Cost-utility analysis of shockwave lithotripsy vs ureteroscopic stone treatment in adults.

OBJECTIVES: To assess the cost-effectiveness, resource use implications, quality-adjusted life-years (QALYs) and cost per QALY of care pathways starting with either extracorporeal shockwave lithotripsy (SWL) or with ureteroscopic retrieval (ureteroscopy [URS]) for the management of ureteric stones. PATIENTS AND METHODS: Data on quality of life and resource use for 613 patients, collected prospectively in the Therapeutic Interventions for Stones of the Ureter (TISU) randomized controlled trial (ISRCTN 92289221), were used to assess the cost-effectiveness of two care pathways, SWL and URS. A health provider (UK National Health Service) perspective was adopted to estimate the costs of the interventions and subsequent resource use. Quality-of-life data were calculated using a generic instrument, the EuroQol EQ-5D-3L. Results are expressed as incremental cost-effectiveness ratios and cost-effectiveness acceptability curves. RESULTS: The mean QALY difference (SWL vs URS) was -0.021 (95% confidence interval [CI] -0.033 to -0.010) and the mean cost difference was -£809 (95% CI -£1061 to -£551). The QALY difference translated into approximately 10 more healthy days over the 6-month period for the patients on the URS care pathway. The probabaility that SWL is cost-effective is 79% at a society's willingness to pay (WTP) threshold for 1 QALY of £30,000 and 98% at a WTP threshold of £20,000. CONCLUSION: The SWL pathway results in lower QALYs than URS but costs less. The incremental cost per QALY is £39 118 cost saving per QALY lost, with a 79% probability that SWL would be considered cost-effective at a WTP threshold for 1 QALY of £30 000 and 98% at a WTP threshold of £20 000. Decision-makers need to determine if costs saved justify the loss in QALYs.

Shockwave lithotripsy compared with ureteroscopic stone treatment for adults with ureteric stones: the TISU non-inferiority RCT.

BACKGROUND: Urinary stone disease affects 2-3% of the general population. Ureteric stones are associated with severe pain and can have a significant impact on a patient's quality of life. Most ureteric stones are expected to pass spontaneously with supportive care; however, between one-fifth and one-third of patients require an active intervention. The two standard interventions are shockwave lithotripsy and ureteroscopic stone treatment. Both treatments are effective, but they differ in terms of invasiveness, anaesthetic requirement, treatment setting, number of procedures, complications, patient-reported outcomes and cost. There is uncertainty around which is the more clinically effective and cost-effective treatment. OBJECTIVES: To determine if shockwave lithotripsy is clinically effective and cost-effective compared with ureteroscopic stone treatment in adults with ureteric stones who are judged to require active intervention. DESIGN: A pragmatic, multicentre, non-inferiority, randomised controlled trial of shockwave lithotripsy as a first-line treatment option compared with primary ureteroscopic stone treatment for ureteric stones. SETTING: Urology departments in 25 NHS hospitals in the UK. PARTICIPANTS: Adults aged ≥ 16 years presenting with a single ureteric stone in any segment of the ureter, confirmed by computerised tomography, who were able to undergo either shockwave lithotripsy or ureteroscopic stone treatment and to complete trial procedures. INTERVENTION: Eligible participants were randomised 1 : 1 to shockwave lithotripsy (up to two sessions) or ureteroscopic stone treatment. MAIN OUTCOME MEASURES: The primary clinical outcome measure was resolution of the stone episode (stone clearance), which was operationally defined as 'no further intervention required to facilitate stone clearance' up to 6 months from randomisation. This was determined from 8-week and 6-month case report forms and any additional hospital visit case report form that was completed by research staff. The primary economic outcome measure was the incremental cost per quality-adjusted life-year gained at 6 months from randomisation. We estimated costs from NHS resources and calculated quality-adjusted life-years from participant completion of the EuroQol-5 Dimensions, three-level version, at baseline, pre intervention, 1 week post intervention and 8 weeks and 6 months post randomisation. RESULTS: In the shockwave lithotripsy arm, 67 out of 302 (22.2%) participants needed further treatment. In the ureteroscopic stone treatment arm, 31 out of 302 (10.3%) participants needed further treatment. The absolute risk difference was 11.4% (95% confidence interval 5.0% to 17.8%); the upper bound of the 95% confidence interval ruled out the prespecified margin of non-inferiority (which was 20%). The mean quality-adjusted life-year difference (shockwave lithotripsy vs. ureteroscopic stone treatment) was -0.021 (95% confidence interval 0.033 to -0.010) and the mean cost difference was -£809 (95% confidence interval -£1061 to -£551). The probability that shockwave lithotripsy is cost-effective is 79% at a threshold of society's willingness to pay for a quality-adjusted life-year of £30,000. The CEAC is derived from the joint distribution of incremental costs and incremental effects. Most of the results fall in the south-west quadrant of the cost effectiveness plane as SWL always costs less but is less effective. LIMITATIONS: A limitation of the trial was low return and completion rates of patient questionnaires. The study was initially powered for 500 patients in each arm; however, the total number of patients recruited was only 307 and 306 patients in the ureteroscopic stone treatment and shockwave lithotripsy arms, respectively. CONCLUSIONS: Patients receiving shockwave lithotripsy needed more further interventions than those receiving primary ureteroscopic retrieval, although the overall costs for those receiving the shockwave treatment were lower. The absolute risk difference between the two clinical pathways (11.4%) was lower than expected and at a level that is acceptable to clinicians and patients. The shockwave lithotripsy pathway is more cost-effective in an NHS setting, but results in lower quality of life. FUTURE WORK: (1) The generic health-related quality-of-life tools used in this study do not fully capture the impact of the various treatment pathways on patients. A condition-specific health-related quality-of-life tool should be developed. (2) Reporting of ureteric stone trials would benefit from agreement on a core outcome set that would ensure that future trials are easier to compare. TRIAL REGISTRATION: This trial is registered as ISRCTN92289221. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 19. See the NIHR Journals Library website for further project information.

