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Sample records for percutaneous selective radiofrequency

  1. Percutaneous Radiofrequency Ablation of Nodal Metastases

    SciTech Connect

    Gervais, Debra A.; Arellano, Ronald S.; Mueller, Peter R.

    2002-12-15

    We report our experience with percutaneous image-guided radiofrequency (RF) ablation to treat isolated nodal metastases. Four patients underwent image-guided percutaneous RF ablation of metastatic disease involving retrocrural nodes,retroperitoneal nodes, or pelvic nodes. Coagulation necrosis was achieved in all cases.

  2. Percutaneous CT-guided radiofrequency ablation as supplemental therapy after systemic chemotherapy for selected advanced non-small cell lung cancers.

    PubMed

    Li, Xishan; Zhao, Ming; Wang, Jianpeng; Fan, Weijun; Li, Wang; Pan, Tao; Wu, Peihong

    2013-12-01

    The purpose of this study is to evaluate the safety and efficacy of percutaneous CT-guided radiofrequency ablation (RFA) as a supplemental therapy after systemic chemotherapy for selected patients with advanced non-small cell lung cancer (NSCLC). We retrospectively reviewed the medical records of 220 patients with advanced NSCLC who were treated with platinum-doublet chemotherapy between January 2000 and January 2012. Among them, 49 patients underwent RFA as a supplemental therapy for tumors in partial response or stable diseases after first-line chemotherapy. The progression-free survival (PFS) was evaluated by Kaplan-Meier method. There were nine women and 40 men (median age, 60 years; range, 24-82 years), including 28 patients with stage IIIb cancer and 21 with stage IV cancer. All 49 patients (partial response, 23 patients; stable disease, 26 patients) underwent 67 RFA sessions for 61 targeted tumors after systemic chemotherapy. There were no procedure-related deaths. Pneumothorax requiring chest tubes developed in eight sessions (11.9%). Thirty-one patients (63.3%) had complete response, 12 patients (24.5%) had partial response, six patients (12.2%) had stable disease, and no patients had progressive disease. The median follow-up period was 19 months (range, 6-34), and the median PFS was 16 weeks (95% CI, 14.5-17.5). Percutaneous CT-guided RFA can be performed as a feasible minimally invasive supplemental therapy with satisfactory PFS after systemic chemotherapy for patients with advanced NSCLC.

  3. Percutaneous radiofrequency ablation of renal cell carcinoma.

    PubMed

    Chiou, Yi-You; Hwang, Jen-I; Chou, Yi-Hong; Wang, Jia-Hwia; Chiang, Jen-Huey; Chang, Cheng-Yen

    2005-05-01

    Preliminary data regarding the use of percutaneous radiofrequency ablation (RFA) for the treatment of renal cell carcinoma (RCC) are encouraging, and show the technique to be associated with minimal morbidity. Thus, the current study was designed to evaluate the clinical applications, treatment efficacy, and complications of percutaneous RFA in RCC. From February 2003 to February 2004, 12 consecutive patients with histopathologically proven RCC underwent imaging-guided percutaneous RFA. The mean age of the patients (8 men and 4 women) was 76 years (range, 56-87 years), and mean tumor diameter was 3.7 cm (range, 2.2-8.0 cm). The efficacy of RFA was evaluated with contrast-enhanced, dynamic computed tomography (CT) performed 1 month after treatment, and then every 3 months. A Radionics device with an internally cooled electrode was used in 7 patients, and a radiofrequency interstitial tissue ablation (RITA) device with an expandable needle electrode was used in 5. Complete necrosis was defined as a lack of contrast enhancement in the treated region on follow-up CT studies. Overall, 16 sessions of RFA were performed for 12 solitary renal tumors in 12 patients: 8 patients underwent a single RFA session, whereas 4 had 2 sessions. Dynamic CT after RFA showed complete necrosis in 9 of 12 tumors. In 3 patients with tumors of 4.5-8.0 cm in diameter, enhancement of residual tissue was observed after RFA treatment, thus indicating residual tumor. Complete tumor necrosis was seen in all 5 tumors (100%) of diameter < or = 3.0 cm; 3 of 4 tumors (75%) of diameter 3.1-5.0 cm; and 1 of 3 tumors (33%) of diameter > 5.0 cm. A big subcapsular hematoma, which was found in 1 patient after RFA, resolved completely within 10 months without treatment; no serious complications occurred in the other 11 patients. Percutaneous RFA is effective in the treatment of RCC. It is most successful for tumors not larger than 3 cm in diameter, and has a satisfactory success rate in tumors of 3-5 cm in

  4. Osteoid osteoma of the cuboid managed by percutaneous radiofrequency ablation.

    PubMed

    Chakraverty, Julian; Al-Mokhtar, Namir; James, Steven L

    2014-01-01

    We present details of a case of osteoid osteoma of the tarsal cuboid bone. Osteoid osteoma arising in the foot is not very common, and localization in the cuboid is rare. To our knowledge, this is the first case of osteoid osteoma of the cuboid bone treated successfully by percutaneous radiofrequency ablation.

  5. [Potentials of interventional radiology: percutaneous radiofrequency ablation].

    PubMed

    Péter, Mózes; Tóth, Judit

    2004-02-15

    The efficacy of the treatment of hepatic malignancies has improved, mostly due to the physical procedures which affect the tumors locally. The authors performed 210 radio-frequency ablations in 1.38 patients. They recommend this procedure based on their experiences. RF treatment is performed together with other therapeutical procedures done by cooperation of oncology clinic. The main indication for the treatment of tumors is, lesions less than 4 cm in diameter and the number of masses is less than 4. The treatment can be performed by CT guidance and is documented well. The applied RF generator is made by Radionics, electrodes are cooled. In 68% of the tumors they achieved complete necrosis using this procedure. After the intervention patients experienced no serious complications. The only side effects were abdominal pain and discomfort. RF tumor ablation is an important and effective procedure in the treatment of hepatic tumors.

  6. Subclinical Breast Cancer: Minimally Invasive Approaches. Our Experience with Percutaneous Radiofrequency Ablation vs. Cryotherapy

    PubMed Central

    Manenti, Guglielmo; Scarano, Angela L.; Pistolese, Chiara A.; Perretta, Tommaso; Bonanno, Elena; Orlandi, Augusto; Simonetti, Giovanni

    2013-01-01

    Summary Background The aim of this study was to compare the efficacy of radiofrequency ablation vs. cryoablation in the treatment of early breast cancer. Patients and Methods 80 women (mean age 73 ± 5 years) with early breast cancer were retrospectively evaluated. 40 patients underwent cryoablation and 40 patients underwent radiofrequency ablation, both with sentinel lymph node excision. Tumor volume and histopatological data were compared by means of postprocedural 3.0-T magnetic resonance imaging (MRI). 30–45 days after the percutaneous ablation, all patients underwent surgical resection of the tumor. The mean follow-up was 18 months without any local recurrences. Results Both techniques allow good correlation with histopathological data. In 75 patients (93.8%) we observed complete necrosis; in 5 cases there was residual disease in the postprocedural MRI and postoperative histological examination. There was a good correlation between MRI volume and histologic samples. Cosmetic results were good in all patients but 2. Conclusion Both percutaneous radiofrequency ablation and cryotherapy are minimally invasive techniques with a good clinical and cosmetic outcome in selected cases. MRI examination is an ideal method to assess breast neoplasms in terms of quality and quantity as well as residual tumor extent after percutaneous ablation. Cryotherapy is the preferred method because of the analgesic effect of freezing with better patients compliance. PMID:24415989

  7. Transhepatic Approach for Percutaneous Computed-Tomography-Guided Radiofrequency Ablation of Renal Cell Carcinoma

    SciTech Connect

    Iguchi, Toshihiro Hiraki, Takao; Gobara, Hideo; Mukai, Takashi; Hase, Soichiro; Fujiwara, Hiroyasu; Tajiri, Nobuhisa; Sakurai, Jun; Mimura, Hidefumi; Saika, Takashi; Kumon, Hiromi; Kanazawa, Susumu

    2007-07-15

    We performed percutaneously radiofrequency (RF) ablation of 5 renal cell carcinomas (mean diameter 26 {+-} 15 mm) with computed-tomography (CT) fluoroscopic guidance using the transhepatic route. The RF electrode was successfully advanced into all tumors. RF ablation caused one minor complication (small asymptomatic perirenal hematoma); no major complications occurred. The follow-up contrast-enhanced CT images showed no local tumor progression of any tumors in a median period of 10 months (range 3-14 months). In conclusion, it seems that this transhepatic approach is safe and can be an alternative method for electrode insertion during RF ablation of selected renal tumors.

  8. Percutaneous Radiofrequency Ablation of a Small Renal Mass Complicated by Appendiceal Perforation

    SciTech Connect

    Boone, Judith; Bex, Axel; Prevoo, Warner

    2012-06-15

    Percutaneous radiofrequency ablation (RFA) has gained wide acceptance as nephron-sparing therapy for small renal masses in select patients. Generally, it is a safe procedure with minor morbidity and acceptable short-term oncologic outcome. However, as a result of the close proximity of vital structures, such as the bowel, ureter, and large vessels, to the ablative field, complications regarding these structures may occur. This is the first article describing appendiceal perforation as a complication of computed tomography-guided RFA despite hydrodissection. When performing this innovative and promising procedure one should be aware of the possibility of particular minor and even major complications.

  9. Percutaneous Radiofrequency Ablation for Treatment of Recurrent Retroperitoneal Liposarcoma

    SciTech Connect

    Keil, Sebastian Bruners, Philipp; Brehmer, Bernhard; Mahnken, Andreas Horst

    2008-07-15

    Percutaneous CT-guided radiofrequency ablation (RFA) is becoming more and more established in the treatment of various neoplasms, including retroperitoneal tumors of the kidneys and the adrenal glands. We report the case of RFA in a patient suffering from the third relapse of a retroperitoneal liposarcoma in the left psoas muscle. After repeated surgical resection and supportive radiation therapy of a primary retroperitoneal liposarcoma and two surgically treated recurrences, including replacement of the ureter by a fraction of the ileum, there was no option for further surgery. Thus, we considered RFA as the most suitable treatment option. Monopolar RFA was performed in a single session with a 2-cm umbrella-shaped LeVeen probe. During a 27-month follow-up period the patient remained free of tumor.

  10. Percutaneous treatment of bone tumors by radiofrequency thermal ablation.

    PubMed

    Ruiz Santiago, Fernando; Castellano García, María del Mar; Guzmán Álvarez, Luis; Martínez Montes, Jose Luis; Ruiz García, Manuel; Tristán Fernández, Juan Miguel

    2011-01-01

    We present our experience of the treatment of bone tumors with radiofrequency thermal ablation (RFTA). Over the past 4 years, we have treated 26 cases (22 benign and 4 malignant) using CT-guided RFTA. RFTA was the sole treatment in 19 cases and was combined with percutaneous cementation during the same session in the remaining seven cases. Our approach to the tumors was simplified, using a single point of entrance for both RFTA and percutaneous osteoplasty. In the benign cases, clinical success was defined as resolution of pain within 1 month of the procedure and no recurrence during the follow-up period. It was achieved in 19 out of the 21 patients in which curative treatment was attempted. The two non-resolved cases were a patient with osteoid osteoma who developed a symptomatic bone infarct after a symptom-free period of 2 months and another with femoral diaphysis osteoblastoma who suffered a pathological fracture after 8 months without symptoms. The procedure was considered clinically successful in the five cases (4 malign and 1 benign) in which palliative treatment was attempted, because there was a mean (±SD) reduction in visual analogue scale (VAS) pain score from 9.0±0.4 before the procedure to <4 during the follow-up period.

  11. Percutaneous bipolar radiofrequency T3 sympathicotomy in Raynaud's disease -A case report-.

    PubMed

    Kang, Sang-Soo; Park, Jung-Chan; Hong, Sung-Jun; Yoon, Young-Jun; Shin, Keun-Man

    2012-11-01

    A 54-year-old female was suffering from cold-induced Raynaud's attacks in her both hands with symptoms most severe in her left hand. As the patient did not respond to previous medical treatments and endoscopic thoracic sympathectomy, we performed percutaneous bipolar radiofrequency thoracic sympathicotomy at the left T3 vertebral level. After the procedure, the patient obtained a long duration of symptom relief over 3 years. Percutaneous bipolar radiofrequency T3 sympathicotomy is minimally invasive and effective technique by creating large continuous strip lesion.

  12. Treatment of osteoid osteoma with CT-guided percutaneous radiofrequency thermoablation.

    PubMed

    de Palma, Luigi; Candelari, Roberto; Antico, Ettore; Politano, Rocco; Luniew, Eugenio; Giordanengo, Maurizio; Di Giansante, Silvio; Marinelli, Mario; Paci, Enrico

    2013-05-01

    Osteoid osteoma is a benign bone tumor with a male predominance occurring mainly in children and young adults. The most common symptom is intermittent pain that worsens at night and is at least partially relieved by nonsteroidal anti-inflammatory drugs. The purpose of this study was to assess the long-term effectiveness of computed tomography-guided percutaneous radiofrequency thermoablation in patients with a minimum follow-up of 2 years. Twenty patients with osteoid osteoma (15 men and 5 women) with a mean age of 20.7 years (range, 4-61 years; 12 patients aged 20 years or younger) underwent computed tomography-guided percutaneous radiofrequency thermoablation. Lesion sites were the femur (n=9), tibia (n=7), pelvis (n=1), talus (n=1), cuneiform bone (n=1), and humerus (n=1). Mean follow-up was 44 months (range, 3-106 months). Pain relief was significant in 95% of patients; it disappeared within 24 hours in 14 patients, within 3 days in 4, and within 7 days in 1. The patient with persistent symptoms underwent another percutaneous radiofrequency thermoablation procedure that was successful. The difference between pre- and postoperative pain was significant (P ≤ .01). No recurrences occurred. Computed tomography-guided percutaneous radiofrequency thermoablation is a safe, minimally invasive, and economical procedure with high technical and clinical success rates, and it effectively and durably enhances quality of life.

  13. Is percutaneous radiofrequency coblation for treatment of Achilles tendinosis safe and effective?

    PubMed

    Shibuya, Naohiro; Thorud, Jakob C; Humphers, Jon M; Devall, J Marshall; Jupiter, Daniel C

    2012-01-01

    Insertional Achilles tendinosis results in isolated pain at the Achilles tendon insertion site due to intratendinous degeneration. When conservative measures fail, surgical treatment may be necessary. Radiofrequency coblation has been suggested to be an effective procedure for treatment of tendon pathologies. Percutaneous execution of this procedure is very simple as well as minimally invasive, and thus if effective, would be an excellent alternative to an open treatment of insertional Achilles tendinopathy. A review of 47 cases with this percutaneous technique was conducted. In our relatively short-term follow-up (mean = 8.6 months, SD = 9.71, range 1 to 40), the incidence of reoperation was 14.9% (7/47). Rupture of the Achilles tendon was identified in 3 (6.4%) patients. Our cohort had a relatively high body mass index (mean = 37.1, SD = 6.96, range 24.3 to 52.8). We recommend surgeons to be cautious about selecting this procedure in similar, high body mass index patient cohorts for treatment of Achilles tendinosis.

  14. Percutaneous lumbar sympathectomy: A comparison of radiofrequency denervation versus phenol neurolysis

    SciTech Connect

    Haynsworth, R.F. Jr.; Noe, C.E. )

    1991-03-01

    A new percutaneous approach to sympathectomy using radiofrequency denervation has seemed to offer longer duration and less incidence of postsympathetic neuralgia as compared to phenol sympathetic blocks. To compare these techniques, 17 patients underwent either phenol lumbar sympathetic blocks (n = 9) or radiofrequency denervation (n = 8). Duration of sympathetic block was followed by a sweat test and temperature measurements. Results indicate that 89% of patients in the phenol group showed signs of sympathetic blockade after 8 weeks, as compared to 12% in the radiofrequency group (P less than 0.05). Although the incidence of post sympathetic neuralgia appears to be less with radiofrequency denervation, further refinement of needle placement to ensure complete lesioning of the sympathetic chain will be required before the technique can offer advantages over current phenol techniques.

  15. Effect of percutaneous renal sympathetic nerve radiofrequency ablation in patients with severe heart failure.

    PubMed

    Dai, Qiming; Lu, Jing; Wang, Benwen; Ma, Genshan

    2015-01-01

    This study aimed to investigate the clinical feasibility and effects of percutaneous renal sympathetic nerve radiofrequency ablation in patients with heart failure. A total of 20 patients with heart failure were enrolled, aged from 47 to 75 years (63±10 years). They were divided into the standard therapy (n = 10), and renal nerve radiofrequency ablation groups (n = 10). There were 15 males and 5 female patients, including 8 ischemic cardiomyopathy, 8 dilated cardiomyopathy, and 8 hypertensive cardiopathy. All of the patients met the criteria of New York Heart Association classes III-IV cardiac function. Patients with diabetes and renal failure were excluded. Percutaneous renal sympathetic nerve radiofrequency ablation was performed on the renal artery wall under X-ray guidance. Serum electrolytes, neurohormones, and 24 h urine volume were recorded 24 h before and after the operation. Echocardiograms were performed to obtain left ventricular ejection fraction at baseline and 6 months. Heart rate, blood pressure, symptoms of dyspnea and edema were also monitored. After renal nerve ablation, 24 h urine volume was increased, while neurohormone levels were decreased compared with those of pre-operation and standard therapy. No obvious change in heart rate or blood pressure was recorded. Symptoms of heart failure were improved in patients after the operation. No complications were recorded in the study. Percutaneous renal sympathetic nerve radiofrequency ablation may be a feasible, safe, and effective treatment for the patients with severe congestive heart failure.

  16. Percutaneous radiofrequency rhizotomy of lumbar spinal facets: the results of 46 cases.

    PubMed

    Göçer, A I; Cetinalp, E; Tuna, M; Ildan, F; Bağdatoğlu, H; Haciyakupoğlu, S

    1997-01-01

    The results of percutaneous radiofrequency rhizotomy of lumbar spinal facets in 46 patients followed at least three months (mean 15 months) are reported and compared with those reported previously. Satisfactory pain relief three months after the procedure was achieved in 36.4 percent of patients without operations and in 41.7 percent of patients, with operations other than fusion. No patient had previously undergone fusion. Treatment of low-back pain by using radio-frequency thermocoagulation of spinal facets is a simple, safe, and well-tolerated procedure. It can be used to relief of pain in spite of decreasing rates of success within the follow-up period.

  17. Radiofrequency ablation or percutaneous ethanol injection for the treatment of liver tumors

    PubMed Central

    Ansari, Daniel; Andersson, Roland

    2012-01-01

    The liver is a common location of both primary and secondary malignancies. For unresectable liver cancer, many local ablative therapies have been developed. These include e.g., percutaneous ethanol injection (PEI), percutaneous acetic acid injection, radiofrequency ablation (RFA), cryoablation, microwave ablation, laser-induced thermotherapy, and high-intensity focused ultrasound. RFA has recently gained interest and is the most widely applied thermoablative technique. RFA allows more effective tumor control in fewer treatment sessions compared with PEI, but with a higher rate of complications. However, there are certain circumstances where PEI therapy represents a better strategy to control liver tumors than RFA, especially in situations where RFA is difficult, for example when large vessels surround the tumor. In the context of hepatocellular carcinoma (HCC), both RFA and PEI are feasible and of benefit in non-operable patients. RFA seems superior to PEI in HCC > 2 cm, and the combination of interventions may be of benefit in selected patients. Liver resection is superior to RFA for patients with HCC meeting the Milan criteria, but RFA can be employed in tumors ≤ 3 cm and where there is an increased expected operative mortality. In addition, some lines of evidence indicate that RFA and PEI can be employed as a bridge to liver transplantation. The use of RFA in colorectal liver metastases is currently limited to unresectable disease and for patients unfit for surgery. The aim of this article is to summarize the current status of RFA in the management of liver tumors and compare it to the cheap and readily available technique of PEI. PMID:22416173

  18. Percutaneous radiofrequency facet capsule denervation as an alternative target in lumbar facet syndrome.

    PubMed

    Moussa, Wael Mohamed Mohamed; Khedr, Wael

    2016-11-01

    Percutaneous radiofrequency denervation of the medial dorsal branch is often used in chronic low back pain of intervertebral facet etiology, which is sometimes difficult to perform and recurrence of pain often ensues. We theorized that shifting the target of RF coagulation to the facet joint capsule would provide an easier target and a longer-lived pain relieving response. A prospective randomized controlled trial where 120 patients diagnosed with CLBP of a confirmed facet origin were randomly divided into three equal groups, the first was submitted to percutaneous radiofrequency coagulation of the facet joint capsule, the second underwent percuataneous denervation of the medial dorsal branch and the third did not receive radiofrequency lesioning. All the three groups received local injection of a mixture of local anesthetic and steroid. Cases were followed for up to 3 years. 87(72.5%) patients were females. By 3 months' post procedure, improvement in VAS was significantly better than pretreatment levels in all groups (p<0.05). The control group lost improvement by 1-year follow-up (p=0.017). At 2 years' follow-up, the joint capsule denervation group maintained significant improvement (p=0.033) whereas the medial branch denervation group lost its significant effect (p=0.479). By the end of follow-up period, only joint capsule denervation group kept significant improvement (p=0.026). In CLBP of facet origin, shifting the target of percutaneous radiofrequency to the facet joint capsule provides an easier technique with an extended period of pain relief compared to the medial dorsal branch of the facet joint. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Percutaneous ultrasound-guided radiofrequency thermal ablation of malignant osteolyses.

    PubMed

    Poggi, Guido; Gatti, Carlo; Melazzini, Mario; Bernardo, Giovanni; Strada, Mariarosa; Teragni, Cristina; Delmonte, Angelo; Tagliaferri, Carlo; Bonezzi, Cesare; Barbieri, Massimo; Bernardo, Antonio; Fratino, Pietro

    2003-01-01

    Metastases are the most common neoplastic pathology involving the skeletal system. The hallmark of skeletal metastases is pain that often compromises the patient's quality of life. Radiotherapy, surgery and chemotherapy are the cornerstones of the treatment, but these techniques are not completely effective. Radiofrequency thermal ablation (RFA) may offer an alternative to conventional therapies for pain control. At present, the main field of application of RFA is the treatment of primary or secondary tumors of the liver but, recently, the technique has been effectively used to treat various other tumors in organs such as the prostate, kidney, lung, brain, pancreas and breast and to control pain caused by osteoid osteomas. Five patients with six painful bone metastases underwent RFA. The patients were three women and two men, aged 40-77 years (mean: 63.4). The radiofrequency system consists of an insulated 18-gauge needle electrode attached to a 500-kHz RF generator (Radionics, Burlington, Mass, USA). Four of our five patients rapidly obtained pain relief. One patient was completely pain free within 48 hours of the procedure and the control of pain persisted for 88 weeks. Another three patients obtained at least fifty percent pain reduction that lasted, on average, 12 weeks. Our preliminary results confirm that ultrasound-guided RFA is a simple and safe technique for treating painful superficial bone metastases.

  20. Percutaneous Intraductal Radiofrequency Ablation is a Safe Treatment for Malignant Biliary Obstruction: Feasibility and Early Results

    SciTech Connect

    Mizandari, Malkhaz; Pai, Madhava Xi Feng; Valek, Vlastimil; Tomas, Andrasina; Quaretti, Pietro; Golfieri, Rita; Mosconi, Cristina; Ao Guokun; Kyriakides, Charis; Dickinson, Robert; Nicholls, Joanna; Habib, Nagy

    2013-06-15

    Purpose. Previous clinical studies have shown the safety and efficacy of this novel radiofrequency ablation catheter when used for endoscopic palliative procedures. We report a retrospective study with the results of first in man percutaneous intraductal radiofrequency ablation in patients with malignant biliary obstruction. Methods. Thirty-nine patients with inoperable malignant biliary obstruction were included. These patients underwent intraductal biliary radiofrequency ablation of their malignant biliary strictures following external biliary decompression with an internal-external biliary drainage. Following ablation, they had a metal stent inserted. Results. Following this intervention, there were no 30-day mortality, hemorrhage, bile duct perforation, bile leak, or pancreatitis. Of the 39 patients, 28 are alive and 10 patients are dead with a median survival of 89.5 (range 14-260) days and median stent patency of 84.5 (range 14-260) days. One patient was lost to follow-up. All but one patient had their stent patent at the time of last follow-up or death. One patient with stent blockage at 42 days postprocedure underwent percutaneous transhepatic drain insertion and restenting. Among the patients who are alive (n = 28) the median stent patency was 92 (range 14-260) days, whereas the patients who died (n = 10) had a median stent patency of 62.5 (range 38-210) days. Conclusions. In this group of patients, it appears that this new approach is feasible and safe. Efficacy remains to be proven in future, randomized, prospective studies.

  1. Novel Percutaneous Radiofrequency Ablation of Portal Vein Tumor Thrombus: Safety and Feasibility

    SciTech Connect

    Mizandari, Malkhaz; Ao, Guokun; Zhang Yaojun; Feng Xi; Shen Qiang; Chen Minshan; Lau, Wan Yee; Nicholls, Joanna; Jiao Long; Habib, Nagy

    2013-02-15

    We report our experience of the safety of partial recanalization of the portal vein using a novel endovascular radiofrequency (RF) catheter for portal vein tumor thrombosis. Six patients with liver cancer and tumor thrombus in the portal vein underwent percutaneous intravascular radiofrequency ablation (RFA) using an endovascular bipolar RF device. A 0.035-inch guidewire was introduced into a tributary of the portal vein and through which a 5G guide catheter was introduced into the main portal vein. After manipulation of the guide catheter over the thrombus under digital subtraction angiography, the endovascular RF device was inserted and activated around the thrombus. There were no observed technique specific complications, such as hemorrhage, vessel perforation, or infection. Post-RFA portography showed partial recanalization of portal vein. RFA of portal vein tumor thrombus in patients with hepatocellular carcinoma is technically feasible and warrants further investigation to assess efficacy compared with current recanalization techniques.

  2. Usefulness of CT During Renal Arteriography: A Case of Percutaneous Radiofrequency Ablation for Renal Cell Carcinoma

    SciTech Connect

    Tanigawa, Noboru Kariya, Shuji; Komemushi, Atsushi; Kojima, Hiroyuki; Sawada, Satoshi

    2004-11-15

    A 64-year-old man with a unilateral 15 mm diameter renal cell carcinoma underwent percutaneous radiofrequency ablation (RFA) assisted by CT during renal arteriography (angio-CT). Prior to placement of the needle electrode, a 5 Fr angio-catheter was placed in the right renal artery, and angio-CT was performed before, during and after the procedure. Since multiple angio-CT can be performed using a small amount of diluted contrast agent, RFA can be monitored without impairing renal function. As a result, this imaging combination was found to be useful for determining the end point of ablation.

  3. A case of biliary gastric fistula following percutaneous radiofrequency thermal ablation of hepatocellular carcinoma

    PubMed Central

    Falco, Angela; Orlando, Dante; Sciarra, Roberto; Sergiacomo, Luciano

    2007-01-01

    Percutaneous radiofrequency thermal ablation (RFA) is an effective and safe therapeutic modality in the management of liver malignancies, performed with ultrasound guidance. Potential complications of RFA include liver abscess, ascites, pleural effusion, skin burn, hypoxemia, pneumothorax, subcapsular hematoma, hemoperitoneum, liver failure, tumour seeding, biliary lesions. Here we describe for the first time a case of biliary gastric fistula occurred in a 66-year old man with a Child’s class A alcoholic liver cirrhosis as a complication of RFA of a large hepatocellular carcinoma lesion in the III segment. In the light of this case, RFA with injection of saline between the liver and adjacent gastrointestinal tract, as well as laparoscopic RFA, ethanol injection (PEI), or other techniques such as chemoembolization, appear to be more indicated than percutaneous RFA for large lesions close to the gastrointestinal tract. PMID:17278208

  4. In vivo intracardiac OCT imaging through percutaneous access: towards image guided radio-frequency ablation

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Kang, Wei; Carrigan, Thomas; Bishop, Austin; Rosenthal, Noah; Arruda, Mauricio; Rollins, Andrew M.

    2012-01-01

    BACKGROUND Complete catheter-tissue contact and permanent tissue destruction are essential for efficient radio-frequency ablation (RFA) during cardiac arrhythmia treatment. Current methods of monitoring lesion formation are indirect and unreliable. We aim to develop optical coherence tomography (OCT) as an imaging guidance for RFA. OBJECTIVES The purpose of this study is to evaluate the feasibility of using OCT catheter to image endocardia wall in active beating hearts through percutaneous access. This is a critical step toward image guided RFA in a clinic setting. METHODS A cone-scanning forward-viewing OCT catheter was advanced into active beating hearts through percutaneous access in four swine. The OCT catheter was steered by an introducer to touch the endocardia wall. The images were then acquired at 10 frames per second at an axial resolution and lateral resolution of 15 μm. RESULTS We report the first in vivo intracardiac OCT imaging through percutaneous access with a thin and flexible OCT catheter. We are able to acquire high quality OCT images in active beating hearts, observe the polarization-related artifacts induced by the birefringence of myocardium and readily evaluate catheter-tissue contact. CONCLUSIONS It is feasible to acquire OCT images in beating hearts through percutaneous access. The observations indicate that OCT could be a promising technique for in vivo guidance of RFA.

  5. Percutaneous radiofrequency thermal ablation of hepatocellular carcinoma: a safe and effective bridge to liver transplantation.

    PubMed

    Fontana, Robert J; Hamidullah, Halimi; Nghiem, Hanh; Greenson, Joel K; Hussain, Hero; Marrero, Jorge; Rudich, Steve; McClure, Leslie A; Arenas, Juan

    2002-12-01

    The incidence of hepatocellular carcinoma (HCC) is increasing in the United States. Although liver transplantation is an effective means of treating selected patients, pretransplantation tumor progression may preclude some patients from undergoing transplantation. The aim of this study is to determine the safety and efficacy of percutaneous radiofrequency thermal ablation (RFA) in 33 consecutive patients with nonresectable HCC and advanced cirrhosis. Mean subject age was 57.2 +/- 10.6 years, mean Child-Turcotte-Pugh score was 7.0 +/- 1.4, and mean maximal tumor diameter was 3.6 +/- 1.1 cm. Using contrast-enhanced computed tomography and magnetic resonance imaging, 22 patients (66%) had a complete radiological response at 3 months post-RFA, whereas 11 patients (33%) had an incomplete radiological response. During follow-up, 18 patients (54%) experienced tumor progression and 9 subjects underwent repeated ablation for either residual disease or tumor progression. The overall actuarial patient survival rate of the 33 patients was 58% at 2 years, whereas the transplantation-free patient survival rate was 34% at 2 years. Fifteen of 23 transplant candidates were successfully bridged to liver transplantation after a mean post-RFA follow-up of 7.9 +/- 6.7 months. The extent of tumor necrosis in the explant varied, but no subjects had evidence of tumor seeding on post-RFA imaging, at liver transplantation, or in the explant. The 3-year actuarial posttransplantation patient survival rate was 85%. Two patients have developed posttransplantation recurrence, and both had microscopic vascular invasion in their explants. In summary, our data show that RFA is a safe and effective treatment modality for patients with advanced cirrhosis and nonresectable HCC. Although the ability of RFA to prevent or delay tumor progression requires further prospective study, its favorable safety profile and promising efficacy make it an attractive treatment option for liver transplant candidates

  6. Percutaneous intraductal radiofrequency ablation for treatment of biliary stent occlusion: A preliminary result

    PubMed Central

    Xia, Ning; Gong, Ju; Lu, Jian; Chen, Zhi-Jin; Zhang, Li-Yun; Wang, Zhong-Min

    2017-01-01

    AIM To assess the feasibility and effectiveness of a novel application of percutaneous intraductal radiofrequency (RF) for the treatment of biliary stent obstruction. METHODS We specifically report a retrospective study presenting the results of percutaneous intraductal RF in patients with biliary stent occlusion. A total of 43 cases involving biliary stent obstruction were treated by placing an EndoHPB catheter and percutaneous intraductal RF was performed to clean stents. The stent patency was evaluated by cholangiography and follow-up by contrast enhanced computed tomography or ultrasound after the removal of the drainage catheter. RESULTS Following the procedures, of the 43 patients, 40 survived and 3 died with a median survival of 80.5 (range: 30-243) d. One patient was lost to follow-up. One patient had the stent patent at the time of last follow-up. Two patients with stent blockage at 35 d and 44 d after procedure underwent percutaneous transhepatic drain insertion only. The levels of bilirubin before and after the procedure were 128 ± 65 μmol/L and 63 ± 29 μmol/L, respectively. There were no related complications (haemorrhage, bile duct perforation, bile leak or pancreatitis) and all patients’ stent patency was confirmed by cholangiography after the procedure, with a median patency time of 107 (range: 12-180) d. CONCLUSION This preliminary clinical study demonstrated that percutaneous intraductal RF is safe and effective for the treatment of biliary stent obstruction, increasing the duration of stent patency, although randomized controlled trials are needed to confirm the effectiveness of this approach. PMID:28348491

  7. Percutaneous Radiofrequency Lung Ablation Combined with Transbronchial Saline Injection: An Experimental Study in Swine

    SciTech Connect

    Kawai, T. Kaminou, T. Sugiura, K.; Hashimoto, M.; Ohuchi, Y.; Adachi, A.; Fujioka, S.; Ito, H.; Nakamura, K.; Ihaya, T.; Ogawa, T.

    2010-02-15

    To evaluate the efficacy of radiofrequency lung ablation with transbronchial saline injection. The bilateral lungs of eight living swine were used. A 13-gauge bone biopsy needle was inserted percutaneously into the lung, and 1 ml of muscle paste was injected to create a tumor mimic. In total, 21 nodules were ablated. In the saline injection group (group A), radiofrequency ablation (RFA) was performed for 11 nodules after transbronchial saline injection under balloon occlusion with a 2-cm active single internally cooled electrode. In the control group (group B), conventional RFA was performed for 10 nodules as a control. The infused saline liquid showed a wedge-shaped and homogeneous distribution surrounding a tumor mimic. All 21 RFAs were successfully completed. The total ablation time was significantly longer (13.4 {+-} 2.8 min vs. 8.9 {+-} 3.5 min; P = 0.0061) and the tissue impedance was significantly lower in group A compared with group B (73.1 {+-} 8.8 {Omega} vs. 100.6 {+-} 16.6 {Omega}; P = 0.0002). The temperature of the ablated area was not significantly different (69.4 {+-} 9.1{sup o}C vs. 66.0 {+-} 7.9{sup o}C; P = 0.4038). There was no significant difference of tumor mimic volume (769 {+-} 343 mm{sup 3} vs. 625 {+-} 191 mm{sup 3}; P = 0.2783). The volume of the coagulated area was significantly larger in group A than in group B (3886 {+-} 1247 mm{sup 3} vs. 2375 {+-} 1395 mm{sup 3}; P = 0.0221). Percutaneous radiofrequency lung ablation combined with transbronchial saline injection can create an extended area of ablation.

  8. Biliary tract perforation following percutaneous endobiliary radiofrequency ablation: A report of two cases

    PubMed Central

    ZHOU, CHUANGUO; WEI, BAOJIE; GAO, KUN; ZHAI, RENYOU

    2016-01-01

    Endobiliary radiofrequency ablation (RFA) has recently been recognized as a beneficial treatment option for malignant biliary obstruction using percutaneous or endoscopic approaches. The feasibility and safety of this method has been demonstrated in clinical studies, with pain, cholangitis and asymptomatic biochemical pancreatitis reported as relatively common complications. By contrast, hepatic coma, newly diagnosed left bundle branch block and partial liver infarction have been reported as uncommon complications. Biliary tract perforation is a serious potential complication of percutaneous intraductal RFA, which may result in severe infection, peritonitis or even mortality, and which has not been previously reported in clinical research. The current study presents the first reports of biliary tract perforation in two patients with unresectable malignant biliary obstruction following percutaneous intraductal RFA. Although the patient in case 1 succumbed 12 days after RFA, the minor biliary tract perforation in case 2 was successfully treated by the deployment of a self-expanding metal stent. This study demonstrates that biliary tract perforation should be recognized as a serious potential complication of endobiliary RFA, and that metal stent deployment should be considered as a treatment option for minor biliary tract perforation. PMID:27313699

  9. Percutaneous Intraductal Radiofrequency Ablation for Clearance of Occluded Metal Stent in Malignant Biliary Obstruction: Feasibility and Early Results

    SciTech Connect

    Pai, Madhava; Valek, Vlastimil; Tomas, Andrasina; Doros, Attila; Quaretti, Pietro; Golfieri, Rita; Mosconi, Cristina; Habib, Nagy

    2013-07-11

    PurposeThe major complication occurring with biliary stents is stent occlusion, frequently seen because of tumour in-growth, epithelial hyperplasia, and sludge deposits, resulting in recurrent jaundice and cholangitis. We report a prospective study with the results of first in man percutaneous intraductal radiofrequency (RF) ablation to clear the blocked metal stents in patients with malignant biliary obstruction using a novel bipolar RF catheter.MethodsNine patients with malignant biliary obstruction and blocked metal stents were included. These patients underwent intraductal biliary RF ablation through the blocked metal stent following external biliary decompression with an internal–external biliary drainage.ResultsAll nine patients had their stent patency restored successfully without the use of secondary stents. Following this intervention, there was no 30-day mortality, haemorrhage, bile duct perforation, bile leak, or pancreatitis. Of the nine patients, six are alive and three patients are dead with a median follow-up of 122 (range 50–488) days and a median stent patency of 102.5 (range 50–321) days. Six patients had their stent patent at the time of last follow-up or death. Three patients with stent blockage at 321, 290, and 65 days postprocedure underwent percutaneous transhepatic drain insertion and repeat ablation.ConclusionsIn this selective group of patients, it appears that this new approach is safe and feasible. Efficacy remains to be proven in future, randomized, prospective studies.

