The Research of Feasibility and Efficacy of Radiofrequency Ablation in Treating Uterine Fibroids

To explore the feasibility and efficacy of radiofrequency ablation in treating uterine fibroids.Ninety patients with multiple uterine fibroids, who had undergone hysterectomy were included in the study. After the uterus was resected, the temperature of 60, 80, 100°C were adopted to ablate the in vitro fibroid with each temperature dealing with 30 patients. Simultaneously, 5 patients were included, whose in vivo fibroid were ablated with the temperature of 100°C before the fibroids were removed after laparotomy. After the fibroids were ablated, the smooth muscle in the ablated center (group A), the ablated edge (group B) and 1 cm away from the ablated edge (group C) were taken. Then, the samples were stained with hematoxylin and eosin (HE) to examine the histopathological changes, and immunohistochemistry was performed to detect the expression of estrogen receptor (ER) and progesterone receptor (PR).After radiofrequency ablation, the ablated lesions were round, toast tan, and dry on gross appearance. There were no obvious tissue carbonization and there were distinct boundary from periphery tissue. In vitro: On automated analysis, the average optical density of ER and PR in group A, B, and C was lower than the control group (P < 0.05), and which were gradually raised with the increased distance to electrode. In the same treatment group, ER optical density was gradually decreased with the increased temperature among 3 different groups. The PR optical density was decreased with the increased temperature under different temperatures in group A and group B, there was significant difference among groups (P < 0.05). But in group C, there was no difference in PR expression among the temperature of 60, 80, and 100°C (P > 0.05). In vivo: Compared with the control group, the average optical density of ER and PR were significantly different among group A, B, and C (P < 0.05), what''s more, it was gradually raised with the increased distance to electrode.After radiofrequency ablation, the tissues displayed coagulative necrosis, and decreased ER and PR expression. Radiofrequency ablation may be considered a minimally invasive alternative for those women who wish to retain their reproductive potential. Eighty degree Celsius was expected to be the optimum temperature in radiofrequency ablation treatment of uterine fibroid.     

CT-Guided Percutaneous Step-by-Step Radiofrequency Ablation for the Treatment of Carcinoma in the Caudate Lobe

The location of the caudate lobe and its complex anatomy make caudate lobectomy and radiofrequency ablation (RFA) under ultrasound guidance technically challenging. The objective of the exploratory study was to introduce a novel modality of treatment of lesions in caudate lobe and discuss all details with our experiences to make this novel treatment modality repeatable and educational.The study enrolled 39 patients with liver caudate lobe tumor first diagnosed by computerized tomography (CT) or magnetic resonance imaging (MRI). After consultation of multi-disciplinary team, 7 patients with hepatic caudate lobe lesions were enrolled and accepted CT-guided percutaneous step-by-step RFA treatment.A total of 8 caudate lobe lesions of the 7 patients were treated by RFA in 6 cases and RFA combined with percutaneous ethanol injection (PEI) in 1 case. Median tumor diameter was 29 mm (range, 18–69 mm). A right approach was selected for 6 patients and a dorsal approach for 1 patient. Median operative time was 64 min (range, 59–102 min). Median blood loss was 10 mL (range, 8-16 mL) and mainly due to puncture injury. Median hospitalization time was 4 days (range, 2–5 days). All lesions were completely ablated (8/8; 100%) and no recurrence at the site of previous RFA was observed during median 8 months follow-up (range 3–11 months). No major or life-threatening complications or deaths occurred.In conclusion, percutaneous step-by-step RFA under CT guidance is a novel and effective minimally invasive therapy for hepatic caudate lobe lesions with well repeatability.     

