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

Innovating Indwelling Catheter Design to Counteract Urinary Tract Infection

BACKGROUND AND OBJECTIVE

Bacteriuria is anticipated in long-term indwelling catheter (IDC) use, and urinary tract infections (UTIs) and related issues are common. Defence mechanisms against infection are undermined by the presence of a Foley catheter, and adjustments to design could influence UTI risk.

METHODS

We reviewed the various aspects of IDCs and ureteric stent designs to discuss potential impact on UTI risk.

KEY FINDINGS AND LIMITATIONS

Design adaptations have focussed on reducing the sump of undrained urine, potential urinary tract trauma, and bacterial adherence. Experimental and computational studies on ureteral stents found an interplay between urine flow, bacterial microcolony formation, and accumulation of encrusting particles. The most critical regions for biofilm and crystal accumulation are associated with low shear stress. The full drainage system is the functioning unit, not just the IDC in isolation. This means reliably keeping the drainage system closed and considering whether a valve is preferred to a collection bag. Other developments may include one-way valves, obstacles to "bacterial swimming", and ultrasound techniques. Preventing or clearing IDC blockage can exploit access via the lumen or retaining balloon. Progress in computational fluid dynamics, energy delivery, and soft robotics may increase future options. Clinical data on the effectiveness of IDC design features are lacking, which is partly due to reliance on proxy measures and the challenges of undertaking trials.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Design changes are legitimate lines of development, but are only indirect for UTI prevention. Modifications may be advantageous, but might potentially bring problems in other ways. Education of health care professionals can improve UTIs and should be prioritised.

PATIENT SUMMARY

Catheters used to help bladder drainage can cause urinary infections, and improvements in design might reduce the risk. Several approaches are described in this review. However, proving that these approaches work is a challenge. Training professionals in the key aspects of catheter care is important.

Parental home removal of urethral catheters after urological surgery-a prospective benchmarking study

INTRODUCTION

Many urological operations require placement of a urethral Foley catheter. The catheter often needs to remain in situ for a period of time after discharge; and patients subsequently require either a further hospital admission or community nurse review for catheter removal. Parents can easily remove the catheter at home by cutting the balloon port. This disrupts the valve and hence deflates the retaining balloon, thereby facilitating spontaneous passage of the catheter. The authors introduced this practice to their institution.

AIM

The aim was to assess safety and success of parental home catheter removal.

METHODS

A prospective data study was performed in a large pediatric urology center over a 12-month time period. Patients <16 years after single-stage hypospadias repair or other penile surgery were included on a voluntary basis. Parents of eligible patients were instructed verbally and with an information leaflet, including date for removal. Telephone follow-up after removal was undertaken to assess the outcome.

RESULTS

Thirty-eight patients were included over a 12-month time period. Patient age ranged from 9 months to 12 years (median age 2.5 years). The majority (82%) of patients had required a catheter after hypospadias repair. Home catheter removal was successful in 92% cases. Three children required professional support for catheter removal. Median time until catheter passage was 3 h (range 0-24 h). Considering that cost for day case admission for catheter removal averages at 130£ per patient, home catheter removal saved the NHS 4550£ in the time period.

DISCUSSION

This is the first study to report the safety and feasibility of parental home catheter removal by cutting the balloon port valve in the pediatric population. It offers a number of distinct advantages compared with traditional methods for removal. These include, namely, (i) positive patient experience: catheter removal in a familiar environment by a relative minimizes stressful experiences for the family; (ii) minimal trauma to healing tissues through spontaneous catheter passage; and (iii) health care-related cost savings. This was an initial benchmarking study, so patient numbers were relatively small. Nevertheless, it shows that the method is safe and received positive parental feedback.

CONCLUSION

Parental home removal of a urethral catheter is a feasible and safe alternative to catheter removal by a health-care professional. It minimizes parental anxiety and inconvenience related to the catheter removal appointment and allows for significant cost savings.

