The vascular component in the production of intraurethral pressure

Evaluation of the vaginal and urinary microbiota of healthy cycling bitches

BACKGROUND

While the urogenital microbiota has recently been characterized in healthy male and female dogs, the influence of sex hormones on the urogenital microbiome of bitches is still unknown. A deeper understanding of the cyclic changes in urinary and vaginal microbiota would allow us to compare the bacterial populations in healthy dogs and assess the impact of the microbiome on various urogenital diseases. Therefore, the aim of this study was to characterize and compare the urogenital microbiota during different phases of the estrous cycle in healthy female dogs. DNA extraction, 16 S rDNA library preparation, sequencing and informatic analysis were performed to determine the vaginal and urinary microbiota in 10 healthy beagle dogs at each phase of the estrous cycle.

RESULTS

There were no significant differences in alpha and beta diversity of the urinary microbiota across the different cycle phases. Similarly, alpha diversity, richness and evenness of vaginal bacterial populations were not significantly different across the cycle phases. However, there were significant differences in vaginal beta diversity between the different cycle phases, except for between anestrus and diestrus.

CONCLUSION

This study strongly suggests that estrogen influences the abundance of the vaginal microbiota in healthy female dogs, but does not appear to affect the urinary microbiome. Furthermore, our data facilitate a deeper understanding of the native urinary and vaginal microbiota in healthy female dogs.

Adjustable vs. ordinary transobturator tape for female stress incontinence. Is there a difference?

Objectives

To determine whether there are any significant differences in complications and success rate between adjustable transobturator tape (TOA) and ordinary transobturator tape (TOT) in the treatment of female stress urinary incontinence (fSUI), as the TOA was recently introduced for the treatment of female SUI, its advantage being the ability to adjust the tape after surgery to address over- or under-correction.

Patients and methods

In all, 96 women with SUI (mean age 53 years, SD 10) were included in the study. Patients were randomised into two equal groups (group 1, TOA, vs. group 2, TOT). The operative duration, blood loss, intra- and post-operative complications, and the success rate, were compared between the groups.

Results

There was no statistically significant difference between the groups in cure rates (83% vs. 80%, groups 1 and 2, respectively) or in postoperative stay. The mean operative duration in group 2 was significantly shorter than in group 1. No intraoperative bleeding requiring a blood transfusion was recorded, and there were no bladder injuries. Postoperative adjustment of the tape was only required in three patients in group 1.

Conclusions

The TOA is a safe and accurate method for treating fSUI, but with experienced surgeons there was no difference in the cure rate and postoperative outcome between TOA and TOT.

Urodynamic and morphometric characteristics of the lower urogenital tracts of female Beagle littermates during the sexually immature period and first and second estrous cycles

OBJECTIVE

To compare values of lower urogenital tract urodynamic and morphometric variables determined during the prepubertal (sexually immature) period and first and second estrous cycles in healthy female Beagle littermates to determine functional and anatomic changes of the lower urogenital tract during those periods.

ANIMALS

5 female Beagle littermates.

PROCEDURES

Urethral pressure profilometry, diuresis cystometry, and vaginourethrography were performed when dogs were 3.5, 4.5, 5, 6, 7, 8, 8.5, and 9 months old and during proestrus; estrus; early, middle, and late diestrus; and early and late anestrus of the first and second estrous cycles.

RESULTS

At the end of the prepubertal period, values of urodynamic and morphometric variables increased significantly, compared with values at earlier times. Maximum bladder capacity developed when dogs were 9 months old. In all dogs, the bladder was intermittently located in an intrapelvic position during the prepubertal period; the bladder was intra-abdominal from the time dogs were 9 months old until the end of the study. Urethral pressure decreased significantly during estrus and early diestrus of the first and second estrous cycles. Bladder capacity increased significantly during diestrus of both estrous cycles. Urethral and vaginal lengths were significantly longer during proestrus and estrus than they were during anestrus.

CONCLUSIONS AND CLINICAL RELEVANCE

Values of lower urogenital tract urodynamic and morphometric variables were influenced by age and phases of the estrous cycle of immature and young adult Beagles in this study. Age of dog and phase of estrous cycle should be considered when interpreting urodynamic and vaginourethrography data.

