Retroperitoneal Lymph Node Dissection

Retroperitoneal Lymph Node Dissection



The contemporary management of testicular germ cell tumors (GCTs), which incorporates significant advances in imaging, surgery, chemotherapy, and radiation therapy, has achieved high cure rates for this disease. But optimal outcomes for individual patients are highly dependent on nuances of management, underscoring the great importance of delivering the appropriate therapy, properly, and in the correct sequence (1). Failures of accurate staging, disciplined surveillance, and optimal treatment can lead to compromised chances for cure, long-term morbidity, and death.

Retroperitoneal lymph node dissection (RPLND) plays a key role in the management of testis cancer. When performed appropriately, it provides invaluable staging information, critical insight into tumor biology, and eradicates primary, chemorefractory, and potential sources of secondary cancers. Staging and prognostic information can be obtained through RPLND that exceed that of current imaging modalities. Standard axial imaging with computerized tomography (CT) or magnetic resonance imaging (MRI) understages 20% to 25% of patients with clinical stage (CS) I and overstages 15% to 35% of patients with CS IIA nonseminomatous germ cell tumor (NSGCT) (2,3). RPLND also plays a critical role as a therapeutic modality. In patients with low-stage NSGCT, cure rates approach 99% (4,5,6). In cases where the burden of retroperitoneal disease is low (pN1), RPLND monotherapy achieves cure in 90% of cases without additional chemotherapy, reduces the risk of retroperitoneal relapses to <2%, and reduces the burden of routine surveillance imaging (6,7). Although cure rates decline to <50% when RPLND is performed for higher volume disease (pN2), two cycles of adjuvant chemotherapy increases the cure rate to >98% (6,8,9). Suboptimal RPLND can result in increased relapse rates, late relapses, reoperative surgery, and decreased survival rates (10,11,12). Patients who must undergo reoperative retroperitoneal surgery after incomplete initial resections pay a particularly high price. After primary RPLND, reoperative RPLND leads to a 5-year disease-specific survival decrease from 99% to 86% (10). In the postchemotherapy setting, the 5-year disease-specific survival falls from 90% to 56% for patients requiring reoperative surgery (10).


Most GCTs spread lymphatogenously in a predictable sequence from their sites of origin in the testis. Metastases usually occur in well-defined regions of lymph nodes in the retroperitoneum, subsequently progressing to thoracic sites in the lung, posterior mediastinum, and then to involve distant visceral organs (13). Distant metastases, without concomitant retroperitoneal disease, are rare (6). The contemporary understanding of testicular lymphatic drainage was established by important RPLND mapping studies performed by Donohue et al. (14), Weissbach and Boedefeld (15), and Ray et al. (13). Anatomic regions were described along with the most common landing zones for tumors that arise from the left or right testicle (Fig. 61.1). Right-sided testicular tumors disseminate initially to the interaortocaval, precaval, and preaortic nodal groups and have the ability to spread to contralateral lymphatic sites (13,16,17). The landing zone of left-sided tumors includes the para-aortic and preaortic lymph nodes, with a low incidence of contralateral spread (13,6,15,16).

The standard bilateral RPLND includes the following boundaries: the renal vessels superiorly, the ureters laterally, the bifurcation of the iliac vessels inferiorly, and the prevertebral and psoas fascia posteriorly (Fig. 61.2). Although the early development of the RPLND included dissection of the suprahilar lymph nodes bilaterally, this has been shown to significantly increase chylous ascites and renovascular and pancreatic complications, with minimal oncologic benefit (4). Given the improvements in imaging, this element of the dissection is now omitted, except where known suprahilar disease exists in the postchemotherapy setting. Suprahilar metastases do occur, with the most common site of involvement the nodes of the retrocrural space (18).


