J. Daaboul et P. Steinbok, ABNORMALITIES OF WATER METABOLISM AFTER SURGERY FOR OPTIC CHIASMATIC ASTROCYTOMAS IN CHILDREN/, Pediatric neurosurgery, 28(4), 1998, pp. 181-185
A major concern during the early postoperative period after surgical r
esection of optic chiasmatic gliomas is the derangement of sodium and
water metabolism which may add to the morbidity of the procedure. The
purpose of this study was to characterize the abnormalities of water a
nd sodium metabolism in children with optic chiasmatic gliomas treated
surgically at British Columbia's Children's Hospital and to identify
therapeutic modalities which might prevent or ameliorate the developme
nt of these complications, A retrospective chart review of children wi
th optic/chiasmatic gliomas undergoing operations on the tumor was per
formed and the pre- and postoperative radiographs reviewed by an indep
endent neuroradiologist, There were 11 patients who underwent 13 opera
tions for either resection (n = 9) or biopsy (n = 4) of their optic ch
iasm tumor, The extent of resection in patients undergoing more than s
imple biopsy ranged from 83 to 99%, and all patients with resection ha
d exophytic tumor extending into the hypothalamus. Postoperative syndr
ome of inappropriate antidiuretic hormone secretion (SIADH) and/or dia
betes insipidus occurred after 8 of the 9 tumor resections and was ass
ociated with significant morbidity, No disturbance of water metabolism
occurred after biopsy only. In patients with SIADH, the urinary sodiu
m level rose markedly 6-12 h prior to the development of hyponatremia,
and it was concluded that this was a valuable predictor of impending
hyponatremia, Replacement of urine output was noted to be the most rel
iable way to avoid rapid fluctuations in serum sodium and to avoid the
morbidity of diabetes insipidus or SIADH and is recommended in the po
stsurgical patients who cannot regulate fluid intake.