NEW YORK (Reuters Health) - Swollen veins in the scrotum, known as varicoceles, are a common cause of infertility in men -- now new research suggests that the problem can be effectively treated with a minimally invasive procedure called retrograde venous embolization.

The procedure, which is done via a tiny catheter, works by blocking excessive blood flow into the veins, allowing them to shrink back to normal size.

The findings, which appear in the journal Radiology, indicates that retrograde venous embolization improves semen quality and results in sired pregnancies in roughly one third of partners.The study, by Dr. Sebastian Flacke, from the University of Bonn Medical School in Germany, and colleagues, involved 223 infertile men with 228 varicoceles who underwent retrograde venous embolization.

Overall, 226 varicoceles were successfully treated. Clinical and ultrasound testing revealed that the varicocele had fully resolved in 206 patients (92.4 percent).

Varicocele embolization was associated with significant improvements in both sperm count and motility. Still, the average values were still considered abnormal based on World Health Organization guidelines.

Sperm movement was the only significant pre-treatment predictor of pregnancy, the authors found. Other potential predictors, such as varicocele severity, hormone levels, ultrasound findings, and other semen parameters did not.

The fertility benefits seen with retrograde venous embolization are "similar to those reported after surgical repair," the authors conclude. This treatment could be a "useful adjunct to in vitro fertilization therapy."