Are there differences in the damage to the pelvic floor between malmstrom's and kiwi omnicup vacuums? A multicenter study

OBJECTIVES: The objective of this study is to investigate a multicenter study to establish if differences exist in the levator ani muscle avulsion (LAM) rates between deliveries performed with Malmstrom's vacuum and the Kiwi vacuum. STUDY DESIGN: A prospective, multicenter observational study with 199 primiparous subjects was performed. All patients had undergone vaginal delivery by vacuum (Malmstrom's or Kiwi). Avulsion was defined as an abnormal insertion of LAM in the lower pubic branch in the multiplanar mode, as identified in the three central sections by transperineal 3/4D echography 6 months after delivery. The area of the levator hiatus was measured in the plane of minimum dimensions at rest, during the Valsalva maneuver and during contraction. RESULTS: LAM avulsion occurred in 33.1% of cases in which Malmstrom's vacuum was used and in 29.4% of cases in which the Kiwi vacuum was used (the difference was not statistically significant), which resulted in a crude odds ratio (OR) of 0.977 (0.426, 2.241; P = .957) and an adjusted OR of 2.90 (0.691; 12.20; P = .146). Women in the Malmstrom's vacuum group had a larger LHA at rest 14.77 vs 12.64 cm(2) ; P = .001) and at maximum contraction (13.41 vs 10.83 cm(2) ; P < 0.001) in comparison with the Kiwi group, although the difference did not reach statistical significance under Valsalva maneuver (18.71 vs 17.21 cm(2) ; P = .051).Differences between both groups were detected in the measurements of the hiatus area levator at rest (14.77 vs 12.64 cm(2) ), during the Valsalva maneuver (18.71 vs 17.21 cm(2) ) and during maximum contraction (13.41 vs 10.83 cm(2) ). CONCLUSIONS: In the present study, Malmstrom's vacuum was not associated with a higher risk of LAM in comparison with Kiwi's Omnicup.