Retroperitoneal Lymph Node Dissection

Videos

• Open
  • Open transperitoneal RPLND (Cleveland Clinic, abbreviated)
  • Open transperitoneal RPLND (University of Chicago, abbreviated)
  • Open transperitoneal RPLND (Tata Memorial Hospital, abbreviated)
  • Open extraperitoneal RPLND (USC, abbreviated)
• Laparoscopic
  • Laparoscopic RPLND (Dr. Sergey Baydo, full video)
• Robotic
  • Robotic RPLND (Dr. James Porter, full video)
  • Robotic RPLND (Dr. James Porter, full video)

Classification of Retroperitoneal Lymph Node Dissection (RPLND)

• Primary RPLND
  • Performed after orchiectomy for CS I or low-volume CS II NSGCT with normal post-orchiectomy STMs
• Post-chemotherapy RPLND (PC-RPLND)
  • Performed after completion of induction systemic chemotherapy
  • Generally performed when there is a residual retroperitoneal mass and normal post-chemotherapy serum tumour markers. At some centers, PC-RPLND is performed even when there is a clinical complete remission (CR) to chemotherapy.
  • In general, patients with elevated STMs after induction chemotherapy should receive salvage chemotherapy.
    • Salvage PC-RPLND
      • Performed after completion of induction and salvage (standard or high-dose) chemotherapy.
    • Desperation PC-RPLND
      • Performed despite serum tumour marker elevation
    • Reoperative RPLND
      • Performed in a patient who has undergone prior primary RPLND or PC-RPLND
    • Resection of late relapse—PC-RPLND
      • Performed for retroperitoneal recurrence 24 months or later after CR to primary therapy (which may or may not have included RPLND).

Pre-operative planning

• Patients who are candidates for RPLND should be referred to an experienced surgeon at a high-volume center.
  • Surgeons with experience in the management of GCT and expertise in minimally invasive surgery may offer a minimally-invasive RPLND, acknowledging the lack of long-term data on oncologic outcomes with minimally-invasive approach.
• Principles of RPLND (template, limits, nerve-sparing, etc.) are applied, regardless of the intent to administer adjuvant chemotherapy or approach (open vs. minimally-invasive)
• Patients that have received bleomycin are at risk of post-operative respiratory distress syndrome; low fraction of inspired oxygen (FIO2) and conservative intraoperative fluid resuscitation are important in minimizing the risk of postoperative lung toxicity
  • Based on two studies, one from 1978 of 12 patients undergoing RPLND for testis cancer at MSK[1] (used t-test for statistics), and another from 1998 of 77 patients with previous bleomycin exposure undergoing “major surgical procedures” at MD Anderson[2]. The latter study found that in multivariate analysis, only amount of blood transfused, preoperative forced vital capacity and surgical time in descending order were significant. In univariate analysis, fluid balance, type of fluid given, among others were significant. Maintained intraoperative fractional inspired oxygen was not significant on either analysis.
• Identify renal arterial anatomy and possibility of accessory branches
• High-fat diet on night prior to surgery can facilitate identification of lymphatic vessels during surgery

Anatomic principles of RPLND[3]

