Trends in the use of radiation protection and radiation exposure of European endourologists: a prospective trial from the EULIS-YAU Endourology Group

INTRODUCTION

Due to the radiation exposure for the urology staff during endourology, our aim was to evaluate the trends of radiation protection in the operation room by endourologists from European centers and to estimate their annual radiation.

METHODS

We conducted a multicenter study involving experienced endourologists from different European centers to evaluate whether the protection and threshold doses recommended by the International Commission on Radiation Protection (ICRP) were being followed. A 36-question survey was completed on the use of fluoroscopy and radiation protection. Annual prospective data from chest, extremities, and eye dosimeters were collected during a 4-year period (2017-2020).

RESULTS

Ten endourologists participated. Most surgeons use lead aprons and thyroid shield (9/10 and 10/10), while leaded gloves and caps are rarely used (2/10 both). Six out of ten surgeons wear leaded glasses. There is widespread use of personal chest dosimeters under the apron (9/10), and only 5/10 use a wrist or ring dosimeter and 4 use an eye dosimeter. Two endourologists use the ALARA protocol. The use of ultrasound and fluoroscopy during PCNL puncture was reported by 8 surgeons. The mean number of PCNL and URS per year was 30.9 (SD 19.9) and 147 (SD 151.9). The mean chest radiation was 1.35 mSv per year and 0.007 mSv per procedure. Mean radiation exposure per year in the eyes and extremities was 1.63 and 11.5 mSv.

CONCLUSIONS

Endourologists did not exceed the threshold doses for radiation exposure to the chest, extremities and lens. Furthermore, the ALARA protocol manages to reduce radiation exposure.

International Alliance of Urolithiasis Guideline on Shockwave Lithotripsy

Different international associations have proposed their own guidelines on urolithiasis. However, the focus is primarily on an overview of the principles of urolithiasis management rather than step-by-step technical details for the procedure. The International Alliance of Urolithiasis (IAU) is releasing a series of guidelines on the management of urolithiasis. The current guideline on shockwave lithotripsy (SWL) is the third in the IAU guidelines series and provides a clinical framework for urologists and technicians performing SWL. A total of 49 recommendations are summarized and graded, covering the following aspects: indications and contraindications; preoperative patient evaluation; preoperative medication; prestenting; intraoperative analgesia or anesthesia; intraoperative position; stone localization and monitoring; machine and energy settings; intraoperative lithotripsy strategies; auxiliary therapy following SWL; evaluation of stone clearance; complications; and quality of life. The recommendations, tips, and tricks regarding SWL procedures summarized here provide important and necessary guidance for urologists along with technicians performing SWL. PATIENT SUMMARY: For kidney and urinary stones of less than 20 mm in size, shockwave lithotripsy (SWL) is an approach in which the stone is treated with shockwaves applied to the skin, without the need for surgery. Our recommendations on technical aspects of the procedure provide guidance for urologists and technicians performing SWL.

Impact of COVID-19 on the management and outcomes of ureteric stones in the UK: a multicentre retrospective study

OBJECTIVES

To determine if management of ureteric stones in the UK changed during the coronavirus disease 2019 (COVID-19) pandemic and whether this affected patient outcomes.

PATIENTS AND METHODS

We conducted a multicentre retrospective study of adults with computed tomography-confirmed ureteric stone disease at 39 UK hospitals during a pre-pandemic period (23/3/2019-22/6/2019) and a period during the pandemic (the 3-month period after the first severe acute respiratory syndrome coronavirus-2 case at individual sites). The primary outcome was success of primary treatment modality, defined as no further treatment required for the index ureteric stone. Our study protocol was published prior to data collection.

