U J 03 - All-2.pdf 549Vol. 9 | No. 3 | Summer 2012 |U R O LO G Y J O U R N A L Department of Urology, Osaka Medical College, Osaka, Japan Kiyoshi Takahara, Naokazu Ibuki, Teruo Inamoto, Hayahito Nomi, Takanobu Ubai, Haruhito Azuma Predictors of Success for Stone Fragmen- tation and Stone-Free Rate After Extra- corporeal Shockwave Lithotripsy in the Treatment of Upper Urinary Tract Stones Corresponding Author: Kiyoshi Takahara, MD Department of Urology, Osaka Medical College, 2-7 Daigaku-machi, Takat- suki City, Osaka, 569-8686, Japan Tel: +72 683 1221 Fax: +72 684 6546 E-mail: uro037@poh. osaka-med.ac.jp Received December 2011 Accepted January 2012 Purpose: To evaluate factors affecting the success rate of stone fragmentation and stone-free rate Materials and Methods: treatment. Results: - P P - the stone-free rate (middle: P = .0229). Conclusion: Our study suggests that stone fragmentation and stone-free rate after SWL treatment for upper urinary tract stones can be predicted. Keywords: - ment outcome BRIEF COMMUNICATION 550 | INTRODUCTION Renal and ureteral stones are common urological for treatment of upper urinary tract stones. Several factors SWL treatment for renal(1,2) and ureteral stones,(3,4) includ- gender, and stone features, such as stone site and size. predict stone fragmentation after SWL for upper urinary - selected for assessment. MATERIALS AND METHODS 2), respectively. - and 45, respectively. - - - P RESULTS - tation. The success of stone fragmentation for each factor is - cess rate (P P Brief Communication Table 1. Factors affecting stone fragmentation. Variable Success, n (%) P Odds ratio Body mass index, kg/m2 25 < 25 18/30 (60%) 71/91 (78%) .04 2.745 Stone size, mm Small (0 to 15) Medium (16 to 25) Large (> 25) 59/80 (73.8%) 22/31 (71.0%) 8/10 (80.0%) .3556 .5225 0.611 0.553 Stone position R2 R3 U1 42/48 (87.5%) 9/11 (81.8%) 38/62 (61.3%) .5054 .0108 0.517 0.167 Hydronephrosis Yes No 52/76 (68.4%) 37/45 (82.2%) .8731 1.109 R2 indicates renal pelvis and calices; R3, ureteropelvic junction; and U1, upper ureter. 551Vol. 9 | No. 3 | Summer 2012 |U R O LO G Y J O U R N A L - on the stone-free rate (middle: P = .0229). DISCUSSION as the preferred method for treating upper urinary tract (1-4) An ideal method for stone therapy should provide high ef- (5) - ple, immediate stone-free rate can not be achieved after SWL, and some patients may need repeated treatment due to stone recurrence.(6) Therefore, determining the patients and colleagues constructed pre-operative nomograms for predicting stone-free rates after single SWL treatment, and (7) - cess of stone fragmentation and stone-free rate. - pendent predictors of stone-free rate after SWL. A successful P < .01). - clinical outcome of SWL treatment. Stone size has been - nal stones.(1,2) prognostic factors that affect the success rate after SWL - - P < .001).(1) P < .05).(2) - Predicting Stone Fragmentation in SWL | Takahara et al Table 2. Factors affecting stone-free rate. Variable Success, n (%) P Odds ratio Body mass index, kg/m2 ≥ 25 < 25 10/15 (66.7%) 41/56 (73.2%) .5297 1.549 Stone size, mm Small (0 to 15) Medium (16 to 25) Large (> 25) 39/49 (79.6%) 7/16 (43.8%) 5/6 (83.3%) .0229 .5923 0.205 1.881 Stone position R2 R3 U1 20/32 (62.5%) 6/9 (66.7%) 25/30 (83.3%) .8269 .4326 0.517 0.167 Hydronephrosis Yes No 32/42 (76.2%) 19/29 (65.5%) .5496 1.611 SWL treatment times 1 > 2 47/61 (77%) 4/10 (40%) .06745 0.705 R2 indicates renal pelvis and calices; R3, ureteropelvic junction; U1, upper ureter; and SWL, extracorporeal shockwave lithotripsy. 552 | strongest independent predictors of failure for SWL treat- (3) the clinical outcome of SWL treatment [success: 1.00 cm (0.90 to 1.10) and failure: 1.30 cm (1.10 to 1.60); P < .001]. (4) - - cated that after successful stone fragmentation, only stone higher for pelvic and upper calyceal stones compared to (1,9-11) - erally considered to be the reason for the superior success rates, but the multivariate analyses indicated that ureteral clinical outcome.