Retroperitoneal lymph node dissection for metastatic testicular cancer

Introduction

Retroperitoneal lymph lode dissection (RPLND) forms an integral part of the multidisciplinary management of testicular cancer. ^, Cisplatin-based chemotherapy regimens have revolutionized the treatment of testicular cancer, and consequently the role of surgery has changed. However, their combined role has resulted in overall survival rates over 90%.

Robot-assisted RPLND is increasingly being used in selective cases for stage 2 disease in both the primary and the postchemotherapy setting and has been described previously. ^,

Indications and contraindications for robot-assisted retroperitoneal lymph node dissection

There are some geographical variations in the indications for RPLND between North America and Europe, particularly for primary RPLND in nonseminomatous germ cell tumor. In North America, primary RPLND is offered in high-risk stage 1 nonseminomatous germ cell tumor and stage 2A and 2B nonseminomatous germ cell tumor. Primary RPLND is increasingly being recommended for stage 2A disease in Europe. Universally, RPLND is recommended for residual masses greater than 1 cm after chemotherapy where tumor markers have normalized or in the event of retroperitoneal relapse with normal markers. RPLND is also being utilized in the trial setting for stage 2 seminoma prior to any chemotherapy.

There are no absolute indications for a robot-assisted approach specifically. Table 29.1 lists factors that should be considered in determining whether robot-assisted RPLND may be feasible. As most robot-assisted approaches only allow dissection from a limited number of directions, the size of the mass should be small enough to enable adequate exposure of the mass. A threshold of 5 cm could be used as a guideline from this perspective. The relationship of the disease to the great vessels is perhaps the most important consideration with circumferential adherence/contact being a contra-indication. Predominance of disease that is posterior, especially retroaortic or retrocaval, will be more difficult to dissect, and any vascular injury will be more difficult to repair. Masses that have shrunk significantly after chemotherapy tend to be more fibrotic and hence can be more challenging to dissect than larger cystic masses with a well-defined border. Dissection is also more difficult in patients who have had multiple lines of chemotherapy. ^,

Table 29.2 lists relative and absolute contraindications to robot-assisted RPLND. For robot-assisted RPLND, there must be surgical expertise available to perform an open RPLND in the event of conversion and also vascular surgical expertise for vascular control and repair. Table 29.3 lists advantages and disadvantages of the robot-assisted approach as compared to the open approach.

Preoperative assessment

All cases considered for RPLND should be discussed in a multidisciplinary setting. If surgery is recommended, surgical planning should begin with extensive review of the patient’s most recent cross-sectional imaging and any previous imaging, particularly prechemotherapy imaging. A decision regarding unilateral or bilateral template dissection should be made based on institutional policy as there remains significant conjecture regarding suitability of unilateral templates, particularly in the postchemotherapy setting.

The relationship of the disease to the renal vessels and ureters should be assessed. Preoperative ureteric stenting may be helpful if the ureters appear densely adherent to the retroperitoneal disease. Assessment of the proximity of retroperitoneal disease to the duodenum and great vessels should be made to determine if specialty assistance from a vascular surgeon or general surgeon may be required.

Routine blood tests should be performed preoperatively to assess the patient’s baseline renal function and also to assess whether hematological parameters have returned to the normal range after previous chemotherapy. If bleomycin was given as part of the chemotherapy regimen, respiratory assessment should be made to determine if additional measures are required peri-operatively such as preoperative steroids and anesthetic management of intraoperative ventilation. Blood grouping should be done to ensure there is adequate facility for urgent transfusion in the event of unexpected hemorrhage.

Theater and port setup

See Table 29.4 for special equipment required and for operating room setup, Fig. 29.1 for unilateral template, and Fig. 29.2 for bilateral template.

For the borders of the templates, see Fig. 29.4 A (left unilateral template), Fig. 29.5 A (right unilateral template), and Fig. 29.6 A (bilateral template).