RESULTS

A total of 3735 patients were included (pre-pandemic 1956 patients; pandemic 1779 patients). Stone size was similar between groups (P > 0.05). During the pandemic, patients had lower hospital admission rates (pre-pandemic 54.0% vs pandemic 46.5%, P < 0.001), shorter mean length of stay (4.1 vs 3.3 days, P = 0.02), and higher rates of use of medical expulsive therapy (17.4% vs 25.4%, P < 0.001). In patients who received interventional management (pre-pandemic 787 vs pandemic 685), rates of extracorporeal shockwave lithotripsy (22.7% vs 34.1%, P < 0.001) and nephrostomy were higher (7.1% vs 10.5%, P = 0.03); and rates of ureteroscopy (57.2% vs 47.5%, P < 0.001), stent insertion (68.4% vs 54.6%, P < 0.001), and general anaesthetic (92.2% vs 76.2%, P < 0.001) were lower. There was no difference in success of primary treatment modality between patient cohorts (pre-pandemic 73.8% vs pandemic 76.1%, P = 0.11), nor when patients were stratified by treatment modality or stone size. Rates of operative complications, 30-day mortality, and re-admission and renal function at 6 months did not differ between the data collection periods.

CONCLUSIONS

During the COVID-19 pandemic, there were lower admission rates and fewer invasive procedures performed. Despite this, there were no differences in treatment success or outcomes. Our findings indicate that clinicians can safely adopt management strategies developed during the pandemic to treat more patients conservatively and in the community.

European Association of Urology Section of Urolithiasis and International Alliance of Urolithiasis Joint Consensus on Retrograde Intrarenal Surgery for the Management of Renal Stones

BACKGROUND

Retrograde intrarenal surgery (RIRS) has become the preferred treatment modality for nephrolithiasis. However, because of ongoing uncertainties regarding the optimal perioperative management, operative technique, and postoperative follow-up, as well as a lack of standardization for outcome reporting, consensus is needed to achieve more uniform clinical practice worldwide.

OBJECTIVE

To develop recommendations for RIRS on the basis of existing data and expert consensus.

DESIGN, SETTING, AND PARTICIPANTS

A protocol-driven, three-phase study was conducted by the European Association of Urology Section of Urolithiasis (EULIS) and the International Alliance of Urolithiasis (IAU). The process included: (1) a nonsystematic review of the literature to define domains for discussion; (2) a two-round modified Delphi survey involving experts in this field; and (3) an additional group meeting and third-round survey involving 64 senior representative members to formulate the final conclusions.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The results from each previous round were returned to the participants for re-evaluation of their decisions during the next round. The agreement threshold was set at 70%.

RESULTS AND LIMITATIONS

The panel included 209 participants who developed 29 consensus statements on the following topics of interest: (1) perioperative infection management; (2) perioperative antithrombotic therapy; (3) fundamentals of the operative technique; and (4) standardized outcome reporting. Although this consensus can be considered as a useful reference for more clinically oriented daily practice, we also acknowledge that a higher level of evidence from further clinical trials is needed.

CONCLUSIONS

The consensus statements aim to guide and standardize clinical practice and research on RIRS and to recommend standardized outcome reporting.

PATIENT SUMMARY

An international consensus on the best practice for minimally invasive surgery for kidney stones was organized and developed by two international societies. It is anticipated that this consensus will provide further guidance to urologists and may help to improve clinical outcomes for patients.

How reliable is endoscopic stone recognition? A comparison between visual stone identification and formal stone analysis

OBJECTIVE

To assess the diagnostic accuracy and intra-observer agreement of endoscopic stone recognition compared with formal stone analysis.

INTRODUCTION

Stone analysis is a corner stone in the prevention of stone recurrence. Although X-ray diffraction and infrared spectroscopy are the recommended techniques for reliable formal stone analysis, this is not always possible, and the process takes time and is costly. Endoscopic stone recognition could be an alternative as it would give immediate information on stone composition.

MATERIAL AND METHODS

Fifteen endourologists predicted stone composition based on 100 videos from ureterorenoscopy. Diagnostic accuracy was evaluated by comparing the prediction from visual assessment with stone analysis by X-ray diffraction. After 30 days, the videos were reviewed again in a random order to assess intra-observer agreement.

RESULTS

The median diagnostic accuracy for calcium oxalate monohydrate was of 54% in questionnaire 1 (Q1) and 59% in questionnaire 2 (Q2), whereas calcium oxalate dihydrate had a median diagnostic accuracy of 75% in Q1 and 50% in Q2. The diagnostic accuracy for calcium hydroxyphosphate was 10% in Q1 and 13% in Q2. The median diagnostic accuracy for calcium hydrogen phosphate dihydrate and calcium magnesium phosphate was 0% in both questionnaires. The median diagnostic accuracy for magnesium ammonium phosphate was in 20% in Q1 and 40% in Q2. The median diagnostic accuracy for uric acid was 22% in both questionnaires. Finally, there was a diagnostic accuracy of 60% in Q1 and 80% in Q2 for cystine. The intra-observer agreement ranged between 45-72%.