(4,12) stone fragmentation and stone-free rate. Stone location sig- Previous research has indicated that hydronephrosis has a (13) - cess for both stone fragmentation and stone-free status after SWL treatment. CONCLUSION success for stone fragmentation and stone-free rate, sepa- rately. Our analysis indicated that different factors affect stone fragmentation and stone-free rate. CONFLICT OF INTEREST None declared. REFERENCES 1. Abdel-Khalek M, Sheir KZ, Mokhtar AA, Eraky I, Kenawy M, Bazeed M. Prediction of success rate after extracorporeal shock-wave lithotripsy of renal stones--a multivariate analysis model. Scand J Urol Nephrol. 2004;38:161-7. 2. Al-Ansari A, As-Sadiq K, Al-Said S, Younis N, Jaleel OA, Shokeir AA. Prognostic factors of success of extracorporeal shock wave lithotripsy (ESWL) in the treatment of renal stones. Int Urol Nephrol. 2006;38:63-7. 3. Delakas D, Karyotis I, Daskalopoulos G, Lianos E, Mavro- manolakis E. Independent predictors of failure of shock- wave lithotripsy for ureteral stones employing a second- generation lithotripter. J Endourol. 2003;17:201-5. 4. Wang M, Shi Q, Wang X, Yang K, Yang R. Prediction of outcome of extracorporeal shock wave lithotripsy in the management of ureteric calculi. Urol Res. 2011;39:51-7. 5. Augustin H. Prediction of stone-free rate after ESWL. Eur Urol. 2007;52:318-20. 6. Sun BY, Lee YH, Jiaan BP, Chen KK, Chang LS, Chen KT. Recurrence rate and risk factors for urinary calculi after extracorporeal shock wave lithotripsy. J Urol. 1996;156:903- 5; discussion 6. 7. Kanao K, Nakashima J, Nakagawa K, et al. Preoperative nomograms for predicting stone-free rate after extracor- poreal shock wave lithotripsy. J Urol. 2006;176:1453-6; discussion 6-7. 8. Pareek G, Armenakas NA, Panagopoulos G, Bruno JJ, Fracchia JA. Extracorporeal shock wave lithotripsy success based on body mass index and Hounsfield units. Urology. 2005;65:33-6. 9. Zanetti G, Montanari E, Mandressi A, et al. Long-term re- sults of extracorporeal shock wave lithotripsy in renal stone treatment. J Endourol. 1991;5:61-4. 10. Rassweiler J, Köhrmann KU, Alken P. ESWL, including imag- ing. Curr Opin Urol. 1992;2:291-9. 11. Tolon M, Miroglu C, Erol H, et al. A report on extracorporeal shock wave lithotripsy results on 1,569 renal units in an outpatient clinic. J Urol. 1991;145:695-8. 12. Gnanapragasam VJ, Ramsden PD, Murthy LS, Thomas DJ. Primary in situ extracorporeal shock wave lithotripsy in the management of ureteric calculi: results with a third-gener- ation lithotripter. BJU Int. 1999;84:770-4. 13. Turna B, Akbay K, Ekren F, et al. Comparative study of ex- tracorporeal shock wave lithotripsy outcomes for proximal and distal ureteric stones. Int Urol Nephrol. 2008;40:23-9. Brief Communication 553Vol. 9 | No. 3 | Summer 2012 |U R O LO G Y J O U R N A L Urology and Nephrology Research Center, Shohada- e-Tajrish Medical Center, Shahid Beheshti University of Medical Sciences, Teh- ran, Iran Hossein Karami, Alireza Rezaei, Mohammad Mohsen Mazloomfard, Babak Javanmard, Behzad Lotfi, Amir Haji-Mohammadmehdi-Arbab Effects of Surgical Position on Patients’ Arterial Blood Gases During Percutaneous Nephrolithotomy Corresponding Author: Mohammad Mohsen Mazloomfard, MD Urology and Nephrology Research Center, No.103, 9th Boustan St., Pasdaran Ave., Tehran, Iran Tel: +98 21 2256 7222 Fax: +98 21 2277 0954 E-mail: mazloomfard@ yahoo.com Received August 2010 Accepted January 2012 ENDOUROLOGY AND STONE DISEASE Purpose: - Materials and Methods: - - repositioning. Results : and supine positions, respectively (P 2 P = .21). Arterial oxygen pressure (PaO2 P = .01) and P P 2 3 prone, and supine groups. Conclusion: Keywords: percutaneous nephrolithotomy, blood gas analysis, prone position