E. J. G. Milroy

A NEW TREATMENT FOR URETHRAL STRICTURES

A urethral stent, originally developed for endovascular use, was implanted into eight patients with urethral strictures after experimental studies in the canine urethra. The stent is woven in the form of a tubular mesh from surgical grade stainless steel wire and is self-expanding when released from its small-diameter delivery catheter. At follow-up 6 months to 1 year postoperatively (mean 8 months) all had a good calibre urethra. Urethroscopy showed complete epithelial covering of the implant at 4-6 months.

ROLE OF SUBCUTANEOUS APOMORPHINE IN PARKINSONIAN VOIDING DYSFUNCTION

Ten patients with Parkinsons disease and urinary symptoms underwent urodynamic assessments before and after subcutaneous administration of the dopamine receptor agonist apomorphine. Voiding efficiency improved after apomorphine injection, with an increase in mean and maximum flow rates in nine patients and reduction in post-micturition residual volume in six. Although the effect on detrusor behaviour was variable, subcutaneous apomorphine may be of use in both the assessment and treatment of voiding dysfunction in patients with Parkinsons disease.

Nerve fibre proliferation in interstitial cystitis

The aetiology of pain in interstitial cystitis is not understood, although it has been reported to be due to release of mediators from mast cell granules. Cystolysis and intravesical instillation of dimethyl sulphoxide have been shown to relieve pain in this condition. We have studied the nerve population within the bladder wall using immunohistochemical stains for protein gene product 9.5. A group of 18 cases of chronic interstitial cystitis and 12 controls; neuropathic bladder (n=1), chronic bacterial cystitis (n=3), systemic lupus erythematosus cystitis (n=2) and normals (n=6), were investigated. There were significantly more nerve fibres within the sub-urothelial and detrusor muscle layers in chronic interstitial cystitis than there were in normals. Patients with chronic cystitis of other aetiology did not have a significant increase in nerve fibre density within the bladder wall suggesting a specific association between nerve fibre proliferation and interstitial cystitis. Cystolysis is shown to deplete selectively the submucosal nerve plexuses without altering the nerve density within detrusor muscle. This finding explains the desensitisation of the bladder without impairment of detrusor function after this procedure.

Autoradiographic analysis of alpha-adrenoceptors and muscarinic cholinergic receptors in the hyperplastic human prostate

Radioligand receptor binding and autoradiography were used to characterize, localize and compare alpha-1 and alpha-2 adrenoceptors and muscarinic cholinergic receptor populations in human benign prostatic hyperplastic tissue. The binding of selective alpha-1 and alpha-2 ligands, [3H]-prazosin and [3H]-UK 14,304, to homogenates of human central and peripheral prostate was saturable and of high affinity. Scatchard analysis produced an equilibrium dissociation constant (KD) of 0.51 +/- 0.10 nM for alpha-1 adrenoceptors, and 2.34 +/- 0.40 nM for alpha-2 adrenoceptors. The mean densities, Bmax, of alpha-1 and alpha-2 adrenoceptors identified in the human adenomatous prostate were 65.9 +/- 12.9 and 36.1 +/- 7.0 fmoles/mg. protein respectively. Receptor autoradiography was used to examine the distribution of muscarinic cholinergic receptors [( 3H]-QNB), alpha-1 adrenoceptors [( 3H]-prazosin]), and alpha-2 adrenoceptors [( 3H]-rauwolscine) on consecutive sections of benign hyperplastic prostatic tissue. Although both subtypes of adrenoceptor were seen in the stromal component of the hyperplastic prostate, there was a substantial predominance of alpha-1 adrenoceptors. A densitometric computer-assisted analysis was performed on the autoradiographic slides to determine the mean ratio of specific alpha-1: alpha-2 adrenoceptors in the stromal compartment of the hyperplastic tissue. The ratio, expressed as % grain occupancy/unit area, was 3.9 +/- 0.75, which is in agreement with a functional alpha-1 adrenoceptor predominance shown in previous studies. Although sparsely distributed in the stroma, a dense alpha-2 adrenoceptor population was seen in association with blood vessels, and in close proximity to the base of some of the [3H]-QNB-labelled prostatic glandular epithelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-Term Results of Urolume Urethral Stent for Recurrent Urethral Strictures

