Norepinephrine inhibits the pelvic pressure increase in response to flow perfusion

PURPOSE: We evaluated the effects of norepinephrine on transport pressures in the normal upper urinary tract of the pig during increasing perfusion rates. MATERIALS AND METHODS: Anesthetized Danish landrace Yorkshire pigs weighing 38 to 40 kg were studied. Transparenchymally 2, 6Fr catheters were introduced into the left renal pelvis for pressure measurements and perfusion, respectively. An ultrasonic flow probe was inserted around the left renal artery to record blood flow. A 10Fr catheter was placed transurethrally for bladder drainage and the bladder was maintained empty during the entire study. In the 5 group 1 pigs the pelvic pressure increase was examined at increasing perfusion rates of the renal pelvis (2, 4, 6, 8, 10 and 15 ml per minute) in response to endoluminal administration of increasing concentrations of norepinephrine (0, 5, 50 and 100 microg/ml) in saline. In the 5 group 2 pigs the pressure flow study was also done 4 times per animal using isotonic saline. RESULTS: Endoluminal norepinephrine had a dose dependent effect on the pressure flow relationship. Perfusion with 5 and 50 microg/ml norepinephrine caused a delayed increase and a decrease in pelvic pressure in response to increasing flow rates, whereas perfusion with 100 microg/ml norepinephrine significantly inhibited and almost eliminated the pressure increase at all perfusion rates compared with saline perfusion. Importantly there were no changes in blood pressure, the heart rate or renal arterial blood flow. In group 2 perfusion with isotonic saline resulted in the same pressure response to increasing flow rates each time. CONCLUSIONS: Endoluminal administration of norepinephrine caused a dose dependent inhibition on the pressure phases of the pressure flow relationship of the upper urinary tract in pigs. No systemic changes were observed. These observations may provide a useful adjuvant treatment strategy for upper urinary tract stone treatment and endoscopy.     

Does perfusion equal diuresis in the upper urinary tract?

Pressures occurring in the upper urinary tract during perfusion and diuresis were compared in an unsedated dog preparation. Perfusion pressures were significantly higher, suggesting that a product of diuresis actively reduces upper tract tone.     

Significance of the antireflux valve for upper urinary tract pressure. An experimental study in patients with urinary diversion via a continent ileal reservoir.

When bladder substitution is required, a low pressure receptacle and an antireflux valve with low resistance to flow is essential for preservation of the upper urinary tract. The aim of this study was to evaluate whether these criteria are attained in the continent ileal reservoir used for urinary diversion. The investigations were performed in six patients more than one year after supravesical urinary diversion via a continent ileal reservoir. The pressure was recorded simultaneously both in the afferent loop and in the reservoir during filling of the reservoir. There was a slow parallel increase in the basal pressure in the reservoir and the afferent loop. Pressure waves appeared sometimes simultaneously and sometimes in only one compartment at a time. Only during short periods of time did the pressure exceed 25 cm of water. The frequency of pressure waves increased with increased filling of the reservoir. The "total pressure" was larger in the reservoir than in the afferent loop. It is the antireflux valve which prevents pressure rises in the reservoir from being conveyed to the upper urinary tract. The resistance to urinary flow was moderate.     

Ureteral pressure flow studies in difficult diagnostic problems.

Before a ureteral operation is undertaken for dilated, non-refluxing ureters it is essential to determine whether obstruction is present, since an operation is unnecessary and can be hazardous if there is no obstruction or infection. Obstruction is most accurately diagnosed by perfusing the upper tract at a known flow rate and measuring the resulting pressure. This test was performed on 5 patients in whom there was doubt as to the presence of obstruction from the radiographic evidence. In 4 of the 5 patients low pressure was found, the obstruction was excluded and an operation was avoided. In the fifth patient the obstruction was confirmed and relieved. The pressure flow test is useful in the diagnosis or exclusion of obstruction in the upper urinary tract.     

