Extended lymphadenectomy in hilar cholangiocarcinoma: What it will bring?

Lymph node dissection is always a hot issue in radical resection of hilar cholangiocarcinoma (HCCA). There are still controversies regarding whether some lymph nodes should be dissected, of which the para-aortic lymph nodes are the most controversial. This review synthesized findings in the literature using the PubMed database of articles in the English language published between 1990 and 2019 on the effectiveness of extended lymphadenectomy including para-aortic lymph nodes dissection in radical resection of HCCA. Hepatobiliary surgeons have basically achieved a consensus that enough lymph nodes should be obtained to accurately stage HCCA. Only a very small number of studies have focused on the effectiveness of extended lymphadenectomy including para-aortic nodes dissection on HCCA. They reported that extended lymphadenectomy can bring some survival benefits for patients with potential para-aortic lymph node metastasis and more lymph nodes can be obtained to make the patient's tumor staging more accurate without increasing the related complications. Extended lymphadenectomy should not be adopted for HCCA patients with intraoperatively confirmed distant lymph node metastases. For these patients, radical resection combined with postoperative adjuvant chemotherapy seems to be a better choice. A prospective, multicenter, randomized, controlled clinical study of regional lymphotomy and extended lymphadenectomy in HCCA should be conducted to guide clinical practice. A standardized extended lymphadenectomy may help to more accurately stage HCCA. Future studies are required to further assess whether extended lymphadenectomy can improve long-term survival in negative celiac, superior mesenteric, and para-aortic lymph node diseases.