Homsy Y L, Tripp B M, Lambert R, Campos A, Capolicchio G, Dinh L, Chheda H
Division of Pediatric Urology, Hôpital Sainte-Justine, Université de Montréal, Quebec, Canada.
J Urol. 1998 Oct;160(4):1446-9. doi: 10.1016/s0022-5347(01)62587-4.
We evaluated the difference in response patterns of captopril versus standard renography for assessing hydronephrosis due to suspected ureteropelvic and ureterovesical junction obstruction. This technique may identify hydronephrotic kidneys in which normal function is maintained by vasoactive compensatory mechanisms. Sustained obstruction may cause these mechanisms to fail, and expose the kidneys to permanent functional deterioration in the long term.
We prospectively studied 15 boys and 8 girls with a mean age of 3.5 years with grades III to IV/IV hydronephrosis. Evaluations included renal sonography, standard diuretic and captopril renography, glomerular filtration rate, voiding cystography, serum creatinine, blood pressure, and urinalysis with culture and sensitivity. Obstruction was suspected at the ureteropelvic junction in 19 kidneys and at the ureterovesical junction in 9. We compared differential function values obtained by standard diuretic and captopril renography.
We observed certain patterns in response to captopril renography, including pattern 1--unilateral decrease in hydronephrotic kidney relative function in 5 of 23 cases, 2--bilateral decreased function in 2, 3--bilateral increased function in 4 and 4--no change in function in 12 on standard renography. When half-time was more than 20 minutes on standard diuretic renography in 8 cases, captopril renography showed an ipsilateral decrease and bilateral increase in glomerular filtration rate in 4 and 1, respectively, and no change in 3. In 12 of the 23 patients (52%) there was no difference in the results of captopril and diuretic renography as well as no change in differential function on standard diuretic renography during 1 1/2 years of observation. Surgical correction was performed in 4 patients in whom half-time was greater than 20 minutes and differential function was decreased on captopril renography.
Our preliminary study reveals that there may be a role for captopril renography for detecting renin-angiotensin system mediated compensatory mechanisms in obstructive uropathy. When such compensatory mechanisms are activated, they may be unmasked by captopril, producing 1 of 4 patterns on renography and glomerular filtration rate. Patterns may indicate different degrees of impending renal function impairment and, thus, they may become useful for determining the progression of injury, when present, and the appropriate timing of surgical intervention.
我们评估了卡托普利肾图与标准肾图在评估疑似输尿管肾盂和输尿管膀胱连接部梗阻所致肾积水时反应模式的差异。该技术可能识别出通过血管活性代偿机制维持正常功能的肾积水肾脏。持续性梗阻可能导致这些机制失效，并使肾脏长期面临永久性功能恶化。
我们前瞻性研究了15名男孩和8名女孩，平均年龄3.5岁，患有III至IV/IV级肾积水。评估包括肾脏超声检查、标准利尿和卡托普利肾图、肾小球滤过率、排尿性膀胱尿道造影、血清肌酐、血压以及尿培养和药敏分析。19个肾脏疑似输尿管肾盂连接部梗阻，9个疑似输尿管膀胱连接部梗阻。我们比较了标准利尿肾图和卡托普利肾图获得的分肾功能值。
我们观察到卡托普利肾图的某些反应模式，包括模式1——23例中有5例肾积水肾脏相对功能单侧下降，模式2——2例双侧功能下降，模式3——4例双侧功能增加，模式4——12例标准肾图功能无变化。当8例患者标准利尿肾图的半衰期超过20分钟时，卡托普利肾图显示4例肾小球滤过率同侧下降，1例双侧增加，3例无变化。23例患者中有12例（52%）在1年半的观察期内，卡托普利肾图和利尿肾图结果无差异，标准利尿肾图分肾功能也无变化。4例半衰期大于20分钟且卡托普利肾图分肾功能下降的患者接受了手术矫正。
我们的初步研究表明，卡托普利肾图在检测梗阻性肾病中肾素-血管紧张素系统介导的代偿机制方面可能有作用。当这种代偿机制被激活时，它们可能被卡托普利揭示出来，在肾图和肾小球滤过率上产生4种模式之一。这些模式可能表明即将发生的肾功能损害程度不同，因此，当存在损伤时，它们可能有助于确定损伤的进展以及手术干预的合适时机。
