A new temporary catheter (ContiCath) for the treatment of temporary, reversible, postoperative urinary retention

Critical appraisal of the Spanner™ prostatic stent in the treatment of prostatic obstruction

The Spanner™ stent was first used in patients to relieve bladder outlet obstruction (BOO), and has recently been used in patients following transurethral microwave thermotherapy and men unfit for surgical intervention. We review the current literature on the role of the Spanner stent in treating prostatic obstruction compared to previously reported cases involving the use of temporary stents. The Spanner stent has been found to be successful in treating patients with bladder outlet obstruction from benign prostatic hyperplasia and following high-energy transurethral microwave thermotherapy (TUMT). Patients with the Spanner stent had an increase in peak flow rate and a decrease in post void residual and International Prostate Symptom Scores. In patients treated with TUMT, quality of life measures indicate that the Spanner stent shows increased ease of bladder drainage, decreased leakage, and no adverse effect on daily activities. In patients unfit for surgery, however, there was increased retention and pain requiring stent removal in 63% of cases. The Spanner stent offers ease of insertion with a decrease in voiding symptoms in selected patients. Based on limited data, the Spanner stent has been recommended as a treatment option for men with BOO following TUMT. However, it is not a good treatment option for men unfit for surgery based on an increased incidence of urinary retention and dysuria. The Spanner stent is the only currently approved temporary stent and, based on a literature review, it does not offer significant advantage over previously used temporary stents. It is notable that most researchers have not evaluated the role of detrusor function on the outcomes.

Spinal hyperexcitability and bladder hyperreflexia during reversible frontal cortical inactivation induced by low-frequency electrical stimulation in the cat

Spinal hyperexcitability and hyperreflexia gradually develop in the majority of stroke patients. These pathologies develop as a result of reduced cortical modulation of spinal reflexes, mediated largely indirectly via relays in the brainstem and other subcortical structures. Cortical control of spinal reflexes is markedly different in small animals, such as rodents, while in some larger species, such as cats, it is more comparable to that in humans. In this study, we developed a novel model of stroke in the cat, with controllable and reversible inhibition of cortical neuronal activity appearing approximately 1h after initiation of low-frequency electrical stimulation in the frontal cerebral cortex, evidenced by a large increase in the alpha frequency band (7-14 Hz) of the frontal electrocorticographic signal. Hyperreflexia of the urinary bladder developed 3h or more after induction of reversible cortical inactivation with optimized stimulation parameters (frequency of 1-2 Hz, amplitude of 10 mA, applied for 30 min). The bladder hyperreflexia persisted for at least 8h, and disappeared within 24h. At the S2 level of the spinal cord, where neural circuits mediating micturition and other pelvic reflexes reside, we have recorded an increase in neuronal activity correlated with the development of hyperreflexia. The low-frequency stimulation-induced reversible cortical inactivation model of stroke is highly reproducible and allows evaluation of spinal hyperexcitability and hyperreflexia using within-animal comparisons across experimental conditions, which can be of great value in examination of mechanisms of spinal hyperreflexia following stroke or brain trauma, and for developing more effective treatments for these conditions.

The Bell-Shaped Nitinol Prostatic Stent in the Treatment of Lower Urinary Tract Symptoms: Experience in 108 Patients

OBJECTIVES

To assess the efficacy, safety, and durability of the bell-shaped nitinol prostatic stent in the treatment of moderate to severe lower urinary tract symptoms caused by benign prostatic enlargement in otherwise healthy patients.

METHODS

Stents were inserted in an outpatient setting under local anaesthesia. Assessments included maximum urinary flow (Qmax), postvoid residual (PVR) urine volume, International Prostate Symptom Score (IPSS), including quality of life (QoL) item, at baseline and follow-up visits.

RESULTS

108 men were enrolled in the trial. Stents were successfully inserted in 97% of the patients. Spontaneous voiding was achieved in all patients. After one month Qmax (+3.7 ml/s), PVR (-99 ml), IPSS (-12) and QoL (-1.7) all showed statistically significant improvements compared to baseline. Substantial improvements, however, were maintained for only one to two months. The main complications were haematuria (19%), urge incontinence (22%), and migration (15%). The median indwelling time was 105 days. The main reason for removal of stents was worsening of symptoms, which might be attributable to the tilting of stents within the prostatic urethra, found upon removal.

