Two types of peripheral nerve block, lateral abdominal transversus abdominis plane block (TAP block) and iliohypogastric/ilioinguinal nerve block (IHINB), were found to be effective in reducing acute and long-term pain after inguinal herniorrhaphy. These study results were published in the Journal of Anesthesia.1
TAP block targets the branches of the T7-L1 spinal nerves within the lateral abdominal wall and is used in abdominal procedures such as inguinal hernia repair and total abdominal hysterectomy.2 IHINB blocks the ilioinguinal and iliohypogastric nerves, which arise from the T12-L1 spinal nerves, and is most commonly used in inguinal herniorrhaphy, as well as in cesarean section and orchiopexy.3 However, because IHINB is a truncal nerve block, it requires a smaller volume of anesthetic than TAP block, which is a field nerve block.1
Studies comparing the effect of these 2 techniques on pain associated with inguinal hernia repair are limited and often contradictory. In addition, pain control beyond 1 day postsurgery has not been evaluated for either method. In the current study, researchers led by Onur Okur, MD, from the Izmir Bozyaka Training and Research Hospital in Turkey, compared the safety and efficacy of TAP block vs IHINB under ultrasound guidance in patients undergoing inguinal herniorrhaphy.
A total of 90 participants were randomly assigned at a 1:1:1 ratio to receive TAP block, IHINB, or subarachnoid block as a control condition. Pain scores were measured using the numeric rating scale at 0, 2, 4, 6, 24, and 48 hours and at 1 and 6 months.
Compared with controls, patients receiving TAP and IHINB had significantly lower pain scores at all times. Pain scores were similar between the nerve block groups, except in a post hoc analysis, in which TAP block reduced pain to a greater extent than IHINB at 24 hours.
Time to first report of pain was longer in patients who had received TAP block or IHINB vs patients in the control group (TAP block, 266.6 minutes; IHINB, 247.2 minutes; control, 79.1 minutes; P <.001).
Patients treated with either nerve block were significantly less likely to require additional analgesics than controls. Additional analgesic requirements were similar between the TAP block and IHINB groups. Rates of adverse events were similar among the TAP block, IHINB, and control groups.
Summary and Clinical Applicability
Peripheral nerve blocks are commonly used during inguinal hernia repair, although the optimal technique and the long-term effects of nerve blocks were unclear until recently. Researchers found that TAP block and IHINB both reduce acute and chronic pain after inguinal herniorrhaphy.
“Truncal and peripheral nerve blocks ameliorate postoperative pain and reduce deleterious side effects resulting from use of opioid analgesics. Although TAP block and IHINB are both effective in reducing postoperative pain, TAP block is slightly more advantageous in management of acute postoperative pain in inguinal hernia repair,” Dr Okur told Clinical Pain Advisor.
“We found that performing either TAP block or IHINB also reduces additional analgesic requirements and the incidence of chronic postoperative pain. The latter is a particularly important finding, since there are few studies on the subject. Therefore, we strongly recommend that clinicians perform either of these blocks for inguinal hernia repair operations,” he added.
Because this was an open-label study, the lack of blinding may have introduced bias.
- Okur O, Tekgul ZT, Erkan N. Comparison of efficacy of transversus abdominis plane block and iliohypogastric/ilioinguinal nerve block for postoperative pain management in patients undergoing inguinal herniorrhaphy with spinal anesthesia: a prospective randomized controlled open-label study [published online June 14, 2017]. J Anesth. doi: 10.1007/s00540-017-2378-3
- Gasanova I, Alexander J, Ogunnaike B, et al. Transversus abdominis plane block versus surgical site infiltration for pain management after open total abdominal hysterectomy. Anesth Analg. 2015;121(5):1383-1388. doi: 10.1213/ANE.0000000000000909
- Findlow D, Aldridge LM, Doyle E. Comparison of caudal block using bupivacaine and ketamine with ilioinguinal nerve block for orchidopexy in children. Anaesthesia. 1997;52(11):1110-1113. doi: 10.1111/j.1365-2044.1997.204-az0346.x