Laparoscopic and Robotic Retroperitoneal Lymph Node Dissection





Laparoscopic retroperitoneal lymph node dissection (RPLND) was initially described by Rukstalis and Chodak in 1992. Laparoscopic RPLND was used for staging purposes; however, at select centers, laparoscopic RPLND has evolved into an identical replication of the open technique. Laparoscopic RPLND can be performed with therapeutic intent, offering control of the retroperitoneum with the benefits of a laparoscopic approach, including limited convalescence and reduced blood loss. Proper application of nerve-sparing techniques may yield preserved antegrade emission rates of greater than 90%. The past decade has seen the introduction of robotic-assisted laparoscopic RPLND benefitted by technical advantages, which may abbreviate the traditionally steep learning curve of conventional laparoscopy. The addition of robotic assistance potentially allows for a more widely reproducible form of minimally invasive RPLND secondary to the well-described benefits of three-dimensional imaging, improved ergonomics, and wristed instrumentation yielding reduced surgeon tremor and fatigue with more precise dissection.


Staging


Clinical staging of testis cancer is described elsewhere and is independent of the approach to retroperitoneal nodal dissection. Briefly, after performance of radical orchiectomy serum tumor markers (alpha-fetoprotein, chorionic gonadotropin, lactate dehydrogenase) are followed until they are undetectable before consideration of RPLND. Patients with persistent tumor markers are ineligible for RPLND and receive chemotherapy. Computed tomography imaging of the chest, abdomen, and pelvis is performed.




Indications


There are several clinical scenarios in which laparoscopic retroperitoneal lymph node dissection (LRPLND) is considered, and surgical templates are modified based on the patient’s clinical stage. Unilateral modified template LRPLND may be performed in patients with clinical stage I nonseminomatous or mixed germ cell tumors (GCTs). Select patients with stage II nonseminomatous or mixed GCTs with small volume retroperitoneal lymphadenopathy may be treated with bilateral modified template LRPLND. Extension to a full bilateral template should be performed if viable tumor is discovered during modified procedures. LRPLND can also be applied in the setting of patients with nonseminomatous GCT and normalized serum tumor markers with residual masses after chemotherapy. Technical challenges related to the desmoplastic reaction of tissues caused by chemotherapy, and the necessity to perform full bilateral template should limit the performance of this procedure to surgeons with extensive laparoscopic experience. Additional indications for LRPLND include clinical stage I paratesticular rhabdomyosarcoma and clinical stage I Leydig cell tumor. LRPLND is not indicated in those with pure seminomatous GCT. Robotic assistance may be used in any of the preceding clinical scenarios by those with experience in advanced robotic techniques.




Patient Preparation


Before LRPLND, all patients should undergo mechanical bowel preparation and type and crossmatch. Patients who have received bleomycin are at risk of pulmonary complications, and thus preoperative pulmonary function tests should be performed to identify patients at risk of pulmonary fibrosis and to aid in postoperative management. Preoperative sperm banking should be discussed.




Node Dissection Templates


Lymph node dissection templates are described elsewhere in this text. Briefly, right-sided unilateral template LRPLND includes all nodal tissue between the right ureter laterally, the renal vessels superiorly, the aorta (including the preaortic nodes), and the junction between the ureter and the common iliac artery inferiorly. Inclusion of the paraaortic nodes as well as the performance of a nerve-sparing bilateral dissection can routinely be performed. Left unilateral template LRPLND is bordered by the ureter laterally, the vena cava (including precaval nodes) medially, the junction between the ureter and the common iliac artery inferiorly, and the renal vessels superiorly. Bilateral modified templates are typically performed for stage IIA, limiting dissection on the contralateral side below the level of the inferior mesenteric artery (IMA). Similarly, extension to a full bilateral LRPLND may be performed. The authors’ typical approach is to perform a template dissection as described earlier. If metastatic disease is suspected intraoperatively, a full bilateral template dissection is performed. The retrocaval and retroaortic nodal packets are excised in all cases, resulting in an exact replication of open RPLND. In cases of postchemotherapy residual radiographic adenopathy with normalized serum tumor markers, a full bilateral template should be performed with nerve sparing, if feasible. Ideal candidates for postchemotherapy minimally invasive RPLND are those with residual masses smaller than 5 cm in diameter.




Nerve-Sparing Procedure


Preservation of antegrade emission necessitates preservation of the autonomic sympathetic fibers during RPLND. Retroperitoneal preganglionic sympathetic fibers originate from the thoracolumbar (T10–L2) spinal cord. These fibers then synapse within the ganglia of the paired and interconnected sympathetic trunks lying on either side of the spinal column. The columns lie in close approximation to the great vessels, the right posterior to the inferior vena cava (IVC), and the left posterolateral to the aorta. Exiting as postganglionic fibers, these fibers travel anteriorly along the abdominal aorta to the superior hypogastric plexus located anterior to the aortic bifurcation. Identification and maintenance of these structures is vital for nerve sparing but should not compromise the oncologic goals of the procedure.




