Pregabalin Versus Pulsed Radiofrequency Ablation for Treatment of Chronic Post-thoracotomy Pain

Pregabalin Versus Pulsed Radiofrequency Ablation of Dorsal Root Ganglion for Treatment of Chronic Post Thoracotomy Pain Syndrome

Chronic Post thoracotomy pain syndrome (PTPS) is defined PTPS as pain that develops or increases in intensity after a thoracotomy and persists beyond the healing process, that's to say at least 3 months after the initiating event. The pain has to be localized to the site of incision or, projected to the innervation territory of a nerve situated in this area or referred to a dermatome or Head's zone (after surgery/injury to deep somatic and visceral tissues The incidence of PTPS is 57% and 47% of patients at 3 and 6 months after thoracotomy, respectively.

Management of PTPS begins with prevention. Preventive strategies are based on multimodal preemptive and intraoperative analgesia. Treatment of PTPS is either pharmacologic treatment which is systematically initiated by first line drugs including tricyclic anti-depressants (TCA), serotonin-norepinephrine reuptake inhibitors (SNRI), gabapentinoids. Second-line treatments include topical lidocaine, capsaicin, and weak opioid analgesics (tramadol). Third line treatments consist of strong opioids (oxycodone, morphine) and subcutaneous botilinium toxin injection.

Other therapies for management of CPTP include such modalities as transcutaneous electrical nerve stimulation (TENS), Spinal cord and peripheral nerve stimulation, acupuncture and neurolysis using pulsed radiofrequency for intercostal nerve or dorsal root ganglio and cryoneurolysis for intercostal nerve. The mode of action of pulsed RF is not well-understood, but may include inhibition of excitatory C-fiber responses by repetitive, burst-like stimulation of A-delta fibers, global reduction of evoked synaptic activity and minor structural changes in nerve tissue; elicited by alterations in the function of the blood-nerve barrier, fibroblast activation and collagen deposition.

The aim of the work is to evaluate the effect of oral pregabalin and pulsed radiofrequency ablation (PRF) ablation of the dorsal root ganglion (DRG) in the treatment of chronic post thoracotomy pain syndrome, using Visual Analogue Scale (VAS) score.

Inclusion Criteria:

• ASA physical status III or IV
• Persistent pain score ≥ 5 on VAS for 3 months or more, not responding to traditional OTC analgesics

Exclusion Criteria:

• Patient refusal
• The presence of pathology that could account for a majority of persistent symptoms (e.g. recurrent cancer)
• coagulopathy
• Uncooperative patients