Spread of rectal cancer via lymphatic vessels results in the involvement of lymph nodes, located both upward and lateral. Lymphatic vessels go from the lower rectum through the lateral ligament and reach iliac lymph nodes, so that lateral ligament is believed to be crucial in the lateral lymphatic flow . Lateral lymphadenectomy is mainly practised in Japan. Lateral lymph nodes (middle rectal, obturator, internal iliac lymph nodes) are metastatic when tumours are located at or below the peritoneal reflection. The percentage of lateral lymph node involvement is assessed by many Authors on average as 9-18% and it ranges from 2.8% for T1 to 31-40% for T4 rectal tumours [39, 40]. All the Authors confirm that the percentage of lateral lymph metastases strictly depends on tumour growth. It was also observed that for the tumors with a lower margin above 6 cm from the dentate line, metastases in lateral lymph nodes occurred only in 0.6% of cases, while in tumours with lower margin below 5 cm above this line it ranged from 7.5% (for tumors between 4.1 and 5 cm) to 29.6% (for tumors between 0.1 and 1 cm). The main reason pelvic lymphadenectomy in rectal cancer (complete clearance of lateral lymphatic nodes) is performed is to improve survival and reduce local recurrence. However, retrospective studies conducted by many Authors confirmed no improvement in a 5-year survival rate in the patients in whom this procedure was performed when compared to the groups where conventional operations were conducted [39,41,42]. Moreover, it is highlighted that the risk of urinary and sexual dysfunction linked with lateral lymphadenectomy is too high and outweighs the risk of local recurrence associated with the presence of potential metastases in lateral lymph nodes . It is still unclear whether extended pelvic lymphadenectomy is an appropriate approach and it is very important to establish precise indications for carrying out this procedure.
Was this article helpful?