Comparison of shunt infection incidence in high-risk subgroups receiving antibiotic-impregnated versus standard shunts.

BACKGROUND

Shunt infection is a morbid complication of CSF shunting. Though antibiotic-impregnated shunt (AIS) systems decrease shunt infections by preventing bacterial colonization following device implantation, their effectiveness in populations at high risk for infection has recently been disputed. We set out to determine whether the categorical switch to AIS systems at our institution has resulted in a decreased incidence of shunt infection in high-risk pediatric patients.

METHODS

We retrospectively reviewed the records from all pediatric patients undergoing CSF shunt procedures at The Johns Hopkins Hospital over a 10-year period between January 1997 and December 2007. During the 5.75 years prior to October 2002, all CSF shunts included standard, non-AIS catheters. During the 4.25 years after October 2002, all CSF shunts included AIS catheters. High-risk subgroups were defined a priori as prematurity (<35 weeks gestational age), shunts placed immediately post-meningitis, conversion of external ventricular drains (EVD) to shunt, and replacement of nosocomial shunt infection in patients requiring prolonged hospital stay (>1 month).

RESULTS

A total of 544 pediatric patients underwent 1,072 shunt placement procedures (502 AIS, 570 non-AIS). Of patients with non-AIS catheters, 64 (11.2%) experienced shunt infection, whereas only 16 (3.2%) patients with AIS catheters experienced shunt infection (p<0.001). AIS versus non-AIS was associated with decreased shunt infection in premature neonates [three (5.5%) vs. seven (20.0%), p=0.030], acutely following bacterial meningitis [two (5.7%) vs. nine (25.0%), p=0.043], when converting EVD to shunts [zero (0%) vs. four (13.3%), p=0.030], and in patients with prolonged hospital stay>1 month [three (5.3%) vs. 12 (18.5%), p=0.022]. Staphylococcus aureus was the most common infectious agent for both non-AIS (81.3%) and AIS (75.0%) systems.

CONCLUSION

The introduction of AIS catheters into our institutional practice has reduced the incidence of shunt infection in pediatric populations at highest risk for infection. AIS catheters are effective instruments to prevent peri-operative colonization of CSF shunt components.