Approximately 1 in 20 people suffers from kidney stones that pass down the urine drainage tube (ureter) into the urinary bladder and cause episodes of severe pain (ureteric colic). People with ureteric colic attend hospital for pain relief and diagnosis. Although most stones smaller than 10 mm eventually reach the bladder and are passed during urination, some get stuck and have to be removed using telescopic surgery (called ureteroscopic stone treatment) or shockwave therapy (called shockwave lithotripsy). Ureteroscopic stone treatment involves passing a telescope-containing instrument through the bladder and into the ureter to fragment and/or remove the stone. This is usually carried out under general anaesthetic as a day case. For shockwave lithotripsy, the patient lies flat on a couch and the apparatus underneath them generates shockwaves that pass through the skin to the ureter and break the stones into smaller fragments, which can be passed naturally in the urine. This involves using X-ray or ultrasound to locate the stone, but can be carried out on an outpatient basis and without general anaesthetic. Telescopic surgery is known to be more successful at removing stones after just one treatment, but it requires more time in hospital and has a higher risk of complications than shockwave lithotripsy (however, shockwave lithotripsy may require more than one session of treatment). Our study, the Therapeutic Interventions for Stones of the Ureter trial, was designed to establish if treatment for ureteric colic should start with telescopic surgery or shockwave therapy. Over 600 NHS patients took part and they were split into two groups. Each patient had an equal chance of their treatment starting with either telescopic surgery or shockwave lithotripsy, which was decided by a computer program (via random allocation). We counted how many patients in each group had further procedures to remove their stone. We found that telescopic surgery was 11% more effective overall, with an associated slightly better quality of life (10 more healthy days over the 6-month period), but was more expensive in an NHS setting. The finding of a lack of any significant additional clinical benefit leads to the conclusion that the more cost-effective treatment pathway is shockwave lithotripsy with telescopic surgery used only in those patients in whom shockwave lithotripsy is unsuccessful.

Shockwave Lithotripsy Versus Ureteroscopic Treatment as Therapeutic Interventions for Stones of the Ureter (TISU): A Multicentre Randomised Controlled Non-inferiority Trial.

