[The Role of Kidney-Sparing Surgery for Patients with Upper Tract Urothelial Carcinoma].

With the advancement of modern ureteroscopes and laser technology, kidney-sparing surgery(KSS)has an expanding role for patients with upper tract urothelial carcinoma(UTUC), although radical nephroureterectomy remains the gold standard. Patients with UTUC are generally elderly and often have major medical comorbidities. As such, KSS is recommended for patients with imperative indications, such as bilateral disease, renal insufficiency, or a solitary kidney, while maintaining renal function, resulting in the avoidance of potential long-term cardiovascular morbidity and hemodialysis. In addition, KSS is also advocated for low-risk patients(elective indication)based on the risk stratifications recommended by each guideline. The big issue of risk stratifications is their narrow indications at the cost of providing accuracy, but the current elective indications have been updated and expanded year by year. KSS includes endoscopic management through antegrade or retrograde access to the upper tract and segmental ureterectomy. Thulium: YAG laser in combination with Ho: YAG laser is recently used for KSS due to the advantages of its shallow penetration depth in tissue, with a reduced risk of upper urinary tract perforation. The concern regarding KSS is a high recurrence rate. Adjuvant intracavitary instillation to the upper tract has the potential to reduce the risk of recurrence. The phase Ⅲ trial assessing a mitomycin-containing reverse thermal gel (JelmytoTM)revealed the promising result despite their use not being approved in Japan. Therefore, KSS is assumed to have an increasing demand for patients with UTUC in our aged society and is expected to be widely utilized nationwide.