Ureteropelvic Junction Obstruction (UPJO) syndrome: imaging with Multidetector CT (MDCT) prior to minimally invasive treatment Poster No.: C-1753 Congress: ECR 2011 Type: Scientific Exhibit Authors: E. Skondras, P. Kraniotis, P. Zabakis, P. Kallidonis, E. Liatsikos, T. Petsas, C. Kalogeropoulou; Patras/GR Keywords: Urinary Tract / Bladder, Kidney, CT, Computer Applications-3D, Pyelography DOI: 10.1594/ecr2011/C-1753 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. www.myesr.org Page 1 of 13
Purpose Uretero-pelvic junction obstruction (UPJO) syndrome is an uncommon condition with varied etiology and unpredictable natural history. Primary UPJO can be divided in intrinsic and extrinsic. Intrinsic primary UPJO is usualy depicted in neonatal age due to a intrinsic congenital patholgy of the junction and is the most common cause of antenatal hydronephrosis. Extrinsic primary UPJO usually happens in adolescents and is usually attributed in extrinsic pressure of the junction due to vascular variations. The term "crossing vessel" means an accessory renal artery or vein in contact with the junction. Secondary UPJO is usually caused by renal stone, vesicureteral reflux or iartrogenic procedures. If untreated, UPJO syndrome can create obstructive nephropathy and renal impairment in some cases. Imaging plays an important role in UPJO syndrome with a twofold usage: diagnosis on the one hand and pretreatment planning on the other especially if a minimal invasive treatment method has been selected. Minimal invasive surgical techniques in urology (laparoscopic or endoscopic procedures) offer crucial benefits in comparison with open surgery, such as minimal morbidity, high success rates, shorter hospitalization, decreased operative time, less post-operative pain and quicker return to normal daily activity. However, accurate preoperative evaluation of the patients is necessary in order to minimize decreased success rates or complications in selected patients with anatomical vasculature variants. Our objective was to evaluate the utility of MDCT imaging in determining the most suitable surgical approach in UPJO. Our multidisciplinary study consisted of two parts: the preoperative assessment of patients with UPJO syndrome with multidetector CT urography and the use of newer treatment options when feasible with less morbidity. Satisfactory imaging - surgical correlation as well as modification of the treatment planning according to imaging findings was estimated in all cases. Page 2 of 13
Images for this section: Fig. 0: Left kidney UPJO syndrome in coronal Multi Planar Reconstruction (MPR) Page 3 of 13
Methods and Materials We prospectively evaluated 22 patients (10 male), with a mean age of 44 years, who were submitted to preoperative imaging with MDCT, during the last two years. All patients had clinical suspicion of UPJO, hydronephrosis on ultrasonography and laboratory evidence of impaired renal function. The examination protocol consisted of pre and post contrast medium acquisition using a 16x MDCT scanner. Patient preparation consisted of oral hydration prior to examination resulting in optimal distention of ureters. Contrast acquisition was performed in the corticomedullary and nephrographic phase, sparing excretory phase in patients < 40years, except in selected cases. Post-processing analysis included maximum intensity projection (MIP) and volume rendering (VR) in a dedicated workstation. The following parameters were recorded: 1. renal morphometrics 2. pelvic dimensions (greatest dimension in axial plane) 3. presence of crossing vessels (CVs), its type (artery or vein) and anatomic relations of CV relative to the ureteropelvic junction (UPJ). Page 4 of 13
Images for this section: Fig. 0: LT kidney UPJO and crossing vein (MPR in oblique plane) Page 5 of 13
Fig. 0: RT UPJO and crossing accessory artery (MPR in coronal plane) Fig. 0: RT kidney accessory artery causing UPJO with Volume Rendering technique (VR) Page 6 of 13
Fig. 0: Two accessory arteries in LT kidney UPJO, the inferior one is in close proximity with junction (VR technique) Page 7 of 13
Fig. 0: The same patient with Fig.4 but with MIP technique Page 8 of 13
Results Parenchymal width was within normal range in all patients but four. Pelvic dimensions were increased in the abnormal kidneys with an average of 35.13 mm compared to the contralateral normal kidneys (12.10 mm). Fourteen crossing vessels were detected in total in 13/22(59.10%) patients. These included 7/14(50%) arteries and 7/14(50%) veins. Topographically 3/14(21.43%) vessels were anterior, 6/14(42.85%) posterior, 3/14(21.43%) medial and 2/14(14.29%) lateral to the UPJ. Two patients had bilateral UPJO. Incidental findings included 6 cases of nephrolithiasis and 1 renal tumor. Patients with crossing vessels were excluded from endourologic treatment and were treated with laparoscopic or open surgery. Page 9 of 13
Images for this section: Fig. 0: Table 1 Fig. 0: Table 2 Page 10 of 13
Conclusion The decision-making process regarding the surgical treatment modality of choise in adult patients with UPJO is depending on many parameters. Multi-phase MDCT constitutes a comprehensive examination of the kidneys and the collecting system and can provide a wealth of information regarding anatomical and functional aspects of the urinary system thus facilitating the selection of optimal surgical treatment. In our study the surgical plan was altered whenever crossing vessels were depicted, an important consideration that must be taken into account prior to minimal invasive techniques. Page 11 of 13
References 1. Radiographics. 2005 Jan-Feb;25(1):121-34. Adult ureteropelvic junction obstruction: insights with three-dimensional multi-detector row CT. Lawler LP, Jarret TW, Corl FM, Fishman EK. 2. Ann R Coll Surg Engl. 2007 Mar;89(2):153-6. The role of percutaneous endopyelotomy for ureteropelvic junction obstruction. Rukin NJ, Ashdown DA, Patel P, Liu S. 3. Curr Urol Rep. 2007 Mar;8(2):111-7. Pathophysiology and treatment of ureteropelvic junction obstruction. Williams B, Tareen B, Resnick MI. 4. Eur J Radiol. 2007 Jan;61(1):170-5. Epub 2006 Oct 17. Multidetector computed tomography arteriography in the preoperative assessment of patients with ureteropelvic junction obstruction. 5. Eur Radiol. 2006 Nov;16(11):2603-11. Epub 2006 Mar 28. Multidetector CT of the kidney. Coppenrath EM, Mueller-Lisse UG. Page 12 of 13
Personal Information Evangelos Skondras Radiology Department University Hospital of Patras, Greece email: vaggoul@gmail.com telephone: +302610999983 Page 13 of 13