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.

[Treatment of chronic hydrocephalus in adults by flow-regulated shunt. Apropos of a series of 46 patients]. / Traitement de l'hydrocéphalie chronique de l'adulte par dérivation à débit régulé. A propos d'une série de 46 patients.

46 patients, 24 males and 22 females (mean age: 68.3 years), with chronic hydrocephalus were operated on by a variable-resistance, flow-regulated shunt. The selecting criteria before surgery were essentially clinical (association of gait disturbances, dementia and urinary incontinence, positive lumbar puncture withdrawal test) in consideration with the retrospective and cooperative study of this series. Hydrocephalus had an etiology in 23 cases (50%): 4 cases of trauma (8%), 9 cases of tumors (20%), 9 cases of subarachnoid haemorrhage (20%) and 1 case of infection (2%). The average follow-up is 17 months (median: 12 months). 20 patients (43.5%) have an excellent result (normal life), 16 patients (34.8%) have a good result (residual symptomatology compatible with a self-governing life), 5 patients (10.9%) have a poor result (residual symptomatology non compatible with a self-governing life), 2 patients (4.3%) have a bad result (unchanged symptomatology). 3 patients died after the surgical procedure. 3 patients had an infectious complication of their shunt (actuarial risk of infectious complication at one year and a half: 7%). 2 patients presented a non infectious complication, one chronic subdural hematoma and one bad insertion of the proximal catheter (actuarial risk of mechanical complication at one year and a half: 4.4%).