CONCLUSION

Diagnostic accuracy of endoscopic stone recognition is limited and intra-observer agreement is below the threshold of acceptable agreement.

Efficacy and safety of the EMS Swiss LithoClast® Trilogy for PCNL: results of the European multicentre prospective study on behalf of European Section of UroTechnology

Purpose

PCNL requires a lithotrite to efficiently break stones, and some devices include active suction to remove the fragments. We set out to determine the efficacy and safety of the Swiss LithoClast® Trilogy, in a prospective European multicentre evaluation and compared it to published stone clearance rates for Trilogy based on surface area (68.9 mm²/min) and using the 3D calculated stone volume (526.7 mm³/min).

Methods

Ten European centres participated in this prospective non-randomized study of Trilogy for PCNL. Objective measures of stone clearance rate, device malfunction, complications and stone-free rates were assessed. Each surgeon subjectively evaluated ergonomic and device effectiveness, on a 1–10 scale (10 = extremely ergonomic/effective) and compared to their usual lithotrite on a 1–10 scale (10 = extremely effective).

Results

One hundred and fifty seven PCNLs using Trilogy were included (53% male, 47% female; mean age 55 years, range 13–84 years). Mean stone clearance rate was 65.55 mm²/min or 945 mm³/min based on calculated 3D volume. Stone-free rate on fluoroscopy screening at the end of the procedure was 83%. Feedback for suction effectiveness was 9.0 with 9.1 for combination and 9.0 for overall effectiveness compared to lithotrite used previously. Ergonomic score was 8.1, the least satisfactory element. Complications included 13 (8.2%) Clavien–Dindo Grade II and 2 (1.3%) Grade III. Probe breakage was seen in 9 (5.7%), none required using a different lithotrite.

Conclusions

We have demonstrated that Trilogy is highly effective at stone removal. From a user perspective, the device was perceived by surgeons to be highly effective overall and compared to the most commonly used previous lithotrite, with an excellent safety profile.

Silicone-hydrocoated ureteral stents encrustation and biofilm formation after 3-week dwell time: results of a prospective randomized multicenter clinical study

OBJECTIVE

To explore the risk of encrustation and biofilm formation for silicone ureteral stents compared to percuflex polymer stents, through a randomized multicenter study.

PATIENTS AND METHODS

Design, setting and participants: A Multicenter, prospective, randomized, single blind, comparative study of hydrocoated silicone stent (Coloplast Imajin^® hydro) versus Percuflex™ Plus stent (Boston Scientific), in 141 patients treated by flexible URS for a kidney stone. The study had ethical committee approval in the respective hospitals. Outcome measurements and statistical analysis: Endpoints related to encrustation were biofilm formation and mineral encrustation after a period of 3-week indwelling time. They were evaluated at removal through a scoring scale of ureteral stents encrustation, infrared spectroscopy and optical microscopy of inner and outer surfaces of tips, angles and along the stent's body. Comparison was performed using ANOVA.

RESULTS

119 stents were available after removal for analysis, 56 in the silicone and 63 in the Percuflex TM Plus group. Mean dwelling duration was 21.8 days for silicone, 22.1 days for PercuflexTM Plus. There was significantly more biofilm on Percuflex™ Plus compared to silicone (1.24 ± 0.08 vs 0.93 ± 0.09, p = 0.0021), and more mineral encrustation (1.22 ± 0.10 vs 0.78 ± 0.11, p = 0.0048), respectively.

CONCLUSIONS

This multicenter randomized study shows that silicone-hydrocoated stents are less prone to encrustation than PercuflexTM Plus after a 3-week dwelling period and confirms the low encrustation potential of silicone.

