梗阻性肾病 (ON) 是肾后性急性肾损伤 (AKI) 的常见且可逆的原因，可能由多种病症引起。当双侧上尿路梗阻或单肾患者的一侧尿路梗阻时，就会发生这种情况。只要影像学检查有肾积水的证据，就需怀疑肾盂肾炎。然而，并非所有梗阻患者都会出现肾积水，即使没有肾积水，也可能出现严重梗阻。这种综合征称为非扩张性梗阻性尿路病（NDOU）。它约占尿路梗阻病例的 5%，且诊断具有挑战性。本文对文献进行了概述，旨在确定 NDOU 的主要原因及其临床表现，以便澄清何时在 AKI 病例中怀疑它。由于现有证据的总体质量较低，因此进行了叙述性审查。仅纳入肾后 AKI 且肾内集合系统非扩张或轻度扩张的患者。正如我们的审查所证明的，NDOU 在 50 岁和 60 岁的人中最为普遍，主要影响男性。入院时血清肌酐水平通常非常高。最常见的临床表现包括少尿/无尿、腹痛、水肿或胸腔积液等潴留体征，以及恶心/呕吐。大约四分之三的 NDOU 病例是由于腹膜后纤维化或恶性疾病引起的输尿管外源性压迫所致。通过输尿管支架置入术或经皮肾造口术可以实现有效且微创的尿流改道。 NDOU 的正确诊断可能具有挑战性，但至关重要，因为它可以导致及时治疗，并有可能完全解决梗阻和急性肾衰竭。© 作者 2024。由牛津大学出版社代表出版时代的。

Obstructive nephropathy (ON) is a common and reversible cause of post-renal acute kidney injury (AKI) and may be caused by a variety of conditions. It occurs when both the upper urinary tracts are obstructed, or when one tract is obstructed in patients with a solitary kidney. ON is suspected whenever there is evidence of hydronephrosis at imaging. However, not all patients with obstruction develop hydronephrosis and significant obstruction can be present in the absence of hydronephrosis. This syndrome is called non-dilated obstructive uropathy (NDOU). It accounts for about 5% of cases of urinary obstruction and the diagnosis can be challenging. The current paper provides an overview of the literature aiming to identify the main causes of NDOU and its clinical presentation, in order to clarify when to suspect it among AKI cases. A narrative review was performed due to the overall low quality of the available evidence. Only patients with post-renal AKI and a non-dilated or minimal dilation of the intrarenal collecting system were included. As evidenced by our review, NDOU is most prevalent in the fifth and sixth decades of life and affects mainly the male gender. On hospital admission serum creatinine levels are usually very high. Among the most common clinical presentations are oliguria/anuria, abdominal pain, signs of retention such as oedema or pleural effusion, and nausea/vomiting. About three out of four cases of NDOU are due to an ab-extrinsic compression of the ureters caused by retroperitoneal fibrosis or malignant disease. An effective and minimally invasive urinary diversion is obtained with ureteric stenting or a percutaneous nephrostomy. A correct diagnosis of NDOU may be challenging but it is of paramount importance as it can lead to a prompt management with a potential complete resolution of both obstruction and acute renal failure.© The Author(s) 2024. Published by Oxford University Press on behalf of the ERA.