International Kidney Stone Institute

Our purpose here is to test the hypothesis that Randall's plaques, calcium phosphate deposits in kidneys of patients with calcium renal stones, arise in unique anatomical regions of the kidney, their formation conditioned by specific stone-forming pathophysiologies. To test this hypothesis, we performed intraoperative biopsies of plaques in kidneys of idiopathic-calcium-stone formers and patients with stones due to obesity-related bypass procedures and obtained papillary specimens from non-stone formers after nephrectomy. Plaque originates in the basement membranes of the thin loops of Henle and spreads from there through the interstitium to beneath the urothelium. Patients who have undergone bypass surgery do not produce such plaque but instead form intratubular hydroxyapatite crystals in collecting ducts. Non-stone formers also do not form plaque. Plaque is specific to certain kinds of stone-forming patients and is initiated specifically in thin-limb basement membranes by mechanisms that remain to be elucidated.

Urolithiasis affects 5-15% of the population worldwide.1 w1 Recurrence rates are close to 50%,2 w2 and the cost of urolithiasis to individuals and society is high. Acute renal colic is a common presentation in general practice, so a basic understanding of its evaluation and treatment would be useful. Most of the literature is retrospective, but we will try to provide an evidence based review of the management of urolithiasis and will cite prospective randomised controlled trials when available. #### Summary points #### Sources and selection criteria Initial evaluation of the patient with urolithiasis should include a complete medical history and physical examination. Typical symptoms of acute renal colic are intermittent colicky flank pain that may radiate to the lower abdomen or groin, often associated with nausea and vomiting.3 Lower urinary tract symptoms such as dysuria, urgency, and frequency may occur once a stone enters the ureter. Comorbid diseases should be identified, particularly any systemic illnesses that might increase the risk of kidney stone formation or that might influence the clinical course of the disease (box 1). Other important features are a …

PURPOSE: Holmium laser prostate enucleation is a contemporary treatment for benign prostatic hyperplasia. We report our experience with more than 1,000 procedures. MATERIALS AND METHODS: From June 1998 to March 2009 we performed 1,065 holmium laser prostate enucleations. After receiving institutional review board approval we retrospectively reviewed the database. Reported short-term, intermediate term and long-term results are 0 to 6, 6 to 12 and greater than 12 months, respectively. RESULTS: Bladder stones were present in 50 patients (4.7%) and 87 of the 717 (12.1%) with laboratory studies available had renal insufficiency. Preoperative urinary retention was present in 411 cases (38.7%). Significant preoperative stress and urge incontinence was noted in 8 and 16 patients, respectively. Mean transrectal ultrasound prostate volume was 99.3 gm (range 9 to 391). Mean preoperative American Urological Association symptom score was 20.3 (range 1 to 35) and maximum urinary flow was 8.4 cc per second (range 1.1 to 39.3). Intraoperative or postoperative complications occurred in 24 cases (2.3%). Mean followup was 287 days (range 6 to 3,571). At short-term, intermediate term and long-term followup the mean symptom score was 8.7, 5.9 and 5.3, and maximum urinary flow was 17.9, 19.5 and 22.7 cc per second, respectively. At the most recent followup 3 patients (0.3%) were in urinary retention. One patient with maximum urinary flow 20 cc per second required a second procedure for bleeding prostatic regrowth. Urethral stricture was noted in 9 (0.9%), 11 (1.3%), 4 (1.3%) and 0 patients, and bladder neck contracture was found in 0, 7 (0.8%), 4 (1.3%) and 5 (6.0%) at short-term, intermediate term, long-term and greater than 5-year followup, respectively. At the most recent followup significant stress and urge incontinence was noted in 9 and 6 patients, respectively. CONCLUSIONS: Holmium laser prostate enucleation is safe and effective for benign prostatic hyperplasia. The complication rate is low, and incontinence and the need for ancillary procedures are rare for holmium laser prostate enucleation with durable long-term results.

Extracorporeal shock wave lithotripsy treatment for calculi of the upper urinary tract was performed in 15 children between 3 and 17 years old. Success was achieved in 93 per cent of the cases (72 per cent were free of stone and 21 per cent had insignificant fragments). No major complications were encountered in the series.

