430o Direct Observation on Bactiseal ™ Catheter by Scanning Electron Microscopy – 4 Cases Studies

Xuemei Liang1, Anfeng Wang2, Haiying Tang2, Ting Cao2, Kotz Katherine3, Yandong Zhou3, James P. Mcallister II4, Steven O. Salley2, and K. Y. Simon Ng2. (1) Department of Chemical Engineering and Materials Science, Wayne State University, 5050 Anthony Wayne Dr., Detroit, MI 48202, (2) Department of Chemical Engineering and Materials Sciences, Wayne State University, 5050 Anthony Wayne Dr., Detroit, MI 48202, (3) Wayne State University, 5050 Anthony Wayne Dr., Detroit, MI 48202, (4) Department of Neurological Surgery, School of Medicine, Wayne State University, 5050 Anthony Wayne Dr., Detroit, MI 48202

Infection continues to be one of the major complications of cerebrospinal fluid shunting procedures. Treatment of CSF shunts with antimicrobial agents has shown great potential for preventing shunt infections. The development of an antibiotic-impregnated silicone catheter yielded excellent results in infection prevention and treatment in vitro as well as in vivo. The commercially available CODMAN BACTISEAL catheter, loaded with 0.15% clindamycin and 0.054% rifampicin, slowly releases these antibiotics, providing protection against bacterial colonization for up to 28 days. In this study, four implanted CODMAN BACTISEAL ™ catheters (supplied by Michigan Children's Hospital, Codman, Johnson & Johnson, Boston, MA) , used for the treatment of hydrocephalus patients, were studied with the scanning electron microscopy (SEM). More drug crystals were observed on external surfaces of catheter than those on lumen surfaces. Crystal structure and irregular holes were observed on drainage holes and the external and internal surfaces. S. epidermidis adhesion on infected catheter was found. The clues about the nature of implanted shunt physical morphology are used to correlate with the most common causes leading to the malfunction and infection of the shunt. Moreover, the silicone surface has been modified with biopolymers (heparin and hyaluronan) and selfassembled monolayers (octadecyltrichlorosilane-OTS and fluoroalkylsilane -FAS) to investigate the effect of polymer coating to minimize bacterial infection (S. epidermidis) and cell adhesion (astrocyte and choroid plexus). It was found that FAS surfaces significantly reduced cell proliferation and bacterial adhesion. Silicone shunts coated with self-assembled monolayers may be suitable for future clinical applications to improve the treatment of hydrocephalus.