Simultaneous measurement of cystometry and diuresis renography during full and empty bladder in neurogenic bladder patients: a preliminary report

Ambulatory urodynamic monitoring: state of the art and future directions

Urodynamic studies are a key component of the clinical evaluation of lower urinary tract dysfunction and include filling cystometry, pressure-flow studies, uroflowmetry, urethral function tests and electromyography. However, pitfalls of traditional urodynamics include physical and emotional discomfort, artificial test conditions with catheters and rapid retrograde filling of the bladder, which result in variable diagnostic accuracy. Ambulatory urodynamic monitoring (AUM) uses physiological anterograde filling and, therefore, offers a longer and more physiologically relevant evaluation. However, AUM methods rely on traditional catheters and pressure transducers and do not measure volume continuously, which is required to provide context for pressure changes. Novel telemetric AUM (TAUM) methods that use wireless, catheter-free, battery-powered devices to monitor bladder pressure and volume while patients carry out their daily activities are currently being investigated. TAUM devices under current development are innovating in the areas of remote monitoring, rechargeable energy sources, device deployment and retrieval and materials engineering to provide increased diagnostic accuracy and improved comfort for patients with incontinence or voiding dysfunction. These devices hold promise for improving the diagnosis and management of patients with lower urinary tract disorders.

Bladder and Ureteral Dysfunction Leading to Hydronephrosis and Hydroureteronephrosis in Adults

Chronic non-stone-related hydronephrosis from supravesical or bladder dysfunction in adults is often detected incidentally. This study aims to review the literature regarding supravesical obstruction or bladder dysfunction leading to bilateral hydronephrosis in adults and to develop an algorithm to identify patients at risk of renal failure. Cross-sectional studies, retrospective and prospective cohorts, clinical trials, and systematic reviews from 1980 to 2017 were included. From 8115 articles screened, 39 met the inclusion criteria. Despite the lack of studies addressing this issue, this review brings up a rational evidence-based algorithm to diagnose and manage adults with bilateral hydronephrosis due to supravesical or bladder disease or dysfunction.

Effect of the abnormal bladder when full on upper tract drainage using a combined cystometrogram-(99m)Tc-mercapto-acetyltriglycine renogram: a prospective study

OBJECTIVE

To examine the relevance of bladder volume in patients with chronic hydronephrosis and abnormal bladder function who lose renal function even though the bladder or reservoir pressure is normal (<40 cmH(2)0).

PATIENTS AND METHODS

In all, 20 patients (16 male; age range 17-67 years) were studied prospectively; 12 had a reconstructed bladder. All had progressive loss of renal function with a glomerular filtration rate (GFR) of >15 mL/min. The study was in three parts: a baseline (99m)Tc-mercapto-acetyltriglycine (MAG3) scan was performed with an empty bladder, then a combined full bladder cystometrogram (CMG) with (99m)Tc-MAG3 study was done supine, and finally repeated in the sitting position. The pressure and volume changes together with the (99m)Tc-MAG3 scintigraphic variables with and without a full bladder were compared.

RESULTS

Of the 17 patients with normotensive bladders, 13 (77%) had functional obstruction of the kidneys with a full bladder. In seven this was threshold dependent and occurred at a total mean (range) bladder volume of 348 (135-720) mL for both positions. In the other six patients there was minimal drainage of isotope from the kidneys even with the bladder empty. When the sitting position was compared with supine, gravity was more important for upper tract drainage in the reconstructed bladders. In five patients the detrusor pressure at which drainage began was close to zero.

CONCLUSIONS

In 13 of 17 patients (77%) the kidneys failed to drain with a full bladder despite 'normal' detrusor pressures. It remains to be seen whether bladder emptying designed to keep the urine volume below the obstructing threshold volume will prevent further loss of renal function.

99mTechnetium-mercaptoacetyltriglycine scintigraphy with full bladder in patients with severe bladder dysfunction

PURPOSE

We evaluated 99mtechnetium-mercaptoacetyltriglycine scintigraphy for detecting threshold bladder volume at which upper tract obstruction occurs in patients with bladder dysfunction.

MATERIALS AND METHODS

A total of 24 patients 19 to 74 years old with severe bladder dysfunction who underwent 99mtechnetium-mercaptoacetyltriglycine scintigraphy and videocystometrogram in a 4-year period were selected for retrospective study. 99mTechnetium-mercaptoacetyltriglycine scintigraphy was done with a full bladder with a mean instilled volume of more than 850 ml saline. In patients in whom an obstructed renal outflow pattern was observed saline was drained at a rate of 100 ml every 5 minutes while dynamic imaging was performed. If results were abnormal, the study was repeated with an empty bladder. Differential function, parenchymal transit time index and outflow efficiency were calculated.

RESULTS

Of the 24 patients 15 had an obstructed outflow pattern with a full bladder, which was relieved at a bladder volume of less than 390 ml (median 300, range 250 to 600). Only 2 of these 15 patients had a normal vesical end filling pressure of less than 20 cm H2O. There was no obstruction in 9 patients, of whom 5 had increased vesical end filling pressures. Followup in patients who had normal tracer outflow on a full bladder showed no decrease in renal function, while a small decrease was seen in patients who had obstructed outflow on a full bladder.

CONCLUSION

This novel, full bladder 99mtechnetium-mercaptoacetyltriglycine scintigraphic technique provides the ability to detect bladder volumes at which obstructive outflow patterns develop in patients with severe bladder dysfunction.