The effects of double J stenting on unobstructed ureters. An experimental and clinical study

Upper tract pressure flow studies in four clinically unobstructed ureters with double J stents in situ indicated that urinary flow occurred mainly around the stent and that there was significant vesicorenal pressure transmission. This study examined the dynamics of ureteric urinary flow and morphological effects consequent upon stenting a ureter in vivo. In a porcine model, ureteric intubation caused a rise in intrapelvic pressures, hydroureter, vesicorenal reflux and generalised thickening of the ureteric wall with characteristic histological changes in the urothelium. These findings suggest that double J stents may compromise urinary drainage when ureteric obstruction is not present, urging caution in their use in the damaged, unobstructed upper urinary tract.     

Relationships between lower urinary tract symptoms and bladder outlet obstruction: Results from the ICS-“BPH” Study

Despite the lack of evidence in the literature for close relationships between lower urinary tract symptoms and bladder outlet obstruction, the majority of urologists rely on symptomatology when selecting patients for prostatic surgery. We investigated the relationships between a wide range of lower urinary tract symptoms from the ICSmale questionnaire and the results of urodynamic pressure and flow studies. We evaluated 933 patients with lower urinary tract symptoms suggestive for bladder outlet obstruction from 12 countries who participated in the ICS-“BPH” study with the ICSmale questionnaire and urodynamic pressure and flow studies. Spearman rank correlation coefficients were obtained between symptoms and measures of bladder outlet obstruction. There was little or no correlation between a wide range of symptoms and the results of free uroflowmetry and pressure and flow studies. From symptoms alone, it is not possible to diagnose bladder outlet obstruction. Pressure and flow studies and symptom profiles measure different aspects of the clinical condition that should be viewed separately in the evaluation and treatment decision of the patient presenting with lower urinary tract symptoms. Neurourol. Urodynam. 17:99–108, 1998. © 1998 Wiley-Liss, Inc.     

A modified Whitaker test (upper urinary tract videourodynamics) using for evaluating complex upper urinary tract reconstruction surgical effect

BackgroundTo evaluate the feasibility and effect of upper urinary tract videourodynamics in complex reconstructed upper urinary tract.MethodsFrom January 2016 to December 2018, patients who underwent complex upper urinary tract reconstruction and received upper urinary tract videourodynamics were included in the study. The modified Whitaker test was performed at 3 months after operation. The relative pelvic pressure was defined as the pelvic pressure minus the bladder pressure. Based on the flow rate, the test was divided into physiological phase and high flow phase. The results of pressure and image were classified into 3 types. Successful nephrostomy removal was defined as no symptoms and improved or stable hydronephrosis.ResultsA total of 12 patients who underwent complex upper urinary tract reconstruction received modified Whitaker test. All tests were successfully completed without adverse reactions. The relative pelvic pressure of 3 patients kept steady near the baseline throughout the examination and was classified into type 1. The pelvic pressure of 7 patients increased as the perfusion continued, and the relative pressure dropped to relative low level due to the peristalsis of ureter (type 2). The pressure of 2 patients increased along with increasing perfusion speed, and the relative pelvis pressure could easily reach 15 cmH2O. The peristalsis of ureter disappeared or appeared very weakly on the video record (type 3). Patients in type 1 (3 cases) and type 2 (7 cases) groups were allowed to remove the nephrostomy tube immediately. Patients in type 3 group needed to keep the nephrostomy for close follow up, and the tubes were removed 2 weeks and 4 weeks after the examination, respectively. None of the 12 patients received further treatment for recurrent symptoms and exacerbation of hydronephrosis.ConclusionsThe modified Whitaker test is initially safe and feasible in postoperative evaluation of complex upper urinary tract reconstruction surgery. Detailed results can provide more evidence to judge whether nephrostomy tube could be removed safely.     

Mechanism of upper tract dilatation in patients with thick walled bladders, chronic retention of urine and associated hydroureteronephrosis

The mechanism of upper tract dilatation in patients with obstructive uropathy associated with thick walled trabeculated bladders and painless retention of urine has been determined in 9 cases by simultaneous measurement of renal pelvic and bladder pressures under baseline conditions and after administration of different stresses to the urinary tract. Under basal conditions no pelvic pressure increase was observed during detrusor contraction or other alteration of lower urinary tract pressure. However, after the flow in the upper tract was increased by oral water load, intravenous furosemide or direct pelvic perfusion, pelvic pressures were markedly elevated and reflected accurately any change in intravesical pressure. Under such conditions, pelvic pressures frequently exceeded 40 cm. water. These observations provide an explanation for the increasing size of the upper tract and a clarification of the mechanism whereby renal function might gradually deteriorate in these patients.     