BACKGROUND: Renal stone disease is common and can cause emergency presentation with acute pain due to ureteric colic. International guidelines have stated the need for a multicentre randomised controlled trial (RCT) to determine whether a non-invasive outpatient (shockwave lithotripsy [SWL]) or surgical (ureteroscopy [URS]) intervention should be the first-line treatment for those needing active intervention. This has implications for shaping clinical pathways. OBJECTIVE: To report a pragmatic multicentre non-inferiority RCT comparing SWL with URS. DESIGN, SETTING, AND PARTICIPANTS: This trial tested for non-inferiority of up to two sessions of SWL compared with URS as initial treatment for ureteric stones requiring intervention. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome was whether further intervention was required to clear the stone, and secondary outcomes included quality of life assessment, severity of pain, and serious complications; these were based on questionnaires at baseline, 8 wk, and 6 mo. We included patients over 16 yr with a single ureteric stone clinically deemed to require intervention. Intention-to-treat and per-protocol analyses were planned. RESULTS AND LIMITATIONS: The study recruited between July 1, 2013 and June 30, 2017. We recruited 613 participants from a total of 1291 eligible patients, randomising 306 to SWL and 307 to URS. Sixty-seven patients (22.1%) in the SWL arm needed further treatment compared with 31 patients (10.3%) in the URS arm. The absolute risk difference was 11.7% (95% confidence interval 5.6%, 17.8%) in favour of URS, which was inside the 20% threshold we set for demonstrating noninferiority of SWL. CONCLUSIONS: This RCT was designed to test whether SWL is non-inferior to URS and confirmed this; although SWL is an outpatient noninvasive treatment with potential advantages both for patients and for reducing the use of inpatient health care resources, the trial showed a benefit in overall clinical outcomes with URS compared with SWL, reflecting contemporary practice. The Therapeutic Interventions for Stones of the Ureter (TISU) study provides new evidence to help guide the choice of modality for this common health condition. PATIENT SUMMARY: We present the largest trial comparing ureteroscopy versus extracorporeal shockwave lithotripsy for ureteric stones. While ureteroscopy had marginally improved outcome in terms of stone clearance, as expected, shockwave lithotripsy had better results in terms of health care costs. These results should enable patients and health care providers to optimise treatment pathways for this common urological condition.

The clinical and cost effectiveness of surgical interventions for stones in the lower pole of the kidney: the percutaneous nephrolithotomy, flexible ureterorenoscopy and extracorporeal shockwave lithotripsy for lower pole kidney stones randomised controlled trial (PUrE RCT) protocol.

INTRODUCTION: Renal stones are common, with a lifetime prevalence of 10% in adults. Global incidence is increasing due to increases in obesity and diabetes, with these patient populations being more likely to suffer renal stone disease. Flank pain from stones (renal colic) is the most common cause of emergency admission to UK urology departments. Stones most commonly develop in the lower pole of the kidney (in ~35% of cases) and here are least likely to pass without intervention. Currently there are three technologies available within the UK National Health Service to remove lower pole kidney stones: extracorporeal shockwave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL) and flexible ureterorenoscopy (FURS) with laser lithotripsy. Current evidence indicates there is uncertainty regarding the management of lower pole stones, and each treatment has advantages and disadvantages. The aim of this trial is to determine the clinical and cost effectiveness of FURS compared with ESWL or PCNL in the treatment of lower pole kidney stones. METHODS: The PUrE (PCNL, FURS and ESWL for lower pole kidney stones) trial is a multi-centre, randomised controlled trial (RCT) evaluating FURS versus ESWL or PCNL for lower pole kidney stones. Patients aged ≥16 years with a stone(s) in the lower pole of either kidney confirmed by non-contrast computed tomography of the kidney, ureter and bladder (CTKUB) and requiring treatment for a stone ≤10 mm will be randomised to receive FURS or ESWL (RCT1), and those requiring treatment for a stone >10 mm to ≤25 mm will be randomised to receive FURS or PCNL (RCT2). Participants will undergo follow-up by questionnaires every week up to 12 weeks post-intervention and at 12 months post-randomisation. The primary clinical outcome is health status measured by the area under the curve calculated from multiple measurements of the EuroQol five dimensions five-level version (EQ-5D-5L) questionnaire up to 12 weeks post-intervention. The primary economic outcome is the incremental cost per quality-adjusted life year gained at 12 months post-randomisation. DISCUSSION: The PUrE trial aims to provide robust evidence on health status, quality of life, clinical outcomes and resource use to directly inform choice and National Health Service provision of the three treatment options. TRIAL REGISTRATION: ISRCTN: ISRCTN98970319. Registered on 11 November 2015.

TISU: Extracorporeal shockwave lithotripsy, as first treatment option, compared with direct progression to ureteroscopic treatment, for ureteric stones: study protocol for a randomised controlled trial.

