Oliver Wiseman

Long-term results of sacral neuromodulation for women with urinary retention.

To review the long‐term results of sacral nerve stimulation in the treatment of women with Fowlers syndrome, over a 6‐year period at one tertiary referral centre.

Meta-analysis showing the beneficial effect of α-blockers on ureteric stent discomfort.

Study Type – Therapy (systematic review)

MAXIMUM URETHRAL CLOSURE PRESSURE AND SPHINCTER VOLUME IN WOMEN WITH URINARY RETENTION

PURPOSE In 1988 a syndrome of isolated urinary retention in young women that is associated with electromyographic abnormality of the striated urethral sphincter was described. It was hypothesised that urinary retention resulted from a failure of sphincter relaxation. The electromyographic abnormality causes overactivity of the muscle and may induce changes of work hypertrophy. If the hypothesis that the electromyographic abnormality is the cause of urinary retention is correct, we would expect the urethral sphincter to be enlarged and the urethral pressure profile to be increased in these women. We evaluated the role of static urethral pressure profilometry and transvaginal ultrasound in women in urinary retention. MATERIALS AND METHODS A total of 66 women in complete or partial urinary retention underwent electromyography of the striated urethral sphincter using a concentric needle electrode, followed by urethral pressure profile and/or urethral sphincter volume measurement by transvaginal ultrasound. RESULTS Maximum urethral closure pressure plus or minus standard deviation was significantly increased in patients with versus without the electromyographic abnormality (103 +/- 26.4 versus 76.7 +/- 18.4 cm. water, p <0.001). Maximum urethral sphincter volume was also increased in women with versus without the abnormality (2.29 +/- 0.64 versus 1.62 +/- 0.32 cm.3, p <0.001). CONCLUSIONS The results of this study are consistent with the hypothesis that a local sphincter abnormality is the cause of urinary retention in a subgroup of women. Urethral pressure profilometry and sphincter volume measurement are useful for assessing these cases, especially when sphincter electromyography is not readily available.

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

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.

The dilemma of post-ureteroscopy stenting

Proponents of post-URS stenting often quote the anecdote of the memorable patient who, having not been stented, developed pain and/or sepsis requiring an emergency return to theatre for stenting. Others suggest that a stent is akin to a comfort blanket allowing them, if not the patient, to sleep easier after the procedure. European Association of Urology (EAU) Guidelines [1] recommend that ‘stents be inserted in patients who are at increased risk of complications (e.g. residual fragments, bleeding, perforation, UTIs or pregnancy) and in all doubtful cases, to avoid stressful emergencies’. Furthermore, most urologists would be inclined to place a stent after URS in a solitary kidney, in patients with renal impairment and to facilitate future access.

Assessment of Stone Complexity for PCNL: A Systematic Review of the Literature, How Best Can We Record Stone Complexity in PCNL?

INTRODUCTION This study aims to systematically review the literature reporting tools for scoring stone complexity and the stratification of outcomes by stone complexity. In doing so, we aim to determine whether the evidence favors uniform adoption of any one scoring system. METHODS PubMed and Embase databases were systematically searched for relevant studies from 2004 to 2014. Reports selected according to predetermined inclusion and exclusion criteria were appraised in terms of methodologic quality and their findings summarized in structured tables. RESULTS After review, 15 studies were considered suitable for inclusion. Four distinct scoring systems were identified and a further five studies that aimed to validate aspects of those scoring systems. Six studies reported the stratification of outcomes by stone complexity, without specifically defining a scoring system. All studies reported some correlation between stone complexity and stone clearance. Correlation with complications was less clearly established, where investigated. CONCLUSIONS This review does not allow us to firmly recommend one scoring system over the other. However, the quality of evidence supporting validation of the Guys Stone Score is marginally superior, according to the criteria applied in this study. Further evaluation of the interobserver reliability of this scoring system is required.