Innovating urinary catheter design: An introduction to the engineering challenge

Every day, people around the world rely on intermittent and indwelling urinary catheters to manage bladder dysfunction, but the potential or actual harm caused by these devices is well-recognised. Current catheter designs can cause urinary tract infection and septicaemia, bladder and urethral trauma and indwelling devices frequently become blocked. Furthermore, the devices can severely disrupt users' lives, limiting their daily activities and can be costly to manage for healthcare providers. Despite this, little significant design innovation has taken place in the last 80 years. In this article current catheter designs and their limitations are reviewed, common catheter-associated problems are outlined and areas of design ripe for improvement proposed. The potential to relieve the individual and economic burden of catheter use is high.

Efficacy of using Zaontz urethral stent in hypospadias repair by the Face, Legs, Activity, Cry, Consolability (FLACC) scale: A prospective study

INTRODUCTION

The developments in hypospadias surgical techniques and materials are intended to improve surgery outcomes and patient comfort. The aim of this study is to determine the effect of the Zaontz urethral stent (ZUS) (Cook Medical) on patient comfort and surgical success rates in children undergoing hypospadias surgery.

METHODS

A feeding tube was used to repair 46 cases of primary distal hypospadias, and ZUS (6F, 8F, and 10F in diameter) was used to repair to 31 cases of primary distal hypospadias between December 2009 and June 2011 in our clinic. ZUS was compared with the feeding tube in terms of surgical success rates and patient comfort in assessments made during postoperative periods.

RESULTS

The patients with ZUS were followed with a stent for seven days postoperatively, as were the patients with the feeding tube. There was no statistical difference between the two groups in terms of fistula formation (p>0.05). Patient comfort was evaluated by the Face, Legs, Activity, Cry, Consolability (FLACC) scale on the first and third postoperative days, and a statistically significant difference was observed in favour of ZUS on the third postoperative day (p<0.05).

CONCLUSIONS

Compared with a feeding tube in hypospadias repair, ZUS does not make any contribution to the urinary fistula rates. However, ZUS may have an advantage in terms of patient comfort in the postoperative followup. On the other hand, the small number of patients and the high price of the ZUS were the most important limitations. Prospective, randomized trials are needed to assess efficacy and cost.

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

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.

A practical approach to difficult urinary catheterizations

Routine placement of transurethral catheters can be challenging in some situations, such as urethral strictures, severe phimosis and false passages. Intravaginal retraction of the urethral meatus can complicate Foley placement in postmenopausal females. In men, blind urethral procedures with mechanical or metal sounds without visual guidance or guidewire assistance are now discouraged due to the increased risk of urethral trauma and false passages. Newer techniques of urethral catheterization including guidewires, directed hydrophilic mechanical dilators, urethral balloon dilation, and direct vision endoscopic catheter systems are discussed, along with the new standardized protocol for difficult transurethral catheter insertions. Suprapubic catheter placement techniques, including percutaneous trocars and the use of the curved Lowsley tractor for initial suprapubic catheter insertion, are reviewed. Prevention and management of common catheter-related problems such as encrustation, leakage, Foley malposition, balloon cuffing and frequent blockages are discussed.

In Vitro Analysis of Balloon Cuffing Phenomenon

Aim: To investigates the different methods of balloon deflation, types of urinary catheters and exposure to urine media in catheter balloon cuffing. Materials and methods: Bardex®, Bard-Lubri-Sil®, Argyle®, Releen® and Biocath® were tested in sterile and E.Coli inoculated urine at 0, 14 and 28 days. Catheter deflation was performed with active deflation; passive deflation; passive auto-deflation; and excision of the balloon inflow channel. Balloon cuffing was assessed objectively by running the deflated balloon over a plate of agar and subjectively by 3 independent observers. Results: Bardex®, Argyle® and Biocath® showed greater degree of catheter balloon cuffing ( p < 0.01). Active balloon deflation was the worst method ( p < 0.01). The presence of infected urine media also contributed to greater balloon cuffing ( p > 0.05). Linear regression model analysis confirmed time as the most significant factor. Conclusion: The duration of catheters exposure, different deflation methods and types of catheters tested contributed significantly to catheter balloon cuffing ( p < 0.01).

