Douglas F. Milam

Urological Manifestations of Sacrococcygeal Teratoma

A review was done of 29 patients diagnosed with sacrococcygeal teratoma between 1978 and 1991. Urological disorders included total urinary retention (6 patients), hydronephrosis (6), hydrocele (4) and undescended testis (1). Ultrasonography and voiding cystourethrography were performed on the 6 patients in total urinary retention. These studies revealed cystic retrorectal lesions frequently with intralesional calcifications, and anterior and superior displacement of the bladder. Bladder wall trabeculation occurred in 2 of these 6 patients, and 4 had moderate or severe hydronephrosis. Upper urinary tract dilatation was found in 2 patients not in total retention. Hydronephrosis appeared to be related to poor bladder emptying and presumably high intravesical pressures, since each case resolved spontaneously after tumor resection. No primary upper tract anomalies were identified.

An update on the use of transdermal oxybutynin in the management of overactive bladder disorder

Antimuscarinic medications are used to treat nonneurogenic overactive bladder refractory to nonpharmacologic therapy. Side effects such as dry mouth, constipation, blurred vision, dizziness, and impaired cognition limit the tolerability of therapy and are largely responsible for high discontinuation rates. Oxybutynin is a potent muscarinic receptor antagonist whose primary metabolite after first-pass hepatic metabolism is considered largely responsible for its associated anticholinergic side effects. Transdermal administration of medications bypasses hepatic processing. Specifically with oxybutynin, whose low molecular weight permits transdermal administration, bioavailability of the parent drug with oral administration is less than 10%, whereas with transdermal delivery is a minimum of 80%. The result has been an improved side effect profile in multiple clinical trials with maintained efficacy relative to placebo; however, the drug may still be discontinued by patients due to anticholinergic side effects and application site reactions. Transdermal oxybutynin is available as a patch that is changed every 3–4 days, a gel available in individual sachets, or via a metered-dose pump that is applied daily. The transdermal patch was briefly available as an over-the-counter medication for adult women, although at this time all transdermal formulations are available by prescription only.

Overactive bladder and autonomic dysfunction: Lower urinary tract symptoms in females with postural tachycardia syndrome.

Postural Tachycardia Syndrome (POTS) represents an autonomic disorder predominantly affecting females between 15 and 50 years of age. POTS is a chronic disorder (>6 months) characterized by an excessive heart rate increment on standing (>30 beats/min) in the presence of characteristic symptoms of cerebral hypoperfusion or sympathetic activation. Patients have clinically been noted to describe lower urinary tract symptoms (LUTS), although urologic symptoms have not been methodically assessed in the POTS population. Herein, we present data from a pilot study designed to identify and quantitate overactive bladder (OAB) in patients diagnosed with POTS.

Effect of thermal changes on optical properties in fresh and previously frozen prostate tissue

The deposition, and distribution of light in laser irradiated tissue are important in determining the extent of tissue injury during laser prostatectomy. As tissue is irradiated, the optical properties change as a function of temperature due to an alteration of molecular and cellular structure. An increase in the absorption or scattering coefficient may prevent light from penetrating deeper into tissue, thus compromising laser treatment. The purpose of this study was to determine if temperature affects the optical scattering and absorption coefficients of canine prostate tissue. The effects of freezing of tissue prior to measurement were also investigated. A double integrating sphere spectrophotometer was used to measure reflectance, and transmittance of laser light in canine prostate at two wavelengths. Optical properties were calculated using an inverse adding-doubling algorithm. Measurements were made on samples heated for ten minutes in a waterbath at 10 degree increments from 35 to 55 degrees Celsius, and 5 degree increments from 60 to 85 degrees Celsius. In general, absorption and anisotropy coefficients decreased slightly with increasing exposure temperature up to 65 degrees Celsius, then increased sharply. Scattering coefficients increased slowly from the baseline temperature to 60 degrees Celsius, followed by a sharp increase between 60 and 70 degrees Celsius. The scattering coefficient appeared to decrease at higher temperatures. Freezing the tissue prior to making the measurements resulted in a higher estimate of (mu) a, (mu) s, and g. These results were also found to be dependent upon the wavelength investigated. Results from this study indicate that as tissue is coagulated, thermally induced changes in the optical properties will limit the depth of penetration of light into the tissue.