Left unilateral template

Positioning

After induction of general anesthesia, a Foley catheter is placed prior to positioning the patient in the right lateral position in a similar manner to a left robot-assisted nephrectomy or nephroureterectomy (see Fig. 29.1 A). The bed should be flexed to open up the left lateral aspect of the abdomen. Lateral supports should be placed to support the patient’s back. The arms should be flexed at the elbows with the shoulder at 90 degrees. The left leg should be straight with the right leg flexed. Gel pads or supports should be placed at the right ankle and right knee to minimize neuropraxia. A urethral catheter should be inserted. A nasogastric or orogastric tube should be in place intraoperatively to decrease any gastric distension for safe port placement.

Stages of the procedure

Port placement.

A linear configuration of ports is used similar to a left nephroureterectomy with the four 8 mm robotic ports placed along the left linea semilunaris when using the da Vinci Xi. The camera port is inserted using a Hasson technique and pneumoperitoneum is then established at 12 mmHg. The remaining ports are inserted under vision. The 12 mm assistant port is placed in between the middle two ports. If a difficult dissection around the renal vessels is anticipated, it may be worth considering placing the assistant port in the midline between the superior two ports (see Fig. 29.1 A). For the da Vinci Si or X, it may be worth moving the inferior 8 mm robotic port 3 cm laterally to minimize clashes.

Robot docking.

The robot is docked with the second most superior robotic port being the camera port. For the da Vinci Xi, targeting is performed with the target being the predicted para-aortic region inferior to the left renal vessels. The remaining ports are then docked (see Fig. 29.1 C).

A fenestrated bipolar forceps is placed in the superior robotic port, monopolar scissors in the second-most inferior robotic port and a ProGrasp forceps in the inferior robotic port. A 0-degree scope is used; however, a 30-degree downward scope may be necessary for the medial aspects of dissection.

Dissection

Descending colon mobilization.

The descending colon is mobilized by an incision along the line of Toldt from the splenic flexure to the left aspect of the pelvis inferior to the iliac vessels ( Fig. 29.3 A). Gerota fascia over the left kidney should be left intact at this time. The spleen can be mobilized more medially by extending the incision in the posterior peritoneum inferior to the spleen toward the diaphragm. This should enable appropriate exposure of the left renal hilum (see Fig. 29.3 B).

Left ureter identification.

The left ureter is identified during mobilization of the descending colon and then retracted laterally using the ProGrasp. This should allow exposure of the left psoas muscle posteriorly. Too much tension on the left ureter should be avoided to prevent devascularization of its tenuous blood supply. The medial aspect of the left ureter can then be dissected to the renal pelvis superiorly and to the crossing of the left common iliac artery inferiorly—this represents the lateral border of the template. The left gonadal vein will be lateral to the ureter in the inferior aspect of this region and will be more medial to the ureter where it joins the left renal vein (see Fig. 29.3 C and D).

Para-aortic dissection.

The template dissection is commenced at the point where the left ureter crosses the left common iliac artery ( Fig. 29.4 A). A tissue packet is isolated from these structures and dissection continues superiorly by dissecting the tissue packet off the psoas muscle posteriorly and the left common iliac artery medially (see Fig. 29.4 B). As the dissection progresses, the tissue packet is dissected laterally off the aorta. The inferior mesenteric artery will arise from the anterior aspect of the aorta and will pass to the patient’s right due to the descending colon having been mobilized. Posteromedially, lumbar arteries and veins may be encountered and should be clipped with Hem-o-loks or clips and divided. Dissection proceeds along the aorta until the left renal vein is reached. The tissue packet is then dissected inferiorly off the left renal vein (see Fig. 29.4 C). The left gonadal vein should be clipped and divided as it enters the left renal vein. The dissection should then be completed with the dissection along the left renal vein joining the previous dissection of the left ureter. The left gonadal vein should be dissected to the left deep inguinal ring and clipped and divided to enable its complete excision (see Fig. 29.4 A). The specimens can then be placed in an Endocatch bag.

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