Inflammatory stress response after transanal vs laparoscopic total mesorectal excision: a cohort study based on the TaLaR trial

Background: Transanal total mesorectal excision (taTME) is a novel approach to radical surgery for low rectal cancer; however, it is not clear whether taTME causes a more severe inflammatory stress response than laparoscopic total mesorectal excision (laTME). Therefore, the authors conducted this study to address this question, with the secondary objective of analyzing the predictive effect of inflammatory indexes on postoperative infective complications between laTME and taTME.Methods: A total of 545 cases of laTME and 544 cases of taTME from the TaLaR randomized controlled trial were included. Inflammatory stress response was assessed via C-reactive protein (CRP), white blood cell count, neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, lymphocyte-monocyte ratio, and prognostic nutritional index. Inflammatory indexes were measured and calculated preoperatively (t1) and on postoperative days one (t2) and seven (t3). The accuracy of inflammatory indexes as predictor of infective complications was evaluated by areas under the receiver operating characteristic curve.Results: Preoperative blood parameters were comparable between the two surgical methods. There were no significant differences in CRP, white blood cell count, neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, lymphocyte-monocyte ratio, or prognostic nutritional index between the two surgical methods at any time point (P>0.05). Among the inflammatory indexes at three time points, CRP on the first postoperative day was the most accurate predictor of infective complications, which is suitable for two surgical methods. The AUC was 0.7671 (P<0.0001) with a cutoff of 39.84 mg/l, yielding 94% sensitivity and 47% specificity.Conclusions: Compared with laTME, taTME surgery has no obvious disadvantage with respect to the postoperative inflammatory stress response. In addition, inflammatory indexes were favorable in predicting infective complications, with the best results for CRP on the first postoperative day. Defining the specific predictors for laTME and taTME is unnecessary.