Possible harmful effects on central nervous system cells in the use of physiological saline as an irrigant during neurosurgical procedures.
BACKGROUND
Physiologic saline is routinely used as an irrigant in neurosurgery especially in Japan. Cerebrospinal fluid (CSF) differs from physiologic saline in its concentration of inorganic salts, osmolality, and pH and is completely different insofar as it contains glucose, protein, cholesterol, and other lipids. The present study was designed to compare the possible functional and morphologic deleterious influence of these differences on cultured rat neural cells using saline (S), Ringer's solution with glucose (Lactec G, LG; Otsuka Pharmaceutical Co.; Tokyo, Japan) and without glucose (Lactec, L; Otsuka Pharmaceutical Co.), and an artificial CSF (ACSF).


METHODS
Primary cultured rat neurons and astrocytes were divided into five groups according to the medium used, the four experimental groups (ACSF, L, LG, and S) and one control group (C). At various time points up to 24 hours, the rhodamine 123 uptake by neuronal or astrocytic cellular mitochondria was evaluated as cell function assessment. Morphologic assessment for both neuron and astrocyte culture was carried out with scanning electron microscopy (SEM) at the 24-hour time point.


RESULTS
SEM showed little difference between the C and ACSF groups, whereas morphologic deterioration was particularly severe in the S group for both neurons and astrocytes. In the case of neuronal mitochondrial activity, the L and S groups demonstrated respectively severe and some deterioration, particularly in the mitochondria of the neuronal processes. The deleterious effects in mitochondrial activity of the S group were even more apparent in the astrocytic cells.


CONCLUSIONS
These results suggest that physiologic saline, when used as an irrigant in neurologic surgery, might in some circumstances cause damage to exposed and compromised neural cells.
Uchida
Koichi
K
Department of Neurosurgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan.
Yamada
Motoyuki
M
Hayashi
Takuro
T
Mine
Yutaka
Y
Kawase
Takeshi
T
D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000473:pathology; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects* / Q000473:pathology / Q000648:ultrastructure; D004622:Embryo, Mammalian; D005456:Fluorescent Dyes; D005947:Glucose / Q000008:administration & dosage; D007431:Intraoperative Complications; D007552:Isotonic Solutions / Q000737:chemistry / Q000494:pharmacology; D008855:Microscopy, Electron, Scanning; D009474:Neurons / Q000187:drug effects / Q000473:pathology; D019635:Neurosurgical Procedures; D051381:Rats; D017208:Rats, Wistar; D020112:Rhodamine 123; D000077331:Ringer's Solution; D012965:Sodium Chloride / Q000009:adverse effects*; D007507:Therapeutic Irrigation; D013997:Time Factors
D005456:Fluorescent Dyes; D007552:Isotonic Solutions; D020112:Rhodamine 123; D012965:Sodium Chloride; D000077331:Ringer's Solution; D005947:Glucose