The role of angiotensin II in stress urinary incontinence: A rat model

AIMS

Pharmacological treatment for stress urinary incontinence (SUI) is limited to the use of non-selective alpha-agonists, which are often ineffective. Non-adrenergic mechanisms have also been implicated in urethral closure, including angiotensin II (Ang-II), which has been demonstrated throughout the urinary tract. We investigate the role of Ang-II in urethral tone in a rat model of SUI.

METHODS

Abdominal leak point pressure (ALPP) and retrograde urethral pressure profilometry (RLPP) were measured in 70 female virgin rats. Thirty rats underwent pudendal nerve injury (PNT), 30 had circumferential urethrolysis (U-Lys), and 10 had sham surgery. Rats received daily doses of Angiotensin Type 1 (AT-1) receptor inhibitor (20 mg/kg), Angiotensin Type 2 (AT-2) receptor antagonist (10 mg/kg), or Ang-II (2 mg/kg).

RESULTS

Following U-Lys, RLPP and ALPP decreased from 21.4 +/- 2.0 and 39.2 +/- 3.3 mm Hg, to 13.1 +/- 1.5 and 21.6 +/- 1.9 mmHg, respectively (P < 0.01). After PNT, RLPP, and ALPP decreased from 21.0 +/- 1.6 and 41.9 +/- 3.0 mmHg to 13.1 +/- 1.5 and 24.7 +/- 3.3 mmHg, respectively (P < 0.01). AT-1 inhibitor caused significant decrease in RLPP and ALPP from 21.0 +/- 6.2 and 41.8 +/- 9.4 mmHg, to 12.0 +/- 3.8 and 25.6 +/- 6.6 mmHg, respectively (P < 0.01). Likewise, AT-2 treatment reduced RLPP and ALPP from 21.4 +/- 6.3 and 40.1 +/- 1.7 mmHg, to 13.5 +/- 5.7 and 31.0 +/- 7.2 mmHg, respectively (P < 0.01). Following surgery, Ang-II administration restored RLPP and ALPP to baseline presurgical values.

CONCLUSIONS

AT-1 and AT-2 receptor inhibition significantly lowers urethral resistance, comparable to either neurogenic or urethrolytic injury. Ang-II treatment restored urethral tone in rats with intrinsic sphincter dysfunction. Ang II appears to serve a functional role in the maintenance of urethral tone and stress continence.

Effects of tamsulosin on resting urethral pressure and arterial blood pressure in anaesthetized female dogs

The purposes of the present study were to investigate the effects of the alpha1-adrenoceptor antagonists tamsulosin, prazosin and urapidil on resting urethral pressure in anaesthetized female dogs, and to compare the results with their effects on arterial blood pressure. Tamsulosin decreased resting maximal urethral pressure in the urethral pressure profile in a dose-dependent fashion, whereas it had almost no effect on mean arterial blood pressure. Prazosin and urapidil also dose-dependently decreased resting maximal urethral pressure, but these effects were accompanied by decreases in mean arterial blood pressure. Thus, of these three compounds, tamsulosin dose-dependently decreased resting maximal urethral pressure with negligible effect on mean arterial blood pressure in female dogs. These results suggest that tamsulosin will be useful in the treatment of voiding dysfunction associated with bladder outlet obstruction in women, with little hypotensive effect.

Functional correlates of Doppler flow study of the female urethral vasculature

OBJECTIVES

To examine the effect of individual patient factors (age, parity, body mass index, menstrual cycle, menopause, hormone replacement therapy, bladder neck position and urethral mobility) on the appearance of Doppler flow in urethral vessels, to investigate the association between the Doppler flow parameters and intrinsic urethral function, storage and voiding, and to explore differences in the urethral vasculature between subjects with and without urodynamic stress incontinence (USI).

METHODS

Over a 4-year period we prospectively performed imaging studies in 355 women, including 244 who denied any lower urinary tract symptoms within the previous 3 months (Group A) and 111 who had had lower urinary tract symptoms (Group B). Studies included morphologic assessment and Doppler flow investigation of the lower urinary tract. Vascular flow velocity and vessel density in the urethral vasculature were measured. For women in Group B, multichannel urodynamic studies were also performed.