BACKGROUND: Urinary stone disease is very common with an estimated prevalence among the general population of 2-3%. Ureteric stones are associated with severe pain as they pass through the urinary tract and have significant impact on patients' quality of life due to the detrimental effect on their ability to work and need for hospitalisation. Most ureteric stones can be expected to pass spontaneously with supportive care. However, between one-fifth and one-third of cases require an intervention. The two standard active intervention options are extracorporeal shockwave lithotripsy (ESWL) and ureteroscopic stone retrieval. ESWL and ureteroscopy are effective in terms of stone clearance; however, they differ in terms of invasiveness, anaesthetic requirement, treatment setting, complications, patient-reported outcomes (e.g. pain after intervention, time off work) and cost. There is uncertainty around which is the most clinically effective in terms of stone clearance and the true cost to the NHS and to society (in terms of impact on patient-reported health and economic burden). The aim of this trial is to determine whether, in adults with ureteric stones, judged to require active intervention, ESWL is not inferior and is more cost-effective compared to ureteroscopic treatment as the initial management option. METHODS: The TISU study is a pragmatic multicentre non-inferiority randomised controlled trial of ESWL as the first treatment option compared with direct progression to ureteroscopic treatment for ureteric stones. Patients aged over 16 years with a ureteric stone confirmed by non-contrast computed tomography of the kidney, ureter and bladder (CTKUB) will be randomised to either ESWL or ureteroscopy. The primary clinical outcome is resolution of the stone episode (no further intervention required to facilitate stone clearance) up to six months from randomisation. The primary economic outcome is the incremental cost per quality-adjusted life years (QALYs) gained at six months from randomisation. DISCUSSION: Determining whether ESWL is not inferior clinically and is cost-effective compared to ureteroscopic treatment as the initial management in adults with ureteric stones who are judged to require active treatment is relevant not only to patients and clinicians but also to healthcare providers, both in the UK and globally. TRIAL REGISTRATION: ISRCTN registry, ISRCTN92289221 . Registered on 21 February 2013.

Update of the ICUD-SIU consultation on stone technology behind ureteroscopy.

INTRODUCTION: Ureteroscopy is now the most frequent treatment used around the world for stone disease. Technological advancement, efficiency, safety, and minimally invasiveness of this procedure are some of the reasons for this change of trend. MATERIALS AND METHODS: In this review of the literature, a search of the PubMed database was conducted to identify articles related to ureteroscopy and accessories. The committee assigned by the International Consultation on Urological Disease reviewed all the data and produced a consensus statement relating to the ureteroscopy and all the particularities around this procedure. CONCLUSION: This manuscript provides literatures and recommendations for endourologists to keep them informed in regard to the preoperative, intraoperative, and postoperative consideration in regard of a ureteroscopy.

The Role of Tandem Double-J Ureteral Stents in the Management of Malignant Ureteral Obstruction.

AIM: The management of malignant ureteral obstruction (MUO) is a challenging but common problem for urologists. The different techniques currently used to address this complicated issue include percutaneous nephrostomy, extra-anatomical stents, retrograde (single) stent insertion, and metallic stents. In those situations where single ureteral stent insertion has failed, retrograde tandem or twin ureteral stent (TUS) insertion can be completed. The aim of this study was to report our clinical experience and also assess the efficacy of TUS insertion within our tertiary referral center. METHODS: Data were prospectively collected from patients requiring TUSs over an 8-year period between January 1, 2006, and December 31, 2014. A number of variables, including the improvement in renal function following TUS insertion, were recorded. RESULTS: Twenty-two TUS insertion procedures were performed on 15 patients between the period of January 1, 2006, and December 31, 2014. The mean patient age was 68.0 years (39-85 years). There were 15 primary insertions as well as 7 subsequent stent changes. The average prenephrostomy creatinine was 428 µmol/L; an average improvement of 196 µmol/L was observed after percutaneous drainage. Serum creatinine after TUS remained stable on discharge, 214 µmol/L vs 227 µmol/L preoperatively, p = 0.34. Eleven patients died at a median 131 days post-TUS insertion. TUS failure occurred in three patients; this was characterized by rising creatinine and worsening hydronephrosis. Patients with failing TUS had a median life expectancy of 45.6 days compared with 162.5 days for those with functioning TUS (p < 0.05). Overall, the patency rate at 3 months was 80%. CONCLUSION: TUS insertion is a technically efficient and effective procedure in the management of MUO, with the majority of patients treated dying of the underlying condition with functioning stents in situ.