Cryoablation Versus Radiofrequency Ablation for Hepatic Malignancies: A Systematic Review and Literature-Based Analysis

The aim of this study is to summarize and quantify the current evidence on the therapeutic efficacy of cryoablation compared with radiofrequency ablation (RFA) in patients with hepatic malignancies in a meta-analysis.Data were collected by searching PubMed, Scopus, and Cochrane databases for reports published up to May 26, 2015. Studies that reported data on comparisons of therapeutic efficacy of cryoablation and RFA were included. The random effects model was used to estimate the pooled relative risks of events comparing cryoablation to RFA for therapy of hepatic malignancies.Seven articles met the inclusion criteria and were included in the meta-analysis. The meta-analysis showed that there was no statistically significant difference in mortality of at least 6 months (odds ratio [OR] = 1.00, 95% confidence interval [CI]: 0.68–1.49) and local tumor progression according to both patients (OR = 1.64, 95% CI: 0.57–4.74) and tumors (OR = 1.81, 95% CI: 0.74–4.38) between cryoablation group and RFA group. However, the risk of complications was significantly higher in the cryoablation group than that in the RFA group (OR = 2.93, 95% CI: 1.15–7.46). When considering the specific complications, only thrombocytopenia (OR = 51.13, 95% CI: 2.92–894.21) and renal impairment (OR = 4.19, 95% CI: 1.34–13.11) but not other complications were significantly higher in the cryoablation group.In conclusion, the 2 methods had almost equal mortality and nonsignificant difference in local tumor progression, with higher risk of complications in cryoablation. Further large-scale, well-designed randomized controlled trials are needed to identify the current findings and investigate the long-term effects of cryoablation compared with RFA for therapy of hepatic malignancies.     

Radiofrequency Ablation Versus Surgical Resection for Small Unifocal Hepatocellular Carcinomas

We aimed to compare the effectiveness and safety of hepatic resection and radiofrequency ablation (RFA) for small hepatocellular carcinomas (HCCs) less than 5 cm in diameter.A total of 289 patients were diagnosed with a small HCC (a single tumor no larger than 5 cm). Among these patients, 133 underwent hepatic resection, and 156 received RFA. Demographic data, intraoperative data, post-operative recovery data, and the baseline characteristics of the 2 groups of patients were compared. The incidence of post-operative complications; 1-, 3-, and 5-year survival rates; and tumor recurrence were determined.No statistically significant differences in the baseline characteristics were noted between the 2 groups. By contrast, operation time (P = 0.003), intraoperative blood loss (P = 0.000), and the length of post-operative hospital stay (P = 0.000) were significantly lower in the RFA group compared with the surgical resection group. The 2 groups displayed similar post-operative complication rates (12% or 16/133 in the liver resection group vs. 8.3% or 13/156 in the RFA group, P = 0.395). The 1-, 3-, and 5-year overall survival rates of the patients in the liver resection group were 88.7%, 78.2%, and 66.2%, respectively, whereas the rates in the RFA group were 90.4%, 76.3%, and 66.0%, respectively (P = 0.722). The 1-, 3-, and 5-year tumor-free survival rates of patients in the resection group were 87.2%, 69.9%, and 58.6%, respectively, whereas the rates in the RFA group were 85.9%, 66.0%, and 54.5%, respectively (P = 0.327). In addition, among HCC patients receiving RFA, patients with tumors no greater than 3 cm in diameter exhibited no significant differences regarding overall survival and tumor-free survival rates compared with patients with tumors 3 to 5 cm in diameter (all P > 0.05).RFA is an effective and safe treatment option for small HCCs and may be a preferred choice for HCC patients with small lesions.     

Radiofrequency ablation during continuous saline infusion can extend ablation margins

AIM:To determine whether fluid injection during radiofrequency ablation(RFA) can increase the coagulation area.METHODS:Bovine liver(1-2 kg) was placed on an aluminum tray with a return electrode affixed to the base,and the liver was punctured by an expandable electrode.During RFA,5% glucose;50% glucose;or saline fluid was infused continuously at a rate of 1.0 mL/min through the infusion line connected to the infusion port.The area and volume of the thermocoagulated region of bovine liver were determined after RFA.The Joule heat generated was determined from the temporal change in output during the RFA experiment.RESULTS:No liquid infusion was 17.3 ± 1.6 mL,similar to the volume of a 3-cm diameter sphere(14.1 mL).Mean thermocoagulated volume was significantly larger with continuous infusion of saline(29.3 ± 3.3 mL) than with 5% glucose(21.4 ± 2.2 mL),50%glucose(16.5 ± 0.9 mL) or no liquid infusion(17.3 ± 1.6 mL).The ablated volume for RFA with saline was approximately 1.7-times greater than for RFA with no liquid infusion,representing a significant difference between these two conditions.Total Joule heat generated during RFA was highest with saline,and lowest with 50% glucose.CONCLUSION:RFA with continuous saline infusion achieves a large ablation zone,and may help inhibit local recurrence by obtaining sufficient ablation margins.RFA during continuous saline infusion can extend ablation margins,and may be prevent local recurrence.     

