CNN-based diagnosis model of children's bladder compliance using a single intravesical pressure signal

Bladder compliance assessment is crucial for diagnosing bladder functional disorders, with urodynamic study (UDS) being the principal evaluation method. However, the application of UDS is intricate and time-consuming in children. So it'S necessary to develop an efficient bladder compliance screen approach before UDS. In this study, We constructed a dataset based on UDS and designed a 1D-CNN model to optimize and train the network. Then applied the trained model to a dataset obtained solely through a proposed perfusion experiment. Our model outperformed other algorithms. The results demonstrate the potential of our model to alert abnormal bladder compliance accurately and efficiently.

The Role of the Urinary Bladder in the Diagnosis of Abdominal Compartment Syndrome: A Prospective Study in Trauma Patients

Purpose The aim of this study was to evaluate the accuracy of bladder pressures in the diagnosis and management of abdominal compartment syndrome (ACS). Methods After Institutional Review Board (IRB) approval, nine operative abdominal trauma patients were prospectively studied over an 18-month period. Bladder pressures were compared to pressures obtained from intra-operatively placed electronic transducer located in the pelvis. Statistical analysis was performed using methods described by Bland and Altman. Results A Bland-Altman plot was used to assess the differences between bladder and transducer pressures. There was little agreement between the two methods at low (10-15 mmHg) and high (30-70 mmHg) pressures. At higher pressures, there was a notable difference between these two types of pressure. No patients required repeated operation. One patient died from severe traumatic brain injury. Conclusion Measurements obtained from the urinary bladder did not agree well with those obtained from within the peritoneal cavity. Furthermore, abdominal pressures greater than 20 mmHg did not show signs of ACS in this selected population, raising doubts about the utility of using abdominal pressures alone in the management of ACS.

Lateral Preoptic Area Neurons Activated by Angiotensin-(1-7) Increase Intravesical Pressure: A Novel Feature in Central Micturition Control

Central micturition control and urine storage involve a multisynaptic neuronal circuit for the efferent control of the urinary bladder. Electrical stimulation of the lateral preoptic area (LPA) at the level of the decussation of the anterior commissure in cats evokes relaxation of the bladder, whereas ventral stimulation of LPA evokes vigorous contraction. Endogenous Angiotensin-(1–7) [(Ang-(1–7)] synthesis depends on ACE-2, and its actions on binding to Mas receptors, which were found in LPA neurons. We aimed to investigate the Ang-(1–7) actions into the LPA on intravesical pressure (IP) and cardiovascular parameters. The gene and protein expressions of Mas receptors and ACE-2 were also evaluated in the LPA. Angiotensin-(1–7) (5 nmol/μL) or A-779 (Mas receptor antagonist, 50 nmol/μL) was injected into the LPA in anesthetized female Wistar rats; and the IP, mean arterial pressure (MAP), heart rate (HR), and renal conductance (RC) were recorded for 30 min. Unilateral injection of Ang-(1–7) into the LPA increased IP (187.46 ± 37.23%) with peak response at ∼23–25-min post-injection and yielded no changes in MAP, HR, and RC. Unilateral or bilateral injections of A-779 into the LPA decreased IP (−15.88 ± 2.76 and −27.30 ± 3.40%, respectively) and elicited no changes in MAP, HR, and RC. The genes and the protein expression of Mas receptors and ACE-2 were found in the LPA. Therefore, the LPA is an important part of the circuit involved in the urinary bladder control, in which the Ang-(1–7) synthetized into the LPA activates Mas receptors for increasing the IP independent on changes in RC and cardiovascular parameters.

Intravesical monitoring of intra-abdominal pressure after renal transplantation in children: A safety and feasibility study

IAH after RTX can threaten graft viability. This study aimed to assess the feasibility and safety of longitudinal IAP measurements as an IAH screening method in children after RTX. A cohort of eight children with a mean ± SD [range] age 9.6 ± 6.2 [2-17] years who underwent RTX and 18 control patients were evaluated between May 2017 and February 2018. We compared longitudinal IAP measurements using a Foley manometer to other clinical monitoring data. In total, 29 IAP measurements were performed in RTX patients and 121 in controls. The mean post-operative IAP was 7.4 ± 4.3 [1-16] mm Hg following RTX and 8.1 ± 3.7 [1-19] mm Hg in controls. We noted IAH in 9 (31%) of 29 IAP measurements after RTX and in 41 (34%) of 121 IAP measurements in controls. No graft dysfunction occurred in RTX patients despite elevated IAP values. The mean ± SD [range] time expenditure for IAP measurement was 2.1 ± 0.4 [0.6-3.2] minutes. No severe complications occurred during the IAP measurements. Analysis of longitudinal IAP measurements demonstrated that IAP measurement is safe and feasible in children recovering from renal transplantation in the PICU.

