Imaging of double J ureteral stents - what to look for?

Transcription

1 Imaging of double J ureteral stents - what to look for? Poster No.: C-1181 Congress: ECR 2014 Type: Educational Exhibit Authors: V. Urban, M. Djosev, J. Ilic, G. Lukic, T. Nastasic, S. M Arsenovic, B. Begenisic, N. Terzic, D. Lalosevic ; Belgrade/RS, 2 3 Belgrad/RS, Beograd/RS Keywords: Obstruction / Occlusion, Stents, Ultrasound, Plain radiographic studies, Urinary Tract / Bladder, Kidney DOI: /ecr2014/C-1181 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 46

2 Learning objectives The aim of this exhibit is to review radiological findings in various clinical settings in patients with double J ureteral stents - correct position, malpositions, complications, monitoring and possible findings during passage of renal calculi. Background Double J ureteral stents are commonly used for keeping a ureter patent. Main indications include treatment of urinary calculosis, prevention of complications following endourologic and open surgical procedures, treatment of extrinsic or intrinsic obstruction, urinary leaks etc. Since the stent is a foreign body, it may cause patient discomfort, bacterial colonisation and deposition of urine constituents. Depending on the clinical setting, the stent may be placed temporarily or permanently. In the latter case, regular replacements are necessary to prevent complications associated with long indwelling times. Stents are 1) usually replaced after 3 to 6 months. Radiological examinations are used to assess the position of the stent after placement, for monitoring the stent and stone passage, and for diagnosing suspected complications. Complications may result from incorrect placement or may develop in patients with a correctly placed stent, and include: migration, trauma, infection, encrustation, stent fracture etc. Findings and procedure details A correctly placed double J stent should have both ends curled in pigtail form, the proximal one in renal pelvis (loop oriented laterally) and the distal one in urinary bladder (loop preferably on the ipsilateral side to minimise irritative bladder symptoms). Page 2 of 46

3 Fig. 1: Correctly positioned double J stent. References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS The stent should be of adequate length - too short a stent may easily migrate, and too long a stent may cause irritative symptoms. Sometimes one double J stent cannot allow Page 3 of 46

4 sufficient flow, so two stents may be placed in the same ureter (usually in cases of severe 2) extrinsic obstruction). Page 4 of 46

5 Fig. 2: Two double J stents placed in the left ureter. The patient had a pyelocutaneous fistula after partial left nephrectomy and adrenalectomy due to malignancy. The right kidney had been removed several years before. References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS KUB radiography is the first-line modality in evaluation of stent positioning and/or complications. Fluoroscopy may be used during insertion. Ultrasound may be used for a more detailed examination of the intrarenal and intravesical ends as well as for evaluation of complications. Also, double J stents may facilitate visualisation of ureters on ultrasound since they can be easily identified as echogenic double lines. CT may be used in case of complications. Stents may be incorrectly placed initially or migrate later. Page 5 of 46

6 Fig. 3: Proximal end in the upper calyx (verified on ultrasound). References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS Ureteral malformations or strictures are common causes of a malpositioned stent. Page 6 of 46

7 Fig. 4: Double J stent placed too low - kinking of pyeloureteric junction. References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS Page 7 of 46

8 Fig. 5: Double J stent forms a loop in a strictured ureter. References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS Page 8 of 46

9 Fig. 6: Megaureter: convoluted proximal end of double J stent in proximal ureter. References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS Distal migration is more common than proximal. Stents may migrate entirely into the bladder or even be passed through the urethra. Page 9 of 46

10 Fig. 7: Distal migration of a double J stent. References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS Page 10 of 46

11 Fig. 8: Double J stent migrated into the bladder. References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS Page 11 of 46

12 Fig. 9: Double J stent migrated into the urethra. References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS Fig. 10: Double J stent migrated proximally and its proximal end got impacted in the kidney. The distal end was inside the ureter. Endoscopic extraction was attempted, Page 12 of 46

