[Efficacy and quality of life in laparoscopic right hemicolectomy with different extent of lymph node dissection]

Objective: To investigate the efficacy of laparoscopic right hemicolectomy using the left edge of the superior mesenteric artery (SMA) as the medial boundary for lymph node dissection, and its impact on patients' quality of life. Methods: Patients were included who had been clearly diagnosed with primary right colon cancer (located in the ileocecal region, ascending colon, and hepatic flexure of the colon) through endoscopic histopathological examination, were aged 80 years or younger, had completed laparoscopic complete mesocolic excision plus D3 radical resection for right colon cancer, and had complete quality of life assessments and follow-up records.A retrospective cohort study method was used. Clinical data of patients undergoing laparoscopic right hemicolectomy at Shengjing Hospital of China Medical University from January 2018 to December 2022 were collected.Based on the different medial boundaries of lymph node dissection, patients were divided into an arterial group (bounded by the left edge of the SMA, 119 cases) and a venous group (bounded by the left edge of the superior mesenteric vein, 89 cases).There were no statistically significant differences in baseline characteristics between the two groups (all P>0.05), and use theQuality of Life Questionnaire for Colorectal Cancer - 38 (QLQ-CR38) and the Diarrhea Assessment Scale(DAS)to evaluate the quality of life and diarrhea of patients one month, three months, and six months after surgery. Results: Compared with the venous group, more lymph nodes were dissected at the third station than in the arterial group (4.2±2.0 vs. 3.3±1.6, t=3.320, P<0.001). Additionally, the rates of positive lymph nodes at the third station (10.9% [13/119] vs. 3.4% [3/89], χ² =2.007, P=0.038) and the rates of positive lymph nodes at the third station among patients with Stage III disease (32.5% [13/40] vs. 8.6% [3/35], χ²=2.507, P=0.012) were both significantly higher in the arterial group. These differences are all statistically significant (P<0.05). There were no significant differences in the other perioperative data assessed between the two groups (all P<0.05). Application of generalized estimating equation analysis showed statistically significant differences between the two groups in terms of timing of gastrointestinal issues (P=0.024) and defecation problems (P<0.001). Further simple effects analysis of each of the assessed variables revealed that, one month after surgery, patients in the venous group had significantly less severe gastrointestinal symptoms (M [Q₁, Q₃]: 9 [7,13] vs. 11 [9,13], Z=2.416, P=0.016) and defecation dysfunction (M [Q₁, Q₃]: 13 [8,14] vs. 19 [16,22], Z=8.813, P<0.001) compared with the arterial group; these differences are all statistically significant (all P<0.05). Three months after surgery, the venous group showed significantly better defecation function than did the arterial group (M [Q₁, Q₃]:10 [6,13] vs. 11 [6,14], Z=2.591, P<0.001); this difference is statistically significant (P<0.05). However, 6 months after surgery, there were no statistically significant differences between the two groups in any of the assessed variables (all P>0.05).Generalized estimating equation analysis revealed statistically significant differences between the two groups in terms of bowel frequency (P=0.027), stool consistency (P=0.046), urgency to defecate (P=0.008), and total score (P<0.001) with regard to the group-by-time interaction (all P<0.05). Further simple effects analysis of each of the assessed variables showed that 1 month after surgery, patients in the venous group had better outcomes than those in the arterial group in terms of bowel frequency (M [Q₁, Q₃]:0 [0,2] vs. 2 [1,3]) points, Z=3.479, P<0.001), stool consistency (M [Q₁, Q₃]:0 [0,1] vs. 1 [0,2] points, Z=3.377, P<0.001), urgency to defecate (M [Q₁, Q₃]:0 [0,2] vs. 2 [1,3] points, Z=2.798, P=0.005), and total score (M [Q₁, Q₃]:3 [2,5] vs. 5 [4,7] points, Z=5.318, P<0.001); all of these differences are statistically significant (all P<0.05). Three months after surgery, outcomes in patients in the venous group remained superior to those in the arterial group in terms of bowel frequency (M [Q₁, Q₃]: 1 [0,1] vs. 1 [0,2] points, Z=2.230, P=0.026), stool consistency (M [Q₁, Q₃]: 0 [0,1] vs. 1 [0,1] points, Z=2.699, P=0.007), and total score (M [Q₁, Q₃]:3 [2,4] vs. 3 [2,4] points, Z=2.530, P=0.011); all of these differences are statistically significant (all P<0.05). However, 6 months after surgery, there were no statistically significant differences between the two groups in any of the four assessed variables or the total score. The median duration of follow-up was 41 (9-64) months. The 3-year overall survival rates were 93.3% and 95.8% in the venous and arterial groups, respectively; this difference is not statistically significant (P=0.403). However, the 3-year disease-free survival rate was 86.5% in the venous group, which is significantly lower than that in the arterial group (95.0%, P=0.027). Conclusion: Laparoscopic D3 lymph node dissection of the right colon using the left margin of the superior mesenteric artery as the medial boundary for lymph node dissection is safe and necessary, which can improve the disease-free survival time of patients. This surgical procedure affects the patient's quality of life in the short term,but gradually improves six months after surgery.