World J Urol (2011) 29:199–204 DOI 10.1007/s00345-010-0612-9 T O P I C P A P E R The ﬁsh-hook conﬁguration of the distal ureter indicates bladder outlet obstruction due to benign prostatic hyperplasia Charalampos Mamoulakis • Thomas R. W. Herrmann • Klaus Ho¨fner • Matthias Oelke Received: 23 August 2010 / Accepted: 30 October 2010 / Published online: 16 November 2010 The Author(s) 2010. This article is published with open access at Springerlink.com Abstract Purpose The aim of this retrospective study was to evaluate in a historical series of patients whether mor- phological changes of the urinary tract imaged on intra- venous urography (IVU) are associated with clinical or urodynamic data. Methods During a 1-year period, every man 45 years or older with lower urinary tract symptoms suggestive of benign prostatic hyperplasia was systematically evaluated with multi-channel computer-urodynamic investigation and IVU. Men with urinary retention, known bladder stones or diverticula, severely impaired renal function, or allergy to iodine contrast media were excluded. Structural alterations of the urinary tract were correlated with clinical and uro- dynamic data using logistic regression analysis. Results Data on 203 consecutive patients were available for analysis. Multivariate analysis demonstrated that the ‘‘ﬁsh-hook’’ conﬁguration of the distal ureter (also known as ‘‘hockey-stick’’, or ‘‘J-shaped’’ ureter) was the only sign signiﬁcantly associated with benign prostatic obstruction (BPO) (odds-ratio 3.64; 95% conﬁdence interval 1.69–7.83; P \ 0.001). The sensitivity, speciﬁcity, positive and negative predictive values of the ‘‘ﬁsh-hook’’ ureter C. Mamoulakis Department of Urology, University of Crete Medical School, Heraklion, Crete, Greece T. R. W. Herrmann K. Ho¨fner M. Oelke (&) Department of Urology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany e-mail: oelke.matthias@mh-hannover.de K. Ho¨fner Department of Urology, Evangelic Hospital, Oberhausen, Germany conﬁguration sign to detect BPO was 53, 76, 61 and 70%, respectively. Bladder trabeculation, upper urinary tract dilatation, or bladder base elevation were not associated with BPO, detrusor overactivity, detrusor underactivity, bladder low-compliance or any clinical data. Conclusions The ‘‘ﬁsh-hook’’ shape of the distal ureter(s) indicates BPO and may be a result of prostate median lobe enlargement. Keywords Benign prostatic hyperplasia Bladder outlet obstruction Fish-hook ureter Intravenous urography Lower urinary tract symptoms Sensitivity Speciﬁcity Urodynamic investigation Abbreviations BPH Benign prostatic hyperplasia BPO Benign prostatic obstruction BPE Benign prostatic enlargement CI Conﬁdence interval IPP Intravesical prostatic protrusion IPSS International prostate symptom score IVU Intravenous urography LUTS Lower urinary tract symptoms OR Odds ratio PVR Post-void residual urine TRUS Transrectal ultrasound UDI Urodynamic investigation Introduction Benign prostatic hyperplasia (BPH) is the term used to describe the growth of epithelial, muscular and/or ﬁbrotic 123