This study involves 110 female patients, all affected by idiopathic and non-recurrent CAF who underwent surgical procedure, from January 2010 to January 2019. Exclusion criteria for the study were: the presence of multiple fissures, fistulas in ano, syphilis, inflammatory bowel disease, anal abscess, malignant disease and previous anorectal surgery. All patients were followed up for at least 2 years after the surgical procedure. The patients’ outcome data were retrieved from a prospectively monitored database.
We conduct this study in compliance with the principles of declaration of Helsinki, the protocol for this study has been submitted to the Ethical Committee of our institution, which did not consider necessary to approve it. Written informed consent was obtained from all the study participants.
Preoperative manometric evaluation was performed after a reasonable period of suspension of all medical therapy influencing IAS tone. The manometric evaluation was carried out by a manometric sensor using the station pull-through as described in our previous work . A manometric evaluation has been undertaken at 12 and 24 months after surgery.
Data collected on healthy subjects by our anorectal pathophysiological laboratory showed that normal values of maximum resting pressure (MRP) and maximum squeeze pressure (MSP) were respectively 68,1±12,3 mmHg and 112 ± 36,2 mmHg . The normal range of MRP, according to Jones et al. , were 45-85 mmHg; so that CAAF without hypertonic IAS were defined as those with MRP values < 85mmHg.
All patients underwent fissurectomy and anoplasty with V-Y skin flap advancement lying in a gynecological position under spinal or general anesthesia.
The sentinel skin tags and hypertrophied anal papilla located at the dentate line were excised, if present; the tissue at the base of the fissure was curetted until clean IAS muscle fibers were reached. Technical details concerning the surgical procedure have already been widely explained in a previous work from our group .
The patients with hypertonic IAS were treated with intraoperative local injection of 30 U.I. of botulinum toxin A (Botox, Allergan Westport, Ireland)  or with local administration of post-operative nifedipine and lidocaine for 15 days after surgery (Antrolin ®) . Before surgery, all patients received a small volume of phosphate-saline enema. Metronidazole was administered intravenously in a dose of 500mg 1h before surgery, subsequently, it was administered per os at the dosage of 250 mg for 7 days, three times daily. During the first two weeks after the surgery, patients took variable doses of psyllium fibers. A laxative preparation (sennosides) was given orally to subjects who had not yet passed stools 3 days after surgery. Immediately after surgery, all patients received 100 mg of diclofenac intramuscularly for analgesia and were instructed to take only 100mg of nimesulide tablets as requires.
A complete healing was defined as a complete epithelialization of the advancement skin flap. Recurrent CAFs were defined as those who occurred after the complete healing of the previous wound. Both duration and intensity of post-defecatory pain have been evaluated; the intensity was evaluated with a visual analogue scale (VAS).
FI was assessed preoperatively and 6,12 and 24 months after surgery according to Pescatori’s grading system : A incontinence for flatus and mucus; B for liquid stool; C for solid stool; 1 for occasional; 2 for weekly and 3 for daily. Patients were discharged within 24 hours after surgery, afterwards they were examined until they were completely healed and they were also followed up until 24 months following the surgical procedure. Independently of the scheduled appointments, patients have been seen on request.