Comparative Effects of Dexmedetomidine and Propofol on US-Guided Radiofrequency Ablation of Hepatic Neoplasm Under Monitored Anesthesia Care: A Randomized Controlled Study

Percutaneous radiofrequency ablation (RFA) is a useful and safe procedure for treating hepatic neoplasm. However, liver RFA causes severe pain, which thereby increases the demand for monitored anesthesia care (MAC). Here, we compared the efficacy and safety of propofol and dexmedetomidine, which are commonly administered during MAC when performing RFA to assess hepatic neoplasm.In this randomized controlled trial, 40 patients were randomly allocated to 2 groups for elective RFA. Patients received either dexmedetomidine (group D) or propofol (group P). Both groups received the continuous infusion of remifentanil for pain control. The primary outcomes were opioid consumption and differences in partial pressure of arterial carbon dioxide (PaCO₂) between pre- and postprocedure RFA. In addition, hemodynamic parameters, patient satisfaction, and interventional radiologist satisfaction were determined.There were significant differences in opioid consumption (50.1 ± 16.8 ng/kg/min [group D] vs 71.2 ± 18.7 ng/kg/min [group P]; P = 0.001) and delta PaCO₂ (10.4 ± 6.4 mm Hg vs 17.2 ± 9.2 mm Hg, respectively; P = 0.016). Moreover, respiratory rates were significantly different between groups during RFA (P < 0.001). However, blood pressure and heart rate did not significantly change during RFA. Neither patient nor interventional radiologist satisfaction was significantly different between groups.Dexmedetomidine provides better respiratory stability and reduces opioid consumption in comparison with propofol when administered under MAC when performing RFA for hepatic neoplasm.     

Radiofrequency ablation for treatment of hypersplenism: A feasible therapeutic option

We present a case of a patient with hypersplenism secondary to portal hypertension due to hepato-splenic schistosomiasis, which was accompanied by severe and refractory thrombocytopenia. We performed spleen ablation and measured the total spleen and ablated volumes with contrast-enhanced computed tomography and volumetry. No major complications occurred, thrombocytopenia was resolved, and platelet levels remained stable, which allowed for early treatment of the patient’s underlying disease. Previous work has shown that splenic radiofrequency ablation is an attractive alternative treatment for hypersplenism induced by liver cirrhosis. We aimed to contribute to the currently sparse literature evaluating the role of radiofrequency ablation (RFA) in the management of hypersplenism. We conclude that splenic RFA appears to be a viable and promising option for the treatment of hypersplenism.     

Radiofrequency ablation of pulmonary tumors and normal lung tissue in swine and rabbits