RESULTS

The urethral vasculature has five main branches of vessels. Their appearance was not affected by the menstrual cycle or menopause except for those of the anterior vaginal vessel and anterior branch of the middle urethral vessel. Other than that of the posterior urethral vessel, in which there was a correlation with parity, the resistance index (RI) was not affected by individual patient factors. However, there was a correlation between the vascular index (VI) and individual factors such as age (r = -0.336, P = 0.002), body mass index (r = -0.287, P = 0.028), menopause (r = -0.402, P < 0.001), and hormone replacement therapy (r = 0.392, P = 0.027). Only the VI and RI of the posterior urethral vessel correlated significantly with the urethral pressure profile. In subjects with lower urinary tract symptoms, the appearance of the urethral vasculature on power Doppler imaging and the corresponding RI and VI values were not correlated with objective evidence of USI.

CONCLUSION

Patient factors may affect specific Doppler flow parameters of the urethral vasculature, which are related to intrinsic resting urethral closure. There is no difference in the appearance of the urethral vasculature in subjects with or without USI.

Evaluation of the urodynamic and hemodynamic effects of orally administered phenylpropanolamine and ephedrine in female dogs

OBJECTIVE

To compare the urodynamic and hemodynamic effects of different dosages of phenylpropanolamine and ephedrine and determine effective dosages in increasing urethral resistance in female dogs.

ANIMALS

20 sexually intact female Beagles.

PROCEDURE

Dogs were allocated into 4 groups and received phenylpropanolamine once, twice, or 3 times daily, or ephedrine twice daily, for 14 days. On days 0, 7, and 14, urethral pressure profiles were performed while dogs were anesthetized with propofol. Variables recorded included maximum urethral pressure, maximum urethral closure pressure, integrated pressure, functional profile length, anatomic profile length, plateau distance, distance before maximum urethral pressure, and maximum meatus pressure. Arterial and central venous pressures were measured before anesthetic induction and 10 and 35 minutes after induction.

RESULTS

Administration of phenylpropanolamine once daily or ephedrine twice daily significantly increased maximum urethral pressure and maximum urethral closure pressure. Values for integrated pressure were significantly increased after 14 days of once-daily administration of phenylpropanolamine. Variables did not change significantly from day 7 to day 14. Diastolic and mean arterial blood pressures increased significantly during the treatment periods, and arterial pressure decreased during propofol infusion.

CONCLUSIONS AND CLINICAL RELEVANCE

Oral administration of phenylpropanolamine once daily or ephedrine twice daily increased urethral resistance in clinically normal dogs and may be recommended for management of urethral sphincter mechanism incompetence. Treatment efficacy may be assessed after 1 week. Dogs with concurrent cardiovascular disease should be monitored for blood pressure while receiving alpha-adrenergic agents because of the effects on diastolic and mean arterial pressure.

Expression of vascular endothelial growth factor in the lower urinary tract in rats after castration and estrogen administration

OBJECTIVE

To evaluate quantitatively, by means of immune histochemistry, the expression of the vascular endothelial growth factor (VEGF) in the bladder, vesicourethral junction, and urethra in normal, castrated adult rats and under estrogen administration.

DESIGN

Sixty adult virgin rats (Rattus norvergicus albinus, Rodentia, Mammalia) from the CEDEME-UNIFESP Animal House were used. Rats were divided into three groups. Group I comprised noncastrated rats, group II comprised oophorectomized rats, and group III comprised castrated rats administered 17beta-estradiol in the form of subcutaneous implants at the dose of 0.18 mg/implant for 30 days. After performing standard immunohistochemistry procedures, the intensity of the dark-brown color was used as the cytoplasmic protein expression of VEGF. Cells without this coloration or weakly stained were considered negative. percentile of VEGF expression was obtained by counting 1,000 cells per slide and establishing the ratio between positive and total cells.

RESULTS

The VEGF expression was uniform and similar along the urinary tract in group I. After castration, protein expression was almost absent in the bladder and was low in the vesicourethral junction and urethra. With estrogen replacement, very little of the expression was recovered in the bladder, and the reaction became evident in the vesicourethral junction and urethral sections.

CONCLUSIONS

The present study implies a potential relationship between VEGF and urinary tract physiology. The results suggest that there are quantitative differences in VEGF expression in these tissues depending on steroid hormone status.

Bladder neck pubovaginal slings

Over the past 30 years, the pubovaginal sling has surpassed retropubic and transvaginal suspensions as the most common surgical operation for correcting stress urinary incontinence. This resurgence has been due in part to innovative technological advances that have shortened operative times and expedited postoperative recovery. The introduction of novel allografts, xenografts and synthetic materials has also been accompanied by unique complications, previously not encountered with autologous materials. The aim of this review is to compare the available sling materials in the context of biocompatibility and efficacy.