Use of drug therapy in the management of symptomatic ureteric stones in hospitalized adults (SUSPEND), a multicentre, placebo-controlled, randomized trial of a calcium-channel blocker (nifedipine) and an α-blocker (tamsulosin): study protocol for a randomized controlled trial.

BACKGROUND: Urinary stone disease is common, with an estimated prevalence among the general population of 2% to 3%. Ureteric stones can cause severe pain and have a significant impact on quality of life, accounting for over 15,000 hospital admissions in England annually. Uncomplicated cases of smaller stones in the lower ureter are traditionally treated expectantly. Those who fail standard care or develop complications undergo active treatment, such as extracorporeal shock wave lithotripsy or ureteroscopy with stone retrieval. Such interventions are expensive, require urological expertise and carry a risk of complications.Growing understanding of ureteric function and pathophysiology has led to the hypothesis that drugs causing relaxation of ureteric smooth muscle, such as the selective α-blocker tamsulosin and the calcium-channel blocker nifedipine, can enhance the spontaneous passage of ureteric stones. The use of drugs in augmenting stone passage, reducing the morbidity and costs associated with ureteric stone disease, is promising. However, the majority of clinical trials conducted to date have been small, poor to moderate quality and lacking in comprehensive economic evaluation.This trial aims to determine the clinical and cost-effectiveness of tamsulosin and nifedipine in the management of symptomatic urinary stones. METHODS/DESIGN: The SUSPEND (Spontaneous Urinary Stone Passage ENabled by Drugs) trial is a multicentre, double-blind, randomized controlled trial evaluating two medical expulsive therapy strategies (nifedipine or tamsulosin) versus placebo.Patients aged 18 to 65 with a ureteric stone confirmed by non-contrast computed tomography of the kidney, ureter and bladder will be randomized to receive nifedipine, tamsulosin or placebo (400 participants per arm) for a maximum of 28 days. The primary clinical outcome is spontaneous passage of ureteric stones at 4 weeks (defined as no further intervention required to facilitate stone passage). The primary economic outcome is a reduction in the incremental cost per quality-adjusted life years, determined at 12 weeks. The analysis will be based on all participants as randomized (intention to treat). The trial has 90% power with a type I error rate of 5% to detect a 10% increase in primary outcome between the tamsulosin and nifedipine treatment groups. TRIAL REGISTRATION: ISRCTN69423238; EudraCT number: 2010-019469-26.

Impact of imaging in urolithiasis treatment planning.

PURPOSE OF REVIEW: Over the past 10 years, we have seen major advances in urological imaging including developments in digital imaging, ultrasound and computerized tomography (CT) scanning. All of these have had an impact on the management of urinary tract stone disease. In parallel with these, we have witnessed a greater appreciation of the potential harm of irradiation exposure. In this article, we aim to provide an overview of the impact of imaging in urolithiasis treatment planning in 2013. RECENT FINDINGS: A variety of imaging modalities are reviewed with a focus on the latest research and developments. Advances do not always improve quality, and the deterioration in digital KUB sensitivity is discussed. The role of ultrasonography in the diagnosis and follow-up of stone disease is explored as a clinically valuable alternative to ionizing radiation. The explosion of interest in cross-sectional imaging for urolithiasis (extending from the evaluation of loin pain, characterization of stone composition through to complex three-dimensional reconstructions of the pelvicalyceal system for surgical planning) is reviewed. SUMMARY: A detailed understanding of the performance of all the imaging modalities available to the stone surgeon in 2013 is vital in order to offer well tolerated and effective imaging strategies for all stages of the patient journey. CT has developed a pre-eminent role in the diagnosis of urinary stone disease, it has also found favour as a valuable surgical planning tool and is being advocated in the surveillance protocols. However, we must keep in mind the risks of radiation exposure in a patient population characterized by youth and a susceptibility to repeated acute disease episodes.

Computed tomography for percutaneous renal access.

