Radiofrequency tissue ablation in an experimental model of grade IV renal trauma: a preliminary report

Efficacy and safety of radiofrequency, microwave and laser ablation for treating papillary thyroid microcarcinoma: a systematic review and meta-analysis

Background: To evaluate the efficacy and safety of radiofrequency ablation (RFA), microwave ablation (MWA) and laser ablation (LA) for treating papillary thyroid microcarcinoma (PTMC).Materials and methods: PUBMED and EMBASE were searched for studies on the efficacy and safety of RFA, MWA and LA for treating PTMC. The standard mean difference of the tumor volume before and after therapy and the proportion of complete disappearance, local recurrence, distant metastasis and complications were assessed using both fixed or random-effects modeling. Heterogeneity among studies was determined using the Q statistic for the pooled estimates and the inconsistency index I².Results: A total of 12 eligible studies, including a sample size of 1187 patients and 1284 PTMCs, were used. RFA, MWA and LA all showed a significant reduction in tumor volume of PTMCs (p < 0.05). Though MWA demonstrated superior efficacy over the other two therapies for volume reduction, the differences were not statistically significant. Additionally, the pooled proportion of complete disappearance after RFA was the highest (76.2%), and the pooled proportion of recurrence for RFA was the lowest (0.01%) among the three therapeutic methods, but no significant difference was detected. There was no event of distant metastasis during the follow-up in all of these studies. Few major complications were encountered; the pooled proportion of complications for RFA (1.73%), MWA (6.0%) and LA (0.92%) was low, revealing no significant differences (p > 0.05).Conclusion: RFA, MWA and LA are acceptable treatments to manage PTMCs in terms of efficacy and safety for non-surgical candidates.

Fast hemostasis: a win-win strategy for ultrasound and microwave ablation

Introduction

Hemorrhage is a serious complication following percutaneous biopsy requiring detecting and immediate treatment of active bleeding. This study aimed to explore the potential benefits of ultrasound (US)-guided microwave ablation (MWA) to treat acute hemorrhage in risky locations.

Materials and methods

We present seven patients (four males and three females) aged 19–69 years with solid-organ arterial hemorrhage treated by US-guided MWA and followed up with contrast-enhanced US (CEUS).

Results

All seven cases successfully underwent MWA for hemostasis, and their vital signs subsequently stabilized. During the follow-up from 13 to 36 days, the ablation area decreased slowly in five patients and was still stable in two cases. There were no complications observed in this study after MWA treatment. We also reviewed a total of 12 publications in the past 10 years.

Conclusion

This study suggested that US-guided MWA may be an effective and safe strategy for acute hemorrhage in the emergency setting. To confirm this method and benefit more patients, more prospective studies with larger samples and longer follow-ups are recommended.

Open versus Thoracoscopic RFA-Assisted Lung Resection

The purpose of this study was to evaluate Radio Frequency Ablation (RFA)-assisted lung parenchymal transection through thoracotomy and thoracoscopy. Twelve domestic pigs underwent RFA-assisted lingulectomy: six through thoracotomy (group A), and six with thoracoscopy (group B). There was no mortality, no bleeding, or air leak intra- or postoperatively in either of the groups, and no conversion to open thoracotomy in group B. Group A had longer operating period and more pleural adhesions. A barotrauma, a skin burn, and a localized infection were observed in this group. Histopathology confirmed a sharply demarcated area of coagulation necrosis without damage to adjacent structures. RFA-assisted lung resection through thoracotomy bears the inherent problems of an open approach, and the use of RFA device does not add to morbidity. The thoracoscopic use of RFA probe by experienced surgeons is considered safe, maintaining the advantages of key-hole surgery.

Contrast-enhanced sonographically guided thermal ablation for treatment of solid-organ hemorrhage: preliminary clinical results

The purpose of this series was to preliminarily evaluate the use of contrast-enhanced sonographically guided percutaneous thermal ablation in the evaluation and treatment of solid-organ bleeding by retrospectively analyzing 6 cases observed in clinical practice. Six patients who underwent contrast-enhanced sonographically guided thermal ablation for treatment of solid-organ bleeding (5 in liver and 1 in spleen) from December 2005 to August 2012 were included in this series. Clinical information, contrast-enhanced sonograms before and after ablation, and the ablation method were retrospectively collected and analyzed. In 5 of the 6 patients, the location of the bleeding lesion was clearly seen. Hemostasis was successfully achieved in 4 of these 5 patients: 1 by radiofrequency ablation and 3 by microwave ablation. Ablation failed to achieve hemostasis in 1 patient who had postbiopsy splenic arterial bleeding because the bleeding vessel was a thick branch of the splenic artery. In the sixth remaining patient, who had bleeding after liver biopsy, hemostasis failed because contrast-enhanced sonography did not precisely locate the bleeding lesion; hence, the ablation zone did not cover the whole lesion. Contrast-enhanced sonographically guided ablation can be an alternative choice for treating solid-organ bleeding because of its effectiveness and minimal invasiveness. However, it should be carefully investigated for those in whom the bleeding lesion cannot be located by contrast-enhanced sonography and in those who have bleeding in a large vessel.