  10. Management of pain on hallux valgus with percutaneous intra-articular Pulse-Dose Radiofrequency.

    PubMed

    Masala, Salvatore; Fiori, Roberto; Calabria, Eros; Raguso, Mario; de Vivo, Dominique; Cuzzolino, Alessandro; Simonetti, Giovanni

    2017-01-01

    The purpose of our study was to investigate the role of intra-articular pulse-dose radiofrequency in management of painful hallux valgus refractory to conservative therapies. Between November 2010 and April 2012, 51 patients (15 male, 36 female) with a median age of 71.4 years were included in our clinical trial. Under fluoroscopic guidance we introduced a 22 gauge 10 cm length cannula by a percutaneous access in the first metatarsophalangeal joint and its tip was placed intra-articularly. After removing the spindle, a radiofrequency needle with a 5 mm active tip was introduced. The following parameters were used: 1200 pulses at high voltage (45 V) with 20 msec duration followed by 480 msec silent phases. A great reduction in pain intensity was documented at 1 week, 1 month and 3 months after procedures. Pain intensity increased between 5 and 8 months after treatments, so we performed a second procedure in all patients between 7 months and 9 months since the first treatment. Also in this case we obtained a great reduction of pain intensity in the first 3 months after the procedure. Pain intensity returned at preprocedural values after 9 months after second procedure. No complications were observed. Our experience shows pulse-dose radiofrequency is a safe, repeatable and effective technique for managing patients with symptomatic hallux valgus in the short and medium term. Pulse-dose radiofrequency may improve pain control and quality of life in patients with hallux valgus refractory to conservative therapies. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  11. Process for selected gas oxide removal by radiofrequency catalysts

    DOEpatents

    Cha, Chang Y.

    1993-01-01

    This process to remove gas oxides from flue gas utilizes adsorption on a char bed subsequently followed by radiofrequency catalysis enhancing such removal through selected reactions. Common gas oxides include SO.sub.2 and NO.sub.x.

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

    PubMed Central

    Dong, Jun; Li, Wang; Zeng, Qi; Li, Sheng; Gong, Xiao; Shen, Lujun; Mao, Siyue; Dong, Annan; Wu, Peihong

    2015-01-01

    Abstract 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. PMID:26426638

  13. [Hepatocellular carcinoma: percutaneous ethanol injection/transarterial chemoembolization/radiofrequency thermoablation].

    PubMed

    Allgaier, H P; Rossi, S; Deibert, P; Zuber, I; Hering, M; Blum, H E

    2000-06-15

    In the majority of patients hepatocellular carcinoma (HCC) is associated with liver cirrhosis. Advanced or decompensated liver cirrhosis, comorbidity and multicentricity make 70-80% of HCCs inoperable at the time of diagnosis. Therefore, percutaneous ethanol injection (PEI) and radiofrequency thermal ablation (RFTA) are non-surgical therapeutic options for patients with small HCCs. In patients with advanced tumor stage transarterial chemoembolization (TACE) and its variants showed no survival benefit on the basis of randomized trials. In several studies, however, combined treatment strategies like TACE and PEI or RFTA after occlusion of tumor blood supply in the treatment of advanced HCC seems to result in a survival benefit. All HCC patients should be included in randomized treatment studies.

  14. Comparison of nerve combing and percutaneous radiofrequency thermocoagulation in the treatment for idiopathic trigeminal neuralgia.

    PubMed

    Zhou, Xuanchen; Liu, Yiqing; Yue, Zhiyong; Luan, Deheng; Zhang, Hong; Han, Jie

    2016-01-01

    Idiopathic trigeminal neuralgia (ITN) is a common pain disease in elderly people. Many methods have been used to alleviate the pain of patients, but few studies in the literature have compared the effect of nerve combing and percutaneous radiofrequency thermocoagulation. The purpose of this study was to describe and evaluate the clinical outcome of idiopathic trigeminal neuralgia after nerve combing (NC) and compare them with those obtained using percutaneous radiofrequency thermocoagulation (RF). The study included 105 idiopathic trigeminal neuralgia patients with similar symptom, age and underlying disease, which were divided into two groups. One group was treated by nerve combing (50 patients), the other by RF (55 cases). All patients were considered medical failures prior to the surgeries. A questionnaire was used to assess the long-term outcomes: pain relief, recurrence, complication and need for additional treatment. The median duration of follow-up in both groups was 90 months. Satisfactory relief was noted in 41 patients (82%), 5 patients (10%) initially experienced pain relief, then recurred, and four patients (8%) were designated poor among the group NC. In the group RF, satisfactory relief was noted in 42 patients (76.4%). There were eight "pain free with recurrence patients (14.5%) and 5 poor cases (9.1%). No statistically significant differences existed in the outcomes between both groups (p>0.05). Postoperative morbidity included dysesthesia, diplopia, partial facial nerve palsy, hearing loss, tinnitus, cerebrospinal fluid leak, meningitis and mortality. Nerve combing and RF are both satisfactory treatment strategies for patients with ITN. Because of the higher risk of sensory morbidity and surgical risk as open surgery, RF is preferred as the recommended procedure for patients with ITN. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  15. Percutaneous ultrasound-guided radiofrequency heat ablation for treatment of hyperthyroidism in cats.

    PubMed

    Mallery, Kevin F; Pollard, Rachel E; Nelson, Richard W; Hornof, William J; Feldman, Edward C

    2003-12-01

    To determine efficacy and safety of percutaneous radiofrequency heat ablation for treatment of hyperthyroidism in cats. Prospective study. 9 cats. Hyperthyroidism was diagnosed via clinical signs and high serum total (TT4) and free thyroxine (fT4) concentrations. One or 2 hyperfunctional cervical thyroid nodules were detected by use of scintigraphy and ultrasonography. If cats had 1 abnormal thyroid lobe, heat ablation was performed on that lobe; if cats had 2 abnormal lobes, heat ablation was applied to the larger lobe. Overall, heat ablation was performed 14 times in the 9 cats. Clinical signs and serum TT4, fT4, and calcium concentrations were monitored daily for 2 days after the procedure, weekly for the first month, and then monthly. Laryngeal function was evaluated and cervical ultrasonography and thyroid scintigraphy were also performed. Monitoring continued for as long as 9 months after heat ablation if a cat became euthyroid or until an owner chose an alternative treatment because of recurrence of hyperthyroidism. Serum TT4 and fT4 concentrations transiently decreased after all 14 heat ablation procedures (< or = reference range after 10 of 14 treatments) within 2 days after the procedure. Cats were euthyroid for 0 to 18 months (mean, 4 months). Hyperthyroidism recurred in all cats. Adverse effects included transient Horner's syndrome (2 cats) and laryngeal paralysis without clinical signs (1 cat). Percutaneous heat ablation as a treatment for hyperthyroidism in cats is effective transiently but not permanently.

  16. Local ablative therapies in HCC: percutaneous ethanol injection and radiofrequency ablation.

    PubMed

    Mahnken, Andreas H; Bruners, Philipp; Günther, Rolf W

    2009-01-01

    Hepatocellular carcinoma (HCC) is the most common primary hepatic malignancy. Surgery and transarterial chemoembolization have for many years dominated the local treatment of HCC. The introduction of image-guided percutaneous techniques for local tumor ablation changed the treatment of liver cancer. Percutaneous ethanol injection (PEI) and radiofrequency ablation (RFA) have both successfully been employed in the treatment of HCC. In current guidelines both techniques are recommended as standard therapy in limited liver cancer. From the current literature both techniques have to be considered safe and effective in the treatment of HCC. Several randomized trials showed RFA to be superior to PEI for treating small HCC. Moreover, several studies analyzed survival after PEI or RFA in comparison with surgery, proving interventional therapy to be a serious competitor of resection. With introduction of combined interventional therapies including transarterial chemoembolization, PEI and RFA survival was improved further. In this article, we provide an insight into the technical basics of PEI and RFA and review the clinical results and indications of these interventional techniques in the treatment of HCC.

  17. Ultrasonography-guided percutaneous radiofrequency ablation for cervical lymph node metastasis from thyroid carcinoma.

    PubMed

    Wang, Liping; Ge, Minghua; Xu, Dong; Chen, Liyu; Qian, Chaowen; Shi, Kaiyuan; Liu, Junping; Chen, Yong

    2014-11-01

    The aim was to explore the efficacy and safety of ultrasonography-guided percutaneous radiofrequency ablation (RFA) for cervical lymph node metastases from thyroid carcinoma. Eight patients with previous total thyroidectomy and radioiodine therapy were enrolled in this study. A total of 20 cervical lymph node metastases were confirmed by percutaneous biopsy. Participants underwent ultrasonography-guided RFA treatment for all confirmed metastatic lymph nodes. Contrast-enhanced ultrasound (CEUS) and sonoelastography were performed to rapidly evaluate treatment responses before and shortly after RFA. Routine follow-up consisted of conventional US, CEUS, sonoelastography, thyroglobulin level, and necessary fine needle aspiration cytology. All eight patients were successfully treated without obvious complications. Post-RFA CEUS showed that total metastatic lymph nodes were ablated. The sonoelastographic score of ablated area elevated significantly shortly after RFA (P < 0.001). With a mean follow-up of 9.4 ± 5.1 months, there were no evidences of recurrence at ablated sites; however, two new cervical recurrent lymph nodes occurred in one case, which was successfully ablated as well. The mass volume shrinkages of the ablated nodes were observed in all cases. We found that 5 treated lymph nodes disappeared, 4 were reduced more than 80%, 9 were reduced between 50% and 80%, and 2 were reduced less than 50%. At the last follow-up evaluation, the serum thyroglobulin levels had decreased in 6 of 8 patients. Ultrasonography-guided percutaneous RFA for cervical lymph node metastasis of thyroid malignancy is a feasible, effective, and safe therapy. This procedure shows a nonsurgical therapeutic option for metastatic lymph nodes in patients with difficult reoperations or inoperations, it may reduce or delay a large number of highly invasive repeated neck dissections.

  18. Efficacy and survival analysis of percutaneous radiofrequency versus microwave ablation for hepatocellular carcinoma: an Egyptian multidisciplinary clinic experience.

    PubMed

    Abdelaziz, Ashraf; Elbaz, Tamer; Shousha, Hend Ibrahim; Mahmoud, Sherif; Ibrahim, Mostafa; Abdelmaksoud, Ahmed; Nabeel, Mohamed

    2014-12-01

    Hepatocellular carcinoma (HCC) is a primary tumor of the liver with poor prognosis. For early stage HCC, treatment options include surgical resection, liver transplantation, and percutaneous ablation. Percutaneous ablative techniques (radiofrequency and microwave techniques) emerged as best therapeutic options for nonsurgical patients. We aimed to determine the safety and efficacy of radiofrequency and microwave procedures for ablation of early stage HCC lesions and prospectively follow up our patients for survival analysis. One Hundred and 11 patients with early HCC are managed in our multidisciplinary clinic using either radiofrequency or microwave ablation. Patients are assessed for efficacy and safety. Complete ablation rate, local recurrence, and overall survival analysis are compared between both procedures. Radiofrequency ablation group (n = 45) and microwave ablation group (n = 66) were nearly comparable as regards the tumor and patients characteristics. Complete ablation was achieved in 94.2 and 96.1% of patients managed by radiofrequency and microwave ablation techniques, respectively (p value 0.6) with a low rate of minor complications (11.1 and 3.2, respectively) including subcapsular hematoma, thigh burn, abdominal wall skin burn, and pleural effusion. Ablation rates did not differ between ablated lesions ≤ 3 and 3-5 cm. A lower incidence of local recurrence was observed in microwave group (3.9 vs. 13.5% in radiofrequency group, p value 0.04). No difference between both groups as regards de novo lesions, portal vein thrombosis, and abdominal lymphadenopathy. The overall actuarial probability of survival was 91.6% at 1 year and 86.1% at 2 years with a higher survival rates noticed in microwave group but still without significant difference (p value 0.49). Radiofrequency and microwave ablations led to safe and equivalent ablation and survival rates (with superiority for microwave ablation as regards the incidence of local recurrence).

  19. Randomised controlled trial comparing percutaneous radiofrequency thermal ablation, percutaneous ethanol injection, and percutaneous acetic acid injection to treat hepatocellular carcinoma of 3 cm or less

    PubMed Central

    Lin, S-M; Lin, C-J; Lin, C-C; Hsu, C-W; Chen, Y-C

    2005-01-01

    Aims: The aim of this study was to compare the outcomes of radiofrequency thermal ablation (RFTA), percutaneous ethanol injection (PEI), and percutaneous acetic acid injection (PAI) in the treatment of hepatocellular carcinoma (HCC). Patients and methods: A total of 187 patients with HCCs of 3 cm or less were randomly assigned to RFTA (n = 62), PEI (n = 62), or PAI (n = 63). Tumour recurrence and survival rates were assessed. Results: One, two, and three year local recurrence rates were 10%, 14%, and 14% in the RFTA group, 16%, 34%, and 34% in the PEI group, and 14%, 31%, and 31% in the PAI group (RFTA v PEI, p = 0.012; RFTA v PAI, p = 0.017). One, two, and three year survival rates were 93%, 81%, and 74% in the RFTA group, 88%, 66%, and 51% in the PEI group, and 90%, 67%, and 53% in the PAI group (RFTA v PEI, p = 0.031; RFTA v PAI, p = 0.038). One, two, and three year cancer free survival rates were 74%, 60%, and 43% in the RFTA group, 70%, 41%, and 21% in the PEI group, and 71%, 43%, and 23% in the PAI group (RFTA v PEI, p = 0.038; RFTA v PAI, p = 0.041). Tumour size, tumour differentiation, and treatment methods (RFTA v PEI and PAI) were significant factors for local recurrence, overall survival, and cancer free survival. Major complications occurred in 4.8% of patients (two with haemothorax, one gastric perforation) in the RFTA group and in none in two other groups (RFTA v PEI and PAI, p = 0.035). Conclusions: RFTA was superior to PEI and PAI with respect to local recurrence, overall survival, and cancer free survival rates, but RFTA also caused more major complications. PMID:16009687

  20. Percutaneous radiofrequency ablation of renal tumors in high-risk patients: 10 years' experience.

    PubMed

    Alguersuari, A; Mateos, A; Falcó, J; Criado, E; Fortuño, J R; Guitart, J

    2016-01-01

    To retrospectively evaluate the efficacy and safety of percutaneous radiofrequency ablation (RFA) done to treat renal tumors in patients with high surgical risk or with the risk of developing multiple renal tumors in the medium term at our center over a period of 10 years. Between 2005 and 2015, we used RFA to treat 89 T1a or T1b tumors in 87 patients (mean age, 73.7±10.87 years) with high surgical risk. We excluded patients treated with radiofrequency and embolization or microwave ablation. The tumors treated were clear cell carcinomas (43.6%), papillary renal carcinomas (17.2%), chromophobe renal cell carcinomas (10.3%), cystic tumors (2.2%), and an angiomyolipoma (1.1%). The mean size of the tumors was 2.6cm. Computed tomography and/or ultrasonography were used to guide the procedure. We analyzed the relation between the efficacy of the procedure and patients' age, the type of needle, the source of the patients, the size and location of the tumor, and the number of sessions required to achieve ablation. We recorded all complications. The RFA procedure was completed in all patients. The mean follow-up period was 32.1 months. The efficacy was 93.7%. A single session was sufficient in 87.5% of patients; 8% required two sessions and 4.5% required three sessions. The only factor associated with worse efficacy was the size of the tumor (p=0.03). The rate of complications was 5.6%. RFA is efficacious and safe, with results comparable to those reported in the literature. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Evaluation of the safety and efficacy of percutaneous radiofrequency ablation for treating multiple breast fibroadenoma.

    PubMed

    Li, Ping; Xiao-Yin, Tang; Cui, Dan; Chi, Jia-Chang; Wang, Zhi; Wang, Tao; Qi, Xing-Xing; Zhai, Bo

    2016-12-01

    This study was conducted to evaluate the safety and efficacy of ultrasound (US)-guided percutaneous radiofrequency ablation (RFA) for multiple breast fibroadenoma as an alternative to surgical resection. Sixty-five patients with multiple breast fibroadenoma accepted general anesthesia and US-guided percutaneous RFA in our hospital from September 2014 to January 2016. Contrast-enhanced US (CEUS) was used immediately after operation to determine whether the tumor was ablated completely. The complete ablation rate (CAR) and the change of focal volume were evaluated by CEUS at the 1st month and the 3rd month after operation. All the patients were diagnosed by needle biopsy. Among all the patients, 256 nodules were found. Forty-six nodules (17.96%) were located <5 mm from epidermis; 26 nodules (10.15%) were located below areola. Complete ablation was achieved for 251 nodules (98.04%) after the 1st month of operation. The volume reduce rate was 39.06% and 75.99% at the 1st and the 3rd month after operation, respectively, of which 45 nodules were completely absorbed (17.58%). There was a statistically significant difference of the volume reduction rate (VRR) after operation (P < 0.01) compared with preoperative breast nodules volume. There were no complications such as skin burn, hemorrhage, and hematoma, nipple discharge in the process during and after RFA. Given advantages of high CAR, mild injury, rapid recovery, and cosmetic outcome desired by the patients, RFA has the potential to become the preferred method in the treatment of breast fibroadenoma.

  2. Treatment efficacy and safety of ultrasound-guided percutaneous bipolar radiofrequency ablation for benign thyroid nodules

    PubMed Central

    Li, Xiao-long; Lu, Feng; Yue, Wen-wen; Sun, Li-ping; Bo, Xiao-wan; Guo, Le-hang; Xu, Jun-mei; Liu, Bo-ji; Li, Dan-dan; Qu, Shen

    2016-01-01

    Objective: To evaluate the therapeutic efficacy and safety of ultrasound-guided percutaneous bipolar radiofrequency ablation (BRFA) of benign thyroid nodules by comparison with a matched untreated control group. Methods: The therapeutic efficacy and safety in 35 patients who were subjected to a single session of ultrasound-guided percutaneous BRFA (Group A) for benign thyroid nodules were compared with those in 35 untreated patients (Group B) with benign nodules. The benign nature of all the nodules was confirmed by ultrasound-guided fine-needle aspiration biopsy (FNAB), and all the patients had normal thyroid functions. BRFA was performed with a bipolar electrode (CelonProSurge 150–T20) with an output power of 20 W. Nodule volume, thyroid function and clinical symptoms of all the patients were compared before treatment and during follow-up. Results: In Group A, the BRFA procedures were completed with a mean time of 10.02 ± 3.30 min (range, 5.47–16.03 min) and with a mean total energy deposition of 10.747 ± 3704 J (range, 5510–17.770 J). The procedures were tolerated well in all the patients without causing any major complications. At the 6-month follow-up, all of the nodule volume decreased significantly (from 8.81 ± 8.66 to 1.59 ± 1.55 ml, p < 0.001) in Group A, whereas the nodule volume increased from 6.90 ± 3.77 to 7.87 ± 3.95 ml in Group B (p < 0.001). All (100%) the 35 nodules in Group A had volume reduction ratios (VRRs) of >50%, among which 3 (8.57%) had VRRs >90%. In Group A, the clinical symptoms of the patients who had symptoms before BRFA disappeared, whereas in Group B, the patients had no resolution of clinical symptoms at the 6-month follow-up. Conclusion: Ultrasound-guided percutaneous BRFA seems to be an effective and safe method for the treatment of benign thyroid nodules. It may gain a wide use in clinical practice. Advances in knowledge: Based on the comparable efficacy and clinical

  3. Long-term outcomes of percutaneous radiofrequency thermocoagulation for glossopharyngeal neuralgia

    PubMed Central

    Wang, Xiaoping; Tang, Yuanzhang; Zeng, Yuanjie; Ni, Jiaxiang

    2016-01-01

    Abstract The aim of this study was to investigate the long-term results of computed tomography (CT)-guided percutaneous radiofrequency thermocoagulation (PRT) for glossopharyngeal neuralgia (GPN). A retrospective review of medical records for patients with GPN who were treated with CT-guided PRT between 2003 and 2014 was performed to investigate baseline characteristics and immediate outcomes during the hospitalization. Long-term pain relief outcomes and complications were obtained via telephone survey. Duration of pain-free was assessed by Kaplan–Meier analysis. Eighty patients with GPN were treated with CT-guided PRT, and 71 patients could be contacted for the follow-up. The mean length of follow-up after PRT was 56.2 ± 43.3 months. Pain relief occurred in 63 patients (78.8%) immediate after the PRT procedure. The percentage of patients who remained in an “excellent” or “good” pain relief condition was 73.2%, 63.0%, 53.2%, and 43.0% at 1, 3, 5, and 10 years. Postprocedure complication included dysesthesias, dysphagia, and diminished gag reflex. No mortality was observed during or after PRT procedures. This study indicates that CT-guided PRT is a safe and effective method for patients with GPN and should be considered as an alternative treatment for these patients. PMID:27902620

  4. Virtual reality imaging technique in percutaneous radiofrequency rhizotomy for intractable trigeminal neuralgia.

    PubMed

    Meng, Fan-Gang; Wu, Cheng-Yuan; Liu, Yu-Guang; Liu, Lei

    2009-03-01

    Trigeminal neuralgia (TN) is the most common facial neuralgia, and is extremely painful. We evaluate the effectiveness of percutaneous controlled radiofrequency trigeminal rhizotomy (RFTR) assisted by a virtual reality (VR) imaging technique for idiopathic TN. A total of 2769 patients with TN underwent RFTR procedures between June 1986 and March 2007, with VR assisted guiding and electrode positioning in 26 patients from January 2006 to March 2007. A laminal basicranial CT scan (2 mm slice, 16 slices/s) was used during RFTR. The three-dimensional (3D) position of the electrode needle tip and the oval foramen can be seen clearly using this VR technique. The position and depth of the needle was adjusted according to the virtual 3D-CT scan. CT scanning was performed repeatedly until the needle tip was situated in the oval foramen. Usually, the tip of the electrode was adjusted once or twice. Acute pain relief was accomplished in the 26 patients who underwent a single RFTR procedure assisted with VR. No recurrence of pain was noted except in one patient after 16 months. There were no permanent complications or mortality. VR-assisted RFTR represents a minimally invasive, low-risk technique with a higher efficacy compared with traditional RFTR.

  5. Percutaneous radiofrequency ablation of benign thyroid nodules assisted by a virtual needle tracking system.

    PubMed

    Turtulici, Giovanni; Orlandi, Davide; Corazza, Angelo; Sartoris, Riccardo; Derchi, Lorenzo Egildo; Silvestri, Enzo; Baek, Jung Hwan

    2014-07-01

    Our aim was to assess the feasibility and outcome of ultrasound (US)-guided percutaneous radiofrequency (RF) ablation of benign thyroid nodules assisted by a real-time virtual needle tracking (VT) system. Forty-five patients (34 females, mean age ± standard deviation (SD): 44 ± 16 y, range: 29-68 y) with 45 benign non-functioning thyroid nodules (mean volume ± SD: 13.5 ± 6.7 mL, range: 12-22 mL) underwent VT-assisted US-guided RF ablation. Nodule volume was evaluated before treatment and during 6-mo of follow-up. Complication rates and patient satisfaction after treatment were also evaluated. By use of the VT system, the tip of the RF electrode was identified during all ablation procedures. The overall mean volume reduction and complication rate were 72.6 ± 11.3% and 2.5%, respectively. Overall satisfaction at the 6-mo follow-up was rated by patients as positive in 42 cases (93%). The VT system could be useful in thyroid nodule ablation procedures because it is able to track the RF electrode tip even when the tip is obscured by the bubbles produced by the ablative process. VT-assisted RF ablation can be a tolerable, non-surgical treatment for patients with benign non-functioning thyroid nodules.

  6. Process for selected gas oxide removal by radiofrequency catalysts

    DOEpatents

    Cha, C.Y.

    1993-09-21

    This process to remove gas oxides from flue gas utilizes adsorption on a char bed subsequently followed by radiofrequency catalysis enhancing such removal through selected reactions. Common gas oxides include SO[sub 2] and NO[sub x]. 1 figure.

  7. Percutaneous radiofrequency thermocoagulation for trigeminal neuralgia using neuronavigation-guided puncture from a mandibular angle

    PubMed Central

    Ding, Weihua; Chen, Shuping; Wang, Rong; Cai, Jun; Cheng, Yuan; Yu, Liang; Li, Qinghua; Deng, Fang; Zhu, Shengmei; Yu, Wenhua

    2016-01-01

    Abstract Percutaneous radiofrequency thermocoagulation (RFT) of the Gasserian ganglion is an effective treatment for primary trigeminal neuralgia (pTN). Currently Hartel anterior approach is the most commonly used method to access the Gasserian ganglion. However, this approach is associated with high recurrence rate and technical difficulties in certain patients with foramen ovale (FO) anatomical variations. In the present study, we assessed the feasibility of accessing the Gasserian ganglion through the FO from a mandibular angle under computed tomography (CT) and neuronavigation guidance. A total of 108 patients with TN were randomly divided into 2 groups (Group G and Group H) using a random number table. In Group H, Hartel anterior approach was used to puncture the FO; whereas in Group G, a percutaneous puncture through a mandibular angle was used to reach the FO. In both groups, procedures were guided by CT imaging and neuronavigation. The success rates, therapeutic effects, complications, and recurrence rates of the 2 groups were compared. The puncture success rates in Group H and Group G were 52/54 (96.30%) and 49/54 (90.74%), respectively (P = 0.24). The 2 procedural failures in Group H were rescued by using submandibular trajectory, and the 5 failures in Group G were successfully reapproached by Hartel method. Therapeutic effects as measured by Barrow Neurological Institute (BNI) pain scale (P = 0.03) and quality of life (QOL) scores (P = 0.04) were significantly better in Group G than those in Group H at 36 months posttreatment. Hematoma developed in 1/54 (1.85%) cases in Group H, and no cases of hematoma were observed in Group G (P = 0.33). In Group H, RFT resulted in injury to the unintended trigeminal nerve branches and motor fibers in 27/52 (51.92%) cases; in Group G, it resulted in the same type of injury in 7/49 cases (14.29%) (P < 0.01). In Group H, the 24- and 36-month recurrence rates were 12/51 (23.53%) and 20/51 (39

  8. Clinical Assessment of Percutaneous Radiofrequency Ablation for Painful Metastatic Bone Tumors

    SciTech Connect

    Kojima, Hiroyuki Tanigawa, Noboru; Kariya, Shuji; Komemushi, Atsushi; Shomura, Yuzo; Sawada, Satoshi

    2006-12-15

    Purpose. To investigate the pain-alleviating effects of radiofrequency ablation (RFA) on metastatic bone tumors in relation to tumor size, combined therapy, and percent tumor necrosis rate following RFA. Methods. Subjects comprised 24 patients with 28 painful metastatic bone tumors. A 17G internally cooled electrode was inserted into the tumor for CT guidance and ablation was performed. Bone cement was injected following RFA for 4 tumors involving a weight-bearing bone, while 5 tumors were treated using combined RFA and external irradiation. Percent necrosis rate of the tumor was measured using contrast-enhanced computed tomography 1 week after RFA. Results. Improvement in the visual analog scale (VAS) score was 4.6 {+-} 2.2 for large tumors (>5 cm, n = 12), 3.7 {+-} 1.8 for medium-sized tumors (3.1-5.0 cm, n = 11), and 3.5 {+-} 1.7 for small tumors ({<=}3 cm, n = 4), with no significant differences noted among tumor sizes. Improvement in the VAS score was 3.5 {+-} 1.3 for the 4 tumors in the RFA + bone cement group, 3.2 {+-} 1.9 for the 5 tumors in the RFA + radiation therapy group, and 4.8 {+-} 2.2 for the 18 tumors in the RFA group. No significant differences were identified between groups. The improvement in the VAS score was 3.8 {+-} 2.3, 4.0 {+-} 1.9, and 4.7 {+-} 2.6 in patients with tumor necrosis rates of 0-49%, 50-74%, and 75-100%, respectively. No significant association was observed among these three groups. Conclusion. Percutaneous RFA therapy was effective in relieving pain due to metastatic bone tumors. No relationships appear to exist between initial response and tumor size, combined therapy, and percent tumor necrosis.

  9. Osteoid osteoma treated with percutaneous radiofrequency ablation: MR imaging follow-up.

    PubMed

    Lee, Min Hee; Ahn, Joong Mo; Chung, Hye Won; Lim, Hyo K; Suh, Jae Gon; Kwag, Hyon Joo; Hong, Hyun Pyo; Kim, Byung Moon

    2007-11-01

    We evaluated follow-up magnetic resonance (MR) images for osteoid osteoma treated with percutaneous radiofrequency ablation (RFA). Sixteen patients with osteoid osteoma treated with RFA underwent follow-up MR imaging. The protocol included T1, T2 and contrast-enhanced (CE) T1-weighted images with fat saturation at each visit immediately for 17 months after the treatment. MR images were jointly reviewed by two radiologists, regarding the appearance of treated areas, presence of complications, and the best sequence for visualization of signal intensity (SI) changes. The therapeutic response was evaluated to be a clinical success with the relief of pain. The treated areas had a target-like appearance on MR images: a central ablated zone (Z1) surrounded by a band (Z2), and a peripheral area (Z3). Z1 was a non-enhancing, hypointense core on T1, T2WI. Z2 was a well-enhancing, hyperintense rim on T2WI. Z3 was less hyperintense and less enhanced than Z2. All nidi were within Z1. This appearance became evident from 1 week to 1 and 2 months. Following up after 2 months, Z2 showed progressive inward enhancement from the periphery, resulting in almost complete enhancement of Z1 and Z2 with a diminishing size. Z3 gradually showed a decrease in signal change and enhancement. No complications were found. CE-T1WI was the best for visualizing SI changes. The clinical success was achieved in all patients except for one patient with a recurrence at 17 months following treatment that had a second ablation. MR imaging demonstrated a characteristic appearance and subsequent changes of treated areas for osteoid osteoma following RFA.

  10. Percutaneous Vertebroplasty for Pain Management in Patients with Multiple Myeloma: Is Radiofrequency Ablation Necessary?

    SciTech Connect

    Orgera, Gianluigi; Krokidis, Miltiadis; Matteoli, Marco; Varano, Gianluca Maria; La Verde, Giacinto; David, Vincenzo; Rossi, Michele

    2013-05-08

    PurposeThis study was designed to investigate the added role of radiofrequency ablation (RFA) to vertebroplasty on the pain management of patients with multiple myeloma (MM).MethodsThirty-six patients (51–82 years) with vertebral localization of MM were randomly divided into two groups: 18 patients (group A) who underwent RFA and then vertebroplasty, and 18 patients (group B) who underwent only vertebroplasty. Primary endpoints were technical success and pain relief score rate measured by the visual analogue pain scores (VAS) and Roland–Morris Questionnaire (RMQ); secondary endpoint was the amount of administered analgesia. Survival and complications were compared.ResultsTechnical success was 100 % in both groups. The VAS score (at 24 h and 6 weeks postprocedure) decreased in equal manner for both groups from a mean of 9.1–3.4 and 2.0 for group A and from a mean of 9.3–3.0 and 2.3 for group B; RMQ mean score was 19.8 for group A and 19.9 for group B and decreased to a mean of 9.6 and 8.2 for group A and 9.5 and 8.7 for group B. The amount of medication was equally decreased in the two groups. No statistically significant difference was noted. No major complication occurred and two patients died from other causes.ConclusionsThe use of percutaneous vertebroplasty alone appears to be effective for the pain management of the patients with vertebral involvement of multiple myeloma. The use of RFA that includes cost and time does not offer any clear added benefit on the midterm pain management of such patients.

  11. Percutaneous Radiofrequency Ablation with Multiple Electrodes for Medium-Sized Hepatocellular Carcinomas

    PubMed Central

    Lee, Jung; Yoon, Jung-Hwan; Lee, Jae Young; Kim, Se Hyung; Lee, Jeong Eun; Han, Joon Koo; Choi, Byung Ihn

    2012-01-01

    Objective To prospectively evaluate the safety and short-term therapeutic efficacy of switching monopolar radiofrequency ablation (RFA) with multiple electrodes to treat medium-sized (3.1-5.0 cm), hepatocellular carcinomas (HCC). Materials and Methods In this prospective study, 30 patients with single medium-sized HCCs (mean, 3.5 cm; range, 3.1-4.4 cm) were enrolled. The patients were treated under ultrasonographic guidance by percutaneous switching monopolar RFA with a multichannel RF generator and two or three internally cooled electrodes. Contrast-enhanced CT scans were obtained immediately after RFA, and the diameters and volume of the ablation zones were then measured. Follow-up CT scans were performed at the first month after ablation and every three months thereafter. Technical effectiveness, local progression and remote recurrence of HCCs were determined. Results There were no major immediate or periprocedural complications. However, there was one bile duct stricture during the follow-up period. Technical effectiveness was achieved in 29 of 30 patients (97%). The total ablation time of the procedures was 25.4 ± 8.9 minutes. The mean ablation volume was 73.8 ± 56.4 cm3 and the minimum diameter was 4.1 ± 7.3 cm. During the follow-up period (mean, 12.5 months), local tumor progression occurred in three of 29 patients (10%) with technical effectiveness, while new HCCs were detected in six of 29 patients (21%). Conclusion Switching monopolar RFA with multiple electrodes in order to achieve a sufficient ablation volume is safe and efficient. This method also showed relatively successful therapeutic effectiveness on short-term follow up for the treatment of medium-sized HCCs. PMID:22247634

  12. Percutaneous Radiofrequency Ablation of Lung Cancer Presenting as Ground-Glass Opacity

    SciTech Connect

    Iguchi, Toshihiro Hiraki, Takao Gobara, Hideo Fujiwara, Hiroyasu Matsui, Yusuke; Soh, Junichi Toyooka, Shinichi; Kiura, Katsuyuki; Kanazawa, Susumu

    2015-04-15

    PurposeWe retrospectively evaluated the outcomes of lung cancer patients presenting with ground-glass opacity (GGO) who received radiofrequency ablation (RFA).MethodsSixteen patients (5 men and 11 women; mean age, 72.6 years) with 17 lung cancer lesions showing GGO (mean long axis diameter, 1.6 cm) underwent a total of 20 percutaneous computed tomography (CT) fluoroscopy-guided RFA sessions, including three repeated sessions for local progression. Lung cancer with GGO was defined as a histologically confirmed malignant pulmonary lesion with a GGO component accounting for >50 % of the lesion on high-resolution CT. Procedure outcomes were evaluated.ResultsThere were no major complications. Pneumothorax occurred in 15 of 20 treatment sessions: 14 were asymptomatic, and 1 required chest tube placement but resolved satisfactorily within 48 h. Minor pulmonary hemorrhage occurred in two and mild pneumonitis in one. The median tumor follow-up period was 61.5 (range 6.1–96.6) months. The effectiveness rates of the primary and secondary techniques were 100 and 100 % at 1 year, 93.3 and 100 % at 2 years, and 78.3 and 92.3 % at 3 years, respectively. The median patient follow-up period was 65.6 (range 6.1–96.6) months. One patient died owing to recurrent other cancer 11.7 months after RFA, whereas the other 15 remained alive. Overall survival and disease-specific survival rates were 93.3 and 100 % at 1 year and 93.3 and 100 % at 5 years, respectively.ConclusionsRFA for lung cancer with GGO was safe and effective, and resulted in promising survival rates.

  13. Percutaneous Radiofrequency Thermocoagulation Under Fluoroscopic Image-Guidance for Idiopathic Trigeminal Neuralgia

    PubMed Central

    Kim, Hyung-Suk; Kim, Il-Sup; Yang, Seung-Ho; Lee, Sang-Won

    2011-01-01

    Objective We retrospectively investigated the long-term results of percutaneous radiofrequency thermocoagulation (RFT) using fluoroscopic image-guidance for treatment of trigeminal neuralgia. Methods A total of 38 patients diagnosed and treated with RFT as an idiopathic trigeminal neuralgia were investigated. To minimize the risks related to conventional technique based on cutaneous landmarks, and to eliminate the need to frequent reposition of cannula, we adopted a technique of image-guided fluoroscopic cannulation of the foramen ovale. To minimize sensory complication following thermal lesion, our target response was a generation of a lesion with mild to moderate hypalgesia rather than dense hypalgesia. Results The immediate pain-relief was achieved in all patients underwent RFT. With mean duration of follow-up of 38.2 months (range,12-72), 11 (28.9%) experienced recurrence of pain. The mean timing of recurrence was 26.1 months (range,12-46). A 42.7% recurrence rate was estimated by Kaplan-Meier analysis for the 38 patients at 46 months; 20.2% within 2 years, 29.1% within 3 years. In the long-term, 27 patients (71%) and 6 patients (15.8%) showed Barrow Neurological Institute (BNI) score I and BNI score II responses. 3 (7.9%) patients was assessed as BNI score III, 2 patients (5.3%) showed BNI score IV response. As a complication, troublesome dysesthesia occurred in 3 of 38 patients (7.9%), however, there was no permanent cranial nerve palsy or morbidity. Conclusion These results indicates that RFT under fluoroscopic image-guided cannulation of foramen ovale is a safe, effective, and reliable means of treating trigeminal neuralgia. PMID:22259692

  14. Percutaneous trigeminal ganglion radiofrequency thermocoagulation alleviates anxiety and depression disorders in patients with classic trigeminal neuralgia

    PubMed Central

    Tang, YuanZhang; Ma, Ling; Li, Na; Guo, Yuna; Yang, Liqiang; Wu, Baishan; Yue, Jianning; Wang, Qi; Liu, Jingjie; Ni, Jia-xiang

    2016-01-01

    Abstract Trigeminal neuralgia (TN) is a neurological condition that presents as excruciating facial pain. Depression and anxiety are commonly associated with TN; however, anxiety and depression disorders in patients with TN and the effects of the various therapeutic strategies for TN on these disorders are not well studied. To evaluate depression and anxiety in patients with trigeminal neuralgia (TN), identify factors that predict their occurrence and study the effect of the percutaneous trigeminal ganglion radiofrequency thermocoagulation (PRT) procedure for alleviating pain on depression and anxiety. Patients with classic TN, who received PRT treatment, were consecutively recruited between October 2014 and October 2015. Severity of pain was determined using the visual analogue scale (VAS) score. Beck Depression Inventory-II (BDI) and Beck anxiety Inventory (BAI) were used to evaluate depression and anxiety disorders pre- and post-PRT. Medical, demographic, and psychosocial backgrounds were also assessed as predictive factors. A BDI score of ≥14 represented depression and BAI score of ≥45 represented anxiety. VAS, BDI, and BAI scores were collected at the time of admission and on the day of discharge. Of the 167 patients who participated in the study, 121 (72.5%) had depression and 34 (20.4%) suffered anxiety. Pre-PRT procedure, female sex, age >50 years, ineffective treatment, and high pain intensity (VAS ≥7) predicted the development of depression and anxiety. Post-PRT procedure, all patients who experienced pain relief also reported amelioration of depression and anxiety. A considerable percentage of patients with TN developed depression and anxiety. Patients who were female, older than 50 years, or suffered from failure treatment and severe pain (VAS>7), were at higher risk of depression and anxiety development. Complete alleviation of pain by using surgical PRT could immediately attenuate depressive and anxiety disorders associated with TN. PMID

  15. Use of ultrasound and fluoroscopy guidance in percutaneous radiofrequency lesioning of the sensory branches of the femoral and obturator nerves.

