The forgotten ureteric stent

Abstract

A 79-year-old woman presented to the emergency department with malaena, poor appetite and weight loss. On general examination she was cachectic and pale. Physical examination revealed a suprapubic mass, and on rectal examination a large well-defined hard non-tender mass was palpated anteriorly. Blood tests revealed significant anaemia with a haemoglobin level of 47 g/L. Contrast enhanced computer tomography revealed a right sided ureteric stent in situ and a large well-defined bladder calculus, with measurements of 8 × 5.5 cm. Asymmetric marked mural thickening of the bladder wall was also present. The proximal ureteric stent had migrated down the right renal collecting system to the dilated right upper ureter (Fig. 1). Plain abdominal radiography also showed the bladder calculus and calcified ureteric stent (Fig. 2). The residual oral contrast from the earlier CT scan is also seen in the bowel lumen in the plain abdominal radiograph. Contrast enhanced computer tomography revealing the proximal ureteric stent (arrowed) which has migrated down the right renal collecting system into the dilated right upper ureter and the large well defined bladder calculus. Plain abdominal radiography showing the bladder calculus and ureteric stent in situ. The bowel lumen contains residual oral contrast from the earlier CT scan. Her anaemia was investigated with a gastroscopy that revealed a small area of gastric ulceration. This was biopsied and was confirmed as a gastric adenocarcinoma. Staging investigations revealed no evidence of metastatic disease. The patient declined active management. She continued to be troubled with significant urinary symptoms. Her past medical history included a bladder carcinoid that presented as haematuria 2 years earlier. This rare tumour of the urinary bladder recurred following initial transurethral resection of the bladder tumour. Consequently, she underwent partial cystectomy and during this procedure, a right sided ureteric stent was inserted. The patient was subsequently lost to follow-up and the ureteric stent had remained in situ for 27 months. As a staged procedure, she underwent extracorporeal shock wave lithotripsy to the proximal ureteric stent followed by open cystolithotomy and right rigid ureteroscopy and basket stone removal of the stone fragments. The bladder calculus, ureteric stent and associated stone were successfully removed intraoperatively (Fig. 3). Inspection of the bladder mucosa confirmed no tumour recurrence. The patient was stent and stone free after the procedure. Bladder calculus and ureteric stent following operative removal. Ureteric stents have become an essential part of urological practice since their introduction in 1978. The ureteric stent has an important function in management of urinary stone disease, genitourinary trauma, renal transplantation, genitourinary oncology, reconstructive surgery and ureteric obstruction secondary to extrinsic compression.1 Although commonplace in modern urology, ureteric stents are not without complication. Patients frequently experience irritative urinary symptoms, flank pain, suprapubic discomfort and occasional haematuria.2 Other complications include urinary tract infections, migration, forgotten or retained stent, encrustation, blockage and bladder erosion.2 This case highlights the preventable complication of retained ureteric stent and its morbidity if the stent becomes calcified. Monga et al. reported a series of 22 patients with forgotten stents that were left in situ for greater than 6 months. Of those patients with retained ureteric stents, 68% had calcified stents, 45% fragmented stents and 14% had calcified and fragmented stents.1 The incidence of stent encrustation increases with the duration that the stent remains in situ. El-Faqih et al. evaluated 299 stents in patients with calculi and noted an encrustation rate of 9.2% before 6 weeks, 47.5% from 6–12 weeks and 76.3% after 12 weeks.3 Although encrusted retained ureteric stents can be removed in a single procedure, often the management requires multiple modalities and several procedures to render patients stone and stent free.4 Monga et al. found that multiple procedures were required in 19% of patients and more recently, Borboroglu and Kane found that 50% of patients required more than one session to achieve a stone and stent free state.5 Common management modalities have their limitations. Extracorporeal shock wave lithotripsy is often unable to fully fragment the extensive calculous burden associated with retained stents. Also percutaneous nephrolithotomy does not address the vesical end of ureteric stent calcification.6 In this case both ends of the stent were calcified. As a result, the patient received extracorporeal shock wave lithotripsy to the upper curls the day prior to undergoing open cystolithotomy. It successfully fragmented the proximal ureteric stent calcification enabling the ureteric stent to be easily removed following the distal ureteric stent and bladder calculus removal. This case clearly demonstrates problems associated with ureteric stents and draws attention to the need for systems such as a registry of stent placement so that such events can be prevented.