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At least 217 records · Page 12Linked to original sources
PubMed1999

Fetal partial urethral obstruction causes renal fibrosis and is associated with proteolytic imbalance.

PURPOSE: We determine whether fetal bladder outlet obstruction induces renal fibrosis, and is associated with an alteration in the regulation of connective tissue degradation and the presence of fibrogenic interstitial cells. MATERIALS AND METHODS: Partial bladder outlet obstruction was surgically induced in 33 fetal sheep at 95 days of gestation. These animals and 24 normal age matched controls were sacrificed at 109, 116 and 135 (term) days of gestation, and the kidneys were rapidly retrieved, drained and weighed. Representative whole kidney samples were snap frozen for assessment of deoxyribonucleic acid, protein and collagen content. Morphometric analysis and alpha-smooth muscle actin immunohistochemistry were performed on histological specimens from formalin fixed kidneys. Tissue extract from fresh kidney specimens were analyzed for metalloproteinase and tissue inhibitor of metalloproteinase activity. Urine samples obtained at the time of sacrifice were analyzed for electrolyte, creatinine and N-acetyl glucosaminidase excretion. RESULTS: All obstructed kidneys were hydronephrotic and larger than age matched controls. Obstructed kidneys at term showed interstitial fibrosis, as measured by increased extracellular matrix volume fraction (45% in male obstructed kidneys versus 2.5% in normal male kidneys, p = 0.0004), increased total collagen content (120 mg./kidney in male obstructed versus 20 mg. in normal male animals, p = 0.016) and collagen/deoxyribonucleic acid content per kidney (2.78 versus 0.53 mg./mg., p = 0.016). Metalloproteinase-1 activity was significantly lower in obstructed kidneys (210 versus 380 U./mg. protein in normal kidneys). Tissue inhibitor of metalloproteinase activity was undetectable in both groups. The presence of an increased population of myofibroblasts often associated with fibrotic processes was seen by alpha-smooth muscle actin staining which was localized to interstitial cells throughout the cortex in obstructed kidneys. CONCLUSIONS: Fetal partial bladder outlet obstruction induces renal interstitial fibrosis as early as 2 weeks after obstruction. A possible mechanism for this process is a shift in proteolytic activity to reduce matrix degradation in obstructed kidneys. These changes might be mediated by the increased number of fibrogenic interstitial cells. The observations suggest several potential approaches to developing an understanding of congenital obstructive uropathy.

Actins↗
PubMed1996

Pathophysiology of urethral obstruction.

Obstructive uropathy refers to abnormalities in structure or function of the urinary tract caused by impairment of normal flow of urine, and the resulting local and systemic effects of that impairment. Clinic consequences of obstructive uropathy are associated with abnormalities in fluid balance, electrolyte metabolism, acid-base balance, and retention of metabolic wastes. These consequences are partly due to build up of intravesical, ureteral, and renal pressure, influx of leukocytes into renal parenchyma resulting in release of cytokines, and alterations in intravascular hemodynamics. This article discusses pathophysiologic mechanisms and consequences of obstructive uropathy in cats.

Animals↗
PubMedDate not supplied

[Distal urethral obstruction in girls: a diagnosis to keep in mind].

Although obstruction of the distal urethra is uncommon in the female, it should not be discarded if the patient is a young girl who consults for symptoms as diverse as enuresis, frequency and urgency, urinary infections, etc. Such a case is reported herein. The patient underwent internal urethrotomy which resolved the obstruction and eliminated the symptoms.

Child↗
PubMed1996

The effect of radiotherapy on urethral obstruction from carcinoma of the prostate.