Oxytocin Reduces Intravesical Pressure in Anesthetized Female Rats: Action on Oxytocin Receptors of the Urinary Bladder

Urinary bladder dysfunction affects several people worldwide and shows higher prevalence in women. Micturition is dependent on the Barrington’s nucleus, pontine urine storage center and periaqueductal gray matter, but other brain stem areas are involved in the bladder regulation. Neurons in the medulla oblongata send projections to hypothalamic nuclei as the supraoptic nucleus, which synthetizes oxytocin and in its turn, this peptide is released in the circulation. We investigated the effects of intravenous injection of oxytocin (OT) on the urinary bladder in sham and ovariectomized rats. We also evaluated the topical (in situ) action of OT on intravesical pressure (IP) as well as the existence of oxytocin receptors in the urinary bladder. In sham female Wistar rats, anesthetized with isoflurane, intravenous infusion of OT (10 ng/kg) significantly decreased the IP (–47.5 ± 1.2%) compared to saline (3.4 ± 0.7%). Similar effect in IP was observed in ovariectomized rats after i.v. OT (–41.9 ± 2.9%) compared to saline (0.5 ± 0.6%). Topical administration (in situ) of 0.1 mL of OT (1.0 ng/mL) significantly reduced the IP (22.3.0 ± 0.6%) compared to saline (0.9 ± 0.7%). We also found by qPCR that the gene expression of oxytocin receptor is present in this tissue. Blockade of oxytocin receptors significantly attenuated the reduction in IP evoked by oxytocin i.v. or in situ. Therefore, the findings suggest that (1) intravenous oxytocin decreases IP due to bladder relaxation and (2) OT has local bladder effect, binding directly in receptors located in the bladder.

Modulation of Bladder Wall Micromotions Alters Intravesical Pressure Activity in the Isolated Bladder

Micromotions are phasic contractions of the bladder wall. During urine storage, such phasic activity has little effect on intravesical pressure, however, changed motile activity may underlie urodynamic observations such as detrusor overactivity. The potential for bladder motility to affect pressure reflects a summation of the overall movements, comprising the initiation, propagation, and dissipation components of micromotions. In this study, the influence of initiation of micromotions was investigated using calcium activated chloride channel blocker niflumic acid, and the effect of propagation using blockers of gap junctions. The overall bladder tone was modulated using isoprenaline. Isolated tissue strips and whole bladder preparations from juvenile rats were used. 18β-glycyrrhetinic acid was used to block gap junctions, reducing the amplitude and frequency of micromotions in in vitro and ex vivo preparations. Niflumic acid reduced the frequency of micromotions but had no effect on the amplitude of pressure fluctuations. Isoprenaline resulted in a reduction in pressure fluctuations and a decrease in pressure baseline. Using visual video data analysis, bladder movement was visible, irrespective of lack of pressure changes, which persisted during bladder relaxation. However, micromotions propagated over shorter distances and the overall bladder tone was reduced. All these results suggest that phasic activity of the bladder can be characterised by a combination of initiation and propagation of movement, and overall bladder tone. At any given moment, intravesical pressure recordings are an integration of these parameters. This synthesis gives insight into the limitations of clinical urodynamics, where intravesical pressure is the key indicator of detrusor activity.

Comparing a novel hand held device (Peritron+) to standard urodynamics in measuring intravesical pressure

AIMS

Peritron+ is a new handheld device, which can be attached to a urethral catheter to measure intravesical pressures (Pves). The goal of this study was to assess if Pves recorded by standard urodynamics (UDs) are comparable to those recorded by the Peritron+.

METHODS

Patients with voiding dysfunction and an indication for UD underwent measurement of Pves with nonvideo UD and Peritron+. Pves were recorded at volumes of 50, 100, and 200 mL for the supine and sitting positions. A failure of the Peritron+ was considered to be a discrepancy of Pves values >3 cmH₂ O between Peritron+ and UD recordings. Two-way ANOVA was used to assess for statistical significance. P-values < 0.05 were considered significant.

