Localization of mesenteric lymph node metastases in relation to the level of arterial ligation in rectal cancer surgery

A comparative study of the pathological outcomes of robot-assisted versus open surgery for rectal cancer

PURPOSE

The use of robot-assisted surgery for rectal cancer is increasing, but the pathological outcomes have not been fully clarified. We compared the surgical and pathological outcomes between robot-assisted and open surgery in specimens from patients operated on for rectal cancer.

METHODS

All patients who underwent resection for rectal cancer from 2016 to 2018 were included (n=137). Specimens were divided into 3 sections to analyze the pathology of the lymph nodes.

RESULTS

The total specimen lengths were shorter in the robot-assisted group than in the open surgery group (mean±standard deviation: 29.1±8.6 cm vs. 33.8±9.9 cm, P=0.004) because of a shorter proximal resection margin (21.7±8.7 cm vs. 26.4±10.6 cm, P=0.006). The number of recruited lymph nodes (35.8±21.8 vs. 39.6±16.5, P=0.604) and arterial vessel length (8.84±2.6 cm vs. 8.78±2.4 cm, P=0.891) did not differ significantly between the 2 surgical approaches. Lymph node metastases were found in 33 of 137 samples (24.1%), but the numbers did not differ significantly between the procedures. Among these 33 cases, metastatic lymph nodes were located in the mesorectum (75.8%), in the sigmoid colon mesentery (33.3%), and at the arterial ligation site of the inferior mesenteric artery (12.1%). The circumferential resection margin and the proportion of complete mesorectal fascia were comparable between the groups.

CONCLUSION

There were no significant differences between the 2 surgical approaches regarding arterial vessel length, recruitment of lymph node metastases, and resection margins.

Level of inferior mesenteric artery ligation does not affect rectal cancer treatment outcomes despite better cancer-specific survival after low ligation-randomized trial results

AIM

In rectal cancer surgery, the problem about which of the mesenteric artery ligation variants (high or low) is more beneficial to the patient remains unsolved. Recent meta-analyses suggest that the risk of surgical complications is similar for both ligation variants. The main objective was to compare the survival time in both groups with a minimum 48 months' follow-up. Secondary objectives were comparison of the number of harvested lymph nodes, the complication rate and other selected data related to the surgery.

METHOD

This was a randomized, single-centre, unblinded clinical trial of adult patients (n = 130) with cT1-3M0/ycT0-3M0 rectal and rectosigmoid junction adenocarcinoma undergoing radical open surgery. The intervention level was inferior mesenteric artery ligation.

RESULTS

The mean and median survival in the whole group was 45 months, while in the survivor group it was 83 and 82 months. The survival for 1-5 years, overall survival and disease-free survival were similar in both groups. The cancer-specific survival time was longer in the low inferior mesenteric artery ligation group (P = 0.005 for all and P = 0.02 for pTNM Stage III patients) There were no differences in the incidence of anastomotic leakage and overall morbidity. The median number of lymph nodes located at the root of the inferior mesenteric artery was 1; the mean was 1.7. They were not metastatic in any case. The median total number of harvested nodes was similar in both groups.

CONCLUSIONS

In radically treated adenocarcinoma of the rectum and the rectosigmoid junction, the level of inferior mesenteric artery ligation below the left colic artery branch provides similar treatment results to inferior mesenteric artery ligation just below its branching from the aorta in relation to overall and disease-free survival, and the risk of complications. Low inferior mesenteric artery ligation results in better cancer-specific survival. The risk of metastases at the mesenteric nodes is negligible.

Risk factors for developing anorectal dysfunction after anterior resection

BACKGROUND

Anterior resection (AR) may result in defecatory dysfunction and the cause is multifactorial. The aim was to explore if dysfunction could be related to the part of the colon used for anastomosis (sigmoid or descending) and to identify other possible risk factors for bowel dysfunction after AR.

METHODS

This is a retrospective study based on prospectively registered data from a regional registry at the surgical department in Västmanland 1996-2019. Bowel function was registered at 1 year after AR or after stoma reversal. In total, 470 stage I-III rectal cancer patients had AR whereof 412 were included in this study.

RESULTS

Clustering was seen in 57%, incontinence 29%, urgency 22%, and evacuatory dysfunction 16%. The part of the colon used for anastomosis, level of vascular tie, and gender were not significantly associated with defecatory dysfunction. The higher the anastomotic level, the lower the risk of incontinence (OR 0.75; CI 0.63-0.90; p < 0.001) and clustering (OR 0.78; CI 0.67-0.90; p < 0.001). Compared with patients without a loop-ileostomy, an increased risk of clustering (OR 1.89; 1.08-3.31; p = 0.03), incontinence (OR 2.48; 1.29-4.77; p < 0.01), and urgency (OR 4.61; CI 2.02-10.60; p < 0.001) was seen after loop-ileostomy closure. Preoperative radiotherapy had a negative impact on continence and clustering seen mainly in the unadjusted analysis.

CONCLUSION

The part of the colon used for anastomosis was not a significantly associated functional outcome after anterior resection. Low anastomotic level and having had a diverting ileostomy were independent risk factors associated with negative functional outcomes.