[Single-center efficacy analysis of surgical treatment for para-aortic lymph nodes metastasis in colorectal cancer].

Objective: To explore the feasibility, safety and oncologic value of para-aortic lymph node (PALN) dissection (including open, laparoscopic and robotic approaches) in colorectal cancer patients with clinically suspected PALN metastasis. Methods: A retrospective observational study was performed. Clinical data of 202 colorectal cancer patients who underwent synchronous PALN dissection at Fujian Medical University Union Hospital between 2011 and 2025 were retrospectively reviewed, including 40 open surgeries, 148 laparoscopic surgeries and 14 robotic surgeries. Perioperative surgical data were collected; postoperative complications were graded by the Clavien-Dindo classification. The metastatic pattern of PALN involvement were analyzed. Logistic regression analysis was performed to identify its risk factors. Survival analysis was conducted using the Kaplan-Meier method, and independent prognostic factors for overall survival (OS) were identified via Cox proportional hazards regression model. Results: Among all 202 patients, 106 (52.5%) had rectal tumors, 77 (38.1%) had sigmoid colon tumors, and 19 (9.4%) had descending colon tumors. All patients successfully completed PALN dissection. Postoperative complications occurred in 89 patients (44.1%), including 40 cases (19.8%) of chyle leak. According to the Clavien-Dindo classification: 4 cases (4.5%) were grade Ⅰ, 75 cases (84.3%) grade Ⅱ, 9 cases (10.1%) grade Ⅲ, and 1 case (1.1%) grade Ⅳ. No death occurred within 30 days after surgery. Postoperative pathology confirmed that the PALN positive rate was 33.7% (68/202). In the PALN-positive group, lymphovascular invasion was detected in 41 cases (60.3%, 41/68) and perineural invasion in 34 cases (50.0%, 34/68), which were significantly higher than those in the PALN-negative group [13.4% (18/134) and 25.4% (34/134), respectively], with statistically significant differences (all P<0.001). Multivariate Logistic regression analysis revealed that tumor N2 stage (OR=11.665, P<0.001), positive No.253 lymph nodes (OR=17.683, P<0.001), number of harvested regional lymph nodes (OR=0.946, P=0.002), number of resected PALNs (OR=1.106, P=0.002) and lymphovascular invasion (OR=4.522, P=0.007) were independent risk factors for PALN metastasis. A total of 170 patients who underwent simultaneous para-aortic lymph node (PALN) dissection between 2011 and 2022 were enrolled, with a median follow-up of 43 months. Among them, the 5-year OS was 41.1% in 54 patients with positive PALN, versus 86.8% in 116 patients with negative PALN, and the difference was statistically significant (P<0.001). The 5-year OS in the laparoscopic and robotic minimally invasive surgery group was 78.4%, which was significantly higher than that in the open surgery group (52.2%), with a statistically significant difference (P=0.003). Patients without postoperative complications had a 5-year OS of 77.1%, higher than those with Clavien-Dindo grade I-II complications (73.4%). The 5-year OS of patients with Clavien-Dindo grade I-IV complications was only 15.6%. Tumor location and preoperative treatment had no significant impact on OS (all P>0.05).Postoperative recurrence and metastasis developed in 48 patients (28.2%, 48/170), among whom 9 cases (5.3%, 9/170) had recurrent PALN metastasis. Multivariate Cox regression analysis demonstrated that open surgery (HR=2.099, P=0.044), more than 3 pathologically positive PALNs (HR=3.427, P=0.002), and postoperative Clavien-Dindo grade Ⅲ-Ⅳ complications (HR=6.436, P<0.001) were independent risk factors for poor OS after simultaneous PALN dissection. Conclusion: For colorectal cancer patients suspected of PALN metastasis in clinical practice, PALN dissection technique is safe and feasible, and perioperative complications are generally controllable. PALN cleaning can bring survival benefits to some patients with PALN metastasis, while attention should be paid to the prevention and control of serious postoperative complications to improve patient prognosis.