OBJECTIVE: The purpose of the present study was to examine the following during radiofrequency ablation (RFA): (1) the risk of hemorrhage from intrapulmonary large vessels; (2) the risk of incomplete ablation of pulmonary tumors; and (3) the late effect on lung tissue. MATERIALS AND METHODS: A 17-gauge, cool-tip-type radiofrequency electrode was used. The damage to the vessels and bronchi was examined by the injection of a colored silicone rubber, a liquid compound that hardens after injection. To examine the risk of hemorrhage from intrapulmonary large vessels, RFA was conducted at eight sites near the central pulmonary vessels in two swine. To examine the risk of an incomplete ablation for pulmonary tumors, 10 pulmonary nodules were made from a gelatin mixture in another two swine and were treated by RFA. To examine the late effect on lung tissue, RFA was conducted on the peripheral lung in 10 rabbits, and then the ablated regions were examined on days 1, 7, 14, 21, and 28 after RFA. RESULTS: The use of colored silicone rubber enabled us to examine the intrapulmonary vessels and bronchi for opening and leakage. RFA did not damage the large intrapulmonary vessels, even when they were located within the ablated regions. Lung tissue surrounding the gelatin nodules was hardly ablated over its entire circumference. Six of 10 gelatin nodules (60%) showed nonablated areas on the peripheral edges of the nodules. From 21 days after RFA, the ablated rabbit lung formed noninfectious cavities by communicating with the surrounding bronchi. CONCLUSION: It was improbable for hemorrhage to occur even when RFA was conducted near the large intrapulmonary large vessels. Because an incomplete ablation that left tumor cells at the site of ablation could occur during surgery due to the difficulty of ablating the entire tumor circumference, CT scan-guided RFA would be preferable to a surgical approach for making a safe margin. Cavity formation can occur beginning 21 days after RFA, which should be carefully followed up in a clinical setting to identify infection, especially in immunocompromised patients.     

Radiofrequency and cryoballoon ablation improve cognitive function in patients with atrial fibrillation

Atrial fibrillation is considered to be the most common arrhythmia in the clinic, and it gradually increases with age. In recent years, there has been increasing evidence that atrial fibrillation may exacerbate the progression of cognitive dysfunction. The current guidelines recommend ablation for drug-refractory atrial fibrillation.We aimed to prospectively analyze changes in cognitive function in patients with atrial fibrillation following treatment using different ablation methods.A total of 139 patients, with non-valvular atrial fibrillation, were included in the study. The patients were divided into the drug therapy (n = 41) and catheter ablation (n = 98) groups, with the catheter ablation group further subdivided into radiofrequency ablation (n = 68) and cryoballoon (CY) ablation (n = 30). We evaluated cognitive function at baseline, 3- and 12-months follow-up using the Telephone Interview for Cognitive Status-modified (TICS-m) test, then analyzed differences in cognitive function between the drug therapy and catheter ablation groups, to reveal the effect of the different ablation methods.We observed a significantly higher TICS-m score (39.56 ± 3.198) in the catheter ablation group at 12-month follow-up (P < .001), than the drug treatment group was. Additionally, we found no statistically significant differences in TICS-m scores between the radiofrequency ablation and CY groups at 3- and 12-month postoperatively (P > .05), although the two subgroups showed statistically significant cognitive function (P < .001).Overall, these findings indicated that radiofrequency and CY ablation improve cognitive function in patients with atrial fibrillation.     

Radiofrequency Ablation Versus Partial Nephrectomy in Treating Small Renal Tumors: A Systematic Review and Meta-Analysis

Radiofrequency ablation (RFA) has emerged as an alternative treatment to surgical partial nephrectomy (PN) in the treatment of small renal tumors (SRTs). But its safety and oncological efficacy are still controversial.We conducted this systematic review and meta-analysis to compare the peritoperative and oncological outcomes of RFA and PN in the treatment of SRTs.Pubmed, EMBASE, Cochrane CENTRAL, and Web of Science were searched to identify eligible studies that compared the RFA and PN in the treatment of SRTs.Twelve retrospective studies that compared RFA with PN in the treatment of SRTs met our selection criterion and were included in this meta-analysis. The pooled results indicated that the local recurrence rate (4.14% vs 4.10%, RR: 1.18, 95% CI: 0.68, 2.07, P = 0.550) and distant metastases rate (2.76% vs 1.89%, RR: 1.31, 95% CI: 0.70, 2.46, P = 0.686) were not significantly different between the RFA group and the PN group. In terms of perioperative outcomes, RFA was associated with shorter length of stay (LOS) (WMD: −2.02 days, 95% CI: −2.77, −1.27, P < 0.001), lower eGFR decline after treatment (WMD: −3.90, 95% CI: −6.660, −1.140, P = 0.006). However, the overall perioperative complication rate (7.5% vs 6.2%, RR:1.10, 95% CI: 0.64, 1.87, P = 0.740) and the major complication rate (3.7% vs 4.4%, RR: 0.83, 95% CI: 0.43, 1.60, P = 0.579) were both similar between RFA and PN groups.Compared with PN, RFA achieves an equal oncological outcome for SRTs with similar local recurrence rate and distant metastases rate. Additionally, RFA is associated with a similar perioperative complication rate, lower decline of eGFR, and shorter LOS. Therefore, RFA is an effective option in the treatment of SRTs for selected patients.     