Laparoscopic Retroperitoneal Lymph Node Dissection


Positioning and Trocar Placement


The operating room (OR) setup for LRPLND is shown in Fig. 119.1 . Both the operating and assistant surgeon stand on the same side of the patient. Two monitors are positioned on either side of the patient. Standard laparoscopic instruments are used throughout the procedure, including a 10-mm, 30-degree laparoscope; Veress needle; atraumatic grasping forceps; endoshears; clip appliers; and an irrigation and suction device. Equipment specific to LRPLND includes a laparoscopic paddle retractor, radiolucent polypropylene clips (Hem-o-lok; Weck Closure Systems, Triangle Park, NC), laparoscopic needle driver loaded with 4-0 Prolene suture, oxidized cellulose (Surgicel; Ethicon, Piscataway, NJ), and laparoscopic bipolar coagulation.




FIGURE 119.1


Operating room setup for laparoscopic retroperitoneal lymph node dissection.

(From Allaf ME. Laparoscopic retroperitoneal lymph node dissection. In Bishoff JT, Kavoussi LR, eds. Atlas of laparoscopic urologic surgery . Philadelphia: Saunders; 2007:238-249.)


General anesthesia is administered, followed by placement of a Foley catheter and nasogastric tube. Sequential pneumatic compression devices applied are used throughout the procedure. The patient is secured onto the OR table in the supine position with both arms tucked to the side. Pneumoperitoneum is established via a Veress needle placed at the umbilicus. Four equally spaced 12-mm laparoscopic ports are placed in the midline beginning 2 to 4 cm below the xiphoid process ( Fig. 119.2 ). If needed, an additional 5-mm port may be placed in the midaxillary line midway between the iliac crest and ribs for additional retraction. The bed is rotated away from the targeted side to allow the bowel segments to fall away from the operative field. Port placement is similar in bilateral procedures, and the bed is rotated toward the opposite side midprocedure to facilitate contralateral dissection. Similar port placement and midprocedure contralateral “airplane” rotation is used to facilitate dissection during bilateral template procedures. Bilateral template procedures, particularly those performed in postchemotherapy settings, are technically challenging. Therefore, it is advisable to ensure equipment necessary for conversion to an open procedure should be easily accessible if the need arises.




FIGURE 119.2


Placement of ports for laparoscopic retroperitoneal lymph node dissection.


Right-Sided Laparoscopic Retroperitoneal Lymph Node Dissection


Right-sided dissection begins with complete mobilization of the ascending colon. Incision of the white line of Toldt from the iliac vessels to the hepatic flexure is performed ( Fig. 119.3 ). A paddle retractor, introduced through the lowermost port, is used by the assistant to retract the bowel medially. The three most cephalad ports are used by the primary surgeon to begin the dissection. Care is taken to avoid injury of the mesenteric vessels. The duodenum is identified, and a Kocher maneuver is carried out using sharp dissection without cautery. This allows exposure of the anterior surfaces IVC, right renal vein, and contralateral renal hilum.




FIGURE 119.3


Right-sided laparoscopic retroperitoneal lymph node dissection. Incision of the white line of Toldt from the iliac vessels to the hepatic flexure.


After colonic mobilization, the primary surgeon then shifts trocars to use the three lower-most ports. The ipsilateral internal inguinal ring is identified and the peritoneum incised to mobilize the spermatic cord remnant ( Fig. 119.4, A ). The suture securing the spermatic cord is identified. The gonadal vein and all associated lymphatics are then dissected in a cephalad direction to the vein’s insertion into the IVC. Care should be taken to avoid injury to the inferior epigastric vessels and unnecessary hemorrhage ( Fig. 119.4, B ). The gonadal vein is doubly clipped and divided at its insertion into the IVC, thus excising the entire gonadal vein and associated lymphatics ( Fig. 119.5, A ). Special care must be taken during right-sided dissections to avoid avulsion of the gonadal vein off of the IVC. The spermatic artery is clipped and transected where it crosses over the vena cava ( Fig. 119.5, B ). The ureter is then identified as it crosses the iliac vessels. All of the lymphatic tissue between the ureter and the great vessels is excised using the “split-and-roll” technique. Gentle anterior mobilization of the ureter with the suction irrigator by the assistant may aid in mobilization of distal lymphatic tissue. All lymphatics are clipped before division to reduce risk of lymphocele development. The adventitia overlying the IVC is incised from cranial to caudal, superiorly to the renal vein and inferiorly to the common iliac vessels ( Fig. 119.6 ). The lateral nodal tissue comprising the precaval and paracaval lymph node packet is lifted, and blunt dissection is carried down to the lumbar vessels. The borders of this packet include the common iliac vessels inferiorly, the IVC medially, the ureter laterally, and the right renal vein superiorly ( Fig. 119.7 ). The irrigator–aspirator is an effective blunt dissection tool for this dissection. Lumbar vessels are identified, doubly clipped, and divided ( Fig. 119.8 ). Medial and anterior traction on the IVC may allow identification of lumbar vessels and aid in obtaining sufficient length for clip placement. Lower pole renal arteries may be encountered and should not be confused with lumbar vessels. The lymphatic tissue medial to the ureter is mobilized and excised. The underlying psoas fascia is preserved ( Fig. 119.9, A ). The inferior limit of dissection is reached with clear visualization of the common iliac artery and vein ( Fig. 119.9, B ).