Retrograde migration of a vesicoureteric junction calculus: A potential pitfall of the noncontrast limited pelvic computerized tomography

Retrograde ureteric calculus migration is a rare phenomenon. Herein, we report two such cases where each patient presented with a calculus, measured at 5 mm and 6 mm, respectively, at the vesicoureteric junction (VUJ) on noncontrast computerized tomography kidneys, ureters, and bladder (CTKUB). Following acute presentation with renal colic, each patient opted for conservative management of their ureteric stone and became asymptomatic when undergoing their follow-up imaging. The first patient underwent a follow-up noncontrast limited pelvic computerized tomography (CT) where it had appeared that the radiolucent VUJ calculus had passed. This stone was then discovered incidentally 3 months later in the upper ureter when the patient had undergone a CT colonography. The other patient underwent a follow-up X-ray KUB where the stone was shown to have migrated to the lower renal pole calyx which was confirmed with noncontrast CTKUB imaging. In all reported cases of retrograde VUJ calculus migration, the use of a noncontrast limited pelvic CT scan either missed or would have missed this phenomenon. This potential pitfall of the noncontrast limited pelvic CT scan should be appreciated and the use of full upper renal tract imaging should be considered for the follow-up of radiolucent VUJ calculus cases whereby there is no clear history of calculus passage.

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.

Case 267: Cecureterocoele Manifesting in a Man with Infertility

History A 28-year-old man presented with lifelong anejaculation, which had become an issue because of family planning. The patient had a history of normal erections and experienced the sensation of orgasm without ever ejaculating. On physical examination, both testes were present in the scrotum, with normal dimensions and a normal epididymis bilaterally. The patient had a slightly tender left testicle, and digital rectal examination findings were normal. The patient underwent further investigation for the possibility of retrograde ejaculation with urine cytology, the results of which were negative. Genetic testing was performed to exclude Y chromosome microdeletions. Serum-luteinizing and follicle-stimulating hormone levels were normal, with a borderline low level of testosterone (7.6 nmol/L; normal range, 8.0-29.0 nmol/L). All other pertinent laboratory results were noncontributory. Pelvic MRI was requested to exclude an anatomic cause of anejaculation. MRI was performed in accordance with the standard clinical prostate protocol, with a dynamic contrast material-enhanced study. CT of the upper abdomen was also performed. The patient subsequently underwent cystoscopy, which revealed an intravesicular fluid-filled mass near the left ureteric orifice.

Case 267

History A 28-year-old man presented with lifelong anejaculation, which had become an issue because of family planning. The patient had a history of normal erections and experienced the sensation of orgasm without ever ejaculating. On physical examination, both testes were present in the scrotum, with normal dimensions and a normal epididymis bilaterally. The patient had a slightly tender left testicle, and digital rectal examination findings were normal. The patient underwent further investigation for the possibility of retrograde ejaculation with urine cytology, the results of which were negative. Genetic testing was performed to exclude Y chromosome microdeletions. Serum-luteinizing and follicle-stimulating hormone levels were normal, with a borderline low level of testosterone (7.6 nmol/L; normal range, 8.0-29.0 nmol/L). All other pertinent laboratory results were noncontributory. Pelvic MRI was requested to exclude an anatomic cause of anejaculation. MRI was performed in accordance with the standard clinical prostate protocol, with a dynamic contrast material-enhanced study ( Figs 1 - 3 ). CT of the upper abdomen was also performed ( Fig 4 ). The patient subsequently underwent cystoscopy, which revealed an intravesicular fluid-filled mass near the left ureteric orifice ( Fig 5 ). Figure 1a: (a) Coronal and (b, c) axial fast spin-echo T2-weighted MR images of the pelvis, with b being superior to c. Figure 1b: (a) Coronal and (b, c) axial fast spin-echo T2-weighted MR images of the pelvis, with b being superior to c. Figure 1c: (a) Coronal and (b, c) axial fast spin-echo T2-weighted MR images of the pelvis, with b being superior to c. Figure 2a: (a) Coronal T2-weighted (repetition time msec/echo time msec, 4574/86.5) MR image of the pelvis. (b) Axial T2-weighted (3000/85.4) MR image of the pelvis. Figure 2b: (a) Coronal T2-weighted (repetition time msec/echo time msec, 4574/86.5) MR image of the pelvis. (b) Axial T2-weighted (3000/85.4) MR image of the pelvis. Figure 3: Unenhanced axial fat-saturated T1-weighted (6.2/3.1) MR images. Figure 4: Coronal CT urogram. Figure 5: Image obtained at cystoscopy.

