Should there be a specific length of the colon-rectum segment to be resected for an adequate number of lymph nodes in cases of colorectal cancers? A retrospective multi-center study

Oncological and Clinical Impacts of Routine Splenic Flexure Mobilization in Anterior Resection

Background Splenic flexure mobilization (SFM) is widely regarded as one of the most challenging steps in laparoscopic and robotic colorectal surgery, sparking ongoing debate. Some surgeons routinely advocate for SFM, citing its role in achieving greater left colonic reach, which facilitates a safe, tension-free, and well-vascularized anastomosis while adhering to oncological principles. Conversely, others argue that SFM does not consistently ensure these benefits and may increase the risk of complications, including splenic, bowel, or vascular injuries, as well as unnecessarily prolonging the procedure. While traditional surgical textbooks consider SFM a mandatory step in open colorectal resections, limited evidence supports its necessity in minimally invasive approaches. Aim This study aims to evaluate whether routinely mobilizing the splenic flexure offers advantages from both oncological and clinical perspectives. Materials and methods This retrospective cohort study evaluated the oncological and clinical outcomes of SFM versus splenic flexure preservation (SFP) in anterior resections for malignant pathologies. The study was conducted at New Cross Hospital in Wolverhampton, United Kingdom, over a 24-month period, from March 2022 to March 2024. Anterior resections for benign pathologies were excluded. Data analysis was performed using IBM SPSS Statistics for Windows, Version 24.0 (Released 2016; IBM Corp., Armonk, NY, USA) and Microsoft Excel (Microsoft Corporation, Redmond, WA, USA). Results This study included 94 patients, with 65 undergoing SFM and 29 having it preserved (SFP). No significant differences in baseline demographics (age and gender) were observed between the groups. Oncological outcomes revealed a significantly longer median length of resected specimens in the SFM group, although lymph node counts and high vascular ties were comparable between the groups. There were no differences in R0 resection rates. Clinical outcomes showed similar hospital stays and operation durations in both groups. The SFM group had a slightly higher rate of stoma formation but a lower incidence of anastomotic leaks compared to the SFP group. No significant differences in splenic injuries or other complications were noted. Conclusions Our study suggests that routine SFM offers certain oncological and clinical benefits. The specimens obtained were more complete for pathological staging. The additional length gained from the maneuver not only results in longer specimens but also provides sufficient mobility of the remaining colon, enabling anastomosis with minimal tension, which helps prevent anastomotic leaks. Surgeons may consider adjusting their practices based on the findings of this study.

Association between the number of retrieved lymph nodes and demographic/tumour-related characteristics in colorectal cancer: a systematic review and meta-analysis

OBJECTIVE

Clinical practice guidelines recommend retrieving at least 12 lymph nodes for correct staging in colorectal cancer. However, it is difficult to retrieve adequate lymph nodes because of various factors. We aimed to evaluate the association between the number of retrieved lymph nodes and demographic/tumour-related characteristics in colorectal cancer.

DESIGN

Systematic review and meta-analysis of primary studies.

DATA SOURCES

PubMed, Embase, Cochrane and Web of Science were searched from January 2016 to June 2023.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies that evaluated the association between retrieved lymph nodes and demographic/tumour-related characteristics in colorectal cancer were included.

DATA EXTRACTION AND SYNTHESIS

OR with 95% conference intervals was extracted and pooled.

RESULTS

A total of 54 studies containing 2 05 821 patients were included in this meta-analysis. The results showed that fewer nodes were retrieved from elderly patients (OR=0.70, 95% CI (0.54 to 0.90), p=0.005), and from tumours located in the left colon than in the right colon (OR=0.43, 95% CI (0.33 to 0.56), p<0.001). More lymph nodes were obtained from females than males (OR=1.15, 95% CI (1.04 to 1.28), p=0.006), from the advanced T stage (T3+T4) than T1+T2 stage (OR=1.57, 95% CI (1.25 to 1.97), p<0.001) and from the N2 stage than N0 stage (OR=1.32, 95% CI (1.15 to 1.51), p<0.001). Body mass index, ethnicity, N1 stage, M stage, tumour differentiation and lymph-vascular invasion were not significantly associated with the lymph node yield.

CONCLUSIONS

The study results suggest that clinicians have an increased opportunity to retrieve sufficient lymph nodes for accurate pathological staging to guide treatment decisions in patients with colorectal cancer who are young, female, with tumours located in the right colon, advanced T stage and N2 stage.

Influence of colonic mesenteric area on the number of lymph node retrieval for colon cancer: a prospective cohort study

PURPOSE

The minimum harvested 12 lymph nodes (LNs) is regarded as the limit for accurate staging of nodal status in colorectal cancer patients. Besides the association of the lengths of resected intestinal segments and vascular pedicles, the mesocolic mesenteric area's impact on LN count has not been studied. We aimed to evaluate the associations between metric variables, including the mesocolic mesentery area on the nodal harvest.

METHODS

All consecutive patients who underwent elective colectomy with a curative intention for colon adenocarcinoma were prospectively included. The metric variables included the lengths of resected intestinal segments, vascular pedicle, and colonic mesenteric area. The variables influencing the LN count and the correlation between the total LN count and the specimens' relevant metric measurements were analyzed.

RESULTS

There were 46 patients with a median age of 64 years. The median count for total LNs was 22, and the LN positivity was 59.2%. There was an inadequate LN yield (<12) in 3 patients (6.1%). No significant associations were found between the adequacy of nodal harvest and the demographic, clinical, and tumoral features (P>0.05). There were significant positive correlations between total LN number and length of vascular pedicle and mesenteric area (r=0.576, P<0.001 and r=0.566, P<0.001).

CONCLUSION

The length of the vascular pedicle and mesenteric area were significantly correlated with total LN counts. Although there was no significant impact on the length of resected segments, the colonic mesenteric area can be used alone as a measure for the assessment of the nodal yield in colon cancer.