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Diagnosis and therapy of subclinically infected prostheses
C L Parsons1, P C Stein, M K Dobke
1Division of Urology, University of California San Diego Medical Center.
Abstract:
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).
Insights
Subclinical Staphylococcus epidermidis infections are common in prosthetic devices, causing pain and device failure. This study found an 88% infection rate in painful prostheses, significantly higher than in non-painful ones.
Area of Science:
- Medical Microbiology
- Biomedical Engineering
- Infectious Diseases
Background:
- Prosthetic devices can harbor subclinical infections, primarily by Staphylococcus epidermidis.
- These infections are associated with chronic pain, device migration, and extrusion.
Purpose of the Study:
- To investigate the prevalence of Staphylococcus epidermidis infections in symptomatic (painful) versus asymptomatic prosthetic devices.
- To determine the efficacy of device exchange and antibiotic treatment for resolving painful prosthetic infections.
Main Methods:
- Cultures were performed on explanted penile and mammary prostheses from patients experiencing pain (experimental group) and those with mechanical failure (control group).
- Tissue expanders were used as additional controls.
- Microbiological cultures were conducted using Trypticase Soy Broth.
Main Results:
- An 88% infection rate with Staphylococcus epidermidis was observed in painful penile and mammary prostheses.
- Infection rates were significantly lower in non-painful penile and mammary prostheses (p < 0.001).
- Following device exchange and antibiotic treatment, 90% of patients experienced pain relief.
Conclusions:
- Pain in prosthetic devices is a strong indicator of Staphylococcus epidermidis infection.
- Surgical revision with new prosthetic devices and antibiotic therapy can successfully resolve painful prosthetic infections.