Predictors of Prolonged Operative Time for Robotic-Assisted Laparoscopic Myomectomy: Development of a Preoperative Calculator for Total Operative Time

Abstract Study Objective To develop a preoperative calculator to predict operative time for robotic-assisted laparoscopic myomectomy (RALM). Design Retrospective cross-sectional study. Setting University medical center. Patients Women who underwent RALM performed by three high volume surgeons at a single institution from January 2014 to December 2017. Interventions Demographic characteristics, indication for surgery, surgical history, fibroid burden on imaging, and total operative time (TOT) were collected. RALM operative time was classified as 5 hours. We identified preoperative characteristics predictive of increased operative time and developed a preoperative calculator to estimate TOT. Measurements & Main Results 126 women underwent RALM during the study period, with mean operative time 213 minutes ± 66 minutes. Mean weight of total fibroids removed was 264 g ± 236 g, with mean dominant fibroid diameter 8.5 cm ± 2.6 cm. Overall, mean number of fibroids removed was 2.5 ± 2.4, and estimated blood loss was 215 ml ± 212 ml. Five patients (4.0%) received a blood transfusion and conversion to laparotomy occurred in 4 cases (3.2%). Preoperative factors significantly associated with total operative time included patient age, personal history of diabetes mellitus, uterine volume, numbers of fibroids, number of fibroids >3 cm, diameter of the dominant fibroid, and surgeon experience. Mean uterine volume for procedures with TOT 3 , compared to 461 cm 3 for procedures with TOT 3-5 hours, and 532 cm 3 for procedures with TOT >5 hours (p = 0.004). Body mass index, personal history of hypertension, previous abdominal/pelvic surgery, surgical indication, location of dominant fibroid (anterior, posterior, fundal) and classification of dominant fibroid (submucosal, intramural, subserosal, other) were not associated with TOT. Our preoperative calculator correctly predicted TOT category in 88% of patients, and estimated operative time within a one-hour margin in 80% of patients. Conclusions Robotic-assisted laparoscopic myomectomy has become a more common surgical approach for the management of uterine fibroids. Preoperative radiographic evaluation and a thorough understanding of patients’ histories may enhance patient counseling and surgical planning. Uterine volume, fibroid number and fibroid size appear more predictive of operative time than fibroid location.