Evaluation of Postoperative Anal Function after Seton Technique for Lateral or Anterior Lower Intrasphincter Fistula (Type II)

We assessed anal function after the Seton technique for lateral or anterior lower intrasphincter fistula (Type II) with special focus on the correlation of anal pressure and the period of rubber band installation. Anal resting pressure (ARP) significantly decreased at the point of POD one month and recovered to the vicinity of the preoperative value at six months, although there was no definite change of maximum voluntary contraction pressure. A significant positive correlation was obtained between the postoperative complaints and rubber dropout days, the decreasing rate of ARP. Preoperative high ARP and age such as younger and older are positively correlated with the postoperative decreasing rate of ARP. As for the duration of rubber band installation, the best satisfaction of the patient and minimum rate of decrease of ARP are acquired on POD 32 days. These results suggest that we can usually make the duration of rubber band installation at POD 32 days and peri-operative ARP monitoring may be efficient in the Seton technique for Type II fistula.