Whitaker Test Research Articles

Endopyelotomy in the Elderly

Elderly patients with ureteropelvic junction obstruction present higher risks for operative repair than younger patients and may benefit from a less invasive approach. We review 18 patients older than 65 years who underwent endopyelotomy for a primary (8) or secondary (10) ureteropelvic junction obstruction. Average followup was 32 months (range 3 to 80). Average operating time, including cystoscopy and patient positioning, was 85minutes. Average hospital stay was 6.3 days. No intraoperative complications were encountered. One failure occurred immediately postoperatively and the patient underwent corrective pyeloplasty. One patient has had intermittent pain but a negative Whitaker test with no evidence of obstruction. The success rate is 88%. Endopyelotomy can be considered a safe and satisfactory procedure for initial treatment of significant ureteropelvic junction obstruction in the elderly.

Does the Whitaker test add to antegrade pyelography in the investigation of collecting system dilatation in renal allografts?

Significant pelvicalyceal dilatation in renal allografts is currently investigated by antegrade pyelography. However, the clinical significance of a radiologically demonstrated narrowing of the ureter is unclear. Over a 21-month period 26 of 155 renal allografts with pelvicalyceal dilatation were investigated by antegrade pyelography. In eight allografts no ureteric stenosis could be identified. Two grafts were shown to have ureteric necrosis and required surgical intervention and 16 of the other grafts appeared to have a ureteric stenosis. 15 of the 16 allografts with radiological ureteric stenosis underwent a concurrent pressure flow study to assess the functional relevance of the ureteric narrowing. As shown by a pressure rise of > 7 mmHg at a perfusion rate of 10 ml min-1, 11 of the 15 grafts were functionally obstructed and were treated by a nephrostomy catheter followed by antegrade insertion of a ureteric stent. The four grafts with a negative pressure flow study were subsequently shown on biopsy to have rejection. The diagnosis of allograft rejection was also confirmed by biopsy in seven of the eight allografts without a radiological ureteric stenosis. The last of the eight allografts was found to be cyclosporin toxic. Pelvicalyceal dilatation of renal allografts is appropriately investigated by antegrade pyelography in combination with a pressure flow study which identifies those grafts with mechanical obstruction.

Radionuclide Constant Pressure Perfusion Study on Measurement of Exit Urine Flow: Experimental and Preliminary Clinical Investigations

To calculate exit urine flow from the renal pelvis to the bladder in hydronephrosis, a simple method, radionuclide constant pressure perfusion study, was used. The mathematical model proposed for calculation of the exit flow (F) was simple: F = (initial slope)/Do’/exp(−0.148d), where F is expressed as flow rate (ml. per minute) of infused radioactive solution into the bladder. The value of the initial slope is expressed as a count rate per minute of time-activity curve of the bladder. Do’ is a count rate per ml. of infused radioactive solution, which was measured by a gamma camera in air, and d is depth (cm.) of the bladder from the body surface to the vesical mucosa. The number −0.148 indicates the effective linear attenuation coefficient of 99mtechnetium, which was determined by a phantom study.In the experimental studies calculated flow correlated well with real pump flow. In preliminary clinical studies in 16 patients (20 kidneys) who underwent nephrostomy, measurement of flow rate at steady intrapelvic pressure with no subtraction of intra-abdominal pressure in 12 of 14 nonobstructed cases demonstrated a pressure-dependent pattern in which flow increased linearly in response to the pressure increase. In 2 nonobstructed children radionuclide constant pressure perfusion study failed: 1 due to crying and 1 to unknown causes. In 2 cases of complete or equivocal obstruction by constant perfusion (Whitaker test) only minimal or no flow rate was found at the maximum intrapelvic pressure increase of 24cm. water. The urine flow was observed only in the repeated study in 3 patients. These phenomena were assumed to be due to immature expertise in the new technique.This new technique can provide physiological measurement of the urine flow at variable levels of constant intrapelvic pressure in hydronephrotic patients, although the pressure-flow relationship for identifying partial obstruction from nonobstruction still remains to be clarified in further clinical studies.

