Chronic pain has a complex mechanism of formation and is often resistant to pharmacotherapy. The International Association for the Study of Pain recommends multidisciplinary approach including interventional techniques: local blockades and neurodestructive procedures. Neurodestructive procedures can be carried out using chemical (neurolysis), physical (temperature) or mechanical (surgical cutting) agents. Thermolesion is one of the invasive techniques which utilizes high temperature as a neurodestructive agent. It is a method based on controlled use of temperature above 45°C which is produced by radio waves spreading in tissues generated by RHF device. The procedure is enabled by a suitable device which preciously measures temperature and impedance and produces two kind of stimulation: sensory at a frequency of 50-100 Hz and motor at a frequency of 2-5 Hz. Th device is also equipped with a high frequency waves generator which produces accordingly programmed temperature in a strictly fixed time on the electrode tip. Measuring the impedance and two kinds of stimulation facilitate precise placing of the active electrode tip. The rest of the electrode is insulated by a synthetic material. Uninsulatd tip of the needle serves as an active electrode. Conducting thermolesion at temperatures 45-65°C enables selective lesion in mixed nerves, thin sensory fibres A delta and C without impairment of the functions of thicke motor nerves, resistant to this range of temperature. The indications for thermolesion are established when other noninvasive procedures failed especially when the effect of the diagnostic – prognostic blockade is possitive. Patients abusing drugs or alcochol and those whoe pain perception can be influenced by psychological and social agents are not elligible for the procedure. Thermolesion is carried out in such syndromes of chronic pain as: trigeminal neuralgia, cluster headaches, facet joint syndrome, occipital neuralgia, cancer pain, intercostal neuralgia, vascular pain, sympathetically maintained pain, stump limb pain (1, 2). The following analysis concerns the effect of thermolesion treatment of the pain in: painful shoulder syndrome, trigeminal and occipital neuralgia in the years 2009-2011.

The aim of the study was to assess the effectiveness and safety of the presented therapy.

Painful shoulder syndrome is a set of clinical symptoms related to the shoulder girdle characterized by pain, motor deficiency and impairment of the functions of the upper limb. It is often treatment resistant and inadequate therapy can lead to permanent motor impairment of the upper limb. The treatment of the painful shoulder syndrome ancompasses: noninvasive methods pharmacotherapy and physiotherapy and interventional procedures (supraclavicular nerve blockades, thermolesion, and surgery).

The study was conducted among the patients of Pain Clinic of Department of Anaesthesiology and Intensive Therapy of the Medical Center of Postgraduate (Education/Studies) in Warsaw in 2009-2011 diagnosed with a painful shoulder syndrome with intensity of pain > 6 in numerical rating scale NRS (11 points scale in which 0 – means no pain, and 10 – worst pain imaginable). After series of blockade of the supraclavicular nerve with positive but transient effect, thermolesion of supraclavicular nerve was performed. 20 patients (13 women, 7 man) aged 56-82 years were enrolled into the study. The chronic pain had lasted from one to 8 years. The written informed consent was obtained from the all patients. The thermolesion was applied ambulatorily with the use of Neuro-Therm RDG R/JK2C device and the electrode Top Nekropole Needle (EQUIPP MEDIKEY B.V.) the lenght of 6 cm (lentght of the uninsulated tip 5 mm). Th correct positioning of the active electrode tip was verified by means of sensory (50 Hz) and motor (2-5 Hz) stimulation. The place of lesion was anaesthetized by injection of 1 ml 2% lignocaine (ASTRA ZENECA). The time of lesion was 60s, voltage 21 mV, intensity 50 mA. The current characterized by such parameters generates a temperature of 65°C at the tip of active electrode. After application, 1 ml (20 mg) of pentoxyphylline was given. The efficacy of the procedure was evaluated on the basis of NRS in chosen time points (before the procedure, 14, 30, 60 days after the procedure). The duration of pain reduction and the occurence of side effects was also estimated.

The intensity of pain before the thermolesion was 7-10 point in NRS score. The pain relief was observed in 18 out of 20 patients (90%). In 13 patients (65%) the intensity of pain decreased to 2-4 points in NRS in all time points after the procedure. In 5 patients (25%) complete pain relief was achieved. In 2 patients (10%) no improvement was observed after the thermolesion. The average time of pain reduction was 5 moths. The complications observed in our patients, such as hyperaesthesia and increased muscle tension retreated spontaneously in 2 weeks. The thermolesion was carried out again in 7 patients (35%) with recurrance of complaints.

The thermolesion of the supraclavicular nerve has been carried out in our Pain Clinic since 2008. Previously we had treated the painful shoulder syndrome with blockades of supraclavicular nerve with the use of local anaesthetic agent and with steroid addition in chosen patients. The efficacy of thermolsion was high in our material. In 18 out of 20 patients (90%) treated with the discussed method significant improvement was achieved. In similar studies decrease of pain about 95% and improvement of motor function of the limb is reported. Technical precision in performing thermolesion and accuracy in assigning patients to the procedure results in low incidence of serious complications. Hyperaesthesia and increased muscle tension observed in our patients subsided spontaneously in 2 weeks. We didn’t observed decrease of muscle strength. No serious side effects have been observed in similar studies either. Only transient sensitive disorders appeared (3, 4). The preferable method in this technique of thermolesion is now pulsative thermolesion. It is our plan in the nearest future to also use this method of treatment after the purchase of suitable device.

The positive effect of the procedure in 18 out of 20 patients confirms the efficacy of the supraclavicular nerve thermolesion in the complex treatment of the painful shoulder syndrome. Low incidence of complications and their spontaneous retreat proves that the procedure is safe. Due to the long time of clinical improvement (5 months average) thermolesion is a useful alternative to the supraclavicular nerve blockades with the use of local anaesthetic agent in the complex treatment of painful shoulder syndrome.