["Two spaces" lateral lymph node dissection based on fascia anatomy for low rectal cancer]

As a treatment of rectal cancer, lateral lymph node dissection (LLND) is still a controversial issue. The argument against LLND is that the procedure is complicated, and consequently results in a high incidence of postoperative urogenital dysfunction. The surgical modality from fascia to space is adopted by lateral lymph node dissection in "two spaces". This operation has significant advantages of clear location of nerves and blood vessels and simplified surgical procedures, so the surgical procedure can be repeated and modulated. The fascia propria of the rectum, urogenital fascia, vesicohypogastric fascia and parietal fascia constitute the dissection plane for lateral lymph node dissection.Two spaces refer to Latzko's pararectal space and paravesical space. During the establishment of fascia plane, the dissection of external iliac lymph node (No.293), commoniliac lymph node (No.273) and abdominal aortic bifurcation lymph node (No.280) can be performed. While in the "space" dissection, internal iliac lymph node (No.263), obturator lymph node (No.283), lateral sacral lymph node (No.260) and median sacral lymph node (No.270) can be removed. LD2 or LD3 lateral lymph node dissection prescribed by the Japanese Society of Colorectal Cancer can be completed according to the needs of the disease. This article describes the anatomical basis and standardized surgical procedures.