Bilateral complete ureter duplication presenting with hydronephrosis and spontaneous stone passage in a 25-year-old male: A rare case report

Abstract

Ureteric duplication is a rare anomaly in the urinary tract, with an incidence of 0.5% to 3%. Bilateral double ureters are even rarer, occurring in 1 of 500 individuals. A 25-year-old man presented with right flank pain and nausea. Physical examination revealed tenderness at the right renal angle. Urinalysis demonstrated microscopic hematuria, and Ultrasound showed enlargement in the lower pole of the right kidney, while the upper pole appeared normal. Intravenous pyelography confirmed bilateral complete ureter duplication. However, after a week of observation, a 5 mm calcium oxalate stone was passed, and this event demonstrated the underlying cause of hydronephrosis in the lower pole of the right kidney. Bilateral complete ureter duplication is a rare anomaly in the urinary tract. To our knowledge, the presence of bilateral complete ureter duplication with a single stone in the right limb of the right double ureter is a unique case that has not been reported in the existing literature.

Introduction

Ureteric duplication is a urinary tract anomaly with an incidence of 0.5% to 3%. Ureteral duplication is more prevalent in female than male, with a higher prevalence in Caucasian females [1]. Bilateral double ureters occur in 1 of 500 people, which is rarer than ipsilateral double ureters [2,3]. Here, we present a male with bilateral complete double ureters, who has a 5 mm calcium oxalate stone in the right limb of the right double ureter. According to our knowledge, this is the first case report in the existing literature.

Case presentation

We present a case of a 25-year-old male who presented to the urology department with right flank pain and nausea. The patient had no prior medical or surgical history. Physical examination revealed right renal angle tenderness, and urinalysis demonstrated microscopic hematuria. Renal function tests and complete blood count were normal. Ultrasound revealed hydronephrosis in the lower pole of the right kidney, while the upper pole appeared normal. This asymmetry between the upper and lower poles raised suspicion of an anomaly in the urinary tract. Intravenous pyelography (IVP) confirmed bilateral complete ureter duplication as the underlying cause of the observed kidney asymmetry, providing a definitive diagnosis for the patient's symptoms (see Fig. 1). Initial management involved a conservative approach, with close monitoring and symptomatic treatment of pain and nausea. However, after a week of observation, a 5 mm calcium oxalate stone was passed, which explained the hydronephrosis in the lower pole of the right kidney. The passage of the stone resolved the patient's symptoms without the need for invasive intervention. Follow-up assessments were scheduled to monitor the patient's renal function and urinary tract health, and potential for further stone formation.

Fig. 1.

The figures showed bilateral complete ureteral duplication; (A) 10-minute postinjection, (B) 15-minute postinjection, (C) 20-minute postinjection, the red arrows demonstrated hydronephrosis in the lower pole of the right kidney, while the upper pole appeared normal.

Discussion

This case presents a very rare congenital ureteral disorder, characterized by bilateral complete ureteral duplication, and with a single stone located in the right limb of the right double ureter. Double ureter refers to the presence of 2 separate ureters on the same side of the body [2]. This can occur in a complete or incomplete form [2]. Bilateral complete ureteral duplication is a rare abnormality in the urinary tract that is more common in females [1,3]. Unilateral ureteral duplication has been observed in up to 0.8% of individuals in the United States during autopsies, while bilateral duplication is found in 0.16%-0.32% of the population [4]. The ureteric bud emerges from the mesonephric duct and grows vertically until it fuses with the metanephric blastoma, which gives rise to the adult kidney and ureter in the future [5]. The underlying embryological basis for a duplex kidney with complete ureteral duplication can be explained by the separate formation of 2 ureteral buds from a single mesonephric duct [1,5]. The Union of 2 proximal branches of ureter occur before inserting into the bladder in partial duplication, while 2 ureters insert separately into the bladder in complete duplication [1], The complete duplication is a rarer type, and in cases of bilateral and complete duplication, all 4 ureters may open orthotopically on the bladder trigone [1,3]. The upper pole ureter is more susceptible to obstruction due to its abnormal insertion, whereas the lower pole ureter is more likely to cause reflux as it forms a shorter tunnel into the bladder. However, patients may also present with hematuria, flank or abdominal pain, and other congenital defects such as the ectopic ureter, with associated complications such as urolithiasis, vesicoureteral reflux, urine incontinence, and urolithiasis. Urinary calculi are often due to relative stasis of urine but may occur due to factors unrelated to the duplication [1,3]. After birth, ultrasound remains a valuable tool for detecting abnormalities in the urinary system, and unilateral duplication can be identified by observing asymmetry. Segmental isolated hydronephrosis may suggest incomplete duplication, complete duplication demonstrated nonuniform hydronephrosis between upper and lower poles, with uniformity being inconclusive. Complete duplication without obstruction may not be easily detected on ultrasound. Intravenous pyelography helps to confirm the level of convergence between the ureters, if a diagnosis of complete versus partial duplication remains elusive [4].

Conclusion

Bilateral complete ureter duplication is a rare urinary tract anomaly that can be diagnosed via ultrasound during pregnancy. However, in cases where there is asymmetrical hydronephrosis between the upper and lower poles, it suggests potential anomaly within the urinary tract, and it is crucial to perform intravenous pyelography for confirming the diagnosis.

Ethics approval and consent to participate

Not applicable.

Availability of data and materials

Not applicable.

Author contributions

Y.A. Conception, Organization, Data collection, Writing - original draft, Writing - review and editing. A.R. Writing - original draft, Writing - review and editing. H.A. Data collection, Writing - original draft, Writing - review and editing. M.S. Data collection, Writing - review and editing, Supervision, Investigation.

Patient consent

Written informed consent was obtained from the patient for publication and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.