Influence of the estrous cycle on urodynamic and morphometric measurements of the lower portion of the urogenital tract in dogs

OBJECTIVES

To compare the values of the urodynamic parameters of the lower portion of the urinary tract and vaginourethral measurements obtained during the phases of the estrous cycle in dogs and determine possible functional or anatomic modifications of the lower portion of the urinary tract associated with those phases.

ANIMALS

7 adult female Beagles.

PROCEDURE

Urethral pressure profilometry, diuresis cystometry, and vaginourethrography were performed in each dog during proestrus; estrus; early, mid, and late diestrus; and early and late anestrus. The maximum urethral pressure (MUP), maximum urethral closure pressure (MUCP), urethral functional and anatomic profile lengths (UFPL and UAPL, respectively), integrated pressure, threshold pressure, threshold volume, compliance, urethral length, and vaginal length and width were measured.

RESULTS

For all measurements, significant interindividual variation was detected. Integrated and threshold pressures, APL, and each morphometric value significantly increased from late anestrus to proestrus. Compared with other phases, MUP, MUCP, and integrated pressure values were significantly lower in estrus and early diestrus; UAPL and UFPL values were significantly lower in late diestrus. At each cycle phase in old dogs, MUP, MUCP, threshold pressure, and vaginal length and width were significantly lower (except in proestrus for vaginal measurements) and threshold volume and compliance values were significantly higher, compared with middle-aged dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Urodynamic and morphometric measurements of the lower portion of the urogenital tract are affected by the changes in hormonal balance that occur during the estrous cycle. In sexually intact female dogs, estrous phase determination is important for the interpretation of urodynamic data.

Effects of tamoxifen on Doppler velocimetry parameters of periurethral vessels in postmenopausal women

The purpose of the present study was to assess the effect of tamoxifen on periurethral vessels by Doppler velocimetry examination. Increase in the number of these vessels as well as decrease in resistance and pulsatility indices by tamoxifen were observed.

Genuine stress incontinence theories of etiology and surgical correction

Urinary loss (flow) results from a relative lack of CM resistance with respect to the intravesical pressure. Surgical stabilization of the continence mechanism, at the level of the bladder neck or mid-urethra, compensates for the existing loss of urethral support and function by creating new zones for compression, absorption of transmitted pressure, and the preservation of sphincteric configuration. Our understanding of the pathophysiology of stress incontinence and the basis for surgical compensation continues to evolve. Mid-urethral complex support procedures have stimulated further investigation into the mechanics of continence.

The menopause: health implications and clinical management

OBJECTIVE

To review the anatomy, physiology, clinical symptoms, long-term health effects, and treatment of the menopause and climacteric syndrome, with a special emphasis on features, such as incontinence, particularly relevant to geriatric medicine.

DATA SOURCES

English-language publications on menopause and the climacteric.

STUDY SELECTION

Articles and books containing recent information pertinent to the topics covered. Studies in human subjects were given priority, but primate studies that amplify physiologic concepts are included.

DATA SYNTHESIS

Due to increased longevity, the average US woman will spend one-third of her life as a postmenopausal individual. Anatomic and physiologic changes associated with the peri- and postmenopausal state include hot flushes, genitourinary atrophy, and bone loss. Possible correlates of the menopausal transition and postmenopause include affective changes and unfavorable alterations in lipoproteins and other cardiac risk factors. Clinical correlates of these changes can include incontinence, sexual dysfunction, increased risk of fracture, dysphoric mood, and increased risk of cardiovascular disease. Formal indications for estrogen therapy are hot flushes, genital atrophy, and osteoporosis prevention; other common clinical uses are reviewed. Non-contraceptive estrogens can be administered orally, transdermally, vaginally, or by injection. Each route and preparation has some unique features with respect to actions and side effects. Progestins, in adequate doses, protect against the unwanted side effect of endometrial hyperplasia; alternatives to progestin use are presented. Non-hormonal alternatives for some peri- and postmenopausal symptoms are described.

CONCLUSIONS

A discussion of the menopause and the benefits and risks of hormone therapy should be part of the routine health care of older women. Since the use of hormone therapy is elective, health care providers must elicit the goals, needs, and preferences of each patient, supply her with relevant information, and serve as a facilitator of her individual decision.