    PubMed

    Chaiban, Gassan; Paradis, Tyler; Atallah, Joseph

    2014-04-01

    Hip pain is a common condition that is often seen in patients with multiple comorbidities. Often surgery is not an option due to these comorbidities. Percutaneous radiofrequency lesioning of the articular branches of the obturator and femoral nerves is an alternative treatment for hip pain. Traditionally, fluoroscopy is used to guide needle placement. We report a case where a novel approach was used with ultrasound guidance to visualize vascular and soft tissue structures in real time. The use of ultrasound might help to guide the needle to avoid vascular complications due to anatomical variation between patients. © 2013 World Institute of Pain.

  16. Percutaneous thrombin injection treatment of a gluteal pseudoaneurysm following radiofrequency ablation of a hip osteoid osteoma in a 6-year-old boy.

    PubMed

    Kumar, Abhishek; Ramchand, Tekchand; Contractor, Sohail

    2014-12-01

    Osteoid osteomas are benign bone lesions that present with bone pain in children and young adults. Over the last 2 decades, radiofrequency ablation has become the mainstay of treatment and is now preferred over surgical resection. Major complications of the procedure are very rare, consisting mostly of local skin burns. We present a case of a child presenting with a gluteal pseudoaneursym following CT-guided radiofrequency ablation of an acetabular osteoid osteoma, which was then treated successfully with percutaneous thrombin injection.

  17. Thermo-sensitive hydrogel for preventing bowel injury in percutaneous renal radiofrequency ablation.

    PubMed

    Wang, Xin; Zhao, Xiaozhi; Lin, Tingsheng; Guo, Hongqian

    2016-10-01

    Percutaneous radiofrequency ablation (PRFA) has been used to ablate renal neoplasms with good outcome. However, if bowel lies adjacent to a tumor, ablation increases the risk of thermal bowel injury, and the consequences could be fatal. We describe the technique, effectiveness and safety of using thermo-sensitive hydrogel as insulation to displace the bowel away during PRFA. The study was divided into two main parts: the in vitro and in vivo studies. In in vitro study, to explore the heat insulation of hydrogel, the rabbit kidney was entirely embedded in hydrogel, and then radiofrequency ablation was performed; the temperature on the gel-air and gel-kidney interfaces was measured. In in vivo study, hydrogel of poloxamer 407, 25 % concentration (w/v), was instilled into the perinephric space of 10 rabbits under CT guidance to separate the kidney from adjacent bowel before PRFA performed in the targeted parenchyma in the gel group. For the control group, PRFA was performed in similar portions of 10 rabbits without instillation of hydrogel. Some parameters were recorded such as kidney-to-bowel and electrode-to-bowel distance. Immediately after PRFA, distribution of hydrogel was evaluated and the dimension of radiofrequency ablation zone was measured; bowel thermal injury was compared between the gel and control groups by gross anatomy and histopathological examination. To assess safety, two additional follow-up groups with 10 rabbits in each were set; after PRFA, CT scan was performed every 2 days; gel absorption, thermal damage and some other complications were evaluated during the period. In in vitro study, temperature was significantly lower at the gel-air than gel-kidney interface (P < .05), and the temperature gradient was positively associated with gel thickness. In in vivo study, hydrogel was instilled successfully in all rabbits in the gel group. The kidney-to-bowel and electrode-to-bowel distances were larger in the gel than control group [(1.1 ± 0.6

  18. [Percutaneous ablation of atrioventricular junction by radiofrequency current in resistant atrial arrhythmia. Results of a series of 24 patients].

    PubMed

    Sebag, C; Lavergne, T; Ollitrault, J; Cabanis, C; Le Heuzey, J Y; Slama, M; Motté, G; Guize, L

    1992-06-01

    Catheter ablation of the atrioventricular junction may be proposed for the treatment of certain atrial arrhythmias resistant to antiarrhythmic therapy. One of the methods currently being evaluated uses radio-frequency energy which has certain advantages compared with direct current ablation because of the progressive and limited lesions it produces. This technique was used in 24 patients with atrial arrhythmias resistant to antiarrhythmic therapy. The radio-frequency energy was delivered without general anaesthesia with HAT 100 and 200 (OSYPKA) generators in the unipolar mode (average 17.4 watts) for an average period of 22.3 +/- 8 seconds. The catheter (8F USCI suction catheter in the first 18 patients and a 7F Polaris Mansfield, deflectable catheter with a large distal electrode in the remainder) was positioned at the nodo-hisian junction at a point where the two distal electrodes recorded a large atrial deflection and the smallest possible hisian potential. The conduction defects induced during the acute phase generally remain stable in cases of complete atrioventricular block and tend to regress in cases of incomplete atrioventricular block despite initial control of atrioventricular conduction. During follow-up (21 +/- 16 months), 14 patients (58%) remained in complete atrioventricular block, 4 patients (17%) had controlled atrioventricular conduction with an acceptable ventricular rate with associated previously ineffective antiarrhythmic therapy. Radio-frequency ablation was a failure in 6 patients (25%). There were no haemodynamic, rhythmic or ischaemic complications during the acute phase or during follow-up. These results suggest radio-frequency energy is a seductive alternative to direct current ablation for percutaneous modification of atrioventricular conduction in patients with refractory atrial arrhythmias. However, simple modulation of atrioventricular conduction gives aleatory results due to the tendency to regression during follow-up. On the other

  19. Various complications of percutaneous radiofrequency ablation for hepatic tumors: radiologic findings and technical tips.

    PubMed

    Kwon, Heon-Ju; Kim, Pyo Nyun; Byun, Jae Ho; Kim, Kyoung Won; Won, Hyung Jin; Shin, Yong Moon; Lee, Moon-Gyu

    2014-11-01

    Radiofrequency ablation is a safe and effective treatment for primary and secondary liver malignancies and has a low complication rate; however, there are various radiofrequency ablation-related complications which can occur from the thorax to the pelvis. Although most of these complications are usually minor and self-limited, they may become fatal if diagnosis and treatment are delayed. It is important for radiologists performing radiofrequency ablation to have a perspective regarding the possible radiofrequency ablation-related complications and their risk factors as well as the radiologic findings for their timely detection and increase of the treatment efficacy, and thereby encouraging the use of the radiofrequency ablation technique. This article illustrates the various imaging features of common and rare radiofrequency ablation-related complications as well as offers technical tips in order to avoid these complications. © The Foundation Acta Radiologica 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  20. Species-selective confinement of atoms dressed with multiple radiofrequencies

    NASA Astrophysics Data System (ADS)

    Bentine, E.; Harte, T. L.; Luksch, K.; Barker, A. J.; Mur-Petit, J.; Yuen, B.; Foot, C. J.

    2017-05-01

    Methods to manipulate the individual constituents of an ultracold quantum gas mixture are essential tools for a number of applications, such as the direct quantum simulation of impurity physics. We investigate a scheme in which species-selective control is achieved using magnetic potentials dressed with multiple radiofrequencies, exploiting the different Landé {g}F-factors of the constituent atomic species. We describe a mixture dressed with two frequencies, where atoms are confined in harmonic potentials with a controllable degree of overlap between the two atomic species. This is then extended to a four radiofrequency scheme in which a double well potential for one species is overlaid with a single well for the other. The discussion is framed with parameters that are suitable for a {}85{Rb} and {}87{Rb} mixture, but is readily generalised to other combinations.

  1. Percutaneous radiofrequency ablation of lung metastases from colorectal carcinoma under C-arm cone beam CT guidance.

    PubMed

    Amouyal, G; Pernot, S; Déan, C; Cholley, B; Scotté, F; Sapoval, M; Pellerin, O

    2017-05-29

    The aim of this study was to assess the feasibility, safety and efficacy of percutaneous radiofrequency ablation of lung metastases from colorectal carcinoma using C-arm cone beam computed tomography (CBCT) guidance. This single-center prospective observational study was performed from August 2013 to August 2016, and included consecutive patients referred for radiofrequency ablation of lung metastases from colorectal cancer. Radiofrequency ablation procedures were performed under C-arm CBCT guidance. Feasibility was assessed by probe accuracy placement, time to accurate placement and number of C-arm CBCT acquisitions to reach the target lesion. Safety was assessed by the report of adverse event graded using the common terminology criteria for adverse events (CTCAE-V4.0). Efficacy was assessed by metastases response rate using RECIST 1.1 and (18)FDG-PET-CT tumor uptake at 6months. Fifty-four consecutive patients (32 men, 22 women) with a mean age of 63±8 (SD) years (range: 51-81years) with a total of 56 lung metastasis from colorectal metastases were treated in a single session. The mean tumor diameter was 25.6±4.5 (SD)mm (range: 17-31mm). Median time to insert the needle into the target lesion was 10min (range: 5-25min). Median number of needles repositioning and C-arm CBCT acquisition per patient was 1 (range: 0-3) and 4 (range: 3-6) respectively. The accuracy for radiofrequency ablation probe placement was 2±0.2 (SD)mm (range: 0-9mm). Pneumothorax requiring chest tube placement occurred in one patient (CTCAE-V4.0 grade 3). At 6months, all patients were alive with tumor response rate of -27% and had no significant activity on the (18)FDG-PET CT follow-up. Percutaneous radiofrequency ablation of lung metastases from colorectal cancer under C-arm CBCT guidance is feasible and safe, with immediate and short-term results similar to those obtained using conventional CT guidance. Copyright © 2017 Editions françaises de radiologie. Published by Elsevier Masson SAS

  2. Benign thyroid nodules treatment using percutaneous laser ablation (PLA) and radiofrequency ablation (RFA).

    PubMed

    Mauri, Giovanni; Cova, Luca; Monaco, Cristian Giuseppe; Sconfienza, Luca Maria; Corbetta, Sabrina; Benedini, Stefano; Ambrogi, Federico; Milani, Valentina; Baroli, Alberto; Ierace, Tiziana; Solbiati, Luigi

    2016-11-15

    To evaluate the reduction over time of benign thyroid nodules treated using percutaneous laser ablation (PLA) and radiofrequency ablation (RFA) by the same equipe. Ninety patients (age 55.6 ± 14.1 years) underwent ablation for benign thyroid nodule causing compression/aesthetic dissatisfaction from 2011. Fifty-nine (age 55.8 ± 14.1 years) underwent RFA and 31 (age 55.2 ± 14.2 years) PLA, ultrasound guided. Technical success, complications, duration of ablation and treatment, energy deployed, volumetric percentage reduction at 1, 6 and 12 months were derived. A regression model for longitudinal measurements was used with random intercept and random slope. Values are expressed as mean ± standard deviation or N (%). Technical success was always obtained. No major complications occurred. Mean ablation time was 30.1 ± 13.8 vs. 13.9 ± 5.9 min (p < .0001) and mean energy deployment was 5422.3 ± 2484.5 J vs. 34 662.7 ± 15 812.3 J in PLA vs. RFA group. Mean volume reduced from 20.3 ± 16.4 ml to 13.17 ± 10.74 ml (42% ± 17% reduction) at 1st month, 8.7 ± 7.4 ml (60% ± 15% reduction) at 6th month and 7.1 ± 7.7 ml (70%% ± 16% reduction) at 12th month, in PLA group, and from 32.7 ± 19.5 ml to 17.2 ± 12.9 ml (51%±15% reduction) at 1st month, 12.8 ± 9.6 ml (64 ± 14% reduction) at 6th month and 9.9 ± 9.2 ml (74% ± 14% reduction) at 12th month in RFA group. No difference in time course of the relative volume reduction between the two techniques was found. RFA and PLA are similarly feasible, safe and effective in treating benign thyroid nodules when performed by the same equipe. RFA is faster than PLA but require significantly higher energy.

  3. Kidney neoplasms: renal halo sign after percutaneous radiofrequency ablation--incidence and clinical importance in 101 consecutive patients.

    PubMed

    Schirmang, Todd C; Mayo-Smith, William W; Dupuy, Damian E; Beland, Michael D; Grand, David J

    2009-10-01

    To describe the incidence and clinical importance of the renal halo sign after percutaneous radiofrequency ablation (RFA) of renal neoplasms. Institutional review board approval was obtained for this HIPAA-compliant retrospective study. The study population consisted of 101 consecutive patients with 106 solid renal neoplasms that were treated with percutaneous RFA. Postablation computed tomographic (CT) and magnetic resonance (MR) images were retrospectively reviewed by three board-certified radiologists to determine the presence of the renal halo sign. Statistical analyses were performed to determine reader agreement and assess the effect that tumor size and location, radiofrequency (RF) applicator type, RFA treatment time and success, maximum RFA treatment temperature, and number of RF applications performed had on development of the renal halo sign. The renal halo sign developed in 79 (75%) of the 106 ablated tumors. Average imaging follow-up lasted 25 months (range, 1-98 months). The renal halo sign appeared, on average, 6 months (range, 1 month to 3 years) after RFA. The renal halo sign resolved in five (6%) of 79 tumors treated. Interobserver agreement for the presence of the renal halo sign was high. Tumor size and location, RF applicator type, RFA treatment time and success, maximum RFA treatment temperature, and number of RF applications performed were not independent predictors of renal halo sign development. The renal halo sign is seen in 75% of patients after percutaneous RFA of renal neoplasms. It may decrease in size over time; however, it rarely disappears. It is important to recognize this sign, as it can be mistaken for recurrent tumor or angiomyolipoma by radiologists who are not familiar with RFA.

  4. In vivo intracardiac optical coherence tomography imaging through percutaneous access: toward image-guided radio-frequency ablation

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Kang, Wei; Carrigan, Thomas; Bishop, Austin; Rosenthal, Noah; Arruda, Mauricio; Rollins, Andrew M.

    2011-11-01

    Complete catheter-tissue contact and permanent tissue destruction are essential for efficient radio-frequency ablation (RFA) during cardiac arrhythmia treatment. Current methods of monitoring lesion formation are indirect and unreliable. The purpose of this study is to evaluate the feasibility of using optical coherence tomography (OCT) catheter to image endocardial wall in actively beating hearts through percutaneous access. We reported the first in vivo intracardiac OCT imaging through percutaneous access with a thin and flexible OCT catheter. This is a critical step toward image-guided RFA in a clinical setting. A cone-scanning forward-viewing OCT catheter was advanced into beating hearts through percutaneous access in four swine. The OCT catheter was steered by an introducer to touch the endocardial wall. We are able to acquire high quality OCT images in beating hearts, observe the polarization-related artifacts induced by the birefringence of myocardium, and readily evaluate catheter-tissue contact. The observations indicate that OCT could be a promising technique for in vivo guidance of RFA.

  5. Percutaneous T2 and T3 Radiofrequency Sympathectomy for Complex Regional Pain Syndrome Secondary to Brachial Plexus Injury: A Case Series

    PubMed Central

    Phui, Vui Eng; Nizar, Abd Jalil; Yeo, Sow Nam

    2013-01-01

    Complex regional pain syndrome secondary to brachial plexus injury is often severe, debilitating and difficult to manage. Percuteneous radiofrequency sympathectomy is a relatively new technique, which has shown promising results in various chronic pain disorders. We present four consecutive patients with complex regional pain syndrome secondary to brachial plexus injury for more than 6 months duration, who had undergone percutaneous T2 and T3 radiofrequency sympathectomy after a diagnostic block. All four patients experienced minimal pain relief with conservative treatment and stellate ganglion blockade. An acceptable 6 month pain relief was achieved in all 4 patients where pain score remained less than 50% than that of initial score and all oral analgesics were able to be tapered down. There were no complications attributed to this procedure were reported. From this case series, percutaneous T2 and T3 radiofrequency sympathectomy might play a significant role in multi-modal approach of CRPS management. PMID:24156009

  6. Experiences in US-Guided Percutaneous Radiofrequency Ablation of 44 Renal Tumors in 31 Patients: Analysis of Predictors for Complications and Technical Success

    SciTech Connect

    Veltri, Andrea Calvo, Amedeo; Tosetti, Irene; Pagano, Eva; Genovesio, Andrea; Virzi, Valentina; Ferrando, Ugo; Fontana, Dario; Gandini, Giovanni

    2006-10-15

    Purpose. Preliminary clinical studies have shown the feasibility, safety, and efficacy of radiofrequency thermal ablation (RFA) of renal tumors, but only a few have analyzed the prognostic factors for technical success and there are no long-term results. Our objective was to statistically evaluate our mid-term results of percutaneous US-guided RFA in order to define predictors for complications and technical success. Methods. We selected for treatment 44 tumors in 31 patients (24 with renal cell carcinoma, 7 with hereditary tumors, 15 with a solitary kidney), up to 5 cm in diameter. Results. Eight adverse events occurred; 3 (6.8%) were major complications, successfully treated with interventional radiology procedures in 2 cases. Exophytic extension of the tumor was protective against complications (p 0.040). Technical success was obtained in 38 lesions after one RFA session and in 39 (89%) after one more session, when possible. At the end of treatment, central extension was the only negative predictor for technical success (p = 0.007), while neither size >3 cm (p = 0.091) nor other prognostic factors were statistically significant. Conclusion. US-guided percutaneous RFA can be proposed for non-central renal tumors up to 5 cm, also in patients without surgical contraindications, thanks to a low incidence of complications and a high success rate. Randomized controlled trials versus surgery are now needed to investigate long-term comparative results.

  7. Development of a simultaneous cryo-anchoring and radiofrequency ablation catheter for percutaneous treatment of mitral valve prolapse.

    PubMed

    Boronyak, Steven M; Merryman, W David

    2012-09-01

    Mitral valve prolapse (MVP) is one subtype of mitral valve (MV) disease and is often characterized by enlarged leaflets that are thickened and have disrupted collagen architecture. The increased surface area of myxomatous leaflets with MVP leads to mitral regurgitation, and there is need for percutaneous treatment options that avoid open-chest surgery. Radiofrequency (RF) ablation is one potential therapy in which resistive heating can be used to reduce leaflet size via collagen contracture. One challenge of using RF ablation to percutaneously treat MVP is maintaining contact between the RF ablation catheter tip and a functioning MV leaflet. To meet this challenge, we have developed a RF ablation catheter with a cryogenic anchor for attachment to leaflets in order to apply RF ablation. We demonstrate the effectiveness of the dual-energy catheter in vitro by examining changes in leaflet biaxial compliance, thermal distribution with infrared (IR) imaging, and cryogenic anchor strength. We report that 1250 J of RF energy with cryo-anchoring reduced the determinant of the deformation gradient tensor at systolic loading by 23%. IR imaging revealed distinct regions of cryo-anchoring and tissue ablation, demonstrating that the two modalities do not counteract one another. Finally, cryogenic anchor strength to the leaflet was reduced but still robust during the application of RF energy. These results indicate that a catheter having combined RF ablation and cryo-anchoring provides a novel percutaneous treatment strategy for MVP and may also be useful for other percutaneous procedures where anchored ablation would provide more precise spatial control.

  8. Percutaneous bipolar radiofrequency thermocoagulation for the treatment of lumbar disc herniation.

    PubMed

    Zeng, Zhenhua; Yan, Min; Dai, Yi; Qiu, Weidong; Deng, Shuo; Gu, Xinzhu

    2016-08-01

    Lumbar disc herniation is usually managed with conservative treatment or surgery. However, conservative therapy seldom yields good results, and surgery is associated with multiple complications. This study aimed to assess bipolar radiofrequency thermocoagulation for the treatment of lumbar disc herniation. A total of 168 patients with lumbar disc herniation suitable for radiofrequency thermocoagulation were enrolled and randomized to monopolar radiofrequency thermocoagulation (control group, n=84) or bipolar radiofrequency thermocoagulation (experimental group, n=84) treatment groups. Ablation sites were targeted under CT scan guidance, and consecutive radiofrequency therapy was used. One and two probes were used for monopolar and bipolar thermocoagulation, respectively. Thermocoagulation was achieved at 50°C, 60°C, and 70°C for 60s each, 80°C for 90s, and 92°C for 100s. Symptoms and complications were evaluated using the modified Macnab criteria and Visual Analog Scale at 7, 30, and 180days postoperatively. At 180days, a significantly higher efficacy rate was obtained in the experimental group compared with control patients (91.6% versus 79.7%, P<0.05). No severe complications were occurred in either group. Targeted ablation via bipolar radiofrequency thermocoagulation is efficient for lumbar disc herniation treatment, and should be further explored for broad clinical application. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Renal cell carcinoma metastasis involving vertebral hemangioma: dual percutaneous treatment by navigational bipolar radiofrequency ablation and high viscosity cement vertebroplasty.

    PubMed

    Zerlauth, Jean-Baptiste; Meuli, Reto; Dunet, Vincent

    2017-09-01

    The case of a 70-year-old woman with progressive renal cell carcinoma (RCC) metastatic invasion of a L3 vertebral hemangioma treated by dual percutaneous radiofrequency ablation (RFA) and vertebroplasty is reported. The patient was surgically treated for RCC in 2001. Chemotherapy and immunotherapy were introduced in 2013 for ovarian, bladder and cerebral metastatic disease. An asymptomatic L3 benign hemangioma was noticed at this time. One-year CT and MRI follow-up studies demonstrated a nodular isolated soft tissue lesion involving the anterior edge of the hemangioma. Percutaneous treatment consisted of a L3 vertebral body unipedicular approach to perform a biopsy, RFA with a navigational bipolar RFA device and vertebroplasty using high viscosity cement. Histopathological examination confirmed metastasis of RCC. The 5-month spinal MRI and CT examinations demonstrated complete disappearance of the tumor. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  10. Radiographic Local Control of Spinal Metastases with Percutaneous Radiofrequency Ablation and Vertebral Augmentation.

    PubMed

    Wallace, A N; Tomasian, A; Vaswani, D; Vyhmeister, R; Chang, R O; Jennings, J W

    2016-04-01

    Combination radiofrequency ablation and vertebral augmentation is an emerging minimally invasive therapy for patients with metastatic spine disease who have not responded to or have contraindications to radiation therapy. The purpose of this study was to evaluate the rate of radiographic local control of spinal metastases treated with combination radiofrequency ablation and vertebral augmentation. We retrospectively reviewed our tumor ablation database for all patients who underwent radiofrequency ablation and vertebral augmentation of spinal metastases between April 2012 and July 2014. Tumors treated in conjunction with radiation therapy were excluded. Tumor characteristics, procedural details, and complications were recorded. Posttreatment imaging was reviewed for radiographic evidence of tumor progression. Fifty-five tumors met study inclusion criteria. Radiographic local tumor control rates were 89% (41/46) at 3 months, 74% (26/35) at 6 months, and 70% (21/30) at 1 year after treatment. Clinical follow-up was available in 93% (51/55) of cases. The median duration of clinical follow-up was 34 weeks (interquartile range, 15-89 weeks), during which no complications were reported and no patients had clinical evidence of metastatic spinal cord compression at the treated levels. Combination radiofrequency ablation and vertebral augmentation appears to be an effective treatment for achieving local control of spinal metastases. A prospective clinical trial is now needed to replicate these results. © 2016 by American Journal of Neuroradiology.

  11. First experience of percutaneous radio-frequency ablation for atrial flutter and atrial fibrillation in a patient with HeartMate II left ventricular assist device.

    PubMed

    Maury, Philippe; Delmas, Clement; Trouillet, Charlotte; Slaughter, Mark S; Lairez, Olivier; Galinier, Michel; Roncalli, Jerome; Bertrand, David; Mathevet, Lydie; Duparc, Alexandre; Salvador, Michelle; Delay, Marc; Dambrin, Camille

    2010-10-01

    We report the first case of percutaneous radio-frequency (RF) ablation procedure in a patient implanted with a HeartMate II left ventricular assist device for refractory heart failure. This procedure was performed for poorly tolerated recurrent atrial arrhythmias. No harmful consequence happened during or after the procedure despite the potential electromagnetic interferences existing between the RF delivery and the functioning of the device.

  12. Considering Angle Selection When Using Ultrasound Electrode Displacement Elastography to Evaluate Radiofrequency Ablation of Tissues

    PubMed Central

    Li, Qiang; Chen, Pin-Yu; Wang, Chiao-Yin; Liu, Hao-Li; Teng, Jianfu

    2014-01-01

    Percutaneous radiofrequency ablation (RFA) is a minimally invasive treatment to thermally destroy tumors. Ultrasound-based electrode-displacement elastography is an emerging technique for evaluating the region of RFA-induced lesions. The angle between the imaging probe and the RFA electrode can influence electrode-displacement elastography when visualizing the ablation zone. We explored the angle effect on electrode-displacement elastography to measure the ablation zone. Phantoms embedded with meatballs were fabricated and then ablated using an RFA system to simulate RFA-induced lesions. For each phantom, a commercial ultrasound scanner with a 7.5 MHz linear probe was used to acquire raw image data at different angles, ranging from 30° to 90° at increments of 10°, to construct electrode-displacement images and facilitate comparisons with tissue section images. The results revealed that the ablation regions detected using electrode-displacement elastography were highly correlated with those from tissue section images when the angle was between 30° and 60°. However, the boundaries of lesions were difficult to distinguish, when the angle was larger than 60°. The experimental findings suggest that angle selection should be considered to achieve reliable electrode-displacement elastography to describe ablation zones. PMID:24971347

  13. Percutaneous radiofrequency lesions adjacent to the dorsal root ganglion alleviate spasticity and pain in children with cerebral palsy: pilot study in 17 patients

    PubMed Central

    2010-01-01

    Background Cerebral palsy (CP) may cause severe spasticity, requiring neurosurgical procedures. The most common neurosurgical procedures are continuous infusion of intrathecal baclofen and selective dorsal rhizotomy. Both are invasive and complex procedures. We hypothesized that a percutaneous radiofrequency lesion of the dorsal root ganglion (RF-DRG) could be a simple and safe alternative treatment. We undertook a pilot study to test this hypothesis. Methods We performed an RF-DRG procedure in 17 consecutive CP patients with severe hip flexor/adductor spasms accompanied by pain or care-giving difficulties. Six children were systematically evaluated at baseline, and 1 month and 6 months after treatment by means of the Modified Ashworth Scale (MAS), Gross Motor Function Measure (GMFM) and a self-made caregiver's questionnaire. Eleven subsequent children were evaluated using a Visual Analogue Scale (VAS) for spasticity, pain and ease of care. Results A total of 19 RF-DRG treatments were performed in 17 patients. We found a small improvement in muscle tone measured by MAS, but no effect on the GMFM scale. Despite this, the caregivers of these six treated children unanimously stated that the quality of life of their children had indeed improved after the RF-DRG. In the subsequent 11 children we found improvements in all VAS scores, in a range comparable to the conventional treatment options. Conclusion RF-DRG is a promising new treatment option for severe spasticity in CP patients, and its definitive effectiveness remains to be defined in a randomised controlled trial. PMID:20569438

  14. Is Antibiotic Prophylaxis for Percutaneous Radiofrequency Ablation (RFA) of Primary Liver Tumors Necessary? Results From a Single-Center Experience

    SciTech Connect

    Bhatia, Shivank S.; Echenique, Ana Froud, Tatiana Suthar, Rekha Lawson, Ivy Dalal, Ravi; Yrizarry, Jose Narayanan, Govindarajan

    2015-08-15

    PurposeThe purpose of this study was to evaluate need for antibiotic prophylaxis for radiofrequency ablation (RFA) of liver tumors in patients with no significant co-existing risk factors for infection.Materials and MethodsFrom January 2004 to September 2013, 83 patients underwent 123 percutaneous RFA procedures for total of 152 hepatocellular carcinoma (HCC) lesions. None of the patients had pre-existing biliary enteric anastomosis (BEA) or any biliary tract abnormality predisposing to ascending biliary infection or uncontrolled diabetes mellitus. No pre- or post-procedure antibiotic prophylaxis was provided for 121 procedures. Data for potential risk factors were reviewed retrospectively and analyzed for the frequency of infectious complications, including abscess formation.ResultsOne patient (1/121 (0.8 %) RFA sessions) developed a large segment 5 liver abscess/infected biloma communicating with the gallbladder 7 weeks after the procedure, successfully treated over 10 weeks with IV and PO antibiotic therapy and percutaneous catheter drainage. This patient did not receive any antibiotics prior to RFA. During the procedure, there was inadvertent placement of RFA probe tines into the gallbladder. No other infectious complications were documented.ConclusionThese data suggest that the routine use of prophylactic antibiotics for liver RFA is not necessary in majority of the patients undergoing liver ablation for HCC and could be limited to patients with high-risk factors such as the presence of BEA or other biliary abnormalities, uncontrolled diabetes mellitus, and large centrally located tumors in close proximity to central bile ducts. Larger randomized studies are needed to confirm this hypothesis.

  15. Percutaneous radiofrequency ablation of hepatic tumours: factors affecting technical failure of artificial ascites formation using an angiosheath.

    PubMed

    Kang, T W; Lee, M W; Hye, M J; Song, K D; Lim, S; Rhim, H; Lim, H K; Cha, D I

    2014-12-01

    To evaluate the technical feasibility of artificial ascites formation using an angiosheath before percutaneous radiofrequency ablation (RFA) for hepatic tumours and to determine predictive factors affecting the technical failure of artificial ascites formation. This retrospective study was approved by the institutional review board. One hundred and thirteen patients underwent percutaneous RFA of hepatic tumours after trying to make artificial ascites using an angiosheath to avoid collateral thermal damage. The technical success rate of making artificial ascites using an angiosheath and conversion rate to other techniques after initial failure of making artificial ascites were evaluated. The technical success rate for RFA was assessed. In addition, potential factors associated with technical failure including previous history of transcatheter arterial chemoembolization (TACE) or RFA, type of abdominal surgery, and adjacent perihepatic structures were reviewed. Predictive factors for the technical failure of artificial ascites formation were analysed using multivariate analysis. The technical success rates of artificial ascites formation by angiosheath and that of RFA were 84.1% (95/113) and 97.3% (110/113), respectively. The conversion rate to other techniques after the failure of artificial ascites formation using an angiosheath was 15.9% (18/113). Previous hepatic resection was the sole independent predictive factor affecting the technical failure of artificial ascites formation (p<0.001, odds ratio = 29.03, 95% confidence interval: 4.56-184.69). Making artificial ascites for RFA of hepatic tumours using an angiosheath was technically feasible in most cases. However, history of hepatic resection was a significant predictive factor affecting the technical failure of artificial ascites formation. Copyright © 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  16. Percutaneous radiofrequency ablation for hepatic tumors abutting the diaphragm: clinical assessment of the heat-sink effect of artificial ascites.

    PubMed

    Nam, Sang Yu; Rhim, Hyunchul; Kang, Tae Wook; Lee, Min Woo; Kim, Young-Sun; Choi, Dongil; Lee, Won Jae; Park, Yulri; Chang, Ilsoo; Lim, Hyo K

    2010-02-01

    This study was designed to assess whether artificial ascites has a heat-sink effect on the ablation zone for percutaneous radiofrequency ablation (RFA) of hepatic tumors abutting the diaphragm. We retrospectively assessed 28 patients who underwent percutaneous RFA for the treatment of a single nodular hepatic tumor that abutted the diaphragm from July 2000 to December 2006. All patients underwent ultrasound-guided RFA using internally cooled electrodes. A single ablation for 12 minutes was applied using 3-cm active-tip electrodes. We divided patients into two groups on the basis of whether artificial ascites was introduced before RFA: Group A consisted of patients who received artificial ascites with a mean of 760 mL of a 5% dextrose in water solution (n = 15) and group B consisted of patients who did not receive artificial ascites (n = 13). The volume of the ablation zone was measured on CT images obtained immediately after the ablation procedure, and imaging findings were compared for both groups using the Student's t test. We also compared the local tumor progression rate between both groups using the chi-square test (mean follow-up, 37.4 months). There was no significant difference between the two patient groups with regard to age, sex, Child-Pugh class, or tumor location (p > 0.05). The tumors were significantly smaller in group A patients (mean +/- SD, 1.6 +/- 0.5 cm) than in group B patients (2.1 +/- 0.7 cm) (p = 0.019). The mean volume of the RFA zone was 31.6 +/- 11.9 cm(3) in group A patients and 30.9 +/- 11.0 cm(3) in group B patients. There was no significant difference between the groups in the ablation volume (p = 0.871). Local tumor progression was noted in four patients (26.7%) in group A and in three patients (23.1%) in group B. There was no significant difference in the local tumor progression rate between the two groups (p = 0.83). Artificial ascites did not show a heat-sink effect on the volume of the ablation zone after percutaneous RFA for the

  17. Comparison of the Efficacy of Reoperation, Percutaneous Radiofrequency Thermocoagulation When Microvascular Decompression of Trigeminal Neuralgia Is Invalid.

    PubMed

    Zhang, Xin; Zhao, Hua; Tang, Yinda; Zhu, Jin; Wang, Xuhui; Li, Shiting

    2016-10-01

    To compare the curative effect of reoperation in short-term and percutaneous radiofrequency thermocoagulation (PRT) when trigeminal neuralgia patient after microvascular decompression (MVD) is invalid. Follow-up of 54 patients (30 patients with reoperation in the short term, 24 patients with PRT of primitive trigeminal neuralgia) when MVD is invalid between January 2008 and December 2014. To evaluate the degree of pain relief and facial numbness of patients after the treatment in short-term (1 month), in long-term (1 year). One month after surgery, the authors compared the reoperation group with PRT group. The ratio of cure rate P = 0.02, the ratio of effective rate P = 0.04, the ratio of facial numbness P = 0.01; 1 year after surgery, the authors compared the reoperation group with PRT group. The ratio of cure rate P = 0.004, the ratio of effective rate P = 0.006, the ratio of facial numbness P = 0.02, the ratio of recurrence P = 0.04. The short-term and long-term clinical efficacy in reoperation group was better than PRT group (P < 0.05). For the patients of trigeminal neuralgia when first MVD is invalid, reoperation is better than PRT, and a significantly lower incidence of facial numbness and recurrence than PRT.

  18. Midsubstance Tendinopathy, Percutaneous Techniques (Platelet-Rich Plasma, Extracorporeal Shock Wave Therapy, Prolotherapy, Radiofrequency Ablation).

    PubMed

    Smith, William Bret; Melton, Will; Davies, James

    2017-04-01

    The focus of this article is to present the current options available for noninvasive and percutaneous treatment options for noninsertional Achilles tendinopathy. An attempt is made to offer recommendations for both the treatment techniques as well as postprocedure protocols to be considered. Additionally, because there are numerous treatment options in this category, the different techniques are summarized in a chart format with a short list of pros and cons as well as the levels of evidence in the literature to support the different modalities. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Percutaneous computed tomography-guided radiofrequency thermal ablation of small unresectable lung tumours.

    PubMed

    Rossi, S; Dore, R; Cascina, A; Vespro, V; Garbagnati, F; Rosa, L; Ravetta, V; Azzaretti, A; Di Tolla, P; Orlandoni, G; Pozzi, E

    2006-03-01

    The aim of the current study was to evaluate the safety and the efficacy of radiofrequency thermal ablation (RFTA) for the treatment of nonsmall cell lung cancer (NSCLC) and isolated pulmonary metastases (METs) from colorectal cancer (CRC). A total of 31 patients (15 with NSCLCs and 16 with CRC lung METs), with 36 lung tumour nodules (mean+/-sd diameter: 22+/-8 mm, range: 10-35 mm) underwent computed tomography (CT)-guided RFTA using expandable electrodes. Contrast-enhanced CT was performed before and after (immediately and 30+/-5 days) each RFTA session to assess immediate results and complications and repeated 3 and 6 months post-RFTA, as well as every 6 months thereafter, to evaluate long-term results. Complete radiological necrosis was defined as a nonenhancing area at the tumour site that was equal to or larger than the treated tumour; persistence of enhancement at the tumour site indicated incomplete treatment. Local recurrence was defined as an increase in tumour size and/or enhancing tissue at the tumour site. Complete radiological necrosis of the 36 tumours was achieved with 39 RFTA sessions and 42 electrode insertions. No major complications or deaths were observed. Six patients experienced mild-to-moderate pain during the procedure. There were five cases of pneumothorax, none requiring drainage and four cases of pneumonia, which were successfully treated with antibiotics. After a mean follow-up of 11.4+/-7.7 months (range of 3-36 months), the overall local recurrence rate was 13.9% (20 and 9.5% for NSCLC and CRC-METs patients, respectively). Nineteen of the 31 (61.3%) patients were alive (15 apparently disease free) and 12 (38.7%) had died (three from causes unrelated to their cancer). Radiofrequency thermal ablation seems to be a safe, effective method for producing complete ablation of small nonsmall cell lung cancers and pulmonary colorectal cancer metastases.

  20. Treatment of hepatocellular carcinoma using percutaneous radiofrequency thermoablation: results and outcomes in 56 patients.

