title: A randomized, controlled study of a programmable shunt valve versus a conventional valve for patients with hydrocephalus. Hakim-Medos Investigator Group.
abstract: OBJECTIVE
  A multicenter prospective randomized controlled study was performed to assess the safety and efficacy of a Codman Hakim programmable shunt valve (Codman/Johnson & Johnson, Raynham, MA) versus a conventional valve system of the surgeon's choice for the treatment of patients with hydrocephalus.
  
  
  METHODS
  Enrollment was stratified on the basis of whether the patient was undergoing initial shunt insertion or revision of an existing valve system at study entry. Study end points were: 1) valve explantation, and 2) shunt failure (surgical intervention for any component of the shunt). A total of 377 patients were enrolled onto the study, with 235 undergoing first shunt insertion (119 experimental, 116 control) and 142 undergoing revisions (75 experimental, 67 control).
  
  
  RESULTS
  During a follow-up interval of 104 weeks after the first implantation on-study, explantation of the valve was required in 62 (32%) of 194 experimental valves, compared with 71 (39%) of 183 control valves. Two-year survival rates of the original shunt without revision of any component were 52% (62 of 119) and 50% (58 of 116) in experimental and control patients, respectively, who underwent initial shunt insertion, and 43% (32 of 75) and 43% (29 of 67) in experimental and control patients, respectively, who underwent replacement of an existing valve. No statistically significant difference was observed between experimental and control patients in the survival of either the valve or the overall shunt system. Control of hydrocephalus as assessed symptomatically and by imaging was comparable in the two treatment groups. Although problems related to inability to achieve the desired pressure setting were reported in 22 experimental valves, in all but four instances no additional programming was attempted because the patients were functioning well clinically. The most common reasons cited for valve explantation and shunt revision were infection (9.8% frequency in the overall cohort) and proximal shunt malfunction, which occurred with comparable frequency in the experimental and control groups.
  
  
  CONCLUSIONS
  Safety and efficacy of the Codman Hakim programmable shunt valve is comparable to conventional valves in the overall population of patients with hydrocephalus. However, the current study was not designed to assess the efficacy of programmable versus conventional valves in the management of individual hydrocephalus problems, and it had insufficient statistical power to support such comparisons. This study provides a rationale for examining whether the theoretical advantages of a programmable valve for managing challenging hydrocephalus problems can translate into meaningful improvements in shunt and valve survival.
authors.affiliation: Department of Neurosurgery, Children's Hospital of Pittsburgh, Pennsylvania 15213, USA.
authors.forename: I F
authors.initials: IF
authors.lastname: Pollack
authors.forename: A L
authors.initials: AL
authors.lastname: Albright
authors.forename: P D
authors.initials: PD
authors.lastname: Adelson
mesh_terms: D000293:Adolescent; D000328:Adult; D015170:Cerebrospinal Fluid Pressure / Q000502:physiology; D002557:Cerebrospinal Fluid Shunts / Q000295:instrumentation*; D002648:Child; D002675:Child, Preschool; D019544:Equipment Failure Analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006849:Hydrocephalus / Q000134:cerebrospinal fluid / Q000601:surgery*; D007223:Infant; D008297:Male; D008838:Microcomputers; D011183:Postoperative Complications / Q000134:cerebrospinal fluid / Q000209:etiology / Q000601:surgery; D011446:Prospective Studies; D012086:Reoperation; D012984:Software