Percutaneous radiofrequency ablation of hepatic tumors: postablation syndrome.

OBJECTIVE: Our objective was to define the spectrum and possible predictors of symptoms that occur in patients after percutaneous radiofrequency ablation of hepatic tumors. SUBJECTS AND METHODS: We performed 50 consecutive percutaneous radiofrequency ablation sessions on 39 patients with a total of 89 liver tumors. All patients had pre- and postablation laboratory studies and CT or MRI scans. After treatment, patients were followed for 3 weeks with a standardized questionnaire to assess for postablation symptoms. Comparisons of the presence or absence of symptoms were made for the laboratory test values, liver volumes, and pre- and postablation tumor volumes. RESULTS: Postablation symptoms occurred in 14 of 39 (36%) patients after 17 of 50 (34%) ablation sessions. Symptoms consisted of fever (16/17), malaise (12/17), chills (6/17), delayed pain (5/17), and nausea (2/17). On average, the symptoms presented 3 days after ablation and lasted 5 days. Statistically significant (p < 0.01) predictors of symptoms were tumor volumes > 50 cm3 (4.5 cm diameter), ablated tissue volumes > 150 cm3 (6.5 cm diameter), a difference between preablation tumor volume and the volume of tissue ablated > 125 cm3, or postablation aspartate aminotransferase levels > 350 IU/L. CONCLUSION: Approximately one third of patients undergoing percutaneous radiofrequency ablation of hepatic tumors develop delayed, transient flulike symptoms that can be treated conservatively and are significantly related to the volume of tissue ablated. Familiarity with this postablation syndrome should facilitate appropriate management of affected patients.

Blunt splenic injuries: high nonoperative management rate can be achieved with selective embolization.

BACKGROUND: This retrospective review tests the hypothesis that including selective splenic arteriography and embolization in the algorithm of a previously existing nonoperative management (NOM) strategy will result in higher rates of successful NOM in patients with blunt splenic injury. METHODS: All patients with blunt splenic injuries documented by computed tomographic scan and/or operative findings over a 24-month period at a Level I trauma center were reviewed. A previously published series from this institution of 251 patients with splenic injury (Group 1) was then compared with the patients that constitute this current review (Group 2). Group 2 was then compared with patients described in a previous publication advocating nonselective arteriography in blunt splenic injuries. RESULTS: Thirteen patients with blunt splenic injury in Group 2 underwent 14 splenic embolization procedures, with 12 (93%) being successfully treated without operation. Group 2 had a significantly higher NOM rate (82% vs. 65%, p < 0.01) than Group 1. These results are similar to the series published by Sclafani et al. (82.1% vs. 83.1%) in which every patient with splenic injury that was managed non-operatively underwent arteriography with or without embolization. CONCLUSION: A high rate of NOM can be achieved with observation and selective use of arteriography with or without embolization in the management of blunt splenic injuries.

Radiofrequency tissue ablation: effect of hepatic blood flow occlusion on thermal injuries produced in cirrhotic livers.

BACKGROUND: Radiofrequency thermal ablation has been used as a treatment for several types of hepatic malignancies. Many of these lesions exist in the presence of cirrhosis. Limitations exist to the size of the ablations and, subsequently, the efficacy of treatment. Hepatic vascular inflow occlusion has been advocated as an adjunctive measure to increase the efficacy of the ablation. We present a model in the human cirrhotic liver that demonstrates the advantage of blood flow occlusion during radiofrequency ablation. METHODS: Five patients with advanced endstage liver disease scheduled to have orthotopic liver transplantation were enrolled in this study. After laparotomy and before hepatectomy, radiofrequency ablation was performed without and with hepatic blood flow occlusion. After hepatectomy, the liver was sectioned, the area of ablation was measured in three dimensions, and the volume of ablation calculated. RESULTS: Three of the patients had had previously placed transjugular intrahepatic portosystemic shunt. The mean volume of the ablation without blood flow occlusion was 22.5 +/- 7.4 cm(3) and that with blood flow occlusion was 48.4 +/- 24.0 cm(3) (P =.05). CONCLUSIONS: Ablation area is increased significantly with hepatic blood flow occlusion in the human cirrhotic liver. This result may have application in the treatment of larger (>3 cm) hepatic malignancies.

Sonographically observed echogenic response during intraoperative radiofrequency ablation of cirrhotic livers: pathologic correlation.

OBJECTIVE: We performed a study to determine the correlation between the diameter of the echogenic response observed with intraoperative sonography during radiofrequency ablation of the cirrhotic liver and the mean diameter of tissue necrosis. SUBJECTS AND METHODS: A total of 22 intraoperative radiofrequency ablations were created in 11 cirrhotic livers. The largest diameter of the sonographically observed echogenic response surrounding and perpendicular to the radiofrequency probe was measured. The subsequent zone of necrosis observed at pathology in the hepatectomy specimens after liver transplantation was measured in three planes and compared with the measured diameter of the echogenic response. RESULTS: During all except three ablations, a hyperechoic region was visualized surrounding the radiofrequency probe. The diameter of the echogenic response correlated significantly with the mean diameter of necrosis (correlation coefficient, 0.84). However, the echogenic response overestimated the minimal diameter of necrosis (mean difference, 0.8 +/- 0.4 cm) in 18 of 22 ablations and underestimated the maximum diameter of necrosis (mean difference, 0.9 +/- 0.8 cm) in 16 of 22 ablations. CONCLUSION: The diameter of the echogenic response observed with intraoperative sonography during radiofrequency ablation of the cirrhotic liver correlates closely with the mean diameter of the subsequent area of tissue necrosis. However, the solitary diameter of the echogenic response as measured in our study was often greater than the smallest diameter and less than the largest diameter of the area of tissue necrosis. Therefore, the echogenic response associated with radiofrequency ablation of the cirrhotic liver should be viewed only as a rough approximation of the area of induced tissue necrosis; the final assessment of the adequacy of ablation should be deferred to an alternative imaging technique.