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The effect of stone size on the results of extracorporeal shockwave lithotripsy versus semi-rigid ureteroscopic lithotripsy in the management of upper ureteric stones The effect of stone size on the results of extracorporeal shockwave lithotripsy versus semi-rigid...
El-Abd, Ahmed S.; Tawfeek, Ahmed M.; El-Abd, Shawky A.; Gameel, Tarik A.; El-Tatawy, Hasan H.; El-Sabaa, Magdy A.; Soliman, Mohamed G.
2022-01-02 00:00:00
ARAB JOURNAL OF UROLOGY 2022, VOL. 20, NO. 1, 30–35 https://doi.org/10.1080/2090598X.2021.1996820 STONES/ENDOUROLOGY: ORIGINAL ARTICLE The effect of stone size on the results of extracorporeal shockwave lithotripsy versus semi-rigid ureteroscopic lithotripsy in the management of upper ureteric stones Ahmed S. El-Abd, Ahmed M. Tawfeek, Shawky A. El-Abd, Tarik A. Gameel, Hasan H. El-Tatawy, Magdy A. El- Sabaa and Mohamed G. Soliman Urology Department, Faculty of Medicine, Tanta University, Tanta, Egypt ABSTRACT ARTICLE HISTORY Received 12 February 2021 Objectives: To evaluate the role of stone size on the efficacy and safety of extracorporeal Accepted 27 May 2021 shockwave lithotripsy (ESWL) monotherapy vs ureteroscopy (URS) for managing upper ureteric stones. KEYWORDS Patients and methods: The study design was a randomised prospective study of a total cohort Stones; extracorporeal of 180 patients with upper ureteric single stones of 0.5–1.5 cm. Half of the patients were shockwave lithotripsy; managed by ESWL monotherapy, while the other half underwent URS with stone fragmenta- ureteroscopy tion using an ultrasound lithotripter (URSL). The success rate, re-treatment rate, auxiliary procedure (AP) rate, efficacy quotient, and complications were compared between the two groups. Results: After single URSL and ESWL procedures 70/90 (77.8%) and 35/90 (38.9%) of the stones were successfully cleared, respectively (P < 0.001). The re-treatment rate after ESWL was significantly higher than in the URSL group (38.9% vs 11.1%, P < 0.001). Requiring an AP was not significantly different following ESWL (22.2%) and URSL (24.4%) treatment. The overall stone-free rate (SFR) at 3 months was significantly superior in the URSL group (88.9% vs 77.8%); however, both procedures had excellent results with no significant difference for stones of <1 cm (95.5% vs 92.9%, P > 0.05), compared to better results following URSL for stones of >1 cm (82.6% vs 64.6%, P < 0.05). Conclusion: Our present study supports that ESWL is recommended as a first-line non-invasive monotherapy for upper ureteric opaque stones of <1 cm, while URSL is recommended as a first- line treatment for stones of >1 cm. The results for URSL were superior with lower a re-treatment rate, rapid stone clearance in a very short time, and less radiation exposure. Therefore, stone size is an important factor for the final decision of the initial management of upper ureteric stones because it has a direct relation to the efficacy of ESWL, but it has no effect on the results of URSL. Introduction The aim of the present randomised study was to compare ESWL vs ureteroscopic lithotripsy (URSL) Upper ureteric stones are usually associated with obstructive using ultrasonic disintegration in the treatment of uropathy with gradual and progressive impairment in renal uncomplicated upper ureteric stones of 0.5–1.5 cm function. Patients presenting with upper ureteric stones with the effect of stone size on the results. receive debated treatment modalities, starting from extracor- poreal shockwave lithotripsy (ESWL) to contact lithotripsy via an antegrade or retrograde approach [1]. ESWL is an out- Patients and methods patient non-invasive treatment that does not require anaes- From December 2015 to June 2020, patients with single, thesia, but it may not render the patient stone-free in one proximal radio-opaque ureteric stones of up to 1000 session [2]. Hounsfield units (HU) between the PUJ and the sacro- With the use of a small calibre long ureteroscope, recent iliac joint with a stone size of 0.5–1.5 cm in the longest auxiliary instruments, and disintegration tools; treatment of diameter were included in the study. Patients with active upper ureteric stones can be effectively achieved with urinary infection, morbid obesity, multiple or impacted improved stone-free rates (SFRs) and minimal complications stones of >1.5 cm, prior JJ stents, uncorrected coagulo- [3]. The incidence of stone migration was reported to be as