Premature fractures of platinum-cured Silastic shunts.
Experience with one unitized ventriculoperitoneal (VP) shunt system has disclosed an unacceptably high rate of premature distal shunt tube fracturing. From March, 1986, to February, 1989, 114 new or replacement unitized VP shunts were placed; the patients were followed through November, 1991. Twenty-two (19.3%) returned with peritoneal limb fractures, with a mean time from shunt implantation to fracture of 31.5 +/- 11.3 months (range 15-62 months). All shunts broke in the neck 1.1-11.2 cm below the valve. Of the 22 cases, there were no instances of infection, previous peritoneal limb revisions, or recognizable iatrogenic shunt injury at placement. These fractures also occurred earlier than the usual time expected for biodegradation of shunt tubing. The Silastic tubing in all of these shunts had been manufactured using a more recent platinum-curing process. This tubing has decreased elastance and is more brittle than tubing cured with the previously used dichlorobenzoyl peroxide (DCBP) catalyst. Our studies suggest that the premature shunt tube fractures were related to changes in physical characteristics of the platinum-cured Silastic tubing. Therefore, the DCBP-cured Silastic is to be considered preferable for shunting products. Neurosurgeons are asked to report recurring patterns of shunt system failure.
Ramsey
D B
DB
Department of Neurosurgery, Arkansas Children's Hospital, University of Arkansas for Medical Sciences, Little Rock 72202.
Chadduck
W M
WM
D001585:Benzoyl Peroxide / Q000031:analogs & derivatives / Q000494:pharmacology; D002557:Cerebrospinal Fluid Shunts / Q000009:adverse effects*; D004868:Equipment Failure; D006801:Humans; D008855:Microscopy, Electron, Scanning; D010537:Peritoneum; D010984:Platinum / Q000494:pharmacology; D012826:Silicone Elastomers; D012828:Silicones; D013997:Time Factors
D012826:Silicone Elastomers; D012828:Silicones; C020714:bis(2,4-dichlorobenzoyl)peroxide; D010984:Platinum; D001585:Benzoyl Peroxide