Young Tae Moon

Treatment of Steinstrasse with Repeat Extracorporeal Shock Wave Lithotripsy: Experience with Piezoelectric Lithotriptor

Among 958 patients with renal stones who underwent extracorporeal shock wave lithotripsy (ESWL) monotherapy using an EDAP-LT01 piezoelectric lithotriptor steinstrasse developed in 55 (5.7%). Of these 55 cases stone fragments passed spontaneously in 35 (63.6%) and were treated successfully (no residual stone fragment in ureter) with repeat ESWL in 18 (32.8%). Only 2 patients (3.6%) required ureteroscopic management or open ureterolithotomy. Therefore, repeat ESWL is considered a good initial method to treat complicated steinstrasse.

Extracorporeal shock wave lithotripsy monotherapy: experience with piezoelectric second generation lithotriptor in 642 patients

Extracorporeal shock wave lithotripsy monotherapy was performed in 642 patients for 1 year with an EDAP-LT01 piezoelectric lithotriptor. Of 642 patients 398 completed extracorporeal shock wave lithotripsy treatment and 244 still are undergoing multiple extracorporeal shock wave lithotripsy sessions. The 398 patients had renal (64.6 per cent) or ureteral (35.4 per cent) stones 0.6 to 4.8 cm. in diameter (mean 1.4 cm.). No general or regional anesthesia was required except in 7 children. Among 398 patients who completed extracorporeal shock wave lithotripsy the rate free of stones was 73.4 per cent and the rate of clinically insignificant residual fragments was 12.8 per cent. The success rate (rate free of calculi plus that of clinically insignificant renal fragments) ranged from 95.6 per cent for stones 0.6 to 1.0 cm. in diameter to 52.6 per cent for stones larger than 3.0 cm. (mean 86.2 per cent). The number of treatment sessions in 343 patients with successful results increased in accordance with the stone size, with an average of 1.6 sessions. Double-J* stents were placed in 7 patients and ureteral catheterization was performed in 11 as post-extracorporeal shock wave lithotripsy adjunctive measures. The steinstrasse phenomenon was noted in 14 patients, of whom only 1 required Double-J stenting. There were no significant complications. Therefore, extracorporeal shock wave lithotripsy monotherapy with the piezoelectric lithotriptor is considered to be a safe and efficient outpatient procedure for the initial treatment of urinary stones regardless of stone sizes.

Impact of Changing Trends in Medical Therapy on Surgery for Benign Prostatic Hyperplasia Over Two Decades

Purpose Following the introduction of medical therapy for benign prostatic hyperplasia (BPH), we determined the effect of the change in trends in medical therapy on the indication and outcome of surgical intervention for BPH. Materials and Methods We compared the basic characteristics of, weight of resected tissue of, transfusions in, and postoperative complications of patients who underwent surgery between 1985 and 1989 (before the advent of medical therapy for BPH), between 1995 and 1999 (when medical therapy was developed and became widely used as alternative treatment), and between 2005 and 2009 (when medical therapy superseded surgical intervention to become first-line treatment and when combination therapy became widely adopted). Results At our institution, the mean age and BMI of patients increased over the past two decades (p<0.001). Hypertension, operation history, and other comorbidities also increased significantly (p<0.001, p=0.005, and p<0.001, respectively). The indications for surgery in 1985 to 1989, 1995 to 1999, and 2005 to 2009 were as follows: acute urinary retention in 34.7%, 20.2%, and 15.1% of patients and symptomatic deterioration in 61.1%, 72.3%, and 73.0% of patients, respectively. Prostate volume and the weight of resected tissue increased from 34.4±14.5 ml to 61.3±32.4 ml and from 7.2±6.4 g to 10.8±7.6 g, respectively, over two decades. Patients who underwent surgery in 2005 to 2009 had their catheters removed earlier (p<0.001). Secondary hemorrhage within four postoperative weeks and repeat transurethral resection of the prostate within 1 year decreased significantly (p=0.03 and p=0.003, respectively). No statistically significant change in impaired detrusor contractility was found (p=0.523). Conclusions Although patients who underwent surgery were older after widespread use of medical therapy for BPH, advancements in surgical techniques have benefitted these patients.

Possible Relationship between Metabolic Syndrome Traits and Nephrolithiasis: Incidence for 15 Years According to Gender

Purpose To analyze the independent effect of metabolic syndrome (MS) on nephrolithiasis (NL) despite differences in gender compared with the known lithogenic factors. Materials and Methods From 1995 to 2009, 40,687 Koreans were enrolled in the study and observed for the development of NL at a health promotion center. The examination included anthropometric and biochemical measurements as well as kidney ultrasonography. A students t-test or chi-square test was used to characterize the participants and a standard Cox proportional hazards model was used to calculate the adjusted odds ratio of lithogenic risk factors in the NL model. Results The mean age of the study cohort was 44.9 years (range, 13-100 years), and 22,540 (55.4%) of the cohort was male. The incidence of NL was 1.5% (609 participants), with males exhibiting a higher incidence than females (1.9% vs 1.0%, p<0.01). Among the total cohort, MS as well as each trait of MS were risk factors for NL. In males, high body mass index (BMI), high blood pressure, and abnormal glucose metabolism were significant lithogenic factors, whereas in females, lithogenic factors included only high BMI and abnormal glucose metabolism. Conclusions MS is a significant lithogenic factor compared with other lithogenic factors. There was a correlated change in the prevalence of MS and NL and MS traits in Korea.