OBJECTIVE: To assess the impact of radiotherapy on the relief of complete bladder outlet obstruction requiring catheterization secondary to prostatic carcinoma. PATIENTS AND METHODS: From a consecutive series of 151 patients treated with radiotherapy for localized carcinoma of the prostate, 19 (12.6%; median age 72 years, range 59-83) who had an indwelling catheter in situ at the time of irradiation because of urinary retention, were analysed retrospectively and grouped according to the stage and grade of tumour and the irradiation dose delivered. RESULTS: The catheter was removed following radiotherapy in all but two patients, who both had stage 4 tumours, and normal urinary function was restored. The grade and stage of tumour did not influence the duration of catheterization. The median time from completion of radiotherapy to catheter removal was 10 weeks (range 0-46). Recatheterization was required in two patients at 3 and 64 months after radiotherapy and three patients, including these two, required transurethral prostatectomy (TURP) to relieve outlet obstruction. CONCLUSION: Prostatic radiotherapy is effective in relieving bladder neck obstruction caused by prostate cancer. Most patients will achieve normal urinary function without requiring TURP after treatment.

Aged↗
PubMed2006

[Balloon dilatation for lower urethral obstruction in children].

OBJECTIVE: To evaluate the clinical effect of balloon dilatation in the treatment of lower urinary tract obstruction in children. METHODS: Twenty-six boys suffering from lower urinary tract obstruction underwent the balloon dilatation operation. These patients included 23 cases of posterior urethral valves, 2 cases of anterior urethral valves and 1 case of traumatic urinary tract stricture. Their ages ranged from 18 days to 7 years. All the patients were diagnosed by voiding cystourethrogram (VCG). Some of the boys suffered from bilateral hydronephrosis and dilated ureters. Before operation, the patients with urine retention or abnormal renal function should drain urine and correct the disorder of fluid and electrolyte. Balloon dilatation was done after their conditions were improved. During operation, ketamine anaesthesia was used, and 30% diatrizoate meglumine was used as dilatation drug. The balloon catheters which had the length of 4 cm and the diameters of 5, 8,10 mm respectively were used for dilating the urethra. After operation, a Foley's catheter was routinely indwelled. RESULTS: During procedure, compression phenomena disappeared in the course of operation. All the patients urinated normally after catheter was removed at 1 week post operatively. 6 cases received ureteral reimplantation to prevent vesicoureteral reflux after 1 to 3 months. 25 patients were followed up from 1 to 13 years and all patients had normal micturition and the bilateral hydronephrosis were improved. CONCLUSION: Balloon dilatation is a safe, effective and feasible therapy for lower urinary tract obstruction in children.

Catheterization↗
PubMed1999

Nonbacterial prostatitis caused by partial urethral obstruction in the rat.

The pathogenesis of nonbacterial prostatitis (NBP) is not understood mainly due to the lack of appropriate experimental models. We developed a new experimental model of NBP by inducing a partial obstruction of the urethra (PUO) in the rat. Male Wistar rats aged 12 weeks were used. PUO was produced by a nylon ligature on the urethra over a rubber tube. The tube was slipped out after the ligature had been tied. Two rats were examined histologically 6 h, 1 day, 3 days and 7 days after PUO. In another group, two rats were killed at 1, 3 and 7 days after the release of the PUO that had been left in place for 3 days. On day 3, another eight rats with PUO and eight control rats had 2 ml of urine in the bladder replaced by the same volume of lucifer yellow (LY; 10 microg/ml, MW 500), microperoxidase (MP; 20 microg/ml, MW 1900), horseradish peroxidase (HRP; 10 microg/ml, MW 40 000), or saline as control, respectively. Lymphocytic infiltration and interstitial edema were noted in the prostate following PUO, being most prominent on day 3. After the release of the PUO, these inflammatory changes gradually disappeared. Only LY was noted within the prostatic stroma of the rats 2 h after bladder instillation. Intraprostatic urinary reflux may be an etiologic factor in NBP. The present study showed that lower urinary tract obstruction caused NBP in the rat. Penetration of prostatic tissue by low-molecular-weight substances in the urine may trigger NBP.

Administration, Intravesical↗
PubMed1990

Rupture of ileal neobladder due to urethral obstruction by mucous plug.

