A biomechanical, histological and biochemical study in an experimental rabbit hypospadias repair model using scanning acoustic microscopy

Lalla, Marianna; Riis, Carsten; Jørgensen, Claus Schiøtt; Danielsen, Carl Christian; Jørgensen, Troels Munch

doi:10.1016/j.jpurol.2010.07.011

« Previous Next »Journal of Pediatric Urology
Volume 7, Issue 4 , Pages 404-411, August 2011

A biomechanical, histological and biochemical study in an experimental rabbit hypospadias repair model using scanning acoustic microscopy

Marianna Lalla
- Institute of Clinical Medicine, Aarhus University Hospital Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N, Denmark
- Department of Paediatric Urology, Afdeling K, Aarhus University Hospital Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N, Denmark
- Corresponding author. Department of Paediatric Urology, Afdeling K, Aarhus University Hospital Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N, Denmark. Tel.: +45 8949 5926; fax: +45 8949 6006.
- Present address: Great Ormond Street Hospital, Great Ormond Street, Urology Office, 7th floor Southward Building, London WC1N 3JH United Kingdom. Tel.: +44 0 2074059200x0203; fax: +44 0 2078138260.
Carsten Riis
- Institute of Clinical Medicine, Aarhus University Hospital Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N, Denmark
Claus Schiøtt Jørgensen
- Institute of Clinical Medicine, Aarhus University Hospital Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N, Denmark
Carl Christian Danielsen
- Department of Connective Tissue Biology, Institute of Anatomy, University of Aarhus, building 1233, Wilhelm Meyers Allé 3, 8000 Aarhus C, Denmark
Troels Munch Jørgensen
- Institute of Clinical Medicine, Aarhus University Hospital Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N, Denmark
- Department of Paediatric Urology, Afdeling K, Aarhus University Hospital Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N, Denmark

Received 13 December 2009; accepted 23 July 2010. published online 19 August 2010.

Abstract

Objective

To investigate the biomechanical, histological and biochemical properties of rabbit urethra at long-term follow up after hypospadias simulation and acute repair.

Materials and methods

Thirty-eight white New Zealand male rabbits underwent experimental creation of a hypospadias-like defect and acute repair (mobilization and advancement, tubularized incised posterior urethral plate (TIP), modified TIP) and sham operation. After 23 weeks all groups + controls underwent biomechanical, histological and biochemical assessments.

Results

The mobilization and advancement group showed a higher stiffness compared to the TIP groups (P < 0.05) in the posterior urethra, whereas the TIP group was stiffer compared to the other two operative groups (P < 0.001) in the ventral urethra. In the dorsal urethra, the mobilization and advancement group and the modified TIP group had a higher collagen content compared to shams (P < 0.05). No differences in collagen content were found between groups in the ventral urethra. A correlation between acoustic and histological layers was found, partially related to collagen content.

Conclusion

The urethras had different microelastic properties in different layers of the dorsal and ventral urethra, with higher stiffness in the connective tissue layers surrounding and within the urethra. The repaired urethras had partially recovered their elasticity at micrometer resolution at long-term follow up. Scanning acoustic microscopy elucidated structure–function relationships at microscopic level in normal and operated urethra.

Keywords: Biomechanics, Acoustic microscopy, Urethra, Rabbit, Hypospadias