Antibiotic-Impregnated Shunt Catheters and Shunt Infections Joseph Noggle Dan Sciubba, MD George I. Jallo, MD Johns Hopkins University, Division of Pediatric Neurosurgery, Baltimore, Maryland

Shunt Infection North American infection rate averages 5-15% Late shunt infection rate 12.1% (study of 1700+ patients) Majority occur less than 4 months postoperatively Even when successfully treated, infections are associated with reduced IQ and school performance, increased risk of seizures, and psychomotor retardation Infection is a common cause of shunt failure with an associated increased risk of morbidity and mortality

Antibiotic-impregnated shunts Infection most often results from colonization by normally nonpathogenic skin flora at the time of implantation Antibiotic-impregnated shunt (AIS) systems decrease colonization of shunt components by staphylococcal species conferring a putative protection against early shunt infections Although such systems have been clinically shown to decrease the incidence of early shunt infections (< 6 months), it is unclear if such exposure to prolonged antibiotics leads to an increased incidence or virulence of late shunt infections (> 6 months). In this study, we evaluated the incidence of late shunt infection after introduction of an AIS system in a pediatric hydrocephalus population.

Bactiseal® Catheters

BACTISEAL® Bactiseal silicone catheters are indicated for use in the treatment of hydrocephalus as a component of a shunt system when draining or shunting cerebral fluid is indicated. Bactiseal silicone catheters have been shown in laboratory studies to reduce the colonization of gram positive bacteria on tubing surfaces.

Methods Prospective cohort of all pediatric patients undergoing CSF shunt insertion over a 33-month-period from 10/02 to 6/05. During this period, > 95% of all CSF shunts included antibiotic-impregnated shunt catheters1 All patients were followed for >9 months, and all shunt-related complications, including shunt infection, were evaluated. The incidence of early (<6 months) and late (>6 months) infections were calculated. The incidence of late shunt infections (LSI) were compared to historical controls. 1Bactiseal; Codman, Johnson & Johnson, Boston, MA

Patient Population Total Patients 153 Total Procedures 262 Age (yrs) 8 [3.0-13.0] Male/Female 81 (53%) / 72 (47%) Premature 52 (34%) Initial shunt 72 (27.5%) Shunt Revisions 190 (72.5% of all procedures) Patients with revisions 55 (36% of all patients)* Proximal 124 (62.3% of revisions) Distal 43 (22.6% of revisions) Entire 23 (12 % of revisions) Shunt type VP 239 (91%) VA 10 (3.8%) VPl 7 (2.8%) CP 5 (2%) Valve Type Programmable 143 (54.5%) Set Pressure 98 (37.4%) Unspecified 21 (8%) *Revisions: 43 patients had revisions within 6 months of prior operation (78% of pts with revisions)  

Patient Population Etiology of Hydrocephalus Congenital 59 (39%) Post-hemorrhagic 34 (22.2%) Myelodysplasia 19 (12.4%) Tumor 17 (11%) Dandy-Walker 4 (2.6%) Post. Fossa Cyst 4 (2.6%) Meningitis 3 (2%) Aqueductal Stenosis 2 (1.3%) Other* 11 (7%) Type of Hydrocephalus Communicating 82 (53.5%) Non-communicating 62 (40.5%) Unclear 9 (6%) *Other includes: after hemispherectomy, trauma, and unknown

Follow Up Of these 153 patients: 129 (84.3%) were followed closely for at least one year (mean: 21.7 months; range: 13 – 46 months) 21 patients were lost to follow up - usually after the first post-operative visit - (within two months of surgery) 3 patients died at: 2 months, 2 months, and 4 months, respectively None of these three patients died of shunt malfunction nor shunt infection

Results 10 (3.82%) AIS shunts became infected within 6 months of implantation (early shunt infection) The average length of time after surgery at which the shunt infection was detected was 4.5 weeks (range 2 weeks – 8 weeks). No patients with antibiotic-impregnated catheters experienced shunt infection after 6-months postoperatively 21.7 month mean follow up; range: 13-46 months

Infectious Agent Organism Early (< 6 months) Late (>6 months) Staphylococcus aureus* 4 0 Staphylococcus, coagulase negative 3 Corynebacteria species 1 Gram negative rod 2   Total 10 0 *all methicillin-sensitive staphylococcus aureus (MSSA) infections

Shunt infection as a function of time after insertion (“shunt survival”)

Conclusions No late CSF shunt infections were noted after introduction of an antibiotic-impregnated shunt (AIS) system into a pediatric hydrocephalus population. Although continued long term follow up is necessary to get an estimate of the true incidence of LSI, it appears that the use of such systems will continue to decrease early shunt infections without placing patients at risk for delayed complications. Future double-blinded randomized controlled trials would be ideal means to corroborate the results from this prospective observational study