RESULTS

Ten female patients, mean age 51 years old, were enrolled in the study. The difference in Pves measurements between Peritron+ and UD were ≤3 cmH₂ O at all bladder volumes measured in a supine and sitting positions. There were no adverse events and there were no malfunctions of the Peritron+ device during the study.

CONCLUSIONS

Peritron+ handheld device accurately assessed Pves at different intravesical volumes when compared to UD measurements. The Peritron+ is a simple and safe device, which can be used in the office by a clinician and at home by a patient to monitor Pves and help to select patients who may require standard UD re-evaluation. This will be a valuable tool in managing patients with neurogenic and nonneurogenic bladders who are at a risk of upper urinary tract deterioration.

Correlation of Xiphopubic Distance, Body Weight, Height and Body Mass Index with Intravesical and Abdominal Initial Resting Pressures in Urodynamic Testing in the Sitting Position

OBJECTIVES

To compare the initial resting intravesical pressure (p_ves ) and abdominal pressure (p_abd ) in the sitting position with the typical range of values, to assess the correlation between such pressures and patient xipho-pubic distance, body weight, height and body mass index (BMI), and to estimate if xipho-pubic distance can be a guide to interpret initial resting pressures in urodynamic testing.

METHODS

Women with lower urinary tract symptomatology referred for urodynamic testing were consecutively enrolled in a prospective study. Conventional cystometry was done following "good urodynamic practices". The correlation between initial resting p_ves and p_abd and xipho-pubic distance, body weight, height and BMI were studied using simple and multiple linear regression analysis. Statistical significance was defined as P < 0.05.

RESULTS

One hundred women aged (mean ± SD) 59.2 ± 13.3 were studied. There was a significant correlation between both p_ves and p_abd , and xipho-pubic distance, body weight and BMI and no correlation with height. Over the multiple analysis, xipho-pubic distance and body weight correlated independently with p_ves ; body weight correlated independently with p_abd . Three patients had p_ves and/or p_abd out of typical range, with BMIs values of 18.48, 18.72 and 35.81 kg/m² . There was a wide range of difference between xipho-pubic distance and initial resting pressures.

CONCLUSIONS

Out of range initial resting pressures occur in underweight (or close to) or severely obese patients. Xipho-pubic distance and body weight correlated independently with p_ves . Body weight correlated independently with p_abd . Xipho-pubic distance cannot be a guide to interpret the initial resting pressures.

Distigmine Bromide Produces Sustained Potentiation of Guinea-Pig Urinary Bladder Motility by Inhibiting Cholinesterase Activity

Distigmine is a cholinesterase (ChE) inhibitor used for the treatment of detrusor underactivity in Japan. Distigmine's pharmacological effects are known to be long-lasting, but the duration of its effect on urinary bladder contractile function has not been fully elucidated. The present study aimed to determine these effects in relation to the plasma concentrations of distigmine and its inhibition of ChE activities in blood, plasma, and bladder tissue. Intravesical pressures were recorded in anesthetized guinea-pigs for 12 h after the intravenous administration of saline or distigmine (0.01-0.1 mg/kg). Plasma distigmine concentrations were measured by liquid chromatograph-tandem mass spectrometry (LC-MS/MS), while ChE activities were assayed using 5,5'-dithiobis(2-nitrobenzoic acid). Distigmine (0.1 mg/kg) significantly increased the maximum intravesical pressure at micturition reflex for 12 h post-administration. In contrast, plasma distigmine was only detectable for 6 h post-administration in these animals and a one-compartment model calculated an elimination half-life of 0.7 h. However, bladder and blood acetylcholinesterase activities were significantly inhibited for 12 h after distigmine administration, although plasma ChE activities were not affected. The pharmacodynamic effects of distigmine thus persisted after its elimination from the circulation, indicating that it may bind to bladder acetylcholinesterase, producing sustained enzyme inhibition and enhancement of bladder contractility.