Abstract Successful percutaneous nephrolithotomy (PCNL) relies on appropriate preoperative planning and optimal percutaneous access. CT has now become the standard imaging tool for PCNL. For percutaneous renal access, CT may be used for planning access, guiding access, and in the follow-up after access. In this review, we discuss the role of each aspect for percutaneous access in PCNL. In particular, we describe the technique for gaining access using CT, a valuable method in the difficult collecting system.

Three-dimensional CT pyelography for planning of percutaneous nephrostolithotomy: accuracy of stone measurement, stone depiction and pelvicalyceal reconstruction.

Retrospective evaluation of computed tomographic (CT) pyelography before percutaneous nephrostolithotomy (PCNL). Twenty patients with renal calculi underwent CT pyelography using a dedicated protocol. Calculus size, uniformity of contrast excretion and accuracy of calculus and pelvicalyceal (PC) system reconstructions were scored and compared on axial and coronal maximum intensity projections (MIP) and volume reconstructions (VRmovie loops). After contrast medium administration, the size of calculi is accurate on axial images, but underestimated on coronal studies: mean 14.7 mm vs. 14.4 mm (axial) and 17.2 mm vs. 16.1 mm (coronal) for measurements before and after enhancement, respectively (p = 0.11 and 0.03). Uniform contrast medium excretion (median 228 HU; 95% CI 209-266 HU) was sufficiently lower than calculus density (median 845 HU; 95% CI 457-1,193 HU) for precise calculus and pelvicalyceal reconstructions in 87% and 85%, respectively. Coronal MIP scans were rated best for calculus depiction (mean score 2.68 vs. 2.50 and 2.41 for coronal, axial and VRs, respectively; p = 0.14) and VR studies best for PC anatomy (mean score 4.4 vs. 3.73 and 2.89 for VR, coronal and axial studies, respectively; p = <0.0001). Three-dimensional CT pyelography can accurately demonstrate calculus position and spatial relationships of the collecting system before PCNL.

Evaluation of the accuracy of 3-dimensional ultrasonography of the kidney using an in vitro renal model.

OBJECTIVE: Three-dimensional ultrasonography (3DUS) has recently become a reality because of advances in ultrasound probes and machine processing ability. We have developed an anthropomorphic phantom of the human loin to assess both the accuracy of 3DUS of the kidney and its potential usefulness for training in ultrasonographically guided percutaneous renal intervention. METHODS: The model was built with easily available and inexpensive materials such as agar and latex with known ultrasonographic properties. The accuracy of 2-dimensional ultrasonography (2DUS) and 3DUS was assessed by measuring the dimensions of the pelvicalyceal system (PCS) ultrasonographically (pelvis width and calyx diameters) and then comparing these with measurements obtained at the time of construction. Radiology interventional trainees then punctured the PCS with 2DUS and 4-dimensional ultrasonographic (real-time/time-resolved 3DUS) guidance and reported the phantom's performance. RESULTS: The 3-dimensional nature of the model's PCS could be clearly visualized on 2DUS and 3DUS, and the scan characteristics were very similar to those in real life. Measurements using 3DUS proved to be closer to the true dimensions of the model's PCS than those using 2DUS. The mean error percentage for 2DUS measurements was -10.2%, and that for 3DUS was -2.2% (P < 0.0001). Interventional trainees were satisfied with the "tissue feel" and level of difficulty posed on puncturing the phantom. CONCLUSIONS: Three-dimensional ultrasonography proved to be more accurate than 2DUS for intrarenal measurements using this in vitro renal model. Three-dimensional ultrasonography has the potential to ease diagnostic renal scanning with the ability to further scrutinize and postprocess the scanned volumes. The model was realistic in its anthropomorphic properties and simulated human tissue during puncture.

A biphasic response from bladder epithelial cells induced by catheter material and bacteria: an in vitro study of the pathophysiology of catheter related urinary tract infection.

