Electrosurgical burns in pediatric patients undergoing liver resection with saline-enhanced radiofrequency technology

Waveform Dependent Electrosurgical Effects on Soft Hydrated Tissues

Electrosurgical procedures are ubiquitously used in surgery. The commonly used power modes, including the coagulation and blend modes, utilize non-sinusoidal or modulated current waveforms. For the same power setting, the coagulation, blend and pure cutting modes have different heating and thermal damage outcomes due to the frequency dependence of electrical conductivity of soft hydrated tissues. In this paper, we propose a multi-physics model of soft tissues to account for the effects of multi-frequency electrosurgical power modes within the framework of a continuum thermomechanical model based on mixture theory. Electrical and frequency spectrum results from different power modes at low and high power settings are presented. Model predictions are compared with in vivo electrosurgical heating experiments on porcine liver tissue. The accuracy of the model in predicting experimentally observed temperature profiles is found to be overall greater when frequency-dependence is included. An Arrhenius type model indicates that more tissue damage is correlated with larger duty cycles in multi-frequency modes.

CT-guided radiofrequency tumor ablation in children

BACKGROUND

Image-guided radiofrequency ablation is a well-accepted technique of interventional oncology in adults.

OBJECTIVE

To evaluate the efficacy and safety of CT-guided radiofrequency ablation as a minimally invasive treatment for metastatic neoplasms in children.

MATERIALS AND METHODS

A total of 15 radiofrequency ablation sessions were performed in 12 children and young adults (median age 9.5; range 5-18 years) with metastatic malignancies. Seven children and young adults had secondary hepatic lesions, three had pulmonary and two had bone lesions. Radiofrequency ablation was performed under conscious sedation.

RESULTS

The median lesion size was 1.7 cm (range 1.3-2.8 cm). The median time for ablation was 8 min (range 7-10 min). Radiofrequency procedures were technically successful in all tumors. Postablation imaging immediately after, and 1 month and 3 months after radiofrequency ablation showed total necrosis in all patients. At 6-month follow-up, three patients (all with lesion size >2 cm) had local recurrence and underwent a second radiofrequency ablation session. At 2-year follow-up no patient had recurrence of the treated tumor. Post-ablation syndrome occurred in four children. No major complication occurred.

CONCLUSION

CT-guided radiofrequency tumor ablation was safe and efficient for palliative treatment in our cohort of patients.

Partial Splenectomy for Splenic Cyst using a Bipolar Radiofrequency Device

The main goals of spleen preserving surgery are control of peroperative bleeding and maintaining the spleen's function postoperatively. Several techniques of spleen preserving surgery have been described. This report presents a new technique to perform partial splenectomy. We performed this partial splenectomy with a bipolar radiofrequency (RF) device in a 21 years old woman with a splenic cyst, with almost no peroperative blood loss.

A phase 1/pilot study of radiofrequency ablation for the treatment of recurrent pediatric solid tumors

BACKGROUND

This prospective study was designed to be the first to evaluate the toxicity of radiofrequency ablation (RFA) in patients with recurrent pediatric solid tumors.

METHODS

From 2003 through 2008, a phase 1/pilot study of RFA for recurrent pediatric solid tumors was conducted. A multidisciplinary cancer management team selected appropriate candidates for the study. Imaging-guided RFA was performed percutaneously. Repeat RFA was performed for recurrences when appropriate. Toxicity and imaging response was assessed at 1 month and 3 months prospectively. Accrual stopped in 2006, and data collection stopped in 2008.

RESULTS

Sixteen patients (ages 4 years-33 years; median age, 15 years) and 56 tumor sites were treated in 37 RFA sessions including 38 pulmonary, 11 musculoskeletal, and 7 hepatic lesions (82 lesion-treatments). Postprocedural pain was moderate (median 5 on a scale from 1 to 10) and lasted a median of 9 days. Prolonged hospitalization (beyond 1 day) occurred 17 times (range, 2 days-25 days; median, 3 days). Hypoxia supported by supplemental oxygen occurred in 8 of 16 patients and resolved within 1 month after each RFA. No patient had tumor lysis syndrome but myoglobinuria/hemoglobinuria occurred in 6 of 16 patients, all without renal damage. Serious complications from pulmonary RFA included 2 diaphragmatic hernias. Of 82 lesions imaged, 24 (29%) remained ablated at the end of the study.

CONCLUSIONS

The toxicity from RFA of recurrent pediatric solid tumors was real but limited, and RFA may offer a local tumor control alternative in carefully selected cases.