Does contained manual morcellation in minimally invasive hysterectomy prevent myometrial cell spillage? Evidence from sequential pelvic washings

Background Concerns regarding tissue dissemination during morcellation have led to the adoption of containment systems during minimally invasive hysterectomy. However, the timing and extent of potential myometrial cell spillage during contained manual morcellation remain unclear. Objective To evaluate the presence and timing of myometrial cell spillage during minimally invasive hysterectomy with contained sharp morcellation using sequential pelvic washings. Study Design This was a prospective single-center observational study of premenopausal patients undergoing minimally invasive hysterectomy for presumed benign large fibroid uteri requiring contained manual morcellation. Three sequential pelvic washings were collected: baseline after peritoneal entry, posthysterectomy before morcellation, and postmorcellation. Cytologic evaluation with Romanowsky staining and immunohistochemical confirmation with Caldesmon was performed by a blinded pathologist. The primary outcome was detection of myometrial cells; secondary outcomes included timing of detection and associations with clinical variables. Results Fifty premenopausal patients were included. Myometrial cells were identified in 4 of 50 patients (8%; 95% confidence interval, 2%–19%), and always in only one of the 3 sequential washings. Baseline washings were negative in 98% of cases. Myometrial cells were detected in 4% of posthysterectomy before morcellation and in 2% of postmorcellation samples. All detections were confirmed with Caldesmon immunohistochemistry. Mesothelial cells were present in all washings, confirming sampling adequacy. Final pathology revealed benign disease in all patients. Conclusion Sequential pelvic washings demonstrate that contained manual morcellation is associated with a low rate of myometrial cell spillage, with most spillage occurring before morcellation begins. These findings support the safety and effectiveness of containment systems and highlight that tissue dissemination risk may originate from the hysterectomy itself rather than morcellation alone.