Effects of tension at the site of coaptation on recovery of sciatic nerve function after neurorrhaphy: evaluation by walking-track measurement, electrophysiology, histomorphometry, and electron probe X-ray microanalysis.
The effects of tension at the site of coaptation on recovery of sciatic nerve function after neurorrhaphy were studied by evaluating walking-track measurements, nerve conduction velocity measurements, histomorphometry, and electron probe X-ray microanalysis. Forty adult male Lewis rats underwent right sciatic nerve (SN) transection followed by one of four different nerve repair procedures (N = 10 rats per group). In Group 1, the gap was repaired by end-to-end epineural coaptation. In Group 2, a 5-mm segment of SN was resected, and the defect was repaired under high tension by epineural neurorrhaphy. In Group 3, a 5-mm segment of SN was resected, and the defect was repaired with a 5-mm interposition nerve graft. In Group 4, a 5-mm segment of SN was resected. Then, to lessen the tension that follows neurorrhaphy, an anchoring suture was added. Finally, end-to-end coaptation was performed. Walking-track analysis showed better functional recovery in Group 1 than in Group 2, and better recovery in Group 3 than in Group 2. Group 4 showed a tendency toward better recovery comparing with Group 2. Electron probe X-ray microanalysis revealed higher Na, Cl, and K peaks in axoplasm accompanied by increase in the endoneural fluid pressure (EFP) in Group 2 than those of Group 1. This higher level of Na, Cl and K may be due to impairment of axonal sodium and potassium transport mechanism in Group 2. Increase in EFP may affect nerve regeneration.
Maeda
T
T
Department of Physiology, Hyogo College of Medicine, Nishinomiya, Japan. tomooma@yo.rim.or.jp
Hori
S
S
Sasaki
S
S
Maruo
S
S
D000200:Action Potentials; D000818:Animals; D004573:Electrolytes / Q000032:analysis; D004577:Electron Probe Microanalysis; D005684:Gait; D008297:Male; D009416:Nerve Regeneration; D009431:Neural Conduction; D051381:Rats; D011917:Rats, Inbred Lew; D020127:Recovery of Function; D012584:Sciatic Nerve / Q000737:chemistry / Q000503:physiopathology / Q000601:surgery* / Q000648:ultrastructure
D004573:Electrolytes