|Year : 2017 | Volume
| Issue : 2 | Page : 372-377
Percutaneous nephrolithotomy versus extracorporeal shock wave lithotripsy for moderate-sized kidney stones
Khaled M Aboelkher, Osama A Abd-Elgawad, Tarek M Abd-Elbaky, Eid A Elsherif
Department of Urology, Faculty of Medicine, Menoufia University, Shebin Elkom, Egypt
|Date of Submission||16-Aug-2016|
|Date of Acceptance||02-Oct-2016|
|Date of Web Publication||25-Sep-2017|
Khaled M Aboelkher
Elsabia, Elmahala, 31951
Source of Support: None, Conflict of Interest: None
The aim of this study was to evaluate the effectiveness of extracorporeal shock wave lithotripsy (ESWL) with that of percutaneous nephrolithotomy (PCNL) for managing moderate-sized kidney stones measuring between 100 and 300 mm2 in area.
Shock wave lithotripsy (SWL) is considered a standard treatment for patients with upper-tract stones that are less than 10 mm in diameter, whereas stones that are larger than 20 mm are best managed with PCNL. The management of stones between these sizes remains controversial. Our purpose was to review our contemporary series of SWL, ureteroscopy, and PCNL outcomes for intermediate-sized upper-tract calculi (100–300 mm2).
Patients and methods
This study was conducted at the Urology Department, Menoufia Teaching Hospital, Menoufia University, between December 2013 and February 2015. It study included all patients with moderate-sized renal calculi (range: 1–3 cm) who were planned for management of renal calculi either with PCNL or with ESWL. Patient data were taken as follows: (a) preoperatively, clinical assessment and laboratory investigations; (b) during surgery; and (c) postoperatively, complications and residual stone.
This study included 70 patients with nonstaghorn calculi with an area between 100 and 300 mm. Thirty patients underwent PCNL and 40 underwent ESWL; 49 (70%) patients were male and 21 (30%) were female; 29 (41.4%) patients had right-sided stones and 41 (58.5%) had left sided stones. The mean age of the patients was 34.1 years and the average BMI was 29.0 kg/m2. The mean operative time in our study was 2.36 ± 0.8 h.
This study demonstrates that PCNL and up to two SWL treatments are safe and comparably effective in treating patients with intermediate-sized upper-urinary-tract stones between 100 and 300 mm2 in area.
Keywords: extracorporeal shock wave lithotripsy, percutaneous nephrolithotomy, ureteroscopy
|How to cite this article:|
Aboelkher KM, Abd-Elgawad OA, Abd-Elbaky TM, Elsherif EA. Percutaneous nephrolithotomy versus extracorporeal shock wave lithotripsy for moderate-sized kidney stones. Menoufia Med J 2017;30:372-7
|How to cite this URL:|
Aboelkher KM, Abd-Elgawad OA, Abd-Elbaky TM, Elsherif EA. Percutaneous nephrolithotomy versus extracorporeal shock wave lithotripsy for moderate-sized kidney stones. Menoufia Med J [serial online] 2017 [cited 2019 Jul 22];30:372-7. Available from: http://www.mmj.eg.net/text.asp?2017/30/2/372/215462
| Introduction|| |
A variety of minimally invasive options exist for the treatment of patients with upper-tract urolithiasis, and as technology advances so do the options. Open stone surgery has been rendered obsolete in most situations, being surpassed by antegrade and retrograde endoscopic techniques, as well as extracorporeal shock wave lithotripsy (ESWL). The challenge facing urologists is the need to balance treatment effectiveness against morbidity, based on each clinical scenario. The endoscopic management of urolithiasis has matured over the past decade, with improved instrumentation and techniques for performing both ureteroscopy (URS) and percutaneous nephrolithotomy (PCNL). These two techniques have benefited from the miniaturization of endoscopic instrumentation, the emergence of novel energy devices, such as the holmium laser, improvements in instrumentation flexibility and accessories (i.e., basket devices), and the ongoing dissemination of and increasing familiarity with proper techniques. Several recent reports demonstrate acceptable success rates with retrograde URS for large renal stones ,,.
As with most novel technologies, after their introduction shock wave lithotripsy (SWL) was considered a panacea for the management of the majority of upper-tract stones with high success rates, and its indications for urolithiasis management were broad ,.
Limitations of SWL were soon identified, however. The detailed description by Sampaio and Aragao  of such anatomic parameters as infundibulopelvic angles and length and spatial arrangements of lower calices, followed by the meta-analysis by Lingeman et al.  that demonstrated higher stone clearance rates for PCNL versus ESWL, provided some guidance for urologists in recommending ESWL as a viable treatment option for specific clinical situations. The initial study demonstrated that stone clearance from the lower pole after ESWL worsens as the stone diameter increases beyond 10 mm, whereas PCNL maintains its efficacy as stones increase in diameter . The subsequent study examined lower pole caliceal stones less than 10 mm2 in diameter and found no statistical difference in stone-free rates between SWL and URS, with the caveat that SWL was associated with greater patient acceptance and shorter convalescence .
