eP138 - Route Selection of Natural Orifice Specimen Extraction in Female Patients After Laparoscopic Anterior Resection for Colorectal Neoplasm

Purpose/Background: While short-term advantages of natural orifice specimen extraction (NOSE) are widely recognized, limited studies indicate the optimal NOSE route, transanal or transvaginal, in female undergoing laparoscopic anterior resection.Methods/Interventions: This is a Retrospective comparative study based on prospectively collected data from a single-center experience.We investigate the impact of different NOSE routes on surgical safety and local recurrence of female patients in colorectal cancer surgery. We included female patients who underwent curative laparoscopic anterior resection with NOSE for AJCC stage I–III sigmoid or upper rectal cancer in 2012-2021. Surgical safety and oncologic outcomes were compared between patients undergoing transanal or transvaginal NOSE. The receiver operating characteristic (ROC) curve was used to analyze the optimal threshold of tumor size, tumor site from anal verge and body mass index, in selection of NOSE routes during NOSE procedure with the dependent factor of specimen rupture.Results/Outcomes: Of 115 eligible patients, 95 underwent transanal NOSE and 20 transvaginal NOSE after laparoscopic AR. Median follow-up was 50.3 months. Although the tumor size was larger in transvaginal NOSE than transanal group (4.0 vs. 3.0, p=0.006), no statistically significant difference was noted in term of morbidity, rate of specimen rupture during NOSE procedure nor local recurrence. The optimal cutoff value of tumor size for transrectal NOSE route was 3.25cm which yielded an AUC 0.813 (95%CI 0.671-0.956; P-value=0.003). The optimal cutoff value of tumor size for transvaginal NOSE route was 4.20 cm which yielded an AUC 0.882 (95%CI 0.733-1.000; P-value=0.039). However, the cutoff value of tumor site from anal verge and body mass index did not reach statistically significantly different in ROC curve analysis. Cumulative local recurrence risk at 5 years was 0% and 2.4% (p=0.632) for transvaginal and transrectal route relatively, while 5-year disease-free survival for all tumor stages combined was 87.3% and 82.0% (p=0.383) in laparoscopic anterior resection with natural orifice specimen extraction and conventional extraction groups, respectively. T3 and T4 stages were the only variables independently associated with disease-free survival.Conclusion/

Discussion: Long-term oncologic outcomes of patients undergoing laparoscopic anterior resection with natural orifice specimen extraction for sigmoid and upper rectal cancer do not differ from those undergoing conventional extraction. Thus, natural orifice specimen extraction could be a viable alternative to reduce abdominal wall insult in laparoscopic colorectal operations for malignancy in selected patients.