OBJECTIVE: Helical CT has become the preferred methodology for identifying urinary calculi. However, the ability to predict stone composition, which influences patient treatment, depends on the accurate measurement of the radiographic attenuation of stones. We studied the effects of stone composition, stone size, and scan collimation width on the measurement of attenuation in vitro. MATERIALS AND METHODS: One hundred twenty-seven human urinary calculi of known composition and size were scanned at 120 kVp, 240 mA, and a 1:1 pitch at different collimations. A model, based on the physics of helical CT, was used to predict the effect of scan collimation width and stone size on measured attenuation. RESULTS: At a 1-mm collimation, stone groups could be differentiated by attenuation: the attenuation of uric acid was less than that of cystine or struvite, which overlapped; these were less than the attenuation of calcium oxalate monohydrate, which was in turn lower than that of brushite and hydroxyapatite, which overlapped and showed the highest values. At a wider collimation, attenuation was lower and the ability to differentiate stone composition was lost. Attenuation also decreased with smaller stones. At a 10-mm collimation, some uric acid stones (<approximately 6 mm) and other stones (< approximately 4 mm) had very low attenuation, so low that they could remain undetected on helical CT. The model predicted well the degree that attenuation was affected by stone size and collimation width. CONCLUSION: Stone composition and stone size, relative to CT collimation, independently influenced CT attenuation. The effect of stone size and collimation generally conformed to the model's predictions. We determined that small stones with low attenuation can be overlooked on helical CT.

Although calcium oxalate (CaOx) renal stones are known to grow attached to renal papillae, and specifically to regions of papillae that contain Randall's plaque (interstitial apatite deposits), the mechanisms of stone overgrowth on plaque are not known. To investigate the problem, we have obtained biopsy specimens from two stone patients that included an attached stone along with its tissue base and have studied the ultrastructural features of the attachment point using light and transmission electron microscopy, Fourier transform infrared spectroscopy (mu-FTIR), and immunohistochemical analysis. The epithelium is disrupted at the attachment site. The denuded plaque that borders on the urinary space attracts an envelope of ribbon-like laminates of crystal and organic matrix arising from urine ions and molecules. Into the matrix of this ribbon grow amorphous apatite crystals that merge with and give way to the usual small apatite crystals imbedded in stone matrix; eventually CaOx crystals admix with apatite and become the predominant solid phase. Over time, urine calcium and oxalate ions gradually overgrow on the large crystals forming the attached stone.

PURPOSE: Percutaneous nephrolithotomy has undergone considerable evolution since its introduction in the 1970s, which has been driven by advances in access techniques, instrumentation and endoscopic technology. Recent reports suggest an increase in the number of percutaneous stone treatments being performed. However, despite the increasing use of percutaneous nephrolithotomy a minority of urologists obtain their own access. We reviewed the techniques for performing safe and effective percutaneous renal access. MATERIALS AND METHODS: A literature search using Entrez PubMed was performed. All relevant literature concerning techniques for fluoroscopic percutaneous renal access published within the last 20 years was reviewed. RESULTS: The success of percutaneous nephrolithotomy is critically dependent on achieving suitable percutaneous access. The ideal site of percutaneous puncture should be selected to maximize the use of rigid instruments, minimize the risk of complications and attain stone-free status. Familiarity with basic renal anatomy is essential to obtain access safely. Adherence to basic principles allows the establishment of percutaneous access in a straightforward and efficient manner. Certain clinical situations may require special access techniques. CONCLUSIONS: Percutaneous nephrolithotomy is the treatment of choice for complex stone disease. While the efficacy of percutaneous nephrolithotomy relies on the establishment of effective percutaneous access, there are considerable advantages for the urologist able to achieve access.

