Objective: To evaluate the effects of two kinds of individual extralevator abdominalperineal excision(ELAPE) on female pelvic floor biomechanics.
Methods: Four kinds of finite element model were developed: intact models, ELAPE models and two kinds of individual ELAPE models. The maximal stress and stress distributions of each model under the same pressure were analyzed and compared.
Results: In the individual ELAPE models of dissection plane close to rectum on one side, non-levator ani tissue's maximal stress on levator ani partly reserved side and totally removed side were (3.114±0.129) and (4.856 ±0.128) MPa. The former were lower than the latter (P<0.01). They were both lower than those in ELAPE models which were (5.127±0.070) MPa (P<0.01), and were higher than those in intact model which were (1.963±0.061) MPa (P<0.01). In the individual ELAPE models of dissection plane close to pelvic on one side, non-levator ani tissue's maximal stress on both sides, which were (5.131±0.067) MPa, were similar to those in ELAPE models (P>0.05).
Conclusion: ELAPE of dissection plane close to rectum on one side is able to reduce the stress of non-levator ani tissue on both sides, especially on levator ani partly reserved side; conversely, ELAPE of dissection plane close to pelvic on one side may not reduce the stress of non-levator ani tissue on either side.