Addressing the problems of long-term urethral catheterization: part 2

This is the second of a two-part article and addresses the problems encountered throughout the life of a catheter from those relating to its insertion, through the time when it is in situ, to those associated with its removal. Catheters can cause discomfort and reasons for this are discussed including latex allergy, atrophic changes in women, blockage or bypass. The draft National Institute for Health and Clinical Excellence infection control guidance is discussed with reference to catheter maintenance solutions. Sexuality can be an unvoiced concern to patients with catheters in situ and clinicians are encouraged to discuss such issues with the patient, where relevant. Issues including catheter expulsion, bladder spasm and difficulties in catheter removal, including the non-deflating balloon and cuffing are addressed. The article concludes that although every patient is an individual with a unique set of problems, learning how to address one series of difficulties will help when dealing with subsequent challenges.

Optimization of silicone urinary catheters for hypospadias repair

OBJECTIVE

We have experienced difficulty with the removal of all-silicone Foley catheters after hypospadias repair, relating to the formation of a 'cuff' of residual balloon material that fails to deflate, after aspiration of the instilled volume of water. This could potentially lead to both short- and long-term complications (stenosis, fistula). In all-silicone paediatric catheters, we investigated the production of such 'cuffs', and any other significant deformity which may be associated with deformation of the catheter balloon mechanism, in vitro.

MATERIALS AND METHODS

Catheters were inflated with 0 (control) to 7 mL of sterile water. The catheter balloon dimensions were measured before and after incubation of the catheters for 168 h in a solution simulating human urine. The aspiration volumes were recorded.

RESULTS

At volumes greater than 40% of the manufacturer's advised inflation volume, a significant increase in the transverse diameter of the catheter occurred after deflation, compared to controls (P<0.001).

CONCLUSION

We advise the maximum instillation of 2 mL of water into a 5-mL paediatric catheter balloon to avoid cuff formation. Using this technique allows all of the advantages of a stent, in combination with the security of a catheter, but with a reduced risk of trauma and complications associated with catheter removal.

An overview of suprapubic catheter care in community practice

This paper gives a broad overview of suprapubic catheterization. Community nurses can often feel they lack experience with suprapubic catheter general care and routine changes. This paper sets out the advantages and disadvantages of suprapubic catheters, the procedure for routine change and the golden rules for general care. The paper contains an introduction on trouble shooting.

Use of open-ended Foley catheter to treat profuse urine leakage around suprapubic catheter in a female patient with spina bifida who had undergone closure of urethra and suprapubic cystostomy: a case report

INTRODUCTION

Leakage of urine around a catheter is not uncommon in spinal cord injury patients, who have indwelling urethral catheter. Aetiological factors for leakage of urine around a catheter are bladder spasms, partial blockage of catheter, constipation, and urine infection. Usually, leakage of urine subsides when the underlying cause is treated. Leakage of urine around a suprapubic catheter is very rare and occurs in patients, in whom the urethra is closed due to severe stricture or previous surgery.

CASE PRESENTATION

We describe a 35-year-old female patient with spina bifida and paraplegia, who had undergone suprapubic cystotomy followed by urethral closure for leakage of urine per urethra. She developed leakage of urine around suprapubic Foley catheter, which did not subside even after changing the catheter, ruling out vesical calculus, and ensuring that there was no kink in catheter or drainage tube. As a desperate measure, we punched a large hole at the tip of a Foley catheter and used this catheter for suprapubic drainage. Leakage of urine around suprapubic catheter stopped and the patient was greatly relieved.

CONCLUSION

Leakage of urine around a catheter requires prompt attention in spinal cord injury patients; otherwise patients can develop maceration of neuropathic skin and pressure sore. Management of spinal cord injury patients with leakage of urine around a suprapubic catheter should include (i) changing the catheter, (ii) prescribing anticholinergic drugs to control bladder spasm, (iii) treating constipation and urine infection when present, (iv) imaging studies or flexible cystoscopy to look for vesical calculus. If leakage of urine persists despite all these measures, use of a modified Foley catheter in which, a large hole has been made at the tip, is worth trying.