Effects of estrogen on urethral function in women with urinary incontinence

In a prospective study, 2 gm of conjugated estrogen vaginal cream was administered daily for a total of 6 weeks in a group of 11 postmenopausal women with urodynamically proved genuine stress incontinence. Midurethral cytologic studies and a complete clinical and urodynamic evaluation were performed twice at 6-week intervals. Clinically, six of the 11 patients (54.5%) were cured or improved significantly after estrogen treatment, whereas the other five patients (45.5%) were clinically unchanged. The favorable clinical response correlated with urodynamic findings of increased urethral closure pressure and improved abdominal pressure transmission to the proximal urethra (p less than 0.05); in the patients who had a poor clinical response to estrogens, no significant changes in urethral dynamics were noted. Changes in urethral cytologic findings also correlated well with clinical and urodynamic findings. Patients with a favorable response to estrogen showed a maturation change from transitional to intermediate squamous epithelium (p less than 0.02), whereas nonresponders showed no significant changes in urethral cells.

Effects of five alpha-blockers on the hypogastric nerve stimulation of the canine lower urinary tract

Electrical stimulation of the hypogastric nerve increased both urethral and bladder pressures of anaesthetized male dogs, without affecting cardiovascular parameters. Intravenous injections of prazosin, phentolamine, thymoxamine, phenoxybenzamine and yohimbine inhibited the urethral pressure increase in a dose-dependent manner, but the increase in bladder pressure was not modified by these alpha-blockers.

Non-neuromuscular determinants of intraluminal urethral pressure in the female baboon: relative importance of vascular and nonvascular factors

The female urethral sphincteric mechanism has both neuromuscular and non-neuromuscular components. The latter component has several determinants, including the urethral mucosa, the connective tissue of the urethra and periurethra, and the submucosal vascular bed. This study was designed to characterize the non-neuromuscular component of the urethral pressure profile (UPP) by quantitating the relative contributions of its vascular and non-vascular determinants in four female baboons. Following minimization of the smooth muscle and striated muscle determinants (the neuromuscular component) with halothane and pancuronium bromide, UPPs were performed before and after aortic occlusion. It is concluded that vascular and non-vascular factors contribute nearly equally to the non-neuromuscularly generated portion of intraluminal urethral pressure.

Effect of oestrogen and progesterone on the blood flow in the lower urinary tract of the rabbit

The effects of oestrogen and of oestrogen combined with progesterone were examined on the fractional distribution of cardiac output (blood flow) in the genitourinary tissues of the female rabbit. Oestradiol treatment significantly increased blood perfusion in the uterus, vagina and urethra but caused no change in the perfusion of the urinary bladder or the kidneys. The wet weight of the uterus and vagina increased significantly and in the urethra there was a tendency to weight gain following oestradiol treatment. Progesterone treatment following oestrogen appeared to reduce the effect of oestrogen on both perfusion and weight gain.

Contractant and relaxant properties of the female rabbit urethral submucosa

Isolated submucosal (lamina propria) preparations from the female rabbit urethra exhibited both contractant and relaxant properties. The nerve-mediated contraction to electrical field stimulation was adrenergic in nature, and both this response and the contraction induced by exogenous application of noradrenaline were blocked to a greater extent by alpha 2 than by alpha 1-adrenoceptor blocking agents. Vasoactive intestinal polypeptide was found to be a potent inhibitor of the noradrenaline-mediated contraction. Neuropeptide Y induced contraction of the preparation, but also inhibited the nerve-mediated contractant response. In noradrenaline-contracted preparations, electrical field stimulation induced a non-adrenergic, non-cholinergic relaxation. The maximum relaxant response was significantly greater when the preparations were contracted by clonidine than by noradrenaline. Abundant smooth muscle cells with no obvious connection to vessel walls were found in the submucosa, but to what extent the contractant and relaxant responses can be ascribed to vascular or non-vascular smooth muscle is not settled. The results indicate a non-uniform distribution of the peripheral nervous control within the wall of the female rabbit urethra. The demonstrated contractant and relaxant properties of the submucosal tissue might be of importance for urethral function.

Female incontinence: how much work-up is necessary?

Female incontinence at an age where it cannot be classified as a geriatric situation is a major problem for gynecologists and urologists. For several years both disciplines in Louvain have been working together in order to assess more precisely the indications for the different therapeutic possibilities and to evaluate results and failures of these therapies. This paper presents reflections on this experience together with comments on recent literature.