Clinical Outcomes of Medical Management Options for Chronic Anal Fissures in a Long-Term Follow-up: Systematic Review and Meta-Analysis.

[BACKGROUND] Topical treatments and botulinum toxin injections are valid options for the management of patients with chronic anal fissures (CAF), but little is known about the efficacy of these techniques in long-term follow-up. The aim of this meta-analysis was to evaluate the effectiveness, given to clinical outcomes, of medical treatments with calcium antagonists, nitroglycerin, and botulinum toxin on CAF treatment in adults.

[METHOD] A systemic review and meta-analysis developed according to PRISMA [PLoS Med. 2009 Jul 21;6(7):e1000100; BMJ. 2010 Mar 23;340:c332] and registered in PROSPERO (Registration number: CRD42020120386). A systematic literature search was conducted through MEDLINE, EMBASE, Web of Science, and Cochrane Library databases. Randomized control trials that compared medical treatment were identified; publications had to have a clinical definition of CAF with at least one of the following signs or symptoms: visible sphincter fibers at the base of the fissure, anal papillae, sentinel piles, and indurated margins. The symptoms had to be chronic for at least 4 weeks. Data were independently extracted for each study, and a meta-analysis was drawn using fixed- and random-effects models.

[RESULTS] 17 randomized trials met the inclusion criteria. Diltiazem showed a superior effect compared with glycerin (RR = 1.16 [95% CI = 1.05-1.30]; I2 = 18%) and with fewer adverse effects (RR = 0.13 [95% CI = 0.04-0.042]; I2 = 87%). Similar results were evidenced with the use of nifedipine compared with lidocaine (RR = 4.53 [95% CI = 2.99-6.86]; I2 = 28%). Botulinum toxin did not show statistically significant differences compared to glycerin (RR = 0.81 [95% CI = 0.02-29.36]; I2 = 93%) or isosorbide dinitrate (RR = 1.45 [95% CI = 0.32-6.54]; I2 = 85%). Regarding recurrence, nifedipine was superior to lidocaine (RR = 0.18 [95% CI = 0.08-0.44]; I2 = 31%).

[CONCLUSIONS] Calcium channel blockers performed well regarding the healing of CAF when compared to others in long-term follow-up. The superiority of botulinum toxin was not evidenced compared to topical treatments. More studies are needed to better assess recurrence rates.