Transobturator Vaginal Tape Inside Out for Treatment of Urethral Sphincter Mechanism Incompetence in Female Dogs: Cadaveric Study and Preliminary Study in Continent Female Dogs

ABSTRACT
Objectives – 1) To describe a surgical technique adapted from the “transobturator vaginal tape inside-out” (TVT-O) used in women and to define the trajectory of the tape on cadavers, and 2) To determine the urodynamic and morphological effects of the TVT-O in continent bitches.
Study Design – Cadaveric and experimental in vivo study.
Animals – Fresh female canine cadavers (n = 12) and spayed female Beagle dogs (n = 2).
Methods – 1) TVT-O was inserted in 12 cadavers. Dissection was performed and distances between the tape and neighboring structures were recorded. 2) TVT-O was inserted in 2 continent female Beagle dogs. Urethral pressure profilometry (UPP) and vaginourethrograms were performed preoperatively, immediately after surgery and 2, 4, and 6 months postoperatively. Histopathology was performed 6 months after surgery.
Results – 1) TVT-O tape was consistently located in a perineal space before entering the obturator foramina and was located at a safe distance from major neurovascular structures including the femoral vessels and the obturator nerve. 2) UPP showed an increased integrated pressure postoperatively up to 4 postoperative months. Vaginourethrograms performed postoperatively showed a ventral displacement and narrowing of the distal urethra. Histopathological examination of the tissues surrounding the tape revealed a mild fibroblastic proliferation with a mild to minimal lympho-plasmocytic inflammatory infiltration.
Conclusions - TVT-O is a feasible and accurate procedure which can be performed in continent bitches with a low risk of complications.