ARAB JOURNAL OF UROLOGY 2020, VOL. 18, NO. 3, 176–180 https://doi.org/10.1080/2090598X.2020.1769385 STONES/ENDOUROLOGY: ORIGINAL ARTICLE Antegrade mini-percutaneous ﬂexible ureteroscopy versus retrograde ureteroscopy for treating impacted proximal ureteric stones of 1–2 cm: A prospective randomised study Omar Elgebaly , Hussein Abdeldayem, Faisal Idris, Alaa Elrifai and Ahmed Fahmy Department of Urology, Faculty of Medicine, Alexandria University, Alexandria, Egypt ABSTRACT ARTICLE HISTORY Received 10 January 2020 Objectives: To prospectively assess the safety and eﬀectiveness of antegrade mini- Accepted 28 March 2020 percutaneous (miniperc) ureteroscopy (URS) and compare it with the conventional retrograde URS (RURS) approach in treating impacted proximal ureteric stones of 1–2 cm. KEYWORDS Patients and methods: The study included 60 patients admitted to the Department of Ureteroscopy; laser; mini Urology, Alexandria Main University Hospital, presenting with impacted proximal ureteric percutaneous; impacted; stones of 1–2 cm. Patients were randomly divided into two groups: Group A, were treated proximal ureteric stone with RURS using a semi-rigid or ﬂexible ureteroscope to access the stone; and Group B, were treated by antegrade miniperc URS, were a 14-F renal tract was obtained to pass a ureteric access sheath, then a ﬂexible ureteroscope was used going downwards to the stone. Holmium laser was used for stone fragmentation. A JJ stent was inserted in all cases. Follow-up with non- contrast computed tomography was performed after 2 weeks. Results: Both groups were comparable in terms of patient demographics and stone criteria. The stone-free rate was signiﬁcantly higher in Group B (83.3%) compared to Group A (60%). The mean (SD) operative time was signiﬁcantly shorter in Group A vs Group B, at 64.7 (±17.7) vs 112.0 (±15.3) min; while the mean lithotripsy time was comparable between the groups. The mean radiation exposure time was signiﬁcantly less in Group A (11 s) compared to Group B (200 s). Both groups where comparable concerning minor complications, with no major complications. Conclusion: Antegrade miniperc ﬂexible URS is safe and more eﬀective than RURS for treating large impacted proximal ureteric stones. Abbreviations: ESWL: extracorporeal shockwave lithotripsy; KUB: plain abdominal radiograph of the kidneys, ureters and bladder; miniperc: mini-percutaneous; PCNL: percutaneous nephro- lithotomy; PCS: pelvi-calyceal system; SFR: stone-free rate; (R)URS: (retrograde) ureteroscopy Introduction incidence of 28–60%, hindering the SFR and increasing the need for auxiliary procedures [5,6]. Moreover, stone A large impacted upper ureteric stone describes stones impaction with surrounding mucosal oedema narrows of >1 cm that lie above the lower border of the forth the ﬁeld of vision, and thus increases the risk of compli- lumber vertebra and below the PUJ. There is no estab- cations such as perforation and instrument damage . lished deﬁnition for the term ‘impacted stone’, but it is The antegrade approach is another treatment option for generally accepted that it refers to a stone that causes large impacted upper ureteric stones, which can avoid hydronephrosis, as it remains stationery causing the drawbacks of the retrograde approach. However, it obstruction for >6 weeks. Due to oedema surrounding has its own limitations as regard the invasive nature and the stone, it prevents passage of dye below it during tract formation. We used a mini-percutaneous (miniperc) a contrast study and prevents the passage of a guidewire tract to minimise this limitation. In the present study, we during ureteroscopy (URS) [1–3]. Diﬀerent modalities aimed to prospectively compare the safety and eﬀec- have been reported for managing this category of tiveness of treating large impacted upper ureteric stones stones including: extracorporeal shockwave lithotripsy between the two approaches, i.e., antegrade miniperc (ESWL), retrograde URS (RURS), antegrade approach, URS and conventional RURS. laparoscopy, and rarely open surgery . RURS is now considered the ﬁrst-line procedure for treating upper third ureteric stones, with an overall stone-free rate Patients and methods (SFR) of 81% (range 77–85%) for stones of >1 cm . A common problem with this