SEVERELY ENCRUSTED POLYURETHANE URETERAL STENTS: MANAGEMENT AND ANALYSIS OF POTENTIAL RISK FACTORS IQBAL SINGH, N. P. GUPTA, A. K. HEMAL, M. ARON, A. SETH, AND P. N. DOGRA ABSTRACT Objectives. To review the management of heavily encrusted and stuck JJ ureteral stents. We report our experience and review current published reports in managing heavily encrusted and stuck JJ stents, the guidelines for management, and the prevention of such problems. Methods. We reviewed our stent records from January 1994 to December 2000 and analyzed our stent complications and their final outcome. Fifteen patients had heavily encrusted and stuck stents. Of these, 14 were encountered in patients with a sizable stone burden (400 to 650 mm 2 ) and 1 occurred in a patient with malignant ureteral obstruction. Sandwich combinations of multiple extracorporeal shock wave lithotripsy/ traction and endourologic procedures were used to render them stone and stent free. The stent was examined and the encrustation was analyzed by x-ray crystallography. Results. Of 15 patients, 13 were available for evaluations; 1 patient was lost to follow-up and 1 patient died. The average stone burden was 625 mm 2 . The encrustation was localized to the upper end in eight and to the lower and upper end in three. In 4 cases, the entire stent was encrusted, and the lumen was occluded in 12. All 13 patients with stuck, fragmented, and encrusted stents were rendered stone and stent free; 2 of the 13 had clinically insignificant residual stones (less than 2 mm). Calcium phosphate and monohydrate stones were the most commonly encountered stone encrustations. Conclusions. Stent encrustation is one of the most serious complications of polyurethane JJ stents. Multi- modal endourology should form the cornerstone of therapy for heavily encrusted stuck stents. It is important to maintain an efficient computerized stent log under the direct supervision of a physician. Patients with probable risk factors should be monitored even more frequently to avoid mishaps and morbidity. UROLOGY 58: 526–531, 2001. © 2001, Elsevier Science Inc. W ith the widespread use of indwelling ureteral stents by urologists to provide urinary diver- sion, to relieve ureteral obstruction of diverse eti- ologies, and to provide postoperative drainage, problems relating to their use have also increased. No guidelines exist for successfully managing these potentially serious problems. Despite recent innovations and improvement in stent design and materials, serious complications still occur. Al- though the search for an ideal stent continues, we still cope with problems of stent migration, occlu- sion, encrustation, breakage, and stone forma- tion. 1–6 Severe encrustation and stone formation in in- dwelling ureteral stents remains a distressing prob- lem that can lead to severe morbidity and life- threatening urosepsis if not followed up and managed carefully. We present our series of pa- tients with retained, heavily encrusted stents. An algorithm is suggested to classify and manage such encrusted and stuck stents. MATERIAL AND METHODS A retrospective review and study of all case records related to stent encrustation was carried out from 1994 to 2000 in our department. The stone burden was defined by multiplying the width of encrustation by its length expressed as square milli- meters. The encrustations were graded as mild (less than 100 mm 2 ), moderate (100 to 400 mm 2 ), and severe (greater than 400 mm 2 ). Thus, a 26-cm-long, completely encrusted stent with a 3-mm-wide encrustation corresponds to a stone burden From the Department of Urology, All India Institute of Medical Sciences, New Delhi, India Reprint requests: N. P. Gupta, M.D., Department of Urology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India Submitted: November 20, 2000, accepted (with revisions): June 11, 2001 ADULT UROLOGY © 2001, ELSEVIER SCIENCE INC. 0090-4295/01/$20.00 526 ALL RIGHTS RESERVED PII S0090-4295(01)01317-6