Peter a.Woerdeman, m.D., ph.D., and david d.Cochrane, m.D., f.R.C.S.C.Disruption of silicone valve housing in a codman hakim precision valve with integrated siphonguard.Journal of neurosurgery pediatrics 13 (2014).Doi: 10.3171/2014.2.Peds13436.Authors of this report describe 2 patients who had undergone shunt insertion for hydrocephalus and who, at 6 weeks or 9 months after their last revision, presented with symptoms of shunt dysfunction and csf collections at the valve site.At the ensuing shunt revision in both patients, the silicone housing was fractured and the siphonguard was disconnected from the codman hakim precision flat-bottom valve.The cause of these failures was not clear since manipulation, bending, and twisting of the valves were not thought to have occurred during implantation.A review of the fda¿s manufacturer and user facility device experience (maude) database revealed 58 cases of silicone housing failure in the codman hakim precision valve with integrated siphonguard since the year 2000.A single report was found in the databases administered by the canadian medical devices sentinel network (cmdsnet).The codman hakim precision valves with integrated siphonguard are delicate devices that do not withstand the intraoperative handling tolerated by other valves.When these valves are implanted, gentle handling and wide exposures are needed to minimize the risk of valve damage.Valves should be handled according to the manufacturer¿s instructions.However, in light of this particular pattern of failure, it is recommended that the manufacturer redesign this valve to provide handling tolerance that is characteristic of other valves on the market.The featured cases illustrate the importance of the surgeon¿s role in postmarket surveillance of medical devices and reporting device failures to the responsible agencies and manufacturers.Reported events.This patient had presented with posthemorrhagic nonobstructive hydrocephalus in infancy.An endoscopic third ventri culostomy did not control her hydrocephalus, and thus a vp shunt was placed using an occipital entry point with frontal horn tip placement.Catheters were barium impregnated, the distal catheter was open-ended, and the valve was a ps medical differential pressure, medium pressure silicone valve.Thirteen years later the patient returned with symptoms of shunt obstruction.Imaging suggested a ventricular catheter fracture above the catheter-to-valve connection, which was confirmed when the ventricular catheter was replaced and the valve was upgraded to another manufacturer's valve.The ventricular catheter was replaced as part of a revision due to the valve of another manufacturer's was replaced because of a distal subcutaneous displacement.The distal catheter was replaced due to separation at the straight connector.
|