    PubMed

    Giovannini, Marc; Moutardier, Vincent; Danisi, Carcline; Bories, Erwan; Pesenti, Christian; Delpéro, Jean-Robert

    2003-01-01

    The aim of this study was to evaluate the efficacy of and tolerance for radiofrequency thermoablation (RFTA) in patients with hepatocellular carcinoma (HCC). From March 1999 to September 2001, a total of 56 patients (46 men and 10 women) whose mean age was 67.8 years (range 51 to 76 years) underwent RFTA for 71 HCCs at our institution. RFTA was carried out in 45 patients with one lesion less than 6 cm in diameter, in seven patients with two lesions less than 4 cm in diameter each, and in four patients with three lesions less than 3 cm in diameter each. The mean diameter of the lesions was 4.1 cm (range 0.8 to 6.0 cm). The etiology of the cirrhosis was alcoholism in 31 patients, post-hepatitis C in 19 patients, post-hepatitis B in four patients, and hemochromatosis in two patients. Forty-five patients were classified as Child stage A and 11 were Child stage B. No ascites, prothrombin time >60%, and platelet count <60,000/mm(3) were needed. Two types of cooled needles were used depending on the size of the lesion (a needle 15 cm in length was used for 2 or 3 cm tumors, and a cluster of needles was used for tumors larger than 4 cm). Helical computed tomography was performed 8 weeks after treatment. The main criterion for a complete response was the presence of a hypodense lesion without contrast enhancement. Mean follow-up was 14 months. Complete tumor destruction was achieved in 50 (89.2%) of 56 patients after one session and in 52 (92.8%) of 56 after two sessions. Twelve months later, a complete response was confirmed in 45 patients (80.3%), four patients had a local recurrence and new liver nodules, and three patients had died (one of bone metastasis, one of acute alcoholic hepatitis, and one of bronchial carcinoma). Thirty-nine patients (69.6%) were still in complete remission 36 months later, and a new HCC had developed in six patients. At 36 months 49 of 56 patients were alive and 39 of 56 were free of disease. Patients with HCCs that developed following viral

  1. Percutaneous Radiofrequency Ablation of Colorectal Cancer Liver Metastases: Factors Affecting Outcomes—A 10-year Experience at a Single Center

    PubMed Central

    Shady, Waleed; Petre, Elena N.; Gonen, Mithat; Erinjeri, Joseph P.; Brown, Karen T.; Covey, Anne M.; Alago, William; Durack, Jeremy C.; Maybody, Majid; Brody, Lynn A.; Siegelbaum, Robert H.; D’Angelica, Michael I.; Jarnagin, William R.; Solomon, Stephen B.; Kemeny, Nancy E.

    2016-01-01

    Purpose To identify predictors of oncologic outcomes after percutaneous radiofrequency ablation (RFA) of colorectal cancer liver metastases (CLMs) and to describe and evaluate a modified clinical risk score (CRS) adapted for ablation as a patient stratification and prognostic tool. Materials and Methods This study consisted of a HIPAA-compliant institutional review board–approved retrospective review of data in 162 patients with 233 CLMs treated with percutaneous RFA between December 2002 and December 2012. Contrast material–enhanced CT was used to assess technique effectiveness 4–8 weeks after RFA. Patients were followed up with contrast-enhanced CT every 2–4 months. Overall survival (OS) and local tumor progression–free survival (LTPFS) were calculated from the time of RFA by using the Kaplan-Meier method. Log-rank tests and Cox regression models were used for univariate and multivariate analysis to identify predictors of outcomes. Results Technique effectiveness was 94% (218 of 233). Median LTPFS was 26 months. At univariate analysis, predictors of shorter LTPFS were tumor size greater than 3 cm (P < .001), ablation margin size of 5 mm or less (P < .001), high modified CRS (P = .009), male sex (P = .03), and no history of prior hepatectomy (P = .04) or hepatic arterial infusion chemotherapy (P = .01). At multivariate analysis, only tumor size greater than 3 cm (P = .01) and margin size of 5 mm or less (P < .001) were independent predictors of shorter LTPFS. Median and 5-year OS were 36 months and 31%. At univariate analysis, predictors of shorter OS were tumor size larger than 3 cm (P = .005), carcinoembryonic antigen level greater than 30 ng/mL (P = .003), high modified CRS (P = .02), and extrahepatic disease (EHD) (P < .001). At multivariate analysis, tumor size greater than 3 cm (P = .006) and more than one site of EHD (P < .001) were independent predictors of shorter OS. Conclusion Tumor size of less than 3 cm and ablation margins greater than 5 mm

  2. Percutaneous radiofrequency facet joint denervation with monitoring of compound muscle action potential of the multifidus muscle group for treating chronic low back pain: a preliminary report.

    PubMed

    Kanchiku, Tsukasa; Imajo, Yasuaki; Suzuki, Hidenori; Yoshida, Yuichiro; Nishida, Norihiro; Taguchi, Toshihiko

    2014-10-01

    A retrospective review. The aim of this study was to study the effectiveness of percutaneous radiofrequency neurotomy of facet joints by monitoring compound muscle action potentials (CMAPs) of the multifidus muscle group as an objective index of treatment efficacy. Percutaneous radiofrequency neurotomy of the medial branches of the dorsal rami of the lumbar nerves is a widely accepted treatment for chronic lumbar intervertebral joint pain. However, its success rate has varied in different studies because an objective method for evaluating the facet joint denervation is lacking. Fifty-five patients (age range, 19-76 y; mean age, 55 y) with low back pain persisting for ≥3 months, in whom facet block and/or block of the medial branch of the dorsal ramus were only temporarily effective, were included. The Japanese Orthopaedic Association (JOA) scoring system for back pain was used for clinical assessment. JOA scores were measured before treatment and 1 week, 3 months, 6 months, and 12 months afterward. The improvement rate was calculated with ≥40% improvement rate defined as successful, and the success rate was subsequently evaluated. The patient success rate was 75% (41/55) at 1 week, 71% (39/55) at 3 months, 60% (33/55) at 6 months, and 51% (28/55) at 12 months after treatment. Two cases had minor postoperative complications, which were localized burning pain lasting <1 week at the site of electrode insertion. Our results suggest that percutaneous radiofrequency facet joint denervation with CMAPs monitoring is a safe, long-lasting, and effective treatment for chronic facet joint pain. CMAP monitoring may be useful as an objective index for facet denervation.

  3. Percutaneous Renal Tumor Ablation: Radiation Exposure During Cryoablation and Radiofrequency Ablation

    SciTech Connect

    McEachen, James C.; Leng, Shuai; Atwell, Thomas D.; Tollefson, Matthew K.; Friese, Jeremy L.; Wang, Zhen; Murad, M. Hassan; Schmit, Grant D.

    2016-02-15

    IntroductionOnce reserved solely for non-surgical cases, percutaneous ablation is becoming an increasingly popular treatment option for a wider array of patients with small renal masses and the radiation risk needs to be better defined as this transition continues.Materials and MethodsRetrospective review of our renal tumor ablation database revealed 425 patients who underwent percutaneous ablation for treatment of 455 renal tumors over a 5-year time period. Imparted radiation dose information was reviewed for each procedure and converted to effective patient dose and skin dose using established techniques. Statistical analysis was performed with each ablative technique.ResultsFor the 331 cryoablation procedures, the mean DLP was 6987 mGycm (SD = 2861) resulting in a mean effective dose of 104.7 mSv (SD = 43.5) and the mean CTDI{sub vol} was 558 mGy (SD = 439) resulting in a mean skin dose of 563.2 mGy (SD = 344.1). For the 124 RFA procedures, the mean DLP was 3485 mGycm (SD = 1630) resulting in a mean effective dose of 50.3 mSv (SD = 24.0) and the mean CTDI{sub vol} was 232 mGy (SD = 149) resulting in a mean skin dose of 233.2 mGy (SD = 117.4). The difference in patient radiation exposure between the two renal ablation techniques was statistically significant (p < 0.001).ConclusionBoth cryoablation and RFA imparted an average skin dose that was well below the 2 Gy deterministic threshold for appreciable sequela. Renal tumor cryoablation resulted in a mean skin and effective radiation dose more than twice that for RFA. The radiation exposure for both renal tumor ablation techniques was at the high end of the medical imaging radiation dose spectrum.

  4. Percutaneous Radiofrequency Ablation and Transcatheter Arterial Chemoembolization for Hypervascular Hepatocellular Carcinoma: Rate and Risk Factors for Local Recurrence

    SciTech Connect

    Murakami, Tomonori Ishimaru, Hideki; Sakamoto, Ichiro; Uetani, Masataka; Matsuoka, Yohjiro; Daikoku, Manabu; Honda, Sumihisa; Koshiishi, Takeshi; Fujimoto, Toshifumi

    2007-07-15

    Purpose. To analyze local recurrence-free rates and risk factors for recurrence following percutaneous radiofrequency ablation (RFA) or transcatheter arterial chemoembolization (TACE) for hypervascular hepatocellular carcinoma (HCC). Methods. One hundred and nine nodules treated by RFA and 173 nodules treated by TACE were included. Hypovascular nodules were excluded from this study. Overall local recurrence-free rates of each treatment group were calculated using the Kaplan-Meier method. The independent risk factors of local recurrence and the hazard ratios were analyzed using Cox's proportional-hazards regression model. Based on the results of multivariate analyses, we classified HCC nodules into four subgroups: central nodules {<=}2 cm or >2 cm and peripheral nodules {<=}2 cm or >2 cm. The local recurrence-free rates of these subgroups for each treatment were also calculated. Results. The overall local recurrence-free rate was significantly higher in the RFA group than in the TACE group (p = 0.013). The 24-month local recurrence-free rates in the RFA and TACE groups were 60.0% and 48.9%, respectively. In the RFA group, the only significant risk factor for recurrence was tumor size >2 cm in greatest dimension. In the TACE group, a central location was the only significant risk factor for recurrence. In central nodules that were {<=}2 cm, the local recurrence-free rate was significantly higher in the RFA group than in the TACE group (p < 0.001). In the remaining three groups, there was no significant difference in local recurrence-free rate between the two treatment methods. Conclusion. A tumor diameter of >2 cm was the only independent risk factor for local recurrence in RFA treatment, and a central location was the only independent risk factor in TACE treatment. Central lesions measuring {<=}2 cm should be treated by RFA.

  5. A preliminary study of the safety and efficacy of radiofrequency ablation with percutaneous kyphoplasty for thoracolumbar vertebral metastatic tumor treatment

    PubMed Central

    Zheng, Longpo; Chen, Zhengqi; Sun, Mengxiong; Zeng, Hui; Zuo, Dongqing; Hua, Yingqi; Cai, Zhengdong

    2014-01-01

    Background Thoracolumbar vertebral metastasis (TVM) affects a large number of cancer patients. However, safe and effective palliative care remains controversial. The aim of the present study was to investigate the safety and efficacy of minimally invasive image-guided radiofrequency ablation (RFA) with percutaneous kyphoplasty (PKP) for TVM treatment. Material/Methods A retrospective study of 26 patients (mean age: 59.31±11.62 years) was conducted, including 38 vertebral metastases at T11, T12, L1, L2, L3, L4, L5, and S1 with abundant blood vessels. Patients underwent RFA with PKP (4–6 min, 95±5°C, 150 W, effective electrode area of 1.5–2.0 cm) under general anesthesia from February 2005 to January 2009. Electrodes were inserted into the lesions and pre- and post-operative visual analog scale (VAS) scores and X-rays were collected on day 3, week 1, and months 1, 3, and 6. Tumor recurrence and pain level were also evaluated. Safety assessment was conducted based on complications and adverse events. The mean follow-up time was 8.4±2.1 months. Results A mean of 2.69±0.93 ablation was performed per patient. The ablation procedure required a mean of 15.08±4.64 min, while the injection of bone cement required a mean of 6.73±0.83 min, for a mean total operating time of 47.77±7.13 min. Postoperative VAS scores were significantly lower on day 3, week 1, and months 1, 3, and 6 (P<0.01), without any complications or tumor recurrence. Conclusions Image-guided RFA with PKP was safe and effective for TVM treatment when used with careful consideration of bone cement volume/viscosity, injection location, and temperature. PMID:24699431

  6. Percutaneous trigeminal ganglion radiofrequency thermocoagulation alleviates anxiety and depression disorders in patients with classic trigeminal neuralgia: A cohort study.

    PubMed

    Tang, YuanZhang; Ma, Ling; Li, Na; Guo, Yuna; Yang, Liqiang; Wu, Baishan; Yue, Jianning; Wang, Qi; Liu, Jingjie; Ni, Jia-Xiang

    2016-12-01

    Trigeminal neuralgia (TN) is a neurological condition that presents as excruciating facial pain. Depression and anxiety are commonly associated with TN; however, anxiety and depression disorders in patients with TN and the effects of the various therapeutic strategies for TN on these disorders are not well studied.To evaluate depression and anxiety in patients with trigeminal neuralgia (TN), identify factors that predict their occurrence and study the effect of the percutaneous trigeminal ganglion radiofrequency thermocoagulation (PRT) procedure for alleviating pain on depression and anxiety.Patients with classic TN, who received PRT treatment, were consecutively recruited between October 2014 and October 2015. Severity of pain was determined using the visual analogue scale (VAS) score. Beck Depression Inventory-II (BDI) and Beck anxiety Inventory (BAI) were used to evaluate depression and anxiety disorders pre- and post-PRT. Medical, demographic, and psychosocial backgrounds were also assessed as predictive factors. A BDI score of ≥14 represented depression and BAI score of ≥45 represented anxiety. VAS, BDI, and BAI scores were collected at the time of admission and on the day of discharge.Of the 167 patients who participated in the study, 121 (72.5%) had depression and 34 (20.4%) suffered anxiety. Pre-PRT procedure, female sex, age >50 years, ineffective treatment, and high pain intensity (VAS ≥7) predicted the development of depression and anxiety. Post-PRT procedure, all patients who experienced pain relief also reported amelioration of depression and anxiety.A considerable percentage of patients with TN developed depression and anxiety. Patients who were female, older than 50 years, or suffered from failure treatment and severe pain (VAS>7), were at higher risk of depression and anxiety development. Complete alleviation of pain by using surgical PRT could immediately attenuate depressive and anxiety disorders associated with TN.

  7. [Examination of percutaneous microwave coagulation and radiofrequency ablation therapy for metastatic liver cancer].

    PubMed

    Ohkawa, Shinichi; Hirokawa, Satoru; Masaki, Takahiro; Miyakawa, Kaoru; Tarao, Kazuo; Akaike, Makoto; Sugimasa, Yukio; Takemiya, Shoji; Sairenji, Motonori; Motohashi, Hisahiko

    2002-11-01

    Percutaneous microwave coagulation therapy (PMCT) and radio frequency ablation therapy (RFA) as treatments for metastatic liver cancer were examined. PMCT or RFA was administered for 18 metastatic liver cancer lesions (primary lesion: 11 colon rectal cancer, one esophagus cancer, one thyroid cancer, one pancreatic cancer, one pheochromocytoma) in 16 patients from July 1999 to March 2002. RFA was performed 1 time for 12 minutes in principle, using a Cool-tip RF system from Radionics. Patients had a mean age of 58.8 years and the mean diameter of the neoplasms was about 22 mm. Critical complications were not seen. The rate of partial recurrence was 35.3% as of March, 2002, in an average observation period of 7.3 months. On the other hand, with the medical treatment for the hepatocellular carcinoma provided during this period, the rate of partial recurrence was 14.8%. The treatment of metastatic liver cancer by PMCT and RFA is associated with a high rate of a recurrence as compared with hepatocellular carcinoma, and needs to be examined to discover ways of adaptation and improvement of the technology.

  8. Lung Tumors Treated With Percutaneous Radiofrequency Ablation: Computed Tomography Imaging Follow-Up

    SciTech Connect

    Palussiere, Jean Marcet, Benjamin; Descat, Edouard; Deschamps, Frederic; Rao, Pramod; Ravaud, Alain; Brouste, Veronique; Baere, Thierry de

    2011-10-15

    Purpose: To describe the morphologic evolution of lung tumors treated with radiofrequency ablation (RFA) by way of computed tomography (CT) images and to investigate patterns of incomplete RFA at the site of ablation. Materials and Methods: One hundred eighty-nine patients with 350 lung tumors treated with RFA underwent CT imaging at 2, 4, 6, and 12 months. CT findings were interpreted separately by two reviewers with consensus. Five different radiologic patterns were predefined: fibrosis, cavitation, nodule, atelectasis, and disappearance. The appearance of the treated area was evaluated at each follow-up CT using the predefined patterns. Results: At 1 year after treatment, the most common evolutions were fibrosis (50.5%) or nodules (44.8%). Differences were noted depending on the initial size of the tumor, with fibrosis occurring more frequently for tumors <2 cm (58.6% vs. 22.9%, P = 1 Multiplication-Sign 10{sup -5}). Cavitation and atelectasis were less frequent patterns (2.4% and 1.4%, respectively, at 1 year). Tumor location (intraparenchymatous, with pleural contact <50% or >50%) was not significantly correlated with follow-up image pattern. Local tumor progressions were observed with each type of evolution. At 1 year, 12 local recurrences were noted: 2 cavitations, which represented 40% of the cavitations noted at 1 year; 2 fibroses (1.9%); 7 nodules (7.4%); and 1 atelectasis (33.3%). Conclusion: After RFA of lung tumors, follow-up CT scans show that the shape of the treatment zone can evolve in five different patterns. None of these patterns, however, can confirm the absence of further local tumor progression at subsequent follow-up.

  9. Prospective study of a 'popping' sound during percutaneous radiofrequency ablation for hepatocellular carcinoma.

    PubMed

    Fernandes, Mark Lee; Lin, Chen-Chun; Lin, Chun-Jung; Chen, Wei-Ting; Lin, Shi-Ming

    2010-02-01

    To prospectively evaluate the occurrence of a 'popping' sound during radiofrequency (RF) ablation for hepatocellular carcinoma (HCC) and its association with early tumor progression and patient survival. Seventy-six patients with 100 tumors underwent RF ablation by using an internally cooled electrode. A popping sound was defined as an audible sound or tactile vibration detected by the operator during RF ablation. Follow-up ranged from 6 to 38 months (mean, 19 months) and included 3-6 month ultrasonography, serum alpha-fetoprotein measurements, and computed tomography or magnetic resonance imaging. Early local and distant intrahepatic tumor progression within 12 months and survival were analyzed. A popping sound occurred during 58 of the 100 (58%) tumor ablations. Primary technique effectiveness was achieved in 97 of the 100 (97%) tumors. Major complications occurred in 2 of the 76 patients (2.6%). The cumulative rate of early local tumor progression was 20.8%. At multivariate analysis, early local tumor progression was associated with tumor size larger than 3 cm (odds ratio [OR] = 4.08, P = .012) and inversely associated with a popping sound (OR = 0.267, P = .026). The cumulative rate of early distant intrahepatic tumor progression was 21.4%, and the cumulative survival of the whole cohort at 6, 12, 18, and 24 months was 98.7%, 96%, 92.7%, and 83.6%, respectively. A popping sound was not significantly associated with either early distant intrahepatic tumor progression (P = .341) or patient survival (P = .975). A popping sound during RF ablation is not associated with an increased risk of early tumor progression or poorer patient survival. Copyright (c) 2010 SIR. Published by Elsevier Inc. All rights reserved.

  10. Percutaneous Dual-Switching Monopolar Radiofrequency Ablation Using a Separable Clustered Electrode: A Preliminary Study

    PubMed Central

    Choi, Tae Won; Lee, Dong Ho; Lee, Jeong-Hoon; Yu, Su Jong; Kim, Yoon Jun; Yoon, Jung-Hwan; Han, Joon Koo

    2017-01-01

    Objective To prospectively evaluate the safety and therapeutic effectiveness of dual-switching monopolar (DSM) radiofrequency ablation (RFA) for the treatment of hepatocellular carcinoma (HCC), and to retrospectively compare the results with those of single-switching monopolar (SSM) RFA in a historical control group. Materials and Methods This study was approved by the Institutional Review Board, with informed consent obtained from all patients. Fifty-two HCC patients who underwent DSM-RFA using a separable clustered electrode and dual-generators were prospectively enrolled. Technical parameters, complications, technical success, technical effectiveness, and local tumor progression (LTP) rates were evaluated by means of post-procedural and follow-up imaging. Thereafter, the outcome of DSM-RFA was compared with those of 249 retrospectively included HCC patients treated with SSM-RFA. Results There were two major complications (3.8%, 2/52) including pleural and pericardial effusion in the DSM-RFA group. The DSM-RFA yielded a 100% technical success rate, a 98.1% technical effectiveness rate, and a 4.3% 2-year LTP rate. In a retrospective comparison between the two groups, DSM-RFA created significantly larger ablation volume (4.20 ± 2.07 cm3/min vs. 3.03 ± 1.99 cm3/min, p < 0.01), and delivered higher energy (1.43 ± 0.37 kcal/min vs. 1.25 ± 0.50 kcal/min, p < 0.01) per given time, than SSM-RFA. There was no significant difference in major procedure-related complications (3.8% vs. 4.4%) and technical effectiveness rate (98.1% vs. 96.4%) between the two groups (p = 1.00). In addition, the 2-year LTP rate of DSM-RFA and SSM-RFA were 4.3% and 10.1%, respectively (p = 0.15). Conclusion DSM-RFA using a separable clustered electrode is safe and provides high local tumor control and good preliminary clinical outcome for small HCCs, which are at least comparable to those of SSM-RFA. PMID:28860897

  11. Radiofrequency Ablation and Percutaneous Ethanol Injection Treatment for Recurrent Local and Distant Well-Differentiated Thyroid Carcinoma

    PubMed Central

    Monchik, Jack M.; Donatini, Gianluca; Iannuccilli, Jason; Dupuy, Damian E.

    2006-01-01

    Objective: To assess the long-term efficacy of radiofrequency ablation (RFA) and percutaneous ethanol (EtOH) injection treatment of local recurrence or focal distant metastases of well-differentiated thyroid cancer (WTC). Background: RFA and EtOH injection techniques are new minimally invasive surgical alternatives for treatment of recurrent WTC. We report our experience and long-term follow-up results using RFA or EtOH ablation in treating local recurrence and distant focal metastases from WTC. Methods: Twenty patients underwent treatment of biopsy-proven recurrent WTC in the neck. Sixteen of these patients had lesions treated by ultrasound-guided RFA (mean size, 17.0 mm; range, 8–40 mm), while 6 had ultrasound-guided EtOH injection treatment (mean size, 11.4 mm; range, 6–15 mm). Four patients underwent RFA treatment of focal distant metastases from WTC. Three of these patients had CT-guided RFA of bone metastases (mean size, 40.0 mm; range, 30–60 mm), and 1 patient underwent RFA for a solitary lung metastasis (size, 27 mm). Patients were then followed with routine ultrasound, 131I whole body scan, and/or serum thyroglobulin levels for recurrence at the treatment site. Results: No recurrent disease was detected at the treatment site in 14 of the 16 patients treated with RFA and in all 6 patients treated with EtOH injection at a mean follow-up of 40.7 and 18.7 months, respectively. Two of the 3 patients treated for bone metastases are free of disease at the treatment site at 44 and 53 months of follow-up, respectively. The patient who underwent RFA for a solitary lung metastasis is free of disease at the treatment site at 10 months of follow-up. No complications were experienced in the group treated by EtOH injection, while 1 minor skin burn and 1 permanent vocal cord paralysis occurred in the RFA treatment group. Conclusions: RFA and EtOH ablation show promise as alternatives to surgical treatment of recurrent WTC in patients with difficult reoperations

  12. Percutaneous Intraductal Radiofrequency Ablation Combined with Biliary Stent Placement for Nonresectable Malignant Biliary Obstruction Improves Stent Patency but not Survival

    PubMed Central

    Wang, Jianfeng; Zhao, Lizhen; Zhou, Chuanguo; Gao, Kun; Huang, Qiang; Wei, Baojie; Gao, Jun

    2016-01-01

    Abstract Although radiofrequency (RF) ablation has been accepted as a curative treatment modality for solid organ tumors, intraductal RF ablation for malignant biliary obstruction has not been widely described. The aim of this study was to evaluate the feasibility, safety, and efficacy (in terms of stent patency and survival) of intraductal RF ablation combined with biliary stent placement for nonresectable malignant biliary obstruction. A search of the nonresectable malignant extrahepatic biliary obstruction database (179 patients) identified 18 consecutive patients who were treated with biliary intraluminal RF ablation during percutaneous transhepatic cholangiodrainage and inner stent placement (RF ablation group) and 18 patients who underwent inner stent placement without biliary intraluminal RF ablation (control group). The patients were matched for tumor type, location of obstruction, tumor stage, and Child–Pugh class status. Primary endpoints included safety, stent patency time, and survival rates. The secondary endpoint was effectiveness of the technique. The RF ablation and control groups were closely matched in terms of age, diagnosis, presence of metastases, presence of locally advanced tumor, American Society of Anesthesiologists (ASA) grade, and chemotherapy regimen (all P > 0.05). The technical success rate for both groups was 100%. The median time of stent patency in the RF ablation and control groups were 5.8 (2.8–11.5) months and 4.5 (2.4–8.0) months, respectively (Kaplan–Meier analysis: P = 0.03). The median survival times in the RF ablation and control groups were 6.1 (4.8–15.2) months and 5.8 (4.2–16.5) months, with no significant difference according to Kaplan–Meier analysis (P = 0.45). In univariate and multivariate analyses, poorer overall survival was associated with advanced age and presence of metastases (P < 0.05). Intraductal RF ablation combined with biliary stent placement for nonresectable malignant

  13. Percutaneous treatment of patients with heart diseases: selection, guidance and follow-up. A review

    PubMed Central

    2012-01-01

    Aortic stenosis and mitral regurgitation, patent foramen ovale, interatrial septal defect, atrial fibrillation and perivalvular leak, are now amenable to percutaneous treatment. These percutaneous procedures require the use of Transthoracic (TTE), Transesophageal (TEE) and/or Intracardiac echocardiography (ICE). This paper provides an overview of the different percutaneous interventions, trying to provide a systematic and comprehensive approach for selection, guidance and follow-up of patients undergoing these procedures, illustrating the key role of 2D echocardiography. PMID:22452829

  14. Treatment Failure After Image-Guided Percutaneous Radiofrequency Ablation (RFA) of Renal Tumors - A Systematic Review with Description of Type, Frequency, Risk Factors and Management.

    PubMed

    Vollherbst, Dominik; Bertheau, Robert; Kauczor, Hans-Ulrich; Radeleff, Boris Alexis; Pereira, Philippe L; Sommer, Christof-Matthias

    2017-03-01

    Background Radiofrequency ablation (RFA) is an established treatment for small renal tumors. The objective of this review is to systematically assess the type, frequency, risk factors and management of treatment failure after image-guided percutaneous RFA of renal tumors. Method 10 studies (967 patients, 1033 tumors) with a mean/median follow-up of ≥ 30 months were systematically identified and analyzed. Results and Conclusion Image-guided percutaneous RFA of localized renal tumors is very effective. The most common type of treatment failure is residual unablated tumor (5.9 %), followed by local tumor progression (4.7 %). De novo tumors in the kidneys occur in 1.3 % of cases and extra-renal metastases in 2.0 %. Local tumor progression, de novo tumors in the kidneys and extra-renal metastases occur predominantly later than 12 months after initial RFA. Tumor size > 3 cm and central tumor location are the major risk factors for treatment failure. In the case of treatment failure, repeated RFA shows high success rates (86.3 % for residual unablated tumors and 87.5 % for local tumor progression). Key Points: · Treatment failure can be subdivided into residual unablated tumor and local tumor progression.. · Residual unablated tumor occurs in 5.9 % of cases.. · Local tumor progression occurs in 4.7 % of cases.. · Tumor size and location are the major risk factors for treatment failure.. · Repeated RFA is effective and commonly used for management.. Citation Format · Vollherbst D, Bertheau R, Kauczor H et al. Treatment Failure After Image-Guided Percutaneous Radiofrequency Ablation (RFA) of Renal Tumors - A Systematic Review with Description of Type, Frequency, Risk Factors and Management. Fortschr Röntgenstr 2017; 189: 219 - 227.

  15. Radiofrequency ablation and percutaneous permanent iodine-125 implantation as salvage therapy for giant recurrent sclerosing epithelioid fibrosarcoma of the chest wall: A case report

    PubMed Central

    KE, SHAN; DING, XUE-MEI; GAO, JUN; WANG, SHAO-HONG; ZHANG, JUN; KONG, JIAN; SUN, WEN-BING

    2015-01-01

    Sclerosing epithelioid fibrosarcoma (SEF) is a rare soft-tissue sarcoma for which there is no standardized treatment regimen available. The current treatment options for SEF are resection, radiation and chemotherapy. Surgical resection remains the mainstay of therapy for SEF. However, SEF is an aggressive tumor that is prone to repeated local recurrence if not widely excised. Radiation and chemotherapy are less commonly used due to the insensitivity of SEF to these therapies. The treatment of recurrent SEF is even more challenging. The present study describes a patient who presented with a giant recurrent SEF arising from the chest wall that was accompanied by emergent bleeding. The patient was a 70-year-old male who had multiple comorbid diseases, including hypertension and chronic cardiac dysfunction. A computed tomography (CT) scan indicated the involvement of the sternum and anterior mediastinum. However, the patient refused any further surgery. Subsequent to careful discussion and consideration, radiofrequency (RF) ablation and percutaneous iodine-125 implantation was administered. The emergent bleeding was successfully stopped and the tumor was eliminated using RF ablation. Percutaneous iodine-125 implantation under CT guidance established effective control on the growth of the tumor involving the mediastinum. Despite this, the tumor recurred 6 months after treatment. The patient refused any further treatment and was discharged. In conclusion, RF ablation and percutaneous permanent iodine-125 implantation is a feasible and safe salvage therapy for patients with recurrent SEF of the chest wall. PMID:26137032

  16. [Percutaneous thermoablation of pulmonary metastases. Experience with the application of laser-induced thermotherapy (LITT) and radiofrequency ablation (RFA), and a literature review].

    PubMed

    Vogl, T J; Straub, R; Lehnert, T; Eichler, K; Lüder-Lühr, T; Peters, J; Zangos, S; Söllner, O; Mack, M

    2004-11-01

    Evaluation of technical aspects, local efficiency and complications of thermoablative procedures, such as radiofrequency ablation (RFA) and laser-induced thermotherapy (LITT), in percutaneous lung metastases. Techniques of thermal ablative procedures of RFA and LITT are presented. For primary positioning, monitoring and therapy control, computed tomography (CT) or magnetic resonance imaging (MRI) was performed. Different monopolar systems and one bipolar system were available for RFA and two different cooling systems for LITT. Percutaneous CT-guided RFA was performed on 32 metastases in 20 patients and percutaneous LITT on 34 metastases in 24 patients. Inclusion criteria were metastases < or = 5 cm in diameter in unresectable patients with up to 3 metastases per lung. All treatments were performed on outpatient basis using analgosedation. In our patient group, all patients tolerated both the RFA and LITT procedures well with mild sedation. The pneumothorax rate was 15 % (5/32 procedures) for the RFA group and 12 % (4/34 procedures) for the LITT group, without insertion of a chest tube. In all RF ablations, a complete "roll off" (increase in impedance) was achieved. Local tumor control rate in the 6-month follow-up was 85 % for RFA and 91 % for LITT. Nineteen of the 20 patients treated are still alive, one patient died from tumor progression. Both pulmonary RFA and LITT allow safe thermal ablation of pulmon arg metastases with a low complication rate and an acceptable tumor control rate.

  17. [Newborn outcomes after radiofrequency ablation for selective reduction in the complicated monochorionic pregnancies].

    PubMed

    Panciatici, M; Tosello, B; Blanc, J; Haumonté, J-B; D'Ercole, C; Gire, C

    2017-04-01

    To describe perinatal data and to evaluate the neonatal neurological outcome of monochorionic twin pregnancies with selective termination by radiofrequency ablation. Retrospective data of perinatal data for nine consecutive monochorionic pregnancies eligible for radiofrequency ablation from January 2013 to August 2015 were collected. A prospective observational study of the neurological outcome of nine children was conducted using the Ages & Stages Questionnaire (ASQ), 2nd edition, French version, adapted to the age. The radiofrequency procedures were performed at a mean gestational age (GA) of 21.4 weeks (±7 weeks). The indications for a selective interruption of a pregnancy were: acardiac twin (n=4), brain malformation (n=1), severe intrauterine growth restriction (IUGR) with massive cerebral ischemia in the context of twin-twin transfusion syndrome grade III (n=1), severe selective IUGR associated with a polymalformative syndrome (n=1) and severe selective IUGR (n=2). The mean GA at birth was 36.7 weeks GA (±3.8 weeks). No infant showed neurological neonatal morbidity. Any ASQ area explored was pathological (<-2SD) for the nine children (mean age at follow-up [±SD], 14.8 months [±8.8 months]). This work constitutes a preliminary study for developing long-term follow-up and early care programs for those children born subsequent to a radiofrequency ablation for selective reduction. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  18. Metal contents of liver parenchyma after percutaneous ethanol injection or radiofrequency ablation in patients with hepatocellular carcinoma before and after trientine hydrochloride therapy.

    PubMed

    Fukuda, Hiroyuki; Ebara, Masaaki; Okabe, Shinichiro; Yoshikawa, Masaharu; Sugiura, Nobuyuki; Saisho, Hiromitsu; Kondo, Fukuo; Yukawa, Masae

    2004-06-01

    We administered trientine hydrochloride, a drug used in the treatment of Wilson's disease, to patients with hepatocellular carcinoma after radical treatment with percutaneous ethanol injection or radiofrequency ablation, and examined its effect on the reduction of liver-tissue copper content. We enrolled 24 patients with 3 or fewer primary lesions of Child class A or B hepatocellular carcinoma with diameters of 3 cm or less who had undergone radical treatment with percutaneous ethanol injection or radiofrequency ablation. Trientine hydrochloride was orally administered in a single daily dose of 250 mg to 12 patients before a meal (at fasting, group 1) or at a total daily dosage of 750 mg, divided into 3 doses, to 12 patients (group 2). This study was a randomized between-groups comparative study of 12 weeks' duration. We used the particle-induced x-ray-emission method to determine liver-tissue mineral content. Urine copper and serum mineral levels were also measured, and transaminase levels were examined. Liver-tissue copper content decreased significantly, to 160.1 microg/g dry weight, after treatment, compared with the pretreatment level of 306.8 microg/g dry weight (P <.05). We detected no significant difference in iron or zinc content before and after treatment. The copper content was significantly reduced after treatment in both groups (P <.05). The urine copper level was significantly increased after 1 week of treatment but decreased thereafter. Serum copper levels were significantly reduced after treatment (P <.01). We detected no significant difference in transaminase level before and after treatment. Iron-deficiency anemia in 1 patient after 12 weeks' treatment was the only adverse reaction, and it was improved by the administration of an iron product. We noted no other overt adverse reactions. In patients with hepatocellular carcinoma, trientine hydrochloride therapy may significantly reduce copper content in liver tissue.

  19. Temporary Percutaneous Instrumentation and Selective Anterior Fusion for Thoracolumbar Fractures.

    PubMed

    Charles, Yann Philippe; Walter, Axel; Schuller, Sébastien; Steib, Jean-Paul

    2017-05-01

    Prospective clinical trial in thoracolumbar trauma with 5-year follow-up. To analyze clinical and radiographic outcomes of minimal invasive surgery, and the rational of circumferential fracture treatment with regard to age, degenerative changes, bone mineral density, and global sagittal balance. Non-neurologic fractures with anterior column defect can be treated by posterior percutaneous instrumentation and selective anterior fusion. After consolidation, instrumentation can be removed at 1 year to provide mobility in non-fused segments. Fifty-one patients, 47 (18-75) years, were operated for A2, A3, or B-type fractures. Visual analog scale (VAS) for back pain and Oswestry Disability Index (ODI) were assessed. Radiographic measurements were: sagittal index, regional kyphosis, T4-T12 kyphosis, L1-S1 lordosis, pelvic incidence, pelvic tilt, sacral slope, and T9 tilt. Anterior fusion and facet joints were analyzed on computed tomography (CT) at 1 year. The ODI was 8.8 before accident, 35.4 at 3 months, 17.8 at 2 years, 14.4 at 5 years. The VAS was 2.0 at 3 months and 1.0 at 5 years. The sagittal index was 18.0° preoperatively and 1.0° at 3 months (P < 0.0001). A loss of reduction of 1.1° occurred after implant removal (P = 0.009). Global sagittal balance remained unchanged. Ten patients with osteopenia or osteoporosis had a worse ODI: 24.7 versus 11.9 (P = 0.016), and a greater loss of correction: 4.9° versus 1.3° (P = 0.007). Cages filled with cancellous bone from the fractured vertebra fused regularly. Spontaneous facet joint fusions were observed in two patients at the fracture level in B-type injuries. Percutaneous instrumentation and selective anterior fusion using autologous bone and mesh cages lead to high fusion rates, which provided good long-term clinical results in younger patients with thoracolumbar fractures. Sagittal alignment was maintained after instrumentation removal without damaging paravertebral muscles. Outcomes were worse in

  20. Percutaneous Radiofrequency Ablation of Osteoid Osteomas with Use of Real-Time Needle Guidance for Accurate Needle Placement: A Pilot Study

    SciTech Connect

    Busser, Wendy M. H. Hoogeveen, Yvonne L.; Veth, Rene P. H.; Schreuder, H. W. Bart; Balguid, Angelique; Renema, W. KlaasJan; SchultzeKool, Leo J.

    2011-02-15

    Purpose: To evaluate the accuracy and technical success of positioning a radiofrequency ablation (RFA) electrode in osteoid osteomas by use of a new real-time needle guidance technology combining cone-beam computed tomography (CT) and fluoroscopy. Materials and Methods: Percutaneous RFA of osteoid osteomas was performed in five patients (median age 18 years), under general anesthesia, with the use of cone-beam CT and fluoroscopic guidance for electrode positioning. The outcome parameters were technical success, meaning correct needle placement in the nidus; accuracy defined as the deviation (in mm) from the center of the nidus; and clinical outcome at follow-up. Results: In all five cases, positioning was possible within 3 mm of the determined target location (median nidus size 6.8 mm; range 5-10.2 mm). All procedures were technically successful. All patients were free of pain at clinical follow-up. No complications were observed. Conclusion: Real-time fluoroscopy needle guidance based on cone-beam CT is a useful tool to accurately position radiofrequency needles for minimally invasive treatment of osteoid osteomas.

  1. Treatment of renal tumors by percutaneous ultrasound-guided radiofrequency ablation using a multitined electrode: effectiveness and complications.

