Radiofrequency ablation of benign cold thyroid nodules: initial clinical experience.

CONTEXT AND OBJECTIVE: To evaluate the efficacy and safety of ultrasound (US)-guided percutaneous radiofrequency (RF) ablation for benign cold thyroid nodules as a nonsurgical therapeutic modality. DESIGN, INTERVENTION, AND PATIENTS: A total of 35 benign cold thyroid nodules in 30 euthyroid patients (M:F = 2:28; mean age 39.1 years) underwent percutaneous RF ablation with a 1-cm-internally cooled electrode. Seventy-seven percent (23/30) of patients required conscious sedation for discomfort. We evaluated the tumor size, cystic component, vascularity (by color Doppler US), and the severity of mass-related symptoms before treatment. We assessed the therapeutic efficacy and safety of RF ablation by clinical and US follow-up (median 6.4 months). MAIN OUTCOME AND RESULTS: The volume of the tumors before ablation had a range of 0.6-28.2 mL (mean, 6.3 mL). The residual volume was 53.5% +/- 26.5% of original at 1.1-2.9 months (n = 32), 36.2% +/- 27.4% at 3.0-5.9 months (n = 20), 30.7% +/- 25.0% at 6.0-8.9 months (n = 15), and 11.8% +/- 10.9% at 9.0-18.5 months (n = 13). Mixed/mainly cystic tumors showed a significantly better response than mainly solid tumors (p < 0.05). Difference in vascularity did not affect the treatment response. Thyroid function after the procedure was maintained as normal in all patients. Eighty-eight percent of the patients reported an improvement of their symptoms. There was no major complication other than vocal cord palsy in one patient (3.3%). CONCLUSION: RF ablation may be an effective and safe nonsurgical technique to treat benign cold thyroid nodules.     

Radiofrequency ablation of liver tumors: experience with open and percutaneous approach.

BACKGROUND: Radiofrequency ablation (RFA), a thermal coagulation technique, has been used for ablation of primary and secondary liver tumors. METHODS: Over a 24-month period, 41 patients, including 20 with hepatocellular cancer (HCC), 14 with liver metastases from colorectal tumors and 7 with metastases from other tumors, underwent RFA in our institution. Ablation was done using intra-operative (n=27) or percutaneous ultrasonographic (n=14) guidance. A zone of ablation larger than the size of the lesion on CT scan indicated successful RFA. RESULTS: The mean size of lesions was 4.9 cm for HCC and 3.1 cm for metastases. Among 20 patients with HCC, 16 had complete tumor ablation and one had failure of localization. All patients with liver metastases had successful tumor ablation. There was no procedure-related death. Two patients had hemoperitoneum and one experienced skin burn. During a median follow up of 16 months, five patients with HCC and two with colorectal metastases died. One patient had tumor recurrence at the ablation site and two developed fresh solitary metastatic lesions; all three are disease-free after repeat ablation treatment. CONCLUSIONS: RFA is a safe and promising technique for the treatment of non-resectable HCC and liver metastases, in the short term.     

Radiofrequency catheter ablation of accessory pathways: A learning experience

Success rates of approximately 90% have recently been reported with radiofrequency catheter ablation of accessory pathways. This study determined whether this success could be repeated using a conservative approach generally limiting fluoroscopy time to 1 hour. Consecutive patients referred for management of arrhythmias associated with accessory atrioventricular pathways were included over a 9-month period. Ablation was attempted in 75 patients with 84 pathways. Overall success rate (including second attempts in 9 patients) was 60 of 84 accessory pathways (71%). Success rates for the first 3 months (n = 23) were 52%, the second 3 months (n = 23) 60% and the last 3 months (n = 38) 90%. Success rate varied with pathway location, with left lateral pathways having the best early success rates. Mean fluoroscopy time for successful procedures of 33 ± 21 minutes was shorter than the time for unsuccessful procedures of 63 ± 24 minutes (p = 0.001). There were no major complications and no patients with successful procedures (n = 53) have had recurrence of accessory pathway conduction or reciprocating tachycardia (follow-up 1 to 10 months). A conservative approach can yield success rates approaching 90% in a short time. The absence of major complications supports earlier reports suggesting that radiofrequency catheter ablation of accessory pathways is a reasonable first-line therapy in the Wolfff-Parkinson-White syndrome.     

