Category: Basic Science: Stones

MP8-22 - Outcomes of long-term follow-up of asymptomatic renal stones and prediction of stone related events

Fri, Sep 21
10:00 AM - 12:00 PM

Introduction & Objective :

To evaluate the long-term outcomes of patients undergoing observation of asymptomatic renal calculi and identified factors associated with an increased risk of stone related events.


Methods : Patients with asymptomatic renal calculi electing active surveillance of their stones were retrospectively reviewed. Patients underwent annual ultrasound imaging and clinical visits with scandalized questions regarding the development of symptoms or complications from calculi. Spontaneous stone passage, stone growth, symptoms and requirement for intervention during follow-up were deemed as stone related events. Patients characteristics, stones characteristics, and stone related events were collected and analyzed.

Results :

Between 2007 and 2017 a total of 297 patients were reviewed to evaluate the natural history of asymptomatic renal calculi. Mean follow-up was 4.2 years (range 1 to 9). Overall incidences of spontaneous passage, stone growth, symptoms and intervention were 32.1%, 16.7%, 28.3% and 12.3% respectively. Stone size large than 5 mm and lower pole stones were significantly less likely to pass spontaneously during follow-up. Patients with diabetes, hyperuricemia or non-lower calyceal stone were more likely to experience stone growth. Larger stones or non-lower pole stones were more likely to become symptomatic. The significant predictors of surgery intervention were stone size (>5 mm) and patients’ age (>60 years old). Primary therapy was extracorporeal shock wave lithotripsy in 33 patients (91.7%), and flexible ureteroscopy lithotripsy in 3 (8.3%).  


Conclusions : Natural history of asymptomatic renal stones rarely require intervention, although they do have a slightly higher rate of symptomatic events and growth over the intermediate term. Patients with risk factors should be recommended to undergo periodic follow-up and early intervention.

Xiaohang Li

Guangzhou, Guangdong, China (People's Republic)

Guohua Zeng

Vice Director
The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
Guangzhou, Guangdong, China (People's Republic)

Professor Zeng is currently the Vice- President of The First Affiliated Hospital of Guangzhou Medical University, Chief of Guangdong key lab of Urology and Chief of Guangzhou Urology Research Institute. Director of certified fellowship program by Endourology Society. President of Guangdong provincial urological association, Associate member of EULIS.
He completed his Master of Urology training in 1992, and his PhD in Urology in 2000. Clinical endourology fellowship at UT Southwestern Medical Center at Dallas in 2007. As an experienced endourologist, he has finished more than 12000 endourological procedures including all kinds of PCNLs, rigid URS and RIRS procedures and Uro-laparoscopic procedures. Leading the development of RIRS in China, he and his group perform more than 1000 RIRS per year. Prof. Zeng and his colleagues also created a unique mini-PCNL technique, namely Chinese Mini-PCNL, in which more than 30000 Chinese Mini-PCNLs surgeries has been performed by Prof. Zeng and his team with good clinical outcome. He also invented a new minimally invasive technique in treatment of middle size renal stones, called “Super-Mini-PCNL (SMP)”.Main innovation in SMP technique is irrigation and suction in the same sheath, it totally solve all problems in Mini-perc technique including low irrigation flow, difficulty in removal stone fragements, high intrarenal pressure and so on, SMP technique has the advantages of a good irrigation, fast stone fragements evacuation and lower intrarenal pressure, So SMP technique is a conception revolution for mini-perc technique.
Prof. Zeng has gained 5 research projects for stone disease from National Natural Science Foundation. More than 100 academic papers have been published in national and international journals, 10 books about stone disease have been published.

Wenqi Wu

First Affiliated Hospital of Guangzhou Medical University
Guangzhou, Guangdong, China (People's Republic)