R. C. L. Feneley

Preliminary results of a randomized controlled trial of prophylactic shock wave lithotripsy for small asymptomatic renal calyceal stones

Objective To report a prospective, randomized study to determine whether prophylactic extracorporeal shockwave lithotripsy (ESWL) is justified as a treatment for small, asymptomatic calyceal stones.

Early observations of the effect of extracorporeal shockwave lithotripsy on blood pressure : a prospective randomized control clinical trial

Objective To determine, in a randomized controlled clinical trial, the effect of extracorporeal shock wave lithotripsy (ESWL) on blood pressure.

Prospective study of individuals with long-term urinary catheters colonized with Proteus species

To characterize the variability in the times catheters take to block with encrustation in patients who have Proteus in their urinary flora, and to identify factors responsible for modulating the rate of catheter encrustation and blockage.

Urinary catheter ‘deflation cuff’ formation: clinical audit and quantitative in vitro analysis

Objective  To investigate reports from district nursing staff of difficulty in removing long‐term urinary catheters (LTCs) because of the formation of a ‘cuff’ on deflating the self‐retaining balloon.

Urinary catheters: history, current status, adverse events and research agenda

Abstract For more than 3500 years, urinary catheters have been used to drain the bladder when it fails to empty. For people with impaired bladder function and for whom the method is feasible, clean intermittent self-catheterization is the optimal procedure. For those who require an indwelling catheter, whether short- or long-term, the self-retaining Foley catheter is invariably used, as it has been since its introduction nearly 80 years ago, despite the fact that this catheter can cause bacterial colonization, recurrent and chronic infections, bladder stones and septicaemia, damage to the kidneys, the bladder and the urethra, and contribute to the development of antibiotic resistance. In terms of medical, social and economic resources, the burden of urinary retention and incontinence, aggravated by the use of the Foley catheter, is huge. In the UK, the harm resulting from the use of the Foley catheter costs the National Health Service between £1.0–2.5 billion and accounts for ∼2100 deaths per year. Therefore, there is an urgent need for the development of an alternative indwelling catheter system. The research agenda is for the new catheter to be easy and safe to insert, either urethrally or suprapubically, to be retained reliably in the bladder and to be withdrawn easily and safely when necessary, to mimic natural physiology by filling at low pressure and emptying completely without damage to the bladder, and to have control mechanisms appropriate for all users.

Genotyping of urinary and fecal Proteus mirabilis isolates from individuals with long-term urinary catheters

Bacterial colonization of the urinary tract is probably inevitable in those individuals undergoing long-term urinary catheterization. In approximately half of cases this leads to the complication of catheter encrustation, whereby the drainage lumen of the catheter is recurrently obstructed by crystalline biofilm, causing painful retention of urine or incontinence [1]. This is usually caused by organisms possessing the enzyme urease, particularly Proteus mirabilis [2]. Colonization usually occurs by the ascending route via the catheter, either through the internal drainage lumen as a result of contamination of the drainage apparatus, or along the external catheter surface by bacteria from the urethral meatus [3]. The external route is thought to be more important since closed drainage systems have become standard, and one phenotyping study of bacteriuria in subjects with short-term catheterization suggested an endogenous gastrointestinal origin for several common species [4]. In long-term catheterization, however, the closed system is broken regularly to change the drainage bag, allowing for possible bacterial transfer from exogenous sources. The origin of P. mirabilis colonization is therefore unclear. An understanding of the source of the strains found in longterm catheter users could help in devising protocols to prevent colonization. To investigate this, we have used Dienes typing and pulsed-field gel electrophoresis (PFGE), as both have proved highly discriminatory in previous epidemiological studies of P. mirabilis [5]. Simultaneous samples of bladder urine and feces were taken from 18 long-term catheter users known to have urinary colonization with P. mirabilis. All had been using a catheter for at least 9 months prior to the study. From this group, ten were found to have P. mirabilis in both urine and feces. Three were residents of the same long-term care facility, while the others lived at home and had their catheters managed by visiting community nurses. Five used suprapubic catheters and eight were female. Urine samples were taken from the catheter sampling port. Fecal samples were taken by rectal swab. Samples were refrigerated within 5 min of collection and cultured within 6 h. The media used were colistin–inositol agar [6], cysteine lactose electrolyte-deficient agar and tryptone soya agar (Oxoid, Basingstoke, UK), and plates were incubated for 24 h at 37°C. Isolates were identified using a BBL Crystal system (Becton Dickinson Europe, Meylan, France). Isolated strains of P. mirabilis were stored at −80°C on Microbank beads (Pro-Lab Diagnostics, Neston, UK). Dienes typing and genotyping were performed as previously described by Sabbuba et al. [5]. Dienes typing showed no inhibition lines between any of the paired isolates from the urine and feces of any individual catheter user. In contrast, inhibition lines were seen between all isolates from different subjects. Therefore, Dienes typing indicated each subject was colonized by a distinct P. mirabilis strain, and each strain was present in both the urine and feces of that individual. PFGE genotyping also showed that each subject was colonized by a distinct strain of P. mirabilis. Seven of the ten subjects had genetically indistinguishable strains in both their urine and feces. Three subjects had closely related strains, differing by one genetic event (subjects 2, 8, and 9). There was no relationship among the strains from subjects in the long-term care facility (subjects 4, 6 and 10). Figure 1 shows the DNA profiles of the 20 isolates obtained by the PFGE method. Previous studies have shown that P. mirabilis strains isolated from the crystalline catheter biofilms and bladder calculi, which develop in patients with catheter encrustation, are identical to those found in their urine [5, 7]. Our S. Mathur (*) . R. C. L. Feneley Bristol Urological Institute, Southmead Hospital, Bristol, BS10 5NB, UK e-mail: s.mathur@dial.pipex.com Tel.: +44-117-3771790

A clinical assessment of the performance of a sensor to detect crystalline biofilm formation on indwelling bladder catheters

To test the ability of a sensor developed to signal infection by the organisms that generate the crystalline biofilms that encrust catheters, to give an early warning that encrustation was occurring on patients’ catheters, as the care of many patients undergoing long‐term bladder catheterization is complicated by the encrustation and blockage of their catheters

Developing a strategy to reduce the high morbidity of patients with long-term urinary catheters: the BioMed catheter research clinic.

To assess the idea of managing patients having problems with long‐term catheterization (LTC, normally used when all other methods of bladder management have failed or are unsuitable) in a dedicated clinic, to present a prospective analysis of consecutive new patients attending between February 2002 and October 2006, and to establish the incidence of bladder stones in patients who have recurrent catheter encrustation and blockage.

Developing alternative devices to the long-term urinary catheter for draining urine from the bladder

Abstract The self-retaining urinary catheter is used for long-term drainage of urine from the bladder only as a last resort because of serious associated complications, yet it remains a routine method for managing older and disabled patients with loss of bladder control. Blockage of the catheter from calcified deposits within its lumen is a common occurrence, obstructing the passage of urine and causing an urgent, unpredictable problem for patients, carers and the nursing staff. The need for further research on the subject has been recognized for many years. The SuPort Project aimed to develop an alternative suprapubic urine collection system. This report outlines the approach adopted towards the design and selection of the novel device, the production problems that ensued and the small clinical trial of a modified prototype.