Shear wave elastography for quantitative assessment of nerve tissue stiffness after sciatic nerve decompression in diabetic rats
Dian-Cheng Li1, Wen-Xue Li1, Yu-Wei Xin1
1Department of Ultrasound, Peking University People's Hospital, Beijing, China.
Introduction:
Diabetic peripheral neuropathy (DPN) is a common complication of diabetes mellitus. Surgical decompression of distal DPN has been shown to reduce ulceration and amputation rates, though recurrence risk persists, warranting postoperative follow-up. Current DPN evaluation relies on clinical symptoms, signs, and nerve conduction studies (NCS), which have inherent limitations. Shear wave elastography (SWE) is a non-invasive, cost-effective technique that quantifies tissue stiffness and reflects underlying pathology, and has been reported as a potential tool for early detection of diabetic neuropathy. This study aimed to assess the value of SWE for quantitative evaluation of nerve stiffness after sciatic nerve decompression in diabetic rats, providing a preliminary theoretical basis for future clinical research.
Methods:
A total of 24 male Sprague-Dawley (SD) rats were used in this study. Six served as normal controls (n = 6). The remaining 18 underwent sciatic nerve compression to establish a diabetic neuropathy model. Four weeks later, 6 of these were assigned to the diabetic sciatic nerve compression 4-week group (DSNC, n = 6), while the other 12 received surgical decompression and were further divided into 2-week (DSND2, n = 6) and 8-week (DSND8, n = 6) post-decompression groups. Nerve stiffness was assessed by SWE, alongside motor nerve conduction velocity (MNCV) and histopathological examination.
Results:
In the DSND2 group, sciatic nerve stiffness was significantly decreased compared with the DSNC group (p < 0.01), with a further decrease in the DSND8 group (p < 0.05 vs. DSND2). No significant differences in MNCV, myelinated fiber density, myelin sheath thickness, or average axon diameter were found between the DSND2 and DSNC groups (p > 0.05). In contrast, the DSND8 group showed significant improvements in all these parameters versus the DSNC group (p < 0.05), with MNCV reaching 49.17 ± 4.71 m/s. Moreover, myelinated fiber density and myelin sheath thickness were also significantly higher in the DSND8 group than in the DSND2 group (p < 0.05).
Conclusion:
Dynamic SWE assessment of decreased neural stiffness after sciatic nerve decompression predicts functional improvement in diabetic rats, and may serve as a noninvasive evaluation method.
