What is considered adequate pelvic lymphadenectomy for bladder cancer and is there a therapeutic benefit in LN positive disease? Smith and Whitmore demonstrated that the obturator and external iliac lymph node regions were the most common sites for lymph node metastases at 74 and 65 %, respectively [11]. Additionally in this study it was found that 19 % of positive lymph nodes were along the common iliac chain. This was one of the first studies indicating that a standard lymph node dissection was likely an inadequate for removal of regionally involved lymph nodes. Leissner et al. performed a study in 447 patients who underwent pelvic lymphadenectomy and found that there was a statistically significant survival advantage in patient who underwent a more extended lymphadenectomy with equal or greater than 16 lymph nodes removed [5]. There was a significant correlation between the number of lymph nodes removed and the 5-year cancer-specific survival in pT1-3 tumors. In a later multicenter study by Leissner et al. that involved 290 patients who underwent radical cystectomy with extended pelvic lymphadenectomy found that approximately 28 % have positive lymph nodes and the percentage of metastases at different sites range from 14.1 % in the right obturator nodes to 2.9 % in the para-caval nodes above the aortic bifurcation [6]. Their analysis found that the incidental LN metastases was 21 % for nodes inferior to the bifurcation of the common iliac artery and 18.6 % at the common iliac and presacral nodes. They also showed that 10 % of primary sites of lymphatic spread were at the common iliac nose, and tumor spread to the contralateral side of the pelvic nodes was also found. They also report reported that 16.5 % of lymph node positive metastases were found between the level of the IMA and the aortic bifurcation suggesting the necessity for dissection of this region especially for the purpose of staging. However, a separate study by Zehnder et al. compared the extended lymphadenectomy data from Skinner’s series at the University of Southern California which included superior boundary of the IMA to the University of Bern with the boundary being the uretero–iliac crossing [12]. The USC group compared to the University of Bern group had a higher number of lymph nodes taken (38 versus 22, p < 0.0001) and a higher incidence of lymph node metastases (35 versus 28 %, p = 0.02). However, patient survival and recurrence was almost equivocal between these two large institutions suggesting no additional survival benefit from dissecting more cranial than the level of the ureteroiliac crossing at the common iliacs. Thus, the cranial extent of the dissection remains controversial in regard to survival.

Many authors have made the argument about the increased potential for staging with ePLND in regard to stratification of patient who may need adjuvant chemotherapy after surgery. However, to date there is no level I evidence that strongly supports adjuvant chemotherapy affecting survival in the postoperative setting. However a small retrospective series from Steinberg et al. that demonstrated that patients with lymph node metastases who received chemotherapy lived six times longer than patient who did not receive chemotherapy (48 versus 8 months, p < 0.0001) [13]. The benefit of adjuvant chemotherapy remains controversial; however, extended staging lymphadenectomy may be important for identifying patients at high risk patients for recurrence. The incidence of patients with nodal positive disease likely increases with a total of number of lymph nodes removed [12]. USC popularized the concept of lymph node density, which was defined as the total number of positive lymph nodes divided by the total number of lymph nodes taken. Lymph node densities greater than 20 % demonstrated an increased risk of death versus patients with a lymph node density less than 20 % (17 versus 43 % 10-year recurrence-free survival) [14]. It has been well established in the literature that the number of lymph nodes that will be reported is dependent on the pathologic processing [15–17]. A number of studies have demonstrated that increased node counts will be reported along with increased positive node detection with the increased number of specimens packet sent [15–17]. There is the potential concern that extended lymph node dissection increases the potential complication rate with radical cystectomy. Brössner et al. performed a prospective study looking at 92 consecutive patients who underwent radical cystectomy with 46 undergoing a standard LND versus 46 undergoing an extended LND. There was no difference in 30-day morbidity between the two groups. The extended lymphadenectomy clearly increases the operative time; however, this is not translated to increase morbidity or mortality in the literature [18]. Nevertheless, the oncologic gains from the extended template must be balanced against the additional time required that may relate to overall anesthetic time and subsequent thromboembolic risk, accumulation of lymphoceles, risk for vascular injury, and temporary or permanent lower extremity edema.