Hypertension has been reported as a possible sequela of extracorporeal shock wave lithotripsy (ESWL). To evaluate this issue as well as the risk of hypertension following other current non-ESWL treatment options for urolithiasis (percutaneous nephrostolithotomy [PCNL], combined PCNL and ESWL, ureteroscopy, and spontaneous stone passage), detailed blood pressure measurements were made in 961 patients at least 1 year after treatment. All follow-up blood pressures were measured with random-zero blood pressure devices. This study includes 731 patients who received ESWL only (with an unmodified lithotriptor), 171 patients treated with ureteroscopy or spontaneous stone passage (control subjects), 25 patients who received PCNL only, and 34 patients treated with both ESWL and PCNL. In patients who received ESWL only, the annualized incidence of hypertension (2.4%) did not differ significantly from that in control patients (4.0%). Among patients who received ESWL, no correlation was found between the incidence of hypertension and unilateral vs bilateral treatments, the number of shock waves administered, the kilovoltage applied, or the power (number of shock waves times kilovoltage). However, there was a significant rise in diastolic blood pressure after treatment with ESWL (0.78 mm Hg), but not in the control group (-0.88 mm Hg). The long-term significance of this change in diastolic blood pressure following ESWL is unknown and requires further study.

PURPOSE OF REVIEW: Percutaneous nephrolithotomy has undergone an evolution in technique and in equipment since its introduction in the late 1970s. This evolution continues today and is evidenced by the numerous publications about the technique. This review summarizes some of the important articles over the past year. RECENT FINDINGS: Although ureteroscopy and shock wave lithotripsy predominate in the treatment of urolithiasis, percutaneous nephrolithotomy continues to play an important role. Percutaneous nephrolithotomy is advantageous as it causes minimal renal injury and maximizes stone clearance, especially in patients with complex stone disease. Although nephrostomy drainage tubes have always been placed after percutaneous nephrolithotomy, there may be specific indications for tubeless percutaneous nephrolithotomy. SUMMARY: Percutaneous nephrolithotomy continues to be an important part of the urologist's armamentarium. Recent studies have redefined the role of percutaneous nephrolithotomy and future studies will further delineate the importance of this procedure in the treatment of urolithiasis.

PURPOSE: Knowledge of the inciting lesion in kidney stone formation has remained rudimentary until quite recently. Randall theorized that areas of apatite plaque on the renal papillae would be an ideal site for an overgrowth of calcium oxalate to develop into a calculus. We reviewed in vivo data that have further defined the role of Randall's plaques in stone disease. MATERIALS AND METHODS: We examined a set of literature that tested 2 hypotheses, that is 1) Randall's plaques are a specialized disease that begins as apatite in a unique region of the kidney due to local driving forces and anatomy, and 2) stones that arise from causes different from common calcium oxalate stones do not necessarily arise on plaque. RESULTS: Intraoperative papillary and cortical biopsy specimens obtained during percutaneous nephrolithotomy from the kidneys of 3 types of stone formers (idiopathic calcium stone formers, patients with stones due to bariatric procedures and brushite stone formers) showed unique histopathological findings. CONCLUSIONS: The metabolic and surgical pathological findings in 3 distinct groups of stone formers demonstrate that the histology of the renal papillae from a stone former is particular to the clinical setting.

BACKGROUND AND PURPOSE: Renal colic in pregnancy presents a diagnostic and therapeutic challenge. When conservative therapy fails or is not indicated, temporary measures such as ureteral stenting are often chosen as a first-line intervention, postponing definitive management until after delivery. We propose that advances in endoscopic equipment and anesthesia techniques dictate a more definitive strategy. PATIENTS AND METHODS: A retrospective analysis was performed on 10 consecutive pregnant patients presenting with renal colic necessitating intervention between April 1998 and April 2000. The mean patient age was 23 (range 17-31) years. One patient presented during the first trimester, six in the second, and three in the third. Four of the patients had a history of stone disease. All patients had flank pain at presentation, six on the left side and four on the right. Hematuria, fever, and nausea were present in eight, one and two patients, respectively. RESULTS: Ultrasound scanning was performed in all patients and showed a low sensitivity (28.5%) when compared with intraoperative findings. Ureteroscopy (rigid and/or flexible) was performed as a first-line intervention in six patients, in two of whom no stone was found. Percutaneous nephrolithotomy was carried out in one patient presenting with a nephrostomy tube. Double-J stents were placed in only three patients with specific indications, namely urinary infection, late gestational phase, and difficult ureteroscopy secondary to a narrow ureter. No obstetric or urologic complications were noted. The mean size of the stones retrieved in seven patients was 7 mm. CONCLUSIONS: Ureteroscopy may be considered a safe and effective first-line definitive therapeutic option in pregnant patients requiring intervention for stone disease.

