Impact of Preoperative Ultrasound-Guided Rectus Sheath Block on Postoperative Recovery After Robot-Assisted Gynecologic Surgery: A Retrospective Cohort Study

Background/Objectives: Postoperative pain after robot-assisted gynecologic surgery delays recovery and prolongs hospitalization, yet evidence on the role of ultrasound-guided rectus sheath block (RSB) in this setting is limited. We investigated whether preoperative ultrasound-guided RSB was associated with a shorter length of hospital stay (LOS) after robot-assisted gynecologic surgery. Methods: This single-center retrospective cohort study included 266 consecutive female patients who underwent robot-assisted gynecologic surgery between November 2023 and April 2024. RSB was introduced in January 2024; 113 patients from the RSB-eligible era who received the block and 153 patients before RSB introduction served as the RSB and comparator groups, respectively. The primary outcome was LOS. Secondary outcomes included rescue intravenous fentanyl and rescue antiemetic use in the post-anesthesia care unit (PACU) and rescue analgesic administration on the general ward through postoperative day (POD) 2. Multivariable quasi-Poisson regression was used to adjust for potential confounders. Results: LOS was significantly shorter in the RSB group (median 3 [IQR 3–3] vs. 4 [3,4,5] days; p < 0.001; adjusted IRR 0.78, 95% CI 0.72–0.85). The RSB group also required less PACU rescue fentanyl (0.86 [0.68–1.38] vs. 1.17 [0.85–1.69] μg/kg; p < 0.001), fewer rescue antiemetics (3.5% vs. 11.8%; p = 0.029), and fewer ward rescue analgesics on POD 0 (52.2% vs. 68.6%; p = 0.009) and POD 1 (13.3% vs. 34.2%; p < 0.001). Conclusions: Preoperative ultrasound-guided RSB was associated with shorter LOS, reduced PACU opioid and antiemetic requirements, and fewer early ward rescue analgesics. Randomized trials are warranted to confirm these benefits.