Percutaneous Pyeloureteral Urodynamics

Nocturnal Excretion in Healthy Older Women and Rationale for a Safer Approach to Sleep Disruption

OBJECTIVES

Insomnia, especially difficulty maintaining sleep, is prevalent among older adults and increases the incidence of falls and fractures. Moreover, the drugs used to treat it exacerbate the risk. Yet current therapies fail to address one of its most common causes in older adults: nocturia and its primary contributor, nocturnal polyuria (NP), especially among the majority of individuals without lower urinary tract symptoms (LUTS). Therefore, we examined the factors associated with nocturia in two groups of such older women and the impact of nocturia on sleep.

DESIGN

Secondary analysis of two observational studies of bladder function in carefully evaluated healthy older women.

SETTING

Academic medical center.

PARTICIPANTS

A total of 39 women without LUTS who had adequate fluid intake (ie, >1200 mL urine output/24 h recorded on their diary), normal videourodynamic testing, and normal daytime frequency (≤7 voids).

MEASUREMENTS

Voided volumes and sleep duration obtained from subjects' 3-day voiding diary, and sleep quality from the Center for Epidemiologic Studies Depression Scale. Nighttime excretion of more than 33% of 24-hour urine volume was considered NP.

RESULTS

Overall, 21 of these healthy subjects (54%) awakened at least once nightly to void, and 19 (90%) of them had NP. Compared with those without nocturia, participants with nocturia had shorter duration of the first uninterrupted sleep period (182 ± 100 vs 250 ± 60 min; P = .03), and they reported worse sleep quality. Two factors contributed independently to nocturia: (1) a larger proportion of 24-hour urine output at night (43.4 ± 7.4% vs 25.4 ± 5.5%; P = <.001) and (2) smaller bladder capacity (484 ± 157 mL vs 608 ± 167 mL; P = .02).

CONCLUSIONS

Nocturia, NP, and reduced bladder capacity are very common even in healthy older women without LUTS and are associated with impaired sleep. Thus applying currently available modalities to address both NP and reduced bladder capacity may effectively treat sleep disruption without incurring the complications of sedative-hypnotics. J Am Geriatr Soc 67:2610-2614, 2019.

Pressure matters: intrarenal pressures during normal and pathological conditions, and impact of increased values to renal physiology

PURPOSE

To perform a review on the latest evidence related to normal and pathological intrarenal pressures (IRPs), complications of incremented values, and IRP ranges during endourology.

METHODS

A literature search was performed using PubMed, restricted to original English-written articles, including animal, artificial model, and human studies. Different keywords were: percutaneous nephrolithotomy, PCNL, ureteroscopy, URS, RIRS, irrigation flow, irrigation pressure, intrarenal pressure, intrapelvic pressure and renal pelvic pressure.

RESULTS

Normal IRPs range from zero to a few cm H₂O. Pyelovenous backflow may occur at pressure range of 13.6-27.2 cm H₂O. During upper tract endourology, complications such as pyelorenal backflow, sepsis, and renal damage are directly related to increased IRPs. Duration of increased IRPs and concomitant obstruction are independent predictors of complication development.

CONCLUSIONS

IRP increase remains a neglected predictor of upper tract endourology complications and its intraoperative monitoring should be taken into consideration. Further research is necessary, to quantify pressures generated during upper tract endourology, and introduce means of controlling them.

The Whitaker test: 35 years on

OBJECTIVE

To describe a 25-year experience of using the Whitaker test in a single tertiary centre for assessing upper urinary tract dilatation, and to evaluate the role of perfusion pressure-flow studies in contemporary urological surgery for equivocal upper tract obstruction.

PATIENTS AND METHODS

In all, 143 patients with suspected upper urinary tract obstruction were investigated by at least one Whitaker test. The original method was extended to include observations on high flow-rate perfusion, abnormal renal pelvic peristalsis and loin pain with no pressure increase. Data on clinical presentation, perfusion pressure-flow studies, diuresis renography and choice of initial therapy were collected prospectively, and the long-term clinical outcome was analysed retrospectively.

