Continence mechanism of the ileal neobladder in women: a urodynamics study.

We undertook this study to evaluate the mechanism of continence in women who underwent modified radical cystectomy and creation of an ileal neobladder. Our surgical technique was modified in accordance with detailed anatomic dissection of female pelvises with attention to the innervation of the pelvic musculature and urethral sphincter. Ten women aged 41-71 years (mean 64.3 years) underwent nerve-sparing radical cystectomy and creation of an orthotopic neobladder with detubularized ileum. Videourodynamic evaluation was performed 6 months postoperatively to evaluate sphincteric and reservoir function. Seven of the ten patients were totally continent after the procedure, requiring no protective pad. Of these, one requires intermittent self-catheterization. Videourodynamic evaluation revealed a low-pressure reservoir with a mean capacity of 467 ml, and leakage did not occur during Valsalva maneuver. Three patients reported significant incontinence (more than one pad per day) after orthotopic reconstruction. These patients demonstrated intrinsic sphincteric deficiency with a low mean abdominal leak-point pressure of 48.3 cmH2O. Two of these women had stress incontinence preoperatively. In conclusion, continence can be preserved in most women after modified radical cystectomy and orthotopic bladder replacement. Success results from preservation of the intrinsic sphincteric mechanism and the creation of a low-pressure, compliant reservoir. A history of stress incontinence preoperatively appears to predispose to sphincteric weakness postoperatively.

Systematic sextant biopsies in the prediction of extracapsular extension at radical prostatectomy.

OBJECTIVES: To evaluate the clinical utility of transrectal ultrasound-guided systematic sextant needle biopsies in the prediction of extracapsular extension (ECE) at radical prostatectomy. METHODS: A retrospective analysis of 104 men who underwent systematic biopsy and radical prostatectomy at our institution was performed. All patients underwent preoperative staging by transrectal ultrasound and transrectal ultrasound-guided systematic sextant biopsy. The presence of pathologic ECE was correlated to the number of positive core biopsies on each side of the prostate by chi-square analysis. Sensitivity, specificity, positive and negative predictive values, and likelihood ratios (LRs) were calculated for both positive (two or three biopsies positive per side) and negative (no or one positive biopsy per side) test results. RESULTS: Forty-two (20.2%) of 208 sides demonstrated evidence of ECE at radical prostatectomy. Chi-square analysis demonstrated a significant correlation between the number of positive biopsies and the presence of ECE at radical prostatectomy (P = 0.001). Overall, the finding of multiple positive core biopsies (two or three per side) had predictive value with regard to the presence of ECE (sensitivity 62%, specificity 77%, positive predictive value 40%, negative predictive value 89%). The corresponding LRs were 2.5 for a positive and 0.5 for a negative test result. CONCLUSIONS: The probability of ECE at radical prostatectomy can be more accurately assessed preoperatively by the combined use of transrectal ultrasound and systematic sextant needle biopsies.

Continence mechanism of the isolated female urethra: an anatomical study of the intrapelvic somatic nerves.

PURPOSE: A neuroanatomical study was initiated to gain better insight into the continence mechanism of the isolated urethra in women. MATERIALS AND METHODS: We performed a detailed gross and histological neuroanatomical study to identify the intrapelvic somatic pathway from the sacral spinal cord to the female urethral sphincter. Gross anatomical dissection was performed in 5 formalin fixed female adult pelvises by tracing the autonomic nerves from the pelvic plexus and the spinal somatic nerves from S2-S4 to the urethral sphincter. Immunohistochemical staining of urethral step sections with a neuropeptide specific antibody was performed to demonstrate the course of the periurethral somatic nerves in relation to the vaginal wall. RESULTS: Our study demonstrated an intrapelvic somatic pathway derived from the S2, S3 and S4 sacral roots, distinct from the peripheral pudendal nerve, supplying the levator ani and the urethra. The somatic nerves travel beneath the endopelvic fascia in close relation to the inferior vascular pedicle of the bladder and are susceptible to injury during radical pelvic surgery. Mixed autonomic fibers from the pelvic plexus travel along the course of the ureter and are also intimately associated with the vascular pedicle of the bladder. Immunohistochemical staining of urethral step sections demonstrated that the periurethral nerves travel in close relation to the lateral and anterior vaginal wall. CONCLUSIONS: We believe that the identification of intrapelvic somatic pathways to the urethra provides a basis for developing surgical techniques to preserve urethral somatic innervation during radical pelvic surgery in women.

Hemodynamic changes after complete unilateral ureteral obstruction in the young lamb.

PURPOSE: We studied renal hemodynamic changes after complete acute unilateral ureteral obstruction in the young lamb. MATERIALS AND METHODS: Seven 4-week-old lambs underwent unilateral complete ureteral obstruction and renal blood flow was monitored in both kidneys with ultrasonic flow transducers. Ureteral and arterial blood pressure was measured. RESULTS: In the obstructed kidney renal blood flow was stable for 5 hours and then decreased thereafter to 71% of baseline at 5 days (p < 0.05). In the contralateral kidney the pattern of renal blood flow constituted a mirror image, although the magnitude of the increase was decreased (122% of baseline at 5 days, not statistically significant). Mean arterial blood pressure did not change in 5 days. Mean ureteral pressure increased from a baseline of 9 to 37 mm. Hg (p < 0.001) 2 hours after obstruction but gradually decreased to 24 mm. Hg after 24 hours and remained elevated for 5 days (p < 0.001). CONCLUSIONS: The pattern of renal blood flow and ureteral pressure response to obstruction in the young lamb is different from that previously reported. Renal blood flow does not increase after obstruction and it is relatively preserved at 5 days. This unexpected response may be a result of the compound caliceal sheep kidney, immaturity of the young vascular system or development differences in the mechanism of spontaneous decompression of the collecting system.

