Objectives: To compare postoperative urinary retention and pain control when bupivacaine versus saline for hydrodissection is used while placing tension-free vaginal tape midurethral slings.
Methods: A prospective, randomized, double-blind trial was performed after institutional review board approval. Sixty women were randomized to receive bupivacaine or saline for hydrodissection. Subjects and research team were blinded to subject assignments. Group characteristics were compared using the Student t test, the χ2 test, and the Mann-Whitney U test. Proportions of subjects with a successful postoperative voiding trial along with measurements of postoperative pain and analgesic use were compared using similar appropriate tests. The study was powered to detect differences in voiding trial success from an estimated 58% to greater than 90% with P < 0.05 and 0.8 power using 25 subjects per group.
Results: Thirty patients were allocated to each group. One subject in the saline-only group was excluded. Group characteristics were not different. After surgery, pain medication use (20/30 vs 25/29 for bupivacaine vs saline only; P = 0.08), pain scores (36 ± 22 vs 31 ± 24; P = 0.49), and successful voiding trials did not differ (14/30 vs 19/29; P = 0.14), whereas postvoid residuals did differ (225 ± 180 mL vs 140 ± 147 mL; P = 0.043).
Conclusions: Bupivacaine was not seen to improve immediate postoperative pain after placement of a tension-free vaginal tape. It did not increase the risk of failing a postoperative voiding trial. Without an obvious benefit, the use of an additional medicine is not supported. We suggest saline alone be used for hydrodissection.