Su-Ju Tsai

Bladder shape impact on the accuracy of ultrasonic estimation of bladder volume

OBJECTIVE Variations in bladder shape can lead to errors in ultrasonic estimation of the bladder volume. The purposes of this study were to compare the accuracies of various formulas to estimate bladder volume from sonographic measurements and to assess the impact of bladder shape on the accuracy of bladder volume estimation. STUDY DESIGN Twenty-four healthy volunteers (13 men, 11 women) and 55 spinal cord injury patients (48 men, 7 women) underwent ultrasonographic measurements of dimensions before and after voiding. Bladder shape was classified as cuboid, ellipsoid, or triangular prism. Ten formulas from the literature were applied to estimate bladder volume, using the volume voided or catheterized as the standard, and then linear regression was used to obtain optimal correction coefficients for the whole data set as well as each of the three bladder shapes. SETTING Rehabilitation hospital affiliated with a medical college. RESULTS The most accurate of the 10 formulas tested was height (H) X transverse depth (Dt) x weight (W) x 0.7 (mean error 17.4%+/-11.6%). Linear regression analysis yield optimal correction coefficients of .72 for the whole data set and .89, .81, and .66 for cuboidal, ellipsoid, and triangular prism-shaped bladders, respectively. The mean error for the estimation of bladder volume using .72 as the correction coefficient was 16.9%+/-11.9% and decreased to 12.7%+/-10.1% (p < .0001, paired t test) when the bladder shape was taken into account. CONCLUSION Using bladder shape for reference and applying the corresponding correction coefficient to volume calculations will improve the accuracy of the estimation.

Effect of single botulinum toxin A injection to the external urethral sphincter for treating detrusor external sphincter dyssynergia in spinal cord injury.

OBJECTIVE To evaluate the effect of a single cystoscopic injection of botulinum toxin to the external urethral sphincter in treating detrusor external sphincter dyssynergia. DESIGN An open treatment trial with pre- and post-treatment evaluations. SUBJECTS A total of 20 suprasacral spinal cord injured patients with pure detrusor external sphincter dyssynergia. METHODS A single dose of 100 IU botulinum toxin A was applied into the external urethral sphincter via cystoscopy. Outcome measurements included maximal detrusor pressure, maximal urethral pressure, detrusor leak point pressure, integrated electromyography, and maximal pressure on static urethral pressure profilometry obtained 4 weeks post-treatment. Post-voiding residuals were checked pre- and post-injection. RESULTS There were significant reductions in integrated electro notmyography and static and maximal urethral pressure, but not in maximal detrusor pressure and detrusor leak point pressure after treatment. Post-voiding residuals were significantly decreased at all evaluation periods. In the sub-group analysis, patients who showed good effects of treatment had significantly lower baseline integrated electro-myography (p<0.05). CONCLUSION This study demonstrates the effect of a single cystoscopic injection of botulinum toxin in detrusor external sphincter dyssynergia. Integrated electromyography is a good evaluation tool for the net effect and dosage of botulinum toxin. Patients with severe spasticity over the external urethral sphincter may require repeated injections or higher doses.

Transperineal Injection of Botulinum Toxin A for Treatment of Detrusor Sphincter Dyssynergia: Localization With Combined Fluoroscopic and Electromyographic Guidance

OBJECTIVE To determine the effectiveness of a combined method for localizing external urethral sphincter for transperineal injection of botulinum toxin A (BTX-A) in the treatment of detrusor sphincter dyssynergia (DSD) in patients with spinal cord injury (SCI). DESIGN A prospective, open-label trial. SETTING A rehabilitation hospital affiliated with a medical university. PARTICIPANTS Eighteen SCI patients with voiding dysfunction resulting from urodynamically confirmed DSD. INTERVENTIONS 100 units of BTX-A injected transperineally into the external urethral sphincter, which was localized using combined fluoroscopic and electromyographic guidance, using a Foley catheter inserted for visualization of vesicourethral anatomy. MAIN OUTCOME MEASURES (1) postvoid residual volume, (2) leak point pressure, (3) maximal intravesical pressure, (4) maximal urethral pressure, (5) quality of life measures for urination, quantified by the Quality of Life Index (QLI). RESULTS Positive clinical outcomes were observed in all 18 patients in this study. The mean reductions in postvoid residual volume, leak point pressure, maximal intravesical pressure, and maximal urethral pressure before and after BTX-A injection were 183ml, 37cm H2O, 45cm H2O, and 92cm H2O, respectively (all P values <.05). The mean QLI significantly improved from -0.68+/-0.27 to 0.66+/-0.19 (P<.01). No significant side effects were noted after injection. The clinical therapeutic effects have shown reductions in occurrence and degree of autonomic dysreflexia, vesicoureteral reflux, hydronephrosis, and urinary tract infection. The bladder management programs also obtained improvements in our patients, either doing intermittent catheterizations less frequently, or resuming spontaneous voiding without indwelling catheters. CONCLUSION With this combined method for localization of the external urethral sphincter, transperineal injection of BTX-A was safe, accurate, easy to perform, and effective for treatment of DSD in patients with SCI.

The accuracy of ultrasonic estimation of bladder volume: A comparison of portable and Stationary equipment

OBJECTIVE To compare the accuracy of portable and stationary ultrasonography equipment in estimating residual bladder volume. DESIGN A prospective study. SETTING A rehabilitation hospital affiliated with a medical university in Taiwan. PARTICIPANTS Sixty-four patients with voiding dysfunction. INTERVENTIONS Each patient received both types of ultrasonography, plus catheterization (as the criterion standard for measuring bladder volume). MAIN OUTCOME MEASURES The mean errors and mean percentage error resulting from use of the 2 types of equipment were recorded. RESULTS Stationary real-time ultrasonography had a lower absolute error (21.9+/-25.0 mL vs 34.4+/-38.2 mL) and percentage error (13.1%+/-10.5% vs 36%+/-52.4%) than the portable ultrasonography (P<.05). CONCLUSION Stationary ultrasonography provided a more accurate estimate of residual bladder volumes than did the portable device. However, portable ultrasonography is more convenient to use and has an acceptable accuracy for clinical use.

Comparison of ultrasonographic renal excursion to fluoroscopic diaphragmatic excursion for the assessment of diaphragmatic function in patients with high cervical cord injury.

OBJECTIVE To compare the renal excursion detected by ultrasonography with the diaphragmatic excursion recorded by fluoroscopy in estimating the diaphragmatic function in patients with high cervical cord injury. DESIGN Prospective, blinded comparative study. SETTING A rehabilitation hospital affiliated with a medical university. PARTICIPANTS Fifteen consecutively admitted patients with high cervical cord injury. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Chest radiographs, fluoroscopy of diaphragmatic motion, and ultrasonography of renal motion. RESULT Of the 15 patients, 2 were diagnosed with hemidiaphragm paralysis using fluoroscopy and renal ultrasonography. The average diaphragmatic excursion was 59 mm (range, 30-83 mm) in 28 nonparalyzed hemidiaphragms. The average renal excursion was 49 mm (range, 28-61 mm). The correlation coefficient for fluoroscopic hemidiaphragm excursion and ultrasonographic renal excursion was .853. CONCLUSION Ultrasonographic renal excursion and fluoroscopic diaphragmatic excursion correlated highly. With the fluoroscopy results as the criterion standard, the diagnostic sensitivity and specificity were both 100% for renal sonography. With the advantages of convenience of use, no radiation exposure, and high reproducibility, renal ultrasonography is recommended as a first-line screening and long-term follow-up tool for assessment of diaphragmatic function.

Sonographic diagnosis of hydronephrosis in patients with spinal cord injury: influence of bladder fullness

OBJECTIVE To investigate and compare the diagnostic accuracy of prevoid and postvoid renal sonography in detecting hydronephrosis in patients with spinal cord injury. STUDY DESIGN A prospective, blind comparison of renal sonography and excretory urography in 67 spinal cord injury patients who underwent periodic urologic examinations. Renal sonography was performed twice, once when the patients bladder was physiologically full (prevoid) and again when it was just emptied (postvoid). RESULTS Of 140 kidneys, 24 from 16 patients were found to have hydronephrosis by excretory urography; 116 kidneys had normal urogram findings. Prevoid sonography missed the diagnosis of hydronephrosis in one kidney and showed hydronephrosis in 18 kidneys that had normal results on excretory urography (sensitivity, 95.8%; specificity, 84.5%; negative predictive value, 99.0%). The postvoid sonograms did not detect hydronephrosis in four kidneys and showed hydronephrosis in six kidneys that had normal results on excretory urography (sensitivity, 83.3%; specificity, 94.8%; negative predictive value, 96.5%). Compared to excretory urography, renal sonography detected eight more upper urinary tract abnormalities, which were confirmed by cystograms or radioisotopic renograms. CONCLUSION Performing renal sonography while the bladder is full can increase the sensitivity in detecting hydronephrosis in asymptomatic spinal cord injured patients.

Value of Doppler ultrasonography in predicting deteriorating renal function after spinal cord injury

PurposeThe authors sought to study the relationship between Doppler ultrasonography and deterioration of renal function in patients with spinal cord injury.Materials and methodsNineteen patients who underwent follow-up with radioisotopic renography were evaluated. Median patient age was 50 [interquartile ratio (IQR) 35–57] years, and time since injury was 4.7 (IQR 1.3–9.2) years. Following Doppler ultrasound, patients were divided into groups based on baseline renal resistive index (RRI): normal RRI (≤0.7), group 1 (n=14); and abnormal RRI (> 0.7), group 2 (n=5), and were followed up with radioisotopic renography 1 or more years later. Annual change in effective renal plasma flow (ERPF) was analysed.ResultsThe 38 kidneys (two for each patient) were stratified by initial RRI, with 28 in group 1 and ten in group 2. Result of univariate generalised estimation equation (GEE) analysis for the factors affecting the change in effective renal plasma flow (ERPF) indicated that the high RRI value (RRI > 0.7) correlated with the change in ERPF. ERPF value in group 2 was significantly decreased (p=0.01) by an average of 60.33 ml/min (standard error = 23.26).ConclusionsAn RRI > 0.7 is a risk factor for future renal function deterioration in patients with spinal cord injury. Thus, annual Doppler ultrasonography to assess the RRI and the degree of hydronephrosis is recommended.RiassuntoObiettivoScopo dello studio è indagare la relazione tra i rilievi Doppler ultrasonografici ed il deterioramento della funzione renale in pazienti con lesione del midollo spinale.Materiali e metodiSono stati valutati 19 pazienti con età media pari a 50 anni [scarto interquartilico (IQR) 35–57] con tempo medio trascorso dal trauma di 4,7 anni (IQR 1,3–9,2), seguiti in follow-up mediante renografia radioisotopica. Tramite valutazione Doppler ultrasonografica, i pazienti sono stati divisi in gruppi basandosi sull’indice di resistività renale (IRR); gruppo 1 (n=13) con IRR normale (≤0,7) e gruppo 2 (n=6) con IRR anormale (>0,7); i Pazienti sono stati in seguito rivalutati almeno un anno dopo, mediante renografia radioisotopica.RisultatiTrentotto reni sono stati assegnati sulla base dell’IRR iniziale in numero di 28 al gruppo 1 e di 10 al gruppo 2. L’analisi univariata mediante equazione di stima generalizzata (GEE) per i fattori che influenzano il flusso renale plasmatico effettivo (FPRE), ha indicato che un elevato IRR (>0,7) correla con il cambiamento del FPRE. Il valore del FPRE nel gruppo 2 è significativamente diminuito (p=0,01), in media 60,33 ml/min (errore standard=23,26).ConclusioniUn IRR >0,7 rappresenta un fattore di rischio per il deterioramento della funzionalità renale in Pazienti con lesioni del midollo spinale. Pertanto si raccomanda l’ecografia Doppler annuale per la stima dell’IRR e dell’entità d’idronefrosi.

Urodynamic Responses to Anal Stretch in Patients With Detrusor Sphincter Dyssynergia

OBJECTIVE To evaluate the urodynamic responses to anal stretch in patients with detrusor sphincter dyssynergia (DSD). DESIGN Descriptive study. SETTING Rehabilitation hospital affiliated with a medical university. PARTICIPANTS Patients (N=36) with suprasacral spinal cord injury who had DSD confirmed on cystometrography. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Detrusor pressure, urethral pressure, and summated electromyogram of external urethral sphincter on cystometrography. RESULTS The urodynamic responses to anal stretch were evaluated in the first half (time 1, 1-15s) and the second half (time 2, 16-30s) of the evaluation time period. The activity of external urethral sphincter was reduced significantly in both times 1 and 2 (P<0.5). The medians of reduction percentages were 33% and 35% for times 1 and 2, respectively. The change of detrusor pressure was not significant in either time 1 or time 2. CONCLUSIONS Anal stretch can reduce the activity of external urethral sphincter without significant change in detrusor pressure.