Biofilm and other causes of pain in catheterization

This article looks at the anatomy of the bladder and how sensations, including pain, are transmitted to the brain. The use of urinary catheters is discussed and initially, the development of biofilm is addressed, from its cause, structure and effect, to how it can be treated. Many of the problems arising from biofilm and the resulting encrustation, can lead to pain, and the causes of this are discussed. Other problems which can cause patients to experience pain are also considered, and where there are possible solutions, these have been put forward. However, even when good practice is carried out, there will still be problems encountered, and further research is needed.

Causes and management of indwelling urinary catheter-related pain

Urinary catheters can be introduced into the urinary bladder either per urethra or via the suprapubic route; this article examines indications and contraindications to these routes. Catheter pain is subdivided into pain experienced as the catheter is passed, while in situ, and on removal. Relating to pain felt on insertion, risks associated with local anaesthetic/antiseptic gel and the occurrence of paraphimosis are discussed. Once in situ, the type of material used to manufacture the catheter, pressure on the urethra caused by a large Charrière size catheter, or from drainage bag traction, leading to discomfort and possible tissue damage are examined and solutions suggested. Catheter-associated meatal trauma in men and urethral post-menopausal discomfort in women are addressed; likewise, catheter cramp due to bladder spasm or catheter blockage, and interventions are recommended. Encrustation and 'cuffing' may cause pain during catheter removal and again, advice is given. Lastly, the possibility of pain due to fear/non-acceptance of the catheter is raised. In conclusion, once identified, the cause of catheter pain is often treatable, but should not be regarded negatively or ignored, as it warns of potentially harmful conditions and allows intervention before permanent damage can occur.

Determination of urethral catheter surface lubricity

Device for in-vitro measurement of static and kinetic friction coefficient of catheter surface was developed. Tribometer was designed and constructed to work with exchangeable counter-faces (polymers, tissue) and various types of tubes, in wet conditions in order to mimic in-vivo process. Thus seven commercially available urethral catheters, made from vinyl polymers, natural latex with silicone coating, all-silicone or hydrogel coated, and one made from polyvinylchloride with polyurethane/polyvinylpyrrolidone hydrogel coating obtained in our laboratory, were tested against three various counter faces: polymethacrylate (organic glass), inner part of porcine aorta and porcine bladder mucosa. Additionally, the hydrophility/hydrophobity of tested catheters was stated via water wetting contact angle measurement. Super-hydrophilic biomaterials revealed low friction on tissue and hydrophobic counter-face; slightly hydrophobic showed higher friction in both cases, while more hydrophobic manifested low friction on tissue but high on hydrophobic polymer. The smoothest friction characteristic was achieved in all cases on tissue counter-faces. The measured values of the static coefficient of friction of catheters on bladder mucosa counter-face were as follows: the highest (0.15) for vinyl and siliconised latex catheters and 3 folds lower (0.05) for all-silicone ones. Hydrogel coated catheters exhibited the lowest static and kinetic friction factors.

Urinary catheter use in older people

Long-term indwelling urinary catheters can be an effective means of managing bladder dysfunction for some older people, where alternative strategies are unsuitable or unsatisfactory, and where careful assessment of the patient and their particular problem has been undertaken. However, catheter-associated risks are well known and, consequently, catheters should be avoided wherever possible. Although prevalence of catheterization varies widely in different settings and different cultures of care, there is evidence that many older people are catheterized inappropriately and also remain catheterized unnecessarily. This paper discusses issues to be considered in decision-making processes regarding long-term catheterization. It examines catheter-associated problems, their management and factors influencing the quality of evidence to guide clinical practice.

An efficient solution to the retained Foley catheter

The most common cause of a retained Foley catheter is failure of the balloon to deflate. If noninvasive means are unsuccessful, balloon puncture is required. We present a safe and efficient technique using flexible video cystoscopy for balloon puncture and removal of any free fragments formed.

How to manage a urinary catheter balloon that will not deflate

On occasion, difficulty will be encountered removing an indwelling urethral catheter. This may be as a consequence of failure of the catheter balloon to deflate. This article reviews the published data on managing the non-deflating Foley catheter balloon, and suggests an evidence-based sequence of interventions to deflate the catheter balloon.

