Short and long term results of anatomical reconstruction of perineal body and sphincter complex in obstetric anal sphincter injuries.

Objectives: The effective way to reduce the risk of fecal incontinence (FI) in primary repaired obstetric anal sphincter injuries (OASIS) patients is to accurately detect the injury and provide complete anatomical reconstruction. The aim of the study was to evaluate the short-term and long-term results of OASIS cases that were diagnosed by an experienced surgical team and whose perineal body and anal sphincters were reconstructed separately.

Material and methods: Sixteen patients that required consultations due to anal sphincter damage during vaginal delivery and underwent anatomical reconstruction due to Grade 3c and Grade 4 sphincter damage between 2007 and 2019 were included in the study. These cases were divided into three groups [Group 1 (≤12 months), Group 2 (12-60 months), Group 3 (≥60 months)] according to the time elapsed until anal manometry, and incontinence questionnaires were conducted in the postoperative period. Recto-anal inhibitory reflex (RAIR), mean resting (IB) and squeezing (SB) pressures were measured by anal manometry. Anal incontinence (AI) and FI rates were determined by questionnaires. Anal sphincter damage repair techniques (overlapping, end-to-end) were determined. These parameters were compared between the three groups.

Results: Mean age of the patients was 27.5 (16-35) years. Six (37.5%) patients had Grade 3c, while 10 (62.5%) had Grade 4 injury. The overall mean RP and SP were 35 (26-56) mmHg and 67 (31-100) mmHg, respectively. Mean RP and SP were 46/67 mmHg, 33.5/75.5 mmHg, and 37.5/70.5 mmHg in Groups 1, 2, and 3 respectively. There was no difference between the three groups in terms of mean RP and SP (p= 0.691, p= 0.673). The rate of AI and FI in all patients were 18.75% and 12.5%, respectively while the rate of severe AI incontinence was 6%. Severe AI was observed in 1 (16.7%) case in Group 1, mild AI was observed in 1 (25%) case in group 2, and in 1 (16.7%) case in Group 3. RAIR was positive in all patients. In Group 1, 5 (83.3%) patients underwent overlapping repair, and in Group 3, 6 (100%) patients underwent end-to-end repair. This difference was statistically significant (p= 0.011).

Conclusion: In vaginal births, evaluation of anal sphincter damage, determination of perineal body structures and anal sphincters separately and performing anatomical reconstruction when needed significantly reduce the rate of FI in the short and long term.