• Relevant anatomy
  • Lumbar vessels[4]
    • See Figure
    • Arteries
      • Four, paired branches
        • 2nd–4th pairs commonly encountered below the level of the left renal vein
      • Regularly spaced
    • Veins
      • Variable, unpaired vessels
      • Preferentially drain into the left-posterior side of the IVC
      • Positioned at a distance from one another that segmentally increases closer to the iliocaval confluence
  • Aortic plexus[5]
    • Supplied by at least two lumbar splanchnic nerves on each side
    • Composed of two parallel nerves (cords), each containing two major ganglia
• Template
  • Full bilateral template
    • The boundaries of a full bilateral template include
      • Superiorly: the crura of the diaphragm and skeletonized renal vessels
      • Inferiorly: the bifurcation of the common iliac arteries/crossing of the ureter over the ipsilateral common iliac artery
      • Laterally: the ureters
      • This area includes the primary and secondary landing zones of the right (paracaval, interaortocaval) and the left (paraaortic, preaortic) testicle.
    • A full, bilateral template includes removal of the (10):
      1. Para-aortic
      2. Retro-aortic
      3. Pre-aortic
      4. Left common iliac
      5. Interoartocaval
      6. Pre-caval
      7. Para-caval
      8. Retro-caval
      9. Right common iliac lymph nodes
      10. Ipsilateral gonadal vessels
    • Indications (2019 AUA Guidelines)[6]
      • Absolute (2):
        1. Suspicious lymph nodes based on CT imaging or intraoperative assessment
        2. Somatic-type malignancy in the primary tumor.
           • Malignant transformation of teratoma is defined as the transformation of a somatic teratomatous component of a germ cell tumor (GCT) to a non-germ cell malignant tumor[7]. Examples of most common malignant transformation are sarcoma (e.g., rhabdomyosarcoma, osteosarcoma, chondrosarcoma, angiosarcoma, and liposarcoma), carcinoma (adenocarcinoma and squamous cell carcinoma), primitive neuroectodermal tumor, as well as hematologic malignancies[8].
      • Relative
        • Clinically negative lymph nodes.
  • Modified
    • Right modified template may omit the para-aortic lymph nodes below the inferior mesenteric artery.
      • Omission of para-aortic lymph nodes above the inferior mesenteric artery is controversial.
    • Left modified template dissection may omit paracaval, precaval, and retrocaval lymph nodes.
      • Omission of interaortocaval lymph nodes is controversial.
    • Indications
      • Relative
        • Clinically negative lymph nodes.
  • A complete retroaortic and/or retrocaval lymph node dissection with division of lumbar vessels should be performed when within the planned template.
  • The ipsilateral gonadal vessels should be removed in all patients.

