and subsequent ejaculation were compared with historical ejaculated counts, ultrasound findings and patient characteristics.
Results: Mean total number of right plus left seminal vesicle sperm plus or minus standard deviation was 511 +/- 960 x 10(6). Mean total number of sperm obtained by seminal vesicle plus electroejaculation or penile vibratory stimulation was 918 +/- 1,261 x 10(6). Average motility and viability of the seminal vesicle aspirated sperm were 1.3 and 3.2%, respectively. Average motility of the ejaculated sperm was 26.4% after seminal vesicle aspiration versus 16.3% in previous ejaculation induction procedures performed in the same patients. Seminal vesicle aspirated sperm represented 66% of the total number of sperm obtained during the session and was equal to 49% of the sperm obtained at previous electroejaculation or penile vibratory stimulation sessions. The period of abstinence correlated only with ejaculate count (simple regression p = 0.009). No other clinical characteristics had any effect on sperm count or quality.
Conclusions: Large numbers of poor quality sperm are present within the seminal vesicles of spinal cord injured men and these sperm comprise a large portion of the specimens collected by electroejaculation or penile vibratory stimulation. This phenomenon is independent of the period of abstinence, implicating disordered storage of sperm due to spinal cord injury rather than infrequent ejaculation. The large number of senescent sperm within the seminal vesicles appears to be a primary cause of poor sperm quality in spinal cord injured men.