The influence on resection line during supracervical hysterectomy: physiological extension of endometrial cells in the cervix uteri

Objective: A straight resection of corpus uteri using the sacrouterine ligament as landmark is a common method during supracervical hysterectomy. Subsequent spotting rates of up to 25% suggest the existence of residual endometrial glands in the remaining cervical tissue, casting doubt on the landmark qualities of the sacrouterine ligament. Fifty-one females who underwent total laparoscopic hysterectomy for benign diseases were investigated. Material and Methods: Macroscopic uterine parameters were determined during operation. First appearance of endometrium cells, complete disappearance of endometrial cells in the cervix and others were measured microscopically with reference to the external cervical orifice. Associations were described using odds ratio with 95% confidence interval and p-value <0.05. Results: The region of the cervix, in which exclusively cervical glands are found, is relatively small but varies considerably around the mean (mean, 23.3 mm, range, 10 to 35 mm). In this cohort in a remnant cervical stump of 23 mm length, endometrial glands would be found in 51%. There was no correlation between full cervical length and uterine parameters but smaller uteri tended to be associated with deeper endometrial penetration. Conclusion: There is a discrepancy between common definition and histological findings concerning the cervix uteri. Our findings indicate that the sacral uterine ligament is not suitable as an anatomic landmark for the laparoscopic supracervical hysterectomy operation. Regarding the distribution pattern of endometrial glands in the isthmic zone, a deep conical excision seems to better prevent subsequent spotting than a straight resection with thermocoagulation of the remaining cervical canal.