Dimitrios Filippiadis, MD, PhD, MSc, EBIR
Assistant Professor of Diagnostic and Interventional Radiology
2nd Department of Radiology, University General Hospital "Attikon", National and Kapodistrian University of Athens, Greece
Objective : To evaluate pain tolerability during liver microwave ablation with continuous or pulsed energy delivery mode by comparing the self-reported pain scores of patients
Methods : During the last 6 months 24 patients underwent liver ablation; patients were prospectively evaluated and randomized into continuous mode (CM – 12 patients) and pulsed mode (PM – 12 patients) groups. All ablation sessions were performed under Computed Tomography-guidance and IV analgesia (paracetamol 1g + tramadol 100ml – same anaesthesia protocol in all 24 patients). Group CM included 6 HCC and 14 metastatic [colon(9), pancreatic (1), breast (2), bronchogenic (2) carcinoma] treated lesions; depending on location CM group included 6 sub-capsular and 14 lesions at least 2 cm away from liver capsule. Group PM included 6 HCC and 12 metastatic [colon(8), pancreatic (1), breast (2), bronchogenic (1) carcinoma] treated lesions; depending on location PM group included 8 sub-capsular and 10 lesions at least 2 cm away from liver capsule. Immediately upon completion of the ablation session all patients were asked to complete a pain score questionnaire with a 0-10 numeric pain scale.
Results : The mean pain score was 8.17±1.850 in CM group and 4.50±1.567 pain units in PM group. There was a statistically significant difference of 3.667±2.807 pain units (p =0.001). No complications were noted in CM group; there were two grade I complications according to the CIRSE classification system (small peri-hepatic haemorrhagic fluid collections).
Conclusions : Pulsed mode of microwave ablation seems to be less painful for patients undergoing liver ablation under IV analgesia, rendering this mode an attractive alternative whenever anesthesiologist is not present.