Finite element modeling of heat transfer in the prostate

Laser prostatectomy is an alternative to conventional surgical resection. However, clinical studies lack sufficient power to determine optimal exposure parameters. This paper describes axi-symmetric and 3D finite element models of heat transport in laser irradiated tissue. These models have been verified with an analytical solution for a laser with a Gaussian beam profile using both stationary, and scanning laser beams. Percent errors between the analytical solutions and the finite elements solutions were less than 7%. Further development of these models will facilitate optimization of laser prostatectomy methods.

Male Erectile Dysfunction

Publisher Summary This chapter focuses on male erectile dysfunction, its etiology, and the mechanism involved in erection. Sexual dysfunction is a common, almost expected, consequence of autonomic dysfunction. Sexual dysfunction may present with decreased erectile rigidity in the man, decreased libido, absent or delayed orgasm in either sex, or rapid ejaculation. Sexual thoughts from the cerebral cortex, nocturnal cortical stimuli during REM sleep, and tactile sexual stimulation may trigger penile erection. Cortical areas involved in sexual function include the medial preoptic area, medial amygdala, paraventricular nucleus, periaqueductal gray, and the ventral tegmentum. Sexual stimulation causes release into the cavernous neuromuscular junction of a number of neurotransmitters from cholinergic parasympathetic and nonadrenergic noncholinergic (NANC) fibers. The anatomical site felt to be the most common cause of erectile dysfunction in the general population is the neuromuscular junction where the NANC nerves meet the smooth muscle and vascular endothelium of the deep cavernous penile arteries. Pure neurogenic erectile dysfunction is a frequent cause of erectile failure. Interruption of either somatic or autonomic nerves or their end units may cause erectile dysfunction.

96 – Male Erectile Dysfunction

Publisher Summary Individuals with autonomic dysfunction are markedly more prone to develop impotence or erectile dysfunction (ED) than those without autonomic dysfunction. The anatomic site currently believed to be the most common cause of ED is the neuromuscular junction where the cavernosal nerves meet the smooth muscle of the deep cavernous penile arteries. Neurologic diseases can also produce discrete lesions in central or peripheral nerves that cause ED. The most common endocrine disorder affecting erectile ability is diabetes mellitus. Erection is partially mediated by efferent parasympathetic cholinergic neural stimuli. Loss of long cholinergic neurons results in interruption of the efferent side of the erectile reflex arc. Effective oral medical therapy has changed the work-up and treatment of ED. Diagnostic tests—such as plasma testosterone—are often deferred to medical therapy failures if the patient has normal libido, no gynecomastia, and testes of normal size and consistency. Other therapeutic interventions, including pharmacologic injection of prostaglandin E1, intraurethral delivery of prostaglandin E1, vacuum erection devices, and inflatable penile implants produce excellent results in selected patients.

Impotence: Diagnosis and Management of Erectile Dysfunction

ABSTRACT The book Impotence, edited by Alan Bennett, is an important resource for persons treating patients with erectile dysfunction. While it was principally written for urologists, other specialists will find useful information in this very readable book. Chapter authors are experts in their fields.Six early chapters are devoted to epidemiology, anatomy, physiology, endocrine factors, pharmacology, and the diagnostic workup of erectile dysfunction. Practical patient care issues were clearly the editors primary focus. As such, anatomy and physiology necessary for understanding the diagnostic and treatment rationale are stressed. Those looking for substantial depth on important yet esoteric subjects such as endothelium-derived relaxing factor (nitric oxide) will have to look elsewhere.Impotence is a common disorder estimated to affect 10 million American men. Both prevalence and severity increase with advancing age. One study is cited in which 25%, 55%, and 75% of 65-, 75-, and 80-year-old men, respectively, were found to be