Preemptive Infiltration of Local Anesthetics During Vaginal Hysterectomy: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Undergoing pelvic floor reconstructive surgery bears a lifetime risk between 14% and 19%, with a significantly higher risk in elderly and postmenopausal women. The traditional preferred surgical approach for pelvic floor disorders (PFDs) is vaginal hysterectomy (VH) with or without pelvic floor repair. Uterine pathology treatments via hysterectomy for women, including premalignant conditions and fibroids, typically opt for the VH route. A shorter recovery time and faster return to daily activities have been associated with VH, as this procedure leaves no large abdominal incision (which may produce further wound-related complications and higher levels of pain during the recovery process). A proposed preemptive anesthetic modality aimed at minimizing postoperative pain (as well as narcotic and opioid consumption) is the application of infiltration of local anesthetics during pelvic floor reconstructive surgeries. This study aimed to evaluate infiltration of local anesthetics and their impact on perioperative outcomes for women, as well as postoperative pain for patients undergoing VH for the surgical management of PFDs. Abstract selection took place via 3 authors (A.P., A.D., and D.Z.), who used the following meta-analysis inclusion criteria: randomized controlled trials (RCTs) comparing outcomes of patients undergoing VH due to PFDs and/or other benign indications (ie, fibroids, uterine bleeding, precancerous conditions) and received either intraoperative infiltration with local analgesic or not. Comparator groups consisted of VH-eligible patients who received placebo injections of normal saline solution in place of local anesthetic. Main outcomes of the study were postoperative pain scores and opioid use. Excluded studies were any case reports, nonrandomized trials, or animal studies. The databases searched for articles published up to January 2022 included MEDLINE (1966-2022), Scopus (2004-2022), Cochrane CENTRAL Register of Controlled Trials, and ClinicalTrials.gov databases. Authors retrieved the full text of those studies deemed to meet the criteria. Overall, 5 RCTs were included in the analysis. Their data included 277 women who underwent a VH, with the local analgesia (LA) group patients, or those receiving preemptive local infiltration analgesia, consisting of 139 patients, whereas the control group (patients in the non-LA group who received no preemptive LA) included 138 patients. The main analgesic regimen was 0.5% bupivacaine with 1:200,000 epinephrine followed by 0.5% ropivacaine. Total anesthetic injection amounts ranged from 20 to 50 mL from study to study. In addition, injection sites exhibited variation, but the uterosacral ligaments were the most prevalent sites of local analgesic injection. Also, opioid-based consumption up to 24 hours postoperatively was significantly reduced in the LA group when compared with the non-LA group (197 patients). Overall, the average postoperative scores at both 30 minutes to 2 hours and 3 to 6 hours postoperatively were significantly lower in the LA group when compared with the non-LA group. Despite this, the postoperative pain scores later up to 24 hours postoperatively did not differ between groups. A major strength of the study was the authors' choice to set aside data restrictions to eliminate data losses. This study is the first to present outcomes from existing RCTs of local infiltration analgesia use before surgical incision during VH. Limitations of the study include a limited number of existing studies from which data were pulled, thereby hindering the ability to draw safe conclusions. The relatively small level of evidence could hinder accurate summaries of local anesthetic effects, with the possibility of overestimation/underestimation on the identified effects. The authors included some studies that were not yet published at the time of review. An additional weakness was the variation of the methodological quality of recruited studies due to design differences, included populations, and methodology. Significant heterogeneity was detected in areas such as analgesic regimens utilized, injected dosage, injection locations, and indication for surgery. Preemptive application of LA in patients undergoing VH for PFDs appears as a safe and beneficial use of anesthetic in terms of hospital stay, opioid use, and short-term postoperative pain. However, additional studies would be required to identify dosages, the optimal anesthetic regimen, and application sites to achieve the peak postoperative benefit.