Association between ventricular shunt catheter calcifications and the development of shunt fracture

Calcifications along ventricular catheters have been associated with shunt fractures although it is unknown whether their development predicts whether and when the shunts will fracture.

To determine whether extracranial calcifications found on a radiographic shunt series predicts whether a patient will experience a shunt catheter fracture or complication.

A retrospective review was performed of pediatric patients with a ventricular shunt placed before 18 years of age and radiographic shunt series. Two thousand, six hundred and thirty shunt series in 523 patients (301 male) were reviewed to identify the development of calcifications around the catheter and fracture. Fifty-one patients were excluded for preexisting calcifications with shunt fracture. (48) Absence of shunt (2) or age (1). Analysis included descriptive statistics, odds ratio and chi-square test results.

Four hundred seventy-two patients were included. Of the 59 shunts in 58 patients that developed calcifications, 23 went on to fracture (39%). Forty shunts without calcification in 37 patients developed fractures. There is a significant positive association between calcification and fracture (Χ²=39.1, P<0.01). It is 6.12 times more likely that a fractured shunt had calcifications compared to a non-fractured shunt having calcifications. Calcifications appeared within an average of 9 years, 10 months (range: 4-14 years) after shunt insertion. Shunt fractures occurred within an average of 5 years, 2 months (range: 6 months-9 years) after the appearance of calcifications with a median patient age of 14.6 years. Nearly all fractures were at or adjacent to the calcifications, most commonly in the neck (17/23; 73.9%).

Shunt calcification represents a significant risk for catheter fracture in the pediatric population. Early intervention or closer interval follow-up may be indicated in those found to have calcifications.