Preoperative factors associated with lateral lymph node metastasis in lower rectal cancer and the evaluation of the middle rectal artery

• Published in: Surgery today (Tokyo, Japan) Japan), 2024-12, Vol.54 (12), p.1472-1481
• Main Authors: Shiraishi, Takuya, Ogawa, Hiroomi, Yamaguchi, Arisa, Shibasaki, Yuta, Osone, Katsuya, Okada, Takuhisa, Sakai, Makoto, Sohda, Makoto, Shirabe, Ken, Saeki, Hiroshi
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Arteries - diagnostic imaging; Arteries - pathology; Female; Humans; Lymph Node Excision; Lymph Nodes - diagnostic imaging; Lymph Nodes - pathology; Lymphatic Metastasis; Male; Medicine; Medicine & Public Health; Middle Aged; Original Article; Positron Emission Tomography Computed Tomography; Predictive Value of Tests; Preoperative Period; Rectal Neoplasms - diagnostic imaging; Rectal Neoplasms - pathology; Rectal Neoplasms - surgery; Rectum - blood supply; Rectum - diagnostic imaging; Rectum - pathology; Rectum - surgery; Retrospective Studies; Surgery; Surgical Oncology
• ISSN: 0941-1291; 1436-2813; 1436-2813
• DOI: 10.1007/s00595-024-02868-0

Purpose This study aimed to identify cases in which lateral lymph node (LLN) dissection (LLND) can be excluded by clarifying preoperative factors, including an evaluation of the middle rectal artery (MRA), associated with LLN metastasis. Methods Fifty-five consecutive patients who underwent preoperative positron emission tomography–computed tomography (PET/CT) and total mesorectal excision with LLND for rectal cancer were included. We retrospectively investigated the preoperative clinical factors associated with pathological LLN (pLLN) metastasis. We analyzed the regions of pLLN metastasis using MRA. Results pLLN metastasis occurred in 13 (23.6%) patients. According to a multivariate analysis, clinical LLN (cLLN) metastasis based on short-axis size and LLN status based on PET/CT were independent preoperative factors of pLLN metastasis. The negative predictive value (NPV) was high (97.1%) in patients evaluated as negative based on PET/CT and cLLN short-axis size. MRA was detected in 24 patients (43.6%) using contrast-enhanced CT, and there was a significant relationship between pLLN metastasis and the presence of MRA. pLLN metastasis in the internal iliac region but not in the obturator region was significantly correlated with the presence of MRA. Conclusion Combined cLLN metastasis based on short-axis size and PET/CT showed a higher NPV, suggesting this to be a useful method for identifying cases in which LLND can be excluded.