RESUMO
Objective To evaluate the clinical value of the real-time three-dimensional ultrasound in the diagnosis of the fistula-in-ano.Methods One hundred and eighteen fistula-in-ano patients were examined using conventional and three-dimensional ultrasound,the stereotaxis of interal opening and the shape of the fistula-in-ano were analyzed.Then the diagnosis results of ultrasound were compared with the surgery and pathology.Results In 1 1 8 patients,the accuracy of preoperative identifying internal opening by two-dimensional ultrasound was 85%,and 95% for three-dimensional ultrasound with statistically significant difference (χ2 =6.679,P <0.05).For complex anal fistula,the diagnostic accuracy rates of main fistula tract by three-dimensional ultrasound (100%,82/82 )was higher than that by two-dimensional ultrasound(95%,78/82),the difference was statistically significant (χ2 =4.100,P <0.05 ).In 82 cases of complex anal fistula,the diagnostic accuracy of branch fistula tract by two-dimensional ultrasound was 70%(57/82 ),the accuracy using three-dimensional ultrasound was 89% (73/82 ),there was statistically significance (χ2 =9.499,P < 0.05 ).Conclusions Three-dimensional ultrasound can accurately locate the interal opening of fistula-in-ano and determine the shape of fistula-in-ano,which provided the most intuitive information for clinical treatment and had high practical value.