pathy, impaired renal function, pregnancy, and cases high as 48% after using pneumatic lithotripsy with subse- presenting with anuria or bilateral stones were all quent mandatory additional procedures, which increase mor- excluded. bidity and cost burden [4]. CONTACT Mohamed G. Soliman mohagab2006@yahoo.com Urology Department, Faculty of Medicine, Tanta University, Tanta, Egypt © 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ARAB JOURNAL OF UROLOGY 31 After obtaining approval of the local Ethics Other evaluated parameters included immediate Committee, the nature of the trial was explained to SFRs (ISFRs), operative and fluoroscopy time. Results the patients and informed consent was obtained from were compared according to the size of stones in each the willing participants. The patients were then ran- group. Complications reported in both groups were domly assigned to two treatment groups: Group 1, compared based on the Clavien–Dindo classification. ESWL and Group 2, URSL. Patients underwent either The EQ for both groups was calculated using the of the procedures as a primary treatment without any following formula: biased selection by using a random numbers table, ðpercentage of SFR � 100Þ with 90 patients treated in each group. EQ ¼ ð100 þ percentage of retreatmentþ percentage of APÞ All patients were assessed preoperatively with full blood count, renal and liver function, coagulation pro- Sample size calculation: the sample size was pro- file and urine analysis, culture, and sensitivity. spectively evaluated using the goodness-of-fit test for Radiological evaluation included plain abdominal contingency tables with ‘effect size w’ of 0.5, α error radiograph of the kidneys, ureters, and bladder (KUB), protection of 0.05 and power of 0.80. Based on these and spiral non-contrast CT (NCCT). data a total sample size of 61 patients was needed to The ESWL was performed using a Dornier Compact be included in each of the study groups. Delta II (Dornier MedTech, Munich, Germany). Patients were treated in a supine position under intravenous analgesia using nalbuphine 20-mg infusion as an out- Statistical analysis patient procedure. The maximum number of shocks per session was 4000, at rate of 80–100/min, or until Data were statistically analysed using the IBM complete disintegration of the stone was observed by Statistical Package for the Social Sciences (SPSS®) ver- fluoroscopy. The shockwave energy was gradually sion 25 (IBM Corp., Armonk, NY, USA). The chi-square increased, according to patient tolerance as analgesia test and unpaired t-test were used to assess differences was administered routinely to have a stable patient dur- among groups for categorical variables and continu- ing the session. The number of sessions needed for stone ous variables, respectively. The differences were con- fragmentation and number of shocks used in every ses- sidered statistically significant for P< 0.05. sion were recorded. The URSL was done under spinal or general anaesthesia using 8.5-F semi-rigid ureteroscope Results (Richard Wolf, Knittlingen, Germany), and disintegra- A total of 180 out of 200 patients with proximal ure- tion was done under direct vision. Dilatation of ure- teric stones completed the study protocol, 90 patients teric orifice when needed was done using a balloon in each group. The rest of these patients did not com- catheter or double lumen ureteric dilator. plete the follow-up after first treatment (Figure 1). In Intracorporeal lithotripsy was done using an ultra- both groups, no statistically significant difference was sound lithotripter, using a stone cone as an ante- observed in patient data recorded in (Table 1). retropulsion tool. All fragments were extracted using In the ESWL group, the ISFR was 38.9% with 35/90 URS forceps and the cone was released inside the patients cleared from stone after only one session. The urinary bladder. After completion of the procedure overall SFR included a total of 70 patients (77.8%) who guided by both direct vision and fluoroscopic con- became stone free after three sessions, while another trol, a 6-F ureteric catheter was placed for 2 days. If eight patients (8.9%) had clinically insignificant residual extensive manipulation or mucosal injury had fragments (CIRF) of <0.4 cm. These patients were asymp- occurred, or incomplete disintegration and in cases tomatic at the 3-month follow-up without any increase in with solitary renal unit, a 6-F JJ was placed for