Disruption of autonomic nerves in the retroperitoneum can lead to the loss of antegrade ejaculation, a complication that was noted in up to 90% of patients early in the development of the RPLND (19). The paired sympathetic chains along with their sympathetic ganglia, the postganglionic sympathetic fibers from T2 to L4, and the hypogastric plexus are essential in the process of seminal emission (Fig. 61.3). To decrease the risk of ejaculatory dysfunction, modified RPLND templates were developed based on retroperitoneal mapping studies (1,13,6,20,21). These templates altered the boundaries of the standard bilateral RPLND to minimize disruption to the hypogastric plexus and contralateral postganglionic sympathetic nerves below the inferior mesenteric artery (IMA) (Fig. 61.4). Although early reports suggested sustained oncologic outcomes, more recent studies reveal that modified template dissections could potentially miss a significant proportion of retroperitoneal metastatic disease. In a cohort of 500 patients with CS I or IIA NSGCT who underwent primary RPLND at Memorial Sloan-Kettering Cancer Center, the distribution of positive lymph nodes was analyzed and compared using five different modified template schemes (22). Depending on the template applied, 3% to 23% of metastases would be missed if a modified template was used (20). Moreover, 56% of these patients received adjuvant chemotherapy, which may have masked unresected disease and led to underestimation of the true rate of extratemplate disease. If all patients underwent full bilateral template resection, the rate of unresected disease would fall to below 3% (22,23). In a similar study of 269 patients who underwent postchemotherapy RPLND (PC-RPLND) for advanced disease, 7% to 32% of patients harbored extratemplate disease (24). These reports support the use of full, bilateral, infrahilar RPLND and suggest modified templates may inadequately treat the retroperitoneum. This leads to an increased burden of postsurgery surveillance, higher rates of postsurgery chemotherapy, and inferior long-term oncologic outcomes (21,23).

FIGURE 61.1 Anatomic regions of the retroperitoneal lymph nodes.

FIGURE 61.2 Boundaries of full-template RPLND. The renal vessels form the superior boundary, the ureters form the lateral boundary, and the bifurcation of the iliac vessels forms the inferior boundary. IMA, inferior mesenteric artery; IVC, inferior vena cava; SMA, superior mesenteric artery.


With advancements in the understanding of the neuroanatomic basis of seminal emission and ejaculation, critical nerves can be prospectively identified and spared without compromising
the boundaries of resection. Each vas deferens and seminal vesicle is innervated by postganglionic sympathetic nerve fibers arising from the sympathetic chain from T12 to L3. The right sympathetic chain lies directly posterior to the inferior vena cava (IVC), whereas the left sympathetic chain lies posterior to the lateral border of the aorta (see Fig. 61.4B).

FIGURE 61.3 Schematic of retroperitoneal nerves. A: The sympathetic fibers innervating responsible for seminal emission emerge as postganglionic fibers from T12 to L3. The paired sympathetic trunks lie on the medial borders of the psoas muscle bilaterally. Fibers converge on the anterior surface of the aorta to form the inferior mesenteric and hypogastric plexuses. B: The right sympathetic trunk lies posterior to the IVC, and the left sympathetic trunk lies near the lateral border of the aorta. The lumbar branches of the great vessels run closely with the nerves and course medial to the sympathetic trunks as they course toward the vertebral foramina.

FIGURE 61.4 Right and left modified templates for RPLND. Several side-specific modified templates for patients with low-stage NSGCT have been proposed, with each including ipsilateral lymph nodes inferior to the renal hilum extending to the bifurcation of the iliac arteries. Right-sided templates include the interaortocaval region, and both avoid dissection below the contralateral IMA.

The postganglionic fibers emerge anterolateral to the lumbar vessels, from the lumbar foramina. The lumbar vessels emerge medial to the sympathetic trunks. Nerves from the right sympathetic trunk course from the medial border of the IVC anterolaterally over the aorta and converge with fibers from the left sympathetic trunk to form the plexus of nerves on the anterior surface of the aorta, including the hypogastric plexus. Due to this anatomic arrangement, dissection of the lymph nodes over the aorta, or the anterior aortic split, should be performed after the nerve fibers have been identified and isolated to prevent their unintended disruption (Fig. 61.5). After meticulous dissection, the sympathetic chains, the postganglionic sympathetic fibers, and the hypogastric plexus are preserved. This approach has yielded a postoperative return to antegrade ejaculation in 95% of patients undergoing primary RPLND and 79% in postchemotherapy RPLND (25,26,27,28).

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Apr 24, 2020 | Posted by in UROLOGY | Comments Off on Retroperitoneal Lymph Node Dissection
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