IntroductionA concern for radiofrequency ablation of liver tumors was whether coagulopathy would occur similar to cryoablation. The aim of this study was to investigate the perioperative changes in d-dimer levels in patients undergoing laparoscopic radiofrequency ablation of liver tumors.Patients and MethodsSerum d-dimer levels were obtained perioperatively and quarterly in 551 patients undergoing laparoscopic radiofrequency ablation between 2000- 2007. The relationship between serum d-dimer and various perioperative parameters was analyzed. D-dimer levels >500ng/ml were accepted as elevated. Statistical analysis was performed with Kaplan-Meier, Cox proportional hazards and Anova. ResultsTumor type included colorectal cancer (295 patients), HCC (114 patients), neuroendocrine tumor (72 patients) and other tumors (70 patients). Preoperative serum D-Dimer levels were; 782.6±88 ng/ml in colorectal, 978±131 ng/ml in HCC, 603.9±116.6 ng/ml in neuroendocrine and 841.6±193 ng/ml in other tumor types. Preoperative d-dimer levels were elevated in 99 patients (33%) with colorectal, in 40 patients (35%) with HCC, in 16 patients (22%) with neuroendocrine and in 22 patients (31%) with other tumor types. On bivariate analysis, preoperative d-dimer levels correlated with liver tumor volume, only in patients with colorectal liver metastasis (p=0.007). Preoperative d-dimer levels correlated with alfa-fetoprotein and carcinoembriogenic antigen levels (p=0.01, r2=0.08 and p=0.004, r2=0.053, respectively), but not with chromogranin A levels. Age and gender did not affect preoperative D-dimer levels within a week after RFA, d-dimer levels increased by 10.6±1.3, 5.4±0.7, 16.9±2.8 and 11.3±1.9 folds in patients with colorectal, HCC, neuroendocrine and other tumor types, respectively. The magnitude of this increase correlated with the number of lesions ablated in all tumor types, but HCC. D-dimer levels returned back to baseline in 3 months. The postoperative increase in d-dimer levels was not associated with any coagulopathy or related clinical adverse events in any patient. ConclusionThis is the first systematic evaluation of the perioperative d-dimer profile in patients undergoing laparoscopic radiofrequency of liver tumors. D-dimer levels preoperatively correlate with tumor volume and tumor markers in certain tumor types. Despite postoperative elevations which return to baseline in 3 months, coagulopathy is not observed after laparoscopic radiofrequency ablation.