Sensitivity of 131I-hippuran diuresis renography and pressure flow study (Whitaker test) in upper urinary tract obstruction

Diuresis renography and pressure flow studies were performed in 14 patients with unilateral hydronephrosis. Based upon the results of intravenous pyelography, typical symptomatology, and the outcome of surgical treatment, all patients were found to have upper urinary tract obstruction. It was therefore possible to calculate the sensitivity of the two tests. Obstruction was found at the pressure flow studies in 7 of 14 patients (50%), while an obstructive pattern was found at diuresis renography in 12 of 13 patients (92%). Due to a very low glomerular filtration rate, diuresis renography was equivocal in 1 case. Based upon these results, diuresis renography seems to be superior to pressure flow studies in cases with upper urinary tract obstruction.     

Measurement of intrapelvic peristaltic activity in the diagnosis of equivocal upper urinary tract obstruction

Direct measurement of upper urinary tract dynamics during perfusive stress is an accepted method of investigating the dilated upper urinary tract when a clear diagnosis of obstruction cannot be refuted by indirect radiological or renographic means. Transparenchymal renal puncture for intrapelvic pressure transduction has become an accepted technique over the last 15 years, well-defined “standard” fluid stresses being determined to uncover covert obstructions with strict criteria for the determination of such a state. These antegrade perfusion/pressure tests do not, however, take into account the role of upper tract peristalsis, an important factor for the promotion of renal drainage in multicalyceal animals. Fifteen patients with equivocal upper urinary tract obstruction had their upper urinary tract dynamics determined prospectively by a modification of the standard Whitaker test, results of these studies being compared with measurements of pelvic peristalsis and baseline intrarenal pressure made by using an intrapelvic microtransducer-tipped catheter interfaced to a computerised recording system. This system enabled the measurement of pelvic dynamics in various postures without the necessity for transducer rezeroing. Six patients showed abnormalities of pelvic peristaltic activity indicative of the obstructed upper tract, only three of whom had unequivocally obstructed Whitaker tests. All obstructed patients had accentuation of their peristaltic abnormalities in the sitting position, underlining the importance of performing direct dynamic measurements in a physiological position. We have found that measurement of pelvic peristaltic activity as well as baseline intrapelvic pressure during perfusion is important for the delineation of the equivocally obstructed kidney, suggesting that the antegrade perfusion/pressure test should be modified to allow more physiological study of renal outflow dynamics.     

Endoluminal isoproterenol reduces renal pelvic pressure during semirigid ureterorenoscopy: a porcine model

OBJECTIVE

To investigate the effects on the pressure‐flow relation of renal pelvic pressure during semirigid ureterorenoscopy and endoluminal perfusion of isoproterenol (ISO) 0.1 µg/mL, with emphasis on local effects and cardiovascular side‐effects, as topically administered ISO effectively and dose‐dependently causes relaxation of the upper urinary tract in pigs with no concomitant cardiovascular side‐effects.

MATERIALS AND METHODS

In anaesthetized female pigs (60 kg), 16 macroscopically normal upper urinary tract systems were subjected to ureterorenoscopy. Via a subcostal incision a 6‐F catheter was placed in the renal pelvis for pressure measurements, and a semirigid ureteroscope (7.8 F) was inserted retrogradely in the renal pelvis, through which the pelvis was perfused. The blood pressure and heart rate were recorded. The increase in renal pelvic pressure was examined with increasing flow rates (0, 4, 8, 12, 16, 25 and 33 mL/min) with saline alone or saline + ISO 0.1 µg/mL. Perfusion was initiated on the left side, with randomization for adding ISO or not. Thereafter perfusion was done on the right side as a control in each pig. The surgeons were unaware of whether ISO was added or not.

