Evidence Based Surgery: Pudental Nerve block is beneficial in hemorrrhoidectomy

A Pudental nerve block (PNB) is highly beneficial to patients undergoing hemorrhoidectomy reports a research published in the journal- Diseases of the colon & Rectum". This systematic review and meta-analysis demonstrated that PNB reduces opioid consumption, postoperative pain, complications, hospital length of stay and readmissions in patients undergoing hemorrhoidectomy.

Hemorrhoids is the third most common outpatient GI diagnosis with a significant negative impact on the quality of life. Medical therapy as well as noninvasive office-based procedures such as rubber band ligation or infrared coagulation are usually effective at early stages, but advanced disease often requires surgery. Excisional hemorrhoidectomy is one of the oldest and most widely used techniques.

Pain management in hemorrhoidectomy:

Optimal pain control is mandatory in hemorrhoidectomy, in particular, when patients are treated in a day care surgery setting, which is increasingly advocated in many countries to reduce health care costs. One important perspective in the management of posthemorrhoidectomy pain is the application of a multimodal pain control strategy. The PROSPECT (PROcedure-SPECific post-operative pain managemenT) Working Group emitted Grade A recommendations for pain management after hemorrhoid surgery including beyond conventional oral analgesics, oral diosmin, metronidazole, laxatives, topical application of lidocaine, glyceryl trinitrate, cholestyramine ointments, and infiltration with long-acting local anesthetics.

A recent evidence-based review has concluded that pudendal nerve block (PNB) is effective in controlling postoperative pain after colorectal surgical procedures. Likewise, PROSPECT recommendations stated that PNB was preferred over the simpler but apparently less effective perianal infiltration. Indeed, perianal anesthesia can be effective up to 6 hours, whereas PNB has been demonstrated to last longer. Pudendal nerve block with or without general anesthesia may also be preferred to spinal anesthesia thanks to its longer analgesic duration and lower rate of complications.

Conduct of study:

The researchers scoured major research databases (PubMed, Google Scholar, Cochrane Library and Web of Science) through December 2020, and identified randomized trials comparing PNB and any other treatment without PNB in patients undergoing surgical management for hemorrhoidal disease. Studies evaluating nonhemorrhoidal disease or with a sample size of fewer than 10 patients were excluded. The authors then used a random effects model to evaluate opioid consumption, pain on the Visual Analogue Scale, hospital length of stay and readmission rate. This approach allows for variable treatment effects identified in individual studies included in the meta-analysis to influence the average treatment effect identified in the meta-analysis. The approaches to PNB (nerve stimulation, ultrasound guidance and anatomic landmarks), type of anesthetic used, open versus closed hemorrhoidectomy, and control groups (placebo PNB vs. no PNB), varied among the studies. Postoperative pain values or opioid consumption were provided by all included studies.

Results:

• The authors identified 14 eligible studies with a total of 1,214 patients (565 PNB vs. 649 no PNB) to be included in their analysis.

• The overall difference in opioid consumption was 7.2 mg of morphine equivalents in favor of the PNB group (P<0.001), with a marked decrease in the number of patients requiring any opioids (22% PNB vs. 65% no PNB; P<0.001).

• Postoperative pain scores also were lower in the PNB group in all cases.

• Patients who received PNB also experienced less frequent postoperative complications, including urinary retention (2.9% vs. 23.4%; P<0.001), and postoperative nausea and vomiting (1.6% vs. 15.4%; P<0.001), as well as a shorter hospital stay (17.4 vs. 29.5 hours; P<0.001) and a lower readmission rate (1% vs. 10.7%; P=0.037).

• There was no difference in operative time or fluid administration between the two groups.

The meta-analysis is based on good-quality trials and supports wider use of PNB in hemorrhoidectomy. No major differences were found in opioid consumption related to approach (nerve stimulation vs. anatomic vs. ultrasound-guided) or type of anesthetic used.

Critical appraisal of the study:

As with all meta-analyses, this publication is subject to limitations related to publication bias and heterogeneity. However, based on the high-quality data used and similarity of included studies, these are likely to have minimal effect on the overall recommendation in favour of use of PNB for patients undergoing hemorrhoidectomy

Conclusion

This study strongly supports the use of PNB in hemorrhoidectomy—traditionally described as one of the most painful operations performed by colorectal and general surgeons—to assist in postoperative recovery, and should be considered by surgeons who perform this procedure as an adjunct to postoperative pain control.

Source: Pudendal Nerve Block in Hemorrhoid Surgery: A Systematic Review and Meta-analysis, mongelli et al. , (Dis Colon Rectum 2021;64[5]:617-631).