Zhang H et al, 2018: Comparison of the Efficacy of Ultra-Mini PCNL, Flexible Ureteroscopy, and Shock Wave Lithotripsy on the Treatment of 1-2 cm Lower Pole Renal Calculi.
Zhang H, Hong TY, Li G, Jiang N, Hu C, Cui X, Chu C, Zhao JL.
Department of Urology, The First Affiliated Hospital of Soochow University, Suzhou, China.
Department of Urology, Shanghai Pudong New Area Gongli Hospital, Shanghai, China.
Abstract
OBJECTIVE: To compare the efficacy of new percutaneous technique ("ultra-mini PCNL", UMP), shock wave lithotripsy (SWL) and flexible ureteroscopy (FURS) on the treatment of 1-2 cm lower pole kidney stones, and to determine the advantages and disadvantages of each method. MATERIALS AND METHODS: This prospective study was based on data collected from the files of patients between March 2015 and March 2017. This study recruited a total of 180 patients with single radio-opaque lower caliceal calculi of 1-2 cm. All patients were randomly divided into 3 groups: group A was treated with UMP, group B was treated with FURS by using holmium laser and group C was treated with SWL by using the electromagnetic lithotripter. The average age, sex, size of the stone, the time of operation, the rate of no stone, the time of hospitalization, the rate of retreatment, the cost and the complications of the 3 groups were compared. The success of the operation was defined as no residual stone or < 0.3 cm on computed tomography at 3 months postoperatively.
RESULTS: The stone burdens of the groups were equivalent. The re-treatment rate in group C was significantly higher than that in group A and B (30 vs. 1.6%, 5%). The average operating time in group B (93.35 ± 21.64 min) was statistically significantly longer than that in group A and C (68.58 ± 15.82 min, 46.33 ± 5.81 min). Although the time of hospitalization of group A (5.32 ± 1.20 day) was longer than that of group B (3.22 ± 0.52 day) and C (1.08 ± 0.28 day; p < 0.05). The stone-free rate (SFR) in UMP, FURS, SWL were 98, 92, and 73% respectively; the highest SFR was in the UMP group (p < 0.05). The complication rates were evaluated by using the Clavien grading system, which were determined to be 16.67% in UMP, 6.67% in SWL and 8.33% in FURS. In particular, the complications of GI and GII were more common in group A (p < 0.05).
CONCLUSIONS: UMP, FURS, and SWL are all safe and effective in the treatment of 1-2 cm lower pole kidney stones. UMP and FURS had a better SFR than SWL, but the time of hospitalization in UMP group was longer and there were more complications in the UMP group. In addition, the operation time of FURS is longer as compared to UMP and SWL, and there is a higher rate of postoperative fever. The invasiveness and cost of SWL were lower than that of UMP and FURS, but the re-treatment rate was higher.
Urol Int. 2018 Oct 23:1-7. doi: 10.1159/000493508. [Epub ahead of print]
Comments 1
Selection of the most appropriate method for removal of stones from the kidney has remained a controversial matter over the years, ever since the introduction of SWL. Technical improvements of endoscopic instruments and techniques strongly have influenced and modified such decisions during recent years. In this report a randomized comparison was made between small size instrument UMP, FURS and SWL. All treated stones were located in the lower calyx and measured 10-20 mm; that is a category of stones for which guideline recommendations are less clear and straightforward.
The authors correctly state that conclusions on the usefulness of different methods necessarily need to account for a number of variables. Most comparative studies between endoscopic procedures and SWL, in the literature, only have focus on differences in stone free rates.
The data recorded in this report allow calculation of approximate STI values (stone treatment index [1]):
UMP 4.9
FURS 5.1
SWL 8.0
The recorded advantages of SWL (that also explain the higher STI for those patients) were anaesthesia-free treatments, few complications and shorter duration of treatments.
Although it always is difficult and risky to compare economics between different countries, it is of note that the estimated costs for UMP and FURS, respectively, were 7.6 and 8.7 times higher than that for SWL!
The higher re-treatment rates for SWL seem to be compensated for by other specific advantages and it is possible that repeated sessions >2 can result in even better stone clearance. Combination with low-cost inversion/percussion therapy also can improve the results with SWL.
When considering the problem with residuals, it needs to be emphasized that also following complete stone clearance recurrences in about 50% of patients with calcium stone disease should be expected within 5 years.
Factors in defence of SWL relative to endoscopic procedures:
So, what is necessary for the future?
It is desirable to develop or improve methods for non-invasive elimination of fragments from the lower calyces. In that way a completely non-invasive approach can be maintained with SWL, but it needs to be noticed that residuals in the lower calyx often is the end result also with endoscopic procedures irrespective of where the stone initially was located.
Reference:
1. Tiselius HG, Ringdén I.
Stone treatment index: a mathematical summary of the procedure for removal of stones from the urinary tract. J Endourol. 2007 Nov;21(11):1261-9.