PURPOSE We present the long-term results of the first 50 patients treated with a new urethral stent (UroLume) developed in 1985 for recurrent bulbomembranous urethral strictures. MATERIALS AND METHODS All stents were inserted with the patient under general anesthesia using a standard endoscopic delivery system. Of the patients 27 were followed for 5 years or longer, 5 for 4 years and 18 for shorter periods due to death, illness or other factors. RESULTS Mean (plus or minus standard deviation) maximum flow rate at last following was 19.7 ml. per second (+/- 6.9), and 93% of the patients were satisfied with the stent. In 8 patients (16%) narrowing developed within the lumen of the stent and in the remaining 84% the stent achieved its purpose of maintaining a good urethral lumen. In 9 patients stricture recurred outside the stent because of inaccurate positioning. All of these complications were satisfactorily treated by an additional overlapping stent. Failures occurred particularly in patients with a long stricture history and extensive periurethral fibrosis. CONCLUSIONS These results indicate that at 4 to 6 years promising early results with the UroLume stent for urethral strictures are maintained with a low late failure rate. This device is not suitable for all strictures and cases with extensive periurethral fibrosis should be avoided but it remains a useful and successful treatment option for many recurrent bulbomembranous urethral strictures.

A new treatment for urethral strictures: a permanently implanted urethral stent

We describe a new urethral stent, originally developed for endovascular use, that we have implanted into 8 patients with urethral strictures. The stent is woven in the form of a tubular mesh from surgical grade stainless steel wire and is self-expanding when released from its small diameter delivery catheter. All patients have been treated successfully with a good caliber urethra visible on urethrography and direct endoscopy, and with improved urine flow rates. Mean followup of these patients is 8 months (range 6 months to 1 year). Urethroscopy had demonstrated complete epithelial covering of the implant at 4 to 6 months. Although the followup is short it seems that this simple technique may offer a lasting treatment for many urethral strictures.

The Urolume Stent in the Management of Benign Prostatic Hyperplasia

There were 54 patients entered into this study of the UroLume permanent prostatic stent, most of whom were unfit for conventional prostatic surgery. The stents were inserted with the patient under local or regional anesthesia. Of the patients 34 presented in acute retention, 12 had chronic retention, 4 had severe and worsening symptoms, and 4 had symptoms and urodynamic evidence of obstruction occurring in the presence of Parkinsons disease. Following stent insertion 50 patients were able to void satisfactorily, while the remaining 4 presented with chronic retention and detrusor failure. The 40 patients who had no or minimal remaining symptoms were satisfied with the stent. Most patients experienced frequency and urgency of micturition for 1 to 3 months, which resolved in all but 9 patients with persistent severe detrusor instability. Symptom scores decreased to 6.5 (total) at 1 year for nonretention patients and 6.0 for retention patients. Stents were covered with epithelium within 6 to 9 months. However, when the stent was positioned with any part of the proximal end within the bladder or when the stent could not be epithelialized incrustation occurred (14 cases, all of which were asymptomatic). No serious urosepsis was noted in any patient in this study. Six stents were removed endoscopically without difficulty or damage to the urethra at up to 18 months. The implications of these findings to the potential role of the UroLume stent in the management of a wider range of patients with prostatic obstruction are discussed.

An Increase of Neuropeptide Y But Not Nitric Oxide Synthase-Immunoreactive Nerves in the Bladder Neck from Male Patients with Bladder Neck Dyssynergia

