Research Article: Minimally invasive percutaneous nephrolithotomy improves stone-free rates for impacted proximal ureteral stones: A systematic review and meta-analysis

Date Published: February 2, 2017

Publisher: Public Library of Science

Author(s): Zi-Ming Gao, Shan Gao, Hong-Chen Qu, Kai Li, Ning Li, Chun-Lai Liu, Xing-Wang Zhu, Yi-Li Liu, Ping Wang, Xiao-Hua Zheng, Shian-Ying Sung.


Urinary stones are common medical disorders and the treatment of impacted proximal ureteral stones (IPUS) is still a challenge for urologists. The aim of this study was to compare the efficacy and safety of minimally invasive percutaneous nephrolithotomy (MI-PCNL) and ureteroscopic lithotripsy (URL) in the treatment of IPUS via a meta-analysis.

We collected studies using PubMed, Embase, and Cochrane Library from 1978 to November 2016 and analyzed them using Stata 12.0 and RevMan 5.3. Odds ratios (ORs) and standard mean difference (SMD) were calculated for binary and continuous variables respectively, accompanied with 95% confidence intervals (CIs). All study procedures followed the PRISMA guidelines.

Five prospective studies were included in our meta-analysis, with 242 MI-PCNL and 256 URL cases. MI-PCNL was associated with a longer postoperative hospital stay than URL (SMD, 3.14; 95% CI, 1.27 to 5.55). However, no significant difference was observed in operative time (SMD, -0.38; 95% CI, -3.15 to 2.38). In addition, MI-PCNL had higher initial (OR, 11.12; 95% CI, 5.56 to 22.24) and overall stone-free rates (OR, 8.70; 95% CI, 3.23 to 23.45) than URL, along with lower possibilities of surgical conversion (OR, 0.11; 95% CI, 0.03 to 0.49) and postoperative shock wave lithotripsy (OR, 0.06; 95% CI, 0.02 to 0.18). Regarding complications, no significant differences were observed between MI-PCNL and URL (OR, 1.39; 95% CI, 0.93 to 2.10), except for hematuria (OR, 4.80; 95% CI, 1.45 to 15.94).

MI-PCNL is optimal and should be considered as the preferred treatment method for IPUS, as it has better efficacy and a safety profile similar to that of URL. However, further high quality studies with larger sample size are required in future.

Partial Text

Urinary stones are frequently occurring medical disorders worldwide and their incidence has been increasing in recent years.[1] Most of them are upper urinary stones (UUS), including ureteral and renal stones. In the last decade, extracorporeal shock wave lithotripsy (ESWL), ureteroscopic lithotripsy (URL) and percutaneous nephrolithotomy (PCNL) have emerged as common surgical treatment options for UUS, while open surgery is only needed in a few rare circumstances.[2] With advancements in technology, new methods such as, flexible URL, minimally invasive PCNL (MI-PCNL) and laparoscopic ureterolithotomy, have provided more treatment choices to urologists. Within these, MI-PCNL (12-20F) has the advantages of reduced hemorrhage, postoperative pain and hospital stays than traditional PCNL, and has been recommended by many urologists.[3, 4]

All procedures followed the PRISMA guidelines (S1 Table); the search and selection process is presented in Fig 1. A total of four RCTs and one non-randomized concurrent controlled trial (Non-R) studies were included in our meta-analysis, with 242 MI-PCNL and 256 URL cases.[5, 10–13] In the URL group, 183 patients underwent surgery with a rigid ureteroscope (R-URL), while the other 73 patients received treatment with the flexible ureteroscope (F-URL). The original characteristics and data from the selected publications are listed in Table 1, and the quality evaluation is presented in the supporting information. Forest plots of the meta-analysis on efficacy and safety are presented in Figs 2–4. In addition, our analysis had no significant publication bias.

Recently, the incidence of urinary stones has increased significantly due to changes in people’s diets and lifestyle. Among different urinary stones, IPUS is a special type which indicates long-term retention of stones at the proximal ureter. Urination is always difficult for IPUS patients and if not treated in time, renal failure and other life-threatening diseases might occur. Ureteral polyp is the major cause of IPUS and it always needs to be treated at the same time. Recently, PCNL and URL have emerged as the two common methods used for treatment of IPUS. However, there are advantages and disadvantages of both procedures, and which procedure is optimal for IPUS remains unclear and challenging for urologists.

MI-PCNL has better efficacy and similar safety compared to URL. Thus, MI-PCNL is the optimal method among these two for treatment of IPUS. However, studies with larger sample size and detailed records are needed to further validate our results.




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