Impact of robotic surgery on systemic immune-inflammation index in gastric cancer patients: a retrospective cohort study.

[OBJECTIVE] Robotic surgery has been gaining attention because of the physical and metabolic morbidity of the conventional open technique. The systemic immune-inflammation index has emerged as a recent and more reliable biomarker. In our single-center retrospective cohort study, we investigate systemic immune-inflammation index in robotic gastrectomy in order to show the advantageous effect on the immune system, which we think is the first study in the literature.

[METHODS] The study involved patients from a high-volume center for 32 months. The patients were allocated into three groups: patients with robotic (1), laparoscopic (2), and open surgery (3). Venous blood was derived on the postoperative 24th hour. The systemic immune-inflammation index scores were compared in three groups in terms of Group 1 vs. Groups 2 and 3, Groups 1 and 2 vs. Group 3, and compared with platelet-lymphocyte ratio, neutrophil-lymphocyte ratio scores.

[RESULTS] Robotic surgery was performed in 55 patients, laparoscopic surgery in 13 patients, and open surgery in 248 patients. In the comparison of minimally invasive surgery (Groups 1+2) vs. open surgery (Group 3), systemic immune-inflammation index, platelet-lymphocyte ratio, and neutrophil-lymphocyte ratio were found to be significantly lower in the minimally invasive surgery group (p<0.05). The comparison between robotic surgery patients (Group 1) and patients with laparoscopy/open surgery (groups 2 and 3) showed that systemic immune-inflammation index, platelet-lymphocyte ratio, and neutrophil-lymphocyte ratio were significantly lower in Group 1 (p<0.05). neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, and systemic immune-inflammation index values were analyzed by receiver operating characteristic curve test, and the area under curve value of systemic immune-inflammation index was found to be higher in minimally invasive surgery group (robotic+laparoscopic) (p<0.05).

[CONCLUSION] The study reveals the superiority of robotic gastrectomy as a more feasible and high-quality procedure over conventional techniques in terms of better preservation of immune system function using a reliable and noninvasive serum biomarker.