Preoperative pelvic floor muscle injections and pudendal nerve blocks with bupivacaine and dexamethasone do not significantly improve pain control after vaginal apical prolapse repair, compared with placebo, according to a study.

In a randomized trial, patients generally reported mild postoperative pain and low dosages of narcotic use. “The majority reported that they returned to their baseline activity by 2 weeks after surgery, which should be reassuring to similar urogynecology patient populations,” said Lauren Giugale, MD.

Although many gynecologic surgeries increasingly are performed as outpatient procedures, patients may have inadequate pain control and persistently use narcotics after surgery. In an effort to reduce postoperative pain, doctors have tried preemptive analgesia with various local anesthetic techniques. These approaches have had mixed results, however, and there is “no consensus on the ideal local anesthetic technique to reduce postoperative pain after vaginal reconstructive surgery,” said Dr. Giugale, of the University of Pittsburgh.

To evaluate whether preoperative pelvic floor muscle injections and pudendal nerve blocks with bupivacaine and dexamethasone improve postoperative pain control after vaginal apical prolapse repairs, Dr. Giugale and colleagues conducted a three-arm, double-blind trial that included 75 patients. Patients received placebo (normal saline), bupivacaine alone, or bupivacaine combined with 4 mg of dexamethasone at four injection sites.

Dr. Giugale presented the study results at the virtual annual scientific meeting of the Society of Gynecologic Surgeons.

A range of procedures

Participants received bilateral levator ani muscle injections via a transobturator approach and pudendal nerve blocks via a transvaginal approach. They received the injections – 5 mL at each site – after the administration of general anesthesia but before the start of surgery. “Anecdotally, we have had good success” with the transobturator approach to treating chronic pelvic pain, which was part of the rationale for the trial, said Dr. Giugale.

The study included women 18 years or older who were scheduled for a vaginal native tissue repair with apical support. Participants had to be able to tolerate general anesthesia with a standardized enhanced recovery after surgery (ERAS) protocol. The investigators excluded women undergoing mesh-augmented prolapse repairs or abdominal surgery and those with chronic pelvic pain or immunosuppression.

Each treatment arm had 25 patients. Patients had an average age of 69 years and an average body mass index of 27.5 kg/m2. Most patients were white, and demographic variables did not significantly differ among the groups.

“The distribution of prolapse procedures was similar among study groups, with colpocleisis being the most common, followed by uterosacral ligament suspension, levator myorrhaphy, and sacrospinous ligament fixation,” said Dr. Giugale. Rates of concomitant hysterectomy were similar for each group.

Before surgery, patients completed pain, nausea, and activities assessments. At 6 hours after surgery, they completed pain and nausea assessments. During postoperative days 1 through 3, patients documented pain scores and analgesic use. One week after surgery, patients completed pain and activities assessments. And at postoperative weeks 2, 6, and 12, they completed additional activities assessments. The assessments included validated handouts that patients completed at home, and no additional office visits were required.

The numeric rating scale pain score on the day after surgery was the primary outcome, and the median pain score did not significantly differ among the groups (3.75 in the placebo group, 4 in the bupivacaine group, and 3 in the bupivacaine plus dexamethasone group). Between-group differences in pain scores at other time points also were not significant.

Activities assessments, nausea and vomiting scores, the percentage of patients with same-day discharge, urinary retention, postoperative narcotic use as measured by oral morphine equivalents, and adverse events also did not significantly differ among the groups.

“One week after surgery, 52% of women reported that they were at or better than their baseline preoperative activity level, which increased to 70% at 2 weeks, 84% at 6 weeks, and 94% at 12 weeks,” Dr. Giugale said.

In all, 57% of patients used narcotic medicine the day after surgery, which decreased to 44% on day 3. The dosage was low, with a median oral morphine equivalent of 5 mg of oxycodone or less per day, she said.

Early postoperative pain may be influenced by procedure type, according to an exploratory analysis. Through the first postoperative day, “there was a trend toward more pain with uterosacral ligament suspension,” Dr. Giugale said. By day 3, sacrospinous ligament fixation was associated with significantly more postoperative pain.

The role of ERAS protocols

The heterogeneity of surgical procedures among the treatment groups and the use of a predefined ERAS protocol may have confounded the results. In addition, the researchers did not measure patient satisfaction, and the findings may not apply to different patient populations, Dr. Giugale noted.

“As more and more gynecologic surgery patients have surgery under these enhanced recovery protocols, maybe additional preemptive local analgesia for vaginal reconstructive surgery is not all that beneficial,” she said. “Maybe we are getting enough benefit from the enhanced [recovery] protocols themselves.”

The investigators studied a novel idea – dual local therapy for pain in patients undergoing pelvic floor surgery – and described a novel transobturator technique for levator injection, commented Sunil Balgobin, MD, associate director of the female pelvic medicine and reconstructive surgery fellowship at University of Texas Southwestern Medical Center, Dallas.

“For the current opioid problem, development of alternative pain control strategies is extremely important to reduce narcotic use and improve patient outcomes,” Dr. Balgobin said. The study “addresses an important gap in the literature, is relevant to surgeons performing vaginal apical procedures, and aims to advance research in this area for the potential benefit of ... patients.”

Interpretation of the results for individual procedure types may be limited by the smaller sample sizes, he added.

The researchers and Dr. Balgobin had no relevant financial disclosures.

SOURCE: Giugale L et al. SGS 2020, Abstract 10.