Open RPLND Technique

• Videos
  • Open transperitoneal RPLND (Cleveland Clinic, abbreviated)
  • Open transperitoneal RPLND (University of Chicago, abbreviated)
  • Open transperitoneal RPLND (Tata Memorial Hospital, abbreviated)
  • Open extraperitoneal RPLND (USC, abbreviated)
• Position: supine
• Incision: ventral midline, from subxiphoid to pubis
• Steps after incision (transperitoneal):
  • Enter peritoneal cavity
  • Inspect abdominal viscera
  • Identify and divide the falciform ligament to minimize risk of hepatic retraction injury.
  • Place a self-retaining retractor, such as Bookwalter, Thompson, or Wishbone.
  • Expose retroperitoneum. Retract small bowel superiorly. Incise line of Toldt to medialize ascending colon. Make incision in posterior peritoneum from the cecum to the ligament of Treitz (suspensory muscle of duodenum). Medialize duodenum. Place bowel on chest. Place retractor.
  • Divide ("split") tissue anterior to IVC using cautery. Superior aspect of incision is the superior aspect of the left renal vein. Use clips on lymphatic tissue.
  • Para-caval packet. Identify right ureter and reflect it laterally. Identify right renal vein. "Roll" the IVC medially and develop the paracaval packet off the IVC (split and role technique). Remove all tissue anterior to the anterior spinous ligament from the right renal vein to the bifurcation of the IVC to include the right inguinal nodes.
    • This region is void of sympathetic nerves.
    • With the IVC rolled left, a variable number of lumbar veins (usually 2–3) may be encountered draining the right side.
      • Typically, the right superior lumbar vein (usually of large diameter) will be located near the right reno-caval junction, often superior to the right gonadal vein.
      • Midway along the infrarenal IVC, a smaller lumbar vein may be encountered that has a tendency to drain into the left side of the IVC or form a common trunk with one of the left-sided lumbar veins.
      • Lastly, the right inferior lumbar vein may be encountered draining near the level of the iliocaval confluence.
  • Identify the right gonadal vein. If right-sided disease, ligate at its insertion into the IVC. Dissect gonadal vein distally and excise right spermatic cord to internal inguinal ring. If left-sided disease, need to excise left spermatic cord to internal inguinal ring.
  • Inter-aortocaval packet. Use Kitner and Penfield to dissect packet. Remove all retroaortic and retrocaval tissue.
    • Using the split-and-roll technique on the IVC, the plane between the interaortocaval nodal tissue and the caval adventitia can be separated without encountering sympathetic nerves.
    • Lumbar vessels are encountered and may need to be ligated.
      • The left lumbar veins (variable) are often observed draining centrally (i.e., between the most cranial and caudal right lumbar veins) and into the left side of the IVC.
      • Usually, two left lumbar veins are observed; the largest and most prevalent of which (common lumbar trunk) may be landmarked using the IMA, and often receives multiple left-sided tributaries.
      • The second most common vessel, the left inferior lumbar vein, is located closer to the iliocaval confluence, approximately where the right common iliac artery crosses the IVC.
      • If a right inferior lumbar vein was present, the left is typically slightly rostral.
      • Once ligated, full control of the lumber veins should be achieved and the IVC can be fully mobilized
    • The right gonadal vein may be useful to approximate the location of the right superior lumbar vein (if present) and/or the 2nd pair of lumbar arteries. The IMA may be useful to approximate the location of the common lumbar trunk (if present) and/or the 3rd pair of lumbar arteries[9].
    • Identify post-ganglionic sympathetic nerves. Post-ganglionic sympathetic nerve fibers run posterior to the IVC and anterior to the aorta. With the right sympathetic chain exposed, meticulous dissection should be made anterior to identify the lumbar splanchnic nerves. Usually, there are two lumbar splanchnic nerves joining the infrarenal portion of the aortic plexus, spaced approximately one vertebral level apart. Dissect nerves free from interaortocaval packet.
    • Usually three pairs of lumbar arteries are present along the infrarenal abdominal aorta, with the position of the middle pair (3rd lumbar arteries) approximated using the origin of the IMA. Once identified, the adjacent pairs of lumbar arteries can be identified at a distance away equal to one third of the length of the infrarenal abdominal aorta
  • Divide ("split") tissue anterior to aorta using cautery. Superior aspect of incision is the superior aspect of the left renal vein. Use clips on lymphatic tissue. Identify and preserve IMA. To aid dissection, the IMA may be sacrificed if adequate blood supply to the colon is maintained by the marginal artery (of Drummond)
  • Para-aortic packet. Identify left ureter and reflect it laterally. Identify left renal vein. "Roll" the aorta medially and develop the para-aortic packet off the aorta. Identify inferior mesenteric vein. Identify lumbar arteries; strong tendency for paired lumbar arteries to be positioned at similar levels. Remove all tissue from the left renal vein to the bifurcation of the aorta to include the left inguinal nodes. The packet can be divided above vs. below the inferior mesenteric artery. Identify post-ganglionic sympathetic nerves. Dissect nerves free from para-aortocaval packet.
  • Obtain hemostasis.
  • Return small bowel to anatomic position.
  • Closure.
• Postoperative care
  • Alvimopan
  • Low-fat diet POD#2 and maintained for 30 days to reduce risk of chylous ascites