Fluoroscopically Guided Incision of Ureteral Strictures in Pigs with the Cautery-Wire Balloon Catheter: A Phase 1 Study

We investigated a catheter that can longitudinally incise ureteral strictures under fluoroscopic guidance without the need for ureteroscopy and its attendant risks. The catheter consists of a low-pressure balloon and an overlying cautery wire; the balloon allows precise localization of the stricture, seen as a waist in the balloon, and the overlying cautery wire can be fluoroscopically oriented at the stricture.One to two centimeter ureteral strictures were created in 6 swine. Two to four weeks later strictures were incised in a retrograde or antegrade fashion with the cautery-wire balloon catheter, and double J stents placed for a duration of three weeks. In 5 of 6 renal units strictures improved anatomically with resolution of hydronephrosis at 3 to 4 months’ follow-up. Urodynamic absence of obstruction was verified by Whitaker testing. In one animal, the tip of the catheter dislodged in the ureter with subsequent loss of the renal unit. The engineering error that lead to this complication has since been rectified. With correction of the aforementioned problem, this Phase 1 study has demonstrated the feasibility, safety and preliminary efficacy of the cautery-wire balloon catheter for endourologic management of ureteral strictures.

Endopyelotomy and endoureterotomy with the acucise ureteral cutting balloon device: preliminary experience.

Endoureterotomy and endopyelotomy usually involve an endoscopic antegrade approach. In an effort to simplify this technique, we designed an 8-mm balloon catheter with a 100-microns electrocautery cutting wire (Acucise) for retrograde incision of the ureter under fluoroscopic control. Twenty-eight patients with ureteral or ureteropelvic junction obstruction of 3.5 cm or less underwent Acucise endoureterotomy or endopyelotomy. The average operating time was 100 minutes, and the average hospital stay was 2.6 days. Follow-up was obtained with a subjective symptom score, intravenous urography, diuretic renal scan, a Whitaker test, or various combinations thereof. All patients had a minimum of 3 months of follow-up (mean 3.8 months; range 3-9 months). Overall, of the 21 patients who had symptoms of upper tract urinary obstruction, 14 (67%) had complete resolution, and another 4 (19%) had partial resolution, of their symptoms. Postoperative studies demonstrated normal upper tracts in 71% and improvement in another 14% of the patients. In our experience, the Acucise ureteral cutting balloon device provides an effective and efficient means for performing a retrograde endoureterotomy or endopyelotomy.

Laminar submerged jets by color Doppler ultrasound. A model of the ureteral jet phenomenon.

The authors developed and tested a technique to noninvasively measure ureterovesical junction (UVJ) pressure gradients. Such a technique could be used to evaluate ureteral reflux and obstruction. Color Doppler ultrasound measurements of an in vitro model of the ureteral jet were performed. The authors show that the orificial rate of momentum transfer of the ureteral jet (from which the intraluminal pressure in the ureter can be calculated) can be determined to within 45% to 94% of its true value depending primarily on the flow sensitivity of the color flow imager. Marked improvement in the momentum calculation (> 80%) is achieved when a low-flow sensitivity is used. Such noninvasive measurements could replace more invasive techniques (eg, the Whitaker test or cystoscopy with or without ureteral cannulation), which seriously perturb the system of interest.

Self-expanding metal stents for palliative treatment of malignant ureteral obstruction.

