Cerebrospinal fluid shunt infections in children. A study on the relationship between the etiology of hydrocephalus, age at the time of shunt placement, and infection rate

Comparative study of two customary cerebrospinal fluid shunting systems in early childhood hydrocephalus

The validity of clinical studies on shunt-treated hydrocephalic patients is often hindered by inhomogeneity of the patient population examined, technical devices used, or by other specific factors. In an effort to introduce a homogeneous clinical study on hydrocephalic patients 66 hydrocephalic newborns and infants have been treated exclusively with CORDIS Orbis-Sigma Valve (OSV) System (CORDIS Corporation, Miami, USA) in 1990-1995. The results are compared with an equivalent group of 53 children treated with CODMAN Holter Valve (HV) System (CODMAN Inc., Randolph, USA) during a similar 5-year-period (e.g., 1986-1991). Searching for different reasons of shunt insufficiency in both groups demonstrates a more than double risk of shunt complication for ventriculo-atrial HV treated patients (VA-HV) in comparison with those treated ventriculo-peritoneally with OSV System (VP-OSV): 4.22 versus 1.98 mean surgical procedures per person. The different revision and survival rates are discussed and specific problems are mentioned.

Protein depositions on one hydrocephalus shunt and on fifteen temporary ventricular catheters

Biomaterials are commonly used in modern medicine. Proteins are adsorbed to the surface of the biomaterial immediately after insertion. This report demonstrates the presence of adsorbed proteins in one infected cerebrospinal shunt from a child with hydrocephalus and on fifteen temporary ventricular catheters from adult patients with spontaneous or traumatic brain injuries. Depositions of vitronectin, fibrinogen and thrombospondin-fibronectin to some extent--on the shunt surface was imaged by field-emission scanning electron microscopy. Vitronectin, fibronectin, fibrinogen, and thrombospondin on the ventricular catheters were shown with radio-actively labelled antibodies. Furthermore, protein adsorption from human cerebrospinal fluid to heparinized and unheparinized polymers was studied under flowing conditions in vitro. On heparinized polymer, significantly reduced levels of vitronectin, fibronectin, and thrombospondin were exposed, as measured after 4 hours in vitro perfusion. After 24 hours perfusion, the differences in protein exposition between heparinized and unheparinized polymers were substantially reduced.

Shunt failure in adult hydrocephalus: flow-controlled shunt versus differential pressure shunts--a cooperative study in 289 patients

BACKGROUND

In order to assess the efficiency of flow-controlled shunts in reducing shunt failure in the treatment of adult hydrocephalus (with a special focus on overdrainage complications), a series of 289 patients was analyzed through a retrospective and comparative study performed in three neurosurgical departments.

METHODS

A group of 142 adult patients suffering from hydrocephalus were operated on using a conventional differential pressure (DP) shunt and compared with a group of 147 adult patients operated on using flow-controlled (FC) system (Orbis-Sigma, Cordis). Only the first complication, which required a surgical revision within the first 2 years after shunt implantation, was taken into account for each patient and analyzed using life-table methods.

RESULTS

The actuarial risk of shunt infection in the two groups is respectively 8.3% and 10.9% at 1 year (nonsignificant difference). The actuarial risk of mechanical complications at 1 year is 38% for the DP patients and 10% for the FC patients (p = 0.0001); this difference is largely due to a decrease of complications related to overdrainage phenomenon (14/142 subdural collections were observed in the DP group versus 1/147 in the FC group) (p = 0.0001).

CONCLUSION

The conclusion of this cooperative and retrospective study is that the use of a flow-controlled system decreases the risk of mechanical complications related to the hydrodynamic properties of the shunts used in the treatment of adult hydrocephalus, especially those related to overdrainage.

Long-term follow-up in 233 patients with congenital hydrocephalus

Data on 233 children with congenital hydrocephalus who were operated on in our department from 1964 to 1984 were analyzed. The study was started in January 1990 and was based on questionnaire followed by a psychological examination. Thirty-two patients (13.7%) died during the follow-up period. The average number of operations during the observation period was 2.7; in 166 patients (= 71.2%) the shunt had to be revised at least once. The reason for revision was a mechanical problem in 79.4% and infection in 15.5%. The psychological evaluation in 115 patients showed a normal performance in 62.8%, while 29.8% had mild retardation, evident in speech impairment and/or impaired speech development, in memory and concentration, in poor intellectual performance and decreased performance in school. Severe retardation was seen in 7.4% of cases. Our results showed that the best outcome can be achieved with early shunt implantation. We did not, however, find any correlation between shunt revision rate and psychological results.

