The patient is positioned in the modified Lloyd-Davies position. Safe positioning of the patient’s bony prominent part is very important; padding of neurovascular bundles is performed to prevent damage. The surgeon is initially positioned on the left side of the patient, the first assistant is positioned on the right side, and the second assistant is positioned between the patient’s legs. During surgery, the surgeon can change sides several times as needed. After induction of anesthesia, an additional digital rectal examination is performed to verify the tumor location, height, mobility, and the involvement of any other organs.

A laparotomy is performed through a lower midline incision; great care is taken not to damage the bladder, which is usually dissected and retracted to the left because the 2 cm above pubic bone is quite important to optimize adequate visualization of the lower pelvis. After the midline laparotomy and intra-abdominal inspection, a wound retracting system is installed. The surgeon retracts the small bowel, right colon, omentum, and proximal left colon under the blades of the retractor to open the sigmoid colon and its mesentery. The optimal view should include the duodenum as an upper border, aorta and vena cava on the right side with the white line of Toldt on the left side.

We perform routine para-aortic lymphadenectomy for T3/4 rectal, sigmoid, and left colon cancers with the suspicious lymph nodes on preoperative diagnosis. The vascular pedicle containing IMA and fat tissue around it is approached in a lateral-to-medial direction. The sigmoid colon is lifted up and the avascular space behind it is entered. Applying traction and countertraction the posterior surface of the sigmoid mesocolon is released gently from the underlying Toldt’s and prerenal fascia, left ureter, gonadal vessels, and hypogastric plexus and nerve. The root of the IMA is reached from behind and peritoneum incision is made medial to the root of the IMA to connect the planes. The surgeon inserts the left index finger through the medial peritoneal incision and lifts up the IMA root with a hook, thus protecting underlying preaortic nerve plexus and other vital structures from injury while dissecting at the IMA root. The medial peritoneal incision is extended up to the duodenum and curved to follow the duodenum lower border. The latter is gently retracted cranially and carefully dissected. Next, the preaortic fascia is opened and fat tissue surrounding the IMA root is cleared off between the left and right splanchnic lumbar nerves leaving the latter intact. It is preferable to use Harmonic scalpel (Ethicon Endo-Surgery, Inc., Cincinnati, OH) to reduce nerve damage at this step. The preaortic fat and the fat around the root of IMA that contains apical lymph nodes is cleared off the aorta and the IMA surface and dissected downward. Using scissors or Harmonic scalpel the IMA is freed circumferentially from the paravasal fat all way down to the origin of the LCA, sigmoid arteries (SAs), and superior rectal arteries (Fig. 41-1). The mobilized preaortic and paravasal fat is posteriorly retraced. This method of vessel “skeletizing” enables performing extended para-aortic lymph node dissection together with precise isolation and separate dissection of IMA branches without excessive colon resection. To perform D3 lymph node dissection in upward direction, the space between the IMA and LCA should be cleared out and the fat with apical lymph nodes removed. The IMA can be divided either at the root or below the LCA depending on the length of the sigmoid colon and the possibility of using it for colorectal anastomosis. The inferior mesenteric vein is divided at the same level as IMA. Any type of vessel ligation technique can be used, including advanced bipolar device or an ultrasonic scalpel with advanced hemostasis technology.

Further mobilization of the sigmoid colon, colon division, and rectal mobilization fully correspond to the principles of nerve-sparing TME described in several other chapters.

LLD can be performed either en bloc with the mesorectum if there is direct tumor invasion outside mesorectal fascia or as a separate maneuver after the rectum has been removed. The concept of LLD is removing of fatty and connective tissue outside the PP, around the internal iliac and common iliac vessels, and in the obturator cavity. The results of nerve-preserving LLD are the skeletonized iliac vessels and their branches, and preservation of obturator nerve (ON) and pelvic autonomic nerves (ON and PP).

The lateral pelvic area is classified into four regions: common iliac (N2 lymph nodes), internal iliac (N2 lymph nodes—“second” space), obturator (N3 lymph nodes—third space), and external iliac, according to the Japanese classification. The common iliac lymph nodes are rarely dissected because
the frequency of metastasis in this area is low. Before the start of LLD, the ureter and gonadal vessels from the corresponding side of the pelvis are medially retracted and fixed with vessel loop to achieve good exposure. The following structures are the anatomic landmarks for LLD:

Three ways to enter and clear the obturator (third) space can be used.

The first approach is medial-to-lateral along the internal iliac vessels. The second method is paravesical, and the third technique is the lateral-to-medial approach that was developed by our group. We feel that this approach allows better visualization and manipulation in the obturator space. The surgeon stands on the side opposite to that of the dissection. The paravesical space is entered and the peritoneal dissection is extended to the external iliac vessels. The peritoneum across the external iliac artery is opened, the underlying vessels are freed (Fig. 41-2), and gently retracted medially with a vessel loop. Medial retraction of the iliac vessels helps access the caudal part of the obturator fossa, which is reached with difficulty by a conventional approach. The fat tissue is removed from the middle part of the obturator fossa between the external iliac vessels medially and psoas muscle laterally (Fig. 41-3). The external iliac vessels are pulled back to the lateral side of the obturator fossa and the fat removal is completed.