Abnormalities of Water Metabolism after Surgery for Optic/Chiasmatic Astrocytomas in Children

Abstract

A major concern during the early postoperative period after surgical resection 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 and 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 development of these complications. A retrospective chart review of children with optic/chiasmatic gliomas undergoing operations on the tumor was performed and the pre- and postoperative radiographs reviewed by an independent neuroradiologist. There were 11 patients who underwent 13 operations for either resection (n = 9) or biopsy (n = 4) of their optic chiasm tumor. The extent of resection in patients undergoing more than simple biopsy ranged from 83 to 99%, and all patients with resection had exophytic tumor extending into the hypothalamus. Postoperative syndrome of inappropriate antidiuretic hormone secretion (SIADH) and/or diabetes insipidus occurred after 8 of the 9 tumor resections and was associated with significant morbidity. No disturbance of water metabolism occurred after biopsy only. In patients with SIADH, the urinary sodium 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 reliable way to avoid rapid fluctuations in serum sodium and to avoid the morbidity of diabetes insipidus or SIADH and is recommended in the postsurgical patients who cannot regulate fluid intake.

Management of Optic Chiasmatic/ Hypothalamic Astrocytomas in Children

“…The difficult management of perioperative derangements of salt and water balance in this population deserves more consideration than has been given in the past. 26 In this small study, there did not appear to be any difference in the probability of tumor progression or time to progression among the surgical groups undergoing variable degrees of resection. There was a high progression rate for those tumors treated by surgical resection alone, with all but two out of the eight surviving patients requiring chemotherapy and/or radiotherapy at some time after a radical resection to obtain tumor control.…”

Endocrine Function and Water Metabolism in Children and Adolescents with Surgically Treated Intra/Parasellar Tumors

“…The outcome of hydroelectrolytic alterations in the peri-operative period is not totally predictable ' 5 ' 16 . In our experience, in accordance with the literature 17 , water metabolism derangements could be seen in any patient, including those with presurgical intact hydroelectrolytic function.…”

Hourly oral sodium chloride for the rapid and predictable treatment of hyponatremia

“…A central basis for the hyponatremia was also considered. Gliomas arising from the optic chiasm have been associated with hypernatremia from central diabetes insipidus or osmoreceptor dysfunction [ 29 ]; hyponatremia/SIAD has been reported following surgery [ 30 ] and de novo in a case with features similar to the present one [ 31 ]. Abnormal adrenocortical and thyroid function can accompany pituitary failure and can give rise to an SIAD-like picture (reviewed in: [ 7 ]).…”