Objective: This study aimed to assess the safety and effectiveness of perianal block and total intravenous anesthesia (TIVA) together with a non-opioid multimodal analgesia for common anal operations and to compare their results between outpatient setting and inpatient setting.

Materials and Methods: This prospective study included 83 elective anal operations performed under perianal block and propofolbased TIVA between September 2016 and August 2017. Non-opioid analgesics include NSAIDs or selective COX-2 inhibitor, and paracetamol. Surgical outcomes were determined and compared between outpatient and inpatient surgery.

Results: This study included 42 inpatients and 41 outpatients-with average age of 44 years. Anal fistulotomy was the most common operation performed (n = 39, 47%) followed by hemorrhoidectomy (n = 33, 40%). No patient required additional anesthetic method to control pain during an operation. None experienced postoperative nausea and vomiting. Two patients (2.4%) had urinary retention requiring single catheterization. Average numerical pain scale (ranging 0 to 10) at rest and during defecation was 2.3+1.5 and 2.6+1.6 on the day of surgery, 2.3+1.3 and 2.6+1.3 on postoperative day (POD) 1, and markedly decreased to 0.1+0.3 and 0.1+0.3 on POD 7. Inpatient group had a non-significant lower pain score than outpatient group. There was no 30-day reoperation
or readmission.

Conclusion: Perianal block and propofol-based TIVA, together with opioid-sparing multimodal analgesia, were associated with
effective intra-operative pain control, mild postoperative pain and a low incidence of acute urinary retention following anal operations in both outpatient and inpatient setting.

Keywords: Perianal block, Total intravenous anesthesia, Multimodal analgesia, Anal surgery, Hemorrhoidectomy, Fistulotomy, Outpatient, Inpatient, Surgery, Pain