1392 | Department of Urology, Dr D. Mišović Clinical Center, Belgrade, Serbia. Slaviša Savić, Vinka Vukotić, Miodrag Lazić, Nataša Savić Management of Calculus Anuria Us- ing Ureteroscopic Lithotripsy as a First Line Treatment: Its Efficacy and Safety Corresponding Author: Slaviša Savić, MD Department of Urology, Dr. D. Misovic Hospital, H.M. Tepica 1, 11000 Belgrade, Serbia. Tel: +381 11 3630600 Fax: +381 11 3672025 E-mail: drsavics@yahoo. com Received May 2013 Accepted December 2013 Purpose:‎To‎present‎our‎experience‎with‎emergency‎ureteroscopic‎lithotripsy‎(URSL)‎for‎ureteral‎ calculi‎associated‎with‎acute‎kidney‎injury‎(AKI).‎ Materials and Methods:‎We‎retrospectively‎evaluated‎the‎61‎patients‎consisted‎of‎90‎ureteral‎units‎ (UU),‎who‎underwent‎URSL.‎The‎cause‎of‎anuria‎was‎bilateral‎calculus‎obstructions‎in‎29‎cases,‎ and‎unilateral‎calculus‎obstruction‎with,‎absent,‎nephrectomized‎contralateral‎kidney‎in‎32‎cases.‎ In‎the‎case‎of‎bilateral‎synchronous‎ureteric‎calculi‎same-session‎bilateral‎ureteroscopy‎(SBBU)‎ was‎done.‎The‎duration‎of‎anuria‎varied‎between‎12‎to‎72‎hours.‎At‎the‎end‎of‎the‎procedure,‎ure- teral‎stent‎was‎systematically‎left‎in‎place‎in‎all‎patients.‎Surgery‎was‎performed‎6-12‎hours‎after‎ admission‎to‎hospital.‎Patients‎were‎followed‎at‎least‎1‎month‎postoperatively. Results:‎The‎stone‎free‎rates‎(SFR)‎were‎determined‎as‎baseline,‎on‎the‎first‎post-operative‎day,‎ and‎as‎overall‎on‎the‎30‎days‎after‎procedure.‎The‎greatest‎success‎was‎achieved‎in‎the‎distal‎ localization‎of‎stones‎up‎to‎10‎mm‎(93%).‎Renal‎function‎returned‎in‎51‎(83.6%)‎patients‎within‎ 7‎days.‎In‎18‎(29.5%)‎patients‎[18‎(20%)‎UU]‎we‎performed‎second‎procedure‎as‎extracorporeal‎ shockwave‎lithotripsy‎in‎16.7%‎and‎open‎surgery‎in‎2.2%.‎In‎43‎(70.5%)‎patients‎URSL‎was‎a‎suc- cessful‎therapeutic‎approach‎in‎dealing‎with‎pain,‎obstruction‎and‎calculus. Conclusion: Calculus‎anuria‎is‎a‎medical‎emergency‎that‎requires‎rapid‎diagnosis‎and‎prompt‎ treatment‎for‎the‎purpose‎of‎decompression.‎URSL‎is‎the‎proper‎method‎of‎choice‎for‎selected‎ patients‎and‎can‎be‎performed‎safely‎and‎has‎high‎success‎rates‎with‎minimal‎morbidity. Keywords: ureteral‎calculi,‎surgery;‎ureteroscopy;‎lithotripsy;‎kidney,‎abnormalities;‎anuria,‎ther- apy;‎treatment‎outcome. Endourology and Stone Disease ENDOUROLOGY AND STONE DISEASE 1393Vol. 11 | No. 02 | March- April 2014 |U R O LO G Y J O U R N A L INTRODUCTION Acute‎kidney‎injury‎(AKI)‎has‎been‎defined‎in‎mul-tiple‎studies‎using‎varying‎changes‎in‎serum‎cre-atinine,‎urine‎output,‎need‎for‎renal‎replacement‎ therapy‎and‎estimated‎glomerular‎filtration‎rate.(1)‎Acute re- versible‎kidney‎injury‎(ARKI)‎secondary‎to‎bilateral‎ureteral‎ obstruction‎(BUO)‎is‎a‎common‎urological‎problem‎and‎the‎ underlying‎etiology‎can‎be‎malignant‎or‎benign.(2) Post‎renal‎anuria‎is‎a‎urologic‎emergency‎that‎must‎be‎man- aged‎rapidly‎and‎carefully;‎otherwise‎the‎glomerular‎filtra- tion‎rate‎(GFR)‎will‎decline‎rapidly,‎with‎rise‎of‎blood‎urea‎ and‎serum‎creatinine‎and‎water-electrolytes‎imbalance.‎Then‎ a‎series‎of‎symptoms‎in‎other‎organs‎will‎be‎evident‎and‎ lastly‎multiple‎organs‎failure‎will‎result‎and‎the‎patient’s‎life‎ will be threatened.(3)‎The‎patient‎who‎presents‎with‎acute‎uri- nary‎obstruction‎is‎in‎need‎of‎urgent‎drainage‎of‎the‎urinary‎ tract‎either‎by‎ureteral‎stenting‎or‎percutaneous‎nephrostomy‎ (PCN).‎Timely‎ decompression‎ may‎ result‎ in‎ complete‎ re- covery‎of‎renal‎function.