Clinical significance and efficacy of endoscopic ultrasound-guided tissue acquisition for para-aortic lymph node metastasis.

Objectives: Assessing para-aortic lymph node (PALN) metastasis in solid tumors is crucial for accurate staging. In clinical practice, PALN metastasis is typically diagnosed based on imaging findings; however, the efficacy of endoscopic ultrasound-guided tissue acquisition (EUS-TA) in diagnosing PALN metastasis remains insufficiently understood.

Methods: This single-center, retrospective study included patients who underwent EUS-TA of PALNs and computed tomography (CT). Final diagnoses were based on pathological findings or 12-month imaging follow-up.

Results: Among 167 patients, technical success was achieved in 162 (97.0%). EUS-TA demonstrated a sensitivity, specificity, and accuracy of 85.1% (63/74), 100% (88/88), and 93.2% (151/162), respectively, for PALN metastasis. These results showed significantly higher sensitivity (28.4% vs. 85.1%, P < 0.001) and accuracy (64.8% vs. 93.2%, P < 0.001) than those of CT. The accuracy of CT and EUS-TA was 86.8% vs. 89.5% for PALNs measuring <5 mm, 51.5% vs. 92.9% for those measuring 5-10 mm, and 84.0% vs. 96.0% for those measuring ≥10 mm, with a significant difference in the 5-10 mm category (P < 0.001). Among the 44 patients diagnosed with resectable pancreatic cancer using CT, the final diagnosis confirmed PALN metastasis in 10 (22.7%) patients, and EUS-TA preoperatively identified PALN metastasis in eight (18.2%) patients. EUS-TA significantly reduced unnecessary surgeries compared with CT-only diagnoses (P = 0.013).

Conclusion: Endoscopic ultrasound-guided tissue acquisition of PALNs offers high diagnostic accuracy and can detect PALN metastasis often missed by CT alone. Integrating EUS-TA into preoperative assessments has the potential to substantially reduce unnecessary surgeries, improve patient outcomes, and plan treatment strategies.