PURPOSE: Catheter associated urinary tract infection is the most common type of hospital acquired infection. An understanding of catheter associated urinary tract infection pathogenesis is needed to improve the control and treatment of these infections. We investigated the relationship among catheter material, bacteria and bladder epithelial cell reaction. MATERIALS AND METHODS: Urinary catheter sections and a clinical isolate of Escherichia coli were added to human bladder carcinoma epithelial cells in vitro in combination or independently. The catheters were rotated for 30 seconds over the cells, followed by incubation. The cytokines interleukin-6 and 8 were measured by enzyme-linked immunosorbent assay as indicators of inflammation and cell membrane disruption was assessed using a lactate dehydrogenase assay. RESULTS: The levels of lactate dehydrogenase release and cytokine production depended on the number of bacteria added. Bacteria grown for 3 days caused greater secretion of cytokines than bacteria grown overnight. Silicone catheter material alone caused immediate damage to cells with increased lactate dehydrogenase in the supernatant but little interleukin-6 or 8 production. Silicone catheters caused significantly less cytokine secretion from bladder cells than latex catheters. Conversely bacteria caused little immediate damage to cells but stimulated cytokine production after 12 hours. CONCLUSIONS: Disruption of bladder epithelial cell membranes in vitro occurred immediately as a result of physical abrasion caused by catheters but delayed inflammation occurred in response to bacterial infection.

Three-dimensional ultrasound reconstruction of the pelvicaliceal system: an in-vitro study.

OBJECTIVES: Three-dimensional (3D) reconstruction of the pelvicaliceal system (PCS) can be helpful for percutaneous renal procedures. 3D reconstruction of the PCS using ultrasound (US) has not been studied. We determined the feasibility and accuracy of 3DUS reconstruction of the PCS in an in vitro model. METHODS: Ten pig kidneys were scanned in vitro using freehand 3DUS (Logiq 9, GE medical systems). Multi-planar reformatted (MPR) and volume rendered (VR) reconstructions of the PCS were processed on a workstation. Using resin casts of the PCS as the reference standard, MPR reconstructions were compared for maximal polar and antero-posterior (AP) PCS length, lower pole infundibular (LPInf) diameter and number of calices. VR movies were compared for number of calices. Three blinded reviewers matched VR movies to casts and given an "anatomical representation" score using a five-point scale. RESULTS: There were no significant differences in maximal AP length, LPInf diameter or number of calices between MPR reconstructions and casts. Maximal polar length between MPR reconstructions and casts were different (t = 6.44, P = 0.0001). VR movie reconstructions underestimated the number of calices visualised (t = 3.23, P = 0.01). A total of 22 out of 30 (73%) 3D VR videos were accurately matched to their casts. The 3D VR median score for anatomical representation was 3 (fair representation). CONCLUSIONS: Three-dimensional ultrasound reconstruction of the porcine PCS is quantitatively comparable to corresponding casts of the PCS. 3D VR movies of the PCS were a fair representation of the PCS anatomy. 3DUS is a potential tool in the planning and execution of percutaneous renal procedures.

The risk of prostate cancer amongst South Asian men in southern England: the PROCESS cohort study.

OBJECTIVE: To reinvestigate whether South Asian men in the UK are at lower risk of being diagnosed with prostate cancer in a UK-based retrospective cohort study and to examine possible reasons that may explain this. PATIENTS AND METHODS: The catchment areas were predefined in four areas of southern England, and age- and race-specific populations for those areas taken from census data. Cases were ascertained through review of multiple hospital sources, while race, other demographic factors, and medical history were determined using questionnaires sent to the men, hospital records review and death certificates. The South Asian group included men of Indian, Bangladeshi and Pakistani origin. RESULTS: There was modest evidence of lower prostate cancer rates in South Asian men compared with their White neighbours (age-adjusted rate ratio 0.81; 95% confidence interval 0.65-1.00). This difference did not reflect less use of prostate-specific antigen (PSA) testing or differences in clinical features at presentation. CONCLUSION: This study provides evidence of a lower incidence of prostate cancer amongst South Asian men living in England, in comparison with their White counterparts. If anything, South Asian men presented with clinical features of earlier disease suggesting that the reduced risk is unlikely to be an artefact of poorer access to health care.

Percutaneous renal intervention: comparison of 2-D and time-resolved 3-D (4-D) ultrasound for minimal calyceal dilation using an ultrasound phantom and fluoroscopic control.