Salvage of liver transplant with hepatolithiasis by percutaneous transhepatic cholangioscopic hepatolithotomy

Dear Sirs, Hepatolithiasis, whilst endemic in East Asia, is rare in the West, where prevalence is less than 1% of all cholelithiasis [1]. The aetiology is incompletely understood, but biliary stasis, infection and excessive mucin production appear to be important factors [1,2]. Hepatolithiasis is associated with significant morbidity, often characterized by recurrent cholangitis that can result in the development of life-threatening sepsis, hepatic abscesses, secondary biliary cirrhosis and cholangiocarcinoma [1]. The management of hepatolithiasis is challenging, with high rates of treatment failure and recurrence. Although the standard approach to managing this condition is hepatic resection [2,3], percutaneous transhepatic cholangioscopic hepatolithotomy (PTCHL) offers a safe and minimally invasive alternative treatment option [1,4–7]. Little has been reported on the incidence or management of hepatolithiasis after liver transplantation. Here, we describe how PTCHL allowed us to salvage the graft and avoid the risks of abdominal surgery in a complex liver transplant recipient. A 23-year-old female was referred to our centre for assessment and management of hepatolithiasis. She had undergone liver transplantation aged three in 1992 (segments 2 and 3 of an adult liver), for alpha-1 antitrypsin deficiency. Eleven days postoperatively, she required biliary reconstruction and had a Roux-en-Y hepatico-jejunostomy fashioned. Six months later, she presented with internal herniation through the roux-loop window in the transverse mesocolon resulting in extensive small bowel ischaemia. She had a stormy postoperative course, and over the subsequent 2 months, she underwent 10 relook laparotomies for various complications including further ischaemia and overall had approximately 170 cm of small bowel resected, including segments from the roux loop. (The hepaticojejunostomy did not require revision.) She developed short bowel syndrome and remained dependent on total parenteral nutrition for many years. However, over last 5 years, she has managed to sustain with oral intake with periodic intravenous vitamin and mineral supplementation. Although her liver graft function remained good throughout this period, she had intermittently deranged LFTs. A biopsy performed in 2010 had revealed a healthy graft. During the 6 months prior to referral, she experienced recurrent episodes of cholangitis with multiple hospital admissions. MRCP performed at the referring hospital demonstrated intrahepatic duct dilatation and the presence of intrahepatic filling-defects suggestive of stones which were confirmed on PTC. She was subsequently referred to our centre. To clarify the ductal anatomy and assess the distribution of stones, we performed a further PTC. This confirmed multiple stones centrally within the intrahepatic ducts. Although the hepatico-jejunostomy was patent, the adjoining 5-cm segment of the roux loop was noted to be narrowed, but with free flow of contrast (Fig. 1a). CT angiography demonstrated patent hepatic arterial and portal venous inflow suggesting this was not a biliary cast syndrome (BCS). A range of management options were considered by the multidisciplinary team, including liver resection, biliary exploration and retransplantation (potentially multivisceral in view of her short gut syndrome). Considering her history, prior good graft function and histology, and in the absence of intrahepatic cholangiopathy or biliary strictures, attempting to salvage her graft with minimally invasive PTCHL was felt to be most appropriate in the first instance. Our unit had previous experience of performing this procedure in the nontransplant setting. The procedure was performed in conjunction with an interventional radiologist and urologist (with experience of percutaneous nephrolithotomy). Firstly, percutaneous transhepatic biliary drainage was established at an optimal position that would allow access to most of the biliary tree. This tract was allowed to mature for 3 weeks. Under general anaesthesia, the tract was dilated using serial dilators to permit introduction of a 28F Amplatz access sheath (Boston Scientific Corp Natick, MA, US). Using a nephroscope (26 Ch, Karl Storz), the intrahepat-

Hospital Volume Does Not Influence the Safety of Percutaneous Nephrolithotomy in England: A Population-Based Cohort Study.

