[Lymphographic visualization of the rectal lymphatic channels and nodes]

Area of Science:

• Radiology
• Oncology
• Surgical Pathology

Background:

• Accurate assessment of lymph node status is crucial for rectal cancer staging and treatment planning.
• Conventional methods for evaluating lymph node involvement can be limited in precision.

Purpose of the Study:

• To evaluate the utility of Lipiodol U.F. submucosal injections for lymph node visualization in rectal cancer patients.
• To assess the potential of this technique for determining lymph node drainage patterns and aiding in surgical assessment.

Main Methods:

• Lipiodol U.F. contrast medium was injected submucosally into the rectal wall (1.6 mm depth) in 13 patients (12 with rectal carcinoma, 1 with villous adenoma).
• Radiographs were taken at multiple time points (2, 4, 8, 24, 48 hours) to track contrast accumulation in lymph nodes.
• Tumor depth was consistently between 4 and 6 cm.

Main Results:

• Contrast medium accumulation in lymph nodes began within 2-4 hours, peaking around 12 hours.
• Lymphatic flow was observed longitudinally within the rectal wall.
• While lymph nodes were visualized, their small size precluded preoperative assessment of metastatic infestation.
• Postoperative radiographs served as a valuable tool to verify the radicality of surgical resection, particularly when lymph nodes were clearly delineated.

Conclusions:

• Submucosal Lipiodol U.F. injection is a feasible method for visualizing rectal lymph node drainage.
• The technique is limited by the small size of lymph nodes for preoperative staging.
• Postoperative imaging with this method can effectively confirm the completeness of surgical tumor removal.