approach is retrograde The study was performed prospectively and included 60 stone retropulsion during fragmentation, with an patients admitted to the Department of Urology, CONTACT Omar Elgebaly firstname.lastname@example.org Raml Station, Faulty of Medicine, Alexandria University, Alexandria PO 21113, Egypt © 2020 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 177 Alexandria Main University Hospital, from February 2018 migrated fragments in the kidney. A JJ stent (5 F, to May 2019. All the patients presented with solitary large 26 cm, Percuﬂex; Boston Scientiﬁc) was routinely placed impacted proximal ureteric stones of 1–2cm.They were at the end of the procedure. randomly divided into two equal groups (30 patients in each). Group A, treated with RURS and holmium laser Group B, antegrade miniperc URS stone fragmentation; and Group B, treated by antegrade miniperc URS using the same method of stone fragmen- Under general anaesthesia, all patients were placed in tation. Preoperatively, all patients underwent evaluation a prone position. Ultrasonography (US) was used to by history, physical examination, laboratory investigations access the kidney with an 18-G Chiba needle, and then (full blood and urine tests), and radiological investigations dye was injected to opacify the pelvi-calyceal system including plain abdominal radiograph of the kidneys, (PCS). Under ﬂuoroscopic guidance an upper or middle ureters and bladder (KUB) and non-contrast CT to assess calyceal puncture was made. A hydrophilic guidewire stone criteria. Informed medical consent was signed by all was introduced through the needle into the PCS, and patients. We used the closed envelope method for then Teﬂon dilators were used to dilate the tract to randomisation. 14 F. A ureteric access sheath (Navigator 13/11 F; Inclusion criteria: Boston Scientiﬁc) was then inserted through the skin to the PCS over the guidewire. The ﬂexible uretero- Patients with upper third ureteric stones (located scope was introduced through the access sheath to below the PUJ and above the lower border of L4). reach the stone. Stone fragmentation was carried out Adult age group, aged ≥18 years. using the same laser device with same settings as Stones >1 cm in maximum dimension. Group A. A JJ stent (5 F, 26 cm, Percuﬂex; Boston Scientiﬁc) was inserted in an antegrade fashion in all While patients with one or more of the following cri- cases at the end of the procedure. At the end of the teria were excluded from the study: procedure the ureteric access sheath was removed without inserting a percutaneous tube. Untreated UTI. All intraoperative and postoperative data were col- Pregnant females. lected for statistical analysis. These data included Presence of distal obstruction to the stone. operative time, which was deﬁned in Group A as the Presence of associated renal stones. time that elapsed from the start of introducing the Stone size >2 or <1 cm in maximum dimension. instruments through the urethra until JJ-stent inser- tion; while in Group B operative time was deﬁned as the time that elapsed from US-guided puncture until Group A, RURS JJ-stent insertion. Fluoroscopy time and intraoperative Under general anaesthesia, all patients were positioned complications were also reported. in the classic dorsal lithotomy position in a head down Non-contrast CT was done after 2 weeks, before JJ- position. The URS was performed using either a semi- stent removal, for SFR assessment. Stone-free status rigid URS (9.5-F sheath, 8-F tip, 6-F working channel; was deﬁned as the absence of fragments of >0.3 cm Karl Storz SE & Co. KG, Tuttlingen, Germany) or ﬂexible at the time of assessment. Postoperative complications URS (Flex X2, 7.5 F; Karl Storz). The ureteroscope was and the need for auxiliary procedures were reported. inserted over a hydrophilic tipped guidewire (Sensor The primary endpoint in this study was the SFR at polytetraﬂuoroethylene (PTFE)-nitinol guidewire with 2 weeks, while the secondary endpoints included hydrophilic tip; Boston Scientiﬁc, Marlborough, MA, operative time, ﬂuoroscopy time, lithotripsy time, post- USA) through the ureter with or without dilatation of operative complications, and hospital stay. the ureteric oriﬁce if needed using balloon dilatation Data were analysed