(4)‎Post‎renal‎anuria‎is‎mostly‎due‎to‎ obstruction‎of‎the‎urinary‎tract‎and‎the‎most‎common‎cause‎ of‎urinary‎obstruction‎is‎ureteral‎calculi.(5)‎Calculus‎anuria‎ is‎a‎urological‎emergency‎and‎anuria‎can‎be‎due‎to‎bilateral‎ ureteric‎calculus‎impaction‎or‎to‎unilateral‎ureteric‎calculus‎ impaction‎of‎a‎solitary‎kidney‎or‎to‎only‎a‎single‎function- ing‎kidney.‎Acute‎unilateral‎ureteral‎obstruction‎due‎to‎stones‎ is‎a‎frequent‎event,‎affecting‎5%‎to‎15%‎of‎the‎population‎ worldwide.(6) Ureteroscopic‎ lithotripsy‎ (URSL)‎ represents‎ the‎ golden‎ standard‎for‎the‎treatment‎of‎ureteric‎stones‎in‎the‎case‎of‎ bilateral synchronous ureteral calculi, and the options are a staged‎or‎a‎synchronous‎URSL‎procedure.‎Bilateral‎same- session‎ureteroscopy‎(SSBU)‎can‎reduce‎in‎overall‎operative‎ time‎and‎hospital‎stay,‎prevent‎multiple‎surgical‎procedures‎ and‎anesthesia,‎minimize‎the‎duration‎of‎convalescence‎and‎ also‎ complications,‎ provided‎ that‎ the‎ surgeon‎ has‎ enough‎ experience‎in‎endoscopic‎procedures.‎Conversely,‎the‎tech- nique‎would‎expose‎both‎ureters‎ to‎ injury‎that‎could‎lead‎ to‎significant‎morbidity.‎Gunlusoy‎and‎colleagues‎reported‎ that‎bilateral‎single-session‎pneumatic‎lithotripsy‎can‎be‎per- formed‎safely‎and‎has‎high‎success‎rates‎with‎minimal‎mor- bidity and short hospital stay.(7) Patients‎with‎a‎solitary‎kidney‎need‎to‎become‎stone-free‎as‎ soon‎as‎possible‎due‎to‎risk‎of‎acute‎obstructive‎renal‎insuffi- ciency.‎Since‎URSL‎offers‎both‎immediate‎relief‎from‎symp- toms‎and‎stone‎fragmentation‎with‎minimal‎complications,‎ it‎may‎be‎successfully‎used‎for‎the‎management‎of‎ureteral‎ calculi‎in‎patients‎with‎a‎solitary‎kidney. We‎report‎our‎experience‎with‎urgent‎URSL‎and‎with‎SSBU- URSL‎as‎a‎first‎line‎treatment‎in‎condition‎of‎acute‎anuria‎ caused‎by‎obstructive‎calculi.‎The‎primary‎endpoint‎of‎the‎ study‎was‎to‎determine‎the‎outcomes‎of‎treatment‎for‎patients‎ with‎obstructive‎anuria. MATERIAL AND METHODS Patients and Study Design This‎retrospective‎chart‎analysis‎was‎conducted‎at‎the‎De- partment‎of‎Urology,‎Dr.‎D.‎Mišović‎Hospital,‎Belgrade,‎Ser- bia.‎From‎among‎nearly‎1234‎patients‎who‎had‎undergone‎ URSL‎in‎our‎clinic,‎between‎January‎1998‎and‎January‎2013,‎ 61 patients presented clinically as acute calculus anuria and treated‎urgently‎with‎URSL‎or‎SSBU.‎A‎total‎of‎3‎surgeons‎ performed‎these‎procedures.‎ The‎cause‎of‎anuria‎was‎bilateral‎obstruction‎by‎the‎calculi‎in‎ 29‎cases,‎and‎unilateral‎obstruction‎with‎/absent/‎nephrecto- mized‎contralateral‎kidney‎in‎32‎cases.‎In‎unilateral‎cases‎ne- phrectomy‎had‎been‎already‎done‎due‎to‎tumor‎in‎8‎patients,‎ calculosis‎in‎19‎patients‎and‎non-functioning‎diseased‎kidney‎ in‎5‎patients.‎ Retrospectively,‎the‎patients‎are‎grouped‎on‎the‎basis‎of‎the‎ duration‎of‎anuria.‎Group‎A‎included‎patients‎with‎anuria‎ lasting‎up‎to‎48‎hours‎and‎group‎B‎included‎patients‎with‎ anuria‎of‎over‎48‎hours‎in‎duration.‎These‎two‎groups‎are‎ compared‎ with‎ regard‎ to‎ post-operative‎ recovery‎ of‎ renal‎ function,‎at‎the‎7th‎post-operative‎day.‎We‎defined‎recovery‎ of‎renal‎function‎on‎the‎basis‎of‎amount‎of‎post-obstructive‎ diuresis‎and‎levels‎of‎serum‎creatinine.‎Thus,‎we‎compare‎ the‎relation‎between‎the‎duration‎of‎anuria‎and‎early‎post- operative‎recovery‎of‎renal‎function‎after‎successful‎relief‎of‎ obstruction‎via‎emergency‎URSL‎using‎Fisher’s‎exact‎test.‎ Generally‎patients‎were‎selected‎for‎SSBU‎based‎on‎surgeon‎ judgment‎that‎each‎side‎could‎be‎treated‎safely‎and‎effective- ly.