PMC5734148_01
(A) Upright KUB showing a DJ stent with radiopaque shadow in the left renal coil with the distal coil lying near the contralateral sacroiliac joint with the shaft of DJ stent crossing the midline at L4 lumbar vertebral level. (B) Three-dimensional reconstructed contrast-enhanced computed tomogram KUB with urography showing upper end of the DJ stent inside the renal pelvis with surrounding encrustations and the shaft of the DJ stent emerging out of the upper ureter at L3 vertebral level and crossing the midline at L4 vertebral level. DJ, Double-J; KUB, kidney urinary bladder radiograph.
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To our surprise, an upright kidney, urinary, and bladder radiograph (KUB) revealed a DJ stent with radiopaque shadow in the left renal coil and the distal coil lying near the contralateral sacroiliac joint with the shaft of DJ stent crossing the midline (Fig. 1A). However, the shaft of the DJ stent found emerging out of the upper ureter at the level of third lumbar (L3) vertebra, into the retroperitoneum, crossing the midline at the level of fourth lumbar (L4) vertebra, with the distal coil lying at the level of right sacral ala (Fig. 1B).
(A) Left retrograde pyelogram showing injected contrast reaching the PCS. (B) Intraoperative nephroscopic view showing encrustations of the proximal coil of the stent lying within the PCS. (C) The retrieved DJ stent with upper third stained dark (the part lying in the urinary tract) and lower two-thirds appeared clean (the part lying in the retroperitoneum unexposed to urinary environment). PCS, pelvicaliceal system.
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The patient underwent cystoscopy with left retrograde pyelogram, which revealed injected contrast reaching the PCS (Fig. 2A). In view of large encrustations around the renal coil of the DJ stent, we did a PCNL to dislodge the encrustations (Fig. 2B). The proximal third of the retrieved DJ stent lying inside the urinary tract stained dark, whereas the distal two-third lying in the retroperitoneum appeared clean and without encrustations (Fig. 2C).