[Effect of peritoneum reconstruction on postoperative complications after laparoscopic low anterior resection for...

Objective: To determine the effect of peritoneum reconstruction on postoperative complications after laparoscopic low anterior resection (LAR) for rectal cancer. Methods: Retrospective cohort study and propensity score matching were conducted. Case inclusion criteria: (1) pathologically confirmed rectal adenocarcinoma; (2) 18 to 80 years; (3) patients with middle to low rectal cancer undergoing laparoscopic LAR; (4) patients staging cT1-4aN0-2M0 or ycT1-4aN0-2M0 after neoadjuvant therapy; (5) the distance of 4-10 cm from tumor low margin to anal verge. Exclusion criteria: (1) abdominal surgery history (except appendicitis, cholecystitis, ectopic pregnancy); (2) anastomosis above the peritoneal reflection; (3) tumor distant metastasis or clinical staging of T4b during surgery; (4) conversion to open surgery; (5) severe incapacitating disease (American Society of Anesthesiologists classification IV or V, ASA). A total of 666 patients with middle to low rectal cancer undergoing laparoscopic LAR in The First Affiliated Hospital of Army Medical University from January 2017 to June 2020 were enrolled. There were 473 males and 193 females with the median age of 59 (18-80) years. Laparoscopic LAR with peritoneum reconstruction was performed in 188 cases (PR group), and laparoscopic LAR without peritoneum reconstruction was performed in 478 cases (NPR group). After 1:1 propensity score matching according to 1:1 based on age, gender, body mass index, TNM staging, ASA classification, intraoperative blood loss, distance from tumor low margin to anal edge, 153 cases were included in each group. Postoperative complications were classified according to Clavien-Dindo classification. Anastomotic leakage was defined and graded according to the International Study Group of Rectal Cancer (ISGRC) criteria. Results: After propensity score matching, there were no significant differences in baseline demographic characteristics between the 2 groups (all P>0.05), indicating that these two groups were comparable. (1) Operative conditions: All the patients in both groups completed operation successfully. Compared with the NPR group, the PR group had longer operation time [(181.3±60.3) minutes vs. (168.9±51.5) minutes, t=2.185, P=0.029], shorter postoperative median hospital stay [8 (7, 10) days vs. 9 (7, 11) days, Z=-2.282, P=0.022], and the differences were statistically significant (P<0.05). (2) Postoperative complications: The overall morbidity of postoperative complication in PR group and NPR group was 20.3% (31/153) and 24.2% (37/153) respectively, and the incidence of anastomotic leakage was 9.8% (15/153) and 11.1%(17/153) respectively, whose differences were not statistically significant (both P>0.05). Compared with NPR group, PR group had lower morbidity of grade III to IV complications [3.9% (6/153) vs. 11.1% (17/153), χ(2)=5.688, P=0.017] and lower secondary operation rate [1.3% (2/153) vs. 5.9% (9/153), χ(2)=4.621, P=0.032], the differences were statistically significant (both P<0.05). Though PR group had lower incidence of grade C anastomoic leakage [1.3% (2/153) vs. 3.9% (6/153), χ(2)=2.054, P=0.152], but the differences were not statistically significant. (3) Postoperative inflammation: The difference of the procalcitonin level of both PR and NPR groups at postoperative 1-d, 3-d, and 5-d was statistically significant (F=5.222, P=0.010) in time-dependent manner, while the difference was not significant in the interaction effect (P>0.05). No statistically significant differences in the C-reactive protein level between two groups at postoperative 1-d, 3-d, and 5-d were found (all P>0.05). Conclusion: Peritoneum reconstruction in laparoscopic LAR can decrease the morbidity of postoperative complication of grade III to IV and the reoperation rate, and plays an important role in controlling the inflammatory reaction, which has great clinical value.