| Objective:1.The aim of this study was to improve the traditional optical fiber used in PLDD,which has the ability to lock the laser energy and vaporize the nucleus pulposus tissue efficiently.2.To compare the effects of the traditional optical fiber and modified optical fiber on ablation of porcine intervertebral disc nucleus pulposus.3.To observe the therapeutic effect of the modified optical fiber on the patients diagnosed as prolapse of lumbar intervertebral disc.Methods:1.On the basis of the traditional optical fiber,we change the shape of the optical fiber front end,so the laser energy can be gathered in the head end of the optical fiber.2.In animal experiment,sixty fresh spine units from the 12-month porcine were randomly divided into the traditional optical fiber group(A group)and the modified optical fiber group(B group),and each group was divided into three subgroups according to the different energy(n = 10).A1 group and B1 group,A2 group and B2 group,A3 group and B3 group were performed ablation with 200 J,400J,and 600 J,respectively.After the C-arm machine guided puncture,the ablation was performed according to the mentioned energies and the T2 values in every group before and after the operation were measured by magnetic resonance imaging.Then,the specimens were kept at-20 ℃ for 24 h,and an incision in the median of intervertebral space and parallel to the upper and lower vertebral body was made to measure the length and width of vaporization cavity.3.In clinical study,thirty-four patients diagnosed as prolapse of lumbar intervertebral disc in the Affiliated Hospital of Qingdao University underwent PLDD by the modified optical fiber,and MRI images were recorded before operation,immediately after operation,1 month and 3 months after operation.The MRI T2 values,intervertebral height changes,patient’s symptoms and signs,VAS,improved MacNab standard and ODI were also recorded.Results:1.We made a modified optical fiber based on the traditional optical fiber successfully.2.In animal experiment,the T2 values of nucleus pulposus before the operation were 704.2 ± 22.6 in the B1 group,709.3 ± 31.6 in the B2 group,681.1 ± 91.7 in the B3 group,724.3 ± 21.2 in the A1 group,702.2 ± 26.4 in the A2 group,and 726.8 ± 21.4 in the A3 group.The T2 values of nucleus pulposus after the operation in the B1,B2,B3,A1,A2,and A3 groups were 204.2 ± 11.1,90.0 ± 3.5,91.7 ± 4.8,443.5 ± 20.1,200.4 ± 6.8,and 92.3 ± 4.0,respectively.There were significant differences of T2 values before and after operation in a same group(P<0.05).The vaporization cavity length(2.323 ± 0.094cm)and width(1.236 ± 0.043 cm)of B1 group were higher than those of A1 group(0.203± 0.070 cm,0.204 ± 0.043 cm),and the difference was statistically significant(P < 0.05).The vaporization cavity length(2.862 ± 0.048 cm)and width(1.506 ± 0.117 cm)of B2 group were higher than those of A2 group(2.276 ± 0.048 cm,1.232 ± 0.041 cm),and the difference was statistically significant(P < 0.05).The vaporization cavity length(2.860 ±0.054 cm)and width(1.495 ± 0.105 cm)of B3 group were lower than those of A3 group(4.215 ± 0.246 cm,3.226 ± 0.141 cm),and the difference was statistically significant(P <0.05).The vaporization cavity in the B2 group was bigger than the B1 group(P < 0.05),but there was no significant difference between the B2 and B3 groups.3.In clinical study,the laser energy emitted by the modified optical fiber was concentrated,and the needed energy was less,which could be more close to the target to work.The application of the modified optical fiber during the PLDD improve the clinical symptoms and signs of patients with prolapsed of lumbar intervertebral disc significantly,the excellent rate of up to 82% at 1 month after operation and 85% at 3 month after operation.the intervertebral height had no significant changes(P>0.05).The T2 value at immediately after operation was lower than that before the operation(P<0.05).The VAS and ODI at immediately after operation,1 month and 3 months after operation were significantly lower than that before the operation(P<0.05).Conclusion:1.The improved optical fiber meets our expectations,and the modified optical fiber could lock the laser energy better.2.Comparing to traditional optical fiber,modified optical fiber can ablate the nucleus pulposus tissue accurately.3.PLDD with modified optical fiber has higher safety,accurate curative effect. |
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