title: Intradiscal pressure after repeat intradiscal injection of hypertonic saline: an experimental study.
abstract: Chemonucleolysis with chymopapain is an effective alternative to an operation for the treatment of some patients who have a lumbar intervertebral disc herniation. However, chymopapain is associated with rare but serious complications. Accordingly, alternative substances for chemonucleolysis have been sought. The main beneficial effect of chemonucleolysis derives from the decrease in the intradiscal pressure. We have previously reported that hypertonic saline injected into the intervertebral discs decreased the intradiscal pressure, but only temporarily. The present experimental study investigated changes in the intradiscal pressure after a repeat intradiscal injection of hypertonic saline. The lumbar intervertebral discs of 18 living rabbits were examined: 10% hypertonic saline was injected intradiscally just once in 12 rabbits, and the same dosage was injected again, 4 weeks later, in the same animals. The intradiscal pressure was measured at 1, 4, 8, and 12 weeks after the second injection. The remaining six rabbits were used as controls, without puncture and without injection. The intradiscal pressure of the group with repeat hypertonic saline injection at 4 weeks was significantly lower than that of the control group. The decreased pressure showed a tendency to increase at 8 weeks, and it had recovered at 12 weeks. The results of this study suggest that repeat hypertonic saline injections may be clinically useful.
authors.affiliation: Department of Orthopaedic Surgery, Kurume University School of Medicine, Japan. spine@med.kurume-u.ac.jp
authors.forename: Kimiaki
authors.initials: K
authors.lastname: Sato
authors.forename: Kensei
authors.initials: K
authors.lastname: Nagata
authors.forename: Teruyuki
authors.initials: T
authors.lastname: Hirohashi
mesh_terms: D000818:Animals; D007403:Intervertebral Disc / Q000166:cytology / Q000502:physiology*; D007404:Intervertebral Disc Chemolysis; D008297:Male; D023421:Models, Animal; D011312:Pressure; D011817:Rabbits; D012462:Saline Solution, Hypertonic / Q000494:pharmacology*
chemical_list: D012462:Saline Solution, Hypertonic