The optimal management of lower pole renal calculi is controversial. We compared shock wave lithotripsy (SWL) and ureteroscopy (URS) for the treatment of patients with small lower pole stones in a prospective, randomized, multicenter trial.A total of 78 patients with 1 cm or less isolated lower pole stones were randomized to SWL or URS. The primary outcome measure was stone-free rate on noncontrast computerized tomography at 3 months. Secondary outcome parameters were length of stay, complication rates, need for secondary procedures and patient derived quality of life measures.A total of 67 patients randomized to SWL (32) or URS (35) completed treatment. The 2 groups were comparable with respect to age, sex, body mass index, side treated and stone surface area. Operative time was significantly shorter for SWL than URS (66 vs 90 minutes). At 3 months of followup 26 and 32 patients who underwent SWL and URS had radiographic followup that demonstrated a stone-free rate of 35% and 50%, respectively (p not significant). Intraoperative complications occurred in 1 SWL case (unable to target stone) and in 7 URS cases (failed access in 5 and perforation in 2), while postoperative complications occurred in 7 SWL and 7 URS cases. Patient derived quality of life measures favored SWL.This study failed to demonstrate a statistically significant difference in stone-free rates between SWL and URS for the treatment of small lower pole renal calculi. However, SWL was associated with greater patient acceptance and shorter convalescence.

Lithotripsy shock waves (SW) to one renal pole damage that pole but protect the opposite pole from the damage inflicted by another, immediate application of SW. This study investigated whether the protection (1) occurs when the first treatment causes no injury, (2) is caused by SW or injury, (3) exhibits a threshold, and (4) occurs when the same pole receives both treatments. Six- to 7-wk-old anesthetized female pigs were studied. The following groups were studied: group 1 (n=4), 2000 SW at 12 kV to one pole and 2000 SW at 24 kV (standard) to the opposite pole; group 2 (n=6), same as group 1 except 500 12-kV SW pretreatment; group 3 (n=8), 500 12-kV, 2000 standard SW, all to the same pole; and group 4 (n=8), same as group 3 except 100 12-kV SW pretreatment. Mean+/-SD lesion size in group 1, first pole treated, was 0.66+/-0.82% of functional renal volume (FRV; P<0.05 versus 5.22+/-3.6% FRV with no pretreatment [NP]; 95% confidence interval [CI] -7.0 to -2.1) and 0.50+/-0.68% FRV in the opposite pole after 2000 standard SW (P<0.05 versus NP; 95% CI -9.4 to -0.08). Mean lesion size (first pole) in group 2 was 0.020+/-0.028% FRV (P<0.01 versus NP; 95% CI -9.2 to -1.2) and 0.43+/-0.54% FRV in the opposite pole after 2000 standard SW (P<0.05 versus NP; 95% CI -8.8 to -0.82). Same-pole SW (groups 3 and 4) also protected. Mean lesion sizes were 0.28+/-0.33% (P<0.01 versus NP; 95% CI -8.0 to -1.9) in group 3 and 0.39+/-0.48% FRV (P<0.01 versus NP; 95% CI -8.2 to -1.7) in group 4. It is concluded that the pretreatment protocol substantially limits the renal injury that normally is caused by SWL and occurs when the pretreatment and standard SW are applied to the same pole. The threshold for the protection may be <100 SW.

