Hydrocephalus in achondroplasia: efficacy of endoscopic third ventriculostomy

Abstract

OBJECTIVE Ventriculoperitoneal shunts (VPSs) for hydrocephalus in patients with achondroplasia are known to have a higher failure rate than in other hydrocephalus populations. However, the etiology of hydrocephalus in this group is considered “communicating,” and, therefore, potentially not amenable to endoscopic third ventriculostomy (ETV). ETV has, nonetheless, been reported to be successful in a small number of patients with achondroplasia. The authors aimed to investigate the long-term results of ETV in this population. METHODS Patients with achondroplasia who had undergone surgical treatment for hydrocephalus (ETV or VPS placement) were identified. In patients who had undergone ETV, medical records and neuroimages were reviewed to determine ventricular volumes and frontal and occipital horn ratios (FOHRs) pre- and postoperatively, as well as the incidence of surgical complications and reoperation. Patients who underwent VPS placement were included for historical comparison, and their medical records were reviewed for basic demographic information as well as the incidence of surgical complications and reoperation. RESULTS Of 114 pediatric patients with achondroplasia referred for neurosurgical consultation, 19 (17%) were treated for hydrocephalus; 10 patients underwent ETV only, 7 patients underwent VPS placement only, and 2 patients had a VPS placed followed by ETV. In patients treated with ETV, ventricular volume and FOHRs were normal, if measured at birth, and increased significantly until the time of the ETV. After ETV, all patients demonstrated significant and sustained decreases in ventricular measurements with surveillance up to 15 years. There was a statistically significant difference in rates of repeat CSF surgery between the ETV and VPS cohorts (0/12 vs 7/9, p < 0.001). CONCLUSIONS ETV was efficacious, safe, and durable in the treatment of hydrocephalus in patients with achondroplasia. Although many studies have indicated that hydrocephalus in these patients is “communicating,” a subset may develop an “obstructive” component that is progressive and responsive to ETV.

Growth patterns of young achondroplasia patients in Korea and predictability of neurosurgical procedures

“…There have been several works of literature that ETV was effective in treating achondroplasia patients with hydrocephalus [7,14,25,26]. To our knowledge, it has been reported that 19 achondroplasia patients with hydrocephalus were treated with ETV.…”

“…The advantage of ETV is that there is no mechanical failure or infection of the device, as in the VP shunt. Furthermore, the malfunction rate of VP shunt is high in achondroplasia patients (48% in children at 5 years), and the recurrence rate of hydrocephalus after ETV is low in reported cases (the success rate at 6 months after surgery was reported to be 75.9%) [7,14]. However, the steep angle of the third ventricular oor in achondroplasia patients often hinders a safe ETV procedure.…”

“…VP shunt was performed if initial FMD did not reverse the progressive ventriculomegaly and associated symptoms or if there was no craniovertebral stenosis necessitating FMD. Endoscopic third ventriculostomy (ETV) was recently considered a treatment option for some patients requiring VP shunt [7,14,25,26].…”

“…Clinical surveillance and application of foramen magnum decompression (FMD) is the solution to this problem [1,5,[11][12][13]. The other serious trouble is the development of hydrocephalus [14]. Ventricular enlargement with thinning of the cerebral mantle is often observed with progressively increased head circumference (HC).…”