Management of ovarian hyperstimulation syndrome with abdominal compartment syndrome, based on intravesical pressure measurement

There are few reports on abdominal compartment syndrome that are caused by ovarian hyperstimulation syndrome (OHSS). Here, a case of a 29 year old woman is reported in which intravesical pressure measurement was useful in the management of severe OHSS that had been complicated by abdominal compartment syndrome. The patient's urinary output and general condition did not improve after the initial treatment. The woman's intra-abdominal pressure was evaluated indirectly, based on her intravesical pressure, and was found to be significantly elevated. The patient's urinary volume increased after a 14 mm Hg decrease in the intravesical pressure was achieved by the drainage of ascitic fluid. Intravesical pressure measurement was useful in the management of the general condition of this patient with OHSS.

Does pharmacological activation of 5-HT1A receptors improve urine flow rate in female rats?

The role of 5-HT1A receptors in regulating voiding functions remains unclear, particularly regarding the urine flow rate (UFR) during voiding. This study examined the effects of 5-HT1A receptors on regulating urethral functions in female rats and investigated underlying modulatory mechanisms. Intravesical pressure (IVP), external urethral sphincter-electromyography (EUS-EMG), and UFR were simultaneously recorded during continuous transvesical infusion to examine the effects of a 5-HT1A receptor agonist (8-OH-DPAT) and antagonist (WAY-100635) on bladder and urethral functions. In addition, this study evaluated the independent roles of urethral striated and smooth muscles in the UFR in rats after a neuromuscular blockade (NMB) treatment and bilateral hypogastric nerve transection. Our results revealed that 8-OH-DPAT significantly increased the maximal UFR but reduced the mean UFR. This discrepancy may be because 8-OH-DPAT markedly increased the maximal UFR during the initial segment of the flow duration and subsequently induced an approximately zero level of long oscillatory waves during the remaining flow duration. Thus the mean UFR was reduced because of the prolonged approximately zero level of the UFR. However, paralyzing the EUS with an NMB agent, 8-OH-DPAT, significantly increased the maximal and mean UFRs because the prolonged zero level of the oscillatory UFR did not continue. These results support the hypothesis that the increased UFR in female rats during voiding is due to the induction of urethral smooth muscle relaxation by 8-OH-DPAT. This paper provides a detailed understanding of the role of 5-HT1A receptors in controlling the UFR in female rats.

Acupuncture at homotopic acupoints exerts dual effects on bladder motility in anesthetized rats

BACKGROUND

In Chinese medicine, dual effects on target organs are considered a primary characteristic of acupoint. Acupoints may be classified as heterotopic or homotopic in terms of spinal segmental innervation: homotopic acupoints contain afferent innervation in the same segment from which efferent fibers innervate target visceral organs, and heterotopic acupoints utilize different spinal segments to innervate target visceral organs than the segment receiving the afferent signal. It is well-known that dual effects of acupuncture on the bladder can be generated based on different states of the bladder, however, the dual effects of single acupoint stimulation and acupoint site-specificity (homotopic acupoints and heterotopic acupoints) on the bladder have yet to be investigated.

METHODS

Twenty Sprague-Dawley rats were anesthetized and the intravesical pressure was measured via a manometric balloon inserted into the bladder. The acupuncture needle was separately inserted to a depth of 4 mm at the acupoints RN1 (Huiyin), RN3 (Zhongji), BL28 (Pangguangshu), BL32 (Ciliao), RN2 (Qugu) or BL23 (Shenshu), and manually rotated right then left with a frequency of 2 Hz for 1 min. Following acupuncture stimulation, bladder pressure was recorded and compared against the pre-stimulation measurements.

RESULTS

During the bladder's active state, manual acupuncture (MA) at RN1, RN3, BL28, BL32 or RN2 inhibited bladder motility (P < 0.01). In the static bladder, MA at RN1, RN3, BL28, BL32, RN2 or BL23 increased bladder motility (P < 0.01).

CONCLUSIONS

MA at homotopic acupoints may produce dual effects on bladder motility: inhibiting bladder motility when in an active state and enhancing bladder motility when in a static state.

