Calcific deposits on degraded shunt catheters: long-term follow-up of V-P shunts and late complications in three cases.

OBJECT: Three cases with late complications and nine cases without late complications are presented to demonstrate the long-term results of ventriculoperitoneal (V-P) shunting, particularly those concerning degradation and mineral deposits of shunt catheters.
METHODS: Plain X-rays were taken in every case to detect any calcification. The catheters removed following late complications were examined in a scanning electron microscope (SEM). Spectroscopy and conventional histology were also performed.
CONCLUSION: Routine histology, spectroscopy, and SEM revealed that the mineral deposits consisted of hydroxyapatite. Plain X-ray and operative findings showed that the most extensive calcification was present in the neck, where the catheters were subject to heavy mechanical stress. No calcification was detected on catheters that did not contain barium particles. Our findings indicate that mechanical stress contributes to the process of degradation, and that barium sulfate admixed with silicone during the manufacturing process might accelerate late complications owing to the formation of cracks in the catheters and by enhancing the nucleation rate.