Radical Nephrectomy: Lymph Node Dissection

Abstract

When Alice E. Parker26 of Denver injected Baum’s modification of Gerota’s Prussian blue dye into the renal parenchyma of stillborn fetuses and adult cadavers in 1934 to study “the main posterior lymph channels of the abdomen and their connections with the lymphatics of the genitourinary system” she provided the anatomical basis for a debate that started several decades later and has continued for nearly half a century now: Although retroperitoneal lymph node dissection (LND) may provide more accurate pathological staging in the surgical management of renal cell cancer (RCC), the independent value of extended LND for all patients with RCC remains a highly controversial issue among urologists. While Robson’s original description of radical nephrectomy (RN) as the “gold standard” in the curative treatment of localized RCC included excision of the perinephric tissue, adrenalectomy, and “complete regional” lymphadenectomy (from the diaphragm to the aortic bifurcation),30 the therapeutic efficacy of the latter has been questioned repeatedly over time. Given the strong prognostic value of nodal status, one might expect a consensus for routine LND for this malignancy. In reality, RCC is the opposite extreme of testes cancer, where the pattern of lymphatic spread tends to be reliable, a beneficial effect of LND is proven, and the indications for LND are well defined. Significant advances in the diagnosis, staging, and treatment of patients with RCC during the past 20 years have not only resulted in improved survival of a select group of patients and an overall change in the natural history of the disease, but also altered the philosophical framework for the discussion regarding LND.20,28 Therefore, the role of LND must be critically reappraised in light of the steady increase in incidental detection of asymptomatic renal masses, the consecutive stage migration, and the shift toward nephronsparing surgery (NSS) and minimally invasive tissue ablative technology. Potential benefits to performing LND at the time of RN include more accurate pathological staging, removal of micrometastases, a lower risk of positive margins due to a more extensive dissection of perinephric tissue (leading to a lower risk of local recurrence), reduction of locoregional complications, cure in a select group of patients with metastatic disease limited to the resected nodes, and improved likelihood of a favorable response to systemic therapy in the setting of cytoreduction in advanced disease.20 The two subsequent key questions are whether there is any clinically relevant benefit of knowing lymph node metastasis (diagnostic value) and of the removal of lymph node metastasis (therapeutic value). This chapter examines the current indications and scope of LND in the surgical treatment of patients with RCC.