The Impact of Methylene Blue on the Quality of Recovery in Patients Undergoing Hemorrhoidectomy

Classical hemorrhoidectomy is known to be linked with significant postoperative pain, which can result in patient discomfort, extended hospital stays, and increased costs. The Quality of Recovery (QOR) score serves as an objective measure of patient-centered general health status following surgery and anesthesia. The latest version, QOR-15, is known for its time-efficiency, high rate of response, and completion, and has been validated in patients undergoing a range of surgical procedures.

Methylene blue (MB) is a water-soluble thiazine dye used to treat various conditions and has been found to have a unique analgesic property through the temporary disruption of anal sensory nerve terminals in patients. Studies conducted in Singapore and China have shown that perianal intradermal injection of MB provides temporary pain relief after hemorrhoidectomy and lateral anal sphincterotomy. However, there is limited published information regarding the impact of MB on the quality of recovery in anorectal surgery. This study aims to evaluate the effect of intradermal MB combined with ropivacaine injection on the quality of recovery for patients undergoing hemorrhoidectomy.

Study population Patients with symptomatic third- and fourth-degree hemorrhoids who are undergoing hemorrhoidectomy under spinal anesthesia and are admitted to the hospitals (145 for each group) will be prospectively enrolled in this study. Before participating, all patients or their caregivers will provide written informed consent. The protocol for this study has been approved by the Ethical Committee of Qilu Hospital of Shandong University with the protocol number Kyll-202405-041-2.

Intervention A standardized spinal anesthesia technique will be utilized, and between 7-9 mg of ropivacaine (Shijiazhuang Siyao Co., Ltd, 10ml:100mg) will be intrathecally injected between the L3 through L5 intervertebral spaces. All patients will undergo hemorrhoidectomy by colorectal surgeons with senior professional titles according to standard techniques. The postoperative analgesia regimen, with or without MB (Jichuan Pharmaceutical Group Co., LTD., 2ml: 20mg), will be determined at the discretion of the colorectal surgeon.

Data collection Clinical data, including age, sex, acute complications and total hospitalization cost, will be collected from the enrolled patients. The QOR-15 score will be calculated for all patients. Over a 6-month follow-up period, complications and the Wexner score for postoperative fecal incontinence will be recorded through telephone interviews.

Outcome measures The primary goal of this study is to evaluate the quality of recovery using the QOR-15 questionnaire, a comprehensive measure of recovery after surgery that assesses five dimensions: physical comfort (5 items), physical independence (2 items), emotional state (4 items), psychological support (2 items), and pain (2 items). Each item is rated on an 11-point scale based on its frequency on the questionnaire (higher scores indicate greater frequency for positive items and less frequency for negative items). The total score ranges from 0 (poorest recovery quality) to 150 (best recovery quality). Patients will complete the QOR-15 questionnaire at three time points: the day before surgery, postoperative day 1, and postoperative day 2 (between 4 pm and 6 pm). The postoperative day 1 score is the primary outcome of interest.

Additional assessments included the following:

The study will collect data on the Visual Analogue Score of pain at multiple time points (postoperative day 1, postoperative day 2, postoperative day 3, postoperative day 7, postoperative day 14), total hospitalization costs, dosage of analgesics three days and fourteen days after surgery, pain leading to unscheduled hospital returns or stay, and various complications such as urinary retention, fecal incontinence, itch and perianal paresthesia, secondary bleeding, perianal infection, poor wound healing at different postoperative time points (postoperative day 1, postoperative day, 1 month postoperative, 3 months postoperative, 6 months postoperative). Additionally, the Wexner score for postoperative fecal incontinence will be recorded at 1 month and 3 months postoperative.