Non-Locatable Internal Opening in Anal Fistula Associated with Acute Abscess and Its Definitive Management by Garg Protocol

BACKGROUND: Definitive management of acute fistula-abscess (anal fistulas associated with acute abscess) is gaining popularity against the two-staged approach (early abscess drainage with deferred fistula management). However, locating an internal opening (IO) in acute fistula-abscess can be difficult. A recent protocol (Garg protocol) has been shown to be effective in managing anal fistulas with non-locatable IO. PURPOSE: To test the efficacy of the Garg protocol in managing acute fistula-abscess with non-locatable IO. METHODS: Patients with acute fistula-abscess operated by a definitive procedure were included. A preoperative MRI was done in all patients. Patients in whom the IO was non-locatable after clinical, MRI, and intraoperative examination were managed by the three-step Garg protocol. Garg protocol: 1) Reassessment of MRI; 2) In non-horseshoe fistulas, the IO was assumed to be at the point where the fistula tract reached closest to the sphincter-complex; 3) In horseshoe fistulas, the IO was assumed to be located in the midline (anterior or posterior as per the horseshoe location). Low fistulas were treated by fistulotomy and high fistulas by a sphincter-sparing procedure. The long-term healing rate and change in continence (Vaizey scores) were evaluated. RESULTS: A total of 201 patients with acute fistula-abscess were operated over six years, and 19 were lost to follow-up. A total of 182 patients (154-males) were followed up (median-37 months). The IO was locatable in 133/182 (73.1%) (control group) and was non-locatable in 49/182 (26.9%) (study group). The study group was managed as per the Garg protocol. The age, sex-ratio, and fistula parameters were comparable in both groups. The long-term healing rate was 112/133(84.2%) in the IO-locatable group and 43/49 (87.8%) in the IO-non-locatable group (p=0.64, not-significant). The objective continence scores did not change significantly after surgery in both groups. CONCLUSION: Acute fistula-abscess with non-locatable IO can be managed successfully by the Garg protocol without any risk of incontinence.