Kink, flow and retention properties of urinary catheters part 1: conventional foley catheters

The treatment for urinary incontinence, a common condition affecting a considerable number of older and disabled members of society, involves the use of a Foley catheter for drainage of the bladder. The basic design of the catheter has remained the same for over seventy years. Despite modifications to the materials used there has been very little research directly comparing the physical properties of the different types of catheter. This study developed a range of tests to enable comparison of the resistance to kinking, flow rate properties and the retention forces of both latex-based and all-silicone catheters. The results indicated that the all-silicone device had superior resistance to kinking and better flow properties when compared to the latex-based catheters. However, greater retention forces were recorded for the all-silicone device, in both the inflated and deflated condition, indicating that much more force would be required to remove the this type of catheter.

Removing indwelling catheters: trial without catheter in the community

Indwelling urinary catheters are inserted to drain the bladder for a variety of reasons, but are an intervention of last resort. Unless contraindicated, patients with an indwelling catheter should therefore have at least one trial without catheter to assess if they can pass urine without having a catheter in situ. The commonest method in undertaking trial without catheter is to remove a indwelling urethral catheter and monitor urinary output over a period of time. Another method is when the catheter is not removed in patients who have a suprapubic catheter. Instead the catheter is clamped, and urethral urine output monitored. This is followed by immediately measuring any residue of urine drained via the supra-pubic catheter. This article looks at undertaking a 'trial without catheter' using both methods and examines the arguments concerning when to remove catheters, midnight or early in the morning.

Suprapubic catheterization: challenges in changing catheters

Suprapubic catheterization of the bladder is used as a short- or long-term alternative to urethral catheterization. As with any indwelling urinary catheter, correct insertion, care and removal are vitally important to minimize problems. A particular problem that affects suprapubic catheters is 'cuffing', which on its own or combined with encrustation can potentially cause a great deal of difficulty on removal or discomfort for the patient. This article discusses the causes of cuffing, and suggests using catheters with integral balloons to reduce the incidence of the problem.

Laser division of encircling sutures to remove retained urethral catheter after radical retropubic prostatectomy

Inability to remove a urethral catheter after radical retropubic prostatectomy is an uncommon complication. We describe removal of a urethral catheter entrapped in vesicourethral anastomotic sutures, which was safely performed endoscopically using a holmium laser.

Clinical skills: how to remove and change a suprapubic catheter

Suprapubic catheterization is becoming more widely used to drain the urinary bladder either short or long term or is inserted where initial urethral or recatheterization is problematic. No matter where you work as a nurse, either in the hospital, community, hospice or nursing care home, sooner or later you will have to deal with a patient with a suprapubic catheter in situ. One of the concerns nurses encounter when changing the suprapubic catheter is what action to take when the catheter appears to have become stuck when removing it. The main cause of this problem is owing to a 'cuffing' effect occurring to the deflated catheter balloon, especially if using 100% silicone catheters. This article looks at the problem of removing a suprapubic catheter that has become stuck and how to change such catheters safely.

Fundamental principles of indwelling urinary catheter selection

Catheter selection is a skilled element of continence care, particularly when the catheter is intended to remain in situ for prolonged periods. It is important to choose carefully, referring to catheter length, material, Charrière size and balloon infill volume, any of which may--if not attended to correctly--cause problems. This article gives some advice on catheter selection and outlines what may occur if certain issues are dealt with incorrectly.

Suprapubic catheter removal: the cuffing effect of deflated catheter balloons

Supra-pubic catheterization plays an important role in patient care and management when this method of indwelling catheterization is required. However, one area of concern often experienced by nurses is the problem removing supra-pubic catheters or not being able to remove it. Catheter balloons, when deflated, incur crease or ridge formation. Removing supra-pubic catheters, a 'cuffing' effect occurs as the catheter is being removed. This seems to affect 100% silicone catheters more than non-silicone catheters. This article looks at the changes 100% silicone catheter balloons undergo following deflation and removal.