    PubMed

    del Cura, Jose L; Zabala, Rosa; Iriarte, Jose I; Unda, Miguel

    2010-03-01

    Radiofrequency ablation (RFA) is a minimally aggressive, therapeutic alternative for renal tumors. It can be an alternative to nephrectomy in patients with previous nephrectomy, bilateral tumors, von Hippel-Lindau disease, or small renal carcinomas and in those with contraindications for surgery. To assess the effectiveness of the treatment of renal tumors by RFA in the short and medium term and to identify the possible complications and the factors that determine therapeutic success. A retrospective review of patients with renal tumors treated with RFA between May 2005 and December 2008 was performed in a tertiary academic hospital. Patients were selected among those with previous nephrectomy, bilateral neoplasms, von Hippel-Lindau disease, surgical risk, comorbidity, advanced age, or patient's refusal to surgery. Tumors with evidence of extrarenal extension were excluded. Patients were followed up for 10-50 mo using computed tomography and magnetic resonance imaging. Ultrasound-guided RFA was performed on 65 tumors (range: 1.2-5.3 cm) of 58 patients using multitined electrodes. Incomplete ablation rate, therapeutic success rate, and complications rate. Therapeutic success was achieved in 59 of 65 tumors (91%): 53 in a single session, 5 in two sessions, and 1 in three sessions. A significant relationship was observed between size and growth pattern of the tumor and both therapeutic success and incomplete ablation rates. Therapeutic success in tumors >5 cm was 60%. Complications were detected in 10 patients (13%); 5% were considered major complications. Limitations include the lack of pathologic studies to confirm a complete ablation and the lack of a control group to compare with the results of those who underwent nephrectomy. RFA is safe and effective in renal tumors. Corticomedullary lesions and tumors >3 cm have greater possibility of incomplete ablation. In tumors >5 cm, RFA has a significant failure rate. 2009 European Association of Urology. Published by

  2. Energy Saving Glass Lamination via Selective Radio-Frequency Heating

    SciTech Connect

    Shulman, Holly S.; Allan, Shawn M.

    2009-11-11

    This Inventions and Innovations program supported the technical and commercial research and development needed to elevate Ceralink's energy saving process for flat glass lamination from bench scale to a self-supporting technology with significant potential for growth. Radio-frequency heating was any un-explored option for laminating glass prior to this program. With significant commercial success through time and energy savings in the wood, paper, and plastics industries, RF heating was found to have significant promise for the energy intensive glass lamination industry. A major technical goal of the program was to demonstrate RF lamination across a wide range of laminate sizes and materials. This was successfully accomplished, dispelling many skeptics' concerns about the abilities of the technology. Ceralink laminated panels up to 2 ft x 3 ft, with four sets processed simultaneously, in a 3 minute cycle. All major categories of interlayer materials were found to work with RF lamination. In addition to laminating glass, other materials including photovoltaic silicon solar cells, light emitting diodes, metallized glass, plastics (acrylic and polycarbonate), and ceramics (alumina) were found compatible with the RF process. This opens up a wide range of commercial opportunities beyond the initially targeted automotive industry. The dramatic energy savings reported for RF lamination at the bench scale were found to be maintained through the scale up of the process. Even at 2 ft x 3 ft panel sizes, energy savings are estimated to be at least 90% compared to autoclaving or vacuum lamination. With targeted promotion through conference presentations, press releases and internet presence, RF lamination has gained significant attention, drawing large audiences at American Ceramic Society meetings. The commercialization success of the project includes the establishment of a revenue-generating business model for providing process development and demonstrations for potential RF

  3. Does artificial ascites induce the heat-sink phenomenon during percutaneous radiofrequency ablation of the hepatic subcapsular area?: an in vivo experimental study using a rabbit model.

    PubMed

    Kim, Young Sun; Rhim, Hyunchul; Choi, Dongil; Lim, Hyo K

    2009-01-01

    To evaluate the effect of the heat-sink phenomenon induced by artificial ascites on the size of the ablation zone during percutaneous radiofrequency (RF) ablation of the hepatic subcapsular area in an in vivo rabbit model. A total of 21 percutaneous rabbit liver RF ablations were performed with and without artificial ascites (5% dextrose aqueous solution). The rabbits were divided into three groups: a) control group (C, n = 7); b) room temperature ascites group (R, n = 7); and c) warmed ascites group (W, n = 7). The tip of a 1 cm, internally cooled electrode was placed on the subcapsular region of the hepatic dome via ultrasound guidance, and ablation was continued for 6 min. Changes in temperature of the ascites were monitored during the ablation. The size of the ablation zones of the excised livers and immediate complications rates were compared statistically between the groups (Mann-Whitney U test, Kruskal-Wallis test, linear-by-linear association, p = 0.05). One rabbit from the "W" group expired during the procedure. In all groups, the ascites temperatures approached their respective body temperatures as the ablations continued; however, a significant difference in ascites temperature was found between groups "W" and "R" throughout the procedures (39.2+/-0.4 degrees C in group W and 33.4+/-4.3 degrees C in group R at 6 min, p = 0.003). No significant difference was found between the size of the ablation zones (782.4+/-237.3 mL in group C, 1,172.0+/-468.9 mL in group R, and 1,030.6+/-665.1 mL in group W, p = 0.170) for the excised liver specimens. Diaphragmatic injury was identified in three of seven cases (42.9%) upon visual inspection of group "C" rabbits (p = 0.030). Artificial ascites are not likely to cause a significant heat-sink phenomenon in the percutaneous RF ablation of the hepatic subcapsular region.

  4. Obstruction of the bypassed stomach treated with percutaneous drainage: an alternative treatment for selected cases.

    PubMed

    López-Tomassetti Fernández, E M; Arteaga González, I; Diaz-Luis, H; Carrillo Pallares, A

    2008-02-01

    Biliopancreatic limb obstruction in Roux-en-Y gastric bypass is an infrequent complication that should be recognized early to avoid the risk of peritonitis and death. In this manuscript, we report a case of acute gastric remnant dilatation secondary to intraabdominal hematoma provoked by trocar injury that was compressing the second portion of duodenum lumen. To treat this problem, we decided on a less invasive treatment consisting of percutaneous decompression of the stomach. The procedure was performed using sonographic guidance with local anesthesia, thus, avoiding a new surgical procedure. In this selected case, percutaneous radiological catheter placement provided an effective decompression of the excluded gastric remnant until spontaneous resolution of the obstruction.

  5. Effectiveness of Computed Tomography Guided Percutaneous Radiofrequency Ablation Therapy for Osteoid Osteoma: Initial Results and Review of the Literature

    PubMed Central

    Karagöz, Erdal; Özel, Deniz; Özkan, Fuat; Özel, Betül Duran; Özer, Özgur; Coşkun, Zafer Ünsal

    2016-01-01

    Summary Background The aim of this retrospective study is to determine our experience of technique success rate, complications and clinical results in long term follow up for computed tomography (CT)-guided radiofrequency ablation [RA] therapy for osteoid osteoma (OO). Material/Methods We performed RA therapy to 18 patients with OO referred to interventional radiology from other clinics primarily from orthopedics; between January 2011 to May 2014. Daytime and nighttime pain intensity of 18 patients was noted according to visual analog scale (VAS). After procedure pain intensity was compared with before one. We also discussed other factors can affect it. Results All procedures were completed technically successful for all patients [100%]. We did not experience any major complication or mortality. However we had 3 minor complications. Pain came back in 1 patient after 5 months from procedure and it was considered as recurrence. Dramatic pain intensity fall was seen in patients after procedure, both daytime and nighttime. However we did not find and statistically significant change in comparison of pain intensity reduce and time needed to return back to routine life when using patients demographic data and lesion size. Conclusions CT guided RA therapy of OO is minimally invasive, effective and secure procedure. PMID:27429671

  6. Hyaluronic Acid Gel Injection to Prevent Thermal Injury of Adjacent Gastrointestinal Tract during Percutaneous Liver Radiofrequency Ablation

    SciTech Connect

    Hasegawa, Takaaki Takaki, Haruyuki; Miyagi, Hideki; Nakatsuka, Atsuhiro; Uraki, Junji; Yamanaka, Takashi; Fujimori, Masashi; Sakuma, Hajime; Yamakado, Koichiro

    2013-08-01

    This study evaluated the safety, feasibility, and clinical utility of hyaluronic acid gel injection to separate the gastrointestinal tract from the tumor during liver radiofrequency ablation (RFA). Eleven patients with liver tumors measuring 0.9-3.5 cm (mean {+-} standard deviation, 2.1 {+-} 0.8 cm) that were adjacent to the gastrointestinal tracts received RFA after the mixture of hyaluronic acid gel and contrast material (volume, 26.4 {+-} 14.5 mL; range, 10-60 mL) was injected between the tumor and the gastrointestinal tract under computed tomographic-fluoroscopic guidance. Each tumor was separated from the gastrointestinal tract by 1.0-1.5 cm (distance, 1.2 {+-} 0.2 cm) after injection of hyaluronic acid gel, and subsequent RFA was performed without any complications in all patients. Although tumor enhancement disappeared in all patients, local tumor progression was found in a patient (9.1 %, 1 of 11) during the follow-up of 5.5 {+-} 3.2 months (range, 0.4-9.9 months). In conclusion, hyaluronic acid gel injection is a safe and useful technique to avoid thermal injury of the adjacent gastrointestinal tract during liver RFA.

  7. Hyaluronic acid gel injection to prevent thermal injury of adjacent gastrointestinal tract during percutaneous liver radiofrequency ablation.

    PubMed

    Hasegawa, Takaaki; Takaki, Haruyuki; Miyagi, Hideki; Nakatsuka, Atsuhiro; Uraki, Junji; Yamanaka, Takashi; Fujimori, Masashi; Sakuma, Hajime; Yamakado, Koichiro

    2013-08-01

    This study evaluated the safety, feasibility, and clinical utility of hyaluronic acid gel injection to separate the gastrointestinal tract from the tumor during liver radiofrequency ablation (RFA). Eleven patients with liver tumors measuring 0.9-3.5 cm (mean ± standard deviation, 2.1 ± 0.8 cm) that were adjacent to the gastrointestinal tracts received RFA after the mixture of hyaluronic acid gel and contrast material (volume, 26.4 ± 14.5 mL; range, 10-60 mL) was injected between the tumor and the gastrointestinal tract under computed tomographic-fluoroscopic guidance. Each tumor was separated from the gastrointestinal tract by 1.0-1.5 cm (distance, 1.2 ± 0.2 cm) after injection of hyaluronic acid gel, and subsequent RFA was performed without any complications in all patients. Although tumor enhancement disappeared in all patients, local tumor progression was found in a patient (9.1%, 1 of 11) during the follow-up of 5.5 ± 3.2 months (range, 0.4-9.9 months). In conclusion, hyaluronic acid gel injection is a safe and useful technique to avoid thermal injury of the adjacent gastrointestinal tract during liver RFA.

  8. Percutaneous upper thoracic radiofrequency sympathectomy in Raynaud phenomenon: a comparison of T2/T3 procedure versus T2 lesion with phenol application.

    PubMed

    Gabrhelik, Tomas; Michalek, Pavel; Adamus, Milan; Berta, Emil

    2009-01-01

    Percutaneous radiofrequency (RF) thoracic sympathectomy is an alternative method to surgical procedures for the treatment of acral ischemia in Raynaud phenomenon. The procedure is indicated if conservative therapy fails to provide sufficient relief. The aim of this study was to compare classic T2 and T3 RF thermolesioning with a less invasive procedure at the level of T2 only. Fifty adult patients, American Society of Anesthesiologists (ASA) classification I to III, were randomly assigned to 1 of 2 groups. T2 and T3 thoracic RF thermolesion was performed in 1 group, whereas T2 thermolesion with local application of 0.5 mL of 6% phenol was delivered in the second group. Changes in cold perception, pain, and quality of life were assessed using a questionnaire. Blood circulation in the upper extremity was evaluated using infrared thermography. Patients were observed for a period of 3 months. A significant decrease in pain according to visual analog scale (P < 0.001), increase in peripheral temperature in the upper extremities (P < 0.001), and improvement in quality of life were observed in both groups of patients after the procedure. Susceptibility to cold-provoked vasospasm was not significantly affected in either group. There was no significant difference between the 2 groups in any parameter apart from the duration of the procedure. Thoracic RF upper sympathectomy is an effective method in the treatment of resistant forms of Raynaud phenomenon. A single-shot procedure at the level of T2 may be preferable because of the shorter procedure duration of this technique.

  9. Comparative study of the effects of percutaneous ethanol injection and radiofrequency ablation in cases treated with a straight or expandable electrode.

    PubMed

    Kurokohchi, Kazutaka; Deguchi, Akihiro; Masaki, Tsutomu; Yoneyama, Hirohito; Himoto, Takashi; Miyoshi, Hisaaki; Mohammad, Hamdy Saad; Taminato, Tomihiko; Kuriyama, Shigeki

    2007-11-01

    Radiofrequency ablation (RFA) has become mainstream among non-surgical treatment modalities in clinical settings for the treatment of hepatocellular carcinoma. We have previously described the novel combination therapy of percutaneous ethanol injection and RFA (PEI-RFA) and reported that this combination therapy was more effective than RFA alone in terms of the induced volume of coagulated necrosis and the energy requirement for the treatment. RFA instruments are mainly divided into two types according to the electrode used, either the straight or expandable type electrode. Although PEI-RFA can be performed by either of the electrodes, there may be some important differences in PEI-RFA according to the type of electrode used. In the present study, the effect of using the straight or expandable electrode in PEI-RFA was evaluated by analyzing the ablation time, volume of coagulated necrosis, the energy requirement for ablation and the amount of injected ethanol into HCC. The comparative study showed that ablation time, total energy requirement and per unit volume of energy requirement for whole and marginal coagulated necrosis were significantly smaller in the group treated with the expandable electrode (E group) than those in the group treated with the straight electrode (S group). The volume of coagulated necrosis was similar between these groups. In group E, the amount of injected ethanol showed a positive correlation with the volume of coagulated necrosis and the size of the tumors. These results suggest that prior injection of ethanol works mainly by shortening the time and energy requirement for ablation in the time-lag PEI-RFA using the expandable electrode. Thus, prior injection of ethanol before RFA may make RFA treatment less invasive in the time-lag PEI-RFA using the expandable electrode as previously shown HCC cases treated with straight electrode.

  10. Percutaneous ethanol injection therapy is comparable to radiofrequency ablation in hepatocellular carcinoma smaller than 1.5 cm: A matched case-control comparative analysis.

    PubMed

    Yu, Su Jong; Yoon, Jung-Hwan; Lee, Jeong Min; Lee, Jae Young; Kim, Se Hyung; Cho, Young Youn; Yoo, Jeong-Ju; Lee, Minjong; Lee, Dong Hyeon; Cho, Yuri; Cho, Eun Ju; Lee, Jeong-Hoon; Kim, Yoon Jun; Kim, Chung Yong

    2016-08-01

    Although percutaneous ethanol injection therapy (PEIT) is best indicated for patients with small hepatocellular carcinoma (HCC), the survival advantage of PEIT needs confirmation in real-world practice. This study was approved by the institutional review board, and the informed consent was waived. The study included 535 consecutive patients with newly diagnosed early stage (Barcelona Clinic Liver Cancer [BCLC] 0 or A) HCC who underwent initially radiofrequency ablation (RFA) (n = 288) or PEIT (n = 247) from January 2005 to December 2010. The primary outcome was overall survival (OS) and the secondary outcome was time to progression (TTP). The longest diameters of tumors of the groups differed significantly and larger for RFA group than PEIT group (P < 0.001; 1.94 ± 0.65 cm vs 1.60 ± 0.50 cm, respectively). The 5-year OS rates were 72.2% in the RFA group and 67.4% in the PEIT group (P = 0.608). Even after propensity score matching, OS rates between the 2 groups were similar (5-year OS: 72.8% with RFA [n = 175] and 68.0% with PEIT [n = 175]) (P = 0.709). Moreover, in patients with the longest diameter of tumors (≤1.5 cm), multivariate Cox regression analysis showed that the treatment modality was not a significant prognosticator for OS (hazard ratio [HR], 1.690; 95% confidence interval [CI], 0.828-3.449; P = 0.149) and time to progression (HR, 1.160; 95% CI, 0.773-1.740; P = 0.474). PEIT and RFA show equal effectiveness in treating HCCs <1.5 cm in terms of OS and time to progression.

  11. [Treatment of small renal masses with laparoscopic radiofrequency ablation].

    PubMed

    Estébanez, Javier; Gutiérrez, Miguel Angel; Linazasoro, Ione; Belloso, Ion; Cano, Carlos; Sanz, Juan Pablo

    2013-01-01

    To perform a bibliographic review of the laparoscopic approach for radiofrequency ablation of small renal masses. For this review we used the Medline database. We reviewed the clinical guidelines of the American Urological Association, the European Association of Urology and other institutions. Radiofrequency ablation is a minimally invasive treatment in which a needle is introduced in the tumor once it is identified, and it produces an increase of temperature high enough to destroy tumor cells. This technique may be used by percutaneous approach, or during a laparoscopic approach. The choice of one technique or another depends on tumor site, closeness to the bowels or other organs and patient conditions. It would be indicated in patients with small tumors or important comorbidity who are not candidates for surgery. There are not randomized studies comparing these ablation techniques with the surgical techniques. There is no randomized study comparing the efficacy of percutaneous and laparoscopic techniques either but a metanalysis comparing them has been performed. The treatment of small renal masses keeps being surgical excision. Radiofrequency ablation represents an alternative for carefully selected patients due to its low morbidity and few complications. There are not long term efficacy studies to date. Laparoscopic radiofrequency ablation would be indicated in cases in which the percutaneous approach is complicated due to tumor site.

  12. Visualization tool for improved accuracy in needle placement during percutaneous radio-frequency ablation of liver tumors

    NASA Astrophysics Data System (ADS)

    Stüdeli, Thomas; Kalkofen, Denis; Risholm, Petter; Ali, Wajid; Freudenthal, Adinda; Samset, Eigil

    2008-03-01

    The European research network "Augmented reality in Surgery" (ARIS*ER) developed a system that supports percutaneous radio frequency ablation of liver tumors. The system provides interventionists, during placement and insertion of the RFA needle, with information from pre-operative CT images and real-time tracking data. A visualization tool has been designed that aims to support (1) exploration of the abdomen, (2) planning of needle trajectory and (3) insertion of the needle in the most efficient way. This work describes a first evaluation of the system, where user performances and feedback of two visualization concepts of the tool - needle view and user view - are compared. After being introduced to the system, ten subjects performed three needle placements with both concepts. Task fulfillment rate, time for completion of task, special incidences, accuracy of needle placement recorded and analyzed. The results show ambiguous results with beneficial and less favorable effects on user performance and workload of both concepts. Effects depend on characteristics of intra-operative tasks as well as on task complexities depending on tumor location. The results give valuable input for the next design steps.

  13. Survival comparison between surgical resection and percutaneous radiofrequency ablation for patients in Barcelona Clinic Liver Cancer early stage hepatocellular carcinoma.

    PubMed

    Wong, Kiong-Ming; Yeh, Ming-Lun; Chuang, Shih-Chung; Wang, Liang-Yen; Lin, Zu-Yau; Chen, Shinn-Cherng; Tsai, Jung-Fa; Wang, Shen-Nien; Kuo, Kung-Kai; Dai, Chia-Yen; Yu, Ming-Lung; Lee, King-The; Chuang, Wan-Long

    2013-07-01

    To compare the survival outcome between surgical resection (SR) and radiofrequency ablation (RFA) for Barcelona Clinic Liver Cancer (BCLC) early stage hepatocellular carcinoma (HCC). The retrospective study enrolled eighty-two patients with newly diagnosed BCLC early HCC (single nodule, size ≦3 cm, and Child-Pugh class A) treated either surgically (n = 46) or with RFA (n = 36) from year 2004 to 2009. The patients' survival outcomes were compared. There were no significant differences in overall survival (OS) rates between SR and RFA (p = 0.204). The 3- and 5-year disease-free survival (DFS) rates were 65.8 % and 53.7 % respectively, in the SR group, which were significantly higher than those in the RFA group (34.8 % and 14.9 % respectively) (p = 0.009 and p = 0.001). In subgroup analysis, the DFS was similar between RFA and SR in patients with presentation of lower platelet count (≦100,000/mL) and smaller tumor size (tumor size ≦1 cm). Multivariate analysis showed SR as a procedure type was a significant predictive factor for DFS [HR = 2.26 (CI 1.462-5.227), p = 0.002]. SR yielded similar OS but better DFS when compared to RFA for patients with BCLC early HCC (single nodule, ≦3 cm and Child-Pugh class A). In subgroup patients with lower platelet count (≦100,000/mL) and smaller tumor size (tumor size ≦1 cm), DFS was similar between both treatments.

  14. Comparison of percutaneous radiofrequency ablation and CyberKnife® for initial solitary hepatocellular carcinoma: A pilot study

    PubMed Central

    Shiozawa, Kazue; Watanabe, Manabu; Ikehara, Takashi; Matsukiyo, Yasushi; Kogame, Michio; Kishimoto, Yui; Okubo, Yusuke; Makino, Hiroyuki; Tsukamoto, Nobuhiro; Igarashi, Yoshinori; Sumino, Yasukiyo

    2015-01-01

    AIM: To compare therapeutic outcomes and adverse events in initial solitary hepatocellular carcinoma (HCC) treated with radiofrequency ablation (RFA) and CyberKnife®. METHODS: Seventy three consecutive patients with initial solitary HCC treated with RFA (38 patients; RFA group) and CyberKnife® (35 patients; CK group) were enrolled in this study. Background factors were compared between the two groups. Local and intrahepatic distant recurrence control, and cumulative survival rates were compared between the two groups. These were determined using the Kaplan-Meier method, and the significance of differences was analyzed by log-rank test. The presence of more grade 3 on CTCAE ver. 4.0 early and late adverse events was investigated. RESULTS: In background factors, age was significantly higher (P = 0.005) and the tumor diameter was significantly larger (P = 0.001) in the CK group. The 1-year local recurrence control rates were 97.4% and 97.1% in the RFA and CK groups, respectively (P = 0.71); the 1-year intrahepatic distant recurrence control rates were 85.6% and 86.1%, respectively (P = 0.91); and the 1-year cumulative survival rates were 100% and 95.2%, respectively (P = 0.075), showing no significant difference in any rate between the two groups. There were no late adverse event in the RFA group, but 11.4% in the CK group had late adverse events. In the CK group, the Child-Pugh score at 12 mo after treatment was significantly higher than that in the RFA group (P = 0.003) and significantly higher than the score before treatment (P = 0.034). CONCLUSION: The occurrence of adverse events is a concern, but CyberKnife® treatment is likely to become an important option for local treatment of early HCC. PMID:26730160

  15. Dynamic frame selection for in vivo ultrasound temperature estimation during radiofrequency ablation

    PubMed Central

    Daniels, Matthew J; Varghese, Tomy

    2010-01-01

    Minimally invasive therapies such as radiofrequency ablation have been developed to treat cancers of the liver, prostate and kidney without invasive surgery. Prior work has demonstrated that ultrasound echo shifts due to temperature changes can be utilized to track the temperature distribution in real time. In this paper, a motion compensation algorithm is evaluated to reduce the impact of cardiac and respiratory motion on ultrasound-based temperature tracking methods. The algorithm dynamically selects the next suitable frame given a start frame (selected during the exhale or expiration phase where extraneous motion is reduced), enabling optimization of the computational time in addition to reducing displacement noise artifacts incurred with the estimation of smaller frame-to-frame displacements at the full frame rate. A region of interest that does not undergo ablation is selected in the first frame and the algorithm searches through subsequent frames to find a similarly located region of interest in subsequent frames, with a high value of the mean normalized cross-correlation coefficient value. In conjunction with dynamic frame selection, two different two-dimensional displacement estimation algorithms namely a block matching and multilevel cross-correlation are compared. The multi-level cross-correlation method incorporates tracking of the lateral tissue expansion in addition to the axial deformation to improve the estimation performance. Our results demonstrate the ability of the proposed motion compensation using dynamic frame selection in conjunction with the two-dimensional multilevel cross-correlation to track the temperature distribution. PMID:20671353

  16. Dynamic frame selection for in vivo ultrasound temperature estimation during radiofrequency ablation

    NASA Astrophysics Data System (ADS)

    Daniels, Matthew J.; Varghese, Tomy

    2010-08-01

    Minimally invasive therapies such as radiofrequency ablation have been developed to treat cancers of the liver, prostate and kidney without invasive surgery. Prior work has demonstrated that ultrasound echo shifts due to temperature changes can be utilized to track the temperature distribution in real time. In this paper, a motion compensation algorithm is evaluated to reduce the impact of cardiac and respiratory motion on ultrasound-based temperature tracking methods. The algorithm dynamically selects the next suitable frame given a start frame (selected during the exhale or expiration phase where extraneous motion is reduced), enabling optimization of the computational time in addition to reducing displacement noise artifacts incurred with the estimation of smaller frame-to-frame displacements at the full frame rate. A region of interest that does not undergo ablation is selected in the first frame and the algorithm searches through subsequent frames to find a similarly located region of interest in subsequent frames, with a high value of the mean normalized cross-correlation coefficient value. In conjunction with dynamic frame selection, two different two-dimensional displacement estimation algorithms namely a block matching and multilevel cross-correlation are compared. The multi-level cross-correlation method incorporates tracking of the lateral tissue expansion in addition to the axial deformation to improve the estimation performance. Our results demonstrate the ability of the proposed motion compensation using dynamic frame selection in conjunction with the two-dimensional multilevel cross-correlation to track the temperature distribution.

  17. Myocardial gene transfer by selective pressure-regulated retroinfusion of coronary veins: comparison with surgical and percutaneous intramyocardial gene delivery.

    PubMed

    Raake, Philip; von Degenfeld, Georges; Hinkel, Rabea; Vachenauer, Robert; Sandner, Torleif; Beller, Sabrina; Andrees, Martin; Kupatt, Christian; Schuler, Gerhard; Boekstegers, Peter

    2004-09-01

    We sought to study adenoviral gene delivery using percutaneous selective pressure-regulated retroinfusion and to compare it directly with surgical and percutaneous intramyocardial delivery (PIMD) for the first time. Intramyocardial delivery (IMD) has been recommended to be the preferred gene delivery strategy so far. However, surgical and percutaneous intramyocardial injection lead to incomplete retention of the injected viral vectors and to limited spatial myocardial distribution. Percutaneous selective pressure-regulated retroinfusion of the coronary veins was developed recently to provide an effective and more homogenous regional myocardial gene transfer. In 15 pigs, adenoviral vectors (Ad2-CMV beta-galactosidase [beta-gal] 5 x 10(9) pfu) were applied via surgical IMD (n = 5), PIMD (n = 5), and selective pressure-regulated retroinfusion (n = 5). Seven days after gene transfer, myocardial beta-gal expression was measured by ELISA. Selective retroinfusion into the anterior cardiac vein substantially increased reporter gene expression (1,039 +/- 79 pg beta-gal/mg protein) in the targeted left anterior descending coronary artery territory when compared with surgical (448 +/- 127, p < 0.05) and PIMD (842 +/- 145, p < 0.05). Both IMD approaches showed an inhomogenous beta-gal expression, particularly along the injection sites, while retroinfusion resulted in a more homogenous transmural gene expression. Percutaneous selective pressure-regulated retroinfusion compares favorably with surgical and percutaneous intramyocardial injection techniques by providing a more homogenous and even more efficient adenoviral gene delivery.

  18. Radiofrequency thermal ablation of osteoid osteomas of the proximal femur. Usefulness of ultrasound guidance in selected cases.

    PubMed

    Ramos-Pascua, L R; Martínez-Valderrábano, V; Santos-Sánchez, J A; Tijerín Bueno, M; Sánchez-Herráez, S

    2015-01-01

    To review symptoms and imaging findings of proximal femoral osteoid osteomas (OO); to analyse the results of a thermal ablation technique for radiofrequency of the nidus in this location; and to describe usefulness of ultrasound guidance in selected cases. Descriptive and retrospective study consisting of 8 patients with OO in the proximal epiphysis of the femur, which were treated by thermal ablation of the nidus with radiofrequency waves from 1998 to 2004. The mean pain period until the performance of the thermal ablation was 11.5 months (range 5-18 months). There were no complications, and all patients stated that the pain was gone by the day following the procedure, with some discomfort during the first week, except for one where it lasted more than one month due to technique difficulties. At present, with a mean follow up of 6 years and 2 months (range 6-190 months), all patients remain asymptomatic and live a rigorous normal life. Thermal ablation with CT-guided radiofrequency waves is a safe, effective and efficient procedure. Normal appearance of a proximal femoral OO does not differ significantly from other location osteomas and its diagnosis is easier with previous knowledge. Thermal ablation of the nidus with radiofrequency waves, that may be performed using ultrasound guidance, appears to be the elective treatment of choice due to its efficiency and minimum morbidity. Copyright © 2014 SECOT. Published by Elsevier Espana. All rights reserved.

  19. Selective Non-contact Field Radiofrequency Extended Treatment Protocol: Evaluation of Safety and Efficacy.

    PubMed

    Moradi, Amir; Palm, Melanie

    2015-09-01

    Currently there are many non-invasive radiofrequency (RF) devices on the market that are utilized in the field of aesthetic medicine. At this time, there is only one FDA cleared device on the market that emits RF energy using a non-contact delivery system for circumferential reduction by means of adipocyte disruption. Innovation of treatment protocols is an integral part of aesthetic device development. However, when protocol modifications are made it is important to look at the safety as well as the potential for improved efficacy before initiating change. The purpose of this study was to evaluate the safety and efficacy of a newly designed extended treatment protocol using an operator independent selective non-contact RF device for the improvement in the contour and circumferential reduction of the abdomen and flanks (love handles). Twenty-five subjects enrolled in the IRB approved multi-center study to receive four weekly 45-minute RF treatments to the abdomen and love handles. Standardized digital photographs and circumference measurements were taken at baseline and at the 1- and 3-month follow-up visits. Biometric measurements including weight, hydration and body fat were obtained at baseline and each study visit. A subset of 4 subjects were randomly selected to undergo baseline serum lipid and liver-related blood tests with follow-up labs taken: 1 day post-treatment 1, 1 day post-treatment 4, and at the 1- and 3-month follow-up visits. Twenty-four subjects (22 female, 2 male), average age of 47.9 years (30-69 years), completed the study. The data of the twenty-four subjects revealed a statistically significant change in circumference P<.001 with an average decrease in circumference of 4.22cm at the 3-month follow-up visit. Lab values for the subset of 4 subjects remained relatively unchanged with only minor fluctuations noted in the serum lipid values in two of the subjects. Three independent evaluators viewed pre-treatment and 3-month post treatment

  20. Percutaneous Selective Vertebroplasty: State of the Art Management in Well-Confined Metastatic Vertebral Lesions

    PubMed Central

    2016-01-01

    Study Design Prospective cohort study. Purpose To evaluate the clinical and radiological results of percutaneous selective vertebroplasty (PSV) as first-line treatment options in the setting of well-confined spinal metastases. Overview of Literature Recent technological advances combined with innovative interventional techniques enable an alternative less invasive treatment option for many patients with malignant vertebral body infiltration. Percutaneous vertebral augmentation procedures offer less invasive but effective pain relief to many patients with symptomatic spinal metastatic disease. Methods Eleven patients with 21 well-confined metastatic vertebral lesions that had been treated with PSV were included. Pain was evaluated one week, one month, 3 months and 6 months post-procedure using a 10-point visual analogue scale (VAS). A statistical analysis including repeated measures analysis of variance test was used to collectively indicate the presence of any significant differences between different time sequences. Medication usage and range of mobility were also evaluated. Results The 11 patients had an average age of 42 years and 54.5% were male. Highly significant improvements in VAS scores at rest and with activity (p<0.001) were evident. There was a significant decrease in rate of medication consumption post-procedure (p<0.05). Conclusions PSV can be used successfully as the first-line treatment for well-confined metastatic vertebral lesions. It is also an effective method to decrease pain, increase mobility, and decrease narcotic administration in such patients. PMID:27790314

  1. Percutaneous Ultrasound-Guided TOPAZ Radiofrequency Coblation: A Novel Coaxial Technique for the Treatment of Recalcitrant Plantar Fasciitis-Our Experience.

    PubMed

    Shah, Amit; Best, Alistair J; Rennie, Winston J

    2016-06-01

    Various therapeutic options are available for treatment of recalcitrant plantar fasciitis. Studies using TOPAZ coblation (ArthroCare, Sunnyvale, CA) have had good early results. The current coblation technique involves a surgical incision or breach of the highly specialized plantar fat pad, which can be associated with risks. We describe a novel technique of ultrasound-guided percutaneous coblation with a lateral heel approach. Advantages include precise targeting of the plantar fascia by direct dynamic visualization of the coblation tip, a true percutaneous approach with a needle skin puncture (<5 mm), and preservation of the plantar fat pad by using a lateral heel approach.

  2. Renal zoomed EPI-DWI with spatially-selective radiofrequency excitation pulses in two dimensions.

    PubMed

    He, Yong-Lan; Hausmann, Daniel; Morelli, John N; Attenberger, Ulrike I; Schoenberg, Stefan O; Riffel, Philipp

    2016-10-01

    To evaluate the feasibility and clinical robustness of zoomed diffusion-weighted echo planar imaging (z-EPI) relative to conventional single-shot EPI (c-EPI) for DWI of the kidneys. This retrospective study was approved by the institutional research ethics board. 66 patients (median age 58.5 years±13.4, range 23-83 years, 45 men, 21 women) undergoing 3T (Magnetom Skyra(®), Siemens Healthcare, Erlangen, Germany) using a dynamic parallel transmit array (TimTX TrueShape, Siemens Healthcare, Erlangen, Germany) for renal MRI were included in this study. Both c-EPI and z-EPI images were obtained. For z-EPI, a two-dimensional spatially-selective radiofrequency (RF) pulse was applied for echo planar imaging with the FOV reduced by a factor of 3. Two radiologists, blinded to clinical data and scan parameters evaluated the images with respect to their diagnostic confidence, overall preference, overall image quality, delineation of the kidney, spatial distortion, and image blur. Sequences were compared using a paired Wilcoxon test. ADC values for the upper pole, mid-zone, lower pole of the normal kidneys were compared between sequences as well as ADC values for renal lesions, using a paired t-test. With z-EPI, the kidney was significantly better delineated with sharper boundaries, less image blur and distortion, and overall better image quality relative to c-EPI (all p<0.001). The z-EPI technique led to greater diagnostic confidence than c-EPI (p=0.020). z-EPI was preferred to c-EPI in 60 cases (90.9%, 60/66). No statistically significant differences in the ADC values of renal parenchyma or of renal lesions were observed between the two sequences (all p>0.05). Image quality, distortion, and susceptibility artifacts might be improved by using z-EPI rather than c-EPI for DWI of the kidney. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. Do Liposomal Apoptotic Enhancers Increase Tumor Coagulation and End-Point Survival in Percutaneous Radiofrequency Ablation of Tumors in a Rat Tumor Model? 1

    PubMed Central

    Yang, Wei; Elian, Mostafa; Hady, El-Shymma A.; Levchenko, Tatyana S.; Sawant, Rupa R.; Signoretti, Sabina; Collins, Michael; Torchilin, Vladimir P.; Goldberg, S. Nahum

    2010-01-01

    Purpose: To characterize effects of combining radiofrequency (RF) ablation with proapoptotic intravenous liposome-encapsulated paclitaxel and doxorubicin on tumor destruction, apoptosis and heat-shock protein (HSP) production, intratumoral drug accumulation, and end-point survival. Materials and Methods: R3230 mammary adenocarcinomas (n = 177) were implanted in 174 rats in this animal care committee–approved study. Tumors received (a) no treatment, (b) RF ablation, (c) paclitaxel, (d) RF ablation followed by paclitaxel (RF ablation–paclitaxel), (e) paclitaxel before RF ablation (paclitaxel–RF ablation), (f) RF ablation followed by doxorubicin (RF ablation–doxorubicin), (g) paclitaxel followed by doxorubicin without RF ablation (paclitaxel-doxorubicin), or (h) paclitaxel before RF ablation, followed by doxorubicin (paclitaxel–RF ablation–doxorubicin). Tumor coagulation area and diameter were compared at 24–96 hours after treatment. Intratumoral paclitaxel uptake with and without RF ablation were compared. Immunohistochemical staining revealed cleaved caspase-3 and 70-kDa HSP (HSP70) expression. Tumors were randomized into eight treatment arms for Kaplan-Meier analysis of defined survival end-point (3.0-cm diameter). Results: Paclitaxel–RF ablation increased tumor coagulation over RF ablation or paclitaxel (mean, 14.0 mm ± 0.9 [standard deviation], 6.7 mm ± 0.6, 2.5 mm ± 0.6, respectively; P < .001). Paclitaxel–RF ablation–doxorubicin had similar tumor coagulation (P < .05), compared with paclitaxel–RF ablation, at 24 and 96 hours. Mean intratumoral paclitaxel accumulation for paclitaxel–RF ablation (6.76 μg/g ± 0.35) and RF ablation–paclitaxel (9.28 μg/g ± 0.87) increased over that for paclitaxel (0.63 μg/g ± 0.25, P < .001). Paclitaxel substantially increased apoptosis and decreased HSP70 expression at coagulation margin. Mean end-point survival for paclitaxel–RF ablation–doxorubicin (56.8 days ± 25.3) was greater, compared

  4. Percutaneous Selective Embolectomy using a Fogarty Thru-Lumen Catheter for Pancreas Graft Thrombosis: A Case Report

    SciTech Connect

    Izaki, Kenta Yamaguchi, Masato; Matsumoto, Ippei; Shinzeki, Makoto; Ku, Yonson; Sugimura, Kazuro; Sugimoto, Koji

    2011-06-15

    A 57-year-old woman with a history of diabetes mellitus underwent simultaneous pancreas-kidney transplantation. The pancreaticoduodenal graft was implanted in the right iliac fossa. The donor's portal vein was anastomosed to the recipient's inferior vena cava (IVC). Seven days after the surgery, a thrombus was detected in the graft veins. Percutaneous thrombolysis was immediately performed; however, venous congestion was still present. We therefore attempted selective embolectomy using a Fogarty Thru-Lumen Catheter. Thrombi were directed from the graft veins toward the IVC and captured in the IVC filter with complete elimination of the thrombus without any major complications. We present our technique for the successful treatment of pancreas graft thrombosis within a short time period by percutaneous selective embolectomy using a Fogarty Thru-Lumen Catheter.

