Early outcomes of chronic anal fissure treatment using the lateral internal sphincterotomy method without excision (randomized trial NCT05117697)

PURPOSE OF THE STUDY: improvement of the treatment of chronic anal fissure results.PATIENTS AND METHODS: the study included 70 patients randomized by random number generation into 2 groups: 30 patients underwent lateral internal sphincterotomy (main group, LIS), and 40 patients underwent LIS in combination with the excision of the fissure (EF) (control group, LIS + EF).RESULTS: the pain intensity both after stool and during the daytime in the main group (LIS) has been significantly lower than in the control group (LIS + EF) (p < 0.05). The median duration of the patients’ temporary disability in the LIS group was 6 (4; 9) days, in the LIS + EF group — 17 (9; 23.5) days (p = 0.04). On day 15, the defect has epithelialized in 12/30 (40%) patients of the main group (LIS) and none (0/40) in the control group (LIS + EF) (p = 0.00001), on day 30 — in 22/30 (73.3%) and 2/40 (5%) (p = 0.00001), on day 45 — in 26/30 (87%) and 20/40 (50%) (p = 0.002), and on day 60 — in 28/30 (93.3%) and 38/40 (95%) (p = 1.0), respectively. On the day 30 after surgery, 3/30 (10%) patients of the main group and 15/40 (37.5%) of the control group had complaints regarding passing gas (p = 0.01), on day 60 — anal sphincter insufficiency (ASI) persisted in 1/30 (3%) patients in the LIS group and in 3/40 (7.5%) patients in the LIS + EF group (p = 0.63). Excision of the fissure in 5.4 (1.4–20.9) times increases the chance of developing ASI on day 30 of the postoperative period (p = 0.015) and 52 (10.2; 268.3) times increases the chance of non-healing of the defect during this period (p = 0.000002) and 6.5 (1.9; 22) times on the day 45 (p = 0.003), in comparison with the LIS only.CONCLUSION: refusal to excise the anal fissure during its surgical treatment and perform the lateral internal sphincterotomy only can reduce the intensity of postoperative pain syndrome, the rate of postoperative complications and reduce the time of epithelialization of the anoderm defect.