13 but the distal fragment broke off. The stent was finally removed endoscopically three months later, its proximal end was partially calcified. References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS When evaluating stent position, one should bear in mind the possibility of an anatomic variation that can make the stent look improperly placed. Page 13 of 46

14 Fig. 11: Kinking of the right ureter. Double J stent correctly placed. References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS If placed too high, stents might penetrate the renal parenchyma or the renal capsule, and cause urinomas, abscesses or hematomas. If the proximal end on a KUB radiograph Page 14 of 46

15 projects outside of the kidney, an ultrasound or CT examination should be immediately performed to evaluate possible complications. Fig. 12: Fausse route - double J stent perforated the right ureteral wall 4 cm above the ureterovesical junction, crossing the midline to the contralateral side. Page 15 of 46

16 References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS Fig. 13: Double J stent placed too high and perforated the ureter. The proximal end is below the diaphragm, and the distal one is almost entirely in the ureter. References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS Page 16 of 46

17 Fig. 14: Double J stent placed too high perforated the renal cortex with consequent hematoma and abscess formation, visible on ultrasound (yellow arrow - stent; white arrow - abscess). References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS If the proximal end projects inside the kidney, but close to its surface, an ultrasound examination should be performed to see whether it penetrates the renal parenchyma or just enters a calyx. Page 17 of 46

18 Fig. 15: KUB: Proximal tip of the stent projects almost to the renal border (red arrow). US: The stent (yellow arrow) is seen penetrating the renal cortex and reaching the capsule. References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS If a stent is left too long, urine constituents may deposit on its surface leading to encrustation. A encrustated stent may fracture spontaneously or while being removed. 1) Encrustation develops more often on the extraureteric portions. It usually presents as increased radioopacity of the stent and/or radioopaque deposits. Page 18 of 46

19 Fig. 16: Encrustation of double J stent nine months after insertion - the whole stent is of uniformly higher opacity. References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS Page 19 of 46

20 Fig. 17: Encrustated intravesical end. References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS However, encrustation, even when severe, need not be visible on KUB radiographs! Page 20 of 46

21 Fig. 18: "Forgotten stent" - double J stent 2,5 years after insertion. The stent was partially encrustated. No definitive radiological signs of encrustation. Consequent atrophy of the left kidney. References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS Page 21 of 46

22 Ultrasound may be helpful in detecting early encrustation, especially of the intravesical 3) end. Twinkling artifact on colour-doppler sonography may increase diagnostic accuracy. Double J stents are commonly used for management of urolithiasis. Main indications in that aspect are intractable pain, infected pyelonephrosis, impaired renal function due 4) to obstruction and after ESWL or endoscopic procedures. They are also helpful in monitoring of passage of stones and stone fragments. Page 22 of 46

23 Fig. 19: Double J stent placed too high, the distal end is in the ureter. "Steinstrasse" in the distal ureter after unsuccessful ureterorenoscopic lithotripsy. References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS Page 23 of 46

24 It is important to thoroughly evaluate the whole length of the stent, as stone fragments may appear very faint. Fig. 20: Double J stent before and after ESWL treatment of kidney stone. Left: Before ESWL. Middle and right: After ESWL - stone fragments in the distal ureter: two small ones prevesically (yellow arrow), a phlebolith (green arrow) and a very discreet opacity which proved to be the largest stone fragment (red arrow). References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS Sometimes, a large or impacted stone may impede stent insertion, resulting in an improperly placed or migrated stent. Page 24 of 46

25 Fig. 21: Double J stent forms a loop distally to a large obstructing stone. References: Clinical center "Dr Dragisa Misovic - Dedinje" - Belgrade/RS Images for this section: Page 25 of 46

26 Fig. 2: Two double J stents placed in the left ureter. The patient had a pyelocutaneous fistula after partial left nephrectomy and adrenalectomy due to malignancy. The right kidney had been removed several years before. Page 26 of 46

