We present here an analysis of 381 women who underwent LEEP using a right-angled triangular loop combined with CC for CIN confirmed preoperatively by colposcopically directed biopsy. This study found a low rate of residual disease (0.8%), despite the fact this procedure showed a positive RM rate of 14.7%. Of note, CIN1/2/3 and AIS cases showed a low rate of only 0.3% (1/365) with residual disease. During the follow-up period, recurrent disease occurred in 1.1% of cases (4/365, 1 with positive RM and 3 with negative RM). Based on these results, we suggest that positive RM cases with a final diagnosis of CIN or AIS and who undergo LEEP with CC can be followed up by pap, HPV DNA testing and ECC without re-excision or hysterectomy. However, the present study indicates that patients diagnosed as having microinvasive SCC with positive RMs following LEEP with CC may have a higher rate of residual disease (15.4%, 2/13) than CIN/ AIS cases. Moreover, 2 cases were reported as invasive SCC and microinvasive SCC after hysterectomy. In spite that 3 microinvasive SCC cases without additional treatment (1 with positive RM, 2 with negative RMs) revealed no residual/recurrent disease during follow-up, we suggest that microinvasive SCC cases with negative RM who undergo LEEP with CC can be followed up without additional surgical treatment.
The present study showed a positive RM frequency of 14.5%, which was similar to previous studies using LEEP. However, residual/recurrent diseases were diagnosed less frequently. Moreover, the current study demonstrated that exocervical or endocervical RMs did not have different effects on the residual/recurrent status. We believe this was due to the use of a right-angled triangular loop in a single pass and the cold coagulator used in our study. Miroshnichenko et al  reported that LEEP using a ring-shaped loop was less likely to yield a single intact specimen and that an increase in the number of specimens obtained had a statistically significant negative effect on pathology interpretation. Adequate pathology interpretation using appropriate specimens is required to reduce residual tumors. Matsumura et al  previously suggested that one adequate specimen could be obtained in the majority of cases by using a triangular probe and a rigid linear electrode. This is because its relatively large size allows resection of the entire transformation zone and because its linearity allows resection of any lesion extending into the endocervix . Despite having similar positive RM rates, the present study may have more accurate data compared to other previous reports using a ring-shaped loop. Secondly, combined cold coagulator after LEEP might be beneficial both as a hemostatic technique and for reducing the proportion of abnormal smears during follow-up . From the literature, approximately 30–50% of cases with involved margins were found to have no residual tumor upon subsequent hysterectomy [17, 26, 27]. This likely indicates the presence of a mechanism that clears residual tumor cells in remnant cervical tissue after conization. Paterson et al  and White et al  suggested that local activation of cellular immunity after conization causes the regression of residual tumor cells. Additionally, hemostatic measures such as cold coagulation may play a role in destroying residual tumor at the RM, or may influence regression to normal tissue .
A strong point of our study was the analysis of all cases that had been treated according to standard practice guidelines at a new hospital since opening. Therefore, we believe the results were not biased due to operator or treatment policy factors. Secondly, the analysis was performed on CIN or AIS cases that were confirmed by colposcopically directed biopsy. Hence, preoperatively selected cases are likely to provide reliability to the study results.
There are however several limitations to this study. Firstly, this was a retrospective case series with a relatively small number of patients. Second, the study did not focus on postoperative complications such as postoperative bleeding, menstruation bleeding volume, pregnancy or preterm delivery. Although a larger volume or destruction by cold coagulator can result in a lower rate of positive RMs, the postoperative complications could increase. However, previous studies using a right-angled triangular loop and/or cold coagulator revealed similar or fewer postoperative complications compared with studies using a ring-shaped loop [14, 25]. Therefore, we believe the rate of postoperative complications in the present study may have been reasonable.