高齡患者於雙側逆行性腎盂攝影後發生延長性反射性無尿：一例後腔靜脈輸尿管病例報告暨迷你文獻回顧

黃韋鈞、張寶霞、曾浩翔    

中國附醫泌尿科、中國醫藥大學北港附設醫院內科部腎臟科、中國醫藥大學北港附設醫院外科部泌尿科

Prolonged Reflex Anuria Following Bilateral Retrograde Pyelography in an Elderly Patient with Retrocaval Ureter: A Case Report and Mini Review

Wei-Chun, Huang¹, Pao-Hsia Chang², Hao Xiang Chen^1,3 

¹Department of Urology, China Medical University Hospital, China Medical University,

²Division of Nephrology, Department of Internal Medicine, China Medical University Beigang Hospital

³ Division of Urology, Department of Surgery, China Medical University Beigang Hospital

Purpose:

While retrograde pyelography (RP) is a standard diagnostic and intraoperative tool, it can precipitate rare but severe complications, including reflex anuria (RA). We present the case of an 80-year-old male who experienced significant renal deterioration and prolonged oliguria following bilateral RP, eventually requiring 29 days for renal function to return to baseline. We also provide a literature review comparing our findings with previously reported cases of reflex anuria. Maintaining a high index of suspicion for RA is essential when diagnosing post-RP acute kidney injury, as early recognition of this neurovascular reflex can guide conservative management and prevent unnecessary invasive interventions.

Case report

  An 80-year-old Taiwanese man with a medical history significant for a cerebrovascular accident (CVA) with right-sided weakness in March 2025 and an intracranial hemorrhage (ICH) following a fall in September 2025 (status post-surgical intervention) was admitted to nephrology service due to urinary tract infection. Baseline laboratory data showed chronic kidney disease (Cr: 1.26 mg/dL, eGFR: 57.7 mL/min/1.73 m²). During hospitalization, persistent hematuria was observed despite medical management. Computed tomography urography (CTU) arranged on admission day 15 revealed filling defect over right pelvis, ureteral peristalsis or tumor could not rule out. He had not developed renal function deterioration after CTU. 7 days later after CTU, the patient underwent bilateral ureteroscopy (URS) and retrograde pyelography (RP) using iohexol contrast. Ten milliliters of contrast medium was injected bilaterally into the collecting system via ureteral catheter. The procedure confirmed right hydronephrosis due to a retrocaval ureter but found no evidence of urolithiasis or malignancy to account for the hematuria. 

Although the patient remained hemodynamically stable during the procedure, his renal function deteriorated significantly within 48 hours postoperatively (Cr: 3.51 mg/dL, eGFR: 16.9 mL/min/1.73 m²). The creatinine level peaked on postoperative day (POD) 9 at 4.29 mg/dL (eGFR: 13.3 mL/min/1.73 m²), consistent with KDIGO stage 3 AKI. The clinical course was complicated by poor oral intake, oliguria (urine output decreased to 550 mL/day starting on POD 2), metabolic acidosis, and dyspnea. Notably, the patient reported no flank pain. AKI workup including renal ultrasound showed no new hydronephrosis, urinalysis revealed no hematuria, pyuria, or urinary casts, and medication review confirmed no nephrotoxic drug exposure or new medications administered during the hospital course.  

We managed the patient with supportive management including intravenous fluid hydration, sodium bicarbonate for acidosis, and strict monitoring of fluid balance. Urine output returned to the patient's baseline (2000 mL/day) by POD 15, accompanied by an improvement in renal function (Cr: 3.2 mg/dL; eGFR: 19 mL/min/1.73 m²). By POD 18, prior to discharge, his creatinine had further improved to 1.92 mg/dL (eGFR: 34.8 mL/min/1.73 m²). At the outpatient follow-up on POD 31, his creatinine level had nearly returned to baseline (Cr: 1.45 mg/dL; eGFR: 48.7 mL/min/1.73 m²) 

Discussion:

Reflex anuria is a rare but clinically relevant cause of AKI following retrograde pyelography. In this case, the clinical course and literature review support RA as the most likely mechanism rather than contrast-induced nephropathy, particularly because bilateral oliguria developed abruptly after bilateral instrumentation and in the absence of extravasation. The presence of a retrocaval ureter may have promoted pyelotubular backflow and increased intrapelvic pressure, thereby contributing to reflex and pressure-mediated renal shutdown. Review of previously reported cases suggests that most patients recover with conservative management, although temporary hemodialysis may be necessary in selected cases. This case highlights that RA should remain an important differential diagnosis in patients who develop anuria and AKI after retrograde pyelography.

Conclusion:

  This case serves as a critical reminder for clinicians that retrograde pyelography, though generally considered safer for the kidneys than intravenous contrast can still trigger profound AKI through reflex mechanisms. Early recognition of RA and supportive management are essential for a successful recovery.