Study on the Mechanism of Zuoqing San Promoting Postoperative Wound Healing of Anal Fistula by Inhibiting ROS-dependent NETosis

The First Affiliated Hospital of Anhui University of Chinese Medicine

This study adopted a randomized, double-blind, placebo-controlled clinical trial design to evaluate the efficacy and safety of Zuoqing San fumigation and washing on the wound healing after anal fistula surgery.

A total of 60 patients who underwent anal fistula surgery at the Second Affiliated Hospital of Anhui University of Chinese Medicine from September 2024 to March 2025 were included. They were randomly divided into the experimental group (treated with Left Qing San fumigation and washing) and the control group (treated with placebo fumigation and washing) at a ratio of 1:1.

Inclusion Criteria:

• Recurrent swelling and pain, along with pus discharge around the anus;
• Preoperative MRI or ultrasound confirmed the presence of the fistula;
• Underwent incision of the anal fistula, with the postoperative wound diameter ranging from 2 to 4 cm.

Exclusion Criteria:

1. Inflammatory bowel disease (such as Crohn's disease) related anal fistula;
2. Complicated with severe dysfunction of heart, liver and kidney (ALT/AST > 2 times upper limit, Cr > 1.5 mg/dL);
3. Pregnant or lactating women;
4. Those who are known to be allergic to the components of Zuoqing San;