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.
Ahlawat
R
R
Department of Urology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
Basarge
N
N
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