Randomized controlled trials have given reliable outcomes to aid in treatment decisions for stones smaller than 10 mm2 and larger than 20 mm2. There is a paucity of clinical research, however, that compares the efficacy of the three treatment modalities for stones that measure between 100 and 300 mm2 in area, regardless of the location in the upper urinary tract. The purpose of this study is to review the outcomes of a recent series of patients who were referred for treatment of renal calculi with a stone area between 100 and 300 mm2.
| Aim|| |
The aim of the current study was to evaluate the effectiveness of ESWL compared with PCNL for managing moderate-sized kidney stones measuring between 100 and 300 mm2 in area.
| Patients and Methods|| |
This study was conducted at the Urology Department, Menoufia Teaching Hospital, Menoufia University, between December 2013 and February 2015. The study included all patients with moderate-sized renal calculi (range: 1–3 cm) who were planned for management of renal calculi either with PCNL or with ESWL. Patient data ware taken as follows: (a) preoperatively – clinical assessment through detailed medical history (personal history, analysis of complaint, past medical and surgical history), physical examination (general and urological), and laboratory investigations; (b) during the surgery; and (c) postoperatively – complications and residual stone.
The merits of the study were explained to the patients. Patients had the right to withdraw from the study at any time without jeopardizing their medical care. Informed consent was obtained from them. The data collected were kept confidential and were used for research purposes only. Any unexpected risks that appeared during the course of the research were informed to the patients and the ethical committee on time.
The data were coded and entered using SPSS (version 15; SPSS Inc., Chicago, Illinois, USA). The data were summarized using descriptive statistics: mean, SD, minimal and maximum values for quantitative variables, and number and percentage for qualitative values. Statistical differences between groups were tested using the c2-test for qualitative variables, the independent sample t-test for quantitative normally distributed variables, and the nonparametric Mann–Whitney test for quantitative variables that were not normally distributed. P values less than or equal to 0.05 were considered statistically significant.
| Results|| |
This study included 70 patients with nonstaghorn calculi with an area between 100 and 300 mm. Thirty patients underwent PCNL and 40 underwent ESWL; 49 (70%) patients were male and 21 (30%) were female; 29 (41.4%) patients had right-sided stones and 41 (58.5%) had left-sided stones. The mean age of the patients was 34.1 years and the average BMI was 29.0 kg/m 2. The mean operative time in our study was 2.36 ± 0.8 h.
Complications and outcome
In this study complications were classified into intraoperative and early postoperative complications and comprised fever, hematuria, and postoperative infections.
The PCNL group saw intraoperative bleeding in five (16.6%) patients: three patients were managed with a nephrostomy tube (Neleton 24 Fr), which was fixed as a tamponade; the other patients were treated conservatively. The difference between preoperative and postoperative hemoglobin level was used as an indicator of blood loss; the mean decrease in hemoglobin level was 0.96 g/dl. There was perforation of the pelvicalyceal system and extravasation in three (10%) patients: perforation occurred during dilatation of the tract and fragmentation of stones. A DJ ureteric stent was fixed in these three patients, which was removed after 6 weeks. Postoperative fever occurred in 17 patients; their mean temperature was 38 ± 0.7°C for 1 day, which was controlled by standard perioperative antibiotics (e.g., third-generation cephalosporin). Regarding the stone-free status, there was complete stone clearance in 28 (93.3%) patients. This was confirmed with routine plain urinary tract radiography, which was performed on the first postoperative day. In two (6.6%) patients there were residual stones that were treated by URS [Table 1].
|Table 1: Complications (intraoperative and early postoperative) and outcomes|
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In the ESWL group postoperative fever occurred in four patients, who had a mean temperature of 38 ± 0.6°C and were managed with standard antibiotics (e.g., third-generation cephalosporin). With regard to late postoperative complications, steinstrasse occurred in four patients, which was treated by URS. Complete stone clearance was recorded in 24 (60%) patients. This was confirmed with routine plain urinary tract radiography, which was performed after 1 week. In 16 (40%) patients there were residual stones that were treated by a second session of ESWL [Table 2].
Single treatment success
Single-treatment success rate was significantly better for PCNL at 93.3%, versus 60% for SWL (P < 0.01), whereas with two sessions of SWL treatments the success rate improved to 77.5% and with three SWL treatments the success rate improved further to 85.0%. More than two sessions of ESWL show comparable results to those of PCNL (P = 0.66). Sixteen (40%) patients underwent repeated SWL for their original stone, and of those patients three (7.5% of all SWL patients) underwent three treatments [Table 3].
