DECLARATIONSCompeting interestNone DeclaredFundingNone declaredEthical approvalWritten informed consent to publish the article was obtained from the patientGuarantorSDContributorshipSD is the main author, writing the case report and performing a literature review for the discussion. AV undertook and provided information on the surgical procedure and edited the manuscript.AcknowledgementsNoneDuplex kidneys are a rare presentation in adults. We report a case and literature review discussing the diagnostic difficulties.Case report Section:A 30-year-old-man who initially presented three years previously to the emergency department with right loin pain and a three-month history of haematuria. He reported no other urinary symptoms and was otherwise fit and well with no significant past medical history. Flexible cystoscopy was unremarkable and evaluation with ultrasound and a computed tomography (CT) scan demonstrated a large right-sided renal cyst (see Figure 1a), which was subsequently treated with laparoscopic marsupialization, draining 2.2 L. DownloadOpen in new tabDownload in PowerPointFigure 1 (a) Computed tomography (CT) scan demonstrating appearance similar to renal cyst. (b) CT scan postoperatively after successful heminephrectomy and ureterectomyThe patient was re-referred two years following this with recurrence of his right loin pain and a general feeling of discomfort. Investigation by a repeat CT scan revealed the presumed renal cyst was in fact a dilated non-functioning upper moiety and dilated ureter that traced downwards into the pelvis. The patient underwent excision of the non-functioning right upper pole moiety and megaureter using an open approach. Prior to incision the patient underwent cystoscopy and stenting of the lower pole normal ureter.A subcostal incision was used with retroperitoneal mobilization of the kidney and upper dilated segment. The cystic segment was opened and drained 2 L of cloudy urine. The dilated upper pole segment was then excised (see Figure 2). An oblique incision in the right iliac fossa was used for retroperitoneal mobilization of the grossly dilated ureter. As the dilated upper ureter ran close to the lower pole ureter, the distal end of the dilated ureter was divided to excise the ureter, leaving a ureteral stump. The postoperative period was uneventful and the patient was discharged home within five days. The stent in the lower pole ureter was removed endoscopically at routine follow-up and the patient has remained well. DownloadOpen in new tabDownload in PowerPointFigure 2 Remaining lower pole following open resection of dilated upper poleDiscussion Section:Duplex collecting systems are one of the most common congenital anomalies, with an incidence of 0.8%.1 It is bilateral in 20% of these and is more common in women than in men. Ureteral development begins at four weeks in the fetus with the ureteral bud (which determines the entire collecting system) branching from the mesonephric duct.2 The ureteric bud is absorbed into the bladder trigone, leaving the ureteric orifice in its normal position. If two ureteral buds arise, the caudal ureter drains the lower pole and the cephalic ureter drains the upper pole.3 The lower pole ureter implants early, leading to a shorter submucosal tunnel and an association with vesiocureteric reflux. The upper pole ureter can open anywhere between the lower pole ureter and the ejaculatory duct. Upper pole ureters are more susceptible to obstruction if associated with ureteroceles or ectopic insertion.3,4Most patients remain asymptomatic despite the relatively common incidence. Patients usually present in childhood, however, in rare instances can present as adults. Presentation can include recurrent urinary tract infections, flank pain, incontinence and haematuria.5 Duplex systems are occasionally found incidentally on abdominal examination or during surgery.6,7Diagnosis is usually made in childhood or antenatally, although it can be found in adulthood
展开▼