PURPOSE: We assessed the near term comfort of newly designed ureteral study stents or marketed control stents, including Polaris and Percuflex stents. Study stents had distal 6Fr pigtail ends with 3Fr or less loops. Decreased material in situ was hypothesized to enhance comfort. Usefulness of the patient self-administered Ureteral Stent Symptoms Questionnaire (Stone Management Unit, Southmead Hospital, United Kingdom) was assessed. MATERIALS AND METHODS: This 4-arm multicenter study enrolled adults requiring retrograde unilateral ureteral stent placement for 4 to 28 days. Ureteral Stent Symptoms Questionnaire administration was done before placement (baseline), on day 4 after placement and on day 30 after removal. A total of 236 patients were randomized in a 1:1:1:1 ratio to the short loop tail stent (60), the long loop tail stent (59), the Percuflex Plus stent (64) and the Polaris stent (53). RESULTS: Overall pain worsened from baseline to day 4 and improved from days 4 to 30. Mean pain medication use peaked for all stents on day 1 after placement. Common device related symptoms were mild or moderate in severity, including flank pain in 47 patients, hematuria in 39, dysuria in 34, frequent urination in 30 and urinary urgency in 27. Six patients experienced a total of 9 device related adverse events requiring hospitalization. All adverse events resolved, including most within 3 days of inpatient treatment. CONCLUSIONS: Although it was not statistically significant, patients stented with the short loop tail had lower questionnaire pain scores on day 4 after placement and lower pain medication use on day 1 after placement when pain peaked in all stent groups, suggesting that ureteral stent comfort, especially pain, may be improved by less material in situ. The Ureteral Stent Symptoms Questionnaire may be better suited for longer term comparisons in stented vs nonstented patients, rather than in this short-term ureteral stent trial.

OBJECTIVE: To assess the tissue protection afforded by simply reducing the rate of shock wave (SW) delivery, compared with studies in the pig in which SW lithotripsy (SWL)-induced vascular damage was significantly reduced by initiating treatment using low-amplitude SWs. MATERIALS AND METHODS: Juvenile pigs (6-7 weeks old) were treated with an unmodified lithotripter (HM3, Dornier Medical Systems, Kennesaw, GA) at either 120 or 30 SW/min. Treatment was to one kidney per pig, with SWs (2000, 24 kV) directed to a lower-pole calyx. After treatment, parenchymal haemorrhage was determined morphometrically and expressed as percentage of functional renal volume (%FRV). RESULTS: Kidneys treated at 120 SW/min had focal to extensive subcapsular haematomas. Parenchymal lesions were found only at the lower pole, but included regions within renal papillae and the cortex. Occasionally, damage extended across the full thickness of the kidney. The lesion in the pigs treated at 120 SW/min occupied a mean (sd) of 4.6 (1.7) %FRV. Kidneys of pigs treated at 30 SW/min showed no surface bleeding. Parenchymal haemorrhage was limited to papillae within the focal volume, and measured 0.08 (0.02) %FRV, a significant (P < 0.005) reduction in injury. CONCLUSIONS: Slowing the rate of delivery to 30 SW/min has a dramatic protective effect on the integrity of the kidney vasculature. This finding in our established pig model suggests a potential strategy to improve the safety of lithotripsy. As it was shown that a reduced SW rate also improves the efficiency of stone fragmentation, a slow rate appears to be a means to improve both the safety and efficacy of SWL.

BACKGROUND AND PURPOSE: Open simple prostatectomy has been considered the treatment of choice for symptomatic benign prostatic hyperplasia (BPH) of large prostates because traditional endoscopic techniques have not proven either effective or feasible. We present our experience with holmium laser enucleation of the prostate (HoLEP) for glands >175 cc. METHODS: An Institutional Review Board approved prospective database has been maintained since January 1999 for all HoLEP procedures. The database was reviewed retrospectively for patients who underwent HoLEP for BPH with a preoperative transrectal ultrasonography (TRUS) volume of >175 cc. RESULTS: From January 1999 to November 2008, we identified 57 patients with a mean pretreatment TRUS volume of 217.8 cc (range 175-391 cc). Preoperative retention was present in 30 patients. Preoperative mean prostate-specific antigen level was 14.6 ng/mL, mean American Urological Association (AUA) symptom index was 19.0, and mean peak flow (Qmax) was 8.2 mL/sec. Mean hospital stay was 26 hours, and postoperative catheterization was 18.5 hours (range 6-96 hrs). All patients were able to void after catheter removal. Mean enucleated tissue weight was 176.4 g (range 48-532.2 g). At 6-month follow-up, AUA symptom index was 6.5, mean PSA level was 0.78 ng/mL, and Qmax was 18.5. During the follow-up period, no patient needed catheterization or had persistent incontinence. CONCLUSIONS: Even in the large prostate gland, HoLEP provides a satisfactory outcome with low morbidity. HoLEP is the only endoscopic technique that allows for tissue removal comparable to that of open prostatectomy for such patients.