We studied the immediate and long-term efficacy of the Wallstent device in the treatment of ureteral obstruction caused by malignant disease. In 23 patients (30 ureters), self-expanding metal stents were implanted endoscopically (n = 23), percutaneously (n = 5), or bidirectionally (n = 2) because of extrinsic malignant ureteral obstruction. Patients who met the following criteria were selected for stent implantation: (1) life expectancy of at least 6 months, (2) current polychemotherapy, (3) increasing levels of serum creatinine, and (4) severe clinical signs and symptoms associated with hydronephrosis. Obstruction was diagnosed by using sonography and excretory urography. After radiologic localization and dilatation of the stenosis, the Wallstent device was inserted. For 4 weeks, a double-J catheter inserted through the stent was kept in place in order to prevent obstruction by reversible hyperplastic reaction of the urothelium. Patients were followed up for 31 weeks (range, 3-75 weeks). Follow-up included sonography, excretory urography, and determination of serum levels of creatinine in all cases and furosemide scintigraphy and the Whitaker test in selected cases. Implantation of the Wallstent device was successful in 30 (97%) of 31 cases attempted. The survival rate was 81% after 6 months and 61% after 8 months. The primary patency was 83% after 30 weeks. Complications were macrohematuria (one patient) and incrustation (two patients). No infection and no migration or compression of the stent were observed. Implantation of a Wallstent device is a safe and effective alternative to double-J catheter placement in tumor-associated ureteral obstruction.

“Well-tempered” diuresis renography: Its historical development, physiological and technical pitfalls, and standardized technique protocol

Differentiating the various causes of hydronephrosis from that of obstruction can be very difficult. Diuretic renography has been adopted as a noninvasive clinical management tool to assist in this differentiation. However, the correlation of the results of diuresis renography, the Whitaker test, and the surgical results has only been between 40% and 85%. This is believed to be due to the many physiological factors and technical pitfalls of the technique. These include variable renal function, variable compliance of the collecting system, the effect of back pressure from a full bladder, the state of hydration, the choice of radiopharmaceutical, and the timing of the diuretic injection. Even the technique of measuring the clearance half-time (T 1/2) is controversial, with at least eight different methods defined. In order to diminish the effect of these variables, a standardized protocol for diuretic renography has been proposed by a consortium of members of the Society for Fetal Urology and the Pediatric Nuclear Medicine Club of the Society of Nuclear Medicine. These include a standardized hydration with a dilute glucose solution, bladder catheterization and measurement of urine output response, uniform radiopharmaceutical choice, and diuretic dose with specific timing of the diuretic injection. The various methods for T 1/2 calculation are illustrated, and various stereotypical renogram and diuresis response curves are offered as aids in the interpretation of the study. Diuresis renography is one of the most complex functional studies in nuclear medicine today. A thorough understanding of the physiological basis for diuresis renography and the pitfalls of the technique is required for its appropriate use in the management of patients suspected of urinary tract obstruction.

Symptomatic renal obstruction or urosepsis during pregnancy: treatment by sonographically guided percutaneous nephrostomy.

Seven pregnant women with symptomatic hydronephrosis had sonographically guided percutaneous nephrostomy for pyosepsis (five patients) or for pain with azotemia (two patients with renal transplants). Antibiotics had been ineffective in controlling pyosepsis in each patient; retrograde ureteral catheterization via cystoscopy was unsuccessful in one patient. After percutaneous nephrostomy, prompt clinical improvement was observed in all patients (i.e., sepsis was relieved and pain abated). Labor was not induced in any of the patients, and no adverse effects occurred to any fetus or mother. Eleven (eight percutaneous nephrostomy, three catheter exchanges) of the 12 procedures were done without conventional radiography and with sonographic guidance alone. After percutaneous nephrostomy, maneuvers to obtain a diagnosis and to treat the obstruction (if necessary) were delayed until after delivery. The causes of ureteral obstruction were calculi (four patients) and a gravid uterus (three patients). After delivery, stones were removed either percutaneously (one patient) or cystoscopically (two patients) or passed spontaneously (one patient); resolution of obstruction by the gravid uterus was proved by Whitaker test after delivery. Sonographically guided percutaneous nephrostomy is an effective and safe method to treat pregnant women who have symptomatic obstructive hydronephrosis associated with either pyosepsis or azotemia. The procedure is rapid, requires minimal anesthesia, has no radiation, and is safe for the fetus. The technique is a useful and perhaps preferable alternative to more invasive surgical therapy or retrograde stenting.

