Healthy Urethra Research Articles

SCHU-40: Continent Reconstructive Surgery of the Neurogenic Bladder

Renal function preservation and full urinary continence are the urological goals in our spinal cord injury population. To achieve this, a large capacity, low-pressure, permanent urinary retention emptied by intermittent self-catheterization is created. When necessary, anticholinergics are used to suppress hyperactive contractions or to increase capacity. If they fail, surgery is indicated. When the patient has a healthy urethra, acceptable manual dexterity and a continent sphincter, a detubularized bladder augmentation is performed.

Extended Urethral Mobilization in Incised Plate Urethroplasty for Severe Hypospadias: A Variation in Technique to Improve Chordee Correction

The feasibility of tubularized incised plate urethroplasty in proximal hypospadias with severe chordee was studied after correction of chordee by extended urethral mobilization. Boys with severe hypospadias who underwent tubularized incised plate urethroplasty were included. A total of 34 patients (28 with proximal penile/penoscrotal hypospadias and 6 with scrotal hypospadias) 18 months to 13 years old (mean 5 years) with severe hypospadias underwent tubularized incised plate urethroplasty between January 1999 and March 2006. A Gittes test was performed to assess the chordee after penile degloving and preservation of the urethral plate. Subsequently, the urethral plate with divergent corpus spongiosum and proximal healthy urethra were mobilized up to the bulbar urethra. Glanular chordee was corrected by mobilizing the urethral plate into the glans. The urethral plate was tubularized with or without incision and spongioplasty to complete the urethroplasty. Chordee correction was possible by mobilization of the urethral plate with corpus spongiosum from the meatus to the glans and the proximal urethra up to the bulbar region in 88% of the cases. Mean followup was 23 months (range 6 months to 3 years). Overall complication rate was 12% (fistula in 3 patients, meatal stenosis in 1). Two patients (6%) required dorsal plication, and in 2 (6%) the urethral plate had to be divided to correct the chordee. No patient had residual chordee during followup. The technique of chordee correction by mobilization of the urethral plate and proximal urethra with preservation of the urethral plate is simple and effective, and enlarges the scope of tubularized incised plate urethroplasty in severe hypospadias.

Use of ileum in reconstruction of the congenitally abnormal posterior urethra in two children

The construction of a posterior urethra when a healthy anterior urethra is not available is surgically challenging. We describe two children in whom the posterior urethra was constructed from a segment of ileum. Both children had a satisfactory outcome; one has been followed up for 10 years and one for 1 year.

Comparison of erbium:yttrium-aluminum-garnet and holmium:yttrium-aluminum-garnet lasers for incision of urethra and bladder neck in an in vivo Porcine model

To evaluate, in an animal model, differences in wound healing and scar formation in healthy urethra and bladder neck incised with the erbium (Er):yttrium-aluminum-garnet (YAG) and holmium (Ho):YAG lasers. In each of 18 domestic pigs, three 1-cm-long incisions were made, two at the bladder neck and one in the mid-urethra, using either the Er:YAG laser (9 pigs) or the Ho:YAG laser (9 pigs). In each laser group, 3 animals were killed on postoperative days 0, 6, and 14. The width of collateral damage, as evidenced by coagulation necrosis and granulation tissue at the wound base, and the incision depth were evaluated during tissue analysis. The collateral damage with the Er:YAG laser at postoperative day 0, 6, and 14 was 20 +/- 5, 900 +/- 100, and 430 +/- 100 microm, respectively. The collateral damage with the Ho:YAG laser was 660 +/- 110, 2280 +/- 700, and 1580 +/- 250 microm, respectively. The amount of granulation tissue was significantly less (P <0.05) at all time points with the Er:YAG laser. Similarly, the incision depths for the Er:YAG and Ho:YAG laser at postoperative day 6 (1100 +/- 200 microm versus 1500 +/- 300 microm, respectively) and 14 (670 +/- 140 microm versus 1240 +/- 140 microm, respectively) were also significantly less (P <0.05) for the Er:YAG laser group, indicating faster healing of the wound created. In this in vivo animal study, incisions in the urethra and bladder neck made with the Er:YAG laser healed faster and with less scar formation than incisions made with the Ho:YAG laser.

Valeur de l’échographie de surface par voie périnéale dans le diagnostic des sténoses de l’urètre antérieur

Objectives To determine the value of perineal sonography in the diagnosis of urethral stenosis and evaluation of surrounding fibrosis. Materials and methods Fifty-eight healthy subjects underwent urethral sonography. Thirty-two patients with suspected urethral stenosis underwent sonography after retrograde distension of the urethra using normal saline and retrograde urethrogram and voiding cystourethrogram. Results The mean diameters of the healthy urethra varied from 11 to 15mm. The mean thickness of normal periurethral tissue was between 2 and 4mm. Sonography detected 34 stenoses (97.4%). The length of the stenosis was significantly longer at sonography compared to retrograde urethrogram and voiding cystourethrogram. No significant difference was found between both techniques when measuring urethral diameter. In all cases, the thickness of periurethral tissues was greater at the stenotic level than at a normal level, irrespective of the involved segment. There was no correlation between the thickness of periurethral tissues and the degree of stenosis. Conclusion Urethral sonography is a method that permits diagnosis of urethral stenosis and evaluation of periurethral fibrosis. It may replace retrograde urethrogram and voiding cystourethrogram in the diagnosis of post infectious stenosis.

Stress Relaxation Phenomenon in the Healthy Female Urethra

Following dilatation, urethral pressure declines over the next few seconds to a state of equilibrium. The stress relaxation parameter, Pt0.5, was defined as the relative pressure decrease 0.5 s after dilatation, where the pressures at 0.1 s and at the new equilibrium were set to 100% and 0% respectively. Pt0.5 was calculated from 171 urethral dilatations performed at each of 3 urethral sites of measurement in 10 healthy volunteers. It was found to be independent of the rate and size of urethral dilatation. It showed a fairly high reproducibility rate when repeated after 1 h and 1 week. Pt0.5 was calculated to approximately 60% with no variation along the urethra. The parameter is assumed to be useful in evaluating urethral sphincter function. Although the method can be performed without special urodynamic equipment, the frequency response of the pressure measurement system must be adequate.

Surgical management of long urethral strictures

A total of 25 patients with a long urethral stricture involving the bulbomembranoprostatic urethra underwent excision of the afflicted region via the perineal approach with end-to-end anastomosis. Liberation of the distal urethra provided sufficient length for anastomosis without tension of the healthy urethra. Satisfactory results were obtained in 23 of the 25 patients without any functional disturbance of sphincter control. (J. Urol, 143: 917–919, 1990)

A MODIFICATION OF ULTZMANN'S SYRINGE FOR POSTERIOR URETHRAL INSTILLATIONS

The proper instillation of solutions into the posterior urethra has a well recognized value in the treatment of many of its chronic inflammatory conditions. The particular object in view is to insert the end of the instrument just beyond the external sphincter. The colliculus should not be touched or reached. It has been shown experimentally in animals that stimulation of a healthy urethra will not produce an antiperistaltic wave, whereas, almost invariably, stimulation of an inflamed colliculus produces antiperistalsis of the vas deferens, which, if we argue from analogy, in men would frequently carry infective material to the globus minor of the epididymis. The instruments introduced for giving these posterior urethral instillations have been quite numerous. The two types most frequently in use are the Ultzmann cannula, and the Guyon elastic catheter. The latter has the great advantage, because of the bulb at the end, that it can be more