Radiofrequency ablation for unresectable locally advanced pancreatic cancer: a systematic review

Background: Median survival in patients with unresectable locally advanced pancreatic cancer lies in the range of 9–15 months. Radiofrequency ablation (RFA) may prolong survival, but data on its safety and efficacy are scarce.Methods: A systematic literature search was performed in PubMed, EMBASE and the Cochrane Library with the syntax ‘(radiofrequency OR RFA) AND (pancreas OR pancreatic)’ for studies published until 1 January 2012. In addition, a search of the proceedings of conferences on pancreatic disease that took place during 2009–2011 was performed. Studies with fewer than five patients were excluded as they were considered to be case reports. The primary endpoint was survival. Secondary endpoints included morbidity and mortality.Results: Five studies involving a total of 158 patients with pancreatic cancer treated with RFA fulfilled the eligibility criteria. These studies reported median survival after RFA of 3–33 months, morbidity related to RFA of 4–37%, mortality of 0–19% and overall morbidity of 10–43%. Pooling of data was not appropriate as the study populations and reported outcomes were heterogeneous. Crucial safety aspects included ensuring a maximum RFA tip temperature of < 90 °C and ensuring minimum distances between the RFA probe and surrounding structures.Conclusions: Radiofrequency ablation seems to be feasible and safe when it is used with the correct temperature and at an appropriate distance from vital structures. It appears to have a positive impact on survival. Multicentre randomized trials are necessary to determine the true effect size of RFA and to minimize the impacts of selection and publication biases.     

Rapid Growth of Left Atrial Myxoma after Radiofrequency Ablation

Atrial myxoma is the most common benign tumor of the heart, but its appearance after radiofrequency ablation is very rare. We report a case in which an asymptomatic, rapidly growing cardiac myxoma arose in the left atrium after radiofrequency ablation. Two months after the procedure, cardiovascular magnetic resonance, performed to evaluate the right ventricular anatomy, revealed a 10 × 10-mm mass (assumed to be a thrombus) attached to the patient''s left atrial septum. Three months later, transthoracic echocardiography revealed a larger mass, and the patient was diagnosed with myxoma. Two days later, a 20 × 20-mm myxoma weighing 37 g was excised.To our knowledge, the appearance of an atrial myxoma after radiofrequency ablation has been reported only once before. Whether tumor development is related to such ablation or is merely a coincidence is uncertain, but myxomas have developed after other instances of cardiac trauma.Key words: Atrial fibrillation/prevention & control, catheter ablation/adverse effects, diagnosis, differential, echocardiography, transesophageal, echocardiography, transthoracic, heart neoplasms/ultrasonography, myxoma/diagnosis/surgery, pulmonary veinsRadiofrequency ablation (RFA) is an effective therapy for symptomatic patients with atrial fibrillation.¹ The reported complication rate after RFA is 3.9% to 22%,² including thromboembolism in 2% and an early mortality rate of 2% to 4% among all patients.³ Atrial myxoma is the most common cardiac tumor, but its appearance after RFA is very rare. We report a case in which an asymptomatic, rapidly growing cardiac myxoma arose in a patient''s left atrium after RFA.     