Auxiliary treatments, defined as repeat of the initial treatment modality or progression to other modalities, were more common after SWL (42.5 vs. 6.6% in the PCNL). Four (10%) patients who underwent initial SWL needed subsequent URS for definitive stone management [Table 3]. Success rates across modalities are presented in [Table 3].
With regard to hospital stay, all patients undergoing PCNL were admitted overnight for observation (P < 0.01). When measuring the mean length of hospital stay postoperatively, there was a significant difference between the SWL therapy group (0.17 days) and the PCNL group (2.9 days) (P < 0.01) [Table 4].
All PCNL patients underwent ureteral stent placement preoperatively, whereas 35% of patients in the SWL group underwent periprocedural ureteral stent placement (P = 0.04) [Table 4].
| Discussion|| |
Selecting the optimal treatment for intermediate-sized stones (those between 100 and 300 mm2) can be challenging for patients and urologists alike, because each treatment modality has unique advantages and disadvantages. ESWL is minimally invasive and needs only neuroleptic anesthesia, making it the preferred initial treatment choice by many patients and physicians for a wide range of urolithiasis ,. Despite the widespread SWL usage, stone-free rates are poor for stones that are located in the lower calyx, especially if the stones are more than 10 mm2 in diameter . PCNL for larger stones has replaced ESWL as the primary treatment modality despite being associated with higher morbidity ,. The literature showed series-acceptable success rates with SWL for staghorn or larger renal calculi ,. However, this is not widely performed, nor is it considered the standard of care in the urologic community . In our study, all procedures were carried out in the prone position; percutaneous renal access was obtained by the urologist under fluoroscopic guidance. A lower calyx approach was used in 24 (80%) patients and involved the fewest complications. Middle access was used in five (16.6%) patients and lower access in one (3.3%) patient. The choice of access was dependent on the site of the stones.
A study was conducted in the UK by Armitage et al.  on 1028 patients that reported that most procedures were undertaken in the prone position and only 6% were performed with patients supine. Renal access was obtained by a radiologist in 62% of patients and by an urologist in 38%. Access was mostly guided by fluoroscopy alone in 68% or in combination with ultrasound guidance in 29%; in 3% of patients ultrasound imaging was the only mode of guidance, and computed tomography was used in 0.1% of patients. A study by El-Assmy et al.  suggested that the urologist is able to obtain renal access safely and that the outcomes are at least equivalent to those of the radiologist. Our findings support this.
Proper access is a prerequisite for complete clearance of renal calculi by PCNL. The ideal tract is one that provides the shortest and straightest access to all calculi . In our study, the mean age of all patients was 34.1 years and the average BMI was 29.0 kg/m 2. This is comparable to those in other studies.
The mean operative time in our study was 2.36 ± 0.8 h, which is similar to the time reported by Kurtulus et al.  (2.2 h). Gupta et al.  reported a mean operative time of 80.2 min. Falahatkar et al.  also reported a mean operative time of 67.42 ± 26.25 min. The longer operative time in our study can be explained by the fact that our procedures were performed in a teaching hospital and by surgeons with different levels of experience.
In the current study treatment success was defined as a stone-free status or clinically insignificant residual fragments (residual fragment <4 mm). Carlsson et al. analyzed the stone-free status (free of stones or fragments ≤5 mm) and revealed success rates of 76% (19/25) for ESWL and 100% (15/15) for PCNL, and 77% (20/26) for ESWL and 94% (18/19) for PCNL, at the end of the fourth week and at 1 year, respectively. Albala et al.  reported the overall stone-free status (stone fragments ≤3 mm in diameter) based on the initial stone size at the end of the third month and revealed success rates of 37% for ESWL and 95% for PCNL, with significant difference between the two modalities. Wankhade et al.  reported the overall stone-free status as 67.94% (53/78 patients) for ESWL and 97.43% (76/78 patients) for PCNL.
In the current study, when comparing single-treatment rates across groups, the stone-free and success rates were significantly lower in those patients who were treated with ESWL than in those patients who were treated with PCNL (60% for ESWL and 93.3% for PCNL), with significant difference between the two modalities. This is in accordance with the results ofWankhade et al. , Albala et al. , and Carlsson et al. .
