Laparoscopic and robotic-assisted laparoscopic pelvic lymph node dissection

Laparoscopic pelvic lymph node dissection (LPLND) was first described in 1991 and has since evolved from both a medical and a technical standpoint, particularly with the introduction of the robotic platform. Robot-assisted LPLND (r-LPLND) has allowed surgeons to take advantage of enhanced visualization and precise control of instruments to perform a superior operation for prostate and bladder cancer treatment and staging. There continues to be extensive debate regarding the extent of dissection templates in high-risk prostate cancer, as well as the role for PLND in the low-risk patient. As more predictive nomograms have been developed and it has been further established that patients with prostate-specific antigen (PSA) levels <10 ng/mL and Gleason scores < 7 are at a very low risk for lymph node involvement, some advocate for a more selective use of PLND. In addition, other surgeons advocate for wider, more aggressive dissection than the standard dissection template in patients with higher risk disease. There is greater consensus in the bladder cancer literature regarding the need for a more extensive dissection template to achieve an adequate therapeutic and diagnostic outcome after PLND.

Indications and contraindications

Most patients undergo LPLND or r-LPLND as part of a radical cystectomy or prostatectomy procedure. The rare instances in which patients may benefit from an independent PLND include scenarios in which patients are at a high risk for having metastatic prostate cancer and are deciding among local therapies alone (radiation, perineal prostatectomy, or cryotherapy), systemic therapy (hormonal therapy), and multimodal therapy. Unfortunately, cross-sectional imaging studies such as computed tomography (CT) and magnetic resonance imaging (MRI) have very low sensitivities for detecting lymph node involvement. Consequently, PLND remains the gold standard for lymph node staging. Therefore, patients with high-risk features, including Gleason scores ≥ 8, suggestion of extracapsular extension on digital rectal exam or MRI, PSA > 20 ng/mL, a positive seminal vesicle biopsy, or clinical stage T2 or higher, may benefit from a staging PLND before committing to radical prostatectomy with its associated morbidity.

r-LPLND is primarily performed in conjunction with robot-assisted laparoscopic prostatectomy based on the presence of preoperative risk factors of lymph node involvement. LPLND is also indicated in salvage procedures after failed radiation therapy, patients undergoing robot-assisted laparoscopic radical cystectomy, and rarely in patients with metastatic urethral and penile cancer.

Absolute contraindications to LPLND include bleeding diathesis, active infection, severe respiratory disease (chronic obstructive pulmonary disease), and severe coronary artery disease. Relative contraindications to LPLND are often related to surgeon experience. These may include extensive prior surgery in the lower abdomen and pelvis (inguinal hernia repair with mesh), morbid obesity, iliac artery tortuosity or aneurysm, history of inflammatory bowel disorders (extensive diverticulitis, perforated appendicitis, and inflammatory bowel disease), and patients with prior pelvic radiation.

Patient preoperative evaluation and preparation

Routine laboratory tests should be performed prior to a LPLND or r-LPLND, including a complete blood count, serum chemistry panel, coagulation studies, PSA, urinalysis, and urine culture. Another critically important aspect of the preoperative evaluation is to rule out any evidence of metastatic disease in the patient. Depending on the clinical indication, chest radiography, CT or MR imaging of the abdomen and pelvis, nuclear bone scan, ProstaScint scan (Cytogen Corporation, Princeton, NJ), prostate-specific membrane antigen, or Axumin PET/CT (Blue Earth Diagnostics Ltd., Oxford, UK) can be used to evaluate for the presence of metastatic disease. The patient is instructed to discontinue nonsteroidal antiinflammatory medications, aspirin, and any other anticoagulants with sufficient time prior to surgery to allow for return to normal coagulation. All appropriate medical and cardiopulmonary clearances should be obtained. The patient is instructed not to eat or drink after midnight the night before surgery. Preoperative bowel preparation is optional, though in our experience preferred, but may be more important in patients who have a history of prior abdominal surgery or inflammatory bowel disorders. The patient receives a perioperative dose of a first-generation cephalosporin antibiotic. Additional antibiotics with Gram-negative and anaerobic coverage should be considered if prostatectomy or cystectomy is to be performed.

Operating room configuration and patient positioning

Room configuration and patient positioning are, for the most part, similar for LPLND whether it is performed as an independent procedure or as part of a radical prostatectomy or cystectomy. There are slight room configuration differences depending on whether a laparoscopic or a robotic approach is being used.

When an LPLND is performed, the patient is placed in either the supine position or in a low dorsal lithotomy position with a full-length gel pad mattress placed underneath. If the dorsal lithotomy is chosen, careful attention is paid to minimize pressure along the lateral aspect of the knee where the common peroneal nerve lies. With the introduction of the da Vinci Xi robotic system, an r-LPLND can be performed in the dorsal lithotomy or supine position. Sequential compression devices are applied to the patient’s legs to minimize the risk of deep vein thrombosis (DVT). The arms are carefully tucked and padded along the patient’s side in the neutral anatomic position with the thumbs pointing towards the ceiling. Attention is paid to ensure that the arms and hands are under no traction or pressure. A urinary catheter is placed once the patient has been prepared and draped when a PLND is performed in conjunction with radical prostatectomy or cystectomy. If only a PLND is being performed, then a urinary catheter is placed prior to preparation and draping.

For LPLND the room is configured with the monitor at the foot of the bed between the patient’s legs ( Fig. 29.1 A). The surgeon stands on the left side of the patient, and the surgical assistant stands on the patient’s right side. For r-LPLND, with the patient in the dorsal lithotomy position, the robotic patient-side cart is docked in between the patient’s legs, the operating surgeon sits at the robotic console, and the assistant surgeon stands on the side of the patient where there is only one robotic arm being used ( Fig. 29.1 B). When utilizing the newer robotic platform, the patient can be positioned supine, with the robotic patient-side cart positioned at the patient’s side, while the assistant surgeon stands on the opposite side of the patient where there is only one robotic arm being used ( Fig. 29.1 C).

Trocar placement

After the patient has been prepared and draped in the standard sterile fashion, attention is turned towards obtaining peritoneal access. An 8- to 12-mm skin incision is made superior to the umbilicus. Using either a Veress needle or the Hasson technique, access into the peritoneal cavity is obtained. Pneumoperitoneum is established with carbon dioxide (CO ₂ ) to a pressure of 15 mm Hg. An 8-mm or 10/12-mm camera port is then placed through the supraumbilical incision. If an r-LPLND is being performed, the 30-degree robotic laparoscope in the down position is inserted through the umbilical trocar. Alternatively, if an LPLND is being performed, a 30-degree laparoscope is preferable. A brief survey of the pelvis is then performed to evaluate for any trocar placement injuries, the presence of any adhesions that may interfere with further port placement, and to identify the location of the iliac vessels as surgical landmarks.

The remaining port locations are based on whether an r-LPLND or LPLND is being performed. When a robot-assisted technique is used, our preference is to place an 8-mm robotic trocar approximately 7 to 8 cm (roughly one hand breadth) lateral to the level of the umbilicus on the right side. An additional 8-mm robotic trocar is placed one handbreadth further lateral on the right side, again at the level of the umbilicus. On the left side, a 10/12-mm assistant trocar is placed just superior to the level of the umbilicus approximately 6 to 7 cm from the midline. Finally, the third robotic 8-mm trocar is placed on the left side approximately 10 to 11 cm (one and a half handbreadths) lateral to the umbilicus. Depending on surgeon preference this port configuration for the r-LPLND can be flipped to the mirror image if the surgeon prefers to have the accessory robotic arm on the patient’s left side ( Fig. 29.2 A).