FIGURE 119.4


Right-sided LRPLND. ( A , B ) Incision of the peritoneum, gonadal vein, and lymphatics.

( B , From Allaf ME. Laparoscopic retroperitoneal lymph node dissection. In Bishoff JT, Kavoussi LR, eds. Atlas of laparoscopic urologic surgery . Philadelphia: Saunders; 2007:238-249.)



FIGURE 119.5


Right-sided laparoscopic retroperitoneal lymph node dissection. ( A ) Excision of the gonadal vein. ( B ) Transection of the spermatic artery. IVC, Inferior vena cava.

( A , From Allaf ME. Laparoscopic retroperitoneal lymph node dissection. In Bishoff JT, Kavoussi LR, eds. Atlas of laparoscopic urologic surgery . Philadelphia: Saunders; 2007:238-249.)



FIGURE 119.6


Right-sided laparoscopic retroperitoneal lymph node dissection. The adventitia overlying the inferior vena cava (IVC) is incised from cranial to caudal.



FIGURE 119.7


Right-sided laparoscopic retroperitoneal lymph node dissection. Borders of the precaval and paracaval lymph node packet.

(From Allaf ME. Laparoscopic retroperitoneal lymph node dissection. In Bishoff JT, Kavoussi LR, eds. Atlas of laparoscopic urologic surgery . Philadelphia: Saunders; 2007:238-249.)



FIGURE 119.8


Right-sided laparoscopic retroperitoneal lymph node dissection. The lumbar vessels are identified, doubly clipped, and divided. IVC, Inferior vena cava.



FIGURE 119.9


Right-sided laparoscopic retroperitoneal lymph node dissection. ( A , B ) Continued dissection to the inferior limit. IVC, Inferior vena cava.


The interaortocaval (IAOC) dissection then proceeds cephalad to the inferior mesenteric artery ( Fig. 119.10 ). Postganglionic sympathetic fibers and the sympathetic chain may be identified adjacent to lumbar veins posterior to the IVC ( Fig. 119.11 ). It is imperative the surgeon be able to differentiate the more fibrous bands representing nerve tissue from lymphatics if a nerve-sparing procedure is to be performed. A laparoscopic atraumatic DeBakey forceps can be used to anteriorly retract the IVC, and the aspirator–irrigator is used for blunt dissection ( Fig. 119.12 ). Meticulous dissection with use of the “split-and-roll” technique is necessary in this region to free adjacent nodal tissue without disruption of the sympathetic chain fibers. Lymphatic vessels are clipped when encountered, and packets are gently drawn around nerve fibers. Lumbar veins and arteries encountered in the IAOC region are doubly clipped and divided. Great care should be taken to prevent avulsion of lumbar vessels during this maneuver. Additionally, lumbar vessels are commonly in close proximity to the origin of postganglionic sympathetic, and these should be identified before placement of clips. The preaortic nodes are excised with the anterior surface of the aorta exposed ( Fig. 119.13 ). The retrocaval and retroaortic lymph node packets are excised completely. Constant attention to the location of the renal artery and vein, bilaterally, is imperative. It is essential to rule out the presence of a retroaortic or circumaortic left renal vein on preoperative imaging to avoid inadvertent injury to these vessels and the nearby superior mesenteric artery (SMA). The cephalad extent of the completed paracaval, precaval, and IAOC dissections is represented. The right renal artery and left renal vein represent the cephalad extent of the IAOC dissection ( Fig. 119.14 ).


Jan 2, 2020 | Posted by in UROLOGY | Comments Off on Laparoscopic and Robotic Retroperitoneal Lymph Node Dissection

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