Comparative revision rates of inflatable penile prostheses using woven Dacron® fabric cylinders

Purpose: American Medical Systems (AMS) CX and LGX penile prostheses use woven Dacron® fabric to produce girth, and length and girth expansion, respectively. Cylinder expansion, while desirable, can result in wear of the material which, over time, may lead to device failure. Therefore, we compared girth and length expanding vs girth expanding cylinder survival rates. In addition, we determined the impact of parylene coating on penile prosthesis revision performed for mechanical reasons.

Materials and methods: All patient information forms from AMS 700™ CX and LGX/Ultrex penile prosthesis implantation performed in the United States from January 1997 through August 2008 were retrospectively analyzed (55,013). Device failure was defined as time to first revision. Survival rates of the 2 groups were analyzed and compared, and survival curves were generated.

Results: AMS 700 Ultrex/LGX parylene and CX parylene devices demonstrated equivalent estimated survival rates (88.7% vs 89.5%, respectively, log rank p=0.6811). The parylene coated CX and Ultrex/LGX devices outperformed the nonparylene coated devices on survival analysis.

Conclusions: This analysis demonstrated no significant difference in 7-year survival between current generation girth expanding (700 CX) and length and girth expanding (700 LGX/Ultrex) prostheses. This analysis also demonstrated that the parylene coating of the cylinder wall contact surfaces significantly reduced the revision rate of the 700 CX and 700 LGX/Ultrex inflatable penile prostheses.