using the Statistical Package for (Uromax Ultra; Boston Scientiﬁc). In most of our cases the Social Sciences (SPSS®), version 20.0. (SPSS Inc., IBM there was diﬃculty in passing the guidewire beyond Corp., Armonk, NY, USA). The Kolmogorov–Smirnov, the stone at initial attempts due to stone impaction. Shapiro and D’Agstino tests were used to verify the Laser fragmentation was done at the beginning to normality of the distribution of variables. Comparisons create a space for passing a safety guidewire, and between groups for categorical variables were assessed then dusting of the rest of the stone was carried out. using the chi-square test (Fisher’sorMonte Carlo).The Stone fragmentation was performed using a holmium Student’s t-test was used to compare two groups for laser (Auriga XL 50-W holmium Laser, Boston Scientiﬁc) normally distributed quantitative variables and the using 365- or 200-µm ﬁbre, with energy applied at the Mann–Whitney test was used to compare between two settings of: 0.8–1 J/pulse, frequency 6–10 Hz, and long groups for abnormally distributed quantitative variables. pulse duration. Flexible URS was used either from the Signiﬁcance of the obtained results was judged at the 5% start or if stone retropulsion occurred to reach the level. 178 O. ELGEBALY ET AL. Table 1. Patient’s demographics and stone criteria. Group A Group B Variable RURS (n = 30) Antegrade miniperc URS (n = 30) Test of signiﬁcance P Age, years, mean (SD) 45.9 (12.5) 47.5 (11.7) t = 0.490 0.626 Sex, n (%) Male 14 (46.7) 16 (53.3) χ = 0.267 0.606 Female 16 (53.3) 14 (46.7) Stone criteria Size, cm, mean (SD) 1.35 (0.19) 1.33 (0.23) t = 0.487 0.628 Density, HU, mean (SD) 979.4 (234.4) 871.4 (206.7) t = 1.893 0.063 Laterality, n (%) Right 18 (60.0) 22 (73.3) χ = 1.200 0.273 Left 12 (40.0) 8 (26.7) Site L2–L3 6 (20.0) 6 (20.0) χ = 0.444 0.931 L3 8 (26.7) 10 (33.3) L3–4 10 (33.3) 8 (26.7) L4 6 (20.0) 6 (20.0) χ2: chi-square test; t: Student t-test; P: P value for comparison between the studied groups. Table 2. Intraoperative variables and postoperative outcomes. Group A Group B Variable RURS (n = 30) Antegrade miniperc URS (n = 30) Test of signiﬁcance P Operative time, min, mean (SD) 64.7 (17.7) 112.0 (15.3) t = 11.098 <0.001* Lithotripsy time, min, mean (SD) 39 (13.4) 38.3 (10.9) t = 0.211 0.834 Fluoroscopy time, s, mean (range) 11 (8–16) 200 (160–300) U = 0.00* <0.001* SFR, n (%) 18 (60.0) 25 (83.3) χ = 4.022* 0.045* χ2: chi-square test; t: Student t-test; U: Mann–Whitney U-test; P: P value for comparison between the studied groups. *Statistically signiﬁcant at P ≤ 0.05. Results operative time, less radiation exposure and shorter hospital stay; moreover, it is considered the ﬁrst line The study included 60 patients divided equally into the of treatment according to American and European two groups, which were comparable in terms of demo- guidelines on ureteric stone management for stones graphic data and stone criteria, as shown in Table 1. measuring >1 cm . On the other hand, it carries the Intraoperative parameters and postoperative outcomes disadvantage of decreased visualisation due to the are described in Table 2.GroupBhad asigniﬁcantly narrow space around the stone with mucosal oedema higher SFR (83.3%) compared to Group A (60%). leading to an increased incidence of complications, Residual fragments were managed by ESWL in both such as mucosal injury, ureteric wall perforation, instru- groups before JJ-stent removal. Both procedures were ment breakage, and stone retropulsion . Stone retro- successfully carried out and patients were discharged the pulsion is a common problem in RURS during stone next day. All complications recorded were Grade fragmentation, with a reported incidence of 28–60% I according to the Clavien–Dindo Classiﬁcation. Four for upper third ureteric stones. This leads to a decrease patients in Group B (13.3%) had bleeding of <150 mL, in the SFR and increases the need for secondary uro- with no blood transfusion required. Six patients (20%) in logical intervention . Group A had guidewire trauma during laser ﬁring with no The antegrade approach has proven to be a safe total breakage. Postoperative complications were com- and eﬀective treatment option with a higher SFR. It has parable with <50% having mild haematuria and mild