Smooth and striated muscle development in the intrinsic urethral sphincter.

PURPOSE: The intrinsic urethral sphincter is composed of adjacent striated and smooth muscle. We studied the sequential expression of smooth and striated muscle proteins to gain insight into the ontogeny of intrinsic sphincter development. MATERIALS AND METHODS: The intrinsic urethral sphincters of timed Fischer 344 rat embryos at 14, 16 and 18 days of gestation, neonates on postnatal day 1 and adult animals were examined. Serial sections of the urethra and adjacent levator ani muscles were studied histologically with hematoxylin and eosin, anti-alpha-smooth muscle actin, anti-alpha-sarcomeric actin and antistriated muscle myosin heavy chain antibodies. RESULTS: The intrinsic urethral sphincter was identified within the periurethral mesenchyma as early as day 14 of gestation. Although striated myotubules were identified within the urethra by hematoxylin and eosin staining starting on postnatal day 1, striated muscle myosin heavy chain protein was absent in the embryonic and neonatal development of the sphincter, and it was expressed only in the mature myotubule of adults. alpha-Smooth muscle actin was expressed throughout the urethral sphincter of embryonic and neonatal animals. In adults alpha-smooth muscle actin was confined to the smooth muscle component of the urethra. Co-expression of alpha-smooth and alpha-sarcomeric muscle actin by the striated sphincter myotubule was noted only in neonates. CONCLUSIONS: Development of the intrinsic urethral sphincter is characterized by sequential expression of well characterized muscle marker proteins. The co-expression of smooth and striated muscle markers by developing sphincter myotubule suggests the possibility that trans-differentiation of smooth to striated muscle occurs in the developing genitourinary tract.

The effect of cryosurgical ablation of the prostate on erectile function.

OBJECTIVE: To investigate the incidence and identify the possible cause of erectile dysfunction after cryoablation of the prostate. PATIENTS AND METHODS: Erectile function was examined prospectively in 15 sexually active men (aged 59-72 years) who underwent cryoablation of the prostate for clinically localized prostate cancer. Erectile function was assessed before and 6 months after treatment; after intracavernosal injection with 10 micrograms of prostaglandin E1 (PGE1), the degree and duration of erection, the size of the cavernosal arteries, the penile arterial blood flow velocity, and the time to achieve peak flow were evaluated using high-resolution ultrasonography and colour pulsed-Doppler spectral analysis. RESULTS: Post-operatively, all patients initially reported an inability to achieve an erection sufficient for vaginal intercourse. At 6 months' follow-up, erectile dysfunction persisted in nine, with minimal or no response to the intracavernosal PGE1 injections, there was a significant decrease in the peak velocity of blood flow within cavernosal arteries and a significant increase in the time to achieve peak arterial flow. CONCLUSION: Although many factors may contribute to erectile dysfunction after cryoablation of the prostate, vascular injury plays a major role.

Ultrasound evaluation of the penis for assessment of impotence.

Image directed Doppler ultrasonography of the cavernous arteries provides functional, quantifiable assessment of penile arterial flow during a pharmacological erection. In this respect, this modality is superior to arteriography as a means of evaluating arteriogenic impotence. Peak flow velocity, arterial dilatation, and vessel pulsation are the most reliable ultrasonic indicators of arterial health. Aberrant arterial anatomy should be noted as this may contribute significantly to total penile blood flow. A thorough understanding of erectile physiology and anatomy is necessary to properly perform and interpret Doppler ultrasound results.

Phthalocyanine photodynamic therapy: new strategy for closure of choroidal neovascularization.

Chloro-aluminum sulfonated phthalocyanine (CASPc) is a photo-chemically active dye employed in photodynamic therapy (PDT). CASPc is a potent generator of singlet oxygen when irradiated with 675 nm light and is also capable of fluorescence, allowing visualization of the dye in tissues. We devised an angiography system using CASPc fluorescence to determine its localization in experimental choroidal neovascularization in monkeys and then investigated the ability of CASPc to produce photochemical closure of neovascularization upon irradiation with 675nm laser light. Fluorescent imaging indicated that CASPc localized angiographically in areas of neovascularization for at least 24 hours. Irradiation with 675 nm laser light 5-30 minutes after CASPc injection produced complete closure of choroidal neovascularization with minimal damage to overlying retina. We conclude that CASPc localizes in neovascular choroidal vessels and that CASPc photodynamic therapy can produce closure of these choroidal vessels.

Holmium-YAG laser surgery on experimental vitreous membranes.

We used a pulsed holmium-YAG laser that emitted in the midinfrared (2.12 microns) to cut experimental vitreous membranes in rabbits via an intraocular fiberoptic delivery system. Thirty-five membranes were treated at distances of 0.5 to 3.8 mm from the retina. All of the membranes that were treated were transected or partially cut. In cases that were treated with the optical fiber encased in a retinal-shielding pick, membranes could be readily transected without retinal injury. Laser vitreous membrane cutting may offer the advantage of near-tractionless membrane segmentation. The combination of a moderately strong target tissue absorption and the ready availability of commercial optical fibers for transmission of 2.12-microns laser energy suggests that the holmium-YAG laser merits further investigation for this application.