Predictors of Outcome for Anal Fistula Surgery

Abstract

Setting: A regional tertiary referral center.Patients: Adult patients with anal fistula secondary to cryptoglandular disease.Interventions: Fistulotomy, advancement flap, and fistula plugging.Main Outcome Measures: Rates of operative failure (persistent fistula), incontinence, and septic complications. We evaluated age, sex, previous operation, fistula type, number of fistula tracts, horseshoe fistula, and intervention type to determine their independent influence on outcomes.Results: One hundred seventy-nine patients (79.3% male) underwent fistula operation from October 1, 2003, through December 31, 2008. Median age was 45 years. Fistulotomy was undertaken in 82.7% of patients, ad-vancement flap in 10.6%, and plugging in 6.7%. The rates of operative failure, postoperative incontinence, and septic complications were 15.6%, 15.6%, and 7.3%, respectively. Plugging carried the highest failure rate (83.3%) compared with fistulotomy (10.1%) (odds ratio [OR], 44.3 [95% confidence interval (CI), 8.9-221.0; PϽ.001]) and was the only independent predictor for failure after adjusting for all variables. Being older than 45 years was associated with a higher postoperative incontinence rate compared with the younger group (adjusted OR, 2.8 [95% CI, 1.0-7.7; P=.04]). High transsphincteric and suprasphincteric fistulas were predictors of incontinence compared with subcutaneous fistulas (adjusted OR, 22.9 [95% CI, 2.2-242.0; P=.009] and 61.5 [4.5-844.0; P=.002], respectively). The only predictor of septic complications was plugging compared with fistulotomy (adjusted OR, 15.1 [95% CI, 2.3-97.7; P =.004]).Conclusions: Fistulotomy is the preferred operation for anal fistula. Plugging is associated with the highest operative failure and septic complication rates. Incontinence was influenced more by fistula type and age rather than procedure.

Endorectal Advancement Flap

“…Mizrahi et al found an increased risk in the presence of prior attempts at repair [ 10 ]. Abbas et al found an increased risk of incontinence with older age and high transsphincteric fi stulas, but the majority of the patients in this study had fi stulotomies, with only 10.6 % of patients having advancement fl aps [ 13 ]. Although there is little data with which to counsel patients, the patients at higher risk for incontinence after advancement fl ap are likely those who are at higher risk with any procedure-those with baseline disturbances in continence, prior repairs, women, and older individuals.…”

“…A higher recurrence rate has been found with fl ap as compared to fi stulotomy [ 25 , 48 , 51 ], although one study found no difference in recurrence rate [ 13 ]. However, the problem with comparing these two methods, as acknowledged by many of the authors of these studies, is that endorectal advancement fl ap is generally used in situations where a fi stulotomy would be associated with an unacceptably high risk of incontinence, either due to the high location of the fi stula or due to preexisting impaired continence.…”

“…"Complex" fi stulas (horseshoe, suprasphincteric, or anovaginal fi stulas or those with other extensions) have not been found to have lower healing rates than more straightforward fi stulas [ 28 , 30 ]. Fistulas with a horseshoe component have been found to have higher [ 34 ], lower [ 13 ], and similar [ 24 ] healing rates when compared to fi stulas without a horseshoe component. The healing rate for rectovaginal fi stulas was not found to vary by the location of the fi stula (high vs. low) or size of the fi stula opening by Pinto et al [ 22 ].…”

“…The mean time to recurrence has been found to range widely from a median of 8 weeks to 9 months [ 10 -12 ]. Some studies show the majority of recurrences occurring within the fi rst year [ 13 ], or even all recurrences occurring within the fi rst 3 months [ 14 ], while other studies have shown recurrences up to 55 months after surgery [ 7 , 15 ]. Studies designed specifi cally to examine the length of follow-up needed to capture all recurrences demonstrate that the majority of recurrences occur early.…”

To LIFT or to Flap? Which Surgery to Perform Following Seton Insertion for High Anal Fistula?

“…1,2 If this is performed in patients with high fistulas, there is a real risk of fecal incontinence. 3,4 In such a situation, it is not infrequent that a seton would be inserted to ensure continual drainage of any sepsis before any subsequent definitive intervention.…”