Outcome of hydronephrosis diagnosed antenatally

We evaluated 23 neonates with prenatally diagnosed dilatation of the renal pelvis involving 33 renal units. The dilatation was graded from 0 to 4 by ultrasonography. Diuresis renography was used to evaluate differential renal function. The patterns of the excretory curve following administration of furosemide were analyzed. Antegrade pyelography and pressure flow studies were done in selected patients. The mean follow-up was 34 weeks. The single most important prognostic indicator in this group of patients was the degree of dilatation on ultrasonography. Six of 7 renal units with grade I hydronephrosis improved and 1 remained stable on follow-up. Four of the 12 renal units with grade II hydronephrosis improved spontaneously; 1 remained stable. Three of 11 renal units with grade III hydronephrosis either improved or remained stable. The measurement of differential renal functions on DTPA renography did not correlate well with the degree of dilatation when renal size and parenchymal thickness were adequate. The excretory curves after lasix administration were not helpful to determine treatment in the neonatal period. Seventeen renal units (7 grade II, 9 grade III, 1 grade IV) were treated surgically due to persistent dilatation, evidence of obstruction on either DTPA renography or the Whitaker test, or because of impaired renal function. Sixteen of the 33 renal units diagnosed prenatally improved with observation. Of all the parameters studied only the degree of dilatation on ultrasonography correlated well with the prognosis. We conclude that a period of observation between 6 months and 1 year prior to performing a pyeloplasty in kidneys with good renal function is not detrimental to function and will allow one half of the dilated renal units to improve spontaneously.

Partial unilateral ureteric obstruction alters regional renal blood flow

Complete unilateral ureteric obstruction decreases ipsi-lateral and increases contra-lateral renal blood flow, with shunting of intrarenal blood flow from outer to inner cortical zones. We tested the hypothesis that partial unilateral ureteric obstruction would also result in alterations in renal perfusion patterns. In five dogs, the left ureter was partially obstructed for 4 weeks and then reimplanted into the bladder for a further 4 weeks. Whitaker tests confirmed partial ureteric obstruction. Renal blood flow was assessed at each stage by distribution of radioactively labelled microspheres prior to and following ureteric obstruction and after reimplantation. Partial unilateral ureteric obstruction significantly decreased total blood flow to the ipsi-lateral kidney (51% vs 26%;P<0.05) and increases total blood flow to the contralateral kidney (49% vs 74%;P<0.05). In the ipsilateral kidney, partial ureteric obstruction induced a significant decrease in outer cortical blood flow (57% vs 76%;P<0.01) and a concomitant increase in inner cortical blood flow (35% vs 18%;P<0.02). A similar, albeit less marked, shunting of blood from outer to inner cortex was seen in the contralateral kidney. Relief of sbstruction after 4 weeks did not restore the renal circulation to its pre-obstruction profile. We speculate that the alterations in intrarenal blood flow may be hormonally mediated.