Resection or ablation versus transarterial therapy for Child-Pugh A patients with a single small hepatocellular carcinoma

Data from a direct comparison of the long-term survival outcomes of surgical resection (SR) or radiofrequency ablation (RFA) versus transarterial therapy in Child-Turcotte-Pugh (CTP)-class A patients with a single small T1/T2 stage hepatocellular carcinoma (HCC) (≤3 cm) are still lacking. This study retrospectively compared the therapeutic outcomes of these treatment types for CTP-A patients with a single small HCC.Using a nationwide Korean registry, we identified 2314 CTP-A patients with SR (n = 722), RFA (n = 731), or transarterial therapy (n = 861) for a single (≤3 cm) T1/T2 stage HCC from 2008 to 2014. The posttreatment overall survival (OS) of transarterial therapy with either SR or RFA were compared using the Inverse Probability of treatment Weighting (IPW). The median follow-up period was 50 months (range 1–107 months).After IPW, the cumulative OS rates after SR or RFA were significantly higher than those after transarterial therapy in all subjects (all P values < .05). The OS rates after SR or RFA were better than those after transarterial therapy in patients with the hepatitis B or C virus (all P values < .05), and in patients aged <65 years (all P values < .05). The cumulative OSs between RFA and transarterial therapy were statistically comparable in patients with a 2 to 3 cm HCC and aged ≥65 years, respectively. For all subjects, the weighted Cox proportional hazards model using IPW provided the adjusted hazard ratios (95% confidence interval) for the OS after SR versus transarterial therapy and after RFA versus transarterial therapy of 0.42 (0.30–0.60) (P < .001) and 0.78 (0.61–0.99) (P = .044), respectively.In CTP-A patients with a single (≤3 cm) T1/T2 HCC, SR or RFA provides a better OS than transarterial therapy, regardless of the HCC etiology (hepatitis B virus or hepatitis C virus), especially in patients with HCC of <2 cm and aged <65 years.     

Radiofrequency Ablation Versus Endoscopic Submucosal Dissection in Treating Large Early Esophageal Squamous Cell Neoplasia

Radiofrequency ablation (RFA) and endoscopic submucosal dissection (ESD) can potentially be applied for early esophageal squamous cell neoplasia (ESCN); however, no study has directly compared these 2 modalities.We retrospectively enrolled the patients with flat-type “large” (length ≥3 cm extending ≥1/2 of the circumference of esophagus) early ESCNs treated endoscopically. The main outcome measurements were complete response at 12 months, and adverse events.Of a total of 65 patients, 18 were treated with RFA and 47 with ESD. The procedure time of RFA was significantly shorter than that of ESD (126.6 vs 34.8 min; P < 0.001). The complete resection rate of ESD and complete response rate after primary RFA were 89.3% and 77.8%, respectively. Based on the histological evaluation of the post-ESD specimens showed 14 of 47 (29.8%) had histological upstaging compared with the pre-ESD biopsies, and 4 of them had lymphovascular invasion requiring chemoradiation or surgery. After additional therapy for residual lesions, 46 (97.9%) patients in the ESD group and 17 (94.4%) patients in the RFA group achieved a complete response at 12 months. Four patients (8.5%) developed major procedure-related adverse events in the ESD group, but none in the RFA group. In patients with lesions occupying more than 3/4 of the circumference, a significantly higher risk of esophageal stenosis was noted in the ESD group compared with RFA group (83% vs 27%, P = 0.01), which required more sessions of dilatation to resolve the symptoms (median, 13 vs 3, P = 0.04). There were no procedure-related mortality or neoplastic progression in either group; however, 1 patient who received ESD and 1 who received RFA developed local recurrence during a median follow-up period of 32.4 (range, 13–68) and 18.0 (range, 13–41) months, respectively.RFA and ESD are equally effective in the short-term treatment of early flat large ESCNs; however, more adverse events occur with ESD, especially in lesions extending more than 3/4 of the circumference. RFA does not allow for pathology to evaluate the curability after ablation, and thus currently the use for invasive ESCNs should be conservative until longer follow-up studies are available.     

