LONG-TERM MECHANICAL RELIABILITY OF AMS-700 SERIES INFLATABLE PENILE PROSTHESES - COMPARISON OF CX CXM AND ULTREX CYLINDERS/

Purpose: Recently, we have noted an increasing incidence of revisions being performed in patients implanted with the length and girth expand ing AMS 700 Ultrex inflatable penile prosthesis. This observation pro mpted us to compare the long-term mechanical reliability of the AMS Ul trex inflatable penile prosthesis versus the girth-expanding AMS 700 C X or CXM* inflatable penile prosthesis in men with organic erectile d ysfunction. Materials and Methods: Using chart review, mailed question naires and telephone interviews, rye obtained accurate followup on 111 of 142 (78.2%) patients with CX/CXM implanted between June 1986 and S eptember 1995, and on 152 of 179 (84.9%) patients implanted with Ultre x between October 1989 and September 1995. The CX/CXM and Ultrex group s were compared with regard to 3 end points: 1) mechanical failure cau sed by any malfunctioning component, 2) device failure caused by any c ylinder complication and 3) cylinder aneurysms/leaks. Results: Followu p ranged from 1.0 to 112.0 months for the CX/CXM group (mean 47.2 mont hs), and 0.7 to 71.5 months for the Ultrex group (mean 34.4 months). C X/CXM versus Ultrex group comparison demonstrated 10 CX/CXM mechanical failures (9.0%) versus 26 Ultrex failures (17.1%), p = 0.001; 5 CX/CX M cylinder complications (4.5%) versus 13 Ultrex cylinder complication s (8.6%), p = 0.0292; and 3 CX/CXM cylinder aneurysms/leaks (2.7%) ver sus 9 in the Ultrex group (5.9%), p = 0.0162. Kaplan-Meier estimates d emonstrated significantly decreased mechanical survival in all 3 categ ories for Ultrex inflatable penile prosthesis versus CX/CXM inflatable penile prosthesis. Conclusions: Although Ultrex cylinders provide len gth and girth expansion, Ultrex cylinders exhibit an increased mechani cal failure rate at shorter followup compared with CX/CXM cylinders. T his increased propensity for Ultrex cylinder problems should be closel y monitored.