The effect of spermatic cord block on reducing the risk of vagal reflex during microsurgical subinguinal varicocelectomy: A randomized trial.

PURPOSE: This study aimed to compare the risk of vagal reflex during microsurgical subinguinal varicocelectomy (MSV) under general anesthesia (GA) with or without additional local anesthetic (LA) spermatic cord block (SCB).

METHOD: A single-center randomized controlled trial was conducted between January 2022 and June 2023.300 patients with left-sided grade Ⅲ varicocele were randomly divided into two groups: SCB group (n = 153) and control group (n = 147)（computer-generated random numbers list）. During MSV under GA, the SCB group was given of ropivacaine for SCB before pulling the spermatic cord, while the control group was directly lifted. The primary outcome was the reduction in the lowest heart rate in the SCB group as compared with the control group during spermatic cord traction (SCT). Secondary outcomes included the reduction in the lowest blood pressure in the SCB group as compared with the control group; and the reductions in the lowest heart rate and lowest blood pressure as compared with baseline during SCT. The number of times that surgery and medications were suspended because of symptomatic reflex bradycardia was also recorded. Adverse events were also recorded as secondary outcomes.

RESULT: Five patients in the SCB group and 10 patients in the CG were excluded. The lowest heart rate and systolic blood pressure during SCT in the SCB group and the control group were significantly lower than the baseline values (P < 0.05). However, the decrease in the SCB group (70-73bpm VS 108-115 mmHg) was milder than that of the control group（66-72 bpm VS 105-114 mmHg）(P < 0.05). The number of surgeries and medication pauses due to symptomatic reflex bradycardia during surgery was significantly lower in the SCB group (2 VS 1) than in the control group (9 VS 7) (P < 0.05).

CONCLUSION

SCB can effectively reduce the vagal reflex caused by pulling the spermatic cord during MSV, and reduce the risk of anesthesia and surgery.