心房颤动消融治疗临床应用的初步报告

目的评价EnSite/CARTO三维立体电标测系统心房颤动(Af)射频消融的临床效果.方法阵发性或持续性Af的患者14例,男性9例,女性5例,年龄47~75岁.14例患者连接EnSite或CARTO三维立体电标测系统,在X线和EnSite/CARTO三维立体电标测系统指引下构建左心房立体电标测结构图.之后,行右肺上下静脉和/或左肺上下静脉的环形隔离.结果所有患者均获得成功,平均随访时间为(213.21±102.76)d(30~302 d)无任何临床并发症.结论三维立体电标测指导下的肺静脉口外环形消融是安全有效的非药物治疗Af的手段.     

Long-term survival following radiofrequency ablation of lung metastases in an elderly patient with calcaneal osteosarcoma: A case report and review of the literature

Rationale:Recently, the number of osteosarcomas has been increasing in elderly patients due to human longevity. Lung metastases are the primary cause of death from osteosarcomas. Complete resection of lung metastases can prolong the survival. However, complete resection in elderly patients is often difficult due to high risk of operative complications. Computed tomography (CT) guided radiofrequency ablation (RFA) is a minimally invasive technique to destroy tumor nodules using heat. In this report, we present the first case older than 65 years applying RFA for lung metastases due to osteosarcoma.Patient concerns:A 74-year-old male presented with 1-year history of heel pain. A conventional high-grade osteosarcoma in his calcaneus was diagnosed. Below-knee amputation was performed. However, lung metastases were found in both lungs 1 year after amputation. CT-guided lung RFA was chosen since surgical intervention for lung metastases was abandoned because of tumor multiplicity and medical comorbidities. A total of 18 lung metastases were treated by CT-guided RFA. The most frequent complication was pneumothoraxes in 4 of 8 (50%) procedures and chest tube drainage was required in 2 of these (2 of 8 (25%) procedures).Diagnoses:Six lung metastases of osteosaroma were found in both lungs at 1 year after surgery.Interventions:CT-guided lung RFA was performed. A total of 18 lung metastases were treated in 8 lung RF procedures.Outcomes:The patient has been alive with disease for 5.5 years after the initial surgery.Lessons:CT-guided lung RFA is effective for elderly patients with osteosarcoma lung metastases in spite of discouragement of lung metastasectomy due to multiplicity of metastases and medical-comorbidities.     

Survival comparison between radiofrequency ablation and surgical resection for patients with small hepatocellular carcinoma: A systematic review and meta-analysis

Objective:This study aimed to evaluate and compare the long-term therapeutic efficacy of radiofrequency ablation (RFA) versus that of surgical resection in small hepatocellular carcinoma (HCC).Methods:Relevant articles in English from PubMed, EMBASE, and the Cochrane Library were retrieved. Pooled hazard ratios (HRs) were calculated to assess the prognostic value of RFA compared with that of surgical resection.Results:A total of 19 studies involving 15,071 patients were included. The combined HRs (95% confidence interval [CI]) of RFA for recurrence/relapse-free survival (RFS) and overall survival (OS) were 1.55 (95% CI = 1.29-1.86, I² = 72.5%) and 1.61 (95% CI = 1.29-2.01, I² = 60.4%), respectively, compared with surgical resection. In subgroup analyses according to study design, both RFS and OS of the prospective subgroups showed statistical significance, and no statistical heterogeneity existed between studies.Conclusion:Our clinical data suggest that surgical resection offers better long-term oncologic outcomes than RFA.     