RESULTS

The mean (sd ) baseline pelvic pressures in the saline and ISO group were 28 (7.1) and 25 (9.8) mmHg, respectively, with no significant difference (P = 0.079). Endoluminal perfusion with ISO significantly inhibited the pelvic pressure increase to perfusion at all perfusion rates. The pressure‐flow relation was linear; the maximum relaxation (27%) was obtained at 4 mL/min, from 52 to 38 mmHg during saline alone and ISO 0.1 µg/mL perfusion, respectively. The mean blood pressure did not change significantly (P = 0.330). The mean (sd ) heart rate in the saline and ISO group were 109 (4.5) and 97 (2.1) beats/min, respectively (P < 0.001), i.e. a markedly greater rate in the saline than in the ISO group.

CONCLUSION

The pressure‐flow relation during semirigid ureterorenoscopy was linear. ISO 0.1 µg/mL in saline significantly reduced the pressure‐flow relation during semirigid ureterorenoscopy in this porcine model. ISO might be a potential additive to the irrigation fluid during upper urinary tract endoscopic procedures, minimizing pressure increases due to irrigation and manipulation.     

Combined urodynamic insufficiency in patients with an infravesical obstruction

Functional activity of the lower and upper urinary tract was examined in 169 patients with infravesical obstruction and in 20 controls. Combined investigation included: radioisotope uroflowmetry, retrograde cystomanometry, urethrosphincterometry, miction videocystourethrography, excretory urography, radioisotope renography, pharmacorenography, dynamic nephroscintigraphy and renal angiography. An analysis of lower urinary urodynamic findings has demonstrated stages as an important regularity in the development of functional lower urinary disturbances. As a result, a standard system has been evolved for the assessment and classification of stages in chronic lower-urinary urodynamic disorders. Four stages are identified in the classification. Evaluation of upper-urinary urodynamics in the same 169 patients with lower urinary tract disorders of varying severity demonstrated that upper urinary functional parameters become worse as lower urinary parameters deteriorate, but there is no strict correlation between those. A systematic study of the pattern of combined disorders of the lower and upper urinary tract has made it possible to develop a standard system for the assessment and classification of stages of combined urodynamic insufficiency, with 4 stages identified. The use of this system improves objective assessment of the severity of patient's condition and specifies indications for surgical treatment of infravesical obstructions.     

Place de la cystomanométrie à colonne d’eau dans l’exploration des vessies neurologiques chez l’enfant

IntroductionDescribe the technique of water column cystometry in children and investigate the existence of a correlation between the leak point pressure measured by this process and the alteration of the upper urinary tract.Subjects and methodsDuring the period 2009 - 2012, 48 children with neurogenic bladder secondary to myelodysplasia, aged between 2 and 15 years at the first consultation and have not received a specific medical treatment for bladder sphincter dysfunction or surgery on the urinary tract, have been explored by a clinical examination, ultrasound of the urinary tract, retrograde urethral-cystography and a water column cystomanometry without using a device of urodynamic study.ResultsThe average age of the series was 6 years old. The upper urinary tract dilatation was present in 30 cases and vesicoureteral reflux in 22 cases. Of all the 28 cases that had a leak point pressure> 40 cm of water dilatation of the upper urinary tract was present in 24 cases and vesicoureteral reflux in 19 cases.DiscussionThe results obtained show that there is a correlation between the elevation of the leak point pressure above 40 cm of water and alteration of the upper urinary tract. They are similar to those found in the literature.ConclusionThis study shows that the water column cystometry is an effective alternative that provides a reliable measure of the leak point pressure.     

The Whitaker test: experimental analysis in a canine model of partial ureteric obstruction

The Whitaker test has been described as a means of reaching a diagnosis in equivocal upper urinary tract obstruction, but there has been conflicting evidence regarding the validity of this test. The present study assesses the reliability of the test in an experimental model which creates an accurate and predetermined degree of partial obstruction of the ureter. The Whitaker test was performed using the standard perfusion rate of 10 ml./min. in male adult dogs using a long-term indwelling renal intrapelvic cannula before and after application of ureteric obstruction, and after one month. Control animals underwent a sham procedure. Results of in vivo and in vitro perfusion studies were compared. Perfusion studies at multiple flow rates were also performed. The Whitaker test reliably detected the presence of ureteric obstruction and the degree of partial obstruction could be determined. Multiple flow rate studies did not significantly improve test results. Provoked pressures in the highest grade of obstruction were less than expected and this may be due to pyelovenous reflux.     

