Pain is a common symptom associated with cancer. It is treated all over the world by using the WHO analgesic ladder approach and opioids along with some adjuvants remain the mainstay of treatment for cancer pain management. There are a few subset of patients who have progressive disease and continue to have pain despite heavy doses of analgesics. Such patients are treated with the help of regional nerve blocks/sympathetic neurolysis/epidural injections under image guidance. Recently a new subsection of regional blocks have been added to these categories which are known as field blocks. Transversus abdominis plane block is such a field block which initially had its utility for acute post-operative pain management in various types of surgeries, including different abdominal surgeries with accompanying laparotomy (including major abdominal surgeries), hernia repair, and cesarean delivery. Now it is being used for chronic cancer pain management too in cases where the patient is having intractable abdominal wall pain.
TAP block is given in the fascial plane between the internal oblique and the transversus abdominis muscle which is said to provide blockade to the mid/lower thoracic and upper lumbar spinal nerves too. Various approaches to TAP plane have been described in literature but commonly used ones include subcostal and lumbar triangle of Petit. These can be supplemented with rectus sheath block which acts on the terminal branches of the 7–11th intercostal nerves, penetrating the posterior wall of the rectus abdominis muscle thus providing a better coverage of sense organs near the midline of abdomen relative to TAP block.1 Lee KH et al and Hung CJ et al utilized TAP block for palliation of intractable abdominal wall pain and incorporated 33% alcohol in it to increase the duration for pain relief.2, 3
TAP neurolysis with alcohol can be done for palliative patients who have a multitude of symptoms and suffering from abdominal pain as a result of disease as well as some remedial procedures. It can be used for pain due to ascites, pig tail site pain, metastasis to abdominal wall and gastrostomy/feeding jejunostomy site pain. Efficacy of the procedure can be increased by performimg it under real time ultrasound guidance. By doing low concentration alcohol neurolysis in the TAP plane the duration of pain relief can be extended up to 17 days to 6 months. It is a simple day care procedure which is being done under local anaesthesia and is said to provide stability to the opioid consumption in palliative patients by providing analgesia to the anterior abdominal wall.
Dr. Sunny Malik
Department of Anaesthesia, Pain and Palliative Medicine
Rajiv Gandhi Cancer Institute & Research Centre (RGCIRC)
Niti Bagh, South Delhi