the advantage of accessing the stone from the dilated fever. Postoperative pain was reported more in Group B, wide upper ureter, with no risk of stone retropulsion where 16 patients (53.3%) required intravenous analgesia and it provides better visualisation, and thus better and opioids compared to six patients (20%) in Group A. stone fragmentation. On the other hand, some disad- vantages have been noted regarding the renal punc- ture with increased radiation exposure, prolonged Discussion operative time, and postoperative hospital stay . Treatment of large impacted proximal ureteric stones We applied the miniperc technique for our antegrade remains controversial. Both RURS and the antegrade approach to minimise the limitations of this approach. approach represent eﬀective treatment options, with In our present study, 60 patients were included who both having their own pros and cons. RURS has the were randomly divided equally into two groups, Group advantages of less invasiveness as it enter through A (RURS) and Group B (miniperc antegrade URS). All a natural way, easier access to the stone, shorter the patients presented with a solitary large impacted ARAB JOURNAL OF UROLOGY 179 upper third ureteric stone of >1 cm. In the present the study conducted by Li et al. , who reported study, Group A had SFR of 60% signiﬁcantly less than a mean (SD) operative time for percutaneous nephro- Group B (83.3%) after 2 weeks. Factors that improved lithotomy (PCNL) group at 108.76 (±19.36) vs 63.56 the SFR in the antegrade group were the better stone (±16.38) min for the RURS group (P < 0.05). visualisation, pressurised irrigation with no risk of ret- In the present study, no major complications ropulsion, and fragments washout during the proce- occurred while minor complications were reported. dure. Mouﬁd et al.  conducted a retrospective Intraoperative bleeding of <150 mL occurred in four study on 52 patients comparing between RURS using patients in Group B, while there was no bleeding in 9.5/8-F rigid URS and percutaneous antegrade URS Group A. However, none of our patients required using 20.8-F rigid nephroscope in the modiﬁed lateral a blood transfusion. Guidewire injury occurred in six position choosing impacted stones of ≥1.5 cm. The patients in Group A and none in Group B, reﬂecting the study reported a SFR for the retrograde approach of better visualisation during laser lithotripsy from the 66.7%, whereas for the antegrade approach it was wide ureter above the stone were the pressure of the 95.45% through a single tract in one session irrigant ﬂuid can be increased without fear of stone (P = 0.007). Their results were higher than the present retropulsion. Postoperative pain was reported in 16 study concerning the antegrade approach because patients (53.3%) in Group B mostly because of renal they used ballistic lithotripsy and stone extraction, puncture. which was not applicable through the miniperc tract. Many studies have reported an overall low and Another reason may be because they used KUB for similar rate of complications in both groups. Li et al. assessing stone clearance, which has low sensitivity  reported comparable complication rates in both unlike in our present study where we used non- groups, with an increased incidence of ureteric per- contrast CT to assess stone clearance. Similar results foration and stenosis in RURS group, while an conﬁrming the superiority of antegrade approach were increased incidence of haematuria and need for trans- reported by Liu et al. , who had a 97.7% SFR in their fusion in the PCNL group. Sun et al.  reported antegrade group vs 82.2% in their retrograde group. bleeding in one patient (2.3%) for the antegrade pro- In the present study, the operative time was signiﬁ- cedure and ureteric injury in one patient (2.3%) for the cantly shorter in Group A than Group B, at a mean (SD) retrograde procedure, with no statistically signiﬁcance of 64.7 (±17.7) vs 112.0 (±15.3) min. The reason for the diﬀerence. prolonged operative time in Group B was the extra According to our experience during the present time taken for attaining the antegrade renal access study, we believe that the miniperc antegrade including the puncture site, dilatation and reaching approach is a promising alternative to the