The value of ultrasound scanning of the upper urinary tract in patients with bladder outlet obstruction

Ultrasound scanning of the upper urinary tract enables a urologist to allocate a degree of urgency for surgery when upper tract dilatation is present. We have studied whether other assessments of bladder outlet obstruction could eliminate this investigation. The study group comprised 223 consecutive patients who had ultrasound scans for bladder outlet obstruction. Estimation of urea, creatinine, residual urine and flow rate could not predict the presence of upper tract dilatation and it was concluded that ultrasound scanning of the upper tracts should continue to be used as a means of deciding how urgently a patient requires prostatic surgery.     

Management of the obstructed urinary tract associated with neurogenic bladder dysfunction

The child with neurogenic bladder dysfunction may suffer from lower urinary tract obstruction, which, if untreated, can result in upper urinary tract deterioration. It is prudent to identify those newborns and infants who are at risk for upper urinary tract deterioration and advise an appropriate treatment protocol. In order to identify those children at risk, a thorough examination is required, along with appropriate upper urinary tract imaging studies and urodynamic assessment of the bladder. Infants and children at risk for upper tract deterioration are those who have intermittent or continuous detrusor pressure elevation above 40 cm H2O. We have identified the safe period, which is the time during which the bladder remains at a pressure lower than 40 cm H2O. Our management protocol for each child is individualized and based on increasing the safe period. The safe period can be increased with a combination of intermittent catheterization, administration of medications, and, in some cases, surgical reconstruction. With compulsive evaluation and intensive management, many of the previous upper urinary tract changes associated with the obstructed neurogenic bladder can be averted. With the above factors in mind, we have defined the period of bladder filling and storage where the pressure is below 40 cm H2O as the safe period. The ideal bladder for maintenance of normal upper tracts would have a long safe period and low voiding pressure. Our treatment protocol for the neurogenic bladder is therefore dependent on identifying those children who have very short or nonexistent safe periods. These are the children who are at risk for upper tract deterioration.     

Urodynamic studies of the upper urinary tract. I. Introduction and diagnosis of the obstruction

Present experience precludes any assertion as to what a urodynamic exploration of the upper urinary tract exactly comprises, and what the fundamental indications are, despite the many attempts already made, which the author recalls. After establishing the conceptual difference between obstruction and stasis, the author goes on to analyze the existing methods for identifying the existence of an obstruction in cases of chronic dilatation. Noninvasive methods, intravenous urography, diuretic urography, conventional and diuretic renography and analysis of the parenchymal transit time, are all probably successful in establishing the existence of an obstruction in 85 per cent of cases of chronic dilatation of the upper urinary tract; but these methods cannot be used to quantify the obstruction, or even identify it in certain specific cases. In order to quantify the obstruction, recourse must be had to invasive methods, and more particularly, in view of the limitations of basal and diuretic pyelomanometry, to combined pressure/flow studies. The author analyzes the two possibilities open for the application of these procedures (constant flow perfusion, or perfusion with a constant pressure) together with their advantages and drawbacks.     

排尿功能障碍致上尿路损害的机制及防治策略

排尿功能障碍导致的上尿路损害在泌尿外科临床常见,严重威胁患者生命。尿动力学研究发现3．92kPa（1cmH2O=0．098kPa）是上尿路损害的膀胱压临界值,达到或超过安全压仍继续储尿是导致上尿路损害的最重要原因。因此,无论采用何种治疗手段,将膀胱压降至安全压以下,在安全容量前排空膀胱是保护上尿路的根本原则。     

Value of routine evaluation of the voiding phase when performing urodynamic testing in women with lower urinary tract symptoms

