RESUMO
<p><b>OBJECTIVE</b>To investigate the optimal operative approach for the complicated anal fistula.</p><p><b>METHODS</b>One hundred and ninety-two cases with complicated anal fistula were randomly divided into minimally invasive operation group (through spatium intermuscular of anal sphincter) and fistula resection group. The operation time, bleeding time during and after operation, pain lasting time, healing time of incision, area of anal scar, anal malformation and function and post operative recurrence were observed and compared between the two groups.</p><p><b>RESULTS</b>Compared to those of fistula resection group, the operative time was (36.5+/- 15.3)min, bleeding time during and after operation (2.0+/- 0.5)d, postoperative pain lasting time (1.5+/- 0.5)d, healing time of incision (18.5+/- 5.5)d in minimally invasive operation group. All were shortened (P< 0.05), and the incidence of anal malformation (5.2%, P< 0.01) and partial anal incontinence (2.1%, P< 0.01) was lower. There was no significant difference in postoperative recurrence between the two groups.</p><p><b>CONCLUSIONS</b>The minimally invasive operation through spatium in termuscular of anal sphincter is superior to fistula resection on the management of complicated fistula.</p>