PURPOSE This study aims to investigate the relationship between hospital case volume and safety-related outcomes after percutaneous nephrolithotomy (PCNL) within the English National Health Service (NHS). PATIENTS AND METHODS The study used the Hospital Episode Statistics (HES) database, a routine administrative database, recording information on operations, comorbidity, and outcomes for all NHS hospital admissions in England. Records for all patients undergoing an initial PCNL between April 1, 2006 and March 31, 2012 were extracted. NHS trusts were divided into low-, medium-, and high-volume groups, according to the average annual number of PCNLs performed. We used multiple regression analyses to examine the associations between hospital volume and outcomes incorporating risk adjustment for sex, age, comorbidity, and hospital teaching status. Postoperative outcomes included: Emergency readmission, infection, and hemorrhage. Mean length of stay was also measured. RESULTS There were 7661 index elective PCNL procedures performed in 163 hospital trusts, between April 2006 and March 2012. There were 2459 patients who underwent PCNL in the 116 units performing fewer than 10 PCNL procedures per year; 2643 patients in the 37 units performing 10 to 19 procedures per year; and 2459 patients in the 9 hospitals performing more than 20 procedures per year. For low-, medium-, and high-volume trusts, there was little variation in the rates of emergency readmission (L 9.7%, M 9.3%, H 8.4%), infection (3.0%, 4.2%, 3.8%), or hemorrhage (1.3%, 1.5%, 1.5%), and there was no statistical evidence that volume was associated with adjusted outcomes. Mean length of stay was slightly shorter in the medium- (5.0 days) and high-volume (5.0) groups compared with the low-volume group (5.3). The effect remained statistically significant after adjusted for confounding. CONCLUSION Hospital volume was not associated with emergency readmission, infection, or hemorrhage. Length of stay appears to be shorter in higher volume units.

Radiation dosage in the urolithiasis population: Do we over-radiate our patients?

Introduction: There is increasing concern about the amount of radiation that patients with urolithiasis receive. Ensuring patients are exposed to the minimum necessary radiation is imperative. Here we review the radiation dosages that newly diagnosed urolithiasis patients received in the year following their presentation, both those presenting acutely and those referred electively. Patients and methods: A retrospective study of 95 treatment-naïve patients (47 acute, 48 elective) referred for management of urolithiasis was undertaken. The analysis included all imaging modalities related to stone disease for both patient groups within one year following presentation. The total effective dose (mSV) in one year was calculated by summing the dose for each individual radiation exposure. Results: An average of 5.6 radiological investigations (range 1–14) was carried out for acute patients and 4.57 for elective patients (range 1–11). The mean total effective dose was 14.45 mSV for the acute cases and 12.87 mSV for the elective cases. The maximum radiation dose reached 30.1 mSV in acute patients and 36.51 mSV in elective ones. None of the patients exceeded the maximal annual dose recommended by the International Commission on Radiological Protection (ICRP) of 50 mSV. Conclusion: Management of acute and elective urolithiasis patients can be achieved with acceptable radiation dose exposure. It is extremely important to keep the hazards of radiation in mind whilst managing patients with urolithiasis and clinicians need to remember adherence to the ALARA principle.

Early multicentre experience of ultra-mini percutaneous nephrolithotomy in the UK

Objectives: Ultra-mini percutaneous nephrolithotomy (UMP) is a novel technique recently introduced allowing percutaneous renal access to stones using a specially modified 11 or 13 Fr sheath, a 6 Fr nephroscope, and permits laser fragmentation and stone evacuation. This study aimed to review the early practice of UMP in the UK. Methods: All centres in the UK which had performed UMP were contacted to submit data. Data were submitted to a central database from nine centres around the UK who performed UMP between July 2013 and December 2014. Data were collected on patient, stone, operative factors and outcomes. Results: A total of 32 UMP cases were performed in the contributing centres. Stone size ranged from 7 mm×5 mm to 24 mm×24 mm across the 32 cases, with a mean of 13 mm×10 mm. Stone-free rates were excellent with 31/32 cases stone-free post procedure; 26/32 patients were left without a nephrostomy tube. Complications were uncommon; there were two Clavien 1 complications in this series (6%). Conclusion: This study has shown the efficacy of UMP during its introduction into UK practice. It is likely that UMP will become a useful addition to the armamentarium to treat renal stones, especially smaller stones in the lower pole calyx, and in specialised cases such as paediatric stone disease and in patients with stones in calyceal diverticulae.