Enhanced-effect of hypertonic saline, acetic acid and their mixture on hepatic radiofrequency ablation: an experimental study

Objective: To compare the effects of hypertonic saline, acetic acid and acetic acid- hypertonic saline (AAHS) solution on the ablated volume produced by hepatic radiofrequency ablation (RFA) in rabbits in vivo, and to determine the optimal synergist for radiofrequency ablation. Methods: Thirty big-ear white rabbits were equally divided into group A (RFA alone), group B (RFA with 36% NaCl injection), group C (RFA with 50% acetic acid injection), group D (RFA with 50% AAHS injection), group E (50% AAHS injection alone), and group F (36% NaC1 injection alone), with five rabbits in each group. Follow-up exam with CT scanning was made. The experimental rabbits were sacrificed by stages. The livers were collected and fixed in 10% formalin. Both the longitudinal and transverse diameter of the necrosis lesion produced by radiofrequency ablation were measured, the results were compared among groups. Results: The difference in the lowest impedance value between group A and other groups was statistically significant (P<0.05), but no significant difference in the lowest impedance value existed between group B and group C (P>0.997). The persistent time of group A was significantly shorter than that of both group B and group D (P<0.05), while significant difference in persistent time existed between group C and group B or group D (P<0.05). The coagulation necrosis area in group B, C and D was significantly larger than that in group A (P<0.05). The transverse coagulation necrosis area of group D was the largest (P<0.05). Marked enhancement at the rim of coagulation necrosis lesions was observed on enhanced CT scans one week after the procedure. The coagulation necrosis lesions were obviously contracted three weeks after the treatment. Operation-related complications occurred in six rabbits (50%, 6/12). Peritoneal adhesion and ascites occurred in 4 rabbits receiving acetic acid (50%, 4/6) and in two rabbits not receiving acetic acid (33%, 2/ 6). Conclusions: Combination of RFA with 50% acetic acid-hypertonic saline injection can produce larger hepatic coagulation necrosis volume in experimental rabbits, the synergy of 50% acetic acid-hypertonic saline is superior to single pharmaceutical solution. (authors)