Hyponatremia following endoscopic third ventriculostomy: a report of 5 cases and analysis of risk factors.
OBJECTIVE
Electrolyte and endocrinological complications of endoscopic third ventriculostomy (ETV) are infrequent but serious events, likely due to transient hypothalamic-pituitary dysfunction. While the incidence of diabetes insipidus is relatively well known, hyponatremia is not often reported. The authors report on a series of 5 patients with post-ETV hyponatremia.


METHODS
The records of patients undergoing ETV between 2008 and 2010 were reviewed. All ETVs were performed with a rigid neuroendoscope via a frontal bur hole, standard third ventricle floor blunt perforation, Fogarty catheter dilation, and intermittent normal saline irrigation. Postoperative MR images were evaluated for endoscope tract injury as well as the trajectory from the bur hole center to the fenestration site.


RESULTS
Thirty-two patients (20 male and 12 female) underwent ETV. Their median age was 6 years (range 3 weeks-28 years). Hydrocephalus was most commonly due to nontumoral aqueductal stenosis (43%), nontectal tumor (25%), or tectal glioma (13%). Five patients (16%) had multicystic/loculated hydrocephalus. Five patients (16%) developed hyponatremia between 1 and 8 days following ETV, including 2 patients with seizures (1 of whom was still hospitalized at the time of the seizure and 1 of whom was readmitted as a result of the seizure) and 3 patients who were readmitted because of decline in their condition following routine discharge. No hypothalamic injuries were noted on imaging. Univariate risk factors consisted of age of 2 years or less (p = 0.02), presence of cystic lesions (p = 0.02), and ETV trajectory angle 10° or more from perpendicular (p = 0.001).


CONCLUSIONS
Endoscopic third ventriculostomy is a well-tolerated procedure but can result in serious complications. Hyponatremia is rare and may be more likely in younger patients or those with cystic loculations. Patients with altered craniometry may be at particular risk with a rigid endoscopic approach requiring greater manipulation of subforniceal or hypothalamic structures.
Department of Neurosurgery, University of Pennsylvania Medical Center, Philadelphia 19104, USA. shihshan.lang@uphs.upenn.edu
Shih-Shan
SS
Lang
Joel A
JA
Bauman
Michael W
MW
Aversano
Matthew R
MR
Sanborn
Arastoo
A
Vossough
Gregory G
GG
Heuer
Phillip B
PB
Storm
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000209:etiology / Q000601:surgery*; D007010:Hyponatremia / Q000097:blood / Q000209:etiology*; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D044583:Neuroendoscopy; D010359:Patient Readmission; D012189:Retrospective Studies; D012307:Risk Factors; D012964:Sodium / Q000097:blood*; D020542:Third Ventricle / Q000601:surgery; D016896:Treatment Outcome; D014696:Ventriculostomy / Q000009:adverse effects* / Q000379:methods; D055815:Young Adult
D012964:Sodium