Pitfalls of the duplex system: the mystery of the missing stone

Abstract

A duplex ureter constitutes about 1% of the renal tract anomalies.A 39-year-old man presented with a 4-week history of left loin pain and microscopic haematuria. Investigation with a non-contrast CT KUB revealed a 6 mm non-obstructing calculus in the left distal ureter.Left ureteroscopy and lithotripsy was planned. However, ureteroscopy failed to identify the calculus. A double J ureteric stent was left in situ and the procedure abandoned in favour of further assessment with a CT urogram. Imaging surprisingly showed a left duplex ureter with the calculus in the non-stented ureter.Repeat ureteroscopy noted the second ureter opening within the distal intramural part of the stented ureter. The calculus was identified and laser lithotripsy performed. A double J stent was appropriately reinserted and removed 2 weeks later.Our case highlights the importance of contrasted imaging prior to performing ureteroscopy for calculus disease.

Obstructing calculus in a single limb of a duplicated ureter: A Recall of the surgical anatomy and the Variable Ureter Anomalies

“…So, in most of the patients with impacted ureteric stone of the duplicated ureter, similar to our case, most of the anomalies can be detected only in the theater during the procedure of ureteroscopic stone extraction. In such cases there is a high possibility for the ureteric anomaly to be missed and hence the calculus will not to be accessed [8]. Indeed in our search in the English medical literature many of the treated patients of the impacted calculus in a duplicated ureter in a single limb or in both limbs patient required a subsequent definitive further treatment [7,8,10].…”

“…In such cases there is a high possibility for the ureteric anomaly to be missed and hence the calculus will not to be accessed [8]. Indeed in our search in the English medical literature many of the treated patients of the impacted calculus in a duplicated ureter in a single limb or in both limbs patient required a subsequent definitive further treatment [7,8,10]. Usually this may prolong the hospital stay and consequently increase the cost of treatment.…”

“…Duplication of the ureter may be incomplete (bifid ureter) or complete in which each limb of the duplicate open separately in the bladder and this is a rare anomaly [6,7].The VUJ orifice of the limb which drain the upper renal moiety (the first limb of the duplicate) has ectopic insertion usually medial and inferior to the lower pole moiety ureter (the second limb of the duplicate) which has orthotopic insertion in the bladder (Weigert-Mayer law) [1]. The complete duplication is present in approximately in 1 from 125 individual [6].It is more common in females than males with a ratio of 2:1 [5].In the English literature few cases of calculi found in one limb or in the two limbs of the duplicated ureter [8,9]. More few cases reported with bilateral ureteric duplication in which stones were found in all of the limbs of the duplicate [10].…”

Obstruction of bifid ureter by two calculi

“…The fact that the ureteric bud divides prematurely before penetrating into metanephric blastema will result in duplex ureter. [ 1 ] There are 2 types of complete and incomplete duplex ureter. The incidence of incomplete duplex ureter, including 3 subtypes, such as proximal, middle, and distal, depending on the location that bifid ureters join a single unit, is 3 times more than the complete.…”

“…A duplex ureter occurs with an incidence of approximately 0.8% and is the most common anomaly, and calculus in the duplicated ureter is also a common entity. [ 1 ] Although asymptomatic patients with duplex ureter could be found incidentally by excretory urography, ultrosonography, computed tomography (CT), and magnetic resonance imaging (MRI), preoperative assessment of the anatomic variations and function of duplex renal and ureters is often difficult in symptomatic patients with urinary obstruction, vesicoureteral reflux, and urinary tract infection. [ 2 ] To our knowledge, there are very few case reports in literature documenting a patient with multiple calculi obstruction in bifid ureter, resulting in severe hydronephrosis of both moieties and urinary tract infection.…”