Identifying key predictors for uterine manipulator use in robotic simple hysterectomy: a retrospective cohort analysis.

Background: Robotic simple hysterectomy (RSH) is the most common robotic gynecologic surgery in the United States. Uterine manipulators are commonly used to handle the uterus during laparoscopic surgery, but few studies have examined their necessity in RSH. This study retrospectively compares RSH cases with and without the use of manipulators, and identifies predictors for their intraoperative use. Materials and methods: This retrospective cohort study included patients undergoing RSH for benign pathologies at Kawasaki Medical School from October 2020 to December 2022. Patients with malignancies were excluded. The robotic surgeries were performed by three skilled surgeons using the four-arm da Vinci Xi surgical system. Data on perioperative and operative parameters were collected, including age, body mass index (BMI), history of abdominal surgery, disease type, presence of ovarian cysts, and operative time. Statistical analyses were performed using EZR software, with multivariate logistic regression to identify predictive factors for uterine manipulator use. Results: The study included 113 patients who underwent RSH without a uterine manipulator and 58 with one. Patients without a manipulator were older, while those with a manipulator had higher BMIs and a higher prevalence of ovarian chocolate cysts and Douglas obliteration. Operating time was shorter without a manipulator. Independent predictors for manipulator use were higher BMI, presence of ovarian endometrioid cysts, and Douglas obliteration. Conclusion: RSH without a uterine manipulator is feasible and can reduce the need for surgical assistants. Predictors for manipulator use include higher BMI, ovarian cysts, and Douglas obliteration. The use of a fourth robotic arm can enhance surgical independence and resource efficiency. Further research is needed to assess the long-term cost-effectiveness and outcomes of this approach.