Duplex kidney anomalies and associated pathology: a single centre retrospective review

Abstract

Background: Duplex kidneys are common developmental renal anomaly with an incidence of 1% in healthy adult population. Adult individuals may present as non-functional moiety, calculus disease or an incidental finding. Duplex kidney is defined as a renal unit comprised of two pelvicalyceal systems. Based on the degree of fusion, it can present as bifid renal pelvis, partial ureteric duplication (Y-shaped ureter), incomplete ureteric duplication with ureters joining near or in bladder wall (V-shaped ureter) and complete ureteric duplication with separate ureteric orifices. The purpose of this study is to retrospectively review the various duplex kidney anomalies and associated pathology. Methods: This is a retrospective study, performed at Department of Urology, Gauhati Medical College Hospital, a tertiary centre, from September, 2018 to August, 2019. Preoperative imaging, plain intravenous urography or computed tomography intravenous urography was done. Results: 29 patients were diagnosed with variants of duplex kidney anomaly. It includes right side, left side and bilateral anomalies. Among all the patients 4 had incidental findings. 16 patients had associated renal or ureteral calculus. 5 patients had associated ureteropelvic junction obstruction while 1 patient had ureterovesical junction stricture. We found single patient in each group of duplex kidney anomaly associated with non-functional moiety with renal cell carcinoma, ureterocele with urothelial malignancy and horseshoe kidney with ureteropelvic junction obstruction respectively. Conclusions: Duplex kidney anomaly in most individuals is of no clinical significance. High index of suspicion along with good quality imaging can accurately detect specific anomaly and associated condition.Cite this article as: Sarma D, Pratihar SK, Rajeev TP, Barua SK, Bagchi PK, Phukan M. Duplex kidney anomalies and associated pathology: a single centre retrospective review. Int Surg J 2020;7:76-82.

Duplex collecting system with renal malrotation: an unusual combination

“…This condition is the most common congenital abnormality of the urinary tract. 1 Most patients are asymptomatic throughout their lives, but it can also cause conditions like vesicoureteral reflux (VUR), incontinence, ureterocele or obstructive uropathy as well as renal parenchymal scarring or dysplasia and decreased renal function. 6 During fetal development, single ureteric bud arises from the mesonephric (Wolffian) duct that migrates to the metanephros (precursor of the kidney).…”

“…7.2% of individuals with urinary tract abnormalities were included in this. 1 Kidney malrotation is a rare case, more commonly present in men than women. Prevalence of renal malrotation is 1 in 2000 autopsies.…”

Multi Imaging Modality in Diagnosis of Unusual Giant Hydronephrosis of the Non Functioning Lower Moiety in A Partial Duplex Kidney with Distal Ureteric Stricture

“…It is a result of partial or total duplication of the ureteric bud. Depending on the degree of fusion, it can present as bifid renal pelvis, partial (incomplete) ureteric duplication with ureters joining proximally or near the bladder wall and complete ureteric duplication with separate ureteric orifices [7,8]. In complete duplex, the ureteral drainage pattern is normally governed by the Meyer-Weigert rule, predicting that the ureter of the upper part usually drains infero-medially into an ectopic location, and the lower ureter part usually drains supero-laterally to its normal insertion in the trigon [9,10].…”

Complete Duplex of the Left Ureter with Lower Moiety Hydronephrosis Secondary to Ureteral Stone in Adult

“…Ureteral duplications are a common congenital anomaly of the kidney and the urinary tract system [ 1 , 2 ]. It has an incidence rate of 0.8% in the healthy adult population, 0.3%–2.5% incidence in an autopsy, and 2–4% in patients investigated for urinary tract symptoms [ 3 ].…”