No AccessJournal of UrologyVoiding Dysfunction1 Jan 2013Experience With More Than 1,000 Holmium Laser Prostate Enucleations for Benign Prostatic Hyperplasiais accompanied byExperience With More Than 1,000 Holmium Laser Prostate Enucleations for Benign Prostatic Hyperplasia Amy E. Krambeck, Shelly E. Handa, and James E. Lingeman Amy E. KrambeckAmy E. Krambeck More articles by this author , Shelly E. HandaShelly E. Handa More articles by this author , and James E. LingemanJames E. Lingeman More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.11.027AboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract Purpose: Holmium laser prostate enucleation is a contemporary treatment for benign prostatic hyperplasia. We report our experience with more than 1,000 procedures. Materials and Methods: From June 1998 to March 2009 we performed 1,065 holmium laser prostate enucleations. After receiving institutional review board approval we retrospectively reviewed the database. Reported short-term, intermediate term and long-term results are 0 to 6, 6 to 12 and greater than 12 months, respectively. Results: Bladder stones were present in 50 patients (4.7%) and 87 of the 717 (12.1%) with laboratory studies available had renal insufficiency. Preoperative urinary retention was present in 411 cases (38.7%). Significant preoperative stress and urge incontinence was noted in 8 and 16 patients, respectively. Mean transrectal ultrasound prostate volume was 99.3 gm (range 9 to 391). Mean preoperative American Urological Association symptom score was 20.3 (range 1 to 35) and maximum urinary flow was 8.4 cc per second (range 1.1 to 39.3). Intraoperative or postoperative complications occurred in 24 cases (2.3%). Mean followup was 287 days (range 6 to 3,571). At short-term, intermediate term and long-term followup the mean symptom score was 8.7, 5.9 and 5.3, and maximum urinary flow was 17.9, 19.5 and 22.7 cc per second, respectively. At the most recent followup 3 patients (0.3%) were in urinary retention. One patient with maximum urinary flow 20 cc per second required a second procedure for bleeding prostatic regrowth. Urethral stricture was noted in 9 (0.9%), 11 (1.3%), 4 (1.3%) and 0 patients, and bladder neck contracture was found in 0, 7 (0.8%), 4 (1.3%) and 5 (6.0%) at short-term, intermediate term, long-term and greater than 5-year followup, respectively. At the most recent followup significant stress and urge incontinence was noted in 9 and 6 patients, respectively. Conclusions: Holmium laser prostate enucleation is safe and effective for benign prostatic hyperplasia. The complication rate is low, and incontinence and the need for ancillary procedures are rare for holmium laser prostate enucleation with durable long-term results. References 1 : A systematic review of holmium laser prostatectomy for benign prostatic hyperplasia. J Urol2004; 171: 1773. Link, Google Scholar 2 : Transurethral holmium laser enucleation versus transvesical open enucleation for prostate adenoma greater than 100 gm: a randomized prospective trial of 120 patients. J Urol1465; 168: 1465. Google Scholar 3 : Holmium laser treatment of benign prostatic hyperplasia: an update. Curr Opin Urol2007; 17: 27. Google Scholar 4 : Transurethral holmium laser enucleation of the prostate versus transurethral electrocautery resection of the prostate: a randomized prospective trial in 200 patients. J Urol2004; 172: 1012. Link, Google Scholar 5 : Holmium laser enucleation versus transurethral resection of the prostate: 3-year follow-up results of a randomized clinical trial. Eur Urol2007; 52: 1456. Google Scholar 6 : Holmium laser enucleation versus transurethral resection of the prostate: results from a 2-center, prospective, randomized trial in patients with benign prostatic hyperplasia. J Urol2004; 172: 1926. Google Scholar 7 : Holmium laser versus transurethral resection of the prostate: a randomized prospective trial with 1 year follow-up. J Urol1999; 162: 1640. Link, Google Scholar 8 : A randomized trial comparing holmium laser enucleation versus transurethral resection in the treatment of prostates larger than 40 grams: results at 2 years. Eur Urol2006; 50: 569. Google Scholar 9 : Holmium laser enucleation of the prostate: results at 6 years. Eur Urol2008; 53: 744. Google Scholar 10 : Holmium laser enucleation of the prostate (HoLEP): the Methodist hospital experience with greater than 75 gram enucleations. J Urol2003; 170: 149. Link, Google Scholar 11 : Holmium laser enucleation of the prostate: a size-independent new “gold standard”. Urology2005; 66: 108. Google Scholar 12 : Holmium laser enucleation of the prostate (HoLEP): the endourologic alternative to open prostatectomy. Eur Urol2006; 49: 87. Google Scholar 13 : Holmium laser enucleation of the prostate versus open prostatectomy for prostates greater than 100 grams: 5-year follow-up results of a randomized clinical trial. Eur Urol2008; 53: 160. Google Scholar 14 : Holmium laser enucleation of the prostate in patients on anticoagulant therapy or with bleeding disorders. J Urol2006; 175: 1428. Link, Google Scholar 15 : Holmium laser enucleation of the prostate (HoLEP): long-term results, reoperation rate, and possible impact of the learning curve. Eur Urol2007; 52: 1465. Google Scholar 16 : Holmium laser resection of the prostate is more cost effective than transurethral resection of the prostate: results of a randomized prospective study. Urology2001; 57: 454. Google Scholar 17 : Systematic review and economic modeling of effectiveness and cost utility of surgical treatments for men with benign prostatic enlargement. Health Technol Assess2008; 12: 169. Google Scholar 18 : Holmium laser enucleation of the prostate (HoLEP): a technical update. World J Surg Oncol2003; 1: 6. Google Scholar 19 : Current techniques for laser prostatectomy—PVP and HoLEP. Arch Esp Urol2008; 61: 1005. Google Scholar 20 : Photoselective potassium-titanyl-phosphate laser vaporization of the benign obstructive prostate: observations on long-term outcomes. J Urol2005; 174: 1344. Link, Google Scholar Methodist Hospital Institute for Kidney Stone Disease, Indianapolis, Indiana© 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetailsCited byLee M, Assmus M, Agarwal D, Large T and Krambeck A (2021) A Cost Comparison of Holmium Laser Enucleation of the Prostate with and without Moses™Urology Practice, VOL. 8, NO. 6, (624-629), Online publication date: 1-Nov-2021.Kaplan S (2020) Re: Holmium Laser Enucleation of the Prostate in Benign Prostate Hyperplasia Patients with or without Oral Antithrombotic Drugs: A Meta-AnalysisJournal of Urology, VOL. 204, NO. 5, (1070-1070), Online publication date: 1-Nov-2020.Johnsen N, Kammann T, Marien T, Pickens R and Miller N (2015) Comparison of Holmium Laser Prostate Enucleation Outcomes in Patients with or without Preoperative Urinary RetentionJournal of Urology, VOL. 195, NO. 4 Part 1, (1021-1026), Online publication date: 1-Apr-2016.Large T, Borofsky M and Lingeman J (2015) Re: Photoselective Vaporization of the Prostate for Benign Prostatic Hyperplasia Using the 180 Watt System: Multicenter Study of the Impact of Prostate Size on Safety and Outcomes and Re: GreenLight™ Laser (XPS) Photoselective Vapo-Enucleation versus Holmium Laser Enucleation of the Prostate for the Treatment of Symptomatic Benign Prostatic Hyperplasia: A Randomized Controlled StudyJournal of Urology, VOL. 195, NO. 1, (228-231), Online publication date: 1-Jan-2016.Related articlesJournal of Urology21 Jan 2010Experience With More Than 1,000 Holmium Laser Prostate Enucleations for Benign Prostatic Hyperplasia Volume 189Issue 1SJanuary 2013Page: S141-S145 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.Keywordslaser therapytransurethral resection of prostateprostatic hyperplasiaprostateprostatectomyMetricsAuthor Information Amy E. 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PURPOSE: It has been proposed that calcium oxalate calculi begin as small stones attached to the renal papillae at sites of Randall's plaque. However, no study has investigated the prevalence of attached stones in calcium oxalate stone formers or the relationship between stone attachment site and Randall's plaque. In this study we used endoscopic examination of renal papillae in stone formers undergoing percutaneous nephrolithotomy to investigate both issues. MATERIALS AND METHODS: Idiopathic calcium oxalate stone formers undergoing PNL for stone removal were enrolled in this study. Multiple papillae were examined and images were recorded by digital video. The presence or absence of papillary plaque and attached stones was noted, as was the site of stone attachment. RESULTS: In 23 patients, 24 kidneys and 172 renal papillae were examined. All kidneys were found to have papillary plaque and 11 of the patients had attached stones. Most papillae (91%) contained plaque. CONCLUSIONS: The prevalence of attached stones in calcium oxalate stone formers (48%) is greater than that previously reported for the general population. Attachment appears to be on Randall's plaque. The high prevalence of attached stones and the appearance of the attachment site are consistent with a mechanism of calcium oxalate stone formation in which stones begin as plaque overgrowth.

