Pancreatic cancer is associated with severe pain, morbidity, mortality, and poor survival [1]. It ranks as the fourth or fifth most common cause of cancer mortality [2]. The incidence of pancreatic cancer in India is 0.5–2.4 per 100,000 men and 0.2–1.8 per 100,000 women. According to Indian Council for Medical Research (ICMR) estimate from 2010 to 2020 there were 40402 pancreatic cancer patients in India based on National Cancer Registry Programme [3]. It has been observed that in advance stage of pancreatic cancer pain doesn’t respond to pharmacological treatment, analgesics, opioids, and adjuvant medication [4,5,6]. Along with pain and morbidity, quality of life is seriously affected in these patients, so in advance cases where pain doesn’t respond to medical treatment, pain management must be carried out with the help of minimally invasive percutaneous procedures and palliative care should be an early part of the overall therapeutic plan [7-9]. The sympathetic innervation of the abdominal viscera originates in the anterolateral horn of the spinal cord. Preganglionic fibres from T5 to T12 rather than synapsing with the sympathetic chain, these preganglionic fibres pass through sympathetic chain and ultimately synapse on the celiac ganglia. The greater (T5-T9), lesser (T10-T11), and least splanchnic (T12) nerves provide the major preganglionic contribution to the celiac plexus and transmit most nociceptive information from the viscera including distal oesophagus, stomach, duodenum, small intestine, ascending and proximal transverse colon, adrenal glands, pancreas, spleen, liver, and biliary system [10]. It has been shown that in patients with chronic abdominal pain, interruption of the coeliac plexus or splanchnic nerves can offer symptomatic relief by inhibiting pathways (nociceptive) from the abdominal viscera to the brain [11]. Neurolysis implies the destruction of neurons by placing a needle close to the nerve and either injecting neuro-destructive chemicals agent or producing damage with a physical method such as cold (i.e., cryotherapy) or heat (i.e., radiofrequency ablation, RFA). Pain arising from upper abdominal viscera, is managed by minimally invasive procedures when not controlled by pharmacological treatment via coeliac plexus or splanchnic nerves, either by chemical neurolysis or radiofrequency ablation of splanchnic nerves. The first report of chemical neurolysis for the treatment of pain was made, in 1863, by Luton who administered neurolytic agents into painful area. Neural blockade with neurolytic agents has been documented for the treatment of pain for over a century [12].
Absolute alcohol (99%) is a nonselective neurolytic agent and it’s perineural administration results in protein denaturation and neurolysis (Wallerian degeneration). Effect persists for a long time and provide analgesia for at least 3-6 months of duration [13]. Radiofrequency ablation (RFA) is an electrosurgical technique utilizing high frequency alternating current to heat tissues leading to thermal coagulation. When cells are heated above 45°C, cellular proteins denature, and cell membranes lose their integrity as their lipid component melts [14]. During RFA, a high frequency alternating current (350–500 kHz) flows from the un-insulated tip of an electrode into the tissue. Ionic agitation is produced in the tissue around the electrode tip as the ions attempt to follow the direction of the alternating current and it is this agitation which results in frictional heating in the tissue around the electrode [14-17]. As chemical neurolysis leads to protein denaturation of neural tissues so that inhibiting pain impulse. In the same way thermocoagulation of sensory nerves should also stop carrying pain impulse to brain. Thermo coagulation is a process in which nerves are heated up to 80 to 85 degrees centigrade by radiofrequency generator. Temperature rise is due to sodium and potassium ion’s oscillatory movement present in tissue. Rise in temperature causes thermocoagulation of protein in neural tissue that leads to inhibition of pain impulse to brain.
There are few studies regarding comparison between radiofrequency ablation and chemical neurolysis of thoracic splanchnic nerves indicating superiority of study in terms of pain relief and better quality of patient life. So, we have decided to compare these two techniques in patients suffering from upper abdominal pain due to cancer of upper abdominal organs like lower one third part of oesophagus, stomach, small intestine, large intestine up to splenic flexure of colon, pancreas, liver, gallbladder which are likely to affect normal anatomy of celiac plexus. |