Use of Historical Surgical Times to Predict Duration of Hysterectomy: Stratifying by Uterine Weight.

STUDY OBJECTIVE: To describe the accuracy of historical averages for estimating OR (operating room) time for hysterectomy among women with small and large uteri.

DESIGN (CANADIAN TASK FORCE CLASSIFICATION): A retrospective cohort study Design Classification: Canadian Task Force Classification II-2 SETTING: Data from women who underwent abdominal, vaginal, or laparoscopic hysterectomy between 2015 and 2017 at University of North Carolina Hospitals were analyzed. Historical and actual OR times were compared using linear regression. Patient characteristics were also evaluated to determine whether they were associated with the accuracy of predicted OR times.

PATIENTS: Nine hundred and eighty-five adult women (≥18 years old) who underwent surgery for benign indications or for suspected but not biopsy confirmed malignancy were included.

INTERVENTIONS: Not applicable.

MEASUREMENTS AND MAIN RESULTS: Historical averages overestimated OR time by a median 14 minutes (IQR -29 - 49). The OR time in women with small uteri (<250g) was significantly more likely to be overestimated than women with large uteri (≥250g) (median time 21 minutes [IQR -16 - 52] and 3 minutes [IQR -38 - 44], respectively), p<0.001. In TLH and LAVH, women with uteri ≥250g took significantly longer than hysterectomy for women with uteri <250g (36 minutes [95% CI 24 - 50] and 95 [95% CI 12 - 179] minutes longer, respectively), p<.001 and p=0.03.

CONCLUSION: Using historical averages overestimates OR time, and it is more pronounced in women with small uteri. However, there is a relatively large range of OR times, even among women with the same size uteri. This study highlights the importance of preoperative planning, and in cases where endometriosis is expected, manually adding time to estimates is recommended.