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1836 QUANTITATIVE ASSESSMENT OF SHOCKWAVE LITHOTRIPSY ACCURACY
e736
THE JOURNAL OF UROLOGY姞
CONCLUSIONS: Early SWL group required lesser number of SWL sessions and showed shorter time taken for stone clearance than late SWL group. Source of Funding: None
1835 DOES THE X-RAY TECHNOLOGIST OR AMOUNT FLUOROSCOPY TIME EFFECT TREATMENT SUCCESS WITH EXTRACORPOREAL SHOCKWAVE LITHOTRIPSY? Michael Ordon*, Daniela Ghiculete, Joshua D. Wiesenthal, Kenneth T. Pace, R. John D’A Honey, Toronto, Canada INTRODUCTION AND OBJECTIVES: The minimally invasive nature and effectiveness of Extracorporeal Shockwave Lithotripsy (SWL) has made it one of the primary treatment modalities for urinary tract calculi. Several factors determining the success of SWL treatment have been studied including stone factors (i.e., location, size, and composition) and patient factors (i.e., patient habitus and skin-to-stone distance). Furthermore, treating urologist has also been shown to effect treatment outcome. Our objective was to determine if either the assisting X-ray technologist or the amount of fluoroscopy time used had an impact on SWL success. METHODS: We compared the outcome of 283 SWL treatments across three X-ray technologists. We also evaluated the average amount of fluoroscopy time used in treatment success versus failures in this same cohort. The outcome measured was stone free rate and success at 2 weeks and 3 months. Success was defined as being either stone free, having residual sand or an asymptomatic fragment ⬍4mm on KUB x-ray. RESULTS: The patients treated by the three different X-ray technologists were comparable with respect to BMI, stone side and location, presence of ureteric stent and mean stone area (mm2). The stone free and success rate at 2 weeks and 3 months between the three X-ray technologists were not significantly different. When examining fluoroscopy time, we found a significantly greater mean fluoroscopy time was used in the treatment successes at 2 weeks (3.03 min vs. 2.62 min, p⫽0.005) and 3 months (2.97 min vs. 2.66 min, p⫽0.03) compared to treatment failures. CONCLUSIONS: X-ray technologist did not have a significant impact on SWL treatment outcome at 2 weeks and 3 months. However, SWL treatment success at 2 weeks and 3 months was associated with a greater amount of fluoroscopy time suggesting using fluoroscopy to ensure accurate targeting during SWL is important for success. Source of Funding: None
1836 QUANTITATIVE ASSESSMENT OF SHOCKWAVE LITHOTRIPSY ACCURACY Anup Shah*, Jonathan D. Harper, Jonathan L. Wright, Mathew D. Sorensen, Marla Paun, Michael R. Bailey, Seattle, WA INTRODUCTION AND OBJECTIVES: Effective stone comminution during shock wave lithotripsy (SWL) is dependent on precise three dimensional targeting of the shock wave focal point. Respiratory motion, imprecise shock wave alignment, and stone movement during treatment may compromise treatment efficacy. The objective of this study is to describe the novel use of ultrasound imaging to evaluate the accuracy of shock wave targeting during SWL treatment. METHODS: Patients undergoing SWL treatment were enrolled into this institutionally approved research study. A Healthtronics Lithotron fluoroscopically targeted and delivered shockwave treatment to renal stones. A commercial diagnostic ultrasound imaging system, either Phillips HDI 5000 or iU-22, was used to intermittently visualize and detect any shockwave-induced motion of the targeted renal stone during 1–3 minute periods. Stone motion in the form of oscillation or jumping was interpreted as an accurate alignment of the shockwave focus onto the stone.