PURPOSE To determine the distribution of neuropeptides in male patients with bladder neck dyssynergia and benign prostatic hyperplasia. MATERIALS AND METHODS Bladder neck tissue, obtained from male patients with bladder neck dyssynergia (BND) and control patients with benign prostatic hyperplasia (BPH), was studied immunohistochemically for protein gene product 9.5 (a general neuronal marker), vasoactive intestinal polypeptide, neuropeptide Y, calcitonin gene-related peptide, substance P, growth associated protein 43 and nitric oxide synthase. RESULTS In the bladder neck from control patients, the greatest density of nerves contained protein gene product 9.5, followed in decreasing order by neuropeptide Y; vasoactive intestinal polypeptide; calcitonin gene-related peptide; nitric oxide synthase; substance P and serotonin. The neuropeptides were found in the smooth muscle and were also associated with blood vessels. In patients with BND there was a statistically significant increase (P < 0.05) in the density of protein gene product 9.5- and neuropeptide Y-immunoreactive nerves in the smooth muscle and the base of the mucosa but not in blood vessels in the bladder neck, while the density of the other neuropeptides studied, nitric oxide synthase and serotonin did not significantly change from that of control tissue. Growth associated protein 43-immunoreactive nerves were absent from the bladder neck from both groups of patients. CONCLUSION It is suggested that the increase in density of protein gene product 9.5- and neuropeptide Y-immunoreactive nerves, part of the sympathetic contractile system of the bladder neck, may exacerbate bladder outlet obstruction and thus play a role in the pathogenesis of BND.

Haemodynamic evidence for cardiac stress during transurethral prostatectomy.

OBJECTIVE--To compare haemodynamic performance during transurethral prostatectomy and non-endoscopic control procedures similar in duration and surgical trauma. DESIGN--Controlled comparative study. SETTING--London teaching hospital. PATIENTS--33 men aged 50-85 years in American Society of Anesthesiologists risk groups I and II undergoing transurethral prostatectomy (20), herniorrhaphy (eight), or testicular exploration (five). MAIN OUTCOME MEASURES--Percentage change from baseline in mean arterial pressure, heart rate, Doppler indices of stroke volume and cardiac output, and index of systemic vascular resistance, and change from baseline in core temperature. RESULTS--In the control group mean arterial pressure fell to 11% (95% confidence interval -17% to -5%) below baseline at two minutes into surgery and remained below baseline; there were no other overall changes in haemodynamic variables and the core temperature was stable. During transurethral prostatectomy mean arterial pressure increased by 16% (5% to 27%) at the two minute recording and remained raised throughout. Bradycardia reached -7% (-14% to 1%) by the end of the procedure. Doppler indices of stroke volume fell progressively to 15% (-24% to -6%) below baseline at the end of the procedure, and the index of cardiac output fell to 21% (-32% to -10%) below baseline by the end of the procedure. The index of systemic vascular resistance was increased by 28% (17% to 38%) at two minutes, and by 46.8% (28% to 66%) at the end of the procedure. Core temperature fell by a mean of 0.8 (-1.0 to -0.6) degrees C. Significant differences existed between the two groups in summary measures of mean arterial pressure (p less than 0.05), Doppler indices of stroke volume (p less than 0.005) and cardiac output (p less than 0.005), index of systemic vascular resistance (p less than 0.0005), and core temperature (p less than 0.0001). CONCLUSIONS--Important haemodynamic disturbances were identified during routine apparently uneventful transurethral prostatectomy but not during control procedures. These responses may be related to the rapid central cooling observed during transurethral prostatectomy and require further study.

Cardiovascular Performance and Core Temperature During Transurethral Prostatectomy

Hemodynamic performance and core temperature were recorded during transurethral prostatectomy in 52 patients who were stratified according to cardiac symptom score and then randomized to undergo standard (31) or isothermic (21) transurethral prostatectomy. During the standard procedure ambient temperature (21C) irrigant was used, while during isothermic prostatectomy warmed irrigant at 38C was used to prevent heat loss from the bladder, and a warming blanket and humidifying filter were used to decrease cutaneous and respiratory heat loss. Core temperature decreased by a mean of 0.8C (95% confidence interval -0.9 to -0.7) during standard transurethral prostatectomy and by 0.27C (-0.4 to -0.15) during the isothermic procedure. The standard prostatectomy group showed a significant hemodynamic response consisting of increased mean arterial pressure (p < 0.0002), increased index of systemic vascular resistance (p < 0.0001), bradycardia (p < 0.02), and decreased Doppler indexes of stroke volume (p < 0.005) and cardiac output (p < 0.001). The isothermic transurethral prostatectomy group was hemodynamically stable. These differences between the groups suggest that rapid central cooling exerted a significant effect on perioperative hemodynamic performance during transurethral prostatectomy.