Rao et al. reported a significant difference between ESWL and PCNL in the overall need for retreatment and auxiliary procedures: with respect to retreatment, 17.1% (44/257 patients) for ESWL and 0% (0/77 patients) for PCNL; with respect to auxiliary procedures, 13.6% (35/257 patients) for ESWL and 1.3% (1/77 patients) for PCNL. Further, Deem et al.  reported a significant difference between ESWL and PCNL in the same parameters: with respect to retreatment, 35% (3/12 patients) for ESWL and 0% (0/20 patients) for PCNL; with respect to auxiliary procedures, 41.7% (5/12 patients) for ESWL and 5% (1/20 patients) for PCNL.
In the current study, auxiliary treatment rates are significantly higher for patients in the ESWL arm, but this is largely because retreatment rates are higher (42.5% (17/40) for ESWL versus 6.6% (2/30) for PCNL (P = 0.01). This is in accordance with the reports ofRao et al.  and Deem et al. .
Treatment of residual stone was dependent on the site and size of residual fragments: either URS in two (6.6%) patients in the PCNL group or second session of ESWL in 16 (40%) patients, and URS in four (10%) patients due to steinstrasse in the ESWL group. In our study, pelvicalyceal system perforation occurred in three (10%) patients, whereas in the study by Michel et al.  perforation of the collecting system occurred in 7.2% of cases and was caused by the use of a straight guidewire. DJ ureteric stent was fixed for these patients, which was removed after 6 weeks.
The complications in the study by Carlsson et al.  were hematuria and fever (over 38°C). Pain was not considered a complication. They measured complications at days 1, 3, 5, 7, and 9. The period of hematuria in the ESWL group was longer than that in the PCNL group. Hematuria was still present at day 9 in the ESWL group but not in the PCNL group. Fever was reported less in the ESWL group than in the PCNL group. In our study, hematuria was observed in all patients in the ESWL group, compared with 12 (40%) patients in the PCNL group. Postoperative fever was seen in four patients in the ESWL group and in 17 (56.6%) patients in the PCNL group. The temperature was more than 38.5°C, which improved with simple antipyretics and antibiotics. In a study by Troxel and Low  conducted on 128 patients in Mahidol University Siriraj Hospital, Thailand, 42.4% of patients had temperature more than 38.5°C, which is comparable to our study's (56.6%), although all patients received preoperative and postoperative prophylactic antibiotics. The source of infection always comes from the stone itself, as explained by Viville .
Yuruk et al.  reported lower pole scarring (five patients) with ESWL, and postoperative fever (one patient), bleeding necessitating blood transfusion (one patient), and lower pole scarring (one patient) with PCNL. In our study, intraoperative bleeding occurred in five (16.6%) patients, which was a minor bleed from the access tract that necessitated neither a blood transfusion nor embolization. Three of these patients were managed with a nephrostomy tube (Neleton 24 Fr), which was fixed as a tamponade. Other patients were treated conservatively. The difference between preoperative and postoperative hemoglobin level was used as an indicator of blood loss; the mean decrease in hemoglobin level was 0.96 g/dl, which was higher than that reported by Shaban et al. , who reported 0.79 g/dl mean hemoglobin drop. In the current study, there were no significant differences between patients who were treated with SWL and those with PCNL.
All minor complications in the SWL arm were in patients who returned to either the clinic or emergency department with renal colic secondary to steinstrasse (n = 4), postoperative fever (n = 4), and postoperative infection (n = 3). In the PCNL group, there were complications that consisted of a minor bleed from the access tract (n = 5) that necessitated neither a blood transfusion nor embolization, and minor complications that consisted of postoperative fever (n = 17) and postoperative infections (n = 8). Wiesenthal et al.  reported a significantly shorter hospital stay for ESWL. Albala et al.  reported a mean hospital stay of 0.55 days for ESWL and 2.66 days for PCNL. In the current study, when measuring the mean length of hospital stay postoperatively, there was a significant difference between ESWL (0.17 days) and PCNL (2.9 days) (P < 0.01). Repeated treatments to match the efficacies in ESWL arm make it approximately equal.
Urologists who favor SWL treatment for these sizes and locations of stones might base their decision on the minimally invasive nature of the day procedure and negligible anesthetic requirements with the caveat of potentially multiple treatments and the need for a ureteral stent with stones greater than 15 mm in diameter. Finally, urologists favoring PCNL do so based on the excellent single-treatment success rates with the moderately invasive procedure, possible anesthetic difficulties in the prone position, need for nephrostomy tubes or stents, and a short postoperative hospitalization.
| Conclusion|| |
This study demonstrates that PCNL and up to two SWL treatments are safe and comparably effective in treating patients with intermediate-sized upper-urinary-tract stones with an area between 100 and 300 mm2. Although SWL necessitates repeated treatments for optimal efficacy, it is less invasive and obviates the need for a general or spinal anesthetic, postoperative hospitalization, and periprocedural insertion of ureteral stents or nephrostomy tubes in a significant percentage of patients.
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Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4]