Lymph node dissection during nephroureterectomy: Establishing the existing evidence based on a review of the literature

Oncological outcomes of retroperitoneal lymph node dissection during retroperitoneal laparoscopic radical nephroureterectomy for renal pelvic or upper ureteral tumors: Matched-pair analysis

OBJECTIVES

To investigate the oncological outcomes and recurrence patterns of clinically node-negative patients with renal pelvic and/or upper or middle ureteral tumors after a template-based retroperitoneal lymph node dissection (RPLND) in conjunction with retroperitoneal laparoscopic radical nephroureterectomy (LRNU).

METHODS

A total of 283 patients who received LRNU with and without RPLND at three Japanese institutions were enrolled. The template of RPLND included the renal hilar and paraaortic lymph nodes (LNs) (left side) and renal hilar, paracaval, retrocaval, and intra-aortocaval LNs (right side). The LNs and kidneys were removed en bloc. The primary endpoint was set as recurrence-free survival. All RPLND cases were matched one-to-one with no RPLND cases using a propensity score matching approach, and 47 matched pairs were included in analyses.

RESULTS

Compared to the control group, significant differences were not observed in the RPLND group in terms of operation time, blood loss, postoperative complication rate, and pathological findings. The estimated five-year recurrence-free survival was significantly higher in the RPLND group (86.8%) compared to the group without RPLND (64.2%) (p = 0.014). The estimated five-year cancer-specific survival showed a similar tendency; however, it did not reach a statistically significant difference (87.5% vs 71.3%, respectively; p = 0.168). As for the first recurrence site, the RPLND group showed a lower incidence of distant recurrence, while a significant difference was not observed in the rate of regional LN recurrence.

CONCLUSION

This study suggests that a template-based RPLND in conjunction with retroperitoneal LRNU efficiently improves the recurrence-free survival by reducing distant recurrences.

Complications and their management following retroperitoneal lymph node dissection in conjunction with retroperitoneal laparoscopic radical nephroureterectomy

OBJECTIVES

To describe the detailed perioperative complications and their management after retroperitoneal lymph node dissection with retroperitoneal laparoscopic radical nephroureterectomy for patients with upper tract urothelial carcinoma at three institutions.

METHODS

Retroperitoneal lymph node dissection was performed on patients with upper tract urothelial carcinoma located at the pelvis and/or upper or middle ureter, and its template included the renal hilar and para-aortic lymph nodes (left side) and the renal hilar, paracaval, retrocaval, and intra-aortocaval lymph nodes (right side). The lymph nodes and kidneys were removed en bloc. The primary endpoint was postoperative complication rates, and the secondary endpoints were intraoperative findings and chylous leakage management. The associations of retroperitoneal lymph node dissection with postoperative complications were examined using logistic regression with propensity score techniques.

RESULTS

Eighty-eight (31%) and 195 (69%) patients underwent and did not undergo retroperitoneal lymph node dissection, respectively. There was no significant difference in postoperative complications and other perioperative findings in the entire cohort, except for prolonged operation time. Retroperitoneal lymph node dissection was not statistically significantly associated with total and serious complications in propensity score analyses. Postoperative chylous leakage could be conservatively managed even though it is common in patients with retroperitoneal lymph node dissection (14/88 (16%)). The incidence of chylous leakage was significantly lower in patients whose lymphatic vessels were meticulously clipped completely during retroperitoneal lymph node dissection (5.3% vs 24%; P = 0.017).

CONCLUSION

There was no association between retroperitoneal lymph node dissection with laparoscopic radical nephroureterectomy and postoperative complications. However, chylous leakage is often observed after retroperitoneal lymph node dissection and careful management is highly required. The use of clips during retroperitoneal lymph node dissection is recommended to minimize chylous leakage risk.

Survival Benefits Based on the Number of Lymph Nodes Removed during Radical Nephroureterectomy for Upper Tract Urothelial Carcinoma: Systematic Review and Meta-Analysis

The role of lymph node dissection (LND) is still controversial for upper tract urothelial carcinoma (UTUC), and there are no guidelines regarding its use. This study was conducted to find a higher level of evidence for the survival benefits based on the number of LNs removed during radical nephroureterectomy (RNUx) through a systematic review and meta-analysis. We included studies comparing patients who underwent LND during RNUx for UTUC. We searched the major electronic databases (Pubmed, Embase^®, and Scopus^®) and conducted manual searches of the electronically available abstracts of the major international urology cancer meetings [American Society of Clinical Oncology (ASCO), American Urological Association (AUA), and Eropean Association of Urology (EAU)] prior to April 2019 using grouped terms of nephroureterectomy (nephroureterectom*) and lymph node excision (lymphadenectomy; lymph + node*; lymph* + metasta*) with variations in the terms. Study selection, data collection, and risk of bias assessment were performed by two independent authors (A and B). Six retrospective case-control studies included a total of 33,944 patients who underwent RNUx for UTUC, 5071 of whom underwent LND and were finally included in the meta-analysis. The pooled hazard ratio (HR) in these studies revealed that an increased number of LNs removed during RNUx was associated with improved cancer-specific survival (CSS) in patients with UTUC (HR = 0.95, 95% CI: 0.91–0.99; p = 0.07). In addition, increased numbers of LNs removed were associated with improved overall survival (OS) in pN0 patients. However, in pN+ patients, the number of LNs removed showed no survival benefit on CSS, overall survival (OS), or progression-free survival (PFS). Higher numbers of LNs removed during RNUx were associated with improved survival outcomes in patients with UTUC. This study confirmed that LND also has oncological benefits in UTUC patients. Although still a controversial topic, meticulous LND must be considered, and efforts should be made to eliminate as many LNs as possible when administering RNUx for UTUC, especially in patients without clear evidence of LN metastasis.