BACKGROUND AND PURPOSE: Shockwave lithotripsy (SWL) predictably damages renal tissue and transiently reduces function in both kidneys. This study characterized the effects on renal function of a supraclinical dose of shockwaves (SWs) (8000) in porcine kidneys and tested the hypothesis that such excessive treatment would intensify and prolong the resulting renal impairment. MATERIALS AND METHODS: Pigs aged 6 to 7 weeks were anesthetized and assigned to one of three groups. Groups 1 (N=8) and 2 (N=6) each received 8000 SWs at 24 kV (Dornier HM3) to the lower-pole calix of one kidney. Group 3 (7 pigs) received sham treatment. Renal function was monitored for the first 4 hours after SW treatment in Group 1 and for 24 hours in Group 2. Plasma renin activity was measured in Groups 2 and 3. RESULTS: The renal lesions produced by 8000 SWs comprised 13.8%+/-1.4% of the renal mass. In the 4-hour protocol, this injury was associated with marked reduction of the glomerular filtration rate (GFR), renal plasma flow (RPF), and urinary sodium excretion in both kidneys, although fractional sodium excretion was reduced only in the shocked kidneys. In the 24-hour protocol, GFR and RPF remained below baseline in shocked kidneys at 24 hours. Evidence of progressive ischemic injury was noted in shocked tissue at 24 hours after SW treatment. CONCLUSIONS: These findings support the hypothesis that the severity of the renal injury caused by SWL is related to the number of SWs administered and demonstrate the connection in this relation between renal structure and function.

