Pelvic neural injuries and acute voiding changes in rat models of radical hysterectomy

by Miaomiao Liu, Lin Qian, Haibin Wei, Jing Zhang, Ting Wang, Yanpeng Wang

Objective

To establish experimental models of radical hysterectomy based on Querleu-Morrow classification, and clarify the quantitative evaluation of pelvic neural injuries and acute voiding changes postoperatively.

Methods

Female Sprague Dawley rats were randomized and received sham operation, type A, B1, C1 and C2 radical hysterectomies (as the injury gradually increased), respectively. The excised specimens were collected for hematoxylin and eosin staining and Pgp9.5 (pan-neuronal marker) immunohistochemistry to evaluate the facial and neural resection of paracervix. At 21 days after operation, 5 rats in each group were used for urine spot test, awake cystometry and leak point pressure test, and the other 5 ones were used for hematoxylin and eosin staining of bladder and pelvic neural plane, and Masson’s trichrome staining of bladder.

Results

Paracervical Pgp9.5 immunohistochemistry revealed that the resected neural area in C2 group was significantly larger than that in type A, B1, and C1 groups. Compared with type A and B1 groups, the excised paracervical facial area was significant higher in type C1 and C2 groups. The occurrence of urinary retention was 0%, 10%, 40% and 100% in type A, B1, C1 and C2 groups, respectively, which was further confirmed by average residual volume. The incidence of neurogenic bladder and its severity gradually increased from type A to type C2 groups, consistent with the findings of leakage point pressure, bladder size, bladder weight, pathological changes and collagen deposition. Neuropathological evaluation revealed neural injuries involved the main components of pelvic neural plane.

Conclusion

The novel rat models of radical hysterectomy based on Querleu-Morrow classification revealed the structural and functional changes of voiding after operation, which reflected the situation in humans.