Necrotizing enterocolitis complicating the management of posthemorrhagic hydrocephalus

The case notes of all newborn infants with posthemorrhagic hydrocephalus (PHH) operated over the past 10 years at our institution were reviewed to establish the incidence and the effect of necrotizing enterocolitis (NEC) on morbidity and mortality following cerebrospinal fluid (CSF) shunting. Thirteen neonates had both PHH and NEC (group A); 7 of these patients were initially treated by ventriculoatrial (VA) shunt and six by ventriculoperitoneal (VP) shunt. Seventy-five patients had PHH alone (group B); all were treated by VP shunt. Eight patients in group A required an abdominal operation for NEC. The two groups were comparable for birth weight, gestational age, and other complications of prematurity. Episodes of shunt malfunction (infection and/or obstruction) and deaths occurring within 12 months from shunt insertion, in the two groups were compared. Shunt malfunction was more frequent in group A (72%) than in group B (27%) (P < .001). Shunt infection was observed in 39% of group A patients versus 14% in group B (P = .03). Distal shunt obstructions occurred in 28% of group A patients and only 3% of group B patients (P = .001). There were more deaths in group A (62% v 9%; P < .001). Thirty-one percent of group A patients and 4% of group B patients died following shunt complications (P = .006). In group A, there was no significant difference in mortality and shunt malfunction between patients with VA or VP shunts. The method of treatment and the stage of NEC did not influence morbidity and mortality after internal drainage for PHH.(ABSTRACT TRUNCATED AT 250 WORDS)

Shunt implantation: reducing the incidence of shunt infection

Shunt infection remains the foremost problem of shunt implantation after mechanical malfunctions. Diversionary cerebrospinal fluid shunt implantation has a high complication rate, with 5% to 15% of such shunts becoming infected. Of these infections, 70% are diagnosed within 1 month after surgery and more than 90% within 6 months. Shunt infection in the vast majority of cases is therefore a complication of shunt surgery. The authors review their experience with shunt implantation during two time periods. From January, 1978, to December, 1982, 302 children with hydrocephalus underwent 606 operations. Among these children, 47 (15.56%) developed a proven shunt infection, with an incidence of infection per procedure of 7.75%. As a result of this study, a new protocol for shunt procedures involving modifications in the immediate pre-, intra-, and postoperative management of children undergoing shunt implantation was initiated. With this new protocol, 600 children underwent a total of 1197 procedures between January, 1983, and December, 1990. The incidence of shunt infection decreased dramatically, with two infections (0.33%) in 600 patients and a per-procedure rate of 0.17%. The overall annual risk of a shunt infection in the pediatric neurosurgical unit is currently 1.04%.

Infection of cerebrospinal fluid shunts in infants: a study of etiological factors

The aim of this study was to find reasons for the high incidence of cerebrospinal fluid shunt infections seen in neonates. Four-hundred sixty-six consecutive shunt operations were analyzed retrospectively in 294 children, and 60 children were studied prospectively by quantitative sampling of skin bacteria before surgery and by sampling open wounds, shunt catheters, surgical gloves, and airborne bacteria. In total, 110 strains of coagulase-negative Staphylococcus isolated from the skin of 53 children before surgery were then tested for bacterial adherence. Retrospectively, the infection rate for infants younger than 6 months old was 15.7% (28 of 178 procedures), compared with 5.6% (16 of 288 procedures) for older children (p = 0.0005). Of all infections, 67% were due to coagulase-negative Staphylococcus. Age was the only major factor influencing the infection rate. Three of the 60 children studied prospectively developed postoperative shunt infections. All were younger than 6 months and all had high skin bacterial densities before surgery. Contamination during surgery was generally low, but correlated with the preoperative skin bacterial density. Strains of coagulase-negative Staphylococcus with high bacterial adherence were more commonly found in neonates than in older children. High skin bacterial density in neonates before surgery was a risk factor for infection in this study. These results also suggest that there is selection of more virulent strains of coagulase-negative Staphylococcus on the skin of neonates. Prevention of shunt infections in this high-risk group could be facilitated by the reduction of skin bacterial density before surgery using chlorhexidine shampoos and by the elimination of contamination by skin bacteria during surgery using packs soaked in an antiseptic agent to isolate wound edges and glove-changing before handling the shunt.

Avoidable factors that contribute to the complications of ventriculoperitoneal shunt in childhood hydrocephalus

A personal series of 80 consecutive children who underwent ventriculoperitoneal shunting for hydrocephalus has been followed up for a period of from 6 months to 6.5 years. Complications occurred in 8 patients; these included partial occlusion of the ventricular catheter in 2, infection in 2, peritoneal catheter-valve disconnection with migration of the catheter into the peritoneal cavity in 2, fracture of the peritoneal catheter just below the valve in 1, and failure of the peritoneal cavity to absorb cerebrospinal fluid in another. Analysis of the results in the present series showed that the complications result from the technique. The operative procedures responsible for a low complication rate in the present series are described. It is concluded that to avoid shunt complications, attention must be paid to the following factors: meticulous asepsis; good surgical technique, including testing of the shunt system to make certain that the correct opening pressure is present; elimination of contact between the shunt system and the patient's skin; placement of the valve under a pericranial flap; positioning the tip of the ventricular catheter just in front of the foramen of Monro and that of the peritoneal catheter in the pelvic peritoneal cavity.