RESUMEN
<p><b>OBJECTIVE</b>To assess the efficacy and safety of modified ligation of the intersphincteric fistula tract for simple transsphincteric perianal fistula.</p><p><b>METHODS</b>Seventy patients with simple transsphincteric perianal fistula between October 2012 and January 2014 in our department were prospectively enrolled. According to the random number table, patients were divided into two groups: modified-LIFT group (37 cases, from the external opening close to the fistula, dissect the external sphincter fistula to the intersphincteric groove by tunneling technique, resect the lateral free fistula) and LIFT group (33 cases). Clinical parametres before and after operation were compared, and results of pelvic electromyogram (EMG) and anorectal manometry three months after operation were analyzed to evaluated anal function.</p><p><b>RESULTS</b>The operative time, pain score, hospital stay, and healing time were not significantly different between the two groups (all P>0.05). During the median follow-up of 12 months (3-20 months), the healing rate in modified-LIFT group was 83.8% (31/37), which was significantly higher than 60% (20/33) in LIFT group (P=0.029). After operation, 4 patients had persistent unhealed wound, 2 recurred in modified-LIFT group, while 8 patients had persistent unhealed wound, and 5 recurred in LIFT group. No patients developed anal incontinence. By the pelvic EMG and anorectal manometry 3 months after operation, the duration of motor unit potential, occurrence of simple phase, mean resting pressure and maximun squeeze pressure were not significantly different.</p><p><b>CONCLUSION</b>Modified-LIFT procedure for the management of simple transsphincteric perianal fistulas is a simple and effective operation with higher healing rate and similar anal function as LIFT.</p>