‎URSL‎was‎initially‎started‎on‎the‎side‎in‎which‎stone‎size‎ was‎smaller‎and‎lower‎localization‎than‎the‎other. Clinical Procedure All‎interventions‎were‎carried‎out‎under‎regional‎or‎general‎ anesthesia,‎ with‎ a‎ semi-rigid‎ single‎ channel‎ Olympus‎ 9.8‎ Management of Calculus Anuria Using TUL | Savic et al 1394 | channel‎(Ch)‎ureteroscope.‎An‎EKL‎(electrokinetic)‎and‎elec- trohydraulic‎(EHL)‎generator,‎Lithotron‎Walz‎EL-27‎Com- pact‎(Walz,‎Germany)‎was‎used. Patients‎were‎admitted‎on‎an‎emergency‎basis.‎On‎admis- sion,‎detailed‎history‎of‎pain,‎urinary‎output,‎fever,‎hematuria‎ and‎uremic‎symptoms‎with‎durations‎were‎recorded.‎Urine‎ output‎between‎0-100‎mL/24‎hours‎was‎regarded‎as‎anuria.‎ General‎physical‎examination‎and‎systemic‎examination‎with‎ especial‎reference‎to‎the‎genitourinary‎tract‎was‎performed‎ and‎positive‎findings‎were‎recorded.‎Investigations‎included‎ complete‎hematologic‎examination,‎blood‎urea,‎serum‎cre- atinine,‎serum‎electrolytes‎including‎plasma‎potassium‎level.‎ Ultrasonography‎(US)‎and‎plain‎film‎of‎the‎abdomen‎were‎ performed‎in‎all‎cases‎to‎evaluate‎the‎size,‎site‎and‎number‎ of‎stones,‎degree‎of‎hydronephrosis‎(UHN),‎echogenicity,‎re- nal‎cortical‎thickness,‎and‎presence‎of‎either‎kidneys‎or‎soli- tary‎kidney.‎Before‎surgery‎(45‎min),‎the‎patients‎received‎ a‎single‎dose‎of‎antibiotics‎intravenously‎(cephalosporin‎or‎ fluoroquinolone),‎which‎was‎then‎continued‎during‎the‎hos- pitalization. URS‎access‎was‎successfully‎achieved‎in‎all‎cases‎without‎ the‎need‎for‎ureteral‎orifice‎dilatation.‎Endoscopic‎inspection‎ was‎done‎at‎the‎end‎of‎the‎procedure‎to‎rule‎out‎any‎residual‎ calculi‎>‎2‎mm‎or‎ureteral‎lesion.‎Operation‎time‎was‎calcu- lated‎from‎the‎time‎the‎ureteroscope‎was‎introduced‎into‎the‎ urethra‎to‎the‎time‎of‎final‎removal‎of‎the‎endoscope.‎Proxi- mal‎and‎distal‎ureteral‎stones‎were‎defined‎as‎those‎above‎ and‎below‎the‎pelvic‎brim,‎respectively,‎as‎suggested‎by‎Hol- lenback‎and‎colleagues.(8)‎Pigtail‎ureteral‎6‎Fr‎polyurethane‎ stent‎or‎ureteral‎probe‎6‎Ch‎we‎routinely‎placed‎in‎all‎pa- tients.‎Ureteral‎probes‎have‎been‎removed‎at‎postoperative‎ days‎1-4‎(mean‎2.5). The‎decision‎on‎displacement‎of‎the‎ureteral‎stent‎was‎based‎ on‎clinical‎and‎intraoperative‎characteristics‎including‎dura- tion‎of‎anuria,‎the‎size‎and‎number‎of‎calculi,‎the‎degree‎of‎ calculus‎impaction‎and‎mucosal‎edema,‎stone‎free‎status‎on‎ the‎first‎post-operative‎days,‎the‎volume‎of‎urine‎output,‎lab- oratory‎analysis.‎Double‎J‎(DJ)‎ureteral‎stents‎were‎removed‎ after‎2-4‎weeks‎under‎local‎anesthesia.‎Post-operatively,‎all‎ patients‎were‎evaluated‎by‎monitoring‎urine‎output,‎serum‎ creatinine‎blood‎urea‎and‎plasma‎potassium‎daily,‎until‎nor- mal‎or‎acceptable‎levels‎were‎obtained.‎We‎used‎≥‎33%‎de- crease‎in‎serum‎creatinine‎after‎intervention‎as‎confirmation‎ of‎AKRI.(9)‎Plain‎film‎of‎the‎abdomen‎and‎ultrasonography‎ were‎performed‎at‎the‎first‎day‎post-operatively‎(to‎assess‎ the‎initial‎stone-free‎rate‎and‎to‎confirm‎the‎correct‎stent‎po- sition)‎and‎during‎the‎follow-up‎visits‎(after‎2‎weeks‎and‎4‎ weeks).‎Close‎collaboration‎between‎urological,‎nephrologi- cal‎and‎radiological‎services‎was‎been‎required,‎and‎care‎was‎ taken‎to‎avoid‎hypovolemia‎that‎could‎potentially‎cause‎fur- ther injury. Follow-up Procedure For‎the‎success‎criteria‎(intraoperative‎success‎was‎defined‎ endoscopically),‎we‎determined‎stone‎diameters‎≤‎2‎mm‎as‎ stone-free‎rate‎(SFR).