BackgroundWe mainly evaluated whether preserving the inferior mesenteric artery (IMA) sheath to dissecting IMA root lymph nodes (also called No.253 lymph nodes) would benefit patients in terms of comparable lymph-node yield removed during operation and postoperative complications in laparoscopic radical resection of rectal cancer.MethodsThis is a prospective study included 141 rectal cancer patients who received laparoscopic radical resection during September 2018 to December 2020. All patients were randomly assigned to the preserved group (n = 71) and the peeled group (n = 70). The baseline characteristics, pathological features, intraoperative and postoperative data outcomes and complications were analyzed by independent samplesttest, chi-square test or Fisher’s exact test between the 2 groups.ResultsThe baseline characteristic and pathological features had no statistical difference between the 2 groups. The preserved group had a shorter operative time (P= 0.002), a shorter lymph node dissection time (P< 0.001), less intraoperative bleeding (P= 0.004), an earlier time to first flatus (P= 0.013), an earlier time to fluid intake (P= 0.033) and a shorter length of hospitalization (P= 0.012) than the peeled group. The differences between the 2 groups were not statistically significant (P> 0.05) in regard to the total number of lymph nodes cleared, positive lymph nodes, bleeding, anastomotic leakage, pneumonia, wound infection, abscess, ileus, urinary retention, urinary tract infection and chyle leakage.ConclusionPreserving of the IMA sheath in laparoscopic radical surgery for rectal cancer will reduce the total operation time and the length of hospitalization. This surgical method could lead to lower complication rate and faster recovery.Trial registrationThe study was approved by the Ethics Committee of The First Affiliated Hospital of Wannan Medical College and registered by the China Clinical Trials Registry (ChiCTR2200060830, Date of Registration:2022-06-12 -retrospective registration)http://www.chictr.org.cn/index.aspx.