Protocol of a clinical trial on the effectiveness of pudendal nerve block with and without neurostimulation in reducing posthemorroidectomy pain.

Introduction: Hemorrhoidal pathology is the most frequent proctological problem with a prevalence of 44% of the adult population. The most effective treatment is surgery but it also has the highest postoperative pain rate with moderate to severe pain rates of 30-40% during the first 24-48 hours. Here lies the importance of seeking measures to improve this situation, such as the pudendal nerve block with local anesthetic. However, the variability of the pudendal nerve sometimes makes its blockade ineffective and for this reason nerve location methods are sought to achieve a higher rate of success. The main aim of the study is to compare pain in the immediate postoperative period (24 h) after hemorrhoidectomy in patients with pudendal nerve block guided by anatomical references and guided by neurostimulation.

Methods: The present project proposes the performance of a single-center, triple-blind, randomized clinical trial of efficacy, carried out under conditions of routine clinical practice. Patients over 18 years old with hemorrhoids refractory to medical treatment, symptomatic grade III-IV and grade II hemorrhoids that do not respond to conservative procedures in a third level hospital in Spain and that are subsidiaries of surgery in major ambulatory surgery will be included. Demographic variables, variables on hemorrhoidal pathology, details of surgery, verbal numeric pain scale in the preoperative period and surgical complications will be collected.

Results: Not avaliable until the end of the study.

Conclusions: The pudendal nerve block guided by anatomical landmarks has been shown to be useful in postoperative pain control after hemorrhoidectomy although the use of the neurostimulator has not been well studied and we believe it may improve outcom.