27 Fig. 17: Encrustated intravesical end. Page 27 of 46

28 Fig. 3: Proximal end in the upper calyx (verified on ultrasound). Page 28 of 46

29 Fig. 5: Double J stent forms a loop in a strictured ureter. Page 29 of 46

30 Fig. 9: Double J stent migrated into the urethra. Page 30 of 46

31 Fig. 14: Double J stent placed too high perforated the renal cortex with consequent hematoma and abscess formation, visible on ultrasound (yellow arrow - stent; white arrow - abscess). Page 31 of 46

32 Fig. 16: Encrustation of double J stent nine months after insertion - the whole stent is of uniformly higher opacity. Page 32 of 46

33 Fig. 10: Double J stent migrated proximally and its proximal end got impacted in the kidney. The distal end was inside the ureter. Endoscopic extraction was attempted, but the distal fragment broke off. The stent was finally removed endoscopically three months later, its proximal end was partially calcified. Page 33 of 46

34 Fig. 11: Kinking of the right ureter. Double J stent correctly placed. Page 34 of 46

35 Fig. 12: Fausse route - double J stent perforated the right ureteral wall 4 cm above the ureterovesical junction, crossing the midline to the contralateral side. Page 35 of 46

36 Fig. 8: Double J stent migrated into the bladder. Page 36 of 46

37 Fig. 19: Double J stent placed too high, the distal end is in the ureter. "Steinstrasse" in the distal ureter after unsuccessful ureterorenoscopic lithotripsy. Page 37 of 46

38 Fig. 6: Megaureter: convoluted proximal end of double J stent in proximal ureter. Page 38 of 46

39 Fig. 4: Double J stent placed too low - kinking of pyeloureteric junction. Page 39 of 46

40 Fig. 20: Double J stent before and after ESWL treatment of kidney stone. Left: Before ESWL. Middle and right: After ESWL - stone fragments in the distal ureter: two small ones prevesically (yellow arrow), a phlebolith (green arrow) and a very discreet opacity which proved to be the largest stone fragment (red arrow). Fig. 15: KUB: Proximal tip of the stent projects almost to the renal border (red arrow). US: The stent (yellow arrow) is seen penetrating the renal cortex and reaching the capsule. Page 40 of 46

41 Fig. 1: Correctly positioned double J stent. Page 41 of 46

42 Fig. 18: "Forgotten stent" - double J stent 2,5 years after insertion. The stent was partially encrustated. No definitive radiological signs of encrustation. Consequent atrophy of the left kidney. Page 42 of 46

43 Fig. 13: Double J stent placed too high and perforated the ureter. The proximal end is below the diaphragm, and the distal one is almost entirely in the ureter. Page 43 of 46

44 Fig. 21: Double J stent forms a loop distally to a large obstructing stone. Page 44 of 46

45 Fig. 7: Distal migration of a double J stent. Page 45 of 46

46 Conclusion Radiological methods are leading tools for evaluating inserted double J ureteral stents. They can provide valuable information regarding positioning and monitoring of indwelling stents, stone passage, as well as possible complications and their follow-up. Personal information Department of Radiology University Hospital Centre "Dr Dragiša Mišovi# - Dedinje" Heroja Milana Tepi#a Beograd Serbia References 1. Dyer RB, Chen MY, Zagoria RJ, Regan JD, Hood CG, Kavanagh PV. Complications of Ureteral Stent Placement. RadioGraphics 2002; 22: Liu JS, Hrebinko RL. The use of 2 ipsilateral ureteral stents for relief of ureteral obstruction from extrinsic compression. J Urol Jan; 159(1): Trillaud H, Pariente J, Rabie A, Grenier N. Detection of Encrusted Indwelling Ureteral Stents Using a Twinkling Artifact Revealed on Color Doppler Sonography. AJR 2001;176: Chew BH, Denstedt JD. Access, Stents, and Urinary Drainage IN: Nakada SY, Pearle MS. Advanced Endourology The Complete Clinical Guide. Humana Press, 2006:19-42 Page 46 of 46