Ferucarbotran expands area treated by radiofrequency ablation in rabbit livers

Background and Aim:  Several studies have examined the factors involved with expansion of the coagulation volume following radiofrequency ablation (RFA). Ferucarbotran contains superparamagnetic iron oxide that generates heat in a radiofrequency electric field and may have an effect on the area affected by RFA. We attempted to determine whether ferucarbotran administration expands radiofrequency-ablated volume using a rabbit model.
Methods:  A total of 15 male Japanese white rabbits (16 weeks old) were used and divided into three groups of five each. A 1-mL saline solution was given intravenously into a dorsal ear vein in the control group, whereas 1 mL ferucarbotran solution (0.016 mL/kg bodyweight) was given to the common-dose group and 1 mL of a twofold concentrated ferucarbotran solution (0.032 mL/kg bodyweight) was given to the high-dose group. RFA was performed with a cool-tip electrode 4 h after the administration and immediately thereafter the rabbits were killed, and the volume of the ablated area measured using magnetic resonance imaging (MRI). Following the MRI analysis, the rabbit's livers were resected, and the maximum short axis diameter of the ablated area in each was measured.
Results:  None of the rabbits died during the RFA procedure. The volume of the ablated area estimated on MR images in the ferucarbotran-administered groups was larger than that in the control group. Further, our macroscopic assessment showed that the maximum short axis diameter had a tendency to increase with ferucarbotran administration.
Conclusion:  Ferucarbotran may expand the area treated by RFA.     

Radiofrequency ablation in a porcine liver model： Effects of transcatheter arterial embolization with iodized oil on ablation time, maximum output, and coagulation diameter as well as angiographic characteristics

AIM:To evaluate the effects of combined radiofrequen-cy ablation and transcatheter arterial embolization with iodized oil on ablation time,maximum output,coagula-tion diameter,and portal angiography in a porcine liver model. METHODS: Radiofrequency ablation (RFA) was applied to in vivo livers of 10 normal pigs using a 17-gauge 3.0 cm expandable LeVeen RF needle electrode with or with-out transcatheter arterial embolization (TAE) with iodized oil (n = 5). In each animal,2 areas in the liver were ab-lated. Direct portography was performed before and af-ter RFA. Ablation was initiated at an output of 30 W,and continued with an increase of 10 W per minute until roll-off occurred. Ablation time and maximum output until roll-off,and coagulated tissue diameter were compared between the 2 groups. Angiographic changes on portog-raphy before and after ablation were also reviewed. RESULTS: For groups with and without TAE with iodized oil,the ablation times until roll-off were 320.6 ± 30.9 seconds and 445.1 ± 35.9 seconds,respectively,maxi-mum outputs were 69.0 ± 7.38 W and 87.0 ± 4.83 W and maximal diameters of coagulation were 41.7 ± 3.85 mm and 33.2 ± 2.28 mm. Significant reductions of abla-tion time and maximum output,and significantly larger coagulation diameter were obtained with RFA following TAE with iodized oil compared to RFA alone. Portography after RFA following TAE with iodized oil revealed more occlusion of the larger portal branches than with RFA alone. CONCLUSION: RFA following TAE with iodized oil can increase the volume of coagulation necrosis with lower output and shorter ablation time than RFA alone in nor-mal pig liver tissue.     

Temperature-Controlled Irrigated Tip Radiofrequency Catheter Ablation:

Temperature-Controlled Irrigated Tip Ablation. Introduction : In patients with ventricular tachycardias due to structural heart disease, catheter ablation cures < 60% partly due to the limited lesion size after conventional radiofrequency ablation. Irrigated tip radiofrequency ablation using power control and high infusion rates enlarges lesion size, hut has increased risk of cratering. The present study explores irrigated tip catheter ablation in temperature- controlled mode, target temperature 60°C, using an irrigation rate of 1 mL/min, comparing this to conventional catheter technique, target temperature 80°C.
Methods and Results : In vivo anesthetized pigs were ablated in the left ventricle. In vitro strips of porcine left ventricular myocardium were ablated in a tissue bath. Lesion volume was significantly larger after irrigated tip ablation both in vivo (544 ± 218 vs 325 ± 194 mm³, P < 0.01) and in vitro (286 ± 113 vs 179 ± 23 mm³, P < 0.01). The incidence of cratering was not significantly different between the two groups. In vivo, no coagulum formation on part of the catheter tip was seen after irrigated tip ablation as opposed to 52% of the applications with conventional ablation (P < 0.05).
Conclusion : We conclude that temperature-controlled radiofrequency ablation with irrigated tip catheters using low target temperature and low infusion rate enlarges lesion size without increasing the incidence of cratering and reduces coagulum formation of the tip.