the urinary meatus as glanular, coronal, shaft, or proximal to shaft. Maternal and fetal risk factors for hypospadias severity were compared using logistic regression. RESULTS The total number of male pregnancy and birth records during the study period was 130,796. The total number of cases of hypospadias was 995, yielding an incidence of 0. 76%. The severity of hypospadias was graded as glanular in 428 (77.8%); coronal in 77 (14%); penile shaft in 34 (6.2%); and proximal to the penile shaft in 12 (2.2%). The severity of hypospadias was not graded in 445 cases. Low birth weight, low gestational age, and maternal age were associated with increased severity of hypospadias. Only maternal age was associated with an increased severity of hypospadias when logistic regression was performed. Some limitations of our study included self- reporting for some parameters such as smoking and lack of data for some potentially important factors such as the use of assisted reproductive technologies. CONCLUSIONS Advanced maternal age was associated with increased severity of hypospadias in our population (p < 0.03). # S07-2 (PP) RABBIT URETHRA REPLACEMENT WITH A MOLECULARLY-DEFINED TUBULAR TYPE I COLLAGEN BIOMATRIX Jody NUININGA 1 , Martin KOENS 2 , Dorien TIEMESSEN 3 , Paul GEUTJES 3 , Marco BOL 4 , Willeke DAAMEN 2 , Egbert OOSTERWIJK 3 , Toin VAN KUPPEVELT 1 , Jack SCHALKEN 3 and Wout FEITZ 1 1 Radboud University Nijmegen Medical Center, Urology, Nijmegen, NETHERLANDS, 2 Radboud University Nijmegen Medical Center, Biochemistry, Nijmegen, NETHERLANDS, 3 Radboud University Nijmegen Medical Center, Experimental Urology, Nijmegen, NETHERLANDS, 4 Radboud University Nijmegen Medical Center, Pathology, Nijmegen, NETHERLANDS PURPOSE The evaluation of a tubular molecularly- defined type I collagen biomatrix for replacement of the urethra in a rabbit model as a preclinical model. MATERIAL AND METHODS Highly purified type I collagen was obtained according to protocol. Tubular collagen biomatrices (Ø 3 mm) were prepared by lyophilization and strengthened by chemical crosslinking. Sixteen rabbits underwent tubular urethral replacement (resection of 1.0 cm segment of the urethra) which was replaced with the tubular biomatrix. The grafts of regenerated urethras were harvested at 2 weeks, 1, 3 and 6 months after surgery. Retrograde urethrography was performed in all rabbits before sacrifice. Then, the total penis of the rabbit was excised for histopathological examination. RESULTS Biomatrices were biochemically analyzed and crosslinking was successful. No animals died before sacrifice. No strictures or urethrocutaneous fistula were observed on control urethrography. All animals showed no stenosis or loss of calibre at the biomatrix’s position. There was relative anastomotic narrowing of the urethra in one rabbit at 2 weeks. Two rabbits had small diverticula at 3 months. Macroscopically, no infectious tissue was harvested. Currently, histological analysis is ongoing. CONCLUSIONS The tubular molecularly-defined biomatrices are successful in repairing urethral lesions. The results with our tubular biochemically defined biomatrix are promising, but remain to be confirmed by histological evaluation. Futurewise, the use of longer tubular segments and the addition of growth factors to biomatrices may be investigated. # S07-3 (O) LONG-TERM FOLLOW-UP AFTER HYPOSPADIAS REPAIR WITH CULTURED AUTOLOGOUS CELLS Magdalena FOSSUM and Agneta NORDENSKJO ¨ LD Karolinska Institutet, Pediatric Surgery, Stockholm, SWEDEN PURPOSE During 2000- 2002 we reconstructed the urethra in six boys with severe hypospadias with cultured autologous urothelial cells. The aim of this study was to evaluate the long-term effects of the treatment. MATERIAL AND METHODS Patients with severe hypospadias were subjected for a two-staged repair. Urothelial cells were isolated through bladder washing at the first surgical procedure for in vitro culturing and expansion. A transplant of urothelial cells on a collagen matrix was used in an on-lay fashion to create the neourethra at the second operation. The outcome was evaluated in respect to cosmetic appearance, voiding, urinary flow, erection, cystoscopy and biopsies. RESULTS Median follow-up time is 7,25 years (range: 6 to 8,6 years). Up to date, all patients present with good cosmetic appearance with a coronar meatus. One of the boys prefer a sitting voiding position (low positioned, small penile body as part of PAIS). Urinary flow curves are bell-shaped in all but one. All have straight erections, cystoscopy reveal an even, non-hair bearing surface on the transplanted side and 2/6 present with urothelial cells in biopsies, subepithelial architecture is normal in all. CONCLUSIONS Tissue engingeering for severe hypospadias repair can be performed in a safe manner. This presentation is a conclusion ESPU Programme 2009 S55