The rapid advances made by ultrasound in recent years have increasingly taken 3-D ultrasound (3DUS) and 4-D ultrasound (4DUS) from the research setting to the patient's bedside. There are still unexplored areas like renal percutaneous intervention, where 4DUS has yet to be proven an effective tool. Ultrasound-only guidance in renal percutaneous access is used in selected well-dilated pelvi-calyceal systems (PCS), and fluoroscopy is often utilized as an adjunct. Our aim was to compare 2-D and 4-D guidance for punctures, with fluoroscopy as control, using an in vitro ultrasound phantom. Agar and latex were the tissue-mimicking materials used for the construction of the phantom. The latex targets were designed to simulate multidirection-facing minimally dilated renal calyces. Two interventional fellows punctured the "calyces" using first 2DUS and then 4DUS guidance, making use of a different set of targets each time. The time to puncture, time to introduction of wire, quality of puncture (judged on fluoroscopy) and global rating of both modalities were documented. There was no significant difference between the times to puncture using 2DUS (1.8 min) and 4DUS (2 min). Nor was there a significant difference in the quality of puncture. 4DUS had a higher median difficulty rating. The multiplanar reformatted (MPR) longitudinal and transverse images were found to be the most useful for needle guidance. Cross hairs in all MPR images were not just useful in aligning the images on target but also as surrogate targets. The phantom was found to be robust, with only one instance of air introduction after 30 punctures. We have found that 4DUS is at least as good as 2DUS in terms of quality of punctures in vitro. The technology still has some way to go as frame rates, transducer size and resolution improve.

Portable ultrasonography and bladder volume accuracy--a comparative study using three-dimensional ultrasonography.

OBJECTIVES: To compare the ultrasound bladder volume accuracy and level of agreement between two portable bladder scanners (Bladderscan and Bardscan) and a three-dimensional ultrasound (3D-US) system. METHODS: A total of 50 healthy volunteers were scanned using the Bladderscan BVI 3000, Bardscan, and 3D-US system (HDI 4000), in random sequence. The BVI3000 is a dedicated bladder volume calculator, and the Bardscan combines real-time ultrasonography with bladder volume calculation. The ultrasound bladder volumes were compared with the voided volume measurements. The volunteers underwent repeat scanning after voiding, and those with a measurable residual volume were excluded from the final analysis. RESULTS: A residual volume was detected in 16 subjects (32%). In the remaining 34 subjects, the mean voided volume +/- standard deviation was 252.9 +/- 167.4 mL (range 33 to 709). A significant correlation (P <0.001) was found between the voided and ultrasound volumes with all three methods (Bardscan, r = 0.97; Bladderscan, r = 0.98; and 3D-US system, r = 0.99). No significant differences were found between the voided volumes and the Bladderscan or 3D-US volumes; however, the Bardscan significantly underestimated the voided volume by a mean of 21.4 mL (t = 2.84, P = 0.0076). The Bland-Altman 95% limit of agreement between the voided and calculated volumes was -64.5 to 107.2 mL, -73.7 to 88.4 mL, and -28.9 to 40.0 mL for the Bardscan, Bladderscan, and 3D-US systems, respectively. CONCLUSIONS: The results of our study have shown that although the Bardscan has the advantages of real-time scanning with portability and instantaneous volume calculation, it is not as accurate as the Bladderscan. The accuracy and level of clinical agreement was greatest when using the 3D-US system to calculate the bladder volume.

What radiation exposure can a patient expect during a single stone episode?

PURPOSE: There is increasing concern about the risks of radiation exposure with the advent of new, more complex imaging modalities. For example, computed tomography (CT), with its obvious advantages, is being more commonly used in the investigation of acute flank pain. The likely radiation exposure a patient can expect during a single complete urinary stone episode was studied. PATIENTS AND METHODS: The hospital records of 60 consecutive unselected patients who had become or were rendered stone-free were studied. The effective radiation doses in milliSieverts (mSV) associated with diagnostic imaging modalities such as intravenous urogram studies and CT scans were calculated for St. George's Hospital. By combining these with the published effective doses for interventional examinations, the total effective dose over an entire stone episode was derived. RESULTS: There were a total of 60 patients with 68 stones (15 renal, 9 in the upper, 12 in the middle, and 32 in the lower ureter), with a median stone burden of 4 mm. Thirty-two patients had procedures performed, including extracorporeal shockwave lithotripsy SWL. Total effective doses ranged from 1.18 to 37.66 mSv (median 5.3 mSv; 95% CI of the median 4.13, 7.61). Renal and proximal ureteral stones resulted in the highest radiation exposures. CONCLUSION: In this study the median radiation dose per stone episode was calculated at 5.3 mSv, with higher doses in those with renal stones and those who required CT scans and other interventions. Monitoring and reduction of radiation exposure is advised for all patients presenting with urolithiasis.