We report a case of ileal neobladder rupture after radical cystectomy due to mucus obstruction of the bladder neck. Since mucus production in bowel neobladders cannot be sufficiently influenced pharmacologically, patients with a continent urinary diversion connected to the urethra should learn self-catheterization.

Humans↗
PubMed2001

Transient urethral obstruction predisposes to ascending pyelonephritis and tubulo-interstitial disease: studies in rats.

Chronic tubulo-interstitial disease, an important cause of end-stage renal disease, often results from the combined effects of a disturbed urinary outflow tract and urinary tract infection. Acute unilateral ureteral obstruction in rats rapidly induces foci of medullary necrosis, confined to the region of the papilla and fornices. This injury may provide a nidus for bacterial invasion and may invoke reactive and regenerative changes, ultimately leading to chronic pyelonephritis and tubulo-interstitial nephropathy. To explore this possibility, adult rats underwent renal morphological evaluation 2-7 days following transient 24-h unilateral ureteral obstruction. In some experiments the bladder was inoculated with bacteria (10(8)-10(9) cfu/ml Escherichia coli in 0.5 ml) after release of ureteral obstruction, with subsequent cultures obtained from the pelvis of both kidneys and from the urinary bladder. Morphologic evaluation of perfusion-fixed kidneys, 2-7 days after the release of 24-h ureteral obstruction disclosed papillary necrosis, urothelial proliferation, marked inner-stripe interstitial expansion, and fibrosis and proximal tubular (S3) dilatation. The lateral (perihilar region) was predominantly affected, with lesions spreading from the fornices. There was some progression of interstitial fibrosis during the postobstructive time course or following more prolonged ureteral obstruction. By contrast, infection hardly contributed to the tubulointerstitial changes. In rats subjected to infection, cultures were positive in all 15 postobstructive kidneys, as opposed to five contralateral kidneys (P < 0.0001). Viable counts from the postobstructive kidney were also higher than those from the contralateral side (79,000 +/- 12,000 vs 2900 +/- 1600 cfu/ml, mean +/- SEM, P < 0.0001), and were comparable to those obtained from the bladder (77,000 +/- 13,000 cfu/ml). We conclude that transient ureteral obstruction predisposes to ascending pyelonephritis and to tubulointerstitial disease. This vulnerability may relate to altered urodynamics and medullary tissue destruction.

Animals↗
PubMed1992

The effect of experimental urethral obstruction and its reversal on changes in passive electrical properties of detrusor muscle.

The passive electrical properties of guinea pig detrusor muscle were studied in order to determine how bladder outflow obstruction and reversal might modify the electrical activity of the bladder and, thus, contractility. Experimental bladder outflow obstruction was produced in guinea pigs and resulted in an increase in bladder weight with a decrease in spontaneous electrical activity, membrane time constant and space constant. In addition, the membrane Na-K pump activity increased with obstruction. Following reversal of obstruction, bladder weight gain associated with obstruction was only partially reversible. The decrease in the membrane time constant induced by obstruction was almost fully reversible following release of obstruction. In contrast, the membrane space constant which reflects spread of current, in addition to spontaneous electrical activity, were only partially reversible. The membrane Na-K pump activity of the detrusor muscle decreased to control levels following reversal of bladder outflow obstruction. There was no significant change in the resting membrane potential of detrusor smooth muscle with either obstruction or following reversal of obstruction. These results suggest, that, the changes in the bladder smooth muscle membrane electrical properties induced by experimental bladder outflow obstruction are only partially reversible following release of obstruction. Furthermore, the results suggest that, the dysfunctional cystometric patterns associated with bladder outflow obstruction might not only be due to changes in detrusor innervation but, fundamental reorganization of the detrusor's electrical syncytium with irreversible suppression of cell-to-cell transfer of electrical activity.

Action Potentials↗
PubMed1980

Antenatal ultrasonic diagnosis of complete urethral obstruction in the fetus.