Primary biliary cirrhosis: an Indian experience.

Primary biliary cirrhosis (PBC) is believed to be rare in India. We analyzed our data pertaining to patients with PBC seen in a tertiary referral center over a 5-year period. The diagnosis of PBC was based on liver biochemistry, histology and antimitochondrial antibodies, in the absence of biliary obstruction. Five patients, all women, were diagnosed to have PBC. Pruritus, jaundice and fatigue were the most common initial symptoms. Hepatomegaly was seen in 4 of 5 patients. Associated autoimmune diseases were present in 2 patients. All patients presented with mild hyperbilirubinemia (< or = 6 mg/dL) with disproportionately raised serum alkaline phosphatase level. AMA was positive in 4 patients. Liver biopsy showed stage III-IV disease in 3 of 4 patients. The clinical presentation and course of PBC in India are similar to the experience in the West.     

Haemospermia: an Indian experience

A study of 35 cases of haemospermia over a period of 7 years revealed that infection was the most common cause (40%), and in nine cases (28%) no cause for haemospermia was found. All the cases were screened for genitourinary TB, which was found to be a significant factor (14%) for haemospermia in the Indian context.     

Radiofrequency ablation of hepatic tissue: a new experimental animal model

BACKGROUND/AIMS: Experimental radiofrequency ablation has already been performed in healthy livers of porcine models, but not in less expensive and easy-to-manage rats, with devices capable of delivering radiofrequency ablation in the 20-30 g liver of such small animals being so far unavailable. METHODOLOGY: We experimented with a modified system of radiofrequency ablation of liver tissue in rat models developing a custom-made needle-microelectrode of very small dimensions (0.3x2 mm) and an electrode-tip cooling technique, based on saline solution infusion. We adjusted duration (seconds) and power (watts) of radiofrequency ablation letting them range between 5-50 seconds and 5-25 W, respectively, to obtain the greatest lesions with the least side effects. After sacrificing the animals, an accurate histological examination of the liver was made. RESULTS: It is possible to establish beforehand the diameter of thermal liver lesion on the basis of joules of applied energy. The greatest increase of liver thermal lesion diameter (8 mm) is obtained with a 250-joule (10 W for 25 seconds) thermal energy cooling the electrode-tissue interface. CONCLUSIONS: Experimental radiofrequency ablation in rat liver is an effective and cheap way to study its effects on healthy hepatic tissues. It might be the first step to treat experimentally caused liver tumors.     

Radiofrequency tissue ablation: physical principles and techniques for increasing coagulation necrosis

Radiofrequency tumor ablation has been demonstrated as a reliable method for creating thermally-induced coagulation necrosis using either a percutaneous approach with image-guidance or direct surgical placement of thin electrodes into tissues to be treated. Early clinical trials with this technology have studied the treatment of hepatic, cerebral, and bony malignancies. The extent of coagulation necrosis induced with conventional monopolar radiofrequency electrodes is dependent on overall energy deposition, the duration of radiofrequency application, and radiofrequency electrode tip length and gauge. This article will discuss these technical considerations with the goal of defining optimal parameters for radiofrequency ablation. Strategies to further increase induced coagulation necrosis including: multiprobe and bipolar arrays, and internally-cooled radiofrequency electrodes, with or without pulsed-radiofrequency or cluster technique will be presented. The development and laboratory results for many of these radiofrequency techniques and potential biophysical limitations to radiofrequency induced coagulation, such as perfusion mediated tissue cooling (vascular flow) will likewise be discussed.     