Influence of serotonergic mechanisms on the urine flow rate in male rats

This study extensively examined the role of a 5-HT(1A) receptor in controlling voiding function in anesthetized male rats. A simultaneous recording of the intravesical pressure (IVP), external urethral sphincter (EUS)-electromyography (EMG), and urine flow rate (UFR) during continuous cystometry was used. 8-Hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT), a 5-HT(1A) receptor agonist, significantly improved the voiding efficiency, as detected by increases in the evoked contraction amplitude, EUS burst period, and silent period, and decreases in the volume threshold, pressure threshold, and residual volume. Interestingly, the UFR during voiding was reduced by 8-OH-DPAT, as evidenced by decreases in the maximal UFR and mean UFRs of the voiding period, spike duration, and interspike interval. Conversely, treating rats with WAY-100635, a 5-HT(1A) antagonist, produced effects opposite to those produced by 8-OH-DPAT. These findings suggest that 8-OH-DPAT improved the voiding efficiency by enhancing the detrusor contractile ability and prolonging EUS burst period, which would compensate for the lower UFR, resulting from urethral smooth muscle contractions and longer EUS silent periods during voiding. The present study contributes to our understanding of the role of 5-HT(1A) receptors in controlling the urine flow rate in male rats.

Sexually dimorphic urethral activity in response to pharmacological activation of 5-HT1A receptors in the rat

In this study, we examined the possibility that 5-HT1A receptors may underlie sexually dimorphic mechanisms affecting the regulation of urethral functions in anesthetized rats. Simultaneous recordings of intravesical pressure under isovolumetric conditions, external urethral sphincter-electromyography, and urethral perfusion pressure were used to examine the effects of a 5-HT1A receptor agonist [8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT)] and antagonist (WAY-100635) on bladder and urethral functions. This research also evaluated the effects of 8-OH-DPAT and α-bungarotoxin (a neuromuscular blockade agent) on urethral continence using leak point pressure testing, and the distribution of 5-HT1A receptors in the lower urinary tract was assessed by immunohistochemistry. The serotonergic mechanism that controls the urinary bladder and external urethral sphincter-electromyography activity showed no significant sexual differences, but urethral activity in urethral perfusion pressure and leak point pressure values exhibited some sexual differences. 8-OH-DPAT enhanced urethral pressure during continence in rats of both sexes, but the drug elevated the pressure during voiding in male rats and reduced it in female rats. The distribution of 5-HT1A receptors in the spinal cord also showed some sexual differences. The present study contributes to our understanding of the role of 5-HT1A receptors in physiological and immunohistochemical properties of urethral smooth muscle in rats of different sexes. These findings may be a basis for the future development of pharmacotherapies for stress urinary incontinence in men.

The validation of a functional, isolated pig bladder model for physiological experimentation

Characterizing the integrative physiology of the bladder requires whole organ preparations. The purpose of this study was to validate an isolated large animal (pig) bladder preparation, through arterial and intravesical drug administration, intravesical pressure recording, and filming of surface micromotions. Female pig bladders were obtained from the local abattoir and arterially perfused in vitro. Arterial and intravesical pressures were recorded at varying volumes. Bladder viability was assessed histologically and by monitoring inflow and outflow pH. Arterial drug administration employed boluses introduced into the perfusate. Intravesical administration involved slow instillation and a prolonged dwell-time. Surface micromotions were recorded by filming the separation of surface markers concurrently with intravesical pressure measurement. Adequate perfusion to all bladder layers was achieved for up to 8 h; there was no structural deterioration nor alteration in inflow and effluent perfusate pH. Arterial drug administration (carbachol and potassium chloride) showed consistent dose-dependent responses. Localized movements (micromotions) occurred over the bladder surface, with variable correlation with fluctuations of intravesical pressure. The isolated pig bladder is a valid approach to study integrative bladder physiology. It remains viable when perfused in vitro, responds to different routes of drug administration and provides a model to correlate movements of the bladder wall directly to variation of intravesical pressure.

Real-Time Monitoring of Blood Flow and Intravesical Pressure in the Rat Bladder

OBJECTIVES

Because there is little information available about blood flow in the voiding cycle of the bladder, we performed a study in which we simultaneously monitored blood flow and intravesical pressure during the micturition cycle in a rat model.

METHODS

Approximately 300 g male Wistar rats were used in this study. Cystometric studies were performed according to our previous report, and simultaneously blood flow was monitored.

RESULTS

Before the micturition reflex occurred, a significant increase in bladder blood flow was observed, and this increased blood flow continued during the micturition reflex. Under the maximum contraction pressure, blood flow rapidly decreased (within 10% compared to the max level). This low level of blood flow continued for more than half a minute.

CONCLUSION

Our data indicated that the blood flow in the bladder was dynamically changed during voiding. This technique may represent a strong tool to investigate bladder function under drug administrations and/or pathophysiological conditions.