Transobturator tape: variation in the vascular anatomy of the obturator foramen
Ottem Derek, Stothers Lynn, ;
University of British Columbia, Vancouver, British Columbia, Canada
Oct 2007 (Vol. 14, Issue 5, Pages( 3678 - 3683)
AIMS: 1) To describe the anatomy of the obturator canal and variations in placement of the obturator nerve, artery and vein and 2) To record the proximity of these structures to the optimal point of placement of the transobturator tape (TOT) trochar. METHODS: Eighteen obturator foramens were dissected in nine female cadavers. The obturator nerve, artery and vein were exposed as they entered the foramen. Orientation of the obturator nerve, artery and vein from medial to lateral were recorded. Obturator arterial and venous branches > 1 mm crossing the obturator membrane were noted. Usual placement of the TOT trochar as it passes through the obturator membrane to the obturator canal was determined and the distance from the trochar to each of the structures was recorded.
The medial to lateral orientations of the obturator nerve, artery and vein are variable where these structures enter the obturator canal. The vein appeared most medially in 78% of cadavers and the artery in 22%. The nerve was located most lateral in all cases. Venous (22%) and arterial (17%) branches of the obturator vessels traversed medially across the obturator membrane towards the side of trochar placement. The mean distance from optimal trochar placement to the obturator canal was 30 mm.
The anatomy of the obturator foramen is not consistent. The proximity of the obturator canal to the TOT trochar, the medially crossing obturator nerve, artery and vein and their branches, as well as their variable orientation in the canal should be considered when performing the transobturator tape procedure.