Radiofrequency ablation of an unresectable abdominal tumor

Remnant malignant tissue is left behind after conventional surgery for an unresectable intraperitoneal malignant tumor. Standard radiotherapy or chemotherapy rarely enables good tumor control. We report the case of a 74-year-old man who developed a local recurrence of a sigmoid tumor located 5 to 6 cm from the anus. The tumor was fixed to the pelvic wall and could not be totally eradicated with conventional surgery. Preoperative peroperative assessment confirmed the absence of metastatic spread. Radiotherapy could not be performed due to risk of bowel injury. Peroperative radiofrequency ablation was followed by surgical colorectal resection without restoration of intestinal continuity, leaving only tumor tissue destroyed by radiofrequency. No adjuvant treatment was proposed because of intolerance to chemotherapy. Clinical assessment and thoracic and abdominal CT scan confirmed the absence of recurrence 26 months after radiofrequency ablation. Serum markers remained normal.     

Radiofrequency ablation for sleep-disordered breathing.

Radiofrequency volumetric tissue reduction (RFVTR) has been applied to the nose, palate, and tongue as a treatment for sleep-disordered breathing. Data on the outcome of this procedure are very scant. When applied to the palate, RFVTR seems to be moderately effective for simple snoring. It has not been shown to be effective treatment for significant sleep apnea. Application of RFVTR to the tongue and turbinates has not been studied thoroughly enough to assess its efficacy at present.     

Radiofrequency ablation for chronic radiation proctitis: our initial experience with four cases

Background

Chronic radiation proctitis (CRP) occurs up to 20 % of patients after pelvic radiotherapy, with rectal bleeding as the main presenting complaint. Radiofrequency ablation (RFA) has recently been used in the management of Barrett’s esophagus, but its efficacy in CRP has to be studied. The aim of this case series was to describe four cases of patients with CRP treated with RFA that demonstrate the efficacy and safety of the technique.

Methods

All the procedures were performed with HALO 90 or HALO 90 Ultra ablation catheter fitted on the distal end of a standard flexible endoscope. For each patient, the severity of symptoms was assessed at baseline and after the last treatment session.

Results

At least two sessions of RFA (maximum 4) were necessary, at three-month intervals, to completely control the symptoms. No major complications were observed.

Conclusions

RFA was effective and safe for control bleeding in this case series. Adequately powered randomized controlled trials are needed to establish the safety and efficacy of RFA for CRP.     

Spectrum of right-sided infective endocarditis: an Indian experience.

We studied retrospectively 23 consecutive patients seen at our centre with right heart endocarditis. None of the patients had a history of intravenous drug abuse. All patients were found to have underlying congenital heart disease as a predisposing factor, of which ventricular septal defect (26%) and Fallot's tetralogy (26%) were the commonest. Postoperative endocarditis (26%) also constituted an important clinical subset. Fever (100%) and predominant pulmonary symptoms (69.5%) were the important presenting features. Congestive heart failure was present in 15 patients (65.2%) and predicted an adverse in-hospital outcome. Both the pulmonary and the tricuspid valves were affected equally with presence of vegetations at multiple sites in 10 patients (43.4%). Seven patients (30%) also had concomitant left-sided endocarditis. Medical therapy alone was successful in 15 patients (68.1%) with an overall in-hospital mortality of 31.8%. Five of 6 patients with postoperative endocarditis died, signifying an ominous prognosis of this subgroup when treated medically. The clinical spectrum of right-sided endocarditis in our country differs from the West. The frequent presence of underlying congenital heart disease, the rarity of drug abuse as a predisposing factor, equal involvement of the tricuspid and pulmonary valves and a greater incidence of congestive heart failure are some of these differences.     