Vol. 185, No. 4S, Supplement, Tuesday, May 17, 2011
RESULTS: Four patients (mean age 52.7) underwent treatment of seven renal stones with mean individual stone size of 10.41⫹/⫺ 4.5 mm. A mean of 2937 shocks (range 2750 –3000) were delivered at a rate of 1–2 Hz and energy of 14 –26 kV. Stone oscillation or jumping at the exact time of individual shock delivery was visualized with ultrasound: no stones completely failed to move. Accurate alignment, as interpreted by positive stone motion, occurred in a mean of 50 ⫹/⫺ 20.4% of shockwaves. CONCLUSIONS: Efficacy of SWL treatment may be compromised by misalignment in shock wave focus due to stone movement during treatment. Ultrasound imaging represents a novel way of real time assessment of accuracy in shockwave delivery. This may provide the basis for devices to control targeting so that shockwaves are only delivered when the stone is in focus. Source of Funding: NIH DK48331 NIH DK086371
1837 SHOCKWAVE LITHOTRIPSY: IS ITS CURRENT EFFICACY OVERESTIMATED? AN INVESTIGATION OF SUCCESS AND RETREATMENT FOR BOTH FIRST- AND FOURTH-GENERATION LITHOTRIPTERS Brian Benway*, Timur Roytman, Robert Figenshau, Sam Bhayani, Alana Desai, St. Louis, MO INTRODUCTION AND OBJECTIVES: Shockwave lithotripsy (SWL) is one accepted modality for the treatment of renal and ureteral calculi, with reported success rates historically on par with ureteroscopic intervention. However, at our institution, we have witnessed what we believe to be a sharp decrease in efficacy of SWL for stones ⬍1.5cm. We therefore sought to evaluate contemporary outcomes of SWL performed with both first- and fourth-generation lithotripters from January 2007 through January 2009. METHODS: An interim analysis of patients undergoing SWL between 2007 and 2009 was performed. Only patients with follow-up at our institution were included. Of the 53 patients who met inclusion criteria, 26 patients were treated with the first-generation Dornier HM3 lithotripter, and 27 were treated using the fourth-generation Storz Modulith F2. Outcomes, including stone clearance, postoperative complications, and retreatments were evaluated. RESULTS: The two patient populations were equivalent across all measured demographic parameters, including age, BMI, comorbidity, stone size, and composition. Mean stone size for the HM3 group was 12.1mm, and 11.5 for the F2 cohort (p⫽0.7). Stone composition was predominantly calcium oxalate monohydrate. Skin-to-stone distance for HM3 and F2 was 12.5 and 11.4cm, respectively (p⫽0.3). Success, as determined by residual fragment size ⬍2 mm was 47% for the HM3 and 39% for the F2; this difference was not statistically significant (p⫽0.6). 27% of HM3 and 19% of F2 patients required emergent evaluation or re-admission. Retreatment was required in 50% and 52% of patients treated with the HM3 and F2, respectively (p⫽0.5). CONCLUSIONS: In our sampling analysis, SWL in the modern era appears to be associated with a marked decrease in efficacy over historically-reported outcomes, with half of patients now requiring retreatment. Even more surprisingly, this decline appears to be independent of lithotripter generation, suggesting perhaps that changes in patient characteristics and stone composition, and not technology may be to blame. Further study is critically needed. Source of Funding: Midwest Stone Institute
THE JOURNAL OF UROLOGY姞
CONCLUSIONS: Early SWL group required lesser number of SWL sessions and showed shorter time taken for stone clearance than late SWL group. Source of Funding: None
1835 DOES THE X-RAY TECHNOLOGIST OR AMOUNT FLUOROSCOPY TIME EFFECT TREATMENT SUCCESS WITH EXTRACORPOREAL SHOCKWAVE LITHOTRIPSY? Michael Ordon*, Daniela Ghiculete, Joshua D. Wiesenthal, Kenneth T. Pace, R. John D’A Honey, Toronto, Canada INTRODUCTION AND OBJECTIVES: The minimally invasive nature and effectiveness of Extracorporeal Shockwave Lithotripsy (SWL) has made it one of the primary treatment modalities for urinary tract calculi. Several factors determining the success of SWL treatment have been studied including stone factors (i.e., location, size, and composition) and patient factors (i.e., patient habitus and skin-to-stone distance). Furthermore, treating urologist has also been shown to effect treatment outcome. Our objective was to determine if either the assisting X-ray technologist or the amount of fluoroscopy time used had an impact on SWL success. METHODS: We compared the outcome of 283 SWL treatments across three X-ray technologists. We also evaluated the average amount of fluoroscopy time used in treatment success versus failures in this same cohort. The outcome measured was stone free rate and success at 2 weeks and 3 months. Success was defined as being either stone free, having residual sand or an asymptomatic fragment ⬍4mm on KUB x-ray. RESULTS: The patients treated by the three different X-ray technologists were comparable with respect to BMI, stone side and location, presence of ureteric stent and mean stone area (mm2). The stone free and success rate at 2 weeks and 3 months between the three X-ray technologists were not significantly different. When examining fluoroscopy time, we found a significantly greater mean fluoroscopy time was used in the treatment successes at 2 weeks (3.03 min vs. 2.62 min, p⫽0.005) and 3 months (2.97 min vs. 2.66 min, p⫽0.03) compared to treatment failures. CONCLUSIONS: X-ray technologist did not have a significant impact on SWL treatment outcome at 2 weeks and 3 months. However, SWL treatment success at 2 weeks and 3 months was associated with a greater amount of fluoroscopy time suggesting using fluoroscopy to ensure accurate targeting during SWL is important for success. Source of Funding: None
1836 QUANTITATIVE ASSESSMENT OF SHOCKWAVE LITHOTRIPSY ACCURACY Anup Shah*, Jonathan D. Harper, Jonathan L. Wright, Mathew D. Sorensen, Marla Paun, Michael R. Bailey, Seattle, WA INTRODUCTION AND OBJECTIVES: Effective stone comminution during shock wave lithotripsy (SWL) is dependent on precise three dimensional targeting of the shock wave focal point. Respiratory motion, imprecise shock wave alignment, and stone movement during treatment may compromise treatment efficacy. The objective of this study is to describe the novel use of ultrasound imaging to evaluate the accuracy of shock wave targeting during SWL treatment. METHODS: Patients undergoing SWL treatment were enrolled into this institutionally approved research study. A Healthtronics Lithotron fluoroscopically targeted and delivered shockwave treatment to renal stones. A commercial diagnostic ultrasound imaging system, either Phillips HDI 5000 or iU-22, was used to intermittently visualize and detect any shockwave-induced motion of the targeted renal stone during 1–3 minute periods. Stone motion in the form of oscillation or jumping was interpreted as an accurate alignment of the shockwave focus onto the stone.