‎Fragments‎less‎than‎2‎mm‎were‎left,‎ since‎they‎can‎pass,‎but‎larger‎fragments‎were‎extracted‎by‎ Endourology and Stone Disease Table 1. Clinical and stone characteristics of study population. Variables Anuria < 100 mL/24-hour, no. (%) Duration, no. (%) 9 (14.8) 48-hour 38 (62.3) 72-hour 14 (23) Hydronephrosis, no. (%) Grade 1 23 (25.6) Grade 2 48 (53.3) Grade 3 19 (21.1) Level of serum creatinine (µmol/L) 492 (range, 200-800) Level of blood urea (mmol/L) 27 (range,11-39) Plasma potassium level (mmol/L) 6 (range 5.7- 6.9) Stone size (mm) Overall 9 (5-16) < 10 mm 56 (62.2%) >10 mm 34 (37.8%) Stone number, no. (%) Solitary 84 (93) Multiple 6 (7) Stone opacity (%) Radiopaque 82 Radiolucent 18 Localization, no. (%) Proximal ureter 27 (30) Distal ureter 63 (70) Time to operation (hour) 6-12 Mean operative time (min) 34 (range, 19-65) Mean hospitalization stay (day) 5.4 (2-12) Basket / grasper / forceps use (per ureteral unit) 59 (65.5%) 1395Vol. 11 | No. 02 | March- April 2014 |U R O LO G Y J O U R N A L Management of Calculus Anuria Using TUL | Savic et al Table 2. Stone-free rates as function of stone location. Stone Free Rate Ureteral Units Stone Localization Stone Size ----- ----- Proximal n = 27 Distal n = 63 < 10 mm n = 56 > 10 mm n = 34 Postoperative 56 (62) 9 (33) 46 (73) 39 (70) 16 (47) Overall, 30 days after operation 73 (81) 15 (56) 59 (94) 52 (93) 21 (62) *are presented as number (%). Dormia‎sound‎or‎stone‎grasper.‎ Postoperative‎success‎(overall‎stone-free‎status)‎was‎deter- mined‎as‎no‎significant‎stone‎fragments‎greater‎than‎2‎mm‎in‎ diameter‎on‎initial‎follow-up‎radiography‎and‎plain‎abdomi- nal‎X-ray‎performed‎at‎least‎1‎month‎after‎surgery,‎due‎to‎the‎ limited‎ availability‎ of‎ non-contrast‎ abdomino-pelvic‎ com- puted‎tomography‎(CT)‎scan‎as‎gold‎standard‎in‎our‎country.‎ Intraoperative‎ and‎ postoperative‎ complications‎ associated‎ with procedure were recorded and reported according to the Clavien-Dindo‎classification‎of‎surgical‎complications.(10) This‎study‎protocol‎was‎approved‎by‎the‎Ethical‎Committee‎ of‎the‎Hospital‎Dragiša‎Mišović‎and‎the‎research‎was‎carried‎ out‎in‎compliance‎with‎the‎Helsinki‎Declaration.‎All‎patients‎ gave‎written‎informed‎consent‎before‎participation‎and‎then‎ underwent ureteroscopy. RESULTS In‎the‎27‎(44%)‎men‎and‎34‎(56%)‎women‎with‎a‎mean‎age‎ of‎52‎years‎old‎(range‎34‎to‎81)‎a‎total‎of‎88‎urgent‎URSL‎ were‎done.‎Percutaneous‎nephrostomy‎was‎performed‎in‎2‎ (3.3%)‎patients,‎2‎(2.2%)‎ureteral‎units‎(UU)‎with‎bilateral‎ calculus,‎with‎severely‎ impacted‎hard‎distal‎stones.‎These‎ patients‎were‎candidates‎for‎open‎surgery,‎ureterolithotomy,‎ 6‎to‎8‎weeks‎after‎the‎primary‎intervention‎(URSL+PCN).‎ The‎duration‎of‎anuria‎varied‎between‎1‎to‎3‎days.‎We‎did‎ not‎observe‎any‎cases‎of‎pyuria‎during‎the‎procedure.‎Stone‎ burden‎was‎determined‎by‎measuring‎the‎maximum‎stone‎di- mension.‎In‎cases‎of‎multiple‎stones,‎these‎dimensions‎were‎ added‎together.‎The‎clinical‎and‎stone‎characteristic‎of‎our‎ study‎population‎are‎shown‎in‎Table‎1.‎Stone-free‎rates‎are‎ stratified‎by‎stone‎location‎in‎Table‎2. Stone‎migration‎to‎the‎kidney‎(push-back)‎occurred‎in‎12‎UU‎ (12‎patients),‎in‎7‎UU‎(7‎patients)‎with‎unilateral,‎and‎in‎5‎UU‎ (5‎patients)‎with‎bilateral‎obstruction‎during‎upper‎ureteric‎ stone‎manipulation,‎and‎DJ‎stents‎were‎left‎in‎these‎ureters.‎ Migrated‎stones‎were‎subjected‎to‎extracorporeal‎shockwave‎ lithotripsy‎(SWL)‎5-11‎days‎after‎URSL,‎after‎normalization‎ of‎serum‎creatinine.‎ At‎the‎end‎of‎the‎procedure‎ureteral‎stent‎was‎placed‎bilater- ally‎in‎44‎UU‎(22‎patients)‎and‎unilaterally‎in‎32‎UU‎(25‎ patients‎with‎solitary‎kidney‎and‎in‎7‎patients‎with‎BUO,‎ ureteral‎stent‎placed‎unilaterally).