  5. Needle track seeding following percutaneous procedures for hepatocellular carcinoma

    PubMed Central

    Cabibbo, Giuseppe; Craxì, Antonio

    2009-01-01

    Neoplastic seeding may arise after diagnostic or therapeutic percutaneous procedures for hepatocellular carcinoma. The true incidence of seeding with hepatocellular carcinoma is difficult to assess precisely, but a significant risk of seeding exists and is greater when performing diagnostic biopsy as compared to therapeutic percutaneous procedures [radiofrequency ablation, radiofrequency ablation (RFA); percutaneous ethanol injection, Percutaneous ethanol injection (PEI)]. Whenever liver transplantation is feasible, diagnostic needle biopsies should be avoided, but RFA and PEI are often needed as “bridge” treatments. The role of adjuvant treatments in reducing the incidence of seeding following RFA or PEI requires further evaluation. PMID:21160966

  6. Risk‐Treatment Paradox in the Selection of Transradial Access for Percutaneous Coronary Intervention

    PubMed Central

    Wimmer, Neil J.; Resnic, Frederic S.; Mauri, Laura; Matheny, Michael E.; Piemonte, Thomas C.; Pomerantsev, Eugene; Ho, Kalon K. L.; Robbins, Susan L.; Waldman, Howard M.; Yeh, Robert W.

    2013-01-01

    Background Access site complications contribute to morbidity and mortality during percutaneous coronary intervention (PCI). Transradial arterial access significantly lowers the risk of access site complications compared to transfemoral arteriotomy. We sought to develop a prediction model for access site complications in patients undergoing PCI with femoral arteriotomy, and assess whether transradial access was selectively used in patients at high risk for complications. Methods and Results We analyzed 17 509 patients who underwent PCI without circulatory support from 2008 to 2011 at 5 institutions. Transradial arterial access was used in 17.8% of patients. In those who underwent transfemoral access, 177 (1.2%) patients had access site complications. Using preprocedural clinical and demographic data, a prediction model for femoral arteriotomy complications was generated. The variables retained in the model included: elevated age (P<0.001), female gender (P<0.001), elevated troponin (P<0.001), decreased renal function or dialysis (P=0.002), emergent PCI (P=0.01), prior PCI (P=0.005), diabetes (P=0.008), and peripheral artery disease (P=0.003). The model showed moderate discrimination (optimism‐adjusted c‐statistic=0.72) and was internally validated via bootstrap resampling. Patients with higher predicted risk of complications via transfemoral access were less likely to receive transradial access (P<0.001). Similar results were seen in patients presenting with and without ST‐segment myocardial infarction and when adjusting for individual physician operator. Conclusions We generated and validated a model for transfemoral access site complications during PCI. Paradoxically, patients most likely to develop access site complications from transfemoral access, and therefore benefit from transradial access, were the least likely to receive transradial access. PMID:23709565

  7. The efficacy of a two needle electrode technique in percutaneous radiofrequency rhizotomy:An investigational laboratory study in an animal model.

    PubMed

    Derby, Richard; Lee, Chang-Hyung

    2006-07-01

    Radiofrequency neurotomies are used to help reduce pain caused by structures innervated by the medial branch of the dorsal spinal nerve. The duration of effect may vary proportionally to the length of nerve coagulated. Techniques used to maximize the length of nerve within the radius of maximal heat include making multiple lesions, using larger needles, positioning the exposed needle parallel to the target nerve, and attempting more precise placement using 50 hertz test stimulation. A variation of the technique uses two needles that are simultaneously placed to lie parallel to one another and parallel to the probable area the target nerve is known to traverse. Heating both needles at the same time would be a faster method that theoretically might also include more tissue within the heating radius of the needle lengths. The purpose of this study was to confirm that two parallel radiofrequency lesions increased the volume of tissue included within the heating radius of the exposed needle tips, to determine optimal heating parameters, and to establish how far apart the needles can be placed and still achieve temperatures between the needles that will coagulate nerves. Investigational laboratory study in an animal model. Ex-vivo porcine spinal tissue samples were prepared following a standardized protocol and two needle electrodes were connected to the Stryker rhizotomy device. A series of tissue samples were prepared with the needles placed 1, 1.5, 2, 3, 4, 5, 6, 7, 8, or 9 mm apart in respective samples. The needles were positioned parallel to the surface, and perpendicular to the tissue. In one series of samples, two needle electrodes were heated sequentially for each needle placement. Temperature parameters ranged from 60 to 100 degrees C and the time duration ranged from 60 to 90 seconds for each electrode. After each heating, all tissue was dissected and the size of the coagulated area measured. Temperatures at the midpoint between the two needle electrodes were

  8. Development of radio-frequency identification sensors based on organic electronic sensing materials for selective detection of toxic vapors

    NASA Astrophysics Data System (ADS)

    Potyrailo, Radislav A.; Surman, Cheryl; Go, Steven; Lee, Yongjae; Sivavec, Timothy; Morris, William G.

    2009-12-01

    Selective vapor sensors are demonstrated that involve the combination of (1) organic electronic sensing materials with diverse response mechanisms to different vapors and (2) passive 13.56 MHz radio-frequency identification (RFID) sensors with multivariable signal transduction. Intrinsically conducting polymers such as poly(3,4-ethylenedioxythiophene) and polyaniline (PANI) were applied onto resonant antennas of RFID sensors. These sensing materials are attractive to facilitate the critical evaluation of our sensing concept because they exhibit only partial vapor selectivity and have well understood diverse vapor response mechanisms. The impedance spectra Ž(f) of the RFID antennas were inductively acquired followed by spectral processing of their real Zre(f) and imaginary Zim(f) parts using principal components analysis. The typical measured 1σ noise levels in frequency and impedance magnitude measurements were 60 Hz and 0.025 Ω, respectively. These low noise levels and the high sensitivity of the resonant RFID sensor structures resulted in NH3 determinations with the 3σ detection limit down to 20 ppb. This achieved detection limit was 25-50-fold better over chemoresistor sensors based on PANI films and nanowires.

  9. Percutaneous Radiofrequency Ablation of Painful Spinal Tumors Adjacent to the Spinal Cord with Real-Time Monitoring of Spinal Canal Temperature: A Prospective Study

    SciTech Connect

    Nakatsuka, Atsuhiro Yamakado, Koichiro; Takaki, Haruyuki; Uraki, Junji; Makita, Masashi; Oshima, Fumiyoshi; Takeda, Kan

    2009-01-15

    PurposeTo prospectively evaluate the feasibility, safety, and clinical utility of bone radiofrequency (RF) ablation with real-time monitoring of the spinal canal temperature for the treatment of spinal tumors adjacent to the spinal cord.Materials and MethodsOur Institutional Review Board approved this study. Patients gave informed consent. The inclusion criteria were (a) a painful spinal metastasis and (b) a distance of 1 cm or less between the metastasis and the spinal cord. The thermocouple was placed in the spinal canal under CT fluoroscopic guidance. When the spinal canal temperature reached 45{sup o}C, RF application was immediately stopped. RF ablation was considered technically successful when the procedure was performed without major complications. Clinical success was defined as a fall in the visual analogue scale score of at least 2 points.ResultsTen patients with spinal tumors measuring 3-8 cm (mean, 4.9 {+-} 1.5 cm) were enrolled. The distance between the tumor and the spinal cord was 1-6 mm (mean, 2.4 {+-} 1.6 mm). All procedures were judged technically successful (100%). The spinal canal temperature did not exceed 45{sup o}C in 9 of the 10 patients (90%). In the remaining patient, the temperature rose to 48{sup o}C, resulting in transient neural damage, although RF application was immediately stopped when the temperature reached 45{sup o}C. Clinical success was achieved within 1 week in all patients (100%).ConclusionBone RF ablation with real-time monitoring of the spinal canal temperature is feasible, safe, and clinically useful for the treatment of painful spinal metastases adjacent to the spinal cord.

  10. Percutaneous radiofrequency ablation of painful spinal tumors adjacent to the spinal cord with real-time monitoring of spinal canal temperature: a prospective study.

    PubMed

    Nakatsuka, Atsuhiro; Yamakado, Koichiro; Takaki, Haruyuki; Uraki, Junji; Makita, Masashi; Oshima, Fumiyoshi; Takeda, Kan

    2009-01-01

    To prospectively evaluate the feasibility, safety, and clinical utility of bone radiofrequency (RF) ablation with real-time monitoring of the spinal canal temperature for the treatment of spinal tumors adjacent to the spinal cord. Our Institutional Review Board approved this study. Patients gave informed consent. The inclusion criteria were (a) a painful spinal metastasis and (b) a distance of 1 cm or less between the metastasis and the spinal cord. The thermocouple was placed in the spinal canal under CT fluoroscopic guidance. When the spinal canal temperature reached 45 degrees C, RF application was immediately stopped. RF ablation was considered technically successful when the procedure was performed without major complications. Clinical success was defined as a fall in the visual analogue scale score of at least 2 points. Ten patients with spinal tumors measuring 3-8 cm (mean, 4.9 +/- 1.5 cm) were enrolled. The distance between the tumor and the spinal cord was 1-6 mm (mean, 2.4 +/- 1.6 mm). All procedures were judged technically successful (100%). The spinal canal temperature did not exceed 45 degrees C in 9 of the 10 patients (90%). In the remaining patient, the temperature rose to 48 degrees C, resulting in transient neural damage, although RF application was immediately stopped when the temperature reached 45 degrees C. Clinical success was achieved within 1 week in all patients (100%). Bone RF ablation with real-time monitoring of the spinal canal temperature is feasible, safe, and clinically useful for the treatment of painful spinal metastases adjacent to the spinal cord.

  11. Determinants of Local Progression After Computed Tomography-Guided Percutaneous Radiofrequency Ablation for Unresectable Lung Tumors: 9-Year Experience in a Single Institution

    SciTech Connect

    Okuma, Tomohisa Matsuoka, Toshiyuki; Yamamoto, Akira; Oyama, Yoshimasa; Hamamoto, Shinichi; Toyoshima, Masami; Nakamura, Kenji; Miki, Yukio

    2010-08-15

    The purpose of this study was to retrospectively determine the local control rate and contributing factors to local progression after computed tomography (CT)-guided radiofrequency ablation (RFA) for unresectable lung tumor. This study included 138 lung tumors in 72 patients (56 men and 16 women; age 70.0 {+-} 11.6 years (range 31-94); mean tumor size 2.1 {+-} 1.2 cm [range 0.2-9]) who underwent lung RFA between June 2000 and May 2009. Mean follow-up periods for patients and tumors were 14 and 12 months, respectively. The local progression-free rate and survival rate were calculated to determine the contributing factors to local progression. During follow-up, 44 of 138 (32%) lung tumors showed local progression. The 1-, 2-, 3-, and 5-year overall local control rates were 61, 57, 57, and 38%, respectively. The risk factors for local progression were age ({>=}70 years), tumor size ({>=}2 cm), sex (male), and no achievement of roll-off during RFA (P < 0.05). Multivariate analysis identified tumor size {>=}2 cm as the only independent factor for local progression (P = 0.003). For tumors <2 cm, 17 of 68 (25%) showed local progression, and the 1-, 2-, and 3-year overall local control rates were 77, 73, and 73%, respectively. Multivariate analysis identified that age {>=}70 years was an independent determinant of local progression for tumors <2 cm in diameter (P = 0.011). The present study showed that 32% of lung tumors developed local progression after CT-guided RFA. The significant risk factor for local progression after RFA for lung tumors was tumor size {>=}2 cm.

  12. Radiofrequency Neurotomy

    MedlinePlus

    ... 24 hours after your procedure. Avoid using a heating pad on the injection sites. Avoid baths for ... Smith AD, et al. Cervical radiofrequency neurotomy reduces central hyperexcitability and improves neck movement in individuals with ...

  13. Spectrally selective three-dimensional dynamic balanced steady-state free precession for hyperpolarized C-13 metabolic imaging with spectrally selective radiofrequency pulses.

    PubMed

    Shang, Hong; Sukumar, Subramaniam; von Morze, Cornelius; Bok, Robert A; Marco-Rius, Irene; Kerr, Adam; Reed, Galen D; Milshteyn, Eugene; Ohliger, Michael A; Kurhanewicz, John; Larson, Peder E Z; Pauly, John M; Vigneron, Daniel B

    2017-09-01

    Balanced steady-state free precession (bSSFP) sequences can provide superior signal-to-noise ratio efficiency for hyperpolarized (HP) carbon-13 ((13) C) magnetic resonance imaging by efficiently utilizing the nonrecoverable magnetization, but managing their spectral response is challenging in the context of metabolic imaging. A new spectrally selective bSSFP sequence was developed for fast imaging of multiple HP (13) C metabolites with high spatiotemporal resolution. This novel approach for bSSFP spectral selectivity incorporates optimized short-duration spectrally selective radiofrequency pulses within a bSSFP pulse train and a carefully chosen repetition time to avoid banding artifacts. The sequence enabled subsecond 3D dynamic spectrally selective imaging of (13) C metabolites of copolarized [1-(13) C]pyruvate and [(13) C]urea at 2-mm isotropic resolution, with excellent spectral selectivity (∼100:1). The sequence was successfully tested in phantom studies and in vivo studies with normal mice. This sequence is expected to benefit applications requiring dynamic volumetric imaging of metabolically active (13) C compounds at high spatiotemporal resolution, including preclinical studies at high field and, potentially, clinical studies. Magn Reson Med 78:963-975, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  14. Comparison of toxicity of selected mustard agents by percutaneous and subcutaneous routes.

    PubMed

    Sharma, Manoj; Vijayaraghavan, R; Ganesan, K

    2008-12-01

    Comparative toxicity of nitrogen mustards (HN-1, HN-2 and HN-3) and sulphur mustard was carried out in mice. Based on LD50, the toxicity pattern was HN-2 < HN-1 < HN-3 < sulphur mustard by percutaneous route whereas, by subcutaneous route the toxicity pattern was sulphur mustard < HN-3 < HN-2 < HN-1. Single dose of 1 LD50 of nitrogen mustards and sulphur mustard was administered percutaneously and various oxidative stress parameters were also evaluated. The weight loss was more in HN-2 on day 3 and in sulphur mustard on day 7. There was a drastic fall of WBC count on day 3 in all groups with a recovery in nitrogen mustard groups on day 7. The RBC count and haemoglobin content showed a significant increase on day 7 in sulphur mustard group. The plasma enzymes (ALT, AST and ALP) showed an increase in all groups on day 3 and day 7. The hepatic GSH and GSSG contents were reduced and MDA content increased in all groups, with a further change in sulphur mustard on 7 day. Extensive DNA fragmentation was observed in all the nitrogen mustard groups compared to sulphur mustard group, on day 3. However, on the day 7 the DNA fragmentation was same in all groups. This study showed that the nitrogen mustards and sulphur mustard were extremely toxic by percutaneous route and caused oxidative stress. Sulphur mustard was more toxic by the percutaneous route and the effects were delayed and progressive.

  15. Percutaneous pulsed radiofrequency treatment of the cervical dorsal root ganglion in the treatment of chronic cervical pain syndromes: a clinical audit.

    PubMed

    Van Zundert, J; Lamé, I E; de Louw, A; Jansen, J; Kessels, F; Patijn, J; van Kleef, M

    2003-01-01

    Cervicogenic headache and cervicobrachialgia are frequent diagnoses of chronic cervical pain. After failure of conservative treatment, an interventional approach may be indicated in the absence of any indication for causal surgical treatment. The pulsed radiofrequency (PRF) technique exposes the nerve to a high-frequency electric field while the temperature of the electrode tip does not exceed 42°C. This method is thought to be nondestructive and almost free of neurologic side effects and complications. Our extended pilot study was performed to confirm the perceived efficacy of PRF for short- and long-term relief of chronic cervical pain. We carried out a clinical audit of the first 18 patients treated with PRF at the cervical dorsal root ganglion. An independent evaluator reviewed the medical records. Patients with good clinical results at 8 weeks were evaluated for long-term effect (> 6 months), based on a 7-point Likert scale. Thirteen patients (72%) showed short-term clinical success (≥ 50% pain relief). Mean follow-up was 19.4 months (SD 8.9 months), maximum 2.5 years. The duration of satisfactory pain relief (6 or 7 on the Likert scale) varied between 2 and over 30 months, with a mean duration of 9.2 months (SD 11.2 months). Kaplan-Meier analysis illustrated that 50% of patients experienced success 3 months after treatment. We could not identify predictive variables for clinical outcome. None of the patients reported post-treatment neuritis or other adverse events. To our knowledge, this is the first documented series of chronic cervical pain syndromes treated with PRF. Satisfactory pain relief of at least 50% was achieved in 13 of 18 (72%) patients at 8 weeks. More than one year after treatment, six patients (33%) continue to rate treatment outcome as good or very good. No side effects were reported. j.

  16. Simultaneous functional MRI acquisition of distributed brain regions with high temporal resolution using a 2D-selective radiofrequency excitation.

    PubMed

    Finsterbusch, Jürgen

    2015-02-01

    To perform simultaneous functional MRI of multiple, distributed brain regions at high temporal resolution using a 2D-selective radiofrequency (2DRF) excitation. A tailored 2DRF excitation is used to excite several, small regions-of-interest distributed in the brain. They are acquired in a single projection image with an appropriately chosen orientation such that the different regions-of-interest can be discriminated by their position in the projection plane. Thus, they are excited and acquired simultaneously with a temporal resolution comparable to that of a single-slice measurement. The feasibility of this approach for functional neuroimaging (in-plane resolution 2 × 2 mm(2) ) at high temporal resolution (80 ms) is demonstrated in healthy volunteers for regions-of-interest in the visual and motor system using checkerboard and finger tapping block-design paradigms. Task-related brain activation could be observed in both the visual and the motor system simultaneously with a high temporal resolution. For an onset shift of 240 ms for half of the checkerboard, a delay of the hemodynamic response in the corresponding hemisphere of the visual cortex could be detected. Limiting the excited magnetization to the desired target regions with a 2DRF excitation reduces the imaging sampling requirements which can improve the temporal resolution significantly. © 2014 Wiley Periodicals, Inc.

  17. Selective and localized radiofrequency heating of skin and fat by controlling surface distributions of the applied voltage: analytical study

    NASA Astrophysics Data System (ADS)

    Jiménez-Lozano, Joel; Vacas-Jacques, Paulino; Anderson, R. Rox; Franco, Walfre

    2012-11-01

    At low frequencies (hundreds of kHz to a few MHz), local energy absorption is proportional to the conductivity of tissue and the intensity of the internal electric field. At 1 MHz, the electric conductivity ratio between skin and fat is approximately 10; hence, skin would heat more provided the intensity of the electric field is similar in both tissues. It follows that selective and localized heat deposition is only feasible by varying electric fields locally. In this study, we vary local intensities of the internal electric field in skin, fat and muscle by altering its direction through modifying surface distributions of the applied voltage. In addition, we assess the long-term effects of these variations on tissue thermal transport. To this end, analytical solutions of the electric and bioheat equations were obtained using a regular perturbation method. For voltage distributions given by second- and eight-degree functions, the power absorption in fat is much greater than in skin by the electrode center while the opposite is true by the electrode edge. For a sinusoidal function, the absorption in fat varies laterally from greater to lower than in skin, and then this trend repeats from the center to the edge of the electrode. Consequently, zones of thermal confinement selectively develop in the fat layer. Generalizing these functions by parametrization, it is shown that radiofrequency (RF) heating of layered tissues can be selective and precisely localized by controlling the spatial decay, extent and repetition of the surface distribution of the applied voltage. The clinical relevance of our study is to provide a simple, non-invasive method to spatially control the heat deposition in layered tissues. By knowing and controlling the internal electric field, different therapeutic strategies can be developed and implemented.

  18. Clinical Efficacy of Selective Focal Ablation by Navigable Percutaneous Disc Decompression Device in Patients With Cervical Herniated Nucleus Pulposus

    PubMed Central

    2017-01-01

    Objective To evaluate the clinical efficacy and safety following percutaneous disc decompression, using navigable disc decompression device for cervical herniated nucleus pulposus (HNP). Methods Twenty subjects diagnosed with cervical HNP and refractory to conservative management were enrolled for the study. The herniated discs were decompressed under fluoroscopic guidance, using radiofrequency ablation device with navigable wand. The sagittal and axial plain magnetic resonance images of the clinically significant herniated disc, decided the space between the herniated base and outline as the target area for ablation. Clinical outcome was determined by Numeric Rating Scale (NRS), Neck Disability Index (NDI), and Bodily Pain scale of Short Form-36 (SF-36 BP), assessed after 48 weeks. After the procedure, we structurally matched the magnetic resonance imaging (MRI) and C-arm images through bony markers. The wand position was defined as being ‘correct’ if the tip was placed within the target area of both AP and lateral views; if not, the position was stated as ‘incorrect’. Results The average NRS fell from 7 to 1 at 48 weeks post procedure (p<0.05). In addition, statistically significant improvement was noted in the NDI and SF-36BP (p<0.05). The location of the wand tip resulted in 16 correct and 4 incorrect placements. Post-48 weeks, 3 of the incorrect tip cases and 1 correct tip case showed unsuccessful outcomes. Conclusion The study demonstrated the promising results and safety of the procedure. Thus, focal plasma ablation of cervical HNP with navigable wand can be another effective treatment option. PMID:28289639

  19. [Radiofrequency for the treatment of liver tumors].

    PubMed

    Elias, D; De Baere, T

    2001-04-01

    Radiofrequency is performed with thin electrodes that are placed in the center of a tumor under ultrasonographic guidance. Radiofrequency waves induce ionic agitation which destroys neighboring tissues by heat. The most recent equipment can produce necrosis of 4-cm diameter areas. Efficacy is enhanced by blocking intrahepatic blood flow which naturally refreshes the liver parenchyma. The technique has the advantage of minimal invasion and of sparing liver parenchymal tissue. radiofrequency can be performed percutaneously or by laparoscopi or laparotomy. results in most reported series have been good with low morbidity. rapid improvment of material and of new associated procedures (vascular clamping, cooling infusion of the bile ducts, transplaeurodiaphragmatic approach, combination with other new approaches in liver surgery) are continuously modifying performance levels and potential indications curently under validation. radiofrequency, like other tools for local tumor destruction, will greatly change our therapeutic strategies in the neat future.

  20. Radiofrequency: Thermage.

    PubMed

    Polder, Kristel D; Bruce, Suzanne

    2011-05-01

    Nonablative procedures for facial rejuvenation have become increasingly popular. One such method to improve laxity and diminish rhytids is monopolar capacitively coupled radiofrequency (MRF). The authors discuss clinical studies using MRF. The authors also discuss their clinical experiences as well as recommendations for optimal results. MRF using the Thermage CPT system (Solta Medical, Hayward, California) offers minimal downtime with a favorable side-effect profile. Although there are many radiofrequency devices on the market for aesthetic use, MRF has the most clinical trials to date to support its use as an effective, evidence-based modality to improve rhytids and tighten the skin. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. Percutaneous Ablation in the Kidney

    PubMed Central

    Wood, Bradford J.; Gervais, Debra A.

    2011-01-01

    Percutaneous ablation in the kidney is now performed as a standard therapeutic nephron-sparing option in patients who are poor candidates for resection. Its increasing use has been largely prompted by the rising incidental detection of renal cell carcinomas with cross-sectional imaging and the need to preserve renal function in patients with comorbid conditions, multiple renal cell carcinomas, and/or heritable renal cancer syndromes. Clinical studies to date indicate that radiofrequency ablation and cryoablation are effective therapies with acceptable short- to intermediate-term outcomes and with a low risk in the appropriate setting, with attention to pre-, peri-, and postprocedural detail. The results following percutaneous radiofrequency ablation and cryoablation in the treatment of renal cell carcinoma are reviewed in this article, including those of several larger scale studies of ablation of T1a tumors. Clinical and technical considerations unique to ablation in the kidney are presented, and potential complications are discussed. © RSNA, 2011 PMID:22012904

  2. Transarterial embolization (TAE) as add-on to percutaneous radiofrequency ablation (RFA) for the treatment of renal tumors: Review of the literature, overview of state-of-the-art embolization materials and further perspective of advanced image-guided tumor ablation.

    PubMed

    Sommer, C M; Pallwein-Prettner, L; Vollherbst, D F; Seidel, R; Rieder, C; Radeleff, B A; Kauczor, H U; Wacker, F; Richter, G M; Bücker, A; Rodt, T; Massmann, A; Pereira, P L

    2017-01-01

    Percutaneous radiofrequency ablation (RFA) for the treatment of stage I renal cell carcinoma has recently gained significant attention as the now available long-term and controlled data demonstrate that RFA can result in disease-free and cancer-specific survival comparable with partial and/or radical nephrectomy. In the non-controlled single center trials, however, the rates of treatment failure vary. Operator experience and ablation technique may explain some of the different outcomes. In the controlled trials, a major limitation is the lack of adequate randomization. In case reports, original series and overview articles, transarterial embolization (TAE) before percutaneous RFA was promising to increase tumor control and to reduce complications. The purpose of this study was to systematically review the literature on TAE as add-on to percutaneous RFA for renal tumors. Specific data regarding technique, tumor and patient characteristics as well as technical, clinical and oncologic outcomes have been analyzed. Additionally, an overview of state-of-the-art embolization materials and the radiological perspective of advanced image-guided tumor ablation (TA) will be discussed. In conclusion, TAE as add-on to percutaneous RFA is feasible and very effective and safe for the treatment of T1a tumors in difficult locations and T1b tumors. Advanced radiological techniques and technologies such as microwave ablation, innovative embolization materials and software-based solutions are now available, or will be available in the near future, to reduce the limitations of bland RFA. Clinical implementation is extremely important for performing image-guided TA as a highly standardized effective procedure even in the most challenging cases of localized renal tumors.

  3. Radiofrequency Identification

    PubMed Central

    Jones, Terry L.

    2017-01-01

    A national campaign is underway to increase the amount of time staff nurses spend at the bedside of hospitalized patients through redesign of the work environment. This kind of work redesign requires robust data depicting what nurses do and how they spend their time. Historically, these kinds of data have been difficult, costly, and time consuming to collect. Wireless capture of data on the movement of humans within the work environment (ie, time and motion) is now possible through radiofrequency identification technology. When small tracking devices the size of a quarter are affixed to their clothing, the movement of nurses throughout a patient care unit can be monitored. The duration and frequency of patient interaction are captured along with the duration of time spent in other locations of interest to include nurses’ station, supply room, medication room, doctors’ station, electronic documentation stations, family waiting rooms, and the hallway. Patterns of nurse movement and time allocation can be efficiently identified, and the effects of staffing practices, workflows, and unit layout evaluated. Integration of radiofrequency identification time and motion data with other databases enables nurse leaders to link nursing time to important cost and quality outcomes. Nurse leaders should explore the usefulness of radiofrequency identification technology in addressing data needs for nurse time and motion. PMID:22592451

  4. Percutaneous Tracheostomy

    PubMed Central

    Mehta, Chitra; Mehta, Yatin

    2017-01-01

    Percutaneous dilatational tracheostomy (PDT) is a commonly performed procedure in critically sick patients. It can be safely performed bedside by intensivists. This has resulted in decline in the use of surgical tracheostomy in intensive care unit (ICU) except in few selected cases. Most common indication of tracheostomy in ICU is need for prolonged ventilation. About 10% of patients requiring at least 3 days of mechanical ventilator support get tracheostomised during ICU stay. The ideal timing of PDT remains undecided at present. Contraindications and complications become fewer with increase in experience. Various methods of performing PDT have been discovered in last two decades. Preoperative work up, patient selection and post tracheostomy care form key components of a successful PDT. Bronchoscopy and ultrasound have been found to be useful procedural adjuncts, especially in presence of unfavorable anatomy. This article gives a brief overview about the use of PDT in ICU. PMID:28074819

  5. Percutaneous tracheostomy.

    PubMed

    Mehta, Chitra; Mehta, Yatin

    2017-01-01

    Percutaneous dilatational tracheostomy (PDT) is a commonly performed procedure in critically sick patients. It can be safely performed bedside by intensivists.This has resulted in decline in the use of surgical tracheostomy in intensive care unit (ICU) except in few selected cases. Most common indication of tracheostomy in ICU is need for prolonged ventilation. About 10% of patients requiring at least 3 days of mechanical ventilator support get tracheostomised during ICU stay. The ideal timing of PDT remains undecided at present. Contraindications and complications become fewer with increase in experience. Various methods of performing PDT have been discovered in last two decades. Preoperative work up, patient selection and post tracheostomy care form key components of a successful PDT. Bronchoscopy and ultrasound have been found to be useful procedural adjuncts, especially in presence of unfavorable anatomy. This article gives a brief overview about the use of PDT in ICU.

  6. Treatment of bone tumours by radiofrequency thermal ablation.

    PubMed

    Santiago, Fernando Ruiz; Del Mar Castellano García, María; Montes, Jose Luis Martínez; García, Manuel Ruiz; Fernández, Juan Miguel Tristán

    2009-03-01

    Radiofrequency thermal ablation (RFTA) is considered the treatment of choice for osteoid osteomas, in which it has long been safely used. Other benign conditions (chondroblastoma, osteoblastoma, giant cell tumour, etc.) can also be treated by this technique, which is less invasive than traditional surgical procedures. RFTA ablation is also an option for the palliation of localized, painful osteolytic metastatic and myeloma lesions. The reduction in pain improves the quality of life of patients with cancer, who often have multiple morbidities and a limited life expectancy. In some cases, these patients are treated with RFTA because conventional therapies (surgery, radiotherapy, chemotherapy, etc.) have been exhausted. In other cases, it is combined with conventional therapies or other percutaneous treatments, e.g., cementoplasty, offering faster pain relief and bone strengthening. A multidisciplinary approach to the management of these patients is recommended to select the optimal treatment, including orthopaedic surgeons, neurosurgeons, medical and radiation oncologists and interventional radiologists.

  7. [Cosmetic radiofrequency].

    PubMed

    Huth, J

    2010-01-01

    Cosmetic radio frequency uses an electric current of high frequency that generates heat through the subcutaneous tissues enough to break the collagen fibers and allow synthesis of a neo-collagen. It permits cutaneous resurfacing, improving the tone and quality of the skin (wrinkles and enlarged pores), and delicately reshaping facial volumes. The principle of a type Ellman monopolar radiofrequency at a rate of 4 MHz Pellevé, Surgitron Dual RF S 5 is described. Its use inclines more towards anti-aging and natural rejuvenation of the face, neck and neckline. It may be associated with other rejuvenation techniques such as fillers and botulinum toxin within certain time limits.

  8. [Treatment of trigeminal neuralgia: an update and future prospects of percutaneous techniques].

    PubMed

    Bescós, Agustín; Pascual, Vicenç; Escosa-Bage, Marcos; Malaga, Xavier

    2015-08-01

    Trigeminal neuralgia is one of the most severe facial pain syndromes. The annual incidence varies between 4-13% and has a significant effect on patients' quality of life. When the pain cannot be controlled by pharmacological treatment, several different surgical options can be considered. The choice of technique will be based on observational studies and its application depends on the experience of each centre. To assess the effectiveness and level of evidence of pharmacological and surgical treatment in trigeminal neuralgia, and to analyse the current role of percutaneous techniques in the treatment of this pathology. The initial treatment of trigeminal neuralgia is pharmacological and carbamazepine is the only drug with a sufficiently high level of evidence. The percutaneous surgical techniques are effective and easy to apply, but the tendency for relapses to appear means there is a preference for vascular microdecompression. Yet, there are no reports of comparative studies that determine the superiority of a technique with a good level of evidence. The three most commonly used percutaneous techniques, balloon compression, glycerol rhizotomy and thermocoagulation by radiofrequency, were reviewed. This last technique is the one that has undergone the greatest development in recent years, with the emergence of neurophysiological techniques that make it possible to optimise results. The selection of a surgical technique for use in trigeminal neuralgia does not have much backing from randomised clinical trials. The new procedures in the application of radiofrequency can improve the treatment prospects of this pathology.

  9. Stepwise case selection using Guy's stone score reduces complications during percutaneous nephrolithotomy training

    PubMed Central

    Jaipuria, Jiten; Suryavanshi, Manav; Desai, Amitsinh P.; Goyal, Sanjay; Patel, Kaushal; Parhad, Sandip S.; Subudhi, Santosh K.; Rao, Chandrashekar V.; Kumar, Satish P.; Sen, Tridib K.

    2017-01-01

    Introduction: Traditional percutaneous nephrolithotomy (PCNL) training involved subjective award of cases to the trainee. We restructured this according to the Guy's stone score (GSS) such that each trainee stepwise completed 25 cases of each grade before progressing. This study compares the outcomes of training with traditional versus stepwise approach. Methods: Four hundred consecutive cases equally distributed for two trainees in each group were compared in terms of complications (Clavien-Dindo), stone free rate (SFR), operative and fluoroscopy time. External comparison was also done against a benchmark surgeon. Multivariable regression model was created to compare SFR and complications while adjusting for comorbidity, Amplatz size, access tract location, number of punctures, body mass index, stone complexity, and training approach. Results: The distribution of cases in terms of calculus complexity was similar. Overall, in comparison to traditional training, stepwise training had significantly shorter median operative time (100 vs. 120 min, P < 0.05), fluoroscopy time (136 vs. 150 min, P < 0.05) and fewer overall (29.5% vs. 43.5%, P < 0.005) as well as major complications (3% vs. 8.5%, P - 0.029), though initial SFR was higher but not statistically significant (77% vs. 71.5%). On multivariable analyses, stepwise training was independently associated with lower complications (odds ratio 0.46 [0.20–0.74], P - 0.0013) along with GSS grade, number of punctures, and Amplatz size. Stepwise training had similar fluoroscopy time, major complications and final clearance rate compared to expert surgeon. Conclusions: PCNL has a learning curve specific for each grade of calculus complexity and stepwise training protocol improves outcomes. PMID:28197029

  10. Treatment selection for urolithiasis: percutaneous nephrolithomy, ureteroscopy, shock wave lithotripsy, and active monitoring.

    PubMed

    Desai, Mahesh; Sun, Yinghao; Buchholz, Noor; Fuller, Andrew; Matsuda, Tadashi; Matlaga, Brian; Miller, Nicole; Bolton, Damien; Alomar, Mohammad; Ganpule, Arvind

    2017-03-16

    Urolithiasis is a significant worldwide source of morbidity, constituting a common urological disease that affects between 10 and 15% of the world population. Recent technological and surgical advances have replaced the need for open surgery with less invasive procedures. The factors which determine the indications for percutaneous nephrolithotomy include stone factors (stone size, stone composition, and stone location), patient factors (habitus and renal anomalies), and failure of other treatment modalities (ESWL and flexible ureteroscopy). The accepted indications for PCNL are stones larger than 20 mm(2), staghorn and partial staghorn calculi, and stones in patients with chronic kidney disease. The contraindications for PCNL include pregnancy, bleeding disorders, and uncontrolled urinary tract infections. Flexible ureteroscopy can be one of the options for lower pole stones between 1.5 and 2 cm in size. This option should be exercised in cases of difficult lower polar anatomy and ESWL-resistant stones. Flexible ureteroscopy can also be an option for stones located in the diverticular neck or a diverticulum. ESWL is the treatment to be discussed as a option in all patient with renal stones (excluding lower polar stones) between size 10 and 20 mm. In addition, in lower polar stones of size between 10 and 20 mm if the anatomy is favourable, ESWL is the option. In proximal ureteral stones, ESWL should be considered as a option with flexible ureteroscopy Active monitoring has a limited role and can be employed in post-intervention (PCNL or ESWL) residual stones, in addition, asymptomatic patients with no evidence of infection and fragments less than 4 mm can be monitored actively.

  11. Therapy of HCC-radiofrequency ablation.

    PubMed

    Buscarini, L; Buscarini, E

    2001-01-01

    Radiofrequency interstitial hyperthermia has been used for percutaneous ablation of hepatocellular carcinoma, under ultrasound guidance in local anesthesia. Conventional needle electrodes require a mean number of 3 sessions to treat tumors of diameter < or = 3 cm. Tumors up to 3.5 cm in diameter can be treated in 1 or 2 sessions by expandable needle electrodes. With both methods in all treated cases, ablation of tumors was obtained. In a group of patients with long follow-up, survival rate at 5 years was 40%. In a mean follow-up of 23 months 41% of patients had recurrences (local recurrences in 5%; new lesions in 36%), which often could be retreated by a new course of radiofrequency application. In recent experience large hepatocellular carcinomas (up to 6.8 cm in diameter) were treated by a combination of segmental transcatheter arterial embolization followed by radiofrequency application. In this way most tumors were ablated in one session of radiofrequency therapy. No fatal complications were observed. Major complications were: strong pain due to capsular necrosis in one patient; hemotorax in one case; a fluid collection in the site of ablated tumor in one patient treated by combination of transcatheter arterial embolization and radiofrequency application.

  12. Prospective study of ultrasound-guided percutaneous renal cryotherapy: case selection as an optimization factor for a technique.

    PubMed

    Rodríguez-Faba, O; Palou, J; Rosales, A; de la Torre, P; Martí, J; Palazzetti, A; Villavicencio, H

    2015-01-01

    To evaluate the technical and oncological effectiveness of ultrasound-guided percutaneous renal cryotherapy (PRC) in a selected group of patients with renal cancer. We conducted a prospective study of 28 patients with posterior-facing T1a renal tumors with middle and inferior external borders. All patients underwent ultrasound-guided PRC. Follow-up was conducted with computed tomography at 1 month and then every 6 months, with a good result defined as the total absence of contrast incorporation. We performed a descriptive and survival study using the Kaplan-Meier estimator. The 28 patients had a mean age (SD) of 68.3 (10.1) years, and the group underwent 28 procedures. The mean (SD) size of the tumors was 25.5 (7.5) mm, the mean nephrometry score was 1.41 (0.52) and the mean preoperative creatinine level was 133.5 (144.1) mmol/L. There were no intraoperative complications. In terms of postoperative complications, there was only 1 case (3.5%) of a skin lesion resulting from treating a tumor in a transplanted kidney (Clavien II). The median follow-up was 25 months, and the mean (SD) postoperative creatinine level was 135.5 (110.3) mmol/L. Two cases presented radiological recurrence (93% efficacy), with a mean time to recurrence of 12 and 19 months, respectively. There were no tumor-related deaths. Our series (the largest on PRC in our country to date) shows that, with an appropriate selection of tumors, PRC is a safe technique with minimal morbidity. Ultrasonography enables the controlled performance of the procedure and saves the patient from radiation and reduces costs. Copyright © 2013 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  13. A Comparison of Transjugular and Plugged-Percutaneous Liver Biopsy in Patients with Contraindications to Ordinary Percutaneous Liver Biopsy and an 'In-House' Protocol for Selecting the Procedure of Choice

    SciTech Connect

    Atar, Eli; Ben Ari, Ziv; Bachar, Gil N.; Amlinski, Yelena; Neyman, Chaim; Knizhnik, Michael; Litvin, Sergey; Schmilovitz-Weiss, Hemda; Shapiro, Riki; Bruckhaimer, Elchanan; Tur-Kaspa, Ran; Belenky, Alexander

    2010-06-15

    The purpose of this study was to evaluate the effectiveness and safety of transjugular liver biopsy (TJLB) and plugged-percutaneous liver biopsy (PB) in consecutive patients with severe liver disease associated with impaired coagulation, ascites, or both and to verify the in-house protocol used to select the appropriate procedure. In 2000-2006, 329 patients (208 male [62.8%] and 121 female [37.2%]), aged 1 month to 81 years (mean, 46.8 years), underwent 150 TJLBs (39.1%) or 233 PBs (60.9%) procedures at a major tertiary center, as determined by an in-house protocol. The groups were compared for specimen characteristics, technical success, and complications. Technical success rates were 97.4% for TJLB (146/150) and 99.1% for PB (231/233). TJLB was associated with a lower average core length (1.29 vs. 1.43 cm) and lower average number of specimens obtained (2.44 vs. 2.8), but both methods yielded sufficient tissue for a definitive diagnosis. There were no major complications in either group. TJLB and PB can be safely and effectively performed for the diagnosis of hepatic disease in patients with contraindications for standard percutaneous liver biopsy. When both are technically available, we suggest PB as the procedure of choice, especially in transplanted livers.