Use of modified template RPLND

• The relatively predictable pattern of the lymphatic spread of testicular GCTs provided strong pathologic evidence for the use of “modified bilateral” templates in patients with low-stage retroperitoneal disease.
• Potential advantages:
  • Decreased risk of loss antegrade ejaculation (from omission of the contralateral retroperitoneum and interiliac regions)
  • Decreased risk of chylous ascites, renovascular injuries, and pancreatic complications (from omission of suprahilar regions)
• Boundaries of the modified template vary by definition.
  • At Indiana, the recommended template for right‐sided tumours included the paracaval, precaval, inter‐aortocaval, pre‐aortic, right iliac and right gonadal regions. The template for left‐sided tumours included the para‐aortic, pre‐aortic, inter‐aortocaval, left iliac and left gonadal regions. Ultimately, Indiana’s modified templates eliminated dissection of the contralateral tissue below the inferior mesenteric artery, thereby sparing the lumbosacral sympathetic nerves, postsympathetic efferent nerves, and hypogastric sympathetic plexus.
• Suprahilar/retrocrural and interiliac resections can safely be omitted from the standard RPLND template. However, controversy exists regarding the need to resect the contralateral retroperitoneal lymphatic tissue.
• The standard PC-RPLND is resection of all macroscopic disease along with a full bilateral infrahilar dissection.

Nerve-sparing

• For successful antegrade ejaculation, several processes need to occur in coordinated fashion:
  1. Smooth muscle contraction in the vasa deferentia, seminal vesicles, and prostate resulting in seminal emission and prostate glandular secretion
  2. Closure of the bladder neck to prevent retrograde ejaculation
  3. Rhythmic contractions of the ischiocavernosus, bulbospongiosus, and levator ani muscles expelling semen from the urethra.
  • Processes 1 and 2 (emission and closure of bladder neck) require efferent neurologic input from the L1 through L4 postganglionic sympathetic fibers, which coalesce with their contralateral counterparts in the superior hypogastric plexus. From the hypogastric plexus, these nerve fibers continue caudally to the seminal vesicles, ampulla of the vasa deferentia, vasa deferentia proper, bladder neck, and prostate
• Nerve-sparing should be offered in select patients desiring preservation of ejaculatory function.
• Nerve-sparing RPLND results in preservation of antegrade ejaculation in 90-100% of patients
• Nerve-sparing should not compromise the quality of the lymph node dissection.

