Rezum for retention-retrospective review of water vaporization therapy in the management of urinary retention in men with benign prostatic hyperplasia.

OBJECTIVE: Rezum vapor ablation is a minimally invasive treatment for benign prostatic hyperplasia (BPH) that uses injections of sterile water vapor directly into the prostate for tissue ablation. Although Rezum is currently indicated for use in men with prostate sizes ≥30 and ≤80 ml, it is unclear how effective Rezum is for men in urinary retention. We sought to determine whether Rezum is effective in the treatment of catheter-dependent urinary retention secondary to BPH. METHODS: A retrospective chart review was conducted on consecutive patients who presented for urinary retention and subsequently treated with Rezum. We evaluated procedural details and examined variables pre- and post-Rezum (at 6 months) including International Prostate Symptom Score (IPSS), IPSS quality of life (IPSS-QOL), maximum flow (Qmax ), post void residual volume (PVR), prostate specific antigen, rate of retention, and use of alpha blockers and 5-alpha reductase inhibitor (5ARI). RESULTS: Of the 49 patients included in this study, median age of was 73 years, median prostate volume was 73cc (Interquartile range [IQR]: 50, 103) and a median lobe was present in 80% of patients. All patients were in urinary retention before treatment with a median PVR of 900 ml (IQR: 566, 1146). Following Rezum, IPSS (17 pre-Rezum, 4 post-Rezum) and IPSS-QOL (4 pre-Rezum, 1 post-Rezum) both improved at 6 months (p < 0.01). Qmax increased from 3 to 6 ml/s (p = 0.03) and PVR decreased from 900 to 78 ml (p < 0.01). Only 17/38 patients taking alpha-blockers and 7/15 patients on 5ARIs continued therapy at 6 months following Rezum (p < 0.01). Of the 49 patients treated, 10 (20.4%) remained in catheter dependent urinary retention following the procedure, and 6 remained in retention at 6 months (12.2%) even after further surgical therapies for BPH (p < 0.01). CONCLUSION: Rezum is a safe and effective therapy for treating catheter dependent urinary retention in patients with BPH, including those with median lobes. As a minimally invasive therapy, it is a promising option in patient, particularly those who are not suitable for prolonged anesthesia.

Perturbative theory for Brownian vortexes.

Brownian vortexes are stochastic machines that use static nonconservative force fields to bias random thermal fluctuations into steadily circulating currents. The archetype for this class of systems is a colloidal sphere in an optical tweezer. Trapped near the focus of a strongly converging beam of light, the particle is displaced by random thermal kicks into the nonconservative part of the optical force field arising from radiation pressure, which then biases its diffusion. Assuming the particle remains localized within the trap, its time-averaged trajectory traces out a toroidal vortex. Unlike trivial Brownian vortexes, such as the biased Brownian pendulum, which circulate preferentially in the direction of the bias, the general Brownian vortex can change direction and even topology in response to temperature changes. Here we introduce a theory based on a perturbative expansion of the Fokker-Planck equation for weak nonconservative driving. The first-order solution takes the form of a modified Boltzmann relation and accounts for the rich phenomenology observed in experiments on micrometer-scale colloidal spheres in optical tweezers.

Modern technique for penile torsion repair.

PURPOSE: Penile torsion is a congenital malformation that results in a rotational defect of the penile shaft. Various techniques have been described for correcting penile torsion, although there is no consensus on the best repair. We describe our experience using a dorsal dartos flap to correct penile torsion. MATERIALS AND METHODS: We retrospectively reviewed the records of all 25 patients who underwent repair of significant penile torsion using a dorsal dartos flap at our institution between 2004 and 2007. A total of 17 repairs were performed in association with chordee repair, 7 with hypospadias and 1 with bilateral inguinal hernias. Patient age at the time of repair ranged from 6 to 19 months (mean 9). Of the patients 15 had torsion of at least 90 degrees, 8 had torsion of 60 to 90 degrees and 2 had torsion that was not recorded in degrees. RESULTS: Mean followup was 4 months (range 1.5 to 19). Of the cases 16 demonstrated complete resolution of penile torsion, 7 had residual torsion less than 10 degrees and 2 had documented improvement that was not reported in degrees. No patient has undergone further repair for torsion. CONCLUSIONS: Penile torsion is a challenging congenital anomaly. The dorsal dartos flap is familiar to pediatric urologists and can be varied for use in repair of penile torsion. The procedure results in successful repair of the torsion, has few complications and can easily be performed concurrently in the setting of other operative repairs. This approach provides excellent short-term results.

Use of anticholinergic therapy in men.