size. Two-thirds of the failed cases (nine of 12) and all 4 weeks. cases with CIRF (eight) were seen in patients with stones Success was defined as clearance of all fragments of >1 cm. guided by KUB and NCCT 4 weeks after the procedure. There was no impact of age, sex, and side of the The indication for re-treatment was planned when the stone on the results, but complete clearance with no original treatment was insufficient to render the CIRF was significantly higher in 39/42 cases with a stone patient stone free (when the residual stone was size of <1 cm (92.9%), compared to larger stones of >0.4 cm) whether using ESWL or URSL. >1 cm in 31/48 patients (64.6%, P< 0.01; Table 2) An auxiliary procedure (AP) was considered when a different procedure was implemented to clear all the The mean number of ESWL sessions per patient for residual stones or to treat any complication. smaller stones (<1 cm) was 1.5 compared to 1.9 for The primary outcome of the study was to evaluate the cases with stones of >1 cm (P< 0.05). Also significantly overall SFR. Secondary outcomes included re-treatment more shocks per session were needed for larger stones rate, APs, and estimated efficacy quotient (EQ). (P< 0.01). 32 A. S. EL-ABD ET AL. Exclusion criteria: Stones < 0.5 cm or > 1.5 cm Figure 1. Patients flow through the study. Table 1. Patients’ characteristics in both groups. Regarding re-treatment and APs for the manage- Characteristic ESWL URSL P ment of failed primary procedures, in the ESWL Number of patients 90 90 group re-treatment was needed in 38.9% (35/90), Age, years, mean (SD) 42 (12) 44.7 (10) 0.106 Sex, male/female, n 51/39 49/41 0.764 while APs were used in 22.2% (20/90) including Side, right/left, n 41/49 42/48 0.764 eight patients managed with JJ insertion. The Proximal dilatation, n 60 56 0.881 Stone size, mm, mean (SD) 11.1 (2.09) 11.3 (2.13) 0.529 remaining 12 patients (13.3%) who failed ESWL treat- Stone density, HU, mean (SD) 796.27 (101.48) 819.02 (116.12) 0.082 ment were cleared from stones after URSL in 10 cases and open uretero-lithotomy in two (refused re- treatment with URSL). All patients submitted to URSL were discharged the In the URSL group, the re-treatment rate, and the next morning, with the mean (range) operative time of need for an AP was reported in 10/90 patients (11.5%) 50 (25–115) min and dilatation of ureteric orifice was and 22/90 patients (24.4%), respectively. All patients performed in 25/87 cases (28.7%) using a double- submitted to a second session of URSL became stone lumen ureteric catheter (n= 15) or balloon catheter free (in four patients with stones <1 cm and in six with (n= 10). The procedure was converted to open surgery stones >1 cm; Table 2). in four cases due to large extravasation in two patients, An AP was needed in 22 patients (six patients man- and a hard stone and distal ureteric kink each in one aged with ESWL, 12 with JJ insertion and four were patient. Only one of these patients had a small stone converted to open uretero-lithotomy). The re- of <1 cm. treatment rate was significantly higher in the ESWL In this group, the ISFR was reported to be 77.8%. For group compared with the URSL group (P< 0.001); how- stones of <1 cm, the ISFR was 86.4% (38/44 patients) vs ever, there was no significant difference in the 69.6% (32/46 patients) for stones of >1 cm. The overall APs (P= 0.4) SFR was 88.9% (80/90) and it was 95.5% (42/44) for In the ESWL group, the estimated EQ was 0.8 and stones of <1 cm vs 82.6% (38/46) for stones of >1 cm 0.46 for stones of < and >1 cm, respectively. While in (Table 2). the URSL group, the EQ was 0.79 and 0.57 for stones of Comparing the results in the two groups for the < and >1 cm, respectively. overall SFR as the primary outcome, there was no significant difference for stones of <1 cm (P= 0.5). The mean (SD) fluoroscopy time after ESWL was 56 Conversely, for stones of >1 cm, URSL showed (3.4) s, compared to significantly less radiation expo- a significantly better success rate in comparison to sure during URSL, with a mean (SD) fluoroscopy time of the ESWL group (P= 0.04). 