‎Nine‎patients,‎returned‎to‎ the‎emergency‎room‎because‎of‎pain‎24‎hours‎after‎removing‎ the ureteral stent. Ultrasound showed UHN, and a DJ stent was‎placed‎in‎order‎to‎secure‎urinary‎drainage.‎Six‎of‎these‎ patients‎had‎a‎solitary‎kidney,‎and‎were‎complemented‎by‎ medical‎expulsive‎therapy‎(MET)‎treatment‎while‎in‎three‎ patient, three ureteral units, the planned secondary procedure was‎SWL.‎ Post-operative‎monitoring‎of‎patients‎is‎shown‎in‎Table‎3.‎ Post-operative‎ monitoring‎ of‎ urine‎ volume‎ revealed‎ post- obstructive‎diuresis‎or‎polyuria‎in‎recovery‎phase,‎in‎all‎pa- tients, but the urine output gradually decreased to reach nor- mal‎level‎within‎the‎1st‎week‎postoperatively.‎Also,‎serum‎ creatinine,‎blood‎urea‎and‎plasma‎potassium‎levels‎returned‎ to‎normal‎or‎acceptable‎levels‎within‎7-10‎days.‎ In‎Table‎4,‎the‎patients‎are‎grouped‎according‎to‎the‎duration‎ of‎anuria‎(up‎to‎48-hour‎and‎over‎48-hour).‎Recovery‎of‎renal‎ function‎as‎indicated‎by‎post-obstructive‎diuresis‎and‎serum‎ creatinine‎is‎compared‎in‎these‎two‎groups‎of‎patients‎using‎ Fisher’s‎exact‎test.‎It‎is‎seen‎that‎the‎recovery‎of‎renal‎func- tion‎was‎poorer‎in‎the‎patients‎with‎longer‎duration‎of‎anuria.‎ Recovery‎of‎renal‎function‎at‎discharge‎was‎confirmed‎in‎51‎ (83.6%)‎patients.‎ In‎44‎(72%)‎patients‎URSL‎is‎a‎successful‎therapeutic‎ap- proach‎ for‎ relief‎ of‎ obstruction‎ and‎ removal‎ of‎ calculus.‎ 1396 | Endourology and Stone Disease Treatment‎modalities‎in‎relation‎to‎UU‎are‎shown‎in‎Table‎ 5.‎A‎secondary‎procedure‎was‎required‎in‎17‎(18.9%)‎UU.‎A‎ classification‎(modified‎Clavien‎system)‎has‎been‎proposed‎ to‎grade‎perioperative‎complications‎(Table‎6).‎Major‎com- plications‎(such‎as‎sepsis,‎perforation,‎and‎avulsion)‎were‎not‎ observed‎during‎the‎procedure. URSL‎provoked‎significant‎mucosal‎ laceration‎with‎guide‎ wire‎at‎the‎site‎of‎impacted‎ureteral‎stone‎in‎5‎(8.2%)‎patients.‎ To‎treat‎this‎complication‎ureteral‎stent‎placement‎was‎suf- ficient.‎Stone‎or‎fragment‎migration‎was‎seen‎at‎12‎(19.7%)‎ patients, all in the upper stone localization, and that was the major‎cause‎of‎failure‎of‎the‎procedure.‎ Mild‎ macroscopic‎ hematuria‎ was‎ observed‎ in‎ the‎ first‎ 24‎ hours‎which‎did‎not‎require‎treatment.‎There‎was‎postopera- tive‎high‎grade‎fever‎in‎8‎(13.1%)‎patients.‎The‎body‎tem- perature‎ returned‎ to‎ normal‎ within‎ 4‎ days‎ after‎ receiving‎ maximum‎ dose‎ and‎ intravenously‎ injected‎ 3rd‎ generation‎ cephalosporin‎antibiotic‎(urine‎from‎ureteral‎stent‎for‎urine‎ culture‎-‎with‎positive‎urine‎culture‎results,‎Escherichia‎coli). Postoperative‎ “pain”‎ (renal‎ colic),‎ was‎ the‎ most‎ frequent‎ complication,‎ mandating‎ a‎ readmission‎ in‎ two‎ patients‎ (3.3%)‎with‎solitary‎kidney,‎emergency‎department‎visit‎in‎9‎ (14.8%)‎patients‎(of‎whom‎4‎patients‎had‎bilateral‎stent),‎or‎ re-instrumentation‎second‎URSL‎in‎1‎(1.6%)‎patient‎treated‎ for‎large‎bilateral‎calculi‎>‎15‎mm‎in‎one‎session.‎ Minor‎complications‎such‎as‎lower‎urinary‎tract‎symptoms‎ (LUTS),‎ mild‎ hematuria,‎ flank‎ and‎ pelvic‎ pain‎ improved‎ within‎one‎week‎after‎stent‎removal. DISCUSSION The‎standard‎first-line‎approach‎in‎the‎management‎of‎symp- tomatic‎ureteral‎stone‎is‎relief‎of‎obstruction‎by‎insertion‎of‎a‎ nephrostomy‎tube‎or‎a‎DJ‎ureteral‎stent‎and‎fragmentation‎of‎ the‎stone‎subsequently.‎Insertion‎of‎a‎nephrostomy‎tube‎under‎ local‎anesthesia‎is‎relatively‎less‎invasive‎and‎is‎considered‎to‎ be‎better‎if‎there‎is‎evidence‎of‎sepsis‎at‎the‎time‎of‎presen- tation.