Diagnosis and therapy of subclinically infected prostheses.

We believe 5 to 7 percent of prosthetic devices are "subclinically" infected by Staphylococcus epidermidis. These infections are manifested by chronic pain, migration and late extrusion of the devices. To examine this problem, we cultured penile and mammary prostheses. For the experimental arm, we cultured painful penile and mammary prostheses that were being removed because of symptoms (pain). For patients in a control group, we cultured penile prostheses being replaced because of mechanical failure (no pain) and mammary tissue expanders that were temporarily installed. Actual parts of the device were cultured in Trypticase Soy Broth. There were 14 and 12 painful penile and mammary prostheses, 13 and ten, respectively, were cultured positive, for an infection rate of 88 percent. The primary organism identified was S. epidermidis. The nonpainful penile prostheses (zero of five and three of 22 mammary prostheses) grew S. epidermidis. The differences were highly significant (p < 0.001), suggesting that the painful prosthesis is infected. In an attempt to resolve the problem of the painful prosthesis, ten prosthesis were removed and exchanged for new devices. Patients received preoperative and postoperative antibiotics. All ten had positive cultures and nine of ten were successfully exchanged (no pain).