Related Experiment Videos
The use of biodegradable amikacin microspheres to prevent vascular graft infection
A L Ney1, J A Granja, P A Schuster
1Department of Surgery, Hennepin County Medical Center, Minneapolis, Minnesota.
Abstract:
The following study was performed to determine if an antibiotic impregnated in a biodegradable polymer can prevent infection and eradicate inoculum bacteria from contaminated polytetrafluoroethylene vascular grafts. Poly(glycolide-co-dl-lactide) amikacin microspheres (PAM) measuring 50-100 microns were designed to deliver 100 mg (PAM 100) or 300 mg (PAM 300) amikacin per unit dose. Twenty mongrel dogs had a short segment of infrarenal aorta replaced with a graft that had been bathed in a 2 cc solution of Escherichia coli and Staphylococcus aureus (3 x 10(8) CFU/ml). Dogs were divided into three groups: Controls had contaminated grafts placed and received no therapy; PAM 100 and PAM 300 were used, respectively, to cover the grafts in the other two groups. Animals were sacrificed 14 days postoperatively at which time grafts were examined and cultured. Among controls, 7/8 had clinical graft infections and all had positive cultures for S. aureus (8/8) or E. coli (5/8). None of the treated animals had clinical graft infections (P < 0.001). Positive cultures were obtained for S. aureus in 2/8 (P < or = 0.007) and E. coli in 0/8 (P < or = 0.03) PAM 100 dogs and for S. aureus in 0/8 (P < or = 0.0002) and E. coli in 0/8 (P < or = 0.03) PAM 300 dogs. Two PAM 100 and four PAM 300 dogs had rare growth of contaminant bacteria (NS). In conclusion, PAM can prevent clinical graft infection and completely eradicate a standardized bacterial inoculum.
Insights
Biodegradable polymer microspheres loaded with amikacin antibiotic (PAM) effectively prevent and eradicate bacterial infections in contaminated vascular grafts. This study shows PAM significantly reduces clinical graft infections and bacterial presence in polytetrafluoroethylene grafts.
Area of Science:
- Biomaterials Science
- Infectious Disease Research
- Surgical Innovation
Background:
- Polytetrafluoroethylene (PTFE) vascular grafts are susceptible to bacterial contamination and infection, leading to significant morbidity.
- Developing effective strategies to prevent graft infection is crucial for improving patient outcomes.
Purpose of the Study:
- To evaluate the efficacy of antibiotic-impregnated biodegradable polymer microspheres in preventing and eradicating bacterial infections in contaminated PTFE vascular grafts.
- To assess the performance of poly(glycolide-co-dl-lactide) amikacin microspheres (PAM) in a canine model.
Main Methods:
- Poly(glycolide-co-dl-lactide) amikacin microspheres (PAM) were prepared to deliver amikacin at two doses (100 mg and 300 mg).
- Mongrel dogs underwent infrarenal aorta replacement with PTFE grafts contaminated with Escherichia coli and Staphylococcus aureus.
- Grafts were covered with PAM (100 or 300 mg) or left untreated (control), with analysis 14 days postoperatively.
Main Results:
- Control grafts showed high rates of clinical infection (7/8) and bacterial contamination (S. aureus in 8/8, E. coli in 5/8).
- No clinical graft infections were observed in PAM-treated groups (P < 0.001).
- PAM 100 and PAM 300 significantly reduced bacterial cultures for S. aureus and E. coli compared to controls.
Conclusions:
- Poly(glycolide-co-dl-lactide) amikacin microspheres (PAM) effectively prevent clinical graft infections.
- PAM demonstrates the ability to completely eradicate standardized bacterial inoculums from contaminated PTFE vascular grafts.
- This antibiotic delivery system shows promise for reducing vascular graft complications.