射频消融术

导管射频消融术(ＲＦＣＡ)是十几年来发展很快的治疗快速性心律失常新技术,其治疗范围与适应证也不断扩大。它对电生理学家们提出了更高的要求和严峻的挑战,要求他们在短时间内对心动过速作出正确的诊断,熟练掌握导管操作技术和心脏的解剖结构等。我院自1990年成功地进行1例预激综合征射频消融治疗,至今已完成1800余例各种快速性心律失常的ＲＦＣＡ治疗。据此,本文将就目前ＲＦＣＡ治疗方法作一介绍。1　各种快速性心律失常ＲＦＣＡ适应证见1996年射频导管消融治疗快速心律失常指南[1]。2　房室折返性心动过速　　房室折返性心动过速(ＡＶＲ…     

Radiofrequency ablation for early oesophageal squamous neoplasia:Outcomes form United Kingdom registry

AIM:To report outcomes on patients undergoing radiofrequency ablation(RFA)for early oesophageal squamous neoplasia from a National Registry.METHODS:A Prospective cohort study from 8 tertiary referral centres in the United Kingdom.Patients with squamous high grade dysplasia(HGD)and early squamous cell carcinoma(ESCC)confined to the mucosa were treated.Visible lesions were removed by endoscopic mucosal resection(EMR)before RFA.Following initial RFA treatment,patients were followed up 3monthly.Residual flat dysplasia was treated with RFA until complete reversal dysplasia(CR-D)was achieved or progression to invasive Squamous cell cancer defined as infiltration into the submucosa layer or beyond.The main outcome measures were CR-D at 12 mo from start of treatment,long term durability,progression to cancer and adverse events.RESULTS:Twenty patients with squamous HGD/ESCC completed treatment protocol.Five patients(25%)had EMR before starting RFA treatment.CR-D was 50%at12 mo with a median of 1 RFA treatment,mean 1.5(range 1-3).Two further patients achieved CR-D with repeat RFA after this time.Eighty per cent with CR-D remain dysplasia free at latest biopsy,with median follow up 24 mo(IQR 17-54).Six of 20 patients(30%)progressed to invasive cancer at 1 year.Four patients(20%)required endoscopic dilatations for symptomatic structuring after treatment.Two of these patients have required serial dilatations thereafter for symptomatic dysphagia with a median of 4 dilatations per patient.The other 2 patients required only a single dilatation to achieve an adequate symptomatic response.One patient developed cancer during follow up after end of treatment protocol.CONCLUSION:The role of RFA in these patients re-mains unclear.In our series 50%patients responded at12 mo.These figures are lower than limited published data.     

Radiofrequency ablation of primary and metastatic liver tumors--4 years experience

BACKGROUND/AIMS: Radiofrequency ablation of primary and metastatic liver tumors has been shown to be one of the promising new modalities to treat or to palliate liver tumors. It has been used as a bridge to liver transplantation as well as an approach to recurrent tumors after resection. METHODOLOGY: We present a series of 78 cases, 39 females and 39 males with a mean age of 61 years, the RFA has been used either by laparotomy or percutaneously to treat 117 lesions. There were 32 cases of hepatocellular carcinoma, 35 metastases of colorectal cancer and 11 cases of other tumors. RESULTS: The mean number of lesions treated were 1.5 per case with a average size of 3.6 cm per lesion. All liver segments were compromised specially IV, VII, VIII. The morbidity was 28% and the mortality was 2.5%. In 20.5% of the cases we were able to find recurrence after the procedure, with a mean time of 10.5 months. CONCLUSIONS: The RFA procedure is safe, can be performed by different ways and in the group of patients who are candidates to liver transplantation, while waiting for the organ. For the metastatic diseases it does not substitute surgery but can be used in patients who cannot be operated.     

Radiofrequency ablation of multiple accessory pathways.

The aim of the study was to review the clinical and electrophysiological characteristics and results of radiofrequency catheter ablation in patients with multiple accessory pathways to compare them with those of patients with single accessory pathways. Electrophysiological study and radiofrequency catheter ablation were performed in 1010 consecutive cases with Wolff Parkinson White Syndrome. Presence of multiple accessory pathways was documented in 31 patients (3.1%); 30 had two, and 1 had three accessory pathways. Of the 63 accessory pathways, 42 were manifest and 21 concealed. Nine patients had Ebstein's anomaly associated with atrioventricular bypass tracts. The most common combination was right posteroseptal with right free wall bypass tracts (15 patients with 30 accessory pathways). Fifty-one of the sixty-three accessory pathways (81%) were ablated successfully without complications. The duration of the procedure was 100 +/- 58 min and the fluoroscopic time 40 +/- 17 min. A follow up of 5 +/- 3 years after ablation, demonstrated recurrences of six accessory pathways (9.5%). In conclusion, patients with multiple accessory pathways can be treated by radiofrequency ablation in only one session with a high success rate although slightly less than that in patients with a single accessory pathway (81% vs 93%, P<0.01).     

