Shahzad Muhammad Asim, Baxi Pravir V, Rodby Roger A
Division of Nephrology, Rush University Medical Center, Chicago, IL, USA.
Can J Kidney Health Dis. 2022 Mar 26;9:20543581221086683. doi: 10.1177/20543581221086683. eCollection 2022.
Nondilated obstructive uropathy (NDOU) is a rare cause of acute renal failure reported in less than 5% of cases of obstructive uropathy. It is typically associated with intrapelvic malignancies and diseases causing retroperitoneal lymphadenopathy and retroperitoneal fibrosis. As these conditions may prevent radiographic dilation of the collecting system, the diagnosis of NDOU may be missed by usual diagnostic testing.
We present a case of acute anuric renal failure in a middle-aged woman with metastatic breast cancer associated with abdominal and retroperitoneal lymphadenopathy. Acute kidney injury was initially deemed secondary to drug-induced acute tubular necrosis (ATN) from bisphosphonate; however, there remained a high clinical suspicion of NDOU due to the presence of enlarged retroperitoneal lymph nodes on CT abdomen and pelvis with concerns for encasement of bilateral renal pelvic regions and ureters.
The patient underwent a retrograde pyelogram which demonstrated questionable narrowing bilaterally at the level of the renal pelvices. This led to an even stronger clinical suspicion of NDOU and urology service was consulted for evaluation.
Bilateral ureteral stents were placed by urology which led to robust urine output and rapid reversal of renal failure over the next 24 to 48 hours.
Despite 2 weeks of anuria and hemodialysis, this patient's creatinine came back to her baseline. She was able to discontinue hemodialysis and her creatinine stabilized at 88.4 μmol/L (1 mg/dL).
Nondilated obstructive uropathy is rare but important diagnosis that requires a high clinical suspicion in the appropriate clinical scenario. The lack of dilatation is believed to be related to encasement of the collecting system by tumor, fibrosis, or as in our case metastatic retroperitoneal lymphadenopathy. As this diagnosis cannot be overlooked, aggressive direct visualization or even intervention with internal or external stenting may be required to both diagnose and treat this condition.
非扩张性梗阻性肾病（NDOU）是急性肾衰竭的一种罕见病因，在梗阻性肾病病例中报告的比例不到5%。它通常与肾盂内恶性肿瘤以及导致腹膜后淋巴结肿大和腹膜后纤维化的疾病相关。由于这些情况可能会阻止集合系统的影像学扩张，常规诊断测试可能会漏诊NDOU。
我们报告一例中年转移性乳腺癌女性患者出现急性无尿性肾衰竭，伴有腹部和腹膜后淋巴结肿大。急性肾损伤最初被认为是双膦酸盐药物引起的急性肾小管坏死（ATN）所致；然而，由于腹部和盆腔CT显示腹膜后淋巴结肿大，怀疑双侧肾盂区域和输尿管受包绕，临床上高度怀疑NDOU。
患者接受了逆行肾盂造影，结果显示双侧肾盂水平可疑狭窄。这进一步增强了临床上对NDOU的怀疑，并咨询了泌尿外科进行评估。
泌尿外科放置了双侧输尿管支架，随后在接下来的24至48小时内尿量显著增加，肾衰竭迅速逆转。
尽管患者无尿并接受了两周的血液透析，但其肌酐水平恢复到了基线。她能够停止血液透析，肌酐稳定在88.4 μmol/L（1 mg/dL）。
非扩张性梗阻性肾病虽罕见，但却是重要的诊断，在适当的临床情况下需要高度的临床怀疑。缺乏扩张被认为与肿瘤、纤维化对集合系统的包绕有关，在我们的病例中是转移性腹膜后淋巴结肿大。由于不能忽视这一诊断，可能需要积极的直接可视化检查，甚至进行内支架或外支架干预来诊断和治疗这种疾病。
