Objective evaluation of the outcome of endopyelotomy using Whitaker's test and diuretic renography.
OBJECTIVE
To assess the role of Whitaker's test (WT) and 99mTc-diethylene triamine penta-acetic acid diuretic renography (DRG) in determining objectively the outcome of endopyelotomy, and to rationalize the frequency and timing of such evaluation after endopyelotomy.


METHODS
Thirty-one patients (age > 15 years) were prospectively evaluated after percutaneous endopyelotomy. WT was performed at 4-6 weeks via the nephrostomy maintained for external drainage, 24 h after removing the splint. DRG was performed at 3, 6 and 12 months, and then annually.


RESULTS
WT performed 24 h after removing the splint diagnosed pelvic pressures in the unobstructed range (< 15 cmH2O) in 21 of the 24 patients were also evaluated with DRG at 3 months. An intra-pelvic pressure of > 15 cmH2O was correlated with a pattern of obstruction on DRG in all three units. Despite an unobstructed WT in 18 patients, categorization of DRG drainage showed disparity in six cases. All six renal units had a large pelvic area (> 15.0 cm2 in two and > 20.0 cm2 in four) and/or a poor renal function (separate glomerular filtration rate [GFR] of < or = 25 ml/min in four of the six units). The drainage pattern on DRG was unevaluable in two renal units as the function was poor (separate GFR < 15 ml/min). During the first year, the drainage pattern on DRG improved in four cases. When followed beyond one year, the drainage pattern deteriorated at 2 years in only one of 14 evaluated renal units with an initial unobstructed WT.


CONCLUSIONS
Using objective methods of evaluation, endopyelotomy was successful in relieving obstruction in 87% of cases. If inaccuracies in the interpretation of DRG, i.e. a large pelvic capacity and poor renal function, are accounted for, the results of WT as early as 24 h after removal of the splint correlated with DRG. Drainage patterns on DRG did not deteriorate during the first year. An early post-operative evaluation with WT or DRG, as appropriate, is thus sufficient evidence of the success of the procedure. Evaluations repeated during the first year after endopyelotomy may be unnecessary.
Department of Urology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
R
R
Ahlawat
N
N
Basarge
D000293:Adolescent; D000328:Adult; D000368:Aged; D004322:Drainage; D005260:Female; D006801:Humans; D006869:Hydronephrosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D007682:Kidney Pelvis / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care; D011312:Pressure; D011446:Prospective Studies; D011866:Radioisotope Renography; D013668:Technetium Tc 99m Aggregated Albumin; D016284:Technetium Tc 99m Pentetate; D016896:Treatment Outcome; D014517:Ureteral Obstruction / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D014546:Urinary Catheterization; D014563:Urodynamics
D013668:Technetium Tc 99m Aggregated Albumin; C057162:technetium Tc 99m DTPA HSA; D016284:Technetium Tc 99m Pentetate