  14. A comparison of transjugular and plugged-percutaneous liver biopsy in patients with contraindications to ordinary percutaneous liver biopsy and an "in-house" protocol for selecting the procedure of choice.

    PubMed

    Atar, Eli; Ben Ari, Ziv; Bachar, Gil N; Amlinski, Yelena; Neyman, Chaim; Knizhnik, Michael; Litvin, Sergey; Schmilovitz-Weiss, Hemda; Shapiro, Riki; Bruckhaimer, Elchanan; Tur-Kaspa, Ran; Belenky, Alexander

    2010-06-01

    The purpose of this study was to evaluate the effectiveness and safety of transjugular liver biopsy (TJLB) and plugged-percutaneous liver biopsy (PB) in consecutive patients with severe liver disease associated with impaired coagulation, ascites, or both and to verify the in-house protocol used to select the appropriate procedure. In 2000-2006, 329 patients (208 male [62.8%] and 121 female [37.2%]), aged 1 month to 81 years (mean, 46.8 years), underwent 150 TJLBs (39.1%) or 233 PBs (60.9%) procedures at a major tertiary center, as determined by an in-house protocol. The groups were compared for specimen characteristics, technical success, and complications. Technical success rates were 97.4% for TJLB (146/150) and 99.1% for PB (231/233). TJLB was associated with a lower average core length (1.29 vs. 1.43 cm) and lower average number of specimens obtained (2.44 vs. 2.8), but both methods yielded sufficient tissue for a definitive diagnosis. There were no major complications in either group. TJLB and PB can be safely and effectively performed for the diagnosis of hepatic disease in patients with contraindications for standard percutaneous liver biopsy. When both are technically available, we suggest PB as the procedure of choice, especially in transplanted livers.

  15. Thermal Protection during Percutaneous Thermal Ablation of Renal Cell Carcinoma

    PubMed Central

    Kam, Anthony W.; Littrup, Peter J.; Walther, McClellan M.; Hvizda, Julia; Wood, Bradford J.

    2008-01-01

    Thermal injury to collateral structures is a known complication of thermal ablation of tumors. The authors present the use of CO2 dissection and inserted balloons to protect the bowel during percutaneous radiofrequency (RF) ablation and cryotherapy of primary and locally recurrent renal cell carcinoma. These techniques offer the potential to increase the number of tumors that can be treated with RF ablation or cryotherapy from a percutaneous approach. PMID:15231890

  16. Safety and Feasibility of Outpatient Percutaneous Coronary Intervention in Selected Patients: A Spanish Multicenter Registry.

    PubMed

    Córdoba-Soriano, Juan G; Jiménez-Mazuecos, Jesús; Rivera Juárez, Allan; Gutiérrez-Díez, Antonio; Gutiérrez Ibañes, Enrique; Samaniego-Lampón, Beatriz; Lozano, Iñigo; Gallardo-López, Arsenio; Díaz, Leonel; Sanz-Ruiz, Ricardo; Melehi, Driss; Barrionuevo-Sánchez, María Isabel; Rondán-Murillo, Juan; Vegas-Valle, José M; Elízaga, Jaime

    2017-07-01

    The exponential increase in coronary interventions plus the generalization of the radial approach represent the ideal scenario for starting outpatient angioplasty programs with the aim of reducing the costs while maintaining safety. This article reports data from a multicenter Spanish registry on fully ambulatory transradial angioplasty in selected patients for the first time. Prospective registry of elective outpatient transradial-ulnar angioplasty in patients with stable coronary disease. Patients were discharged the same day and were followed up at 24hours and 30 days. Safety and feasibility were analyzed. Of the 723 patients included (76% male; age, 66.6±10.5 years), 533 (73.7%) were finally discharged after 4 to 12hours of surveillance. Among the remaining 190 (26.7%) patients, the most common reason for hospitalization was clinical instability after the procedure (60.5%). Independent predictors of admission were a history of peripheral artery disease, a higher baseline creatinine level, ad hoc performance of the procedure, and multivessel disease. At 24hours, there was 1 major adverse event in 1 patient (0.19%), who required hospitalization for major bleeding not related to vascular access. At 30 days, there were 3 major adverse events (0.56%): 1 subacute stent thrombosis, 1 revascularization of a vessel other than the treated vessel, and 1 minor stroke. Eight patients (1.5%) required admission at 30 days. The application of an outpatient transradial-ulnar angioplasty program with discharge after 4 to 12 hours' surveillance is safe and feasible in well-selected patients. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  17. Percutaneous cryoablation for hepatocellular carcinoma

    PubMed Central

    Song, Kyoung Doo

    2016-01-01

    Local ablation therapy is considered as a conventional treatment option for patients with early stage hepatocellular carcinoma (HCC). Although radiofrequency (RF) ablation is widely used for HCC, the use of cryoablation has been increasing as newer and safer cryoablation systems have developed. The thermodynamic mechanism of freezing and thawing used in cryoablation is the Joule-Thomson effect. Cryoablation destroys tissue via direct tissue destruction and vascular-related injury. A few recent comparative studies have shown that percutaneous cryoablation for HCCs is comparable to percutaneous RF ablation in terms of long term therapeutic outcomes and complications. Cryoablation has several advantages over RF ablation such as well visualization of iceball, no causation of severe pain, and lack of severe damage to great vessels and gallbladder. It is important to know the advantages and disadvantages of cryoablation compared with RF ablation for improvement of therapeutic efficacy and safety. PMID:28081593

  18. Gain of Imaging Fidelity by Employing a Higher Number of Independent Transmit Channels Together with Slice-Selective Radio-Frequency (RF) Shimming at 7T

    PubMed Central

    Darji, Niravkumar; Patel, Gopesh; Speck, Oliver

    2014-01-01

    Dielectric resonance effects and radio-frequency (RF) power deposition have become challenging issues for magnetic resonance imaging at ultrahigh-field (UHF) strengths. The use of transmit (Tx) coil arrays with independently-driven RF sources using a parallel transmission system is a promising method for alleviating the resulting RF inhomogeneities. In this study, the effect on homogeneity and RF-power when employing a higher number of transmit channels with multi-slice acquisition in vivo at high field strength (7T) is scrutinized. An 8-channel head coil array was driven to emulate circular polarized (CP) and 2-, 4-, and 8-channel independent transmit configurations at 7T. Static RF shimming was employed on human subjects in order to homogenize the B1+ field in the excited volume. Slice-selective and global RF shimming methods were applied with CP and 2-, 4-, and 8-channel transmit channel configurations. RF shimming was performed from CP to 2-, 4-, and 8-channel Tx configurations globally and slice-selectively. Systematic improvement in B1+ homogeneity and/or reduction in RF-power were observed. RF shimming in the human brain with 8-channel transmit and slice-selective shimming yields an increase in B1+ homogeneity of 43% and/or reduces RF-power by 68% when compared with CP global RF shimming at 7T. PMID:28788438

  19. One-year follow-up results of intradiscal diode laser, radiofrequency, and pulsed radiofrequency therapies: a retrospective study.

    PubMed

    Ökmen, Korgün; Metin Ökmen, Burcu

    2017-01-01

    This study aims to investigate the efficacy of three different percutaneous intradiscal therapies in patients with chronic low back pain (CLBP) due to lumbar disc herniation (LDH). Medical files of a total of 120 patients who received percutaneous intradiscal therapy were retrospectively analyzed. All patients were divided into three groups: group L: diode laser (n = 40), group R: radiofrequency (RF) (n = 40), and group P: pulsed radiofrequency (PRF) (n = 40). The visual analogue scale (VAS) and Oswestry Disability Index (ODI) scores were calculated at 1, 3, 6, and 12 months for all patients. One-year follow-up results were as follows: group L: pre-treatment (PreT) VAS 5.6 ± -1, ODI 37.6 ± -4.7, post-treatment 12th month (PT12) VAS 2.8 ± -1.4, ODI 14.1 ± -7.1; group P: PreT VAS 6.0 ± 1, ODI 37.5 ± 5.9, PT12 VAS 3.1 ± 1.3, ODI 20.3 ± 17.0; and group R: PreT VAS 5.6 ± 1.0, ODI 37.9 ± 4.7, PT12 VAS 3.3 ± 1.4, ODI 27.2 ± 14.1. In each of the three groups, there was a statistically significant reduction in the VAS and ODI scores at 1, 3, 6, and 12 months, compared to the baseline values (p < 0.05). The highest reduction in the VAS and ODI scores was observed in group L, whereas the lowest reduction was in group R. We consider that in groups with patient selection criteria at our study; diode laser, RF, and PRF, which are administered using the percutaneous intradiscal route for CLBP patients diagnosed with LDH, may be used as an alternative treatment option.

  20. Enhanced full-face skin rejuvenation using synchronous intense pulsed optical and conducted bipolar radiofrequency energy (ELOS): introducing selective radiophotothermolysis.

    PubMed

    Sadick, Neil S; Alexiades-Armenakas, Macrene; Bitter, Patrick; Hruza, George; Mulholland, R Stephen

    2005-01-01

    The authors previously reported their experience achieving non-ablative skin enhancement with serial, full-face, intense pulsed light treatments in a large series of patients. A new method for skin renewal electro-optical synergy (ELOS), which combines intense pulsed optical energy and conducted bipolar radiofrequency (RF) energy into a single pulse, has been recently introduced. Intense pulsed optical energy and bipolar RF energy have been used in dermatologic surgery for many years; however, this study represents the therapeutic impact of the combined energies. The authors report their experience using an ELOS system (Aurora SR, Syneron, Yokneam, Israel) on 108 consecutive patients treated with a series of full-face procedures. Patients received 5 full-face treatments every 3 weeks. Each treatment consisted of 1 to 8 full-face and segmental passes. The number of passes, specific wavelength of pulsed optical energy, and RF energy were determined by the patient's skin type, dyschromia, wrinkle pathology, and presence of a tan. A total of 540 treatments were performed on 108 subjects. All patients had pre- and post-procedural photographs. Results were assessed by double-blinded physician photographic evaluation and patient satisfaction scales. Overall skin improvement was rated at 75.3%. Overall average wrinkle improvement was 41.2%, with an average Class 1 wrinkle improvement of 64.7%, Class 2 wrinkle improvement of 38.6%, and Class 3 wrinkle improvement of 20.4%. Improvement in skin laxity was rated at 62.9%. Skin texture was reported to improve 74.1%. Improvement in the appearance of pore size was rated at 65.1%. Average improvement in erythema and telangiectasia was 68.4%. Average improvement in hyperpigmentation and dyschromia was 79.3%. Overall patient satisfaction was 92%. The overall minor complication rate, including blistering, crusting, and stripping was 8.3%, and the major complication rate was less than 1%. One small, depressed nasal scar was observed

  1. Endovenous radiofrequency ablation of superficial and perforator veins.

    PubMed

    Roth, Steven M

    2007-10-01

    Radiofrequency ablation of superficial and perforator veins for venous insufficiency has emerged as a leading alternative to traditional vein stripping operations. This percutaneous technique can be performed in less than an hour using local anesthetic or sedation. The VNUS Closure catheters (VNUS Medical Technologies, San Jose, California) work by resistive heating in the vein wall that is constantly monitored through a feedback loop to the VNUS Closure generator. Side effects are less than with other endovenous ablation techniques and patients resume normal activity immediately. The new ClosureFAST catheter is an important advancement that combines the speed of endovenous laser ablation with the expected fewer side effects of radiofrequency ablation.

  2. Fast Slice-Selective Radio-Frequency Excitation Pulses for Mitigating B1+ Inhomogeneity in the Human Brain at 7 Tesla

    PubMed Central

    Zelinski, Adam C.; Wald, Lawrence L.; Setsompop, Kawin; Alagappan, Vijayanand; Gagoski, Borjan A.; Goyal, Vivek K.; Adalsteinsson, Elfar

    2008-01-01

    A novel radio-frequency (RF) pulse design algorithm is presented that generates fast slice-selective excitation pulses that mitigate B1+ inhomogeneity present in the human brain at high field. The method is provided an estimate of the B1+ field in an axial slice of the brain and then optimizes the placement of sinc-like “spokes” in kz via an L1-norm penalty on candidate (kx, ky) locations; an RF pulse and gradients are then designed based on these weighted points. Mitigation pulses are designed and demonstrated at 7T in a head-shaped water phantom and the brain; in each case, the pulses mitigate a significantly non-uniform transmit profile and produce nearly uniform flip angles across the field of excitation (FOX). The main contribution of this work, the sparsity-enforced spoke placement and pulse design algorithm, is derived for conventional single-channel excitation systems and applied in the brain at 7T, but readily extends to lower field systems, nonbrain applications, and multichannel parallel excitation arrays. PMID:18506800

  3. Superconductive radiofrequency window assembly

    DOEpatents

    Phillips, H.L.; Elliott, T.S.

    1998-05-19

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The SRF window assembly has a superconducting metal-ceramic design. The SRF window assembly comprises a superconducting frame, a ceramic plate having a superconducting metallized area, and a superconducting eyelet for sealing plate into frame. The plate is brazed to eyelet which is then electron beam welded to frame. A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the SRF window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator. 11 figs.

  4. Superconducting radiofrequency window assembly

    DOEpatents

    Phillips, H.L.; Elliott, T.S.

    1997-03-11

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly has a superconducting metal-ceramic design. The srf window assembly comprises a superconducting frame, a ceramic plate having a superconducting metallized area, and a superconducting eyelet for sealing plate into frame. The plate is brazed to eyelet which is then electron beam welded to frame. A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator. 11 figs.

  5. Percutaneous ablation of benign bone tumors.

    PubMed

    Welch, Brian T; Welch, Timothy J

    2011-09-01

    Percutaneous image-guided ablation has become a standard of practice and one of the primary modalities for treatment of benign bone tumors. Ablation is most commonly used to treat osteoid osteomas but may also be used in the treatment of chondroblastomas, osteoblastomas, and giant cell tumors. Percutaneous image-guided ablation of benign bone tumors carries a high success rate (>90% in case series) and results in decreased morbidity, mortality, and expense compared with traditional surgical methods. The ablation technique most often applied to benign bone lesions is radiofrequency ablation. Because the ablation technique has been extensively applied to osteoid osteomas and because of the uncommon nature of other benign bone tumors, we will primarily focus this discussion on the percutaneous ablation of osteoid osteomas.

  6. Radiofrequency Ablation of Liver Tumors

    MedlinePlus

    ... Other equipment such as needle electrodes, an electrical generator and grounding pads may also be used. Radiofrequency ... retractable electrodes that extend when needed. The radiofrequency generator produces electrical currents in the range of radiofrequency ...

  7. [Techniques for percutaneous access during percutaneous nephrolithotomy.

    PubMed

    Pérez-Fentes, Daniel

    2017-01-01

    The creation of the access is one of the main steps in percutaneous nephrolithotomy, the most complicated for many urologists and the one that limited most the universalization of the technique. From a purely technical point of view, it includes puncture of the excretory tract and dilatation of the percutaneous tract to end with the introduction of an Amplatz type working sheath. The objective of the puncture is to try to access the excretory system through the renal papilla, minimizing the risk of bleeding. The puncture may be guided by ultrasound, fluoroscopy, both, under endoscopic or laparoscopic control, by CT scan or MRI, or even by application of new technologies (Robotic, augmented reality, electromagnetic navigation,...). Due to the versatility and independence involved in having the ability to perform the renal puncture in the operative room, as well as its influence in the results of PCNL, it must be the urologist himself who performs this basic step of percutaneous surgery. The tract may be dilated by Alken type metallic dilators, semirrigid Amplatz type dilators or high pressure balloons. To date, there is no single ideal dilatation method, being the selection based on the endourologist's experience and the knowledge of the advantages and limitations of each option. The objective of this review is to present the main methods for puncture guiding and tract dilatation for PCNL, as well as to provide technical details to improve its result.

  8. Intralesional radiofrequency in venous malformations.

    PubMed

    Garg, S; Kumar, S; Singh, Y B

    2015-03-01

    Venous malformations are usually asymptomatic and managed conservatively. Treatment, in the form of laser, sclerotherapy, or resection, is needed only if lesions present with symptoms or cosmetic deformity. The aim of this study was to find out how effective radiofrequency ablation was in patients with incomplete or unsatisfactory resolution of a venous malformation after an intralesional injection of bleomycin. During the 5 year period 2008-2012, we organised a prospective, clinical study at a tertiary care centre. Patients were selected from the outpatient department of the Lady Hardinge Medical College and associated hospitals, New Delhi, India. Five patients with venous malformations were treated by intralesional injection of bleomycin in a dose of 0.5U/kg body weight, which was repeated every 2 weeks for a total of 8 injections. They then had multiple intralesional radiofrequency ablation every 2 months until a satisfactory outcome was achieved. After the initial 8 doses the reduction in the size of the lesions was minimal (less than 50%). After 2-4 applications of radiofrequency ablation there was appreciable reduction in the size of the lesions (about 80%) with good functional and cosmetic outcomes. Radiofrequency ablation is an effective adjunct for patients with venous malformations of the head and neck that have not responded satisfactorily to intralesional injection of bleomycin. To our knowledge radiofrequency ablation after intralesional injection of bleomycin has not previously been described as a treatment for venous malformations. Copyright © 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  9. The Use of Color-Coded Duplex Scanning in the Selection of Patients with Lower Extremity Arterial Disease for Percutaneous Transluminal Angioplasty: A Prospective Study

    SciTech Connect

    Elsman, Bernard H.P.; Legemate, Dink A.; Heyden, Frank W.H.M. van der; Vos, Henk de; Mali, Willem P.T.M.; Eikelboom, Bert C.

    1996-09-15

    Purpose: To exploit the potential benefits of percutaneous transluminal angioplasty (PTA) in patients with short obstructive lesions in the lower extremity, it is preferable to select patients suitable for PTA before proceeding to hospital admission and angiography. The aim of this prospective study was to evaluate the role of color-coded duplex scanning in the correct selection of patients for PTA and its influence on planning the approach to the lesion. Methods: On the basis of clinical history, physical examination, pressure indices, and ultrasound duplex scanning, 109 patients were scheduled for PTA. Results: The indication for PTA was correct in 103 patients (94%), while the procedure was performed successfully in 98 patients (90%). The approach to the lesion was planned successfully in the majority of patients. Conclusion: This study shows that it is justifiable to plan PTA on the basis of information obtained by duplex scanning. Results of the duplex scan may guide the catheterization route.

  10. Stereotactic Radiofrequency Ablation of Unresectable Intrahepatic Cholangiocarcinomas: A Retrospective Study

    SciTech Connect

    Haidu, Marion; Dobrozemsky, Georg; Schullian, Peter Widmann, Gerlig; Klaus, Alexander Weiss, Helmut Margreiter, Raimund; Bale, Reto

    2012-10-15

    Purpose: To evaluate treatment effects, complications, and outcome of percutaneous stereotactic radiofrequency ablation (SRFA) of intrahepatic cholangiocarcinoma (ICC). Patients and Methods: Eleven consecutive patients (nine men and two women) with a total of 36 inoperable ICCs (18 initial lesions, 16 lesions newly detected during follow-up, and two local recurrences) underwent SRFA between December 2004 and June 2010. Two different radiofrequency ablation (RFA) devices with internally cooled electrodes were used. Tumor diameters ranged from 0.5 to 10 cm (median 3.0 cm). A total of 23 SRFA sessions were performed. The efficacy of SRFA was evaluated by contrast-enhanced computed tomography or magnetic resonance imaging 1 month after treatment and then every 3 months. Results: Primary technical effectiveness rate was 92%. Further follow-up every 3 months revealed three local recurrences (8%), two of which were successfully retreated, resulting in a secondary technical effectiveness rate of 98%. After a total of 23 RFA sessions, three major complications occurred (13%) that could be managed interventionally. Mean follow-up time was 35 months (range 12-81 months). One- and 3-year overall survival rates were 91 and 71%, respectively. The median overall survival was 60 months (according to the life table method). Eight (73%) of 11 patients were still alive at the end of follow-up. Conclusion: SRFA is effective in the treatment of unresectable ICC even if the tumor is large and located close to major vessels. SRFA shows a survival benefit compared to other palliative treatment options and may also be considered as the first-line local treatment of ICCs in selected patients.

  11. Diaphragmatic Hernia After Radiofrequency Ablation for Hepatocellular Carcinoma

    SciTech Connect

    Yamagami, Takuji Yoshimatsu, Rika; Matsushima, Shigenori; Tanaka, Osamu; Miura, Hiroshi; Nishimura, Tsunehiko

    2011-02-15

    We describe a 71-year-old woman with a hepatocellular carcinoma who underwent percutaneous radiofrequency ablation (RF) with a single internally cooled electrode under computed tomography (CT) fluoroscopic guidance. Nine months after the procedure, CT images showed herniation of the large intestine into the right pleural cavity. To our knowledge this complication of RF performed with a single internally cooled electrode under CT guidance has not been previously reported.

  12. Small tip angle three-dimensional tailored radiofrequency slab-select pulse for reduced B1 inhomogeneity at 3 T.

    PubMed

    Saekho, Suwit; Boada, Fernando E; Noll, Douglas C; Stenger, V Andrew

    2005-02-01

    This work presents a small tip-angle 3D tailored RF slab-select pulse for reducing the B1 field inhomogeneity at 3T. The compensated slice profile was determined from a B1 inhomogeneity map. SNR improvement and degree of artifact reduction were evaluated in a NiCl2 doped phantom and human brains. The technique was found to reduce inhomogeneities as large as 30% of the peak image magnitude in all three spatial directions in the brain using a standard head coil.

  13. Selection criteria for radiofrequency ablation for colorectal liver metastases in the era of effective systemic therapy: a clinical score based proposal

    PubMed Central

    2014-01-01

    Background At present, there are no widely accepted criteria for the use of radiofrequency ablation (RFA) for the treatment of colorectal liver metastases (CLM) in the context of effective modern-agent therapies. We aimed to define selection criteria for patients with liver-limited CLM who may benefit from adding RFA to systemic therapy with respect to long-term disease control. Methods Between 2002 and 2007, 88 consecutive patients received RFA for liver-only CLM during partial remission (PR), stable disease (SD), or progressive disease (PD) after systemic therapy. At a median follow-up of 8.2 years (range 5.2-11.1 years), clinical data were correlated to overall survival (OS) and recurrence-free survival (RFS). Results Poor OS and RFS correlated significantly with PD to systemic therapy before RFA (HR 5.46; p < 0.0001; and HR 6.46; p < 0.0001), number of ≥4 CLM (HR 3.13; p = 0.0005; and HR 1.77; p = 0.0389), and carcinoembryonic antigen (CEA) level of ≥100 ng/ml (HR 1.67; p = 0.032; and HR 1.67; p = 0.044). The presence of four criteria (PR, ≤3 CLM, ≤3 cm maximum size, and CEA ≤100 ng/ml) selected a subgroup (n = 23) with significantly higher probabilities for OS and RFS at 5 years (39% and 22%,respectively) compared to those without any or up 3 of these criteria (0-27% and 0-9%, p < 0.001, respectively). Conclusions A score based on four criteria (response to systemic therapy, ≤3 CLM, ≤3 cm size, low CEA value) may allow to select patients with liver-only CLM for whom additional use of RFA most likely adds benefit in an attempt to achieve long-term disease control. Almost one-fourth of patients fulfilling these four criteria may achieve 5-year survival without disease recurrence following effective systemic plus local RFA treatment. PMID:25016394

  14. Percutaneous connectors

    NASA Technical Reports Server (NTRS)

    Picha, G. J.; Taylor, S. R.

    1981-01-01

    A surface possessing a regular array of micro-pillars was evaluated with regard to its ability to control epithelial downgrowth at the percutaneous interface. A range of pillar sizes were applied to the vertical segment of T shaped Biomer (R) implants. These percutaneous tabs were implanted into the dorsum of cats for a period of 6 weeks using a standardized surgical technique. Comments were made post-operatively and at the time of retrieval. A quantitative scoring system was applied to these observations as well as histological results. As observed, the pillar morphology used displayed the ability to control epithelial downgrowth. Collagen ingrowth into the interpillar spaces and possibly direct interactions of the epithelial cells with the morphology may account for the inhibition. The reproducibility of epithelial inhibition is, however, limited by other factors which are currently not well understood. These factors and potential methods of assessment are discussed.

  15. Percutaneous arthrodesis.

    PubMed

    Lauge-Pedersen, Henrik

    2003-02-01

    It has been generally accepted that residual cartilage and subchondral bone has to be removed in order to get bony fusion in arthrodeses. In 1998 we reported successful fusion of 11 rheumatoid ankles, all treated with percutaneous fixation only. In at least one of these ankle joint there was cartilage left. This was confirmed by arthrotomy in order to remove an osteophyte, which hindered dorsiflexion. More than 25 rheumatoid patients with functional alignment in the ankle joint have subsequently been operated on with the percutaneous technique, and so far we have had only one failure. Patients with rheumatoid arthritis are known to sometimes fuse at least their subtalar joints spontaneously, and the destructive effect of the synovitis on the cartilage could contribute to fusion when using the percutaneous technique. In a rabbit study we therefore tested the hypothesis that even a normal joint can fuse merely by percutaneous fixation. The patella was fixated to the femur with lag screw technique without removal of cartilage, and in 5 of 6 arthrodeses with stable fixation bony fusion followed. Depletion of synovial fluid seemed to be the mechanism behind cartilage disappearance. The stability of the fixation achieved at arthrodesis surgery is an important factor in determining success or failure. Dowel arthrodesis without additional fixation proved to be deleterious. A good fit of the bone surfaces appears necessary. In the ankle joint, it would be technically demanding to retain the arch-shaped geometry of the joint after resection of the cartilage. Normally the joint surfaces are resected to produce flat osteotomy surfaces that are thus easier to fit together, encouraging healing to occur. On the other hand it is considered an advantage to preserve as much subchondral bone as possible, as the strong subchondral bone plate can contribute to the stability of the arthrodesis. Ankle arthrodesis can be successfully performed in patients with rheumatoid arthritis by

  16. Measurement of creatine kinase reaction rate in human brain using magnetization transfer image-selected in vivo spectroscopy (MT-ISIS) and a volume ³¹P/¹H radiofrequency coil in a clinical 3-T MRI system.

    PubMed

    Jeong, Eun-Kee; Sung, Young-Hoon; Kim, Seong-Eun; Zuo, Chun; Shi, Xianfeng; Mellon, Eric A; Renshaw, Perry F

    2011-08-01

    High-energy phosphate metabolism, which allows the synthesis and regeneration of adenosine triphosphate (ATP), is a vital process for neuronal survival and activity. In particular, creatine kinase (CK) serves as an energy reservoir for the rapid buffering of ATP levels. Altered CK enzyme activity, reflecting compromised high-energy phosphate metabolism or mitochondrial dysfunction in the brain, can be assessed using magnetization transfer (MT) MRS. MT (31)P MRS has been used to measure the forward CK reaction rate in animal and human brain, employing a surface radiofrequency coil. However, long acquisition times and excessive radiofrequency irradiation prevent these methods from being used routinely for clinical evaluations. In this article, a new MT (31)P MRS method is presented, which can be practically used to measure the CK forward reaction rate constant in a clinical MRI system employing a volume head (31)P coil for spatial localization, without contamination from the scalp muscle, and an acquisition time of 30 min. Other advantages associated with the method include radiofrequency homogeneity within the regions of interest of the brain using a volume coil with image-selected in vivo spectroscopy localization, and reduction of the specific absorption rate using nonadiabatic radiofrequency pulses for MT saturation. The mean value of k(f) was measured as 0.320 ± 0.075 s(-1) from 10 healthy volunteers with an age range of 18-40 years. These values are consistent with those obtained using earlier methods, and the technique may be used routinely to evaluate energetic processes in the brain on a clinical MRI system. Copyright © 2010 John Wiley & Sons, Ltd.

  17. In vitro assessment of a combined radiofrequency ablation and cryo-anchoring catheter for treatment of mitral valve prolapse.

    PubMed

    Boronyak, Steven M; Merryman, W David

    2014-03-21

    Percutaneous approaches to mitral valve repair are an attractive alternative to surgical repair or replacement. Radiofrequency ablation has the potential to approximate surgical leaflet resection by using resistive heating to reduce leaflet size, and cryogenic temperatures on a percutaneous catheter can potentially be used to reversibly adhere to moving mitral valve leaflets for reliable application of radiofrequency energy. We tested a combined cryo-anchoring and radiofrequency ablation catheter using excised porcine mitral valves placed in a left heart flow loop capable of reproducing physiologic pressure and flow waveforms. Transmitral flow and pressure were monitored during the cryo-anchoring procedure and compared to baseline flow conditions, and the extent of radiofrequency energy delivery to the mitral valve was assessed post-treatment. Long term durability of radiofrequency ablation treatment was assessed using statically treated leaflets placed in a stretch bioreactor for four weeks. Transmitral flow and pressure waveforms were largely unaltered during cryo-anchoring. Parameter fitting to mechanical data from leaflets treated with radiofrequency ablation and cryo-anchoring revealed significant mechanical differences from untreated leaflets, demonstrating successful ablation of mitral valves in a hemodynamic environment. Picrosirius red staining showed clear differences in morphology and collagen birefringence between treated and untreated leaflets. The durability study indicated that statically treated leaflets did not significantly change size or mechanics over four weeks. A cryo-anchoring and radiofrequency ablation catheter can adhere to and ablate mitral valve leaflets in a physiologic hemodynamic environment, providing a possible percutaneous alternative to surgical leaflet resection of mitral valve tissue.

  18. Local Recurrence After Hepatic Radiofrequency Coagulation

    PubMed Central

    Mulier, Stefaan; Ni, Yicheng; Jamart, Jacques; Ruers, Theo; Marchal, Guy; Michel, Luc

    2005-01-01

    Objective: The purpose of this study was to analyze the factors that influence local recurrence after radiofrequency coagulation of liver tumors. Summary Background Data: Local recurrence rate varies widely between 2% and 60%. Apart from tumor size as an important risk factor for local recurrence, little is known about the impact of other factors. Methods: An exhaustive literature search was carried out for the period from January 1, 1990 to January 1, 2004. Only series with a minimal follow-up of 6 months and/or mean follow-up of 12 months were included. Univariate and multivariate meta-analyses were carried out. Results: Ninety-five independent series were included, allowing the analysis of the local recurrence rate of 5224 treated liver tumors. In a univariate analysis, tumor-dependent factors with significantly less local recurrences were: smaller size, neuroendocrine metastases, nonsubcapsular location, and location away from large vessels. Physician-dependent favorable factors were: surgical (open or laparoscopic) approach, vascular occlusion, general anesthesia, a 1-cm intentional margin, and a greater physician experience. In a multivariate analysis, significantly less local recurrences were observed for small size (P < 0.001) and a surgical (versus percutaneous) approach (P < 0.001). Conclusions: Radiofrequency coagulation by laparoscopy or laparotomy results in superior local control, independent of tumor size. The percutaneous route should mainly be reserved for patients who cannot tolerate a laparoscopy or laparotomy. The short-term benefits of less invasiveness for the percutaneous route do not outweigh the longer-term higher risk of local recurrence. PMID:16041205

  19. Radiofrequency ablation for renal tumors: our experience.

    PubMed

    Hiraoka, Kenji; Kawauchi, Akihiro; Nakamura, Terukazu; Soh, Jintetsu; Mikami, Kazuya; Miki, Tsuneharu

    2009-11-01

    To report our results of percutaneous radiofrequency ablation (RFA) for renal tumors and to assess predictors of therapeutic efficacy. Forty patients (median age 73 years) with renal tumors were treated with RFA under local or epidural anesthesia. All of them had high surgical risk or refused radical surgery. Tumors were punctured percutaneously using the Radionics Cool-tip RF System under computed tomography or ultrasonographic guidance. Median tumor diameter was 24 mm. After RFA, contrast-enhanced computed tomography or magnetic resonance imaging was performed within 1 month. Complete response (CR) was defined as no enhancement inside the tumor. Factors related to the outcome and to renal function were assessed. Median follow up was 16 months. CR was observed in 34 cases (85.0%). A significant difference in CR rate was observed between tumors < or =30 mm and those >30 mm. Outcomes tended to be better for tumors in the mid to lower kidney, and those away from the renal hilum. Recurrence was observed in one case (2.9%), but a CR was obtained again by additional RFA. Out of a total of 77 RFA procedures, complications occurred in only three cases (3.9%), and conservative treatment was possible in all cases. Serum creatinine levels 3 months after RFA did not differ from those before RFA. Percutaneous RFA is a safe and effective treatment for small renal tumors in patients with high surgical risk or who refuse radical surgery.

  20. Radiofrequency Ablation of Intrahepatic Cholangiocarcinoma: Preliminary Experience

    SciTech Connect

    Carrafiello, Gianpaolo Lagana, Domenico; Cotta, Elisa; Mangini, Monica; Fontana, Federico; Bandiera, Francesca; Fugazzola, Carlo

    2010-08-15

    The purpose of this study was to evaluate the safety and efficacy of percutaneous ultrasound (US)-guided radiofrequency ablation (RFA) in patients with intrahepatic cholangiocarcinoma (ICCA) in a small, nonrandomized series. From February 2004 to July 2008, six patients (four men and two women; mean age 69.8 years [range 48 to 83]) with ICCA underwent percutaneous US-guided RFA. Preintervetional transarterial embolization was performed in two cases to decrease heat dispersion during RFA in order to increase the area of ablation. The efficacy of RFA was evaluated using contrast-enhanced dynamic computed tomography (CT) 1 month after treatment and then every 3 months thereafter. Nine RFA sessions were performed for six solid hepatic tumors in six patients. The duration of follow-up ranged from 13 to 21 months (mean 17.5). Posttreatment CT showed total necrosis in four of six tumors after one or two RFA sessions. Residual tumor was observed in two patients with larger tumors (5 and 5.8 cm in diameter). All patients tolerated the procedure, and there with no major complications. Only 1 patient developed post-RFA syndrome (pain, fever, malaise, and leukocytosis), which resolved with oral administration of acetaminophen. Percutaneous RFA is a safe and effective treatment for patients with hepatic tumors: It is ideally suited for those who are not eligible for surgery. Long-term follow-up data regarding local and systemic recurrence and survival are still needed.

  1. Quality Improvement Guidelines for Radiofrequency Ablation of Liver Tumours

    SciTech Connect

    Crocetti, Laura; Baere, Thierry de; Lencioni, Riccardo

    2010-02-15

    The development of image-guided percutaneous techniques for local tumour ablation has been one of the major advances in the treatment of liver malignancies. Among these methods, radiofrequency ablation (RFA) is currently established as the primary ablative modality at most institutions. RFA is accepted as the best therapeutic choice for patients with early-stage hepatocellular carcinoma (HCC) when liver transplantation or surgical resection are not suitable options [1, 2]. In addition, RFA is considered a viable alternate to surgery (1) for inoperable patients with limited hepatic metastatic disease, especially from colorectal cancer, and (2) for patients deemed ineligible for surgical resection because of extent and location of the disease or concurrent medical conditions [3]. These guidelines were written to be used in quality-improvement programs to assess RFA of HCC and liver metastases. The most important processes of care are (1) patient selection, (2) performing the procedure, and (3) monitoring the patient. The outcome measures or indicators for these processes are indications, success rates, and complication rates.

  2. Percutaneous ablation of pancreatic cancer

    PubMed Central

    D’Onofrio, Mirko; Ciaravino, Valentina; De Robertis, Riccardo; Barbi, Emilio; Salvia, Roberto; Girelli, Roberto; Paiella, Salvatore; Gasparini, Camilla; Cardobi, Nicolò; Bassi, Claudio

    2016-01-01

    Pancreatic ductal adenocarcinoma is a highly aggressive tumor with an overall 5-year survival rate of less than 5%. Prognosis and treatment depend on whether the tumor is resectable or not, which mostly depends on how quickly the diagnosis is made. Chemotherapy and radiotherapy can be both used in cases of non-resectable pancreatic cancer. In cases of pancreatic neoplasm that is locally advanced, non-resectable, but non-metastatic, it is possible to apply percutaneous treatments that are able to induce tumor cytoreduction. The aim of this article will be to describe the multiple currently available treatment techniques (radiofrequency ablation, microwave ablation, cryoablation, and irreversible electroporation), their results, and their possible complications, with the aid of a literature review. PMID:27956791

  3. Clinic Predictive Factors for Insufficient Myocardial Reperfusion in ST-Segment Elevation Myocardial Infarction Patients Treated with Selective Aspiration Thrombectomy during Primary Percutaneous Coronary Intervention.

