Uncorrected Proof Nephro-Urol Mon. 2023 November; 15(4):e139952. Published online 2023 November 8. https://doi.org/10.5812/numonthly-139952. Case Report Successful Application of PTRA in a Patient with AKI Due to Severe Unilateral Renal Artery Stenosis: A Case Report with 4-Year Follow-up and Review of Literature Hossein Saghafi 1, * , Mohammad Reza Ahmadi 2 , Mohammad Sina Mirjani 2 and Alireza Saghafi 3 1 Department of Internal Medicine, School of Medicine, Qom University of Medical Sciences, Qom, Iran 2 Student Research Committee, Qom University of Medical Sciences, Qom, Iran 3 School of Medicine, Qom University of Medical Sciences, Qom, Iran * Corresponding author: Department of Internal Medicine, School of Medicine, Qom University of Medical Sciences, Qom, Iran. Email: dr.hosseinsaghafi@gmail.com Received 2023 September 09; Revised 2023 September 20; Accepted 2023 October 25. Abstract Introduction: Renal artery stenosis (RAS) is defined by a decrease in the internal diameter of one or both of the renal arteries. This can lead to renal insufficiency. RAS mostly occurs due to atherosclerosis; however, other conditions can cause this complication. Case Presentation: We present a 66-year-old man who was initially presented with abrupt bilateral lower limbs and scrotal edema in Shahid Beheshti Hospital of Qom. The patient had been regularly visiting the nephrology clinic for mild CKD. Due to the increased levels of creatinine (Cr) and urea in serum, he underwent angiography with suspicion of RAS, and 99% stenosis was confirmed in the left renal artery. Immediately after the diagnosis, we subjected the patient to angioplasty. After removing the arterial stenosis, the patient passed 8 liters of urine during one day, and his symptoms, including generalized edema, weight gain, and dyspnea, were improved gradually. The patient was discharged after 8 days of hospitalization with dramatically improved kidney function and relatively good general conditions. Conclusions: This patient had an uncommon presentation for a unilateral RAS and significant narrowing in the healthy renal artery. Angioplasty and stenting yielded a satisfactory result as a definite and effective treatment, and the patient enjoyed a relatively normal life with preserved kidney function during 4 years of follow-up. Keywords: Renal Artery Stenosis, Acute Kidney Injury, Single Kidney, Angioplasty 1. Introduction Renal artery stenosis (RAS) is the decrease in the internal diameter of one or both renal arteries. It is the major cause of hypertension (1). Regarding gender prevalence, RAS due to fibromuscular dysplasia is more common in women (2). In an autopsy study, atherosclerotic RAS was observed in 27% of patients who were over 50 years old. If the patient had a history of high diastolic blood pressure, this number increased to 53% (3). The main causes of RAS are atherosclerosis and fibromuscular dysplasia (FMD), with a mean frequency of 75% and 20%, respectively. Other causes of RAS are vasculitis (especially polyarthritis nodosa), neurofibromatosis type 1, thromboembolic disease, arterial dissection, and infrarenal aortic aneurysm (1). Here, we present a 66-year-old man who was referred to the internal medicine department of Shahid Beheshti Hospital, Qom City, with the chief complaint of abrupt bilateral lower limbs and scrotal edema. After further investigation, we found that the patient had a 99% stenosis in his left renal artery. 2. Case Presentation In March 2019, a 66-year-old man with a history of mild chronic kidney disease (CKD), coronary artery disease (CAD), benign prostatic hyperplasia (BPH), and hypertension (HTN), was referred from the emergency unit to the Internal Medicine Department of Shahid Beheshti Hospital, Qom City, with the chief complaint of abrupt bilateral lower limbs and scrotal edema. It was a 4+ pitting edema, and the patient mentioned that Copyright © 2023, Saghafi et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC BY 4.0) (https://creativecommons.org/licenses/by/4.0/) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.