A clinical evaluation of the new digital single-use flexible ureteroscope (UscopePU3022): an international prospective multicentered study

Introduction

We assessed the clinical performance of a new digital single-use flexible ureteroscope (UscopePU3022).

Material and methods

A prospective cohort study was carried out across 11 centers (July-Oct. 2017). The UscopePU3022 was assessed regarding ease of insertion; deflection, image quality, maneuverability and overall performance using either a visual analog* or Likert scale.

Results

A total of 56 procedures were performed in 11 centers (16 surgeons) with the indication being renal stones in 83%. The median score for ease of scope insertion was 10 (3-10). Intraoperative maneuverability was rated as 'good' in 38% and 'very good' in 52%. Visual quality was rated as 'poor or bad' in 18%, 'fair' in 37% and 'good or very good' in 43%. Two scopes failed intraoperatively (4%). Preoperative and postoperative median upward and downward deflection was 270 degrees. Compared to standard flexible ureteroscopy (f-URS) maneuverability was rated as 'equivalent' in 30% and 'better' in 60%; visual quality was 'worse' in 38% and 'equivalent or better' in 62%; limb fatigue scores were 'better' in 86%; and overall performance was 'worse' in 55% and 'equivalent or better' in 45%.

Conclusions

UscopeTM3022 performed well with regards to maneuverability, deflection and limb fatigue and appears to be at least non-inferior to standard f-URS with regards to these parameters. Poor image quality is a concern for UscopePU3022 with it receiving a low overall performance rating when compared to standard f-URS. Despite this it scored highly when investigators were asked if they would use it in their practice if it was cost-effective to do so.

British Association of Urological Surgeons standards for management of acute ureteric colic

These guidelines have been developed by the British Association of Urological Surgeons to give a framework to clinicians, based primarily in the UK, for the management of patients presenting acutely with ureteric colic. They have been developed by consensus with reference to the American Urological Association/Endourological Society guidelines on the surgical management of stones and the European Association of Urology guidelines on urolithiasis, and adapted to the logistics of those practicing within the National Health Service. Grades of recommendation and levels of evidence are based upon the system adopted by the European Association of Urology.

Which Is Better? "Live" Surgical Broadcasts vs "As-Live" Surgical Broadcasts

INTRODUCTION

Recently, the role of "live" surgical broadcasts (LSB) as an educational tool to demonstrate surgical techniques at conferences has been challenged, with concerns surrounding the well-being and safety of the patient as well as the surgeon. There have been notions that "as-live" surgical broadcasts (ALSB), prerecorded unedited videos showing either the whole procedure or key features, may be educationally superior. Our study was hence conducted to determine which was deemed better by a diverse group of international urologists.

METHODS

All participants of the World Congress of Endourology held in October 2015 in London were invited to complete an electronic survey using the conference app regarding LSB demonstrations compared with ASLB, before the congress and again after the congress. Only ALSB videos were used in the congress.

RESULTS

Both pre- and postconference surveys showed that 76.9% and 78.2% of the participants, respectively, perceived that more teaching could be achieved in less time using ASLB. 52.8% and 60.3% of respondents indicated ALSB as being superior to LSB before and after the conference, respectively. Furthermore, 52.8% and 54.5% of respondents regarded ALSB videos as having more educational value than LSB before and after the conference, respectively.

CONCLUSION

There was little perceived difference between ALSB and LSB, showing that ALSB are at least noninferior as an educational tool. In view of the numerous ethical and logistical issues with LSB, we would advocate ASLB as the educational tool of choice for future surgical demonstration at conferences.

Would You Want to Be the Patient? "Live Surgical Broadcast" or "As-Live Unedited Surgical Broadcast"

OBJECTIVE

To evaluate patient safety, educational value, and ethical issues surrounding "Live surgical broadcast" (LSB) and "As-live surgical broadcast" (ALB) using data obtained from urologic delegates attending two recent endourology meetings in the United Kingdom.

