A multicenter prospective cohort study of the Strata valve for the management of hydrocephalus in pediatric patients.

[hydrocephalus with stenosis of the aqueduct of sylvius]

Previous reports suggest that adjustable valves may improve the survival of cerebrospinal fluid shunts or relieve shunt-related symptoms . To evaluate these claims , the authors conducted a prospective multicenter cohort study of children who underwent placement of Strata valves .Patients undergoing initial shunt placement (Group 1 ) or shunt revision (Group 2 ) were treated using Strata valve shunt systems . Valves were adjustable to five performance level settings by using an externally applied magnet . The performance levels were checked using an externally applied hand tool and radiography . Patients were followed for 1 year or until they underwent shunt revision surgery . Between March 2000 and February 2002 , 315 patients were enrolled in the study . In Group 1 (201 patients ) the common causes of hydrocephalus were myelomeningocele (16 %), aqueductal stenosis (14 %), and hemorrhage (14 %). The overall 1 -year shunt survival was 67 %. Causes of shunt failure were obstruction (17 %), overdrainage (1 .5 %), loculated ventricles (2 %), and infection (10 .6 %). Patients in Group 2 (114 patients ) were older and the causes of hydrocephalus were similar . Among patients in Group 2 the 1 -year shunt survival was 71 %. There were 256 valve adjustments . Symptoms completely resolved (26 %) or improved (37 %) after 63 % of adjustments . When symptoms improved or resolved , they did so within 24 hours in 89 % of adjustments . Hand -tool and radiographic readings of valve settings were the same in 234 (98 %) of 238 assessments .The 1 -year shunt survival for the Strata valve shunt system when used in initial shunt insertion procedures or shunt revisions was similar to those demonstrated for other valves . Symptom relief or improvement following adjustment was observed in 63 % of patients . Hand -tool assessment of performance level settings reliably predicted radiographic assessments .