    PubMed

    Tian, Jinfan; Liu, Yue; Song, Xiantao; Zhang, Min; Xu, Feng; Yuan, Fei; Lyu, Shuzheng

    2016-01-01

    Background. Insufficient data are available on the potential benefit of selective aspiration and clinical predictors for no-reflow in STEMI patients undergoing primary percutaneous coronary intervention (PPCI) adjunct with aspiration thrombectomy. Objective. The aim of our study was to investigate clinical predictors for insufficient reperfusion in patients with high thrombus burden treated with PPCI and manual aspiration thrombectomy. Methods. From January 2011 till December 2015, 277 STEMI patients undergoing manual aspiration thrombectomy and PPCI were selected and 202 patients with a Thrombolysis in Myocardial Infarction (TIMI) thrombus grade 4~5 were eventually involved in our study. According to a cTFC value, patients were divided into Group I (cTFC > 40), namely, insufficient reperfusion group; Group II (cTFC ≤ 40), namely, sufficient reperfusion group. Results. Univariate analysis showed that hypertension, multivessel disease, time from symptom to PCI (≧4.8 hours), and postaspiration cTFC > 40 were negative predictors for insufficient reperfusion. After multivariate adjustment, age ≧ 60 years, hypertension, time from symptom to PCI (≧4.8 hours), and postaspiration cTFC > 40 were independently associated with insufficient reperfusion in STEMI patients treated with manual aspiration thrombectomy. Upfront intracoronary GP IIb/IIIa inhibitor (Tirofiban) was positively associated with improved myocardial reperfusion. Conclusion. Fully identifying risk factors will help to improve the effectiveness of selective thrombus aspiration.

  4. Clinic Predictive Factors for Insufficient Myocardial Reperfusion in ST-Segment Elevation Myocardial Infarction Patients Treated with Selective Aspiration Thrombectomy during Primary Percutaneous Coronary Intervention

    PubMed Central

    Song, Xiantao; Zhang, Min; Xu, Feng; Yuan, Fei

    2016-01-01

    Background. Insufficient data are available on the potential benefit of selective aspiration and clinical predictors for no-reflow in STEMI patients undergoing primary percutaneous coronary intervention (PPCI) adjunct with aspiration thrombectomy. Objective. The aim of our study was to investigate clinical predictors for insufficient reperfusion in patients with high thrombus burden treated with PPCI and manual aspiration thrombectomy. Methods. From January 2011 till December 2015, 277 STEMI patients undergoing manual aspiration thrombectomy and PPCI were selected and 202 patients with a Thrombolysis in Myocardial Infarction (TIMI) thrombus grade 4~5 were eventually involved in our study. According to a cTFC value, patients were divided into Group I (cTFC > 40), namely, insufficient reperfusion group; Group II (cTFC ≤ 40), namely, sufficient reperfusion group. Results. Univariate analysis showed that hypertension, multivessel disease, time from symptom to PCI (≧4.8 hours), and postaspiration cTFC > 40 were negative predictors for insufficient reperfusion. After multivariate adjustment, age ≧ 60 years, hypertension, time from symptom to PCI (≧4.8 hours), and postaspiration cTFC > 40 were independently associated with insufficient reperfusion in STEMI patients treated with manual aspiration thrombectomy. Upfront intracoronary GP IIb/IIIa inhibitor (Tirofiban) was positively associated with improved myocardial reperfusion. Conclusion. Fully identifying risk factors will help to improve the effectiveness of selective thrombus aspiration. PMID:27891513

  5. Superconductive radiofrequency window assembly

    DOEpatents

    Phillips, Harry Lawrence; Elliott, Thomas S.

    1998-01-01

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly (20) has a superconducting metal-ceramic design. The srf window assembly (20) comprises a superconducting frame (30), a ceramic plate (40) having a superconducting metallized area, and a superconducting eyelet (50) for sealing plate (40) into frame (30). The plate (40) is brazed to eyelet (50) which is then electron beam welded to frame (30). A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator.

  6. Superconducting radiofrequency window assembly

    DOEpatents

    Phillips, Harry L.; Elliott, Thomas S.

    1997-01-01

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly (20) has a superconducting metal-ceramic design. The srf window assembly (20) comprises a superconducting frame (30), a ceramic plate (40) having a superconducting metallized area, and a superconducting eyelet (50) for sealing plate (40) into frame (30). The plate (40) is brazed to eyelet (50) which is then electron beam welded to frame (30). A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator.

  7. Long-term bioeffects of 435-MHz radiofrequency radiation on selected blood-borne endpoints in cannulated rats. Volume 6. Cardiovascular studies. Final report, October 1982-June 1985

    SciTech Connect

    Popovic, V.P.; Toler, J.C.; Bonasera, S.J.; Popovic, P.P.; Honeycutt, C.B.

    1988-01-01

    Two hundred adult male white rats with chronically implanted aortic cannulas were randomly divided into 2 groups. Animals in the first group were exposed to low-level pulsed-wave 435-MHz radiofrequency radiation for approximately 22 hours daily, 7 days a week, for 6 months. Animals in the second group were maintained under identical conditions but were not radiated. The cannulas were used to record heart rate and arterial blood pressure in unrestrained, unanesthetized rats. Statistical analysis of the results did not indicate any increase in heart rate or arterial blood pressure of RFR-exposed animals when compared to sham-exposed animals. Thus, chronic exposure to the low-level radiofrequency environment did not induce stress that was manifested as increases in heart rate or mean arterial blood pressure. This result correlated with the conclusion of a previous report demonstrating no RFR effects on plasma norepinephrine and epinephrine concentrations in the group of rats.

  8. Radiofrequency thermocoagulation combined with pulsed radiofrequency helps relieve postoperative complications of trigeminal neuralgia.

    PubMed

    Zhao, W-X; Wang, Q; He, M-W; Yang, L-Q; Wu, B-S; Ni, J-X

    2015-07-13

    Trigeminal neuralgia is a sudden, severe condition characterized by stabbing and recurrent pain. Radiofrequency thermocoagulation (RFT) and pulsed radiofrequency (PRF) are common surgical interventions used to treat trigeminal neuralgia. This study aimed to investigate the therapeutic effects and associated complications of a combination of RFT and PRF in the treatment of trigeminal neuralgia. Computed tomography-guided percutaneous RFT of the Gasserian ganglion was performed on 80 patients with trigeminal neuralgia. Patients were randomly assigned to either group A (RFT at 70°C) or group B (RFT at 75°C). Patients in each group were divided into 2 subgroups, receiving percutaneous RFT (240 s) with or without PRF (42°C, 2 Hz, 240 s). Six months later, pain relief and complication status were evaluated. There was no significant difference in visual analogue scores among groups with RFT at 70° or 75°C, with or without PRF. Data showed that facial numbness and postoperative masticatory muscle weakness recovered more rapidly in patients receiving combined RFT and PRF treatment. Decreased corneal reflex was relieved to a significantly greater extent in groups receiving PRF than those without. Thus, compared to the use of RFT at 75°C alone, the combination of PRF and RFT helped eliminate postoperative complications, such as facial numbness, masticatory muscle weakness, and decreased corneal reflex, indicating that it could be useful for surgically treating trigeminal neuralgia.

  9. Aesthetic Applications of Radiofrequency Devices.

    PubMed

    Sadick, Neil; Rothaus, Kenneth O

    2016-07-01

    Radiofrequency (RF)-based devices are used to improve face and neck laxity, a major feature of aging that until recently could only be addressed with surgery. Although these treatments are not meant to replace surgical procedures, patient satisfaction studies have been consistently high. For physicians offering these skin rejuvenation procedures, it is essential to have intimate knowledge of how the devices work, select appropriate candidates, set realistic expectations, and combine treatments to optimize outcomes. This article discusses the various noninvasive RF technologies currently in use and reviews pertinent clinical studies evaluating their efficacy and safety. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Recent developments in percutaneous mitral valve treatment.

    PubMed

    La Canna, Giovanni; Denti, Paolo; Buzzatti, Nicola; Alfieri, Ottavio

    2016-01-01

    In recent years, various percutaneous techniques have been introduced for the treatment of mitral regurgitation (MR), including direct leaflet repair, annuloplasty and left ventricular remodeling. Percutaneous mitral repair targets both primary degenerative and secondary mitral valve regurgitation and may be considered in selected high-surgical-risk patients. The assessment of mitral functional anatomy by echocardiography and computed tomography is crucial when selecting the appropriate repair strategy, according to the regurgitant valve lesion and the surrounding anatomy. The ongoing clinical use of new devices in annuloplasty and percutaneous mitral valve replacement is a promising new scenario in the treatment of MR that goes beyond the conventional surgical approach.

  11. A comparison of pulsed radiofrequency and continuous radiofrequency on thermocoagulation of egg white in vitro.

    PubMed

    Heavner, James E; Boswell, Mark V; Racz, Gabor B

    2006-04-01

    Clinical studies have demonstrated the efficacy of pulsed radiofrequency (PRF). PRF energy is delivered to neural structures via specifically designed, percutaneously placed needles to treat some chronic pain states. PRF was introduced as a non-destructive alternative to destructive lesioning produced by continuous radiofrequency (CRF) energy. However, there is an ongoing controversy regarding the potential tissue-destructive effects of PRF used for pain management. To evaluate the ability of PRF to coagulate egg white at various temperatures used clinically and to compare with CRF. A commercially available (TYCO-Radionics Labs) 5 cm, 22G (0.7 mm) SMK needle with 5 mm active tip was inserted into a 10 mL test tube containing raw egg white at 37 degrees C and the tip was heated up to 80 degrees C. The photographic patterns of thermocoagulation of egg white in vitro produced by continuous and pulsed radiofrequency (RF) were compared and the lowest temperature at which PRF produced thermocoagulation was determined. Pulsed RF produced barely detectable thermocoagulation at 60 degrees C. Above 60 degrees C, the pattern of coagulation produced by PRF resembled that observed with CRF. However, the density and size of the coagulation ball appeared somewhat greater with CRF. PRF coagulated egg white at temperatures above 60degrees C in a manner similar to CRF. Monitoring needle tip temperature using the thermode supplied with the needle during PRF and keeping the recorded tip temperature below 60degrees C may minimize unwanted thermal destruction of tissue.

  12. Palliative Radiofrequency Ablation for Recurrent Prostate Cancer

    SciTech Connect

    Jindal, Gaurav; Friedman, Marc; Locklin, Julia Wood, Bradford J.

    2006-06-15

    Percutaneous radiofrequency ablation (RFA) is a minimally invasive local therapy for cancer. Its efficacy is now becoming well documented in many different organs, including liver, kidney, and lung. The goal of RFA is typically complete eradication of a tumor in lieu of an invasive surgical procedure. However, RFA can also play an important role in the palliative care of cancer patients. Tumors which are surgically unresectable and incompatible for complete ablation present the opportunity for RFA to be used in a new paradigm. Cancer pain runs the gamut from minor discomfort relieved with mild pain medication to unrelenting suffering for the patient, poorly controlled by conventional means. RFA is a tool which can potentially palliate intractable cancer pain. We present here a case in which RFA provided pain relief in a patient with metastatic prostate cancer with pain uncontrolled by conventional methods.

  13. Radiofrequency thermal ablation of hepatocellular carcinoma.

    PubMed

    Allgaier, H P; Galandi, D; Zuber, I; Blum, H E

    2001-01-01

    Hepatocellular carcinoma (HCC) is one of the major malignancies worldwide. Due to advanced or decompensated liver cirrhosis, comorbidity and multicentricity of the tumor lesions, 70-80% of HCC patients are inoperable at the time of diagnosis. Radiofrequency thermal ablation (RFTA) is a new minimally invasive and sage technique for the nonsurgical treatment of HCCs. Similar to other ablation techniques, the treatment strategy depends on several factors, including the patient's clinical status, the stage of liver cirrhosis and of the HCC. RFTA can be performed percutaneously, laparoscopically or after laparotomy. Advanced RFTA equipment, refined techniques of modifying tumor tissue response to RFTA, and combined treatment strategies should lead to better response rates even in larger HCCs.

  14. Current Status of Percutaneous Endografting

    PubMed Central

    Patel, Parag J.; Kelly, Quinton; Hieb, Robert A.; Lee, Cheong Jun

    2015-01-01

    Totally percutaneous endovascular abdominal aortic aneurysm repair (PEVAR) using suture-mediated closure devices (SMCDs) has several well-established advantages over standard open femoral exposure as a direct consequence of being less invasive and having shorter times to hemostasis and procedure completion. The first multicenter randomized controlled trial designed to assess the safety and efficacy of PEVAR and to compare percutaneous access with standard open femoral exposure was recently published (the PEVAR trial). The PEVAR trial demonstrated that percutaneous endografting is safe, effective, and noninferior to standard open femoral exposure among trained operators. The study reaffirmed the results of several recent single center and nonrandomized studies, demonstrating that percutaneous access facilitated shorter procedures, shorter times to secure hemostasis, and improved quality of life for patients. As PEVAR has gained popularity among patients and physicians, refinements to the technique and patient selection process have been made. There has been growing interest in treating patients with anatomical characteristics previously thought to be unsuitable for PEVAR, such as common femoral artery (CFA) calcifications, scarred groins, small CFA diameter, and high patient body mass index (BMI). However, observance of strict procedural technique and consideration for patient selection criteria remain paramount in achieving acceptable technical success rates with PEVAR. PMID:26327747

  15. Tips and tricks for a safe and effective image-guided percutaneous renal tumour ablation.

    PubMed

    Mauri, Giovanni; Nicosia, L; Varano, G M; Bonomo, G; Della Vigna, P; Monfardini, L; Orsi, F

    2017-06-01

    Image-guide thermal ablations are nowadays increasingly used to provide a minimally invasive treatment to patients with renal tumours, with reported good clinical results and low complications rate. Different ablative techniques can be applied, each with some advantages and disadvantages according to the clinical situation. Moreover, percutaneous ablation of renal tumours might be complex in cases where there is limited access for image guidance or a close proximity to critical structures, which can be unintentionally injured during treatment. In the present paper we offer an overview of the most commonly used ablative techniques and of the most important manoeuvres that can be applied to enhance the safety and effectiveness of percutaneous image-guided renal ablation. Emphasis is given to the different technical aspects of cryoablation, radiofrequency ablation, and microwave ablation, on the ideal operating room setting, optimal image guidance, application of fusion imaging and virtual navigation, and contrast enhanced ultrasound in the guidance and monitoring of the procedure. Moreover, a series of protective manoeuvre that can be used to avoid damage to surrounding sensitive structures is presented. A selection of cases of image-guided thermal ablation of renal tumours in which the discussed technique were used is presented and illustrated. • Cryoablation, radiofrequency and microwave ablation have different advantages and disadvantages. • US, CT, fusion imaging, and CEUS increase an effective image-guidance. • Different patient positioning and external compression may increase procedure feasibility. • Hydrodissection and gas insufflation are useful to displace surrounding critical structures. • Cold pyeloperfusion can reduce the thermal damage to the collecting system.

  16. Percutaneous techniques for cervical pain of discal origin.

    PubMed

    Gangi, Afshin; Tsoumakidou, Georgia; Buy, Xavier; Cabral, Jose Facundo; Garnon, Julien

    2011-04-01

    Cervical discogenic pain is an important cause of suffering and disability in the adult population. Pain management in cervical disc herniation relies initially on conservative care (rest, physiotherapy, and oral medications). Once conservative treatment has failed, different percutaneous minimally invasive radiological procedures can be applied to relief pain. This article offers a systematic review on the percutaneous minimally invasive techniques that can be advocated for the treatment of cervical pain of discal origin. Periradicular steroid injection under image guidance (computed tomography or magnetic resonance imaging) is the first technique to be considered. The steroid injection aims at reducing the periradicular inflammation and thus relieves the radicular pain. The steroid injections present satisfying short-term results, but pain can recur in the long term. Whenever the steroid injections fail to relieve pain from a contained cervical disc herniation, the more invasive percutaneous disc decompression techniques should be proposed. Percutaneous radiofrequency nucleoplasty is the most often applied technique on the cervical level with a low risk of thermal damage. When the indications and instructions are respected, radiofrequency nucleoplasty presents accepted safety and efficacy levels.

  17. Remote Thermometry to Avoid Complications in Radiofrequency Ablation

    PubMed Central

    Diehn, Felix E.; Neeman, Ziv; Hvizda, Julie L.; Wood, Bradford J.

    2008-01-01

    Percutaneous image-guided radiofrequency ablation (RFA) of tumors has the potential risk for thermal damage to nearby normal collateral tissues. Thus, the goal of creating a sufficient area of tumor necrosis must be weighed against the risk for injury to collateral tissues. In this study, remote thermistors were used to monitor temperatures near collateral structures during tumor RFA. Four unique cases are described. When temperature-sensitive structures are near the target lesion, remote thermometry could further increase the safety of this evolving minimally invasive procedure. PMID:14654495

  18. Managing turbinate hypertrophy: coblation vs. radiofrequency treatment.

    PubMed

    Passali, D; Loglisci, M; Politi, L; Passali, G C; Kern, E

    2016-06-01

    The role of inferior turbinate hypertrophy in the reduction of nasal airflow is well established. Although chronic nasal obstruction is not life- threatening, it significantly impairs patients' quality of life, affecting many aspects of daily activities; therefore, patients seek medical intervention. 40 patients were selected (27 males and 13 females) between 27 and 64 years of age with a symptom of nasal obstruction. The patients were divided in two groups: Group 1: coblation, 25 patients (18 males and 7 females); Group 2: radiofrequency, 15 patients (7 males and 6 females). These 40 patients were followed for 3 years. Patients were analyzed using both subjective and objective methods. The visual analog scale (VAS) subjective data and objective data including both active anterior rhinomanometry and acoustic rhinometry were recorded and analyzed. Data were collected pre-operatively and at 1 and 3 years post-operatively. According to our data, both coblation and radiofrequency turbinate reduction benefit patients with good results. The complications, found during the follow-up, are limited to minimal bleeding and crusting. Coblation and radiofrequency were significantly less painful than others procedures during the early post-operative period. In our study, both coblation and radiofrequency provide an improvement in nasal airflow with a reduction in nasal obstructive symptoms in the short term, but their efficacy tended to decrease within 3 years.

  19. Combined MRI and Fluoroscopic Guided Radiofrequency Ablation of a Renal Tumor

    SciTech Connect

    Fotiadis, Nikolas I.; Sabharwal, Tarun; Gangi, Afshin; Adam, Andreas

    2009-01-15

    Percutaneous CT- and ultrasound-guided radiofrequency ablation of renal cell carcinoma (RCC) has been shown to have very promising medium-term results. We present a unique case of recurrent RCC after partial nephrectomy in a patient with a single kidney and impaired renal function. This tumor could not be visualized either with CT or with ultrasound. A combination of magnetic resonance imaging and fluoroscopic guidance was used, to the best of our knowledge for the first time, to ablate the tumor with radiofrequency. The patient was cancer-free and off dialysis at 30-month follow up.

  20. Combined use of selective intracoronary thrombolysis and percutaneous transluminal coronary angioplasty for the treatment of coronary obstruction.

    PubMed

    Keltai, M; Kádár, A; Palik, I; Rózsa, Z

    1984-01-01

    The case of a young female patient with inferior infarction is presented. In the fifth hour after the onset of MI coronary angiography revealed complete obstruction of the right coronary artery. This obstruction has been recanalized by selective intracoronary infusion of streptokinase. At the site of occlusion there remained a 90% coronary stenosis, causing anginal attacks. By means of balloon-catheter angioplasty the stenosis was reduced to less than 50%. The coronary angioplasty resulted in an improvement of left ventricular function, physical working capacity and cessation of anginal attacks.

  1. [Experience of radiofrequency ablation therapy for hepatocellular carcinoma].

    PubMed

    Iwauchi, Takehiko; Yamada, Nobuya; Amano, Ryousuke; Ohira, Masaichi; Nishino, Hiroji; Hirakawa, Kosei

    2005-10-01

    There are various therapeutic options for hepatocellular carcinoma. Radiofrequency ablation (RFA) was introduced to Japan in 1998, and has become popular in percutaneous local treatment for HCC as a treatment with the advantage of both percutaneous ethanol injection therapy and percutaneous microwave coagulation therapy. In this study, we investigated the efficacy and complication of RFA for HCC. Seventeen patients underwent percutaneous or open RFA with a Cool-tip needle (Radionics Co. Ltd) from April 2001 to May 2005. All tumors were solitary and the average diameter of 17 tumors was 2.24 cm. Fifteen tumors were completely ablated, but two weren't. Local recurrence occurred in only one patient and the rate of local recurrence was 6.7%. Mild complication occurred in some patients, but critical complication did not occur in any patients. In this study, it was considered that RFA could be performed safely and was a good treatment for HCC with high efficacy. After investigating the long-term results and indication of RFA, it was suggested that RFA might be reestablished as an effective treatment for HCC.

  2. Radiofrequency Ablation of Cancer

    SciTech Connect

    Friedman, Marc; Mikityansky, Igor; Kam, Anthony; Libutti, Steven K.; Walther, McClellan M.; Neeman, Ziv; Locklin, Julia K.; Wood, Bradford J.

    2004-09-15

    Radiofrequency ablation (RFA) has been used for over 18 years for treatment of nerve-related chronic pain and cardiac arrhythmias. In the last 10 years, technical developments have increased ablation volumes in a controllable, versatile, and relatively inexpensive manner. The host of clinical applications for RFA have similarly expanded. Current RFA equipment, techniques, applications, results, complications, and research avenues for local tumor ablation are summarized.

  3. Radiofrequency Ablation of Cancer

    PubMed Central

    Friedman, Marc; Mikityansky, Igor; Kam, Anthony; Libutti, Steven K.; Walther, McClellan M.; Neeman, Ziv; Locklin, Julia K.; Wood, Bradford J.

    2008-01-01

    Radiofrequency ablation (RFA) has been used for over 18 years for treatment of nerve-related chronic pain and cardiac arrhythmias. In the last 10 years, technical developments have increased ablation volumes in a controllable, versatile, and relatively inexpensive manner. The host of clinical applications for RFA have similarly expanded. Current RFA equipment, techniques, applications, results, complications, and research avenues for local tumor ablation are summarized. PMID:15383844

  4. Evaluation of renal nerve morphological changes and norepinephrine levels following treatment with novel bipolar radiofrequency delivery systems in a porcine model

    PubMed Central

    Cohen-Mazor, Meital; Mathur, Prabodh; Stanley, James R.L.; Mendelsohn, Farrell O.; Lee, Henry; Baird, Rose; Zani, Brett G.; Markham, Peter M.; Rocha-Singh, Krishna

    2014-01-01

    Objective: To evaluate the safety and effectiveness of different bipolar radiofrequency system algorithms in interrupting the renal sympathetic nerves and reducing renal norepinephrine in a healthy porcine model. Methods: A porcine model (N = 46) was used to investigate renal norepinephrine levels and changes to renal artery tissues and nerves following percutaneous renal denervation with radiofrequency bipolar electrodes mounted on a balloon catheter. Parameters of the radiofrequency system (i.e. electrode length and energy delivery algorithm), and the effects of single and longitudinal treatments along the artery were studied with a 7-day model in which swine received unilateral radiofrequency treatments. Additional sets of animals were used to examine norepinephrine and histological changes 28 days following bilateral percutaneous radiofrequency treatment or surgical denervation; untreated swine were used for comparison of renal norepinephrine levels. Results: Seven days postprocedure, norepinephrine concentrations decreased proportionally to electrode length, with 81, 60 and 38% reductions (vs. contralateral control) using 16, 4 and 2-mm electrodes, respectively. Applying a temperature-control algorithm with the 4-mm electrodes increased efficacy, with a mean 89.5% norepinephrine reduction following a 30-s treatment at 68°C. Applying this treatment along the entire artery length affected more nerves vs. a single treatment, resulting in superior norepinephrine reduction 28 days following bilateral treatment. Conclusion: Percutaneous renal artery application of bipolar radiofrequency energy demonstrated safety and resulted in a significant renal norepinephrine content reduction and renal nerve injury compared with untreated controls in porcine models. PMID:24875181

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

    PubMed

    Hoffer, Fredric A; Daw, Najat C; Xiong, Xiaoping; Anghelescu, Doralina; Krasin, Matthew; Yan, Xiaowei; Davidoff, Andrew M; Furman, Wayne L; Rodriguez-Galindo, Carlos; Spunt, Sheri L

    2009-03-15

    This prospective study was designed to be the first to evaluate the toxicity of radiofrequency ablation (RFA) in patients with recurrent pediatric solid tumors. 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. 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. 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. Copyright (c) 2009 American Cancer Society.

  6. Pulsed radiofrequency for occipital neuralgia.

    PubMed

    Manolitsis, Nicholas; Elahi, Foad

    2014-01-01

    The clinical application of pulsed radiofrequency (PRF) by interventional pain physicians for a variety of chronic pain syndromes, including occipital neuralgia, is growing. As a minimally invasive percutaneous technique with none to minimal neurodestruction and a favorable side effect profile, use of PRF as an interventional neuromodulatory chronic pain treatment is appealing. Occipital neuralgia, also known as Arnold's neuralgia, is defined by the International Headache Society as a paroxysmal, shooting or stabbing pain in the greater, lesser, and/or third occipital nerve distributions. Pain intensity is often severe and debilitating, with an associated negative impact upon quality of life and function. Most cases of occipital neuralgia are idiopathic, with no clearly identifiable structural etiology. Treatment of occipital neuralgia poses inherent challenges as no criterion standard exists. Initially, conservative treatment options such as physical therapy and pharmacotherapy are routinely trialed. When occipital neuralgia is refractory to conservative measures, a number of interventional treatment options exist, including: local occipital nerve anesthetic and corticosteroid infiltration, botulinum toxin A injection, occipital nerve subcutaneous neurostimulation, and occipital nerve PRF. Of these, PRF has garnered significant interest as a potentially superior, safe, non-invasive treatment with long-term efficacy. The objective of this article is to provide a concise review of occipital neuralgia; and a concise, yet thorough, evidence-based review of the current literature concerning the use of PRF for occipital neuralgia. Review of published medical literature up through April 2013. The Center for Pain Medicine and Regional Anesthesia, the University of Iowa Hospitals and Clinics. A total of 3 clinical studies and one case report investigating the use of PRF for knee occipital neuralgia have been published worldwide. Statistically significant improvements in

  7. CT-Guided Radiofrequency Ablation of a Pulmonary Metastasis Followed by Surgical Resection

    SciTech Connect

    Steinke, Karin; Habicht, James M.; Thomsen, Sharon; Soler, Markus; Jacob, Augustinus L.

    2002-12-15

    Outpatient CT-guided radiofrequency ablation (RFA)of a pulmonary metastasis followed by surgical resection and histopathological analysis was performed in a 72-year-old lady suffering from a peritoneal leiomyosarcoma. Histological workup 3 weeks post-ablation showed complete devitalization of the metastasis. This case report demonstrates that complete thermal destruction of a pulmonary metastasis by percutaneous image-guided RFA is possible.

  8. Percutaneous fixation of scaphoid fractures.

    PubMed

    Slade, J F; Jaskwhich, D

    2001-11-01

    The scaphoid proximal pole and waist fractures presented here were treated by a novel dorsal percutaneous technique with arthroscopic assistance. All fractures healed, with good final functional results and no complications. The advantages of the dorsal percutaneous approach to scaphoid fixation are: (1) the proximal-to-distal placement of the guide pin and screw allow for more precise placement along the central axis of the scaphoid, which decreases healing time and reduces risk of screw thread exposure. (2) The dorsal approach avoids injuring the vulnerable volar ligament anatomy. And (3) the insertion of the screw from the proximal to distal direction allows the more rigid fixation of proximal scaphoid fractures. Arthroscopy allows confirmation of fracture reduction and screw implantation as well as evaluation of concurrent ligament injuries not detected with standard imaging. Percutaneous K-wires act as joysticks to reduce and compress fracture fragments prior to fixation. The presented technique allows for early, rigid internal fixation with minimal associated morbidity. Patients successfully treated with this technique include those with stable and unstable acute fractures of the scaphoid at all locations, including the proximal pole. Nondisplaced fractures that present with delayed or fibrous union without evidence of avascular necrosis, cyst formation, or bony sclerosis may also be treated with this technique. This technique allows for faster rehabilitation and an earlier return to work or avocation without restriction once CT scan confirms a solid union. Some articles document extraordinary rapid healing by standard radiographs; however, we caution that scaphoid bone healing cannot accurately be determined without CT scan. Percutaneous, arthroscopically assisted internal fixation by a dorsal approach may be considered in all acute scaphoid fractures selected for surgical fixation. The dorsal guidewire permits dorsal and volar implantation of a cannulated

  9. Diagnostic Accuracy of Post Procedural Creatine Kinase, MB Form can Predict Long-Term Outcomes in Patients Undergoing Selective Percutaneous Coronary Intervention?

    PubMed

    Maadani, Mohsen; Parchami-Ghazaee, Sepideh; Barati, Ghodratollah; Soltani, Monireh; Amiri, Elahe; Ghadrdoost, Behshid; Heidarali, Mona

    2014-02-01

    Measuring cardiac markers in blood has been the main strategy for the diagnosis of acute myocardial infarction for nearly 50 years. Creatine kinase-MB (CK-MB) has been demonstrated to be a highly specific marker. The present study aimed to assess the role of CK-MB changes following percutaneous coronary intervention (PCI) to predict one year outcomes of this procedure. This cohort study was conducted on 138 patients diagnosed with coronary artery disease who underwent PCI. Sixty-nine patients who had a CK-MB elevation ≥ 3 times upper limit of normal (ULN) post procedurally were considered as group I and 69 patients without cardiac enzyme rise after PCI were considered as the control group (group II). The composite end point of major adverse cardiac events (MACE) during one year was assessed by telephone follow-up or presentation at clinical visiting, and compared between the two groups. The MACE was defined as the appearance of at least one of the following events: mortality, repeated revascularization procedures, myocardial infarction, or cerebrovascular events. Although one year mortality in the group I was 4 (5.8%), about two times greater than the other group 2 (2.9%), the difference was not significantly discrepant (P = 0.57). Moreover, 8 (11.6%) of patients in group I experienced one year MACE, while this rate in the other group was 4 (5.8%), with insignificant difference (P = 0.22). In group I, one case experienced coronary artery bypass surgery, one, exhibited cerebrovascular disease and one reported ST segment elevation myocardial infarction (STEMI), while two patients in the other group were suspicious of having non-ST segment elevation myocardial infarction (NSTEMI) and candidates for repeated PCI. Multivariate analysis revealed that increased post-procedural CK-MB ≥ 3 times UNL could not predict long-term MACE in patients who underwent selective PCI. Area under the curve (AUC) for predicting one year MACE was 0.593 (95% CI: 0.397 - 0

  10. Fraxelated radiofrequency device for acne scars

    NASA Astrophysics Data System (ADS)

    Rao, Babar K.; Khokher, Sairah

    2012-09-01

    Acne scars can be improved with various treatments such as topical creams, chemical peels, dermal fillers, microdermabrasion, laser, and radiofrequency devices. Some of these treatments especially lasers and deep chemical peels can have significant side effects such as post inflammatory hyperpigmentation in darker skin types. Fraxelated RF Laser devices have been reported to have lower incidence of side effects in all skin phototypes. Nine patients between ages 18 and 35 of various skin phototypes were selected from a private practice and treated with a RF fraxelated device (E-matrix) for acne scars. Outcomes were measured by physician observation, subjective feedback received by patients, and comparison of before and after photographs. In this small group of patients with various skin phototypes, fraxelated radiofrequency device improved acne scars with minimal side effects and downtime.

  11. Pulmonary radiofrequency ablation (Part 1): current state.

    PubMed

    Plasencia Martínez, J M

    2015-01-01

    The risks involved in surgical treatment and conventional radiotherapy in patients with early lung cancer or lung metastases often make these treatments difficult to justify. However, on the other hand, it is also unacceptable to allow these lesions to evolve freely because, left untreated, these neoplasms will usually lead to the death of the patient. In recent years, alternative local therapies have been developed, such as pulmonary radiofrequency ablation, which has proven to increase survival with a minimal risk of complications. There are common recommendations for these treatments, and although the specific indications for using one technique or another have yet to be established, there are clearly defined situations that will determine the outcome of the treatment. It is important to know these situations, because appropriate patient selection is essential for therapeutic success. This article aims to describe the characteristics and constraints of pulmonary radiofrequency ablation and to outline its role in thoracic oncology in light of the current evidence.

  12. Percutaneous image-guided ablation of breast tumors: an overview.

    PubMed

    Sag, Alan A; Maybody, Majid; Comstock, Christopher; Solomon, Stephen B

    2014-06-01

    Percutaneous non-surgical image-guided ablation is emerging as an adjunct or alternative to surgery in the management of benign and malignant breast tumors. This review covers the current state of the literature regarding percutaneous image-guided ablation modalities, clinical factors regarding patient selection, and future directions for research.

  13. Percutaneous Image-Guided Ablation of Breast Tumors: An Overview

    PubMed Central

    Sag, Alan A.; Maybody, Majid; Comstock, Christopher; Solomon, Stephen B.

    2014-01-01

    Percutaneous non-surgical image-guided ablation is emerging as an adjunct or alternative to surgery in the management of benign and malignant breast tumors. This review covers the current state of the literature regarding percutaneous image-guided ablation modalities, clinical factors regarding patient selection, and future directions for research. PMID:25049447

  14. A standardized way to select, evaluate, and test an analog-to-digital converter for ultrawide bandwidth radiofrequency signals based on user's needs, ideal, published,and actual specifications

    NASA Astrophysics Data System (ADS)

    Chang, Daniel Y.; Rowe, Neil C.

    2012-06-01

    The most important adverse impact on the Electronic Warfare (EW) simulation is that the number of signal sources that can be tested simultaneously is relatively small. When the number of signal sources increases, the analog hardware, complexity and costs grow by the order of N2, since the number of connections among N components is O(N*N) and the signal communication is bi-directional. To solve this problem, digitization of the signal is suggested. In digitizing a radiofrequency signal, an Analog-to-Digital Converter (ADC) is widely used. Most research studies on ADCs are conducted from designer/test engineers' perspective. Some research studies are conducted from market's perspective. This paper presents a generic way to select, evaluate and test ultra high bandwidth COTS ADCs and generate requirements for digitizing continuous time signals from the perspective of user's needs. Based on user's needs, as well as vendor's published, ideal and actual specifications, a decision can be made in selecting a proper ADC for an application. To support our arguments and illustrate the methodology, we evaluate a Tektronix TADC-1000, an 8-bit and 12 gigasamples per second ADC. This project is funded by JEWEL lab, NAWCWD at Point Mugu, CA.

  15. Major complications after radiofrequency ablation for liver tumors: Analysis of 255 patients

    PubMed Central

    Kong, Wen-Tao; Zhang, Wei-Wei; Qiu, Yu-Dong; Zhou, Tie; Qiu, Jun-Lan; Zhang, Wei; Ding, Yi-Tao

    2009-01-01

    AIM: To investigate the major complications after radiofrequency ablation (RFA) for the treatment of liver tumors and analyze possible risk factors that precipitate these complications. METHODS: From March 2001 to April 2008, 255 patients with liver tumors (205 male, 50 female; age range, 18-89 years; mean age, 56.0 years) who received RFA were enrolled in this study. Of these patients, 212 had hepatocellular carcinoma, 39 had metastatic liver tumors and four had cholangiocellular carcinoma. One hundred and forty eight patients had a single tumor, and 107 had multiple tumors. Maximum diameter of the tumors ranged 1.3-20 cm (mean, 5.1 cm). All patients were treated with a cooled-tip perfusion electrode attached to a radiofrequency generator (Radionics, Burlington, MA, USA). RFA was performed via the percutaneous approach (n = 257), laparoscopy (n = 7), or open surgical treatment (n = 86). The major complications related to RFA were recorded. The resultant data were analyzed to determine risk factors associated these complications. RESULTS: Among the 255 patients, 425 liver tumors were treated and 350 RFA sessions were performed. Thirty-seven (10%) major complications were observed which included 13 cases of liver failure, 10 cases of hydrothorax requiring drainage, three cases of tumor seeding, one case of upper gastrointestinal bleeding, one case of intrahepatic abscess, one case of bile duct injury, one case of cardiac arrest, and five cases of hyperglycemia. Seven patients had more than two complications. Liver failure was the most severe complication and was associated with the highest mortality. Eleven patients died due to worsening liver decompensation. Child-Pugh classification (P = 0.001) and choice of approach (P = 0.045) were related to post-treatment liver failure, whereas patient age, tumor size and number were not significant factors precipitating this complication. CONCLUSION: RFA can be accepted as a relatively safe procedure for the treatment of

  16. Major complications after radiofrequency ablation for liver tumors: analysis of 255 patients.

    PubMed

    Kong, Wen-Tao; Zhang, Wei-Wei; Qiu, Yu-Dong; Zhou, Tie; Qiu, Jun-Lan; Zhang, Wei; Ding, Yi-Tao

    2009-06-07

    To investigate the major complications after radiofrequency ablation (RFA) for the treatment of liver tumors and analyze possible risk factors that precipitate these complications. From March 2001 to April 2008, 255 patients with liver tumors (205 male, 50 female; age range, 18-89 years; mean age, 56.0 years) who received RFA were enrolled in this study. Of these patients, 212 had hepatocellular carcinoma, 39 had metastatic liver tumors and four had cholangiocellular carcinoma. One hundred and forty eight patients had a single tumor, and 107 had multiple tumors. Maximum diameter of the tumors ranged 1.3-20 cm (mean, 5.1 cm). All patients were treated with a cooled-tip perfusion electrode attached to a radiofrequency generator (Radionics, Burlington, MA, USA). RFA was performed via the percutaneous approach (n = 257), laparoscopy (n = 7), or open surgical treatment (n = 86). The major complications related to RFA were recorded. The resultant data were analyzed to determine risk factors associated these complications. Among the 255 patients, 425 liver tumors were treated and 350 RFA sessions were performed. Thirty-seven (10%) major complications were observed which included 13 cases of liver failure, 10 cases of hydrothorax requiring drainage, three cases of tumor seeding, one case of upper gastrointestinal bleeding, one case of intrahepatic abscess, one case of bile duct injury, one case of cardiac arrest, and five cases of hyperglycemia. Seven patients had more than two complications. Liver failure was the most severe complication and was associated with the highest mortality. Eleven patients died due to worsening liver decompensation. Child-Pugh classification (P = 0.001) and choice of approach (P = 0.045) were related to post-treatment liver failure, whereas patient age, tumor size and number were not significant factors precipitating this complication. RFA can be accