Minimally invasive surgery (MIS) can often be used for surgical staging that includes pelvic and paraaortic lymph node excision and sometimes omentectomy and peritoneal biopsy. Also, for those without comprehensive staging at their primary surgery, MIS may allow a less morbid completion of cancer staging. Specific MIS qualities that are suited to lymphadenectomy include expanded magnified views within deep or narrow spaces and the ability to achieve fine dissection. In terms of landmarks and fields of dissection, MIS lymphadenectomy procedural steps are the same as those with the open abdominal approach described on pages 1169 and 1172. However, with an MIS approach to cancer staging, paraaortic lymphadenectomy is typically completed first. The needed pneumoperitoneum gradually distends bowel, and thus surgery higher in the abdomen is performed early to permit adequate bowel manipulation and displacement.
A thorough pelvic examination and history reveal factors that help determine the optimal surgical route for an individual patient. As described in Chapter 41, when considering MIS, patients with suspected extensive adhesive disease, morbid obesity, or significant cardiopulmonary disease may be poor candidates. Regardless of approach, preoperative imaging studies prior to lymphadenectomy may help guide the surgeon to suspicious lymph nodes.
General complications related to MIS are discussed in Chapter 41 and include entry injury to the major vessels, bladder, ureters, and bowel. More specific to MIS staging, acute hemorrhage is the most commonly associated complication. Additionally, ureteral damage, postoperative lymphocele, and nerve injuries can occur, particularly to the obturator and genitofemoral nerve. In addition, the risk of conversion to an open procedure is discussed. Conversion to laparotomy may be necessary if exposure and organ manipulation are limited or if acute hemorrhage cannot be controlled with MIS techniques. Finally, port-site metastasis is a rare but possible complication.
As mentioned, bleeding is a frequent problem with pelvic lymphadenectomy and may be exacerbated by retroperitoneal fibrosis. Accordingly, units of packed red blood cells are typed and crossmatched. Topical hemostatic agents may also prove valuable. Routine bowel preparation and antibiotic prophylaxis are not required for lymphadenectomy but may be indicated for other concurrent surgeries. Thromboembolism prophylaxis is warranted because of the VTE risk associated with cancer. Options are listed in Table 39-8.
Important basic MIS tools for laparoscopy include blunt graspers and scissors, whereas the EndoWrist monopolar scissors and the EndoWrist bipolar Maryland grasper are used with the robot. Additional instruments needed for lymphadenectomy include a combined irrigation/suction device, which clears fluid and bluntly dissects; endoscopic bag for node removal; two to three 5-mm instrument ports; 10-mm laparoscope port; 12-mm endoscopic-bag port; and energy devices for cutting and vessel sealing. For the last, several electrosurgical and ultrasonic energy-based devices are adapted for either laparoscopic or robotic cases. These include Harmonic scalpel, electrosurgical monopolar instruments, and electrothermal bipolar coagulator devices (LigaSure, ENSEAL, PK Dissecting Forceps). For laparoscopy, the argon-beam coagulator is another option. Laparoscope selection varies by surgeon, and a 0-degree scope is frequently used. For others, a 30-degree scope permits greater visibility in tight or angulated spaces.
Anesthesia and Patient Positioning
Laparoscopic lymphadenectomy is performed under general anesthesia. For VTE prophylaxis, lower extremity compression devices are placed, and legs are then positioned in adjustable booted support stirrups. Typically, low lithotomy position is selected due to concurrent hysterectomy, although supine may be appropriate for restaging procedures. As described in Chapter 41, appropriate positioning of legs within the stirrups and arms at the side is crucial to reduce nerve injury risks. Also, the patient is secured to the bed by means of a gel pad or bean bag with appropriate protective padding. This keeps the patient from sliding when placed in steep Trendelenburg position, which is needed to reflect bowel for retroperitoneal access.
To avoid stomach puncture by a trocar during primary abdominal entry, an orogastric or nasogastric tube is placed to decompress the stomach. To avert similar bladder injury, a Foley catheter is inserted. The abdomen is then surgically prepared. If hysterectomy is planned, then vaginal preparation is also done.
As described in Section 46-3, a 10-mm primary trocar for the laparoscope is placed either at or approximately 1 to 2 cm above the umbilicus using an open abdominal entry method. For paraaortic dissection, this port is placed far enough cephalad to permit visualization of the lower aorta. Accessory ports include a right and left lateral abdominal trocar and one above one of the anterior superior iliac spines, as shown in Figure 46-3.1.
Additional ports are placed according to surgeon preference or clinical circumstances. All ports ideally have a minimum of 8 cm between them to allow ample range of motion and for robotic procedures, to avoid arm collision.
Following insertion of the laparoscope, lymph nodes are grossly inspected during initial abdominal exploration. Unexpected positive nodes may alter a proposed operative plan in certain cases, particularly with cervical cancer. In addition, a decision is made to proceed with the MIS approach or convert to laparotomy.
Paraaortic Lymphadenectomy: Opening the Retroperitoneal Space
With the patient in steep Trendelenburg position, the small bowel is gently moved into the right and left upper quadrants. The first landmarks identified are the aortic bifurcation and right common iliac artery. The peritoneum over the midlength of the right common iliac artery is grasped, elevated, and sharply incised. This peritoneal incision is extended superiorly atop the right common iliac artery and then atop the aorta. Following each vessel’s course, the incision progresses to the curve of duodenum overlying the aorta (Fig. 46-12.1). Once the peritoneum is opened at this level, it is held anteriorly and cephalad by an assistant surgeon using graspers. Blunt and sharp dissection is performed by the surgeon to lift and displace the duodenum cephalad to expose the aorta. This small bowel is progressively lifted until the level of the inferior mesenteric artery (IMA) is reached as it exits from the aorta on the left.
Opening peritoneum over common iliac artery and aorta.
For this, the lateral peritoneal cut edge atop the right common iliac artery is grasped and elevated. Blunt dissection beneath this peritoneum progresses laterally until the right ureter is located as it crosses the common iliac artery. Once identified, the ureter is directed laterally with gentle blunt traction. This lowers ureteral injury risks during the remaining nodal dissection.
Right Paraaortic Lymph Nodes
To summarize lymphadenectomy within this anatomic area, the caudal end of the fatty, lymph node-containing tissue bundle is freed first. The surgeon then develops medial, lateral, and deep bundle margins and last frees the cephalad tip to permit bundle removal.
To begin, with the ureter held laterally and the inferolateral peritoneal edge elevated, the surgeon first develops the caudal border of this nodal group. Dissection begins at the midlength of the right common iliac artery and atop this artery’s lateral border. Within the overlying fatty tissue, small spaces are bluntly developed to create fibrous pedicles that can be lysed or coagulated and divided. In doing so, the distal end of the nodal bundle is progressively freed from the artery and can be elevated and brought cephalad.
Dissection then follows the artery’s course and moves medially atop its lateral border. During this dissection, small fibrous bands between the nodal bundle and the right common iliac artery are sequentially transected. Crossing the IVC and reaching the lower aorta, dissection continues atop the right lateral margin of the aorta until reaching the level of the IMA.
To establish the lateral border of this nodal group, the surgeon revisits the dissection’s starting point at the right common iliac artery’s midlength. Here, a plane is bluntly developed between the lateral border of the IVC and psoas major muscle. Blunt dissection in this plane frees the retroperitoneal fat and is extended cephalad to the level of the IMA.
At this point, the right paraaortic node bundle has been largely detached medially, distally, and laterally, and division of the deep bundle attachments can be performed. The nodal tissue is elevated and separated from the underlying IVC with gentle blunt dissection progressing cephalad. This dissection moves proximally atop the IVC to reach the level of the IMA (Fig. 46-12.2). During this progression, small pedicles that often contain minor vessels are developed. These pedicles and their multiple perforating vessels are sequentially isolated, clipped or coagulated, and divided. Typically, this is the most difficult part of the dissection because inadvertently avulsed vessels may bleed profusely. For control, hemostatic clips or coagulation can be used. Moreover, a small gauze sponge can be prophylactically placed into the abdomen to provide quick tamponade if required.
Dissection over the inferior vena cava.
At the level of the IMA, the nodal bundle can be excised by placing large vascular clips across the cephalad end and transecting it before the clip. Lymph nodes are extracted intact using an endoscopic bag through a 12-mm port. Once removed, this right nodal bundle is sent as an individual specimen.
Left Paraaortic Lymph Nodes
Acquisition of the left paraaortic lymph nodes begins atop the aorta at the level of the IMA. As on the right side, after the initial bundle tip is freed, the medial, lateral, and deep margins are developed. However, dissection moves caudally rather than cephalad and ends at the left common iliac artery’s midlength.
The cephalad end of this nodal group is first developed using sharp or electrosurgical dissection that begins just below the IMA (Fig. 46-12.3). Small spaces within the fatty tissue are bluntly opened to create fibrous pedicles that can be lysed or coagulated and divided. This frees the proximal end of the nodal bundle.
Dissection over the aorta.
To advance, the lateral peritoneal edge and colon mesentery are elevated to the left on tension, and fibrovascular attachments to left side of the distal aorta are sharply transected. This permits lateral retraction of the colon mesentery for exposure. The medial side of the bundle is next elevated with forceps to create tension across fibrous bands connecting the nodal bundle and aorta. These fibers are sharply divided. Similar dissection continues caudally atop the left border of the aorta toward its bifurcation. Upon reaching the bifurcation, dissection then moves caudally and slightly laterally atop the left common iliac artery’s lateral border to finish at this artery’s midlength.
To access the lateral border of this nodal group, a blunt tip carefully sweeps laterally to separate the lateral fatty lymphoid tissue from the overlying sigmoid colon mesentery and from the underlying ureter. The ureter serves as the lateral boundary of this nodal group. Opening this potential space allows the ureter and the ovarian vessels, which lie medial to the ureter, to be clearly identified. A blunt probe is then repositioned to gently lift the colon mesentery, its adjoining vessels, and ureter. With this lateral border now developed, dissection of nodal attachments continues caudad, staying medial to the ureter and reaching the midlength of the left common iliac artery.
After establishing the medial and lateral boundaries of the left paraaortic nodal group, the caudad tip of the nodal bundle is again grasped and elevated. From the midlength of the left common iliac artery, dissection beneath the bundle moves cephalad while transecting deep attachments between it and the lateral aorta and between it and the psoas major muscle (Fig. 46-12.4). Upon reaching the level of the IMA, the cephalad end of the fatty tissue is clipped and transected. The entire nodal group bundle is removed in toto within an endoscopic bag through the 12-mm port. It is submitted as an individual specimen.
Dissection to the level of the inferior mesenteric artery.
High Paraaortic Lymphadenectomy
In some instances, a surgeon may elect an extended laparoscopic dissection. The anatomic boundaries of a high paraaortic lymphadenectomy begin distally at the IMA and reach proximally to the entry level of the right ovarian vein and left renal vein into the IVC, respectively (Whitney, 2010). Typically, this extension is possible only in selected patients with favorable anatomy, such as thin body habitus. Otherwise, upper abdominal exposure is problematic. Other helpful maneuvers include having a second surgical assistant and placing additional right and left upper quadrant trocars. In contrast, robotic paraaortic lymphadenectomy stops at the level of the IMA. High paraaortic dissection to the level of the renal vein is technically difficult and infrequently performed. Reasons include poor visualization, limitations in spanning the distance with the robotic arms, and inability to turn the patient around without undocking and placing additional ports.
To begin laparoscopically, the peritoneum overlying the aorta at the level of the IMA is grasped and elevated cephalad to displace small intestine into the upper abdomen and provide exposure to the aorta. The surgeon dissects retroperitoneally atop the aorta to further mobilize the duodenum and displace it cephalad. Often a laparoscopic fan retractor positioned in the retroperitoneal space aids exposure of the upper aorta.
To develop the medial border of the right high paraaortic nodal group, the nodal bundle overlying the IVC is regrasped and held on traction to dissect and divide the fibrous attachments from the aorta’s anterior surface and right border. This begins caudally at the level of the IMA and ends cephalad at the right ovarian vein.
For the lateral border of this nodal group, the right ureter is identified and again retracted to the right. The lateral portion of the nodal bundle is then bluntly separated from the psoas muscle in a proximal direction. The ovarian vein will be encountered and may be individually sealed and divided depending on its proximity to lymph nodes slated for removal.
With both lateral and medial borders defined, the deep middle attachments of this nodal bundle are freed by gentle cephalad dissection over the IVC until the level of the right ovarian vein is reached. Last, the proximal border of the nodal bundle is detached and removed as described earlier.
Dissection of the high left paraaortic nodal group begins by placing laparoscopic clips on the IMA and dividing between using a vessel-sealing device. Alternatively, the IMA may be preserved if adequate exposure is available. This avoids potential bowel ischemia in those with poorly developed collateral vessels. The left ureter is again identified as the lateral border of this high nodal group and is held laterally by an assistant.
The surgeon performs blunt dissection with intermittent coagulation and division of fibrous or vascular pedicles to detach the nodal bundle in a cephalad direction. Dissection continues until it reaches the left renal vein, where the bundle is detached and removed.
Pelvic Lymphadenectomy: Retroperitoneal Entry
For this nodal resection, lymphoid tissue is removed within the area bounded by the psoas major muscle (lateral), the superior vesical artery (medial), the midlength of the common iliac artery (cephalad), and the deep circumflex iliac vein (caudad). To begin, the round ligament is transected, and the peritoneal leaf between the round and infundibulopelvic (IP) ligament is grasped, elevated, and incised parallel to the IP. Gentle traction is again applied to the round ligament, and the broad ligament’s anterior peritoneal leaf is opened to reach the vesicouterine fold in the midline. If radical hysterectomy is planned after pelvic lymphadenectomy, then pararectal and paravesical spaces are completely developed as described on page 1144 prior to pelvic lymph node removal.
Pelvic Lymphadenectomy: Distal Common Iliac Nodes
Bowel is first retracted sufficiently to allow access to the distal half of the common iliac artery. To remove this nodal group, the prior peritoneal incision atop the common iliac artery is extended from its midlength caudally to expose the artery. Ureterolysis, if not previously performed, is completed as described in Section 46-3, Step 4. The ureter is then bluntly retracted medially before beginning node dissection.
Lateral fatty lymphoid tissue may be removed by first elevating it with a blunt grasper and using electrosurgical dissection atop the common iliac artery’s lateral margin to establish a plane between the nodal bundle and artery. Blunt dissection to further separate the nodal tissue from the artery is continued caudad. Electrosurgical coagulation plus sharp incision is used to detach these nodes. Importantly, on the patient’s right side, the common iliac vein and inferior vena cava lie beneath the common iliac artery’s lateral margin, and thus careful node excision is prudent. Further dissection is performed atop the distal common iliac artery, which serves as the medial border for this nodal group. Upon reaching the common iliac artery bifurcation, lymphatic tissue excision continues caudally to incorporate the external iliac nodal group.
Removal of this lymph node group starts by freeing its lateral border. Tissue previously resected along the common iliac artery is elevated and placed on tension. Dissection then extends caudally along the lateral side of the external iliac artery until reaching the deep circumflex iliac vein. This vein crosses the distal external iliac artery and serves as the caudal boundary of this nodal group. Along this path, dissection bluntly develops a plane between medially located lymphoid tissue and lateral preperitoneal fat found above the psoas major muscle (Fig. 46-12.5). During dissection, the genitofemoral nerve running atop the psoas major muscle is ideally identified and protected.
Dissection between the external iliac artery and psoas major muscle.
Next, grasper traction is typically required to lift the nodal bundle above the external iliac artery beginning at the common iliac artery bifurcation. During caudal dissection, a blunt tool gently pushes into the fibrofatty tissue to create distinct pedicles that attach the nodal bundle to the artery. These pedicle attachments can then be coagulated and divided. Electrosurgery can be also used to obtain hemostasis as the lymph node bundle is progressively excised caudally.
The mobilized nodal bundle is next reflected medially to reveal the entire external iliac artery (Fig. 46-12.6). Medial traction is applied with forceps, and fine adventitial bands that connect nodes to the underlying external iliac vein are transected using electrosurgical cutting. In contrast to open surgery, the pneumoperitoneum and Trendelenburg position used during laparoscopy result in vein collapse. As a result, the external iliac vein is harder to distinguish and can be easily injured. Once completed, this external iliac nodal group dissection later permits safe entry into the obturator space, outlined in Step 13.
Dissection off the external iliac vessels.
The ureter is moved and held medially by a blunt instrument for protection and improved pelvic sidewall visualization. Beginning at the distal aspect of the superior vesical artery, the free nodal bundle is again elevated and placed on tension. Initial sharp excision of the internal iliac nodal group continues cephalad along the superior vesical artery and then along the internal iliac vessels (Fig. 46-12.7). As dissection approaches the common iliac artery bifurcation, the nodal attachments are fine and allow blunt disruption. At this point, both the external iliac and internal iliac nodes are completely dissected and can be submitted as one specimen or combined with obturator fossa lymph nodes, depending on surgeon preference.
Dissection off the internal iliac artery.
With the assistant surgeon holding medial traction on the superior vesical artery, the obturator fossa can be exposed. This fossa may be entered medially, between the external iliac artery and the psoas major muscle. Thereafter, the external iliac vessels are retracted medially so that the obturator space can be accessed from a lateral approach. Or, the obturator space can suitably be entered medially.
If present, nodal tissue along the inferomedial wall of the external iliac vein is transected with blunt and electrosurgical dissection. Also, accessory venous branches may be identified and coagulated.
Within the exposed fossa, obturator nodal tissue is grasped with forceps. This nodal bundle lies deep to the external iliac vein but superficial to the obturator nerve. With upward traction applied, blunt forceps or a suction/irrigation device tip moved gently side-to-side disrupts nodal tissue attachments to the obturator nerve (Fig. 46-12.8). This blunt dissection is performed in the center of the fossa to minimize injury to surrounding deep pelvic vasculature. This also clears off tissue to permit obturator nerve identification.
Dissection above the obturator artery.
Once this nerve is localized, dissection should purposely remain superficial to it. Firm fibrotic attachments may be electrosurgically transected under direct visualization. As the caudal end of the bundle is reached, it is usually tethered to the sidewall and freed sharply. At the cephalad end of the bundle, nodes are carefully separated sharply from the inferior aspect of the external iliac vein while avoiding obturator nerve injury. Nodal tissue deep to the obturator nerve is not routinely removed since the obturator artery and vein traverse this area. Laceration of either vessel can result in retraction and catastrophic hemorrhage that is difficult to control.
Pelvic lymph nodes are then removed in toto via endoscopic bag. The identical procedure is performed on the contralateral side.
Completion of Laparoscopic Staging and Omentectomy
The staging procedure for ovarian cancer includes obtaining multiple peritoneal biopsies from the cul-de-sac, pelvic sidewalls, and pelvic gutters, and from the diaphragm bilaterally. This can be performed with a blunt grasper and laparoscopic scissors, with or without electrosurgical coagulation. The surgical staging for ovarian cancer and for certain histologic subtypes of endometrial cancer (papillary serous and clear cell carcinoma) also includes omentum removal.
A laparoscopic omentectomy is performed by identifying and elevating the omentum away from the transverse colon. Avascular windows are created within the proximal omentum. The intervening vascular attachments are then ligated with a vessel-sealing energy tool or endoscopic stapler. Once completely dissected, the omentum is placed in an endoscopic bag and removed through a transabdominal 12-mm port. In many women, the omentum is large and therefore is brought through the vagina if a laparoscopic hysterectomy is performed. All specimens undergo minimal manipulation and are removed through an endoscopic bag to help decrease the risk of port-site or intraabdominal tumor implantation.
Port Removal and Fascial Closure
Once procedures are completed, areas are inspected for bleeding. Topical hemostatic agents may be used and are listed in Table 40-5. If hemostasis is achieved, trocars are removed and port sites closed. Fascial defects larger than 10 mm are sutured to decrease the risk of herniation at those sites. Interrupted stitches of 0-gauge delayed-absorbable suture are placed to reapproximate this fascia. Alternatively, a dedicated trocar-site closure device, described in Chapter 41, can be used. Regardless of technique, the defect is palpated to confirm adequate closure.
The postoperative course following MIS staging lymphadenectomy generally follows that after other major laparoscopic surgery. Patients usually are able to tolerate clear liquids quickly, followed by a regular diet and discharge on postoperative day 1. With their pain typically controlled with oral pain medication, patients ambulate early.
Postoperative complications may include pelvic lymphocele formation, neurologic injuries, or trocar-site herniation. One long-term potential complication of pelvic lymphadenectomy is lymphedema. The exact incidence is unknown, but estimates range from 1 to 27 percent after surgical staging for endometrial cancer (Todo, 2010). The risk increases if more lymph nodes are removed or if pelvic radiation is administered after surgery. Treatments, which may or may not be successful, often include compression stockings, lower extremity wrapping, and massage therapy to manipulate lymph channels. Although generally not associated with an adverse outcome, this complication can significantly lower a patient’s quality of life postoperatively.