Simple Anal Fistula: Clinical Criteria for Diagnosis and Local Anesthesia with Conscious Sedation for Surgery -an Observational Study

Abstract

ABSTRACT PURPOSE: To evaluate (i) acceptability of surgery for simple anal fistula under local anesthesia with conscious sedation by the patients and (ii) accuracy of a set of clinical criteria for diagnosis of simple anal fistula. METHODS: A set of clinical criteria based on physical findings was used to diagnose patients with simple anal fistula. These patients were operated under local anesthesia with conscious sedation. Intravenous paracetamol, diclofenac sodium, and midazolam were administered as adjuvants. Fistulotomy with/without marsupialisation was performed in most patients. Clinical diagnosis was matched with operative findings. RESULTS: Among 193 patients presenting with anal fistula, 61 patients were diagnosed as simple anal fistula and were scheduled for surgery under local anesthesia with conscious sedation. One patient was found to have complex anal fistula during intraoperative assessment and surgery was deferred. Surgery could be completed under local anesthesia with conscious sedation for 58/60 (96.7%) patients. Acceptability of the procedure was assessed with two parameters: the patients’ satisfaction score on visual analogue scale and their willingness to undergo fistula surgery under local anesthesia again, if required. Median (interquartile range) visual analogue scale score for patients’ satisfaction was 10 (9-10). All the patients expressed their willingness to undergo fistula surgery under local anesthesia again, if required. The clinical criteria was successful in diagnosing simple anal fistula in 58/61 (95.1%) patients. The remaining three patients had high intersphincteric fistula (1) and blind sinus (2). CONCLUSIONS: Acceptability of surgery for simple anal fistula under local anesthesia with conscious sedation was excellent. The proposed clinical criteria were highly accurate in diagnosing simple anal fistula.

Keywords

• fistula in ano
• intersphincteric anal fistula
• transsphinteric anal fistula
• complex anal fistula
• magnetic resonance scan
• operative surgery