Lower urinary tract symptoms in men usually include symptoms of bladder overactivity such as urinary frequency, urgency or nocturia. These are often the initial presenting symptoms for men seeking medical attention for urinary dysfunction. The prevalence of overactive bladder in men is similar to women and increases with advancing age. While women with these symptoms are treated primarily with anticholinergic therapy, there is reluctance to use these agents in men due to concerns regarding worsening obstructive symptoms or urinary retention exacerbated by a large prostate. For men, alpha blocker monotherapy remains the primary therapy for lower urinary tract symptoms despite the fact that a larger fraction of men continue to experience symptoms of overactive bladder. There is emerging body of evidence that the use of anticholinergic agents may be safe and effective in men. We will discuss the rationale for the use of anticholinergic therapy in men with bladder overactivity, either alone, or in combination with alpha blockers. We will review the current literature on the topic and discuss potential future directions in the management of overactive bladder in men.

Phenytoin metabolite renal calculus: an index case.

INTRODUCTION: Drugs and their metabolites are known factors in 1% to 2% of all kidney stones. Certain antiepileptic drugs are known to cause stone formation. Phenytoin is used as a first line antiepileptic therapy for many seizure disorders. We present what we believe to be the first report of a phenytoin metabolite urinary stone. METHODS: A 79-year-old woman with a fever and seizure disorder was found to have a right pelvic kidney with hydronephrosis and multiple large calcifications. She had been taking the antiepileptic medication phenytoin for the past 10 years. Average total serum phenytoin level from the year prior was in the normal range. Free phenytoin levels were not routinely monitored, but the one value available was elevated at 5.1 ng/dL. The patient underwent a percutaneous nephrolitomy, ultimately expiring from medical complications after the procedure. Final stone analysis revealed a composition of 35% phenytoin metabolite (5-(para-hydroxyphenyl)-5-phenylhydantoin) and 65% proteinaceous material. An extensive review of literature including PubMed, MedLine, and various internet search engines was performed, searching for any prior reports of urinary calculi formed from phenytoin or its metabolite. RESULTS: No previous reports of phenytoin or phenytoin metabolite urinary stones were found in the medical literature. Phenytoin has many known ill effects on the genitourinary system including acute interstitial nephritis, nephrotic syndrome, acute renal failure, and priapism. Now we can add urinary lithiasis to the list of its potential adverse effects. This article represents the first report of a phenytoin metabolite urinary stone. CONCLUSION: A metabolite of the commonly used antiepileptic medication phenytoin can cause clinically relevant urolithiasis leading to significant morbidity and even mortality. Clinicians should have an increased level of suspicion for metabolite stone formation in symptomatic patients taking antiepileptic medications. Further studies on phenytoin metabolism and its potential for inducing urinary lithiasis should be performed.

New developments in the diagnosis and management of pediatric UTIs.

Urinary tract infections (UTIs) in children are common and a major source of morbidity. The incidence of UTIs in childhood is not precisely known because it is not a reportable disease, and in many cases, especially in infants, UTIs are underdiagnosed. Furthermore, the definitions and criteria for diagnosis vary considerably. This article reviews the diagnosis and work-up of UTIs in children, and presents current data reviewing the roles of radiologic imaging, surgical correction, and antibiotic prophylaxis in the setting of pediatric UTIs.

Spatial transformations in the withdrawal response of the tail in intact and spinalized rats.

Previous studies of spatial transformations between sensory input and motor output in escape responses have suggested two alternative patterns of spatial integration. The continuous pattern corresponds to withdrawal movements directed 180 degrees away from the location of the stimulus, whereas the categorical pattern corresponds to movements that are biased toward a limited number of preferred directions. The goal of these experiments was to determine which pattern best describes the tail withdrawal response in spinalized and intact rats by applying pinpoint heat stimuli at eight points distributed circumferentially around the tail and measuring the direction and speed of the resulting withdrawal response. Our results are consistent with a novel, hybrid continuous-categorical movement strategy. In the spinalized animal, responses were primarily away from the stimulus (the continuous component) but exhibited a pronounced ventral bias (the categorical component). In addition, stimuli delivered to the ventral surface, which would be expected to evoke a dorsally directed response (opposite to the preferred ventral direction), instead evoked responses that were markedly variable and clustered in the left and right directions. Intact rats showed a similar pattern of response, except reversed; the bias was in the dorsal direction, and the response to dorsal stimulation was now highly variable and lateral in direction. These results reveal a complex tail withdrawal strategy that is modulated by descending supraspinal pathways to adapt the response to the biomechanical and environmental constraints imposed on movement of the rat tail.