18 (6.6) s (P< 0.001, Table 3). ARAB JOURNAL OF UROLOGY 33 Table 2. Data and results after URSLs and ESWL in relation to stone size. ISFR, 1 month Overall SFR, 3 months Re-treatment, n AP, n EQ ESWL, n/N (%) <1 cm (n = 42) 23 (54.8) 39 (92.9) 16 ESWL 0.80 >1 cm (n = 48) 12 (25) 31 (64.6) 19 ESWL 10 URSL + 2 open + 8 JJ 0.46 Total (n = 90) 35/90 (38.9) 70/90 (77.8) 35 ESWL 10 URSL + 2 open + 8 JJ 0.48 URSL, n/N (%) <1 cm (n = 44) 38 (86.4) 42 (95.5) 4 URSL 1 ESWL + 1 open +4 JJ 0.79 >1 cm (n = 46) 32 (69.6) 38 (82.6) 6 URSL 5 ESWL + 3 open + 8 JJ. 0.57 Total (n = 90) 70/90 (77.8) 80/90 (88.9) 10 URSL 6 ESWL + 4 open + 12 JJ 0.59 Statistics ESWL vs URSL Chi-square P Chi-square P <1 cm (n = 86) 8.931 0.001 0.003 0.479 > 1 cm (n = 94) 16.96 <0.001 3.041 0.041 Total (n = 180) 26.423 <0.001 3.24 0.036 All complications in our series were considered as morbidity. The treatment options vary from direct minor (Clavien–Dindo Grade I–II) in both the ESWL and contact lithotripsy to in situ non-contact ESWL for URSL groups. medium size stones, up to laparoscopic or open In the ESWL group, 16 patients (17.8%) developed uretero-lithotomy for complicated cases with large complications with more than one complication in stones [5]. In recent years, new generations of ESWL some patients. Clinical haematuria after 24 h was machines are associated with minimal tissue encountered in 12 cases but variable degrees of renal damage, less anaesthesia, and higher re-treatment colic, dysuria and vomiting were seen in 27 (30%), 10 rate [6]. However, as a non-invasive treatment it can (11%) and four patients (4.5%), respectively; all mana- be done as an outpatient procedure with high ged conservatively including α-blockers in two cases patient tolerance even on re-treatment, and no (2.2%) with steinstrasse. Hospital admission was neces- need for theatres or prior stenting and stent sary in four patients due to severe renal colic. removal. This is reflected on the overall costs and Complications in the URSL group included dysuria time for stone clearance [7]. ESWL has a high suc- and renal colic, all were managed conservatively, but cess rate of 85–96% for small proximal ureteric one patient needed hospitalisation for intravenous stones after prior JJ stenting, but this success rate fluids and analgesics. is lower for larger stones [8]. We performed a prospective randomised study of ESWL vs URSL of 0.5–1.5 cm stones in the upper ureter using Discussion ultrasonic disintegration without prior stenting. In our present study, the ISFR of ESWL for stones < Various treatment modalities have been reported and >1 cm was 54.8% and 25%, respectively, although for management of upper ureteric stones. The deci- the overall stone clearance rate at 3 months was 92.9% sion of which treatment to implement depends on and 64.6%, respectively. The total stone clearance rate many factors, e.g. stone size, degree of the proximal was 77.8% with significant better results in smaller backpressure, presence of distal obstruction, the stones at this site. We excluded patients with prior available technology, and surgical experience. All ureteric surgery or morbid obesity and advanced of these are important for selecting the most suita- hydronephrosis not only because of the negative ble technique for the best SFR and minimal impact on stone disintegration and subsequent stone clearance rate, but also to include in the study only patients that could be treated with either ESWL or Table 3. Statistical analysis of the results. URSL. These situations have previously been asso- ESWL URSL (N = 90) (N = 90) Statistic P ciated with higher re-treatment rates and prolonged Overall success rate, n/ 70/90 80/90 Chi-square 0.033 clearance [9]. N (%) (77.8) (88.9) = 3.24 The ESWL was performed without anaesthesia <1 cm, n/N (%) 39/42 42/44 Chi-square 0.479 (92.9) (95.5) = 0.003 and the patient left the ESWL unit immediately >1 cm, n/N (%) 31/48 38/46 Chi-square 0.041 after disintegration, but the re-treatment rate was (64.6) (82.6) = 3.041 Re-treatment, n/N (%) 35/90 10/90 Chi-square <0.001 significantly greater compared to URSL (P < 0.001). (38.9) (11.1) = 17.07 The need for an AP was not significantly different AP, n/N (%) 20/90 22/90 Chi-square 0.430 (22.2) (24.4) = 0.031 between the ESWL (22.2%) and URSL (24.4%) EQ 0.48 0.59 groups; however, those with larger stones in the Open, n/N (%) 2/90 4/90 Chi-square 0.339 (2.2) (4.4) = 0.172 ESWL group required re-treatment with more ESWL Fluoroscopy time, s, 56 (3.4) 18 (6.6) t = 48.385 <0.001 sessions (1.9 vs 1.5) and more shocks per session. mean (SD) This was observed in our present study and many Re-hospitalisation, 4 (4.5) 1 (1.1) Chi-square 0.385 n (%) = 1.75 other previous reports [9–11]. Therefore, we found 34 A. S. EL-ABD ET AL. that the stone size is an important predictor for the