Vol. 185, No. 4S, Supplement, Tuesday, May 17, 2011
RESULTS: Four patients (mean age 52.7) underwent treatment of seven renal stones with mean individual stone size of 10.41⫹/⫺ 4.5 mm. A mean of 2937 shocks (range 2750 –3000) were delivered at a rate of 1–2 Hz and energy of 14 –26 kV. Stone oscillation or jumping at the exact time of individual shock delivery was visualized with ultrasound: no stones completely failed to move. Accurate alignment, as interpreted by positive stone motion, occurred in a mean of 50 ⫹/⫺ 20.4% of shockwaves. CONCLUSIONS: Efficacy of SWL treatment may be compromised by misalignment in shock wave focus due to stone movement during treatment. Ultrasound imaging represents a novel way of real time assessment of accuracy in shockwave delivery. This may provide the basis for devices to control targeting so that shockwaves are only delivered when the stone is in focus. Source of Funding: NIH DK48331 NIH DK086371
1837 SHOCKWAVE LITHOTRIPSY: IS ITS CURRENT EFFICACY OVERESTIMATED? AN INVESTIGATION OF SUCCESS AND RETREATMENT FOR BOTH FIRST- AND FOURTH-GENERATION LITHOTRIPTERS Brian Benway*, Timur Roytman, Robert Figenshau, Sam Bhayani, Alana Desai, St. Louis, MO INTRODUCTION AND OBJECTIVES: Shockwave lithotripsy (SWL) is one accepted modality for the treatment of renal and ureteral calculi, with reported success rates historically on par with ureteroscopic intervention. However, at our institution, we have witnessed what we believe to be a sharp decrease in efficacy of SWL for stones ⬍1.5cm. We therefore sought to evaluate contemporary outcomes of SWL performed with both first- and fourth-generation lithotripters from January 2007 through January 2009. METHODS: An interim analysis of patients undergoing SWL between 2007 and 2009 was performed. Only patients with follow-up at our institution were included. Of the 53 patients who met inclusion criteria, 26 patients were treated with the first-generation Dornier HM3 lithotripter, and 27 were treated using the fourth-generation Storz Modulith F2. Outcomes, including stone clearance, postoperative complications, and retreatments were evaluated. RESULTS: The two patient populations were equivalent across all measured demographic parameters, including age, BMI, comorbidity, stone size, and composition. Mean stone size for the HM3 group was 12.1mm, and 11.5 for the F2 cohort (p⫽0.7). Stone composition was predominantly calcium oxalate monohydrate. Skin-to-stone distance for HM3 and F2 was 12.5 and 11.4cm, respectively (p⫽0.3). Success, as determined by residual fragment size ⬍2 mm was 47% for the HM3 and 39% for the F2; this difference was not statistically significant (p⫽0.6). 27% of HM3 and 19% of F2 patients required emergent evaluation or re-admission. Retreatment was required in 50% and 52% of patients treated with the HM3 and F2, respectively (p⫽0.5). CONCLUSIONS: In our sampling analysis, SWL in the modern era appears to be associated with a marked decrease in efficacy over historically-reported outcomes, with half of patients now requiring retreatment. Even more surprisingly, this decline appears to be independent of lithotripter generation, suggesting perhaps that changes in patient characteristics and stone composition, and not technology may be to blame. Further study is critically needed. Source of Funding: Midwest Stone Institute