SUBJECTS AND METHODS

Two hundred twelve delegates at the UK section meeting of the Société Internationale d'Urologie (SIU) were invited to complete an online survey using SurveyMonkey(®) to compare their previous perceptions of LSB and ALB, and to compare their current experience of ALB to previous experience of LSB. One hundred three delegates at the British Association of Urological Surgeons (BAUS) Endourology meeting used live voting keypads to compare their experience of LSB and ALB simultaneously, as well as comparing their current experience of ALB to previous experience of LSB. Responses were recorded using a Likert scale.

RESULTS

One hundred sixty-five responses were analyzed from the meetings. Most delegates were in specialist practice as a consultant or trainee (89.1%). LSB had been witnessed more than ALB (87.1% vs 66.6%, p=0.049). Based on previous experiences, the educational value of both formats was felt similar, but delegates felt there were significant patient safety benefits with ALB over LSB. Delegates were significantly less likely to recommend a friend or family, or volunteer themselves to be a patient in an LSB setting. On-the-day comparison of LSB and ALB shows a similar educational value to both formats, but with significantly less concern for the surgeon and patient's outcome with ALB.

CONCLUSION

ALB offers similar educational opportunities to delegates when compared with LSB, while appearing to offer significant welfare benefits to both surgeon and patient. Further studies are required to objectively quantify these subjective observations.

Use of the probability of stone formation (PSF) score to assess stone forming risk and treatment response in a cohort of Brazilian stone formers

INTRODUCTION

The aim was to confirm that PSF (probability of stone formation) changed appropriately following medical therapy on recurrent stone formers.

MATERIALS AND METHODS

Data were collected on 26 Brazilian stone-formers. A baseline 24-hour urine collection was performed prior to treatment. Details of the medical treatment initiated for stone-disease were recorded. A PSF calculation was performed on the 24 hour urine sample using the 7 urinary parameters required: voided volume, oxalate, calcium, urate, pH, citrate and magnesium. A repeat 24-hour urine sample was performed for PSF calculation after treatment. Comparison was made between the PSF scores before and during treatment.

RESULTS

At baseline, 20 of the 26 patients (77%) had a high PSF score (> 0.5). Of the 26 patients, 17 (65%) showed an overall reduction in their PSF profiles with a medical treatment regimen. Eleven patients (42%) changed from a high risk (PSF > 0.5) to a low risk (PSF < 0.5) and 6 patients reduced their risk score but did not change risk category. Six (23%) patients remained in a high risk category (> 0.5) during both assessments.

CONCLUSIONS

The PSF score reduced following medical treatment in the majority of patients in this cohort.

Measuring stone volume - three-dimensional software reconstruction or an ellipsoid algebra formula?

OBJECTIVES

To determine the optimal method for assessing stone volume, and thus stone burden, by comparing the accuracy of scalene, oblate, and prolate ellipsoid volume equations with three-dimensional (3D)-reconstructed stone volume. Kidney stone volume may be helpful in predicting treatment outcome for renal stones. While the precise measurement of stone volume by 3D reconstruction can be accomplished using modern computer tomography (CT) scanning software, this technique is not available in all hospitals or with routine acute colic scanning protocols. Therefore, maximum diameters as measured by either X-ray or CT are used in the calculation of stone volume based on a scalene ellipsoid formula, as recommended by the European Association of Urology.

METHODS

In all, 100 stones with both X-ray and CT (1-2-mm slices) were reviewed. Complete and partial staghorn stones were excluded. Stone volume was calculated using software designed to measure tissue density of a certain range within a specified region of interest. Correlation coefficients among all measured outcomes were compared. Stone volumes were analysed to determine the average 'shape' of the stones.

RESULTS

The maximum stone diameter on X-ray was 3-25 mm and on CT was 3-36 mm, with a reasonable correlation (r = 0.77). Smaller stones (<9 mm) trended towards prolate ellipsoids ('rugby-ball' shaped), stones of 9-15 mm towards oblate ellipsoids (disc shaped), and stones >15 mm towards scalene ellipsoids. There was no difference in stone shape by location within the kidney.

CONCLUSIONS

As the average shape of renal stones changes with diameter, no single equation for estimating stone volume can be recommended. As the maximum diameter increases, calculated stone volume becomes less accurate, suggesting that larger stones have more asymmetric shapes. We recommend that research looking at stone clearance rates should use 3D-reconstructed stone volumes when available, followed by prolate, oblate, or scalene ellipsoid formulas depending on the maximum stone diameter.

