The effect of vaginal delivery and Caesarean section on the anal Sphincter complex of Primipara based on optimized three-dimensional ultrasound image and nuclear regression Reconstruction Algorithm

Objective: The study used the optimized nuclear regression reconstruction algorithm to explore the value of three-dimensional perineal ultrasound evaluation of the effect of caesarean delivery and caesarean section on the anal sphincter complex of primipara.

Methods: This study performed three-dimensional perineal ultrasound scanning of the anal sphincter complex of 157 primiparas 42 days after delivery. Among them, 77 were in caesarean delivery (spontaneous delivery group) and 80 were in caesarean section (caesarean delivery group) from September 2018 to December 2020 in our hospital. The thickness of the end plane, the middle plane, the distal plane and the distal plane of the external anal sphincter at 3, 6, 9, 12 o’clock direction, and measure the thickness of the central plane of the pubic rectum muscle at 4, 8 o’clock direction. At the same time, the study used tomography and volume contrast imaging to observe the morphology and integrity of the anal sphincter complex.

Results: The thickness of the distal anal sphincter at the 12 o’clock direction, the proximal anal sphincter at 6, 12 o’clock, and the central plane at 9 and 12 o’clock in the obstetric group were smaller than those in the caesarean section group (all P < 0.05). There were no significant differences in the thickness of the remaining anal internal and external anal sphincter and puborectalis muscles between the two groups in different directions (all P>0.05). In the obstetric group, a perineal sphincter defect was found via three-dimensional perineal ultrasound.

Conclusion: The delivery method has a certain influence on the shape of the anal sphincter complex. The thickness of the internal and external anal sphincter of the primiparous women in a certain direction is significantly smaller than that of caesarean section. Transperineally three-dimensional ultrasound can clearly show the morphological characteristics and integrity of the anal sphincter complex, and diagnose the defect of the anal sphincter complex.