PURPOSE: We evaluated the short-term safety and efficacy of a ketorolac loaded ureteral stent compared to a standard stent (control). MATERIALS AND METHODS: In this prospective, multicenter, double-blind study patients were randomized 1:1 to ketorolac loaded or control stents after ureteroscopy. The primary end point was an intervention for pain defined as unscheduled physician contact, change in pain medication or early stent removal. Secondary end points included medication use and pain visual analog score. A total of 20 patients underwent serum safety testing for ketorolac levels. RESULTS: None of the safety cohort had detectable serum ketorolac levels. Among the 276 patients there was no difference in primary (9.0% ketorolac loaded vs 7.0% control, p = 0.66) or secondary (22.6% ketorolac loaded vs 25.2% control, p = 0.67) intervention rates. Mean pain pill count at day 3 was lower in the ketorolac loaded stent group than in the control group (p <0.05). A higher number (p = 0.057) of patients with ketorolac loaded (32%) stents used no or limited pain medications compared to controls (22%). A higher number of male patients with ketorolac loaded stents used no pain medication on days 3 and 4 compared to female patients with ketorolac loaded stents, and male and female control patients (p <0.05). CONCLUSIONS: The overall safety of the ketorolac loaded stent was confirmed. Although there was no significant difference in primary or secondary intervention rates, a trend toward a treatment benefit was noted for patients receiving drug loaded stents. Specifically young male patients appeared to require less pain medication when the ketorolac loaded stent was used. Future studies with higher drug concentrations or alternative drug eluting stents may prove beneficial.