Comparison of compound methylene blue (methylene blue + ropivacaine) and bupivacaine liposome for pain control after mixed hemorrhoid surgery: A comprehensive analysis based on clinical studies.
Mai G, Yu J, Li J • The Journal of international medical research • 2026
Single-dose perianal infiltration of liposomal bupivacaine provides superior and more sustained postoperative analgesia than compound methylene blue in patients who have undergone mixed hemorrhoidectomy.
Key Findings
Results
Liposomal bupivacaine provided superior cumulative pain control over 72 hours compared to compound methylene blue following mixed hemorrhoidectomy.
Study enrolled 150 patients undergoing elective hemorrhoidectomy for stage III-IV mixed hemorrhoids, with 75 patients in each group
Pain was assessed using the numerical rating scale (NRS) at rest over 72 hours
The compound methylene blue group demonstrated marginally better pain control in the immediate postoperative period
Liposomal bupivacaine provided superior and stable analgesia from 12 to 72 hours post-surgery
Cumulative pain scores over 72 hours were significantly lower in the liposomal bupivacaine group
Results
The proportion of patients requiring rescue opioids was significantly lower in the liposomal bupivacaine group than in the compound methylene blue group.
Total rescue opioid consumption was a primary outcome measure
Time to first rescue analgesia was also measured as a primary outcome
Liposomal bupivacaine significantly reduced rescue opioid requirements and delayed the need for supplemental analgesia
This opioid-sparing effect was one of the key comparative endpoints of the study
Results
Patient satisfaction was significantly higher in the liposomal bupivacaine group compared to the compound methylene blue group.
Patient satisfaction was assessed as a secondary outcome
The liposomal bupivacaine group demonstrated significantly higher satisfaction scores
Recovery metrics were also evaluated as secondary outcomes alongside patient satisfaction
This was a single-center, prospective observational cohort study design
Results
The incidence of adverse events was significantly lower in the liposomal bupivacaine group than in the compound methylene blue group.
Adverse events were evaluated as secondary outcomes
Liposomal bupivacaine demonstrated a 'favorable safety profile' compared to compound methylene blue
Both treatments were administered as perianal infiltration in the context of mixed hemorrhoidectomy
The compound methylene blue formulation consisted of methylene blue combined with ropivacaine
Methods
This was a single-center, prospective observational cohort study comparing two analgesic approaches in patients with stage III-IV mixed hemorrhoids.
150 patients total were enrolled, with equal allocation of 75 patients per group
Patients underwent elective hemorrhoidectomy and were not randomized (observational cohort design)
Primary outcomes included cumulative pain scores, time to first rescue analgesia, and total rescue opioid consumption
Secondary outcomes included patient satisfaction, recovery metrics, and adverse events
The study was conducted at a single center, which may limit generalizability
What This Means
This research suggests that a long-acting local anesthetic called liposomal bupivacaine works better than a combination of methylene blue and ropivacaine for controlling pain after hemorrhoid surgery. In a study of 150 patients who had surgery for advanced hemorrhoids (stage III-IV), researchers found that while the methylene blue combination provided slightly better pain relief immediately after surgery, liposomal bupivacaine offered more consistent and effective pain control from 12 hours through 72 hours after the procedure. Patients who received liposomal bupivacaine also needed fewer additional pain medications, including opioids, and reported greater overall satisfaction with their care.
This research also suggests that liposomal bupivacaine was safer, with fewer side effects reported compared to the compound methylene blue group. Both treatments were given as a single injection around the anal area before or during surgery. The ability of liposomal bupivacaine to slowly release the anesthetic over time appears to explain its longer-lasting pain relief compared to the methylene blue compound, which may wear off more quickly despite providing slightly better early relief.
Pain management after hemorrhoid surgery is particularly challenging because the area has many nerve endings, making recovery quite uncomfortable. This research suggests that using liposomal bupivacaine as a single injection could help patients experience less pain, require fewer opioid pain medications, and feel more satisfied with their recovery. However, because this was an observational study at a single hospital rather than a randomized controlled trial, further research would be needed to confirm these findings more definitively.
Mai G, Yu J, Li J. (2026). Comparison of compound methylene blue (methylene blue + ropivacaine) and bupivacaine liposome for pain control after mixed hemorrhoid surgery: A comprehensive analysis based on clinical studies.. The Journal of international medical research. https://doi.org/10.1177/03000605261463066