‎Nevertheless,‎its‎potential‎disadvantages‎are‎leakage,‎ dislodgement‎of‎the‎tube‎and‎the‎need‎to‎manage‎the‎stoma.(11) Ureteroscopy‎ is‎ a‎ relatively‎ complication-free‎ procedure.‎ However,‎if‎complications‎do‎occur,‎they‎may‎be‎related‎to‎ the‎procedure‎itself.‎The‎main‎advantages‎of‎URSL‎are‎im- mediate‎relief‎of‎symptoms‎and‎stone‎fragmentation.‎Quick‎ ureteral‎ stone‎ removal‎ may‎ be‎ important‎ in‎ patients‎ with‎ calculus‎anuria.‎Ureteroscopy‎has‎variable‎complications‎(9- 20%)‎including‎bleeding,‎ureteral‎perforation,‎false‎passage,‎ urinoma‎formation,‎strictures‎and,‎ in‎a‎few‎cases,‎ureteral‎ avulsion.(12)‎Lee‎and‎Bagly‎reported‎that‎ureteroscopy‎should‎ be‎safe‎with‎regard‎to‎renal‎function,‎there‎is‎no‎puncture,‎ as‎in‎percutaneous‎nephrolithotomy‎(PCNL),‎and‎no‎shock- waves‎directed‎to‎renal‎parenchyma,‎as‎in‎SWL.‎However,‎ Table 3. Postoperative monitoring of study population. Monitoring POD 1 POD 3 POD 7 POD 10 Ultrasonography + + Distal n = 63 < 10 mm n = 56 Plain abdominal film + 46 (73) 39 (70) Postobstructive diuresis + ----- 59 (94) 52 (93) Range, 2400-8300 mL/24-hour Laboratory analysis Mean complete blood count + + + ----- Serum creatinine + + + + Blood urea + ----- + + Plasma potassium + + + Urine from ureteral stent for UC + ----- ----- Keys: POD, postoperative day; UC, urine culture. * Optional. 1397Vol. 11 | No. 02 | March- April 2014 |U R O LO G Y J O U R N A L Management of Calculus Anuria Using TUL | Savic et al other‎potential‎mechanisms‎of‎injury‎during‎URSL‎such‎as‎ excessive‎irrigation‎may‎generate‎sufficient‎pressure‎in‎the‎ kidney‎to‎cause‎pyelovenous‎backflow‎and‎damage‎the‎re- nal‎parenchyma.‎Thermal‎injury‎may‎also‎occur‎due‎to‎the‎ energy‎of‎ the‎ laser.‎However,‎ this‎ is‎unlikely,‎as‎ frequent‎ irrigation should dissipate the heat energy, so ureteroscopic laser‎lithotripsy‎has‎no‎harmful‎impact‎on‎renal‎function‎in‎ patients‎with‎mild‎to‎moderate‎renal‎insufficiency.(13) Some‎authors‎stated‎that‎in‎comparison‎with‎unilateral‎ureter- oscopy,‎no‎difference‎was‎found‎with‎bilateral‎same‎session‎ ureteroscopy‎with‎regard‎to‎complication‎rate‎(6.7%)‎or‎stone- free‎rate‎(80%)‎and‎concluded‎that‎bilateral‎same-session‎ure- teroscopy‎is‎a‎safe‎and‎effective‎procedure‎in‎the‎management‎ of‎bilateral‎ureteral‎stones.‎Bilateral‎same-session‎ureterosco- py‎can‎prevent‎frequent‎surgeries‎and‎anesthesia‎and‎reduce‎ hospital‎stay.‎Proper‎patient‎selection,‎ample‎experience‎of‎the‎ surgeon,‎and‎appropriate‎instruments,‎all‎reduce‎complications‎ and‎increase‎treatment‎success.(14)‎Initial‎opposition‎to‎SSBU‎ arose‎from‎concerns‎that‎each‎renal‎unit‎could‎be‎compro- mised‎simultaneously.‎While‎it‎is‎rare,‎anuric‎renal‎failure‎after‎ atraumatic‎SSBU‎has‎been‎reported.(15) In‎the‎present‎study,‎90‎ureteral‎units‎with‎obstructive‎ure- teral‎ stones‎ were‎ evaluated.‎ The‎ intervention,‎ URSL‎ was‎ implemented‎ among‎ patients‎ without‎ changes‎ on‎ 12-lead‎ electrocardiography.(16)‎After‎single‎endoscopic‎procedure,‎a‎ stone-free‎rate‎was‎achieved‎in‎53‎(62%)‎ureteral‎units.‎Ap- proximately‎70%‎of‎the‎stones‎were‎located‎in‎the‎distal‎ure- ter.‎The‎procedure‎was‎successful‎for‎distal‎ureteric‎stones‎in‎ 73%.‎For‎patients‎with‎calculi‎less‎than‎10‎mm‎and‎greater‎ than‎10‎mm,‎the‎initial‎stone-free‎rate‎after‎ureteroscopy‎was‎ 70%‎and‎47%,‎respectively.‎As‎was‎shown‎by‎the‎results‎of‎ our‎study,‎the‎best‎candidates‎for‎urgent‎and‎bilateral‎same- session ureteroscopy are patients with distal ureteral stone. Thirty‎days‎after‎the‎initial‎procedure,‎in‎ureteral‎units‎with‎ ureteral‎stones‎up‎to‎10‎mm‎and‎localized‎in‎the‎distal‎ure- teral‎stones,‎ the‎SFR‎was‎93%.