Limitations of the present our study include the SFR after ESWL, with reduced efficiency in large absence of the use of flexible URSL with laser disinte- stones. In the situation of large upper ureteric gration and the lack of a paediatric age group; how- stones, the stone is also surrounded by small disin- ever, these parameters are currently under evaluation tegration chamber compared to similar size stones for comparison. in the pelvicalyceal system, which is reflected by the Complications with renal colic and dysuria that better stone disintegration and clearance [12]. need re-hospitalisation were significantly higher in In recent years, the refinement of ureteroscopes the ESWL group with large stones (4:1). All other com- (diameter and vision) and internal disintegration plications were managed conservatively without major tools, including laser, have made treatment of stones morbidity. The need for open intervention was not in the upper ureter a viable competitor to ESWL. The significantly different between the groups (2.2% and debate depends on the non-invasiveness of ESWL and 4.4%). On the other hand, the mean fluoroscopy time the availability of semi-rigid ureteroscopes in most and radiation exposure was significantly shorter in the urology centres, which are more durable, less expen- URSL group than in the ESWL group (P< 0.001). sive, can be done as an outpatient procedure with higher success rates and superior stone clearance in Conclusion a shorter time [13]. Also many patients prefer to be free from the stone in one session with no need for re- Our present study supports that ESWL is recom- treatment or APs [14]. Although the highest success mended as a first-line non-invasive monotherapy for after URSL was seen for lower ureteric stones, the new upper ureteric opaque stones of <1 cm, while URSL is tools with the semi-rigid and flexible ureteroscopes recommended as a first-line treatment for stones of has been associated with high success rates for upper >1 cm. The results for URSL were superior with a lower ureteric stones [15]. re-treatment rate, rapid stone clearance in a very short Size by size, the overall SFR after URSL (95.5%) and time, and less radiation exposure. Therefore, stone size ESWL (92.9%) was excellent in small stones, but URSL is an important factor for the final decision of the initial was significantly superior for larger stones of >1 cm, at management of upper ureteric stones because it has 82.6% vs 64.6%, (P < 0.05). The re-treatment rate after a direct relation to efficacy of ESWL, but it has no effect URSL was 11.5%, which was significantly lower than the on results of URSL. 38.9% in the ESWL group; however, the need for an AP was not significantly different between the groups, Abbreviations especially in patients with large stones. The estimated EQ in small stones was 0.79 and 0.8 for URSL and ESWL AP: auxiliary procedure; CIRF: clinically insignificant with no significant difference; however, URSL displayed residual fragments; EQ: efficacy quotient; ESWL: extra- a better efficacy (0.57) than ESWL (0.46) in large size corporeal shockwave lithotripsy; HU: Hounsfield units; stones due to a higher re-treatment rate that lowered KUB, plain abdominal radiograph of the kidneys, the EQ of patients treated with ESWL. Therefore the ureters, and bladder; NCCT, non-contrast CT; (I)SFR: stone size did not affect the efficacy of URSL, although (immediate) stone-free rate; URS(L): ureteroscopy a better EQ of ESWL was seen with small stones (0.8) (lithotripsy) than the large stones (0.46). The results of our present study are consistent with many other previous studies Disclosure statement [16,17]. Other advantages of URSL are that it can be done as an outpatient procedure under minimal anaes- No potential conflict of interest was reported by the thesia with a high success rate and minimal need for re- author(s). treatment and secondary procedures, which coincides with the desire of most patients in our present series ORCID and other previous reports [18]. Also many studies supported URSL as a safe procedure with stenting Mohamed G. Soliman http://orcid.org/0000-0001-8465- unnecessary and absence of intraoperative complica- tions [19,20]. Furthermore, it can be used for failed cases after ESWL, radiolucent stones and in pregnancy References [21]. However, the smaller semi-rigid ureteroscopes with [1] Tzelves L, Turk C, Skolarikos A. 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