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Zavridis et al. Radio frequency neurolysis for pain reduction

by ongoing tissue damage) or neuropathic (caused step analgesic ladder.
by damage or dysfunction in the nervous system),
or mixed pain. [2,3] The World Health Organization METHODS
(WHO) analgesic ladder was introduced in 1986
as a simplified model of analgesics escalation. All patients were informed about the technique itself as
[4]
The three-step analgesic ladder proposed by WHO well as about possible benefits and complications. All
provides satisfactory pain management in a significant patients signed a written consent form for the procedure.
proportion of cancer patients. However, nearly one Authors have no conflict of interest to declare. No
third of oncologic patients complain of refractory industry support was received for this study.
[5]
(nonresponsive) pain. Despite its value, opioid
administration can be costly; additionally, dose and Patient selection
continuous use relate directly to risk of harm. [6,7] This is a retrospective study evaluating a consecutive
Recently, a fourth step was proposed for refractory series of patients undergoing CT-guided neurolysis
pain, which includes minimally invasive percutaneous using continuous radiofrequency ablation. During the
techniques. last 16 months, 22 patients (10 males/12 females)
suffering from cancer pain refractory to systemic
Radiofrequency ablation has been used since the therapy with opioids and adjuvant drugs were referred
1970s for chronic pain therapy in cases of refractory for percutaneous CT-guided neurolysis as palliative
pain. Ablation with continuous radiofrequency therapy for pain reduction. All patients treated had
results in high temperatures (60-80 °C) that promote no contraindications for regional blockade. Malignant
neurolysis and destroy the target nerves. [8,9] In background included pancreatic carcinoma (n = 8),
contrast, application of pulsed radiofrequency pancoast tumor (n = 5), lymphoma (n = 1), renal cell
maintains the temperature below 42 °C, promoting (n = 1), endometrial (n = 2), colon (n = 2) and ovarian
neuromodulation of the target nerves. [10,11] Both (n = 3) carcinoma. Patients underwent neurolysis
continuous and pulsed radiofrequency modes have by means of radiofrequency (Diros Technology In,
been applied for pain reduction in symptomatic cancer Ontario Canada) in celiac and splanchnic plexus (n =
patients with refractory pain. Percutaneous neurolysis 9), in thoracic (n = 1), in lumbar (n = 2), in superior
can be either chemical (phenol or alcohol injection) hypogastric plexus (n = 5) and in stellate ganglion (n =
or thermal (radiofrequency or cryoablation). During 5) [Figure 1].
continuous radiofrequency (RF) ablation an electrode
is placed close to a nerve fiber, applying energy which Technique
is transformed to high temperature causing protein All procedures were performed in the CT room, under
denaturation and destruction of the axons, resulting in anesthetic monitoring and strict aseptic technique by
transmission blockage of nociceptive signals from the two interventional radiologists with cooperation of an
periphery. [12] anesthesiologist. Unilateral or bilateral approach was
used, depending on the blockage that was performed.
The purpose of this study is to evaluate efficacy and The procedural route and site of the skin puncture were
safety of percutaneous computed tomography (CT)- determined with CT guidance. Once the puncture site
guided neurolysis using continuous radiofrequency for was located, local anesthetic (5-10 mL of Lidocaine
pain reduction in oncologic patients with pain refractory Hydrochloric 2%) was injected into the subcutaneous
to standard treatments proposed in the WHO three- soft tissue. Under continuous CT scans at the level

Figure 1: Cannullae are percutaneously placed in the desired location, most commonly under computed tomography guidance. Coaxially
10 mm active tip radiofrequency electrodes are inserted and connected to the generator. Motor and sensory tests are performed prior to the
neurolysis session
Journal of Cancer Metastasis and Treatment ¦ Volume 3 ¦ March 27, 2017 61