Capsaicin receptor VR1 and ATP-gated ion channel P2X3 in human urinary bladder

OBJECTIVES

To determine the presence, distribution and molecular forms of the vanilloid receptor VR1, and confirm the presence and distribution of the ATP-gated ion channel P2X3 in the human urinary bladder. Materials and methods Normal urinary bladder tissues were obtained at postmortem from four subjects. Eight urinary bladder biopsies were also taken from patients with detrusor hyper-reflexia treated with intravesical resiniferatoxin. The specimens were studied using affinity-purified specific antibodies to VR1 and P2X3 by Western blotting and immunocytochemistry, and compared with immunostaining using antibodies to the pan-neuronal marker PGP 9.5 and Schwann cell marker S-100.

RESULTS

VR1- and P2X3-immunoreactive fine nerve fibres were scattered throughout the suburothelium of the normal bladder and cystoscopic biopsies, and traversed the muscle layer. They had a similar distribution to PGP 9.5-immunoreactive fibres, but there were fewer, suggesting localization in subsets of axons. Western blot studies showed an expected 100-kDa VR1 protein and a P2X3-immunoreactive 66-kDa protein. Conclusion VR1 and P2X3 are present in the human urinary bladder and may contribute to distinct pathophysiological states of bladder overactivity, in accord with their differential expression in sensory neurones. Intravesical vanilloids act via VR1 and are effective in the treatment of detrusor hyper-reflexia. P2X3 may represent a selective therapeutic target for other causes of overactive bladder.

Presentation of thyroid carcinoma as a thrombosed external jugular vein, with intraluminal tumour thrombus in the great veins

Carcinoma of the thyroid most commonly presents as an asymptomatic thyroid nodule. Some types of thyroid carcinoma show vascular invasion, but this is usually microscopic.(1,2)It is rare for such invasion to involve the great veins and be macroscopic. There are 18 such reports in the literature to date.(3-12)We report a case of a carcinoma of the thyroid that presented due to the presence of tumour thrombus within the external jugular vein, where thrombus was also seen within the great veins.

Results of holmium laser resection of the prostate for benign prostatic hyperplasia

PURPOSE

To assess the results of holmium laser resection of the prostate (HoLRP) in the treatment of benign prostatic hyperplasia.

PATIENTS AND METHODS

Since October 1996, 259 patients have undergone elective HoLRP. Peak urinary flow rates (Qax), IPSS scores, and duration of catheterization and hospital stay from admission to discharge catheter free were used as outcome measures.

RESULTS

There were no perioperative deaths nor cases of transurethral resection syndrome. Two patients required blood transfusion. The mean duration of catheterization was 1.6 days and the mean hospital stay 2.9 days. The mean IPSS decreased from 21.0 preoperatively to 7.0 at 1 year, whilst the Qmax increased from 10.5 mL/sec to 20.5 mL/sec.

CONCLUSION

The HoLRP technique is a safe and effective treatment for benign prostatic hyperplasia, allowing resection of the prostate at the level of the capsule with minimal bleeding or fluid absorption and with results equivalent to those of standard transurethral resection.

Lateral ligaments of the rectum: an anatomical study

BACKGROUND

The lateral ligaments of the rectum are surrounded by confusion and misconception. Their identification before 'hooking them on the finger', clamping and ligating is considered in many surgical texts to be an essential step in mobilization of the rectum. By contrast, it is the experience of many colorectal surgeons that the mesorectum can be dissected out either by diathermy or sharp dissection alone.

METHODS

Dissection in the mesorectal plane was performed on 28 cadaveric pelves.

RESULTS

In ten of the pelves, no connective tissue structure crossed from the pelvic side wall to the rectum. The remaining 18 had only very insubstantial connective tissue strands crossing this space. A total of 17 middle rectal arteries were found, all of them unilateral. Fourteen of these vessels crossed the mesorectum independent of any structure, while the remainder were part of a neurovascular bundle with a connective tissue element.

CONCLUSION

It is proposed that the 'lateral ligaments' of the rectum do not exist and that the term should be dropped from surgical texts. When present, the middle rectal artery is a small vessel, close to the pelvic floor. The entire rectum may be mobilized by sharp dissection without the need for clamping or ligation of any significant structure.