Treatment of hydrocephalus in adults by placement of an open ventricular shunt

Object. Ventricular shunt placement is the neurosurgical procedure most fre quently associated with complications. Over the years, it has been a growin g concern that the performance of most shunting devices does not conform to physiological parameters. An open ventriculoperitoneal (VP) bypass with a peritoneal catheter for which the cross-sectional internal diameter was 0.5 1 mm as a distinctive element for flow resistance was evaluated for use in the treatment of adult patients with hydrocephalus. Methods. During a 2-year period, open shunts were surgically implanted in 5 4 adults with hydrocephalus; conventional shunts were implanted in 80 match ed controls. Periodic evaluations were performed using neuroimaging studies and measures of clinical status. All patients were followed from 12 to 36 months, 18.5 +/- 4 months for patients with the open shunt and 19.1 +/- 8.1 months for controls (mean +/- standard deviation). The device continued to function in 50 patients with the open shunt (93%) and in 49 controls (61%; p < 0.001). The Evans index in patients with the open shunt was 0.33 +/- 0 .09 throughout the follow up. No cases of infection, overdrainage, or slit ventricles were observed; the index in controls was 0.28 +/- 0.08; 60% of t hem developed slit ventricles. During the follow-up period occlusion occurr ed in four patients with the open shunt (7%) and in 31 controls (39%; p < 0 .001). Conclusions. The daily cerebrospinal fluid (CSF) drainage through the open VP shunt is close to 500 mi of uninterrupted flow propelled by the hydrokin etic force generated by the combination of ventricular pressure and siphoni ng effect. It complies with hydrokinetic parameters imposed by a bypass con nection between the ventricular and peritoneal cavities as well as with the physiological archetype of continuous flow and drainage according to CSF p roduction. The open shunt is simple, inexpensive, and an effective treatmen t for hydrocephalus in adults.