Bhandari Sadikshya, Tamdin Tenzin, Raut Raymond
Department of Internal Medicine, Danbury Hospital/Nuvance Health, Danbury, Connecticut, USA.
Department of Nephrology, Danbury Hospital/Nuvance Health, Danbury, Connecticut, USA.
Case Rep Nephrol. 2025 Mar 19;2025:2777348. doi: 10.1155/crin/2777348. eCollection 2025.
Renal hemosiderosis, marked by the buildup of hemosiderin in the renal cortex due to chronic intravascular hemolysis, can lead to acute kidney injury. Iron deposited may exacerbate renal damage through processes like lipid peroxidation and free radical formation, impacting cellular function and precipitating renal disease. Although seen commonly with chronic intravascular hemolysis in the setting of sickle cell anemia, thalassemia, and in the setting of prosthetic cardiac valves. While acute renal failure following prosthetic cardiac valve placement is relatively uncommon, some cases of renal injury in the setting of mechanical hemolysis have been reported, in the postsurgical period, typically within 2 weeks. In this case report, we present a 67-year-old male patient, following mitral valve repair, who developed anemia within 2 weeks of the repair. Evaluation with echocardiography did not initially show findings of worsening mitral regurgitation, however, his anemia and kidney function worsened over the next 6 months. Further evaluation, during that time showed worsening mitral valve regurgitation in repeated echocardiography, with renal hemosiderosis confirmed via kidney biopsy, revealing glomerulosclerosis with hemosiderin deposits. Due to persisting anemia and worsening kidney function, the patient is being planned for a mitral valve replacement. The potential recovery of renal function remains uncertain. Despite the common occurrence of intravascular hemolysis following prosthetic valve placement or valve repair, only a few cases of acute renal failure have been reported. In these cases, severe hemolytic anemia developed shortly after surgery, within 2 weeks, with increased levels of creatinine, even reported as high as 8.2 mg/dL and renal biopsy revealed acute tubular injury and widespread tubular hemosiderosis, resembling the findings in the index case. Diagnosis depends on the evaluation of anemia, showing signs of hemolysis, with echocardiology findings of worsening valvular abnormalities, and kidney biopsy findings showing hemosiderin deposits. Treatment strategies encompass the management of anemia alongside considerations for either mitral valve replacement or repair. This case underscores the importance of considering the possibility of renal hemosiderosis, associated with mitral valve repair. The delay in diagnosis observed in this case is not uncommon, and timely recognition becomes pertinent to prevent irreversible renal injury and improve long-term outcomes.
肾含铁血黄素沉着症，其特征是由于慢性血管内溶血导致含铁血黄素在肾皮质中蓄积，可导致急性肾损伤。沉积的铁可通过脂质过氧化和自由基形成等过程加剧肾损伤，影响细胞功能并引发肾脏疾病。虽然在镰状细胞贫血、地中海贫血以及人工心脏瓣膜情况下的慢性血管内溶血中常见。虽然人工心脏瓣膜置换术后急性肾衰竭相对少见，但在机械性溶血情况下，术后一段时间（通常在2周内）已有一些肾损伤病例报道。在本病例报告中，我们介绍了一名67岁男性患者，在二尖瓣修复术后2周内出现贫血。最初的超声心动图评估未显示二尖瓣反流恶化的迹象，然而，在接下来的6个月里，他的贫血和肾功能恶化。在此期间的进一步评估显示，重复超声心动图检查发现二尖瓣反流恶化，经肾活检证实为肾含铁血黄素沉着症，显示肾小球硬化伴有含铁血黄素沉积。由于贫血持续存在且肾功能恶化，该患者计划进行二尖瓣置换。肾功能的潜在恢复情况仍不确定。尽管人工瓣膜置换或瓣膜修复后血管内溶血很常见，但只有少数急性肾衰竭病例被报道。在这些病例中，术后不久（2周内）就出现了严重的溶血性贫血，肌酐水平升高，甚至高达8.2mg/dL，肾活检显示急性肾小管损伤和广泛的肾小管含铁血黄素沉着症，与本例患者的发现相似。诊断取决于对贫血的评估，显示溶血迹象，超声心动图发现瓣膜异常恶化，以及肾活检发现含铁血黄素沉积。治疗策略包括贫血的管理以及二尖瓣置换或修复的考虑。本病例强调了考虑与二尖瓣修复相关的肾含铁血黄素沉着症可能性的重要性。本病例中观察到的诊断延迟并不罕见，及时识别对于预防不可逆的肾损伤和改善长期预后至关重要。