A case of ante-natal diagnosis of complete obstruction of the urethra is reported. By repeated ultrasonic B-scans a distended bladder filling the abdominal cavity could be seen, and a hydroureter was demonstrated. By early diagnosis of this condition, which is incompatible with life, a decision to terminate pregnancy can be made.

Adult↗
PubMed1978

Alpha-adrenergic agents in urinary disorders of the proximal urethra. Part II. Urethral obstruction due to "sympathetic dyssynergia".

Lower urinary tract obstruction in patients with neurological lesions can be due to "sympathetic dyssynergia". The obstruction can be at the level of the external sphincter. Phentolamine (i.v.) used during the voiding cystourethrogram helps to make the diagnosis. Phenoxybenzamine therapy produced improvement in 10 of 18 patients. As a rule, patients had to continue on the drug to maintain their response.

Adrenergic alpha-Antagonists↗
PubMed1995

Urethral pressure response to smooth and skeletal muscle relaxants in anesthetized, adult male cats with naturally acquired urethral obstruction.

The effects of the skeletal muscle-relaxing drug dantrolene sodium alone, and in combination with the alpha 1-adrenergic antagonist prazosin, on the urethral pressure profile were investigated in male cats with obstructive lower urinary tract disease. Decreases in mean segmental intraurethral pressure induced by dantrolene (n = 3) or dantrolene in combination with prazosin (n = 3) were evaluated statistically, using a paired design. Statistical analysis was applied to absolute (mm of Hg) pressure values. Intravenous administration of dantrolene alone (1 mg/kg of body weight, n = 3) significantly decreased pressure in the postprostatic/penile urethral segment, but did not decrease prostatic urethral pressures. Dantrolene in combination with prazosin (0.03 mg/kg IV) caused a 20% pressure decrease in the prostatic segment (P = 0.060). Preprostatic urethral pressure was not significantly affected by either treatment regimen in the small pool of cats studied. There was no difference in baseline pressures (mm of Hg) in the 3 intraurethral segments of these 6 recently obstructed male cats, compared with historic baseline pressures (mm of Hg) in the 3 intraurethral segments of 28 healthy male cats. These results indicate that dantrolene and prazosin may be effective in relaxing intraurethral skeletal and smooth musculature in male cats clinically afflicted with obstructive lower urinary tract disease. However, it is not certain that administration of muscle relaxants would facilitate urethral catheterization and removal of the obstruction in male cats with blockage of the lower urinary tract. Strikingly, results of this study suggest that urethral muscle spasm had a minor role in these cats.

Animals↗
PubMed1985

Urethral obstruction secondary to carcinoma of prostate: response to endocrine treatment.

Of 749 patients with carcinoma of the prostate 133 (17.8%) presented with total urinary retention; 122 of the 133 patients were given different forms of endocrine therapy. Only 8 patients were treated by initial transurethral resection of the prostate, and 3 patients received no treatment. After endocrine therapy 80 (65.6%) of 122 patients were free from catheter six months after starting treatment. The response to orchidectomy appeared earlier than that to treatment with estrogens. The mean period of catheterization for the 80 patients who responded was 2.7 months after orchidectomy and 3.4 months during estrogen treatment. The difference was statistically significant (p less than 0.05).

Adenocarcinoma↗
PubMed1994

Stent of shape-memory alloy for urethral obstruction caused by benign prostatic hyperplasia.

Dilation and positioning a stent in the prostatic urethra have become important alternatives for the management of benign prostatic hyperplasia (BPH), but both have significant drawbacks, namely the need to repeat the treatment in the former case and the conflict between the introducing means and the generation of sufficient expansile force in the latter case. A spiral of a Chinese titanium-nickel alloy with shape memory was implanted in 25 patients with BPH using a self-made coaxial sheath. With a follow-up of 3 to 20 months, the success rate is 92%. There has been no encrustation or migration of the spirals. We deem the spiral of this shape-memory alloy to be a good alternative in patients with BPH who are unfit for surgery.

