Objective: To compare the traumatic responses following microendoscopic discectomy (MED) and open discectomy.
Methods: Forty-four patients with single level lumbar disk herniation underwent MED (Group A, n = 22) or open discectomy (Group B, n = 22). The intra-operational blood loss, duration of operation, intra-operative blood loss, and post-operational hospital stay were noted and the pain severity of incision was evaluated by visual analog scale (VAS). Serum levels of IL-6, C-reactive protein (CRP) and creatine kinase (CK) were measured before operation and 24 h and 48 h after operation. The clinical outcomes were evaluated by Oswestry disability index (ODI) before operation and 6 months after operation.
Results: The intra-operative blood loss of Group A was 47.50 +/- 11.62 ml, significantly less than that of Group B (129.11 +/- 71.75 ml, P < 0.01), the duration of operation of Group A was 64.77 +/- 17.83, significantly shorter than that of Group B (78.18 +/- 24.32, P < 0.05). The postoperative hospital stay of Group A was 6.09 +/- 2.22 days, significantly shorter than that of Group B (8.73 +/- 3.53, P < 0.01). The scores of VAS 1, 2, and 3 days after the operation were all significantly lower than those of Group B (all P < 0.001). The rate of remarkable symptomatic improvement of Group A was 94.7%, not significantly different from that of Group B (94.4%, P > 0.05) The serum IL-6 showed no significant difference between these 2 groups pre-operationally, and peaked 24 h after operation and decreased 48 h after operation in both groups, returning to the pre-operational level in Group A. The IL-6 level 24 h and 48 h post-operationally of Group A was 31.6 +/- 9.88 pg/ml and 26.25 +/- 9.30 pg/ml respectively, both significantly lower than those of Group B (39.16 +/- 11.14 pg/ml and 32.55 +/- 8.83 pg/ml respectively, both P < 0.05) The serum CK showed no significant difference between these 2 groups pre-operationally, and peaked 24 h after operation and decreased 48 h after operation, but still higher than those before operation, in both groups. The serum CK 24 h and 48 h after operation of Group A were 167.91 +/- 51.85 and 131.50 +/- 52.70 U/L respectively, both significantly lower than those of Group B (401.55 +/- 108.86 and 260.32 +/- 64.98 U/L, both P < 0.01). The serum CRP level showed no significant difference between these 2 groups pre-operationally, and increased post-operationally, peaked 24 h after operation and then decreased in Group A, however, continued to increase in Group B. The serum levels of CRP 24 h and 48 h post-operationally of Group A were 12.68 +/- 7.10 and 10.77 +/- 5.25 pg/ml, both significantly lower than those of Group B (20.82 +/- 8.79 and 29.95 +/- 14.85 pg/ml, both P < 0.01). The clinical outcomes 6 months after operation of these two groups were all satisfying.
Conclusion: Both MED and open discectomy show good clinical outcomes in treatment of single level lumbar disk herniation, however, the less responses of serum IL-6, CRP, and CK show that the MED procedure is less traumatic.