Anatomic comparison of two transobturator tape procedures.

OBJECTIVE

Both outside-in and inside-out methods are available for transobturator tape placement. Our objective was to compare these methods regarding proximity of the tape to the obturator canal and ischiopubic ramus.

METHODS

Using seven fresh frozen cadavers, transobturator tapes were placed using the inside-out (TVT-Obturator System, Gynecare, Ethicon Inc, Somerville, NJ) and outside-in (Monarc, American Medical Systems, Minnetonka, MN) methods bilaterally in each cadaver. We dissected to the level of the obturator membrane and measured the distance from the closest aspect of the obturator canal and ischiopubic ramus to each tape.

RESULTS

Transobturator tapes placed by using the inside-out technique were significantly closer to the obturator canal than with the outside-in method (mean distances: 1.3+/-0.44 cm compared with 2.3+/-0.41 cm, respectively, P<.001); the greater proximity of the inside-out method was noted in all dissections. Tapes placed with the inside-out method were also farther from the ischiopubic ramus than those placed with the outside-in approach (mean distances: 0.39+/-0.44 cm compared with 0.04+/-0.13 cm, respectively, P=.008). When distances between the tapes relative to the obturator canal were further analyzed according to left or right side, the difference between methods was maintained. Additionally, the distances were consistently farther from the obturator canal on the left side than on the right side regardless of transobturator tape approach.

CONCLUSION

The outside-in technique results in the mesh being placed farther from the obturator canal and closer to the ischiopubic ramus, theoretically reducing the risk of neurovascular injury.

LEVEL OF EVIDENCE

II.