Prospective Comparative Analysis of the Incidence of Vasovagal Reaction and the Effect of Rectal Submucosal Lidocaine Injection in Stapled Hemorrhoidopexy: A Randomized Controlled Trial.

Purpose: This study was performed to evaluate the incidence of vasovagal reactions (VVRs) and the efficacy of lidocaine injection for prevention.

Methods: One hundred seventeen patients diagnosed with hemorrhoids and scheduled to undergo a stapled hemorrhoidopexy (SH) were randomly divided according to submucosal injection to the rectum: lidocaine group (n = 53, lidocaine injected just before full closure of the stapler) and control group (n = 58). Outcomes included baseline patient characteristics (American Society of Anesthesiologists physical status classification, body mass index, diabetes mellitus, hypertension, and previous VVR history), vital signs during the operation, incidence of VVRs (hypotension, bradycardia, dizziness, diaphoresis, and nausea/vomiting), and postoperative complications (pain, bleeding, and urinary retention).

Results: Baseline characteristics were similar between groups. The number of patients with lower abdominal pain after firing the stapler and incidence of dizziness were lower for the lidocaine group than for the control group (9.4% vs. 25.9%, P = 0.017; 0% vs. 8.6%, P = 0.035, respectively). However, there were no significant between-group differences in incidence of nausea and diaphoresis (0% vs. 3.4%, P = 0.172) and syncope (1.9% vs. 3.4%, P = 0.612). Fewer patients in the lidocaine group complained of postoperative pain (41.5% vs. 58.6%, P = 0.072), and these patients used analgesics less frequently than those in the control group (28.3% vs. 36.2%, P = 0.374).

Conclusion: Patients who received a submucosal lidocaine injection prior to SH experienced less lower abdominal pain and dizziness compared with those who received standard treatment. A larger, more detailed prospective study is needed for further analysis.