PURPOSE: Lower urinary tract symptoms in women are often evaluated by cystometrography. We only assessed the bladder response to filling and not the impact of abnormal voiding, which is known to cause lower urinary tract symptoms. We determined the prevalence of voiding abnormalities in women with lower urinary tract symptoms and compared cystometrography to cystometrography plus voiding pressure flow study for evaluating this condition. We also determined whether storage or voiding symptoms predicted abnormal voiding. MATERIALS AND METHODS: We reviewed the records of 134 women who underwent video urodynamics with cystometrography and voiding pressure flow study to evaluate lower urinary tract symptoms. Patients with a history of neurological disease, grade 4 pelvic prolapse or a primary complaint of stress incontinence were excluded from study. All participants completed an American Urological Association symptom index and scores were subclassified as total, storage and voiding. A diagnosis was made in each case based on cystometrography findings, while any additional diagnoses when applicable were based on the voiding pressure flow study. Symptom scores were compared in women in whom the voiding study did and did not add information. RESULTS: Mean patient age was 53.1 years (range 19 to 90). Voiding studies added information in 44 cases (33%), including dysfunctional voiding in 16, obstruction due to a moderate cystocele in 6, primary bladder neck obstruction in 6, external-detrusor sphincter dyssynergia as the initial presentation of neurological disease in 5, obstruction after incontinence surgery in 3, urethral stricture in 3, post-void contraction mimicking symptoms in 2, impaired contractility in 2 and an obstructing urethral diverticulum in 1. A total of 32 patients (24%) did not void during the study. Those with voiding abnormalities had higher total and voiding but similar storage symptom scores (23.1 versus 18.5, 12.3 versus 8.0 and 10.8 versus 10.5 points, p = 0.0008, 0.0001 and 0.58, respectively). CONCLUSIONS: Women with lower urinary tract symptoms may have voiding abnormalities that are missed by cystometrography only. Voiding studies are useful for properly diagnosing and treating such cases. Women with abnormal voiding seem to have more severe voiding symptoms than those without such abnormalities. Occult neurological disease may also be identified in patients with lower urinary tract symptoms and voiding abnormalities.     

Assessment of obstruction in adult ureterocele by means of color Doppler duplex sonography

AIM: The purpose of this study is to present a method for identifying a ureteral obstruction in unilateral orthotopic ureterocele by means of conventional sonography and color Doppler duplex sonography. We focus on the measurement of the ureterocele dimensions, the degree of dilation it causes to the ipsilateral upper urinary tract, the registration of urine out-flow from the ureteral orifice into the bladder and its spectral analysis. MATERIAL AND METHOD: Over 2 years at our institutions, 8 adult patients (7 women, 1 man) were diagnosed as having a single system orthotopic ureterocele. Four of them presented with lumbar pain, dysuria and recurrent urinary tract infections, while the remainder were asymptomatic and diagnosed accidentally. The diagnosis was based on serial sonography of the upper and lower urinary tract confirmed by intravenous pyelography and cystoscopy. We also performed color Doppler duplex sonographic evaluation of the urine jets ejected from both ureteral orifices into the bladder. Using the flow spectral study we analyzed the waveforms and measured their duration and flow rate. The study was completed with a comparative analysis of the data obtained from both ureteral orifices. RESULTS: Cystic dilation of the lower ureteric extremity into the bladder was presented in all cases. Upper urinary tract dilation, of various grades, was present in 4 of 8 patients. Differences in urine jets between those derived from the ureterocele and those from the healthy contralateral ureteral orifice were significant in those patients with dilation of the upper urinary tract. The differences concerned mainly the frequency and symmetry of the jets as well as the pattern, duration and velocity of their waves. The 4 above-mentioned patients, with dilated upper urinary tracts and waveforms differentiated from the contralateral ones, were characterized as obstructive. On the other hand, the remaining 4 patients with subclinical ureterocele showed insignificant differences in urine jets and waveforms, and were found to be non-obstructive. CONCLUSION: Conventional sonography of the urinary tract in combination with color Doppler duplex sonography of the ureteral jets can be used in an attempt to diagnose and evaluate a unilateral orthotopic (single system) ureterocele and assess the necessity of intervention to identify the obstruction.