conven- the stone. In the ﬁrst few cases manipulation of the tional retrograde approach for treating large impacted ﬂexible URS to pass through the PUJ down to the upper third ureteric stones. US-guided renal access in ureter was rather diﬃcult and time consuming, espe- these patients was not diﬃcult due to the presence of cially when we could not pass a wire down the ureter considerable hydronephrosis as a result of stone at the beginning of the renal puncture. In these cases, impaction. Dilatation of the tract to 14 F did not carry we spent time searching for the PUJ opening in the a risk of bleeding in most of the patients. The use of roomy pelvis, while the deﬂecting joint of the ﬂexible ﬂexible URS via the antegrade route was rather diﬃcult URS was inside the ureteric access sheath. However, in in the ﬁrst few cases; however, it became easier with all cases we succeeded to enter through the PUJ and experience and the increasing learning curve. We reach the stone without instrumental trauma. In some believe that approaching the stone from above carries cases the path from the ureteric access sheath down to the advantages of better visualisation, no risk of stone the stone was not straight. In these cases, we were not retropulsion, less risk of mucosal or instrumental injury, able to reach the stone with ﬂexible URS and then pass and better fragments washout. The better visualisation the laser ﬁbre because this was going to risk injuring is due to working from a wider space above the stone the inner channel of the ﬂexible URS. In these cases, we and the ability to push the irrigant ﬂuid without risking had to preload the ﬂexible URS with the laser ﬁbre migration of the stone. The pressurised irrigant helps before passing it through the ureteric access sheath better visualisation and also helps the washout of the to the renal pelvis. While doing this, searching for the fragments via the vacuum cleaner eﬀect. The increased PUJ and manipulating the ﬂexible URS with the laser operative time and radiation exposure account for the ﬁbre inside was more diﬃcult and time consuming. main disadvantages of this approach. A limitation of Diﬀerent published studies have conﬁrmed the the present study is that of being carried out in a single longer operative time in the antegrade approach, centre and also the limited number of patients. The e.g., Mouﬁd et al.  who reported a higher mean primary endpoint in the present study identiﬁed operative time in the Perc URS group compared to the a signiﬁcantly higher SFR with the antegrade RURS group, at a mean (SD) of 66.5 (±21.7) vs. 52.13 approach; we aim to increase the number of patients (±17.3) min (P = 0.013). Similar results were found in and enhance the learning curve to achieve a better 180 O. ELGEBALY ET AL. operative time and avoid the identiﬁed limitations of  Wolf JS Jr. Treatment selection and outcomes: ureteral calculi. Urol Clin North Am. 2007;34:421–430. the study.  Preminger GM, Tiselius HG, Assimos DG, et al. Guideline for the management of ureteral calculi. Eur Urol. 2007;2007(52):1610–1631. Conclusion  Kesler SS, Pierre SA, Brison DI, et al. Use of the escape Antegrade miniperc URS for impacted upper ureteric nitinol stone retrieval basket facilitates fragmentation and extraction of ureteral and renal calculi: a pilot stones is a feasible procedure that improves the SFR study. J Endourol. 2008;22(6):1213–1217. and lessens the need for secondary interventions, but  Elashry OM, Tawﬁk AM. Preventing stone retropulsion at the expense of operative time and radiation during intracorporeal lithotripsy. Nat Rev Urol. 2012;9 exposure. (12):691–698.  Chow GK, Patterson DE, Blute ML. Ureteroscopy: eﬀec- tof technology and technique on clinical practice. Disclosure statement JUrol. 2003;170:99–102.  Türk C, Knoll T, Petrik A, et al. Guidelines on Urolithiasis. The authors declare that they have no conﬂict of interest. European Association of Urology, Arnhem; 2014 [cited 2020 Mar]. Available from: https://uroweb.org/wp- content/uploads/22-Urolithiasis_LR.pdf ORCID  Ding H, Wang Z, Du W, et al. 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Arab Journal of Urology
– Taylor & Francis
Published: Jul 2, 2020
Keywords: Ureteroscopy; laser; mini percutaneous; impacted; proximal ureteric stone