Contrast-enhanced sonographically guided percutaneous 915-MHz microwave ablation therapy compared to local hemostatic drug injection in a renal artery injury model

OBJECTIVES

The purpose of this study was to show the contrast-enhanced sonographic features of various levels of renal artery rupture and to validate the therapeutic effects of percutaneous 915-MHz microwave ablation compared to hemostatic drug injection (batroxobin) using an in vivo canine renal artery injury model.

METHODS

Three renal artery hemorrhage models (A, diameter <1 mm, subcapsular artery; B, diameter 1-2 mm, interlobar artery; and C, diameter 2-3 mm, segmental artery) were created in 24 canines for this study. Contrast-enhanced sonography was used to show the bleeding features and guide hemostatic therapies using 915-MHz microwave ablation and local batroxobin injection. Success rates were assessed according to amounts of bleeding, times required for hemostatic action, and volumes of fluid infusion required using pathologic examination as a reference standard.

RESULTS

Contrast-enhanced sonography clearly showed renal artery ruptures with active bleeding at various levels and degrees and was very useful to make diagnoses and guide therapies. The success rate in the microwave treatment group was higher than that in the drug injection group (except group A; P< .05). The time required for hemostasis and the volume of fluid infusion required in the microwave group were notably less than those in the drug injection group (P < .05).

CONCLUSIONS

Contrast-enhanced sonography is a useful imaging method for assessing renal vessel injury and guide interventional therapies. Contrast-enhanced sonographically guided percutaneous 915-MHz microwave ablation is a preferred hemostatic technique for treatment of renal artery injury, with greater effectiveness and less tissue damage compared to local drug injection.

Video-assisted lung resection using radiofrequency ablation in a porcine model

BACKGROUND

The aim of this study was to assess the feasibility, efficacy, and safety of video-assisted lingula resection using radiofrequency ablation (RFA) with internally cooled electrodes in a porcine model.

MATERIALS AND METHODS

Six domestic pigs underwent RFA-assisted thoracoscopic lingulectomy. RFA was the only aerostatic and hemostatic method applied throughout the operation. After 30 d, the animals were sacrificed for the study of the macroscopic and microscopic effects of the technique.

RESULTS

No signs of pneumothorax, blood loss, or infection were observed up to 1 mo postoperatively. There was no mortality either during or after surgery. The histopathology of the lung revealed three clearly demarcated zone lesions.

CONCLUSIONS

Our study demonstrates that thoracoscopic lingulectomy using RFA energy is technically feasible. RFA energy is an effective and safe aerostatic and hemostatic method in the porcine model.

Radio Frequency Ablation (RFA)-assisted Pericystectomy for Hepatic Echinococcosis

The aim of this study is to describe an alternative technique, using radio frequency energy to perform pericystectomy for hepatic echinococcosis. We present 3 patients with hepatic echinococcosis who were treated with radio frequency ablation (RFA)-assisted pericystectomy. A Radionics Cooltip Radio Frequency System (Tyco, Greece, Radionics) with a single shaft 15 cm long needle electrode and a 2 cm exposure tip, was used. The needle electrode was inserted in consecutive sites into the "healthy" hepatic parenchyma close to the cyst wall, so that a tissue zone around the cystic cavity was gradually ablated. The complete ablation of a site was followed by sharp division of the parenchyma. The operation completed successfully in all patients. Minor bleeding and/or bile leakage were successfully controlled with RFA coagulation. No other hemostatic method was used. The postoperative course was uneventful. No evidence of recurrent disease, or any other cause of morbidity, has been demonstrated at follow up (2 y). RFA-assisted pericystectomy for hepatic hydatid disease in experienced hands, might be useful to perform a "sterile" resection, eradicating single or multiple cysts and preventing local recurrence, with minimal morbidity.

A novel spleen-preserving laparoscopic technique using radiofrequency ablation in a porcine model

BACKGROUND

Partial splenectomy is considered to be the optimal management for a variety of diseases. At the same time, laparoscopic procedures are increasingly used because they present certain advantages against their open counterparts. In this study, the safety and efficacy of radiofrequency ablation (RFA) were evaluated in laparoscopic partial splenectomy performed in a pig model.

METHODS

Eight domestic pigs were used. Four abdominal trocars were inserted under general anesthesia and the spleen was stabilized with laparoscopic clamps. A RFA needle electrode was inserted transcutaneously, and coagulative necrosis of a zone of the splenic parenchyma between the body and the lower pole was performed. Bloodless sharp division and removal of the lower pole followed. After 0, 7, 30, or 120 days, the animals were killed and examined.

RESULTS

Blood loss and operation time were minimal. Mortality and morbidity were zero. No abnormal findings were encountered during the postmortem abdominal exploration.

CONCLUSION

This study demonstrates the feasibility, safety, and efficacy of laparoscopic RFA-assisted partial splenectomy. The RFA-assisted laparoscopic partial splenectomy adds a novel technique to the surgeon's armamentarium for the preservation of a part of the spleen.