The effect of low-dose external beam radiation on extraneural scarring after peripheral nerve surgery in rats.
OBJECTIVE
Scar tissue is an inevitable result of peripheral nerve surgery. A variety of substances have been used to prevent epineurial scarring. In this study, the effect of low-dose radiation therapy on epineurial scarring was investigated.


METHODS
Seventy-eight male Sprague-Dawley rats were studied. A total of 60 rats were subjected to one of three types of surgical procedure on the sciatic nerve, as follows: Procedure 1, external neurolysis (n = 20); Procedure 2, abrasive injury (n = 20); and Procedure 3, anastomosis (n = 20). On the left sciatic nerves, 700 cGy external beam radiation was administered 24 hours after surgery, and the right sciatic nerves served as a control group (surgery only). Eighteen animals without surgical intervention were used to establish the fibrotic effect of radiotherapy on normal nerves. A neurological examination was performed weekly. Six weeks after surgery, the extent of extraneural scarring was examined by gross microdissection by means of a numerical grading scheme and histological analysis. Cellular density and surface measurements of scar tissue were also evaluated.


RESULTS
The dissection around the nerve was easier in rats treated with low-dose radiation compared with the control group. Furthermore, grading scores in both nerve adherence and nerve separability were significantly lower in treated nerves than in the control group (P < or = 0.05). Low-dose radiotherapy decreased the scores of cellular density and surface measurement of scar tissue (P < or = 0.05). In normal nerves, radiotherapy did not produce any fibrotic effects and the density of fibroblasts/fibrocytes was also very low.


CONCLUSIONS
In the case of surgery or local trauma to peripheral nerve, the use of low-dose radiation therapy may be a safe method of limiting postoperative epineurial scar formation.
Görgülü
Aşkin
A
Department of Neurosurgery, School of Medicine, University of Suleyman Demirel, Isparta, Turkey. askingorgulu@hotmail.com
Uzal
Cem
C
Doğanay
Latife
L
Imer
Murat
M
Eliuz
Kenan
K
Cobanoğlu
Sabahattin
S
D000818:Animals; D002921:Cicatrix / Q000209:etiology* / Q000473:pathology / Q000517:prevention & control*; D004195:Disease Models, Animal; D005355:Fibrosis / Q000209:etiology / Q000517:prevention & control; D008297:Male; D019635:Neurosurgical Procedures / Q000009:adverse effects*; D011879:Radiotherapy Dosage; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000293:injuries / Q000528:radiation effects* / Q000601:surgery*; D014945:Wound Healing / Q000528:radiation effects