Saraga Marijan, Saraga-Babić Mirna, Arapović Adela, Vukojević Katarina, Pogorelić Zenon, Simičić Majce Ana
School of Medicine, University of Split, 21000 Split, Croatia.
Department of Anatomy, Histology and Embryology, School of Medicine, University of Split, 21000 Split, Croatia.
Biomedicines. 2024 May 5;12(5):1015. doi: 10.3390/biomedicines12051015.
Vesicoureteral reflux (VUR) is defined as the urine backflow from the urinary bladder to the pyelo-caliceal system. In contrast, intrarenal reflux (IRR) is the backflow of urine from the renal calyces into the tubulointerstitial space. VURs, particularly those associated with IRR can result in reflux nephropathy when accompanied by urinary tract infection (UTI). The prevalence of IRR in patients with diagnosed VUR is 1-11% when using voiding cystourethrography (VCUG), while 11.9-61% when applying the contrast-enhanced voiding urosonography (ceVUS). The presence of IRR diagnosed by VCUG often correlates with parenchymal scars, when diagnosed by a 99mTc dimercaptosuccinic acid scan (DMSA scan), mostly in kidneys with high-grade VURs, and when diagnosed by ceVUS, it correlates with the wide spectrum of parenchymal changes on DMSA scan. The study performed by both ceVUS and DMSA scans showed IRRs associated with non-dilated VURs in 21% of all detected VURs. A significant difference regarding the existence of parenchymal damage was disclosed between the IRR-associated and IRR-non-associated VURs. A higher portion of parenchymal changes existed in the IRR-associated VURs, regardless of the VUR grade. That means that kidneys with IRR-associated VURs represent the high-risk group of VURs, which must be considered in the future classification of VURs. When using ceVUS, 62% of places where IRR was found were still unaffected by parenchymal changes. That was the basis for our recommendation of preventive use of long-term antibiotic prophylaxis until the IRR disappearance, regardless of the VUR grade. We propose a new classification of VURs using the ceVUS method, in which each VUR grade is subdivided based on the presence of an IRR.
膀胱输尿管反流（VUR）被定义为尿液从膀胱反流至肾盂 - 肾盏系统。相比之下，肾内反流（IRR）是指尿液从肾盏反流至肾小管间质间隙。VUR，尤其是那些与IRR相关的VUR，当伴有尿路感染（UTI）时可导致反流性肾病。在诊断为VUR的患者中，使用排尿性膀胱尿道造影（VCUG）时IRR的患病率为1% - 11%，而应用对比增强排尿超声检查（ceVUS）时为11.9% - 61%。通过VCUG诊断出的IRR通常与实质瘢痕相关，通过99mTc二巯基丁二酸扫描（DMSA扫描）诊断时，大多在伴有高级别VUR的肾脏中，而通过ceVUS诊断时，它与DMSA扫描上广泛的实质改变相关。ceVUS和DMSA扫描均进行的研究表明，在所有检测到的VUR中，21%的VUR与非扩张性VUR相关的IRR有关。在与IRR相关和与IRR无关的VUR之间，在实质损伤的存在方面存在显著差异。无论VUR分级如何，与IRR相关的VUR中存在更高比例的实质改变。这意味着与IRR相关的VUR的肾脏代表了VUR的高危组，在未来VUR的分类中必须予以考虑。使用ceVUS时，发现IRR的部位中有62%仍未受实质改变影响。这就是我们建议无论VUR分级如何，在IRR消失之前预防性长期使用抗生素预防的依据。我们建议使用ceVUS方法对VUR进行新的分类，其中每个VUR分级根据IRR的存在进行细分。
