Study On The Characteristics And Recurrence Factors Of Recurrent Anal Fistula Based On Magnetic Resonance Imaging

Objective: In this study,magnetic resonance imaging was used to analyze the fistula characteristics of recurrent anal fistula and the related risk factors of anal fistula recurrence,so as to provide reference for clinical treatment and prevention of anal fistula recurrence.Methods: The clinical data and nuclear magnetic resonance data of 126 patients with anal fistula who underwent surgical treatment in the First Affiliated Hospital of Guangxi University of Traditional Chinese Medicine from January 2019 to March 2022 were mainly collected.The anal fistula type,internal orifice position,internal orifice number,fistula number,muscle through the fistula,the gap through the fistula and related recurrence risk factors of recurrent anal fistula and primary anal fistula were compared and analyzed by magnetic resonance.Results: Analysis of general characteristics,the body mass index(BMI)of the primary anal fistula group was 24.41 ± 4.63 kg / m2,and the recurrent anal fistula group was 25.80 ± 4.57 kg / m2,the difference was statistically significant(p < 0.05).There was no significant difference in gender,age and diabetes history.Analysis of fistula characteristics: 1.Recurrent anal fistula was mainly of sphincter type(57.1%);The position of the inner mouth is mainly located in the posterior position(42.9%);The relationship between the inner mouth and the tooth line is mainly located at the tooth line(65.7%).2.Recurrent anal fistulas mainly passed through the sphincter space(40.0%)and the ischiorectal space(28.6%),and some of them invaded the superior space of the levator ani(8.6%).Primary anal fistulas mainly passed through the sphincter space(58.2%).3.Recurrent anal fistula mainly involved the deep part of the external sphincter(37.1%)and the superficial part of the external sphincter(31.4%),and primary fistula mainly involved the lower part of the skin of the external sphincter(48.4%).4.The average number of internal openings in recurrent anal fistula was 1.46 ± 0.69,and the average number of internal openings in primary anal fistula was 1.15 ± 0.44,with a statistically significant difference(p<0.05).5.The average number of fistulas in recurrent anal fistula was 1.50 ± 0.55,and the average number of fistulas in primary anal fistula was 1.14 ± 0.38,with a statistically significant difference(p<0.05).6.In recurrent anal fistula,complex anal fistula accounts for 60%,while in primary anal fistula,complex anal fistula accounts for 17.6%,with a statistically significant difference(p<0.05);7.74.3% of recurrent anal fistulas were accompanied by abscesses,while 39.6% of primary anal fistulas were accompanied by abscesses,with a statistically significant difference(p<0.05).Binary logistic multivariate analysis showed that the number of fistulas(p < 0.05),perianal abscess(p < 0.05),and the number of internal orifices(p < 0.05)were independent risk factors for anal fistula recurrence.The more the number of fistulas in patients with anal fistula,the higher the risk of recurrence(OR = 10.107,95 % CI 2.158-47.340).The more the number of internal openings in patients with anal fistula,the higher the risk of recurrence(OR = 1.409,95 % CI 0.033-5.115).Patients with anal fistula complicated with abscess had a higher risk of recurrence than those without abscess(OR= 8.541,95 % CI 1.698-42.964).Conclusion(s): Recurrent anal fistula has the characteristics of a large number of fistulas,a large number of internal openings,and a high invasion location;The number of fistulas,the presence of perianal abscesses,and the number of internal openings in patients with anal leakage are independent risk factors affecting the recurrence of anal leakage;Magnetic resonance imaging plays an important role in evaluating the course of recurrent anal fistula,as well as the relationship between fistula and perianal muscles and spaces.