CONCLUSIONS

Insertion of the bell-shaped nitinol prostatic stent temporarily improves voiding parameters and symptom scores. Because of the limited durability, however, the bell-shaped prostatic stent is not suitable for clinical practice.

In vitro bactericidal effect of a modified thermal Nitinol electrode

PURPOSE

A standard electrode surgical generator connected to a Nitinol coil was used in vitro to evaluate whether the generated electromagnetic energy had any bactericidal effect on Escherichia coli.

MATERIALS AND METHODS

The ATCC 259222 E. coli strain was used. We mixed 135 mL of a 1.5% non-nutritive agar with 15 mL of a 10(6) CFU/mL inoculum and transferred it to gas-sterilized plastic containers lined with aluminium foil. A 22F cylindrical shape was cut from the center of the agar, and a Nitinol coil was placed in that space and connected to a standard electrode surgical generator. Electrical energy was then applied from 5 to 25 V at 5-V increments. Temperatures were measured with two thermocouples placed in the middle and periphery of each agar. The treatment was stopped when the temperature at the middle thermometer reached 50 degrees C. The control group was not treated and was embedded in a water bath at 45 degrees C. Three 3 x 7-mm pieces were sliced from the inner to the outer part of the agar and processed, and colony counts were performed.

RESULTS

We observed statistically significant deleterious effects on E. coli in all three zones when the treatment voltage was 15 and 20. When the potential was raised to 25 V, we observed a significant result only in the core zone. The treatment duration was 50 minutes for 5 and 10 V, 45 minutes for 15 V, 15 minutes for 20 V, and 10 minutes for 25 V.

CONCLUSION

The bactericidal effect was mainly in the central area, decreasing linearly toward the periphery, and was related to the temperature reached during activation of the electrical generator. These results were disappointing with regard to the utility of Nitinol stents to treat bacterial prostatitis.

Voiding and sexual dysfunction after cerebrovascular accidents

PURPOSE

We provide an up-to-date review of the urological manifestations of cerebrovascular accidents and their management, including sexual manifestations.

MATERIALS AND METHODS

We performed a comprehensive MEDLINE search for peer reviewed articles using key words and incorporated these data with our experience with the treatment of patients in an acute stroke unit, rehabilitation unit and ambulatory care center.

RESULTS

The knowledge of urological dysfunction after stroke is based largely on the evaluation of symptomatic patients. The predominant symptoms are urinary frequency, urgency and urge incontinence. Time after stroke has a significant influence on urological findings. Detrusor hyperreflexia is the most common urodynamic finding. Whereas the site and size of the stroke clearly have an influence on urological findings, to our knowledge the effect of the involved hemisphere is unclear. Urinary incontinence as an initial presentation in acute stroke is associated with a high mortality rate. Sexual dysfunction is common in men and women. Co-morbid conditions, such as diabetes mellitus, benign prostatic hyperplasia and urethral incontinence, may complicate evaluation and management.

CONCLUSIONS

A stroke has a profound effect on lower urinary tract function, sometimes resulting in significant morbidity. In well rehabilitated patients sexual dysfunction should be assessed and treatment may be considered to improve quality of life with safety. An overall conservative approach to management is recommended in the initial 3 to 6 months since improvement is common with time.

Do prostatic stents solve the problem of retention after transurethral microwave thermotherapy?

Temporary nonmetallic stents offer an alternative to an indwelling catheter for the management of voiding problems after heat-based therapies for benign prostatic hyperplasia. Patient comfort is improved, and they are able to void immediately after the procedure. Unlike a catheter, stents function on the principle of active drainage. Thus, a functioning detrusor muscle is imperative for stent success. Single-center clinical trials have reported encouraging results; however, predictable success criteria are yet to be established. Multicenter trial data are awaited.

Endoprostatic stents for management of benign prostatic hyperplasia

Endoprostatic stents have been developed for relieving bladder outlet obstruction secondary to benign hyperplasia of the prostate. The stents are designed either for permanent or for temporary placement. The short-term temporary stents of various biostable and biodegradable polymers are needed after minimally invasive therapy of prostate with heat. The temporary stents are a management option, whereas the permanent stents are a treatment option. Permanent stents offer immediate relief and their sustained results for 4-7 years make them ideally suited for medically compromised patients.