Over the past 4 decades there has been increasing use of minimally invasive surgery (MIS) for gynecologic cancer, particularly endometrial and cervical cancers. Uterine manipulators are a device inserted into the uterine cavity during MIS approaches to aid in directing the uterus within the pelvis, facilitating access to the uterine blood supply, defining the cardinal ligaments, lateralizing the ureters, and delineating the cervicovaginal junction. However, concerns have been raised regarding whether these devices are safe to use when the uterine corpus or cervix contains cancer.
In 2018, the LACC trial was published and demonstrated decreased survival for patients with cervical cancer who had undergone radical hysterectomy via a minimally invasive route.1 Several hypotheses were proposed to explain this finding including possible tumor disruption from use of a uterine manipulator. Regrettably, this study did not document manipulator use, and therefore its influence on outcomes could not be measured. However, since that time there has been honed interest into the potential negative influence of uterine manipulators on endometrial and cervical cancer surgery.
Uterine manipulators typically are inserted through the uterine cervix and reside in the endometrial cavity. It is often an inflated balloon which stabilizes the device within the cavity. Hypotheses for how they may contribute to the spread of malignancy include the massage of endometrial tumor from the pressure of the inflated balloon, facilitation of tumor dissemination through cervical lymphatics or vasculature as the manipulator traverses or punctures a cervical cancer, and possibly perforation of the uterine cavity during placement of the manipulator, and in doing so, contaminating the peritoneal cavity with endometrial or cervical cancer cells that have been dragged through with the device.
Interestingly, uterine manipulator placement is not the only time during which endometrial or cervical cancers may be disturbed prior to resection. Many diagnostic procedures such as cervical excisional procedures (loop electrosurgical excision procedure and conizations) or hysteroscopic resections cause significant intentional disruption of tumor. In the case of hysteroscopy for endometrial cancer, endometrial cancer cells have been detected in the peritoneal washings of endometrial cancer patients who have undergone this procedure, however, no worse outcomes have been associated when hysteroscopy was included as part of the diagnostic work-up, suggesting that more than simply efflux into the peritoneal cavity is necessary for those tumor cells to have metastatic potential.2
Indeed the data is mixed regarding oncologic outcomes with uterine manipulator use, especially for endometrial cancer. In one recent study the outcomes of 951 patients with endometrial cancer from seven Italian centers were evaluated.3 There was no difference in recurrence rates or disease-specific survival between the 579 patients in whom manipulators were used and the 372 patients in which surgery was performed without manipulators. More recently a Spanish study reported retrospectively on 2,661 patients at 15 centers and determined that use of a uterine manipulator (two-thirds of the cohort) was associated with a hazard ratio of 1.74 (95% confidence interval, 1.07-2.83) for risk of death.4 Unfortunately, in this study there were substantial differences between sites that used manipulators and those that did not. Additionally, while one would expect different patterns of recurrence if the manipulator was introducing a unique mechanism for metastasis, this was not observed between the manipulator and nonmanipulator arms. Finally, the groups were intrinsically different with respect to important risk factors such as lymphovascular space invasion, which might have contributed to the observed outcomes. It is important to recognize that, in both the LAP-2 and LACE trials, minimally invasive hysterectomy for endometrial cancer had been shown to have noninferior survival outcomes, compared with open hysterectomy.5,6 While these large randomized, controlled trials did not capture uterine manipulator usage, presumably it was utilized in at least some or most cases, and without apparent significant negative effect.
In cervical cancer, there is more competing data raising concern regarding manipulator use. The SUCCOR study was completed in 2020 and included a retrospective evaluation of 1,272 patients who had undergone open or MIS radical hysterectomy for early stage cervical cancer across 126 European centers during 2013-2014.7 They were able to evaluate for variables, such as uterine manipulator use. While they found that recurrence was higher for patients who had MIS hysterectomy, the HR (2.07) was similar to the HR for recurrence (2.76) among those who had uterine manipulator use. Conversely, the hazard ratio for recurrence following MIS radical hysterectomy without a manipulator was comparable with the superior rates seen with open surgery. This study was retrospective and therefore is largely hypothesis generating, however it does raise the question of whether the technique of MIS radical hysterectomy can be performed safely if particular steps, such as avoidance of a uterine manipulator, are followed. We await definitive results from prospective trials to determine this.
As mentioned earlier, the uterine manipulator is an important safety and feasibility tool for MIS hysterectomy. When not utilized, surgeons may need to add additional ports and instrumentation to maneuver the uterus and may have difficulty completing hysterectomy via a MIS approach for obese patients. There are additional urologic safety concerns when uterine elevation and cervicovaginal delineation is missing. Therefore,While the wealth of prospective data suggests that manipulators are most likely safe in hysterectomy for endometrial cancer, they should be avoided if a minimally invasive approach to cervical cancer is employed.
Dr. Rossi is assistant professor in the division of gynecologic oncology at the University of North Carolina at Chapel Hill. She has no conflicts of interest to report. Email her at [email protected].