Minimally Invasive RPLND

• Rationale and Evolution
  • Potential advantages of MIS approach vs. open RPLND: decreased blood loss, shorter hospital stays, and faster return to normal activity
    • The reduced recovery allows patients who are candidates to receive chemotherapy with minimal delay.
  • MIS approach can allow preservation of antegrade ejaculation in > 95% of patients, similar to nerve-sparing open RPLND
• Staging Laparoscopic RPLND and controversy
  • Previously, L-RPLND was used as a staging procedure; if staging found absence of occult metastases, those patients were spared exposure to chemotherapy without undergoing open RPLND. When used for staging, a limited dissection was performed with the use of restrictive templates and omission of the retrocaval or retroaortic lymph nodes.
  • Use of L-RPLND has been abandoned and has evolved into a therapeutic procedure duplicating the open approach (wide templates and complete excision of retroaortic and retrocaval tissue) in its intent
• Surgical technique
  • Indications for primary L-RPLND are identical to the indications for open RPLND. In the post-chemotherapeutic setting, L-RPLND has been limited mainly to small-volume residual disease; however, experienced surgeons have excised bulky tumors
  • Preoperative patient preparation and technical considerations
    • All patients considered candidates for L-RPLND must be fully informed of all treatment options, including open RPLND, chemotherapy, and surveillance.
    • Potential complications include bleeding requiring blood transfusion; injury to adjacent organs (liver, bowel, gallbladder, kidney, ureter, pancreas, major vascular structures); and orthopedic, neurologic, or pulmonary complications as well as conversion to open surgery because of complications or incomplete resection
    • Patients interested in future fertility are educated regarding preoperative sperm banking
    • Patients undergo a mechanical bowel preparation the afternoon before surgery and take only clear liquids until midnight to decompress the bowels.
  • Approach
    • Most prefer a transperitoneal approach
• Postoperative care
  • The patient may ambulate and resume a liquid diet the night of surgery.
  • Postoperative tachycardia may occur secondary to sympathetic stimulation
  • Most patients can be discharged on postoperative day 1.
• Prospective nerve-sparing techniques
  • As in open RPLND, nerve-sparing techniques involve prospectively identifying, dissecting, and preserving the sympathetic chains, hypogastric plexus, and postganglionic fibers. With experience, these tissues can be readily identified as more fibrous compared with lymphatic tissue.
  • On the right side, the postganglionic sympathetic fibers are most easily identified behind the IVC as they cross anterior to the aorta to insert in the hypogastric plexus. Their takeoff from the sympathetic chains is always near lumbar veins, so great care should be taken in clipping lumbar vessels.
  • On the left side, the postganglionic sympathetic fibers are most easily identified at the ganglia as they leave the sympathetic chain and dissect them prospectively as they course anterior to the aorta before joining the hypogastric plexus.
  • Care should be taken to avoid energy sources such as electrocautery when dissecting nerve fibers
• Adverse Events
  • Postoperative complication rates of 9-25%
  • Potential complications include chylous ascites, ileus, lymphocele, nerve injury, pulmonary embolus, Clostridium difficile colitis, retroperitoneal hematoma, and ureteral injury
  • Intraoperative bleeding is still the most commonly reported complication of the laparoscopic RPLND
  • With meticulous ligation of lymphatic channels, the incidence of chylous ascites should be < 2%.
  • The rates of retrograde ejaculation have been consistently low with the laparoscopic approach and range from 0-14%
  • Open conversion rate is < 5%, but it has been reported as high as 11.8%; the most common reason for conversion to an open procedure is bleeding
  • Injury to major abdominal viscera also has been reported but appears to be a rare event
  • The morbidity and open conversion rate of L-RPLND after chemotherapy is higher
• Results and current status
  • Laparoscopic RPLND for clinical stage I disease
    • Published reports of L-RPLND with long-term follow-up suggest that it is an effective treatment option for patients with low-stage NSGCTs
    • Reports omitting chemotherapy for patients with N1 disease who underwent L-RPLND support its therapeutic efficacy, but more studies and follow-up are required
  • Laparoscopic RPLND for clinical stage II disease
    • Fewer reports exist examining the role of L-RPLND for patients with clinical stage II NSGCTs as a primary modality or in the postchemotherapeutic setting

Chylous ascites

• Refers to the accumulation of chylomicron containing lymphatic fluid in the peritoneal cavity.
• Occurs in 0.2-2% of patients undergoing primary RPLND and 2-7% of patients undergoing PC-RPLND
• Management options (5):
  1. Paracentesis
  2. Low-fat/medium-chain triglyceride diet
  3. Somatostatin/octreotide.
  4. Indwelling drain
  5. Total parenteral nutrition

Auxiliary procedures

• Nephrectomy is the most commonly performed auxiliary procedure at the time of PC-RPLND
  • Nephrectomy is usually needed in high-risk settings such as salvage RPLND, desperation RPLND, resection of late relapse, or reoperative RPLND.
• Inferior vena cava resection
  • Most cases requiring IVC resection have bulky stage disease (stage IIb or higher).
• Aortic resection and reconstruction
• Hepatic resections
• Pelvic resections

References

• Wein AJ, Kavoussi LR, Partin AW, Peters CA (eds): CAMPBELL-WALSH UROLOGY, ed 11. Philadelphia, Elsevier, 2015, chap 35
• Wein AJ, Kavoussi LR, Partin AW, Peters CA (eds): CAMPBELL-WALSH UROLOGY, ed 11. Philadelphia, Elsevier, 2015, chap 36
• Stephenson, Andrew, et al. "Diagnosis and treatment of early stage testicular cancer: AUA guideline." The Journal of urology 202.2 (2019): 272-281.
• Beveridge, Tyler S., et al. "Retroperitoneal lymph node dissection: anatomical and technical considerations from a cadaveric study." The Journal of urology 196.6 (2016): 1764-1771.[10]