RESULTS

In total, 145 studies were assessed; the Whitaker test showed obstructive features at conventional or higher flow rates in 61 cases and unobstructive patterns in 53. There were four equivocal results. Seventeen studies showed abnormal peristalsis within the renal pelvis and in 10 there was 'sensory' loin pain during the test. In patients with idiopathic hydronephrosis, there was agreement between the results of the pressure-flow studies and diuresis renography in 72%. The Whitaker test determined or contributed to the clinical management in 84% of the cases studied. It was accurate in its prediction of outcome in 77% of cases where obstruction was diagnosed and in 77% of unobstructive cases.

CONCLUSIONS

The Whitaker test continues to have a role in modern urological surgery. It should be reserved for assessing potential upper urinary tract obstruction in the following circumstances: equivocal results from less invasive tests; suspected obstruction with poor kidney function; loin pain with a negative diuresis renogram; suspected intermittent obstruction; and gross dilatation with a positive diuresis renogram.

Percutaneous nephrostomy as adjunct management in advanced upper urinary tract infection

OBJECTIVES

To determine by retrospective review of 315 percutaneous nephrostomies, performed for pyonephrosis, whether this intervention has major clinical advantages.

METHODS

From 1977 to 1996, under the direct supervision of the senior author of this report (E.K.L.), at seven hospital sites, 315 patients (181 males, 134 females; 17 to 88 years of age) were treated with percutaneous nephrostomy and antibiotic therapy for infected hydronephrosis.

RESULTS

Additional or disparate pathogens were identified in 116 (36.8%) of 315 patients, leading to a clinically significant change in, or addition of, antibiotics and/or antifungal agents in 84 (73%) of 116. Most notably, we often found a clinically important disparity between the results of cultures obtained from the nephrostomy and those obtained from bladder-urine specimens.

CONCLUSIONS

This retrospective review confirms previously reported advantages of percutaneous upper urinary tract drainage as a potentially life-saving adjunct in the treatment of pyonephrosis. Several case studies highlight the advantage of this maneuver in difficult cases involving obstruction due to extensive fungus or debris. In particular, our review focuses attention on the clinically important insight that urine cultures from percutaneous nephrostomy drainage often identify pathogens that differ from those detected in concurrent bladder cultures.

Update on interventional uroradiology

From its humble beginnings as a method of expediently decompressing the obstructed kidney, the field of interventional uroradiology has evolved in the hands of urologists and interventional radiologists to a means of addressing myriad problems in the urinary tract and has changed the day-to-day practice of urology. The foundation of interventional uroradiology is the creation of an appropriate entry into the urinary system. After a review of this basic procedure, extensions of the technique and new applications of emerging technology are reviewed.

Effect of internal ureteral stenting of normal ureter on the upper urinary tract: an experimental study

The effects of internal stenting of a normal ureter on the upper urinary tract were studied in 34 male rabbits by plain films, intravenous urograms, and 99mTc-DTPA renography at weekly intervals. Moreover, pressure-flow studies of the upper urinary tract were performed, and urine specimens for culture were obtained preoperatively and at the time of sacrifice. Histopathologic examination of the kidney, ureter, and ureterovesical junction was performed after animal sacrifice. Hydroureteronephrosis and stasis with equivocal obstruction were noted after 1 week of stenting. These changes were reversible after stent removal. Prolonged stenting (> 3 weeks) produced moderate to severe hydroureteronephrosis, and renal function was lost in 2 of 18 renal units because of severe hydronephrosis or infection. Ureteral stenting did not produce obstruction at a flow rate as high as 8 ml/minute. Histopathologic examination showed dilation of the pelvicaliceal system and renal tubules, infiltration of the kidney and the ureter with inflammatory cells, mucosal ulceration, and muscular hypertrophy of the ureters. The bladder mucosa showed a severe inflammatory reaction, Brunn nests, and ulceration with occasional metaplasia. Stenting of normal ureters in rabbits produced no harmful effects on the kidney if the stents were removed within 1 week, but prolonged stenting could affect renal and ureteral integrity.

