Effect of surgical risk factors on the immediate results of robot-assisted surgery for rectal cancer

Aim: to evaluate the perioperative results of robot-assisted surgery for rectal cancer in a group of high-risk patients and the influence of surgical risk factors (obesity, male gender, neoadjuvant chemoradiotherapy (CRT), as well as the tumor localization within 8 cm of the anal verge). Patients and Methods: the retrospective study included 223 cases of patients (48.43% men, 51.57% women) with rectal cancer who underwent robot-assisted surgery in the period from 2015 to 2021. Patients had a high surgical risk and were included in the study in the presence of one of the following factors: body mass index (BMI) ≥30 kg/m2, male gender, preoperative CRT, tumor localization within 8 cm of the anal verge. In this study, the relationship of BMI, CRT, age and gender of patients with parameters such as 30-day postoperative mortality, the number of postoperative complications according to the Clavien — Dindo classification, conversion rate, volume of intraoperative blood loss, duration of surgery, quality of total mesorectumectomy (TME), number of removed lymph nodes, frequency of lesions of the circular and distal edges of resection was evaluated. Correlations of stages T and N, tumor localization, ASA index and the presence of operations in the anamnesis with the above parameters were also checked in order to exclude their influence on the studied phenomena. Results: correlations of risk factors with the surgery time were revealed using the Spearman's rank-order correlation: surgery time — gender: correlation coefficient (ρ) 0.25, p<0.001; surgery time — BMI: ρ=0.23, p=0.001; surgery time — CRT: ρ=0.17, p<0.01; surgery time — Z-line: ρ=0.27, p=0.003. The correlation of circumferential resection margin (CRM) quality with the Z-line ( ρ=0.26, p=0.011) was also revealed. Conclusion: when performing robot-assisted surgery for malignant rectal tumors, there was no effect of surgical risk factors (male gender, obesity (BMI ≥30 kg/m2), CRT) on the conversion rate, as well as on the immediate results of surgical treatment. Despite this, the complexity of such surgeries in patients of this category undoubtedly increases, which is noted in an increase in the time spent on them. KEYWORDS: robot-assisted surgery, rectal cancer, oncology, risk factors, surgical treatment, colorectal cancer. FOR CITATION: Moiseev M.E., Gladyshev D.V., Kovalenko S.A. et al. Effect of surgical risk factors on the immediate results of robot-assisted surgery for rectal cancer. Russian Medical Inquiry. 2023;7(4):191–195 (in Russ.). DOI: 10.32364/2587-6821-2023-7-4-191-195.