Ultrasound Guided Ilioinguinal-Iliohypogastric Nerve Block Versus Ultrasound Guided Transversus Abdominal Plane Block for Post-Operative Analgesia in Open Inguinal Hernia Repair: A Randomised Controlled Trial

Open Inguinal Hernia surgery is one of the most commonly performed procedures across the world and is associated with about 60 percent moderate to severe post operative pain.

 This acute postoperative pain without adequate analgesia may lead to persistent postsurgical pain. The incidence of chronic postsurgical pain varies according to surgeries and is 5 percent to 35 percent in hernia surgery.

  For management of pain, in post operative hernia repair, various treatment modalities have been advocated. Most of them have been proved inconsistent. Despite of providing good analgesia, Opioids and NSAIDs are associated with several undesirable side effects.

 The major goal in the management of post-operative pain is to use minimal dose of medications to decrease their side effects.

 Regional nerve block techniques offer a great degree of post-operative pain relief thus facilitating early ambulation and discharge.

 Transversus abdominis plane contains intercostal nerves (T7-T11), subcostal nerves(T12), iliohypogastric and ilioinguinal nerves(L1)

 Transversus abdominis plane block [TAP]  has been extensively used for post operative analgesia after inguinal hernia repair.TAP block being a compartment block provides analgesia to the parietal peritoneum and sensation to anterior and lateral abdominal wall in infra-umbilical surgeries block it requires larger volume.

 Ilioinguinal-iliohypogastric nerve block, blocks the branches of T12-L1 and provide effective analgesia in inguinal hernia surgeries.

 Local anaesthetic is deposited in the plane between the internal oblique and transverse abdominis muscle in both TAP and IIL/IH block, but at different points along the course of nerve , with local anaesthetic being administered closer to nerve in IIL/IH block.

 IIL/IH block being more precise requires lower volume of local anaesthetic and so lesser anaesthetic toxicity, complications and more simplicity and efficacy than TAP block to achieve similar analgesic effect.

 There are few studies comparing IIL/IH and TAP block for post oprerative analgesia for inguinal hernia repair but results are conflicting.

 Hence, we would like to propose a study for comparison of ultrasound guided IL/IH nerve block and ultrasound guided TAP block for open hernia repair for post operative analgesia.