Ureteronephroscopic Endopyelotomy

The percutaneous nephrostomy tract has provided urologists with antegrade access to the upper urinary tract. Via this approach ureteropelvic junction obstruction has been treated with an endoscopically controlled incision with a cold knife. While less invasive than an open operation, we have noted significant discomfort from the 24 to 32F percutaneous tract. Accordingly, we sought to achieve the same results by using a less invasive approach, that is retrograde ureteronephroscopic endopyelotomy.A total of 10 patients (9 women and 1 man) with 5 primary and 5 secondary ureteropelvic junction obstructions underwent ureteroscopic endopyelotomy with a 3 or 5F Greenwald cutting electrode passed through a 12F rigid, 10.8F flexible or 9.8F flexible deflectable ureteronephroscope. Preoperatively, ureteropelvic junction obstruction was documented by a furosemide washout renal scan and/or a Whitaker test in 8 of 10 patients. In 2 patients an excretory urogram or retrograde pyelography was diagnostic. Duration of the procedure averaged 180 minutes (245 minutes with a concurrent Whitaker test).At the conclusion of the procedure a 7/14F indwelling ureteral stent was placed. The nephrostomy tube was removed after 3 days and average hospital stay was 5 days. The ureteral stents were routinely left in place for 6 weeks. Followup in 10 patients averaged 12 months. Flank pain was largely resolved in all patients. A followup Whitaker test, excretory urogram or renal scan ultimately has demonstrated decreased or no obstruction in 9 of 10 patients.In summary, early results with retrograde ureteronephroscopic endopyelotomy, specifically in female patients, appear to be promising. Morbidity is minimal and efficacy is satisfactory given the favorable objective response noted in 90% of the patients.

The Importance of Visualizing the Ureter before Performing a Pyeloplasty

Records were reviewed of 100 patients who underwent an operation for ureteropelvic junction obstruction from 1978 to 1989:14 cases were bilateral and 17 were antenatally diagnosed. The ureter was opacified preoperatively in all but 1 patient: in 65 by retrograde pyelography, in 18 by antegrade pyelography, either through a nephrostomy tube with which the patient was referred or during a Whitaker test, in 9 by vesicoureteral reflux seen on voiding cystourethrography performed before an operation for ureteropelvic junction obstruction and in 7 by an excretory urogram. Of the 65 patients who underwent retrograde pyelography 29 had a discrete area of narrowing. However, 36 patients had something more, including a longer segment of narrowing (13), tortuosity of the upper ureter (8), more than 1 area of narrowing (11), high insertion of the ureter on the renal pelvis (3) and compression of the ureter by the lower pole of the kidney (1). In 10 patients referred for reoperation after failed pyeloplasty there was narrowing of the ureter below the level of the prior pyeloplasty.Although indications for retrograde pyelography are fewer today with the various modern imaging modalities in current use, we believe a retrograde examination should be performed before pyeloplasty if the ureter has not been well shown by other means. The retrograde catheter should be small and soft, so as to create no edema or other injury to the lower ureter. The study is done with the patient under the same anesthesia as the pyeloplasty and not at a previous time. All 114 pyeloplasties in these 100 patients were successful.

Diuretic Ultrasound. A Non‐invasive Technique for the Assessment of Upper Tract Obstruction

A study was made of the diagnostic reliability of renal ultrasound with a diuretic in the evaluation of upper tract obstruction. The test comprised an initial renal ultrasound examination followed by the intravenous injection of 250 ml physiological saline with 40 mg frusemide; further ultrasound scans were carried out from 5 to 150 minutes later. A total of 67 patients was studied and the results were compared with those of diuretic intravenous urography, diuretic renography and, in some cases, the Whitaker test. Dynamic ultrasound with a diuretic showed a sensitivity of 94%, specificity of 94%, positive predictive value of 91% (obstructive), negative predictive value of 96% (non-obstruction) and a total diagnostic capacity of 94%.

An experimental technique for renal intrapelvic access

This study describes an experimental technique for insertion of an indwelling cannula into the canine renal pelvis, and demonstrates its use in the measurement of pelviureteric pressure and motility, creatinine clearance, Whitaker tests, nephrostograms and nephrostomy drainage. The system, which consists of cannula, Heplock and plastic fixation disc, has been inserted into 53 canine kidneys (48) dogs, and percutaneous needle passage into the subcutaneously placed Heplock was used to gain access to the renal pelvis. This technique was successful in virtually all cases (131 separate procedures), and there were few complications. The indwelling intrapelvic cannula is a simple, cheap and reliable method of gaining longterm renal intrapelvic access in the dog, and has many experimental applications.

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 10ml./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.