‎The‎American‎Urological‎ Association‎(AUA)‎ureteral‎stones‎clinical‎guidelines‎panel‎ and‎European‎Association‎of‎Urology‎(EAU)‎guidelines‎on‎ urolithiasis‎have‎reported‎that‎URSL‎stone-free‎rates‎(97%)‎ were‎better‎than‎SWL‎stone-free‎rates‎(86%)‎for‎distal‎ure- teral‎stones‎<‎10‎mm.(17)‎Ureteral‎stenting‎of‎patients‎with‎ multiple‎unilateral‎ (in‎ two‎distinct‎ locations)‎and‎bilateral‎ calculi‎appears‎to‎lessen‎the‎risk‎of‎a‎postoperative‎complica- tion.‎Protecting‎the‎urinary‎tree‎after‎a‎bilateral‎procedure‎DJ‎ ureteral‎stent‎placement‎seemed‎important‎to‎us;‎and‎added‎ little‎operative‎time‎to‎the‎procedure,‎although‎there‎was‎a‎ slight‎increase‎in‎postoperative‎discomfort‎and‎hematuria.‎An‎ important‎counterpoint‎is‎provided‎by‎the‎findings‎of‎Hollen- beck‎and‎colleagues,‎who‎noted‎that‎patients‎were‎70%‎more‎ likely‎to‎have‎postoperative‎complications‎when‎a‎ureteral‎ stent‎was‎not‎placed‎after‎treatment‎for‎bilateral‎or‎multiple‎ unilateral calculi.(18)‎AUA‎and‎EAU‎guidelines‎on‎urolithiasis‎ reported‎that‎stenting‎after‎uncomplicated‎URSL‎is‎optional,‎ but‎solitary‎kidney‎is‎one‎of‎the‎indications‎for‎stenting‎after‎ URSL.(17)‎Thus,‎while‎stent-free‎ureteroscopy‎has‎proven‎to‎ be‎safe‎after‎uncomplicated‎unilateral‎procedures,‎its‎role‎in‎ SSBU‎is‎less‎defined.(19)‎ The‎technique‎of‎ureteroscopy‎based‎on‎stone‎fragmentation‎ Table 4. Indicators of recovery of renal function on the 7th post-operative day in relation to duration of anuria prior to admission.* Variables Group A Group B P Diuresis < 2500 mL/24-hour 40 5 .0007 ≥ 2500 mL/24-hour 7 9 Serum creatinine (μmol/L) 50-110 44 6 .0001 ≥110 3 8 * Group A, 47 (77%) patients with anuria time of < 48-hour; Group B, 14 (23%) patients with anuria time of > 48-hour. 1398 | Endourology and Stone Disease with‎the‎electropneumatic‎generator,‎Lithotron‎Walz‎EL-27‎ Compact‎produces‎larger‎fragments‎(3-4‎mm)‎that‎may‎po- tentially‎cause‎problems‎in‎ terms‎of‎spontaneous‎passage.‎ Some‎authors‎recommend‎using‎forceps‎to‎reduce‎re-treat- ment‎rate.(20)‎Similarly,‎in‎this‎study,‎stone‎forceps‎were‎used‎ to‎remove‎stone‎fragments‎≥‎2‎mm‎in‎59‎(65.5%)‎of‎UU‎to‎ reduce‎the‎risk‎of‎a‎second‎or‎auxiliary‎procedure.‎ ‎Our‎attitude‎to‎routinely‎placement‎of‎ureteral‎stent,‎primar- ily‎for‎drainage‎of‎urine‎may‎be‎corrected‎in‎the‎future‎in‎the‎ sense‎that‎the‎surgeon‎is‎provided‎with‎a‎choice,‎to‎stent‎or‎ not‎to‎stent‎after‎SSBU.‎The‎selective‎use‎of‎stents‎accord- ing‎to‎surgeon‎preference‎made‎it‎challenging‎to‎determine‎ their‎role‎in‎SSBU.‎However,‎the‎decision‎to‎stent‎placement‎ was‎left‎to‎the‎attending‎urologist’s‎discretion.‎The‎perceived‎ complexity‎of‎the‎case‎was‎undoubtedly‎related‎to‎the‎deci- sion to stent. Open‎surgery‎was‎required‎for‎two‎of‎our‎patients‎(3.3%)‎ with‎ large,‎hard‎stones.‎PCN‎was‎performed‎as‎an‎urgent‎ treatment.‎Ureterolithotomy‎was‎done‎(in‎two‎patients,‎i.e.‎ two‎ units‎ of‎ bilateral‎ ureteral‎ calculi)‎ 6‎ to‎ 8‎ weeks‎ after‎ the‎ primary‎ intervention‎ (URSL+PCN).‎ Sharma‎ and‎ col- leagues(21)‎reported‎that‎open‎mini-access‎ureterolithotomy‎ is‎a‎safe‎and‎reliable‎minimally-invasive‎procedure;‎its‎role‎ is‎mainly‎confined‎to‎salvage‎for‎failed‎first-line‎stone‎treat- ments.‎In‎selected‎cases,‎however,‎where‎a‎poor‎outcome‎can‎ be‎predicted‎from‎other‎methods,‎it‎is‎an‎excellent‎first-line‎ treatment.‎ Calculus‎anuria‎is‎a‎urological‎emergency.