Profile of right-sided endocarditis: an Indian experience

The clinical profile of right-sided infective endocarditis in India was studied from a review of records of patients with infective endocarditis admitted to this hospital. From November 1982 to November 1989, 109 patients with infective endocarditis showed vegetations on cross-sectional echocardiography confirming the diagnosis of infective endocarditis. In 19 (17.4%) patients, only the right side of the heart was involved: specifically the tricuspid valve alone in 10; tricuspid and pulmonary valves in 4; tricuspid valve and right ventricular outflow tract in 1; tricuspid valve and right ventricular free wall in 1; pulmonary valve alone in 2; and bifurcation of pulmonary trunk in 1. Eleven patients (57.9%) had underlying congenital heart disease whereas the remaining 8 patients (42.1%) did not have any underlying heart disease. The latter group, therefore, had isolated right-sided infective endocarditis. Previous illnesses leading to isolated right-sided infective endocarditis were: puerperal sepsis in 4; septic abortion in 1; staphylococcal pneumonia in 2; and epididymoorchitis in one. Eight out of 11 patients with congenital heart disease did not report any previous illness. In the remaining 3, right-sided endocarditis followed cardiac surgery in one; dental extraction without prophylaxis in one; and pulmonary balloon valvoplasty in one. All patients with isolated right-sided infective endocarditis had features of septicaemia, but a murmur of tricuspid regurgitation was audible in only 4 (50%) of them. We conclude that, unlike western reports, the pattern of right-sided infective endocarditis in India is different. No drug addict with right-sided infective endocarditis was seen; puerperal sepsis and septic abortion were the commonest causes of isolated right-sided infective endocarditis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Radiofrequency ablation guided by contrast harmonic sonography using perfluorocarbon microbubbles (Sonazoid) for hepatic malignancies: an initial experience

Aim: Conventional contrast harmonic sonography has the technical problem of a short enhancement time during targeting of hepatic malignancies for radiofrequency (RF) ablation. This study investigated the effectiveness of contrast harmonic sonographic guidance using perfluorocarbon microbubbles (Sonazoid) during RF ablation of hepatic malignancies. Materials and Methods: Nodules were detected on contrast‐enhanced computed tomography, but could not be resolved clearly by B‐mode sonography. Sixty‐six patients (51 men, 15 women; mean age, 65.8 years) with 108 hepatic malignancies were enrolled. Fifty‐one patients with hepatocellular carcinoma and 15 patients with liver metastases were treated by RF ablation guided by contrast harmonic sonography using perfluorocarbon microbubbles for a target lesion identified as a defect image after the administration of contrast medium. Results: The maximal diameters of all tumours ranged from 0.7 to 3.5 cm (mean ± SD, 1.7 cm ± 0.9) on sonography. Complete tumour necrosis was achieved by a single session of RF ablation in 62 (94%) of the 66 patients, while two sessions were required for the remaining four (6%) patients. The average number of treatment sessions was 1.1 ± 0.3. In the post‐vascular phase, 105 (97%) of a total of 108 malignant hepatic tumours were depicted as a defect with a margin. Clinical courses have been satisfactory without any signs of local tumour progression during 1–12 months of follow‐up (mean, 4.3 months). Conclusion: Using perfluorocarbon microbubbles, contrast harmonic sonographic‐guided RF ablation is an efficient approach for guiding further ablation of hepatic malignancies that are not clearly demarcated by B‐mode sonography.