Gravitational shunts in longstanding overt ventriculomegaly in adults.
OBJECTIVE
A new entity of chronic hydrocephalus was introduced recently in the international literature: longstanding overt ventriculomegaly in adults. Previous experience with this disorder has demonstrated that shunt therapy for such patients involves a considerable risk of overdrainage. In the present study, we aimed to clarify whether this risk could be avoided by use of gravitational shunts.


METHODS
A total of 26 adults (age range, 17-75 yr) with macrocephaly and progressive hydrocephalus symptoms underwent implantation of either an adjustable Codman Hakim gravity-assisted shunt (Codman Medos, LeLocle, Switzerland) plus an Aesculap-Miethke ShuntAssistant (Miethke KG, Kleinmachnow, Germany) or a nonadjustable gravitational shunt (Aesculap-Miethke gravity-assisted valve). The follow-up period averaged 29 +/- 13 months (range, 6-48 mo).


RESULTS
Significant sustained clinical improvement was achieved in 87% of patients. In more than 90% of patients, Evans index decreased postoperatively by less than 10%. No correlation was documented between the degree of ventricle width reduction and clinical improvement. Only two patients developed subdural hematoma, which was caused by insufficient hydrostatic pressure compensation owing to errors in estimation of intraperitoneal pressure.


CONCLUSIONS
Unlike conventional differential pressure shunts, gravitational shunts can be used in the treatment of high-risk patients with longstanding overt ventriculomegaly in adults. Significant risk of overdrainage can be avoided. Gravitational shunts offer a viable alternative to endoscopic third ventriculostomy, provided the choice and adjustment of the shunt opening pressure is based on a correct assessment of the hydrostatic pressure to be compensated for.
Kiefer
Michael
M
Department of Neurosurgery, Saarland University Medical School, Homburg/Saar, Germany. ncmkie@med-rz.uni-saarland.de
Eymann
Regina
R
Strowitzki
Martin
M
Steudel
Wolf-Ingo
WI
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006112:Gravitation; D006801:Humans; D006849:Hydrocephalus / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D007427:Intracranial Pressure / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019736:Prostheses and Implants; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D016896:Treatment Outcome; D017287:Ventriculoperitoneal Shunt / Q000379:methods*; D014696:Ventriculostomy / Q000379:methods*