‎Management‎in‎ form‎of‎urinary‎diversion‎and‎definite‎surgical‎treatment‎can‎ save‎the‎patient‎from‎developing‎chronic‎renal‎failure.(22) Al- though‎the‎need‎for‎rapid‎management‎of‎ureteral‎stones‎has‎ been‎accepted,‎the‎best‎modality‎of‎treatment‎is‎still‎a‎matter‎ of‎debate.‎The‎best‎procedure‎to‎choose‎is‎dependent‎on‎sev- eral‎factors,‎besides‎stone‎size‎and‎location,‎including‎the‎op- erator’s‎experience,‎patient‎preference,‎available‎equipment‎ and related costs.(23)‎Finally,‎there‎is‎still‎no‎consensus‎on‎ single-session‎URSL‎for‎the‎management‎of‎bilateral‎ureteric‎ stones‎and‎the‎use‎of‎postoperative‎stents‎is‎still‎controver- sial. Limitations‎of‎our‎study‎are‎that‎it‎is‎retrospective,‎non-ran- domized‎and‎that‎no‎comparison‎with‎a‎control‎group‎was‎ done.‎Patients‎presenting‎ in‎ the‎same‎manner‎ (anuria‎due‎ to‎ureteral‎stone)‎who‎were‎initially‎managed‎with‎PCN‎or‎ stents‎are‎not‎a‎good‎comparison‎group,‎because‎the‎only‎ad- dressed anuria, not calculosis. CONCLUSION The‎presented‎results‎suggest‎that‎urgent‎ureteroscopic‎litho- tripsy,‎URSL,‎is‎the‎method‎of‎choice‎for‎patients‎with‎re- nal‎calculi‎and‎anuria.‎The‎reasons‎for‎this‎conclusion‎are,‎ the‎method‎preserves‎renal‎function,‎which‎is‎achieved‎via‎ controlled‎relief‎of‎obstruction‎with‎establishment‎of‎prompt‎ diuresis,‎it‎provides‎a‎high‎stone-free‎rate‎for‎patients‎with‎ distal‎calculus‎location,‎and‎there‎is‎small‎number‎of‎rela- tively‎ mild‎ post-operative‎ complications.‎ The‎ question‎ is‎ raised‎as‎to‎whether‎routine‎stent‎placement‎is‎indicated‎post- procedurally. Table 5. Treatment modalities in relation to ureteral units. Type of Treatment Ureteral Units, no. (%) URSL + Ureteral stent 73 (81.1) URSL + DJ stent + SWL 15 (24.6) URSL + PCN + OP 2 (2.2) Keys: URSL, ureteroscopic lithotripsy; DJ, double J; SWL, extracor- poreal shockwave lithotripsy; PCN, percutaneous nephrostomy; OP, open surgery. Table 6. Complications classified according to the modified Clavien system. CCS Grade Patients-Ureteral Units no. (%) Grade 1 Mucosal laceration 5 (8.2)-5 (5.6) Stone/fragment migration 12 (19.7)-12 (13.3) Fever 8 (13.1) Hematuria 3 (4.9) Renal colic 9 (14.8) Grade 2 Urinary tract infection 5 (8.2) Pyelonephritis 2 (3.3) Grade 3 Stent migration 1 (1.6) Key: CCS, Clavien-Dindo classification system. 1399Vol. 11 | No. 02 | March- April 2014 |U R O LO G Y J O U R N A L Management of Calculus Anuria Using TUL | Savic et al REFERENCES 1. James M, Pannu N. Methodological considerations for observa- tional studies of acute kidney injury using existing data sources. J Nephrol. 2009;22:295-305. 2. 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Ureteral stent- ing and urinary stone management: a systematic review. J Urol. 2008;179:424. 20. Gonen M, Cenker A, Istanbulluoglu O, Ozkardes H. Efficacy of dretler stone cone in the treatment of ureteral stones with pneu- matic lithotripsy. Urol Int. 2006;76:159-62. 21. Sharma DM, Maharaj D, Naraynsingh V. Open mini-access ureteroli- thotomy: the treatment of choice for the refractory ureteric stone? BJU Int. 2003;92:614-6. 22. Westenberg A, Harper M, Zafirakis H, Shah PJ. Bladder and renal stones: management and treatment. Hosp Med. 2002;63:34-41. 23. Autorino R, Osorio L, Lima EA. Rapid extracorporeal shock wave lith- otripsy for proximal ureteral calculi in colic versus noncolic patients. Eur Urol. 2007;52:1264-5. ACKNOWLEDGMENT The‎authors‎wish‎to‎thank‎Dr‎Karen‎Belkic‎for‎her‎careful‎ reading‎of‎the‎manuscript. CONFLICT OF INTEREST None declared.