Uretroplastica ricostruttiva con matrice acellulare suina (SIS) : evoluzione della tecnica di impianto e risultati di 10 anni di esperienza

Long tract urethral reconstruction still has no other resolution than two-stage techniques or graft and flap procedures, that are neither simple nor trouble-free. Tissue engineering simplifies this surgery using porcine acellular matrix, obtained from small intestine submucosa (SIS): thin but strong, ready for grafting, it is not immunogenic, being deprived of cells. It is a biological bridge for reconstruction, promoting the regeneration of surrounding tissue. We report our experience using SIS for urethroplasty. After coronal or perineal-scrotal incision and penile degloving, the urethra is rotated of 180° and opened through the entire restricted tract. The graft is sutured dorsally and reinforced by the contact with the cavernous bodies to prevent pouching. From 1999 to 2005 we performed this grafting procedure in 36 men and 4 women. Afterwards, 16 more surgeries performed were with direct ventral graft procedure, without urethra isolation and rotation, with worthy simplification. A 10-year follow-up shows satisfactory urodynamic and subjective outcomes for both procedures, assessed by voiding urethrography, uroflowmetry, International Prostate Symptom Score, and Quality of Life perception. At urethroscopy the graft appears completely homogeneous to the native tissue, as confirmed by the histological examination. The ventral direct graft represents the more consistent innovation: we did not observe pouching and the results remained effective. For penile urethra, in a few patients, periodic dilatations were necessary. SIS can be considered as an alternative to more difficult grafting procedures, which are probably no more indispensable in urethral enlargement, even for critical strictures