Aged↗
PubMed1987

Alternative treatment of prostatic urethral obstruction secondary to benign prostatic hypertrophy. Non-surgical balloon catheter prostatic dilatation.

Benign prostatic hypertrophy (BPH) produces symptoms that currently can only be treated surgically either by open or endoscopic prostatectomy. We have undertaken animal (1) and human studies to determine if invasive radiologic techniques utilizing balloon catheters could be applied to the treatment of this common ailment. We report a series of twelve patients treated by retrograde transurethral balloon catheter prostatic dilatation. The procedure is performed using topical anesthesia with a specially designed balloon catheter (Medi-Tech, Inc.). The procedure is done on an outpatient basis and is completed within approximately 15 minutes. Relatively long-term results have resulted in persistent relief of symptoms. No complications have been encountered. We anticipate that balloon dilatation of the prostatic urethra will have a major impact on the treatment of BPH based on the promising preliminary results. Transurethral resection of the prostate (TURP) is associated with moderate morbidity and significant cost which can be reduced by the proposed procedure.

Catheterization↗
PubMed1996

Urethral obstruction after anti-incontinence surgery in women: evaluation, methodology, and surgical results.

OBJECTIVES: To evaluate a group of women with voiding dysfunction and a low maximum flow rate (MFR) (less than or equal to 12 mL/s) after surgery for stress urinary incontinence (SUI); to establish diagnostic parameters indicating obstruction in an attempt to determine treatment selection; and to evaluate preliminary surgical results. METHODS: Eighteen women who underwent anti-incontinence surgery for SUI were diagnosed as having infravesical obstruction (IO). Thirteen women (group A [72%]) presented with clinically predominant symptoms of urgency, frequency, intermittency, and a variable vesical residual volume (RV), and five (group B [28%]) had as their most significant symptoms a high vesical RV and urinary tract infection that had been managed with intermittent catheterization (IC). The diagnosis of IO, suspected after clinical history, was established after physical examination and cystoscopic, cystographic and urodynamic investigations. RESULTS: Bladder instability was demonstrated in 6 group A patients (46%) and 1 group B patient (20%) (P = NS). Mean MFRs were 8.07 and 7.2 mL/s, respectively, in both groups (P = NS). Mean maximal voiding pressures (MVPs) were 20.23 and 5 cm H20, and mean RVs were 57.46 and 174 mL, respectively; both differences were statistically very significant (P <0.01 and P <0.001, respectively). High to normal MVPs occurred in 2 patients overall (11%). Bladder neck overcorrection, midurethral distortion, and postsurgical cystocele were demonstrated in both groups in 11 (85%), 0, and 2 (15%) patients in group A and 3 (60%), 2 (40%), and 3 (60%) patients in group B, respectively (P = NS). Patients in group A were treated surgically with cystourethrolysis and a repeated, less obstructive anti-incontinence operation. In group B 2 women (40%) had a similar surgical procedure; 1 (20%) underwent isolated urethrolysis; and 2 (40%) are currently maintained with IC. CONCLUSIONS: Among these 18 patients with voiding dysfunction after anti-incontinence surgery, a primary diagnosis of IO was established clinically. Only patients with a low MFR were selected for this study. Cytographic and endoscopic investigation as well as the presence of postsurgical cystocele assisted in establishing the diagnosis. The success rate with urethrolysis and resuspension was 60% for the 13 women with predominantly urgency, frequency, and the highest MVPs (20.23 +/- 9.67 cm H20 [group A) and 33% for the 5 women with urinary retention presenting the lowest MVPs (5.00 +/- 7.07 cm H20 [group A]) and 33% for the 5 women with urinary retention presenting the lowest MVPs (5.00 +/- 7.07 cm H20 [group B]). An added resuspension procedure is probably unnecessary in the latter group of patients and requires careful individual selection in the former group.

Adult↗