The dilated urinary tract in children. Prospective analysis with correlation of radiological, isotope, pressure perfusion and surgical findings

Moderate and even severe dilatation of the urinary tract in the absence of vesicoureteric reflux may remain stable or show spontaneous resolution. Two such cases are described. Twenty-five children with dilated urinary systems were studied to correlate the radiological, isotope, pressure perfusion and surgical findings. A positive Whitaker test correlated well with the surgical findings and post-operative improvement in renal function in all patients with pelviureteric junction (PUJ) and vesicoureteric junction (VUJ) obstruction. High flow rates of 8.6 and 12 ml are required even in neonates and infants in order to demonstrate obstruction by Whitaker testing.

Measurement of renal pelvis pressures during endourologic procedures

Twenty-five kidneys underwent nephrostomy puncture with placement of a pigtail catheter into an upper pole calyx for manometric recording during nephroscopy without a working sheath and with an Amplatz sheath with and without a Rutner adapter. Intrarenal pressures remained below 16 cm of water (H2O) at all times with the Amplatz sheath with or without a Rutner adapter, whereas without a sheath the pressures ranged from 15 to 31 cm H2O (i.e., pressures associated with significant pyelovenous and pyelosinus backflow). Similar results were obtained in monitoring intrarenal pressures during clinical procedures. A working sheath should be utilized for all percutaneous nephroscopic procedures to minimize the incidence of pyelovenous and pyelosinus backflow as well as of perirenal extravasation of the irrigation solution. Even with a wide-lumen ureteral catheter in place, drainage via the ureter is not sufficient to maintain the intrapelvic pressure in the physiologic range.

Upper urinary tract obstruction in children: current controversies in diagnosis

Our approach to the evaluation and treatment of children with upper urinary tract obstruction is shown in Figure 10. The following guiding principles should be remembered: 1. Intravenous urography and renal ultrasonography are usually insufficient to establish the diagnosis of obstruction in an asymptomatic patient. 2. Diuresis-enhanced renography is diagnostic in nonobstructed systems (spontaneous excretion of the radioisotope before the injection of furosemide) or unequivocally obstructed systems (no excretion of the radioisotope after injection of furosemide). 3. If the results of diuresis-enhanced renography are equivocal, a patient should be evaluated by pressure flow studies before surgical correction is undertaken or a diagnosis of no obstruction. 4. Diuresis-enhanced renography is extremely useful in followup and in evaluating surgical results.

Pressure changes in the dilated upper urinary tract on perfusion at varying flow rates

The conventional Whitaker test assesses the pressure response to a constant perfusion rate of 10 ml/min. Twenty-eight kidneys were perfused at increasing flow rates up to 20 ml/min. Nine became obstructed at rates of 12 to 20 ml/min. The feasibility of such a high urine output has been tested and confirmed. The standard Whitaker test may therefore miss some cases with potentially obstructive hydronephrosis, the effects of which may be deleterious to renal function.

Percutaneous nephrostomy in neonates and infants

A total of 8 patients between 2 days and 2 years old underwent 13 percutaneous nephrostomies for treatment of hydronephrosis. No significant complications were encountered.

Surgical Intervention in Dilated Bilharzial Ureters

Surgery has often been performed for presumed obstruction in dilated bilharzial ureters but with unrewarding results. In this report 55 non-refluxing dilated bilharzial ureters were studied. Perfusion pressure flow studies and diuresis renography with washout technique were used to diagnose the presence or absence of obstruction. Surgery was performed only when obstruction was proven by PPFS and diuresis renography; thus patients were spared an operation when the obstruction could not be confirmed. Antegrade ureteropyelographic findings, evaluation of peristalsis and transport of urine were the basis for the selection of operation performed. The various surgical procedures are discussed.

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.