Pilot Study of Low-Dose Nonenhanced Computed Tomography With Iterative Reconstruction for Diagnosis of Urinary Stones

Purpose To evaluate the efficacy of low-dose computed tomography (LDCT) for detecting urinary stones with the use of an iterative reconstruction technique for reducing radiation dose and image noise. Materials and Methods A total of 101 stones from 69 patients who underwent both conventional nonenhanced computed tomography (CCT) and LDCT were analyzed. Interpretations were made of the two scans according to stone characteristics (size, volume, location, Hounsfield unit [HU], and skin-to-stone distance [SSD]) and radiation dose by dose-length product (DLP), effective dose (ED), and image noise. Diagnostic performance for detecting urinary stones was assessed by statistical evaluation. Results No statistical differences were found in stone characteristics between the two scans. The average DLP and ED were 384.60±132.15 mGy and 5.77±1.98 mSv in CCT and 90.08±31.80 mGy and 1.34±0.48 mSv in LDCT, respectively. The dose reduction rate of LDCT was nearly 77% for both DLP and ED (p<0.01). The mean objective noise (standard deviation) from three different areas was 23.0±2.5 in CCT and 29.2±3.1 in LDCT with a significant difference (p<0.05); the slight increase was 21.2%. For stones located throughout the kidney and ureter, the sensitivity and specificity of LDCT remained 96.0% and 100%, with positive and negative predictive values of 100% and 96.2%, respectively. Conclusions LDCT showed significant radiation reduction while maintaining high image quality. It is an attractive option in the diagnosis of urinary stones.

Predicting Recurrence and Progression of Non-Muscle-Invasive Bladder Cancer in Korean Patients: A Comparison of the EORTC and CUETO Models

Purpose This study aimed to confirm the utility of the European Organization for Research and Treatment of Cancer (EORTC) and the Spanish Urological Club for Oncological Treatment (CUETO) scoring systems and to determine which model is preferred as a prognostic model in Korean patients with non-muscle-invasive bladder cancer. Materials and Methods Between 1985 and 2011, 531 patients who were treated by transurethral resection of bladder cancer were retrospectively analyzed by use of the EORTC and CUETO models. Statistically, we performed Kaplan-Meier survival analysis; calculated Harrells concordance index, receiver operating characteristic (ROC) curve, and cutoff values; and performed univariate and multivariate Cox proportional hazards regression analyses. Results For risk of recurrence, with the use of the EORTC model, all groups had statistically significant differences except between the group with a score of 0 and the group with a score of 1-4. With the use of the CUETO model, all groups differed significantly. For risk of progression, with the use of the EORTC model, significant differences were observed between all groups except between the group with a score of 2-6 and the group with a score of 7-13. With the use of the CUETO model, a significant difference was observed between the group with a score of 0 and the other groups. The concordance index of the EORTC and CUETO models was 0.759 and 0.836 for recurrence and 0.704 and 0.745 for progression, respectively. The area under the ROC curve for the EORTC and CUETO models was 0.832 and 0.894 for recurrence and 0.722 and 0.724 for progression, respectively. Conclusions Both scoring systems, especially the CUETO model, showed value in predicting recurrence and progression in Korean patients, which will help in individualizing treatment and follow-up schedules.

Evaluation of the Optimal Frequency of and Pretreatment with Shock Waves in Patients with Renal Stones

Purpose Many studies have been carried out to increase the success rate of shock wave lithotripsy (SWL) and to reduce renal injury. We investigated the success rate after one session as well as urine N-acetyl-β-d-glucosaminidase (NAG) levels for the evaluation of renal injury according to shock wave frequency and pretreatment with low-energy shock waves during SWL. Materials and Methods The study targeted 48 patients with renal stones who had undergone SWL. Patients were sequentially allocated into four groups according to shock wave frequency (60 or 120 shocks/min) and whether pretreatment had occurred. We documented total SWL operating number, success rate after first SWL, urine NAG, compliance, and the total cost for each patient. Results There were 32 males and 16 females with an average age of 51.6 years. The average stone size was 7.06 mm, and there was no significant difference in stone size between the groups. The data showed that patients treated with a frequency of 60 shocks/min had a lower mean number of SWL sessions, 1.36 sessions for 60 shocks/min and 2.0 sessions for 120 shocks/min, respectively, which was statistically significant (p<0.05). When comparing NAG/creatinin ratios before and after SWL between those with and without pretreatment, there was no significant difference according to pretreatment (p=0.406). Conclusions SWL treatment at a frequency of 60 shocks/min yielded better outcomes, such as a lower number of SWL sessions, and had an increased success rate compared with SWL at 120 shocks/min. On the other hand, pretreatment did not impact renal injury. Therefore, SWL treatment at a frequency of 60 shocks/min could improve treatment efficacy more than that for SWL at 120 shocks/min.

NS-398 (a Selective Cyclooxygenase-2 Inhibitor) Decreases Agonist-Induced Contraction of the Human Ureter via Calcium Channel Inhibition

PURPOSE Recently, it has been demonstrated that ureteral obstruction is associated with increased cyclooxygenase (COX)-2 expression and that selective COX-2 inhibitors provide potent analgesia with fewer side effects in patients with ureteral stones. Moreover, selective COX-2 inhibitors have been shown to decrease in vitro contractility of the human ureter. We aimed at evaluating the effects of the selective COX-2 inhibitor NS-398 on human ureteral smooth muscle contractility and compare its potency with that of nonselective COX inhibitors, COX-1 inhibitors, and other COX-2 inhibitors. MATERIALS AND METHODS Ureteral samples were obtained from human adult subjects undergoing radical nephrectomy. After isolating the upper ureteral strips, we analyzed the contractile responses of the ureteral strips to high potassium (KCl 35 mM) and Bay K 8644 and the relaxation responses of a nonspecific COX inhibitor (indomethacin), a COX-1 inhibitor (SC-560), and a COX-2 inhibitor (NS-398 and celecoxib) to KCl and Bay K 8644-induced contraction by measuring isometric tension. RESULTS NS-398 produced dose-dependent (10⁻⁹-10⁻⁵ M) relaxation of KCl (35 mM)-precontracted strips of the ureter, whereas indomethacin (10⁻⁸-10⁻⁵ M) and SC-560 (10⁻⁹-10⁻⁵ M) did not. Both tonic and phasic contraction of Bay K 8644 (methyl-1,4-dihydro-2,6-dimethyl-3-nitro-4-2(trifluoromethylphenyl)pyridine-5-carboxylate) (1 μM) were significantly inhibited by NS-398 (10⁻⁵ M). Another selective COX-2 inhibitor, celecoxib, did not show potent inhibitory effects as strong as those of NS-398. CONCLUSIONS We concluded that NS-398 reduces tonic or phasic contraction by inhibiting the action of voltage-dependent calcium channels. NS-398 has dual inhibitory effects with COX-2 inhibition on ureteral spasms due to renal or ureteral colic.

The Unintubated Ureterotomy Endourologically Revisited

PURPOSE The duration of stenting after endoureterotomy is a controversial issue. An even more basic question, however, is whether stent placement is needed at all. We performed a porcine study to address this question. METHODS A unilateral midureteral stricture was created in 20 minipigs. Six weeks later, 15 pigs underwent endoureterotomy. In 10 animals, a 7F ureteral stent was placed for 1 week. Five pigs remained unstented. Three months later, all 20 ureters were studied radiographically and were harvested. RESULTS Three of 5 control animals and 2 of 10 stented animals has strictures. In the unstented study group, all 5 animals had a nonobstructing dilation at the site of endoureterotomy. This was corroborated by a normal furosemide washout renal scan in all 3 animals so tested. CONCLUSIONS The result of unstented endoureterotomy in the porcine model suggests that, after endoureterotomy of secondary midureteral strictures, stenting may be unnecessary.

Febrile urinary tract infection after prostate biopsy and quinolone resistance.

Purpose Complications after prostate biopsy have increased and various causes have been reported. Growing evidence of increasing quinolone resistance is of particular concern. In the current retrospective study, we evaluated the incidence of infectious complications after prostate biopsy and identified the risk factors. Materials and Methods The study population included 1,195 patients who underwent a prostate biopsy between January 2007 and December 2012 at Chung-Ang University Hospital. Cases of febrile UTI that occurred within 7 days were investigated. Clinical information included age, prostate-specific antigen, prostate volume, hypertension, diabetes, body mass index, and biopsy done in the quinolone-resistance era. Patients received quinolone (250 mg intravenously) before and after the procedure, and quinolone (250 mg) was orally administered twice daily for 3 days. We used univariate and multivariate analysis to investigate the predictive factors for febrile UTI. Results Febrile UTI developed in 39 cases (3.1%). Core numbers increased from 2007 (8 cores) to 2012 (12 cores) and quinolone-resistant bacteria began to appear in 2010 (quinolone-resistance era). In the univariate analysis, core number≥12 (p=0.024), body mass index (BMI)>25 kg/m2 (p=0.004), and biopsy done in the quinolone-resistance era (p=0.014) were significant factors. However, in the multivariate analysis adjusted for core number, the results were not significant, with the exception of BMI>25 kg/m2 (p=0.011) and biopsy during the quinolone-resistance era (p=0.035), which were significantly associated with febrile UTI. Conclusions Quinolone resistance is the main cause of postbiopsy infections in our center. We suggest that further evaluation is required to validate similar trends. Novel strategies to find alternative prophylactic agents are also necessary.