This Month in Investigative Urology: Diuretic Renograms and the Whitaker Test

This Month in Investigative Urology: Diuretic Renograms and the Whitaker Test

Anastomosed ureters: fluoroscopically guided transconduit retrograde catheterization.

Fluoroscopically guided, transconduit retrograde catheterization of ureters that have been diverted to a bowel conduit is often feasible in patients with patient ureteroenteral anastomoses who might otherwise require a percutaneous nephrostomy (PCN) for reasons other than high-grade anastomotic obstruction. This procedure was attempted on 14 occasions and successfully accomplished on 12. In 11 of these cases, retrograde catheterization obviated PCN to provide renal drainage for a partially obstructing ureteral stricture or obstructing renal calculi, to remove ureteral calculi, or to insert a new ureteral stent after an unsuccessful attempt to exchange an existing occluded retrograde ureteral stent. The procedure also obviated Whitaker testing. On one occasion the retrograde procedure greatly facilitated subsequent PCN in an obese patient with faintly opaque calyceal calculi. These procedures were accomplished with standard angiographic equipment and, in many instances, Teflon sheaths in the bowel conduit to stabilize catheters and guide wires. No complications were encountered. The two patients whose ureters could not be catheterized in retrograde fashion subsequently required PCN.

Two-needle modification of the Whitaker test.

British Journal of UrologyVolume 62, Issue 4 p. 388-388 Two-needle Modification of the Whitaker Test P. G. WENTZELL, P. G. WENTZELL Departments of Urology and Radiology. Royal Liverpool Children's Hospital, LiverpoolSearch for more papers by this authorA. J. ARNOLD, A. J. ARNOLD Departments of Urology and Radiology. Royal Liverpool Children's Hospital, LiverpoolSearch for more papers by this authorH. CARTY, H. CARTY Departments of Urology and Radiology. Royal Liverpool Children's Hospital, LiverpoolSearch for more papers by this authorA. M. K. RICKWOOD, Corresponding Author A. M. K. RICKWOOD Departments of Urology and Radiology. Royal Liverpool Children's Hospital, LiverpoolDepartment of Urology, Royal Liverpool Children's Hospital, Alder Hey, Eaton Road, Liverpool L12 2AP.Search for more papers by this author P. G. WENTZELL, P. G. WENTZELL Departments of Urology and Radiology. Royal Liverpool Children's Hospital, LiverpoolSearch for more papers by this authorA. J. ARNOLD, A. J. ARNOLD Departments of Urology and Radiology. Royal Liverpool Children's Hospital, LiverpoolSearch for more papers by this authorH. CARTY, H. CARTY Departments of Urology and Radiology. Royal Liverpool Children's Hospital, LiverpoolSearch for more papers by this authorA. M. K. RICKWOOD, Corresponding Author A. M. K. RICKWOOD Departments of Urology and Radiology. Royal Liverpool Children's Hospital, LiverpoolDepartment of Urology, Royal Liverpool Children's Hospital, Alder Hey, Eaton Road, Liverpool L12 2AP.Search for more papers by this author First published: October 1988 https://doi.org/10.1111/j.1464-410X.1988.tb04378.xCitations: 5AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article.Citing Literature Volume62, Issue4October 1988Pages 388-388 RelatedInformation

Ureterorenoscopic Endopyelotomy: Preliminary Report

In conclusion, the concept of endopyelotomy remains extremely attractive, and the early results appear promising. However, the methodology appears to be far in advance of the actual science. Objective studies with furosemide washout renography or Whitaker tests prior to endopyelotomy and at 1 year following endopyelotomy are lacking. Currently, because of its less-invasive nature, lack of external catheters, and rapid convalescence, we are continuing to use a ureteroscopic approach to endopyelotomy. However, although this method overall represents a less-invasive approach, the reader is cautioned to keep in mind that our patient series is too small and the follow-up is too brief for any conclusions to yet be drawn in favor of this method.