Long-term clinical outcomes after high and low ligations with lymph node dissection around the root of the inferior mesenteric artery in patients with rectal cancer

Abstract

Purpose: This study aimed to evaluate the long-term clinical outcomes based on the ligation level of the inferior mesenteric artery (IMA) in patients with rectal cancer.Methods: This was a retrospective analysis of a prospectively collected database that included all patients who underwent elective low anterior resection for rectal cancer between January 2013 and December 2019. The clinical outcomes included oncological outcomes, postoperative complications, and functional outcomes. The oncological outcomes included overall survival (OS) and relapse-free survival (RFS). The functional outcomes, including defecatory and urogenital functions, were analyzed using the Fecal Incontinence Severity Index, International Prostate Symptom Score, and International Index of Erectile Function questionnaires.Results: In total, 545 patients were included in the analysis. Of these, 244 patients underwent high ligation (HL), whereas 301 underwent low ligation (LL). The tumor size was larger in the HL group than in the LL group. The number of harvested lymph nodes (LNs) was higher in the HL group than in the LL group. There were no significant differences in complication rates and recurrence patterns between the groups. There were no significant differences in 5-year RFS and OS between the groups. Cox regression analysis revealed that the ligation level (HL vs. LL) was not a significant risk factor for oncological outcomes. Regarding functional outcomes, the LL group showed a significant recovery in defecatory function 1 year postoperatively compared with the HL group.Conclusion: LL with LNs dissection around the root of the IMA might not affect the oncologic outcomes comparing to HL; however, it has minimal benefit for defecatory function.

To go high, or to go low: the never-ending debate of inferior mesenteric artery ligation

“…Given the recurrence locations in the low ligation group, the authors proposed that high ligation might be a safer oncological procedure. However, Lee et al [4] reported no differences in 5-year OS and RFS between the high and low IMA ligation groups in their recent study. Other research has similarly failed to demonstrate oncological benefits associated with high ligation of the IMA.…”

“…However, no significant differences were observed between the groups in terms of the number of harvested LNs, LN metastasis, 5-year mortality rate, 5-year disease-free survival rate, duration of surgery, intraoperative blood loss, or postoperative ileus. Lee et al [4] also reported no difference in AL rates between high and low ligation; similarly, an RCT by Fujii et al [7] involving 331 patients found no differences in AL rates between the 2 ligation techniques. Since AL is a potentially life-threatening surgical complication, a larger, multicenter RCT is essential to resolve these conflicting findings.…”

“…Nonetheless, concerns have been raised about the potential complications associated with high ligation of the IMA, such as anastomotic leakage and nerve injury [3]. The recent study by Lee et al [4] has addressed these issues, evaluating the long-term clinical outcomes of high versus low IMA ligation in patients with rectal cancer.…”

“…Although many surgeons suspect that damaging the autonomic nerve plexus during high ligation of the IMA may negatively impact genitourinary and bowel function, there has been limited research on this topic. Lee et al [4] explored the impact on defecatory function and found that the Fecal Incontinence Severity Index scores were better in the group that underwent low ligation. Similarly, Koda et al [8] examined the effects of high versus low IMA ligation on defecatory disorders following low anterior resection for rectal cancer.…”

“…Some research even suggests that IMA ligation may need to be customized based on lymph node involvement and underlying conditions such as diabetes mellitus and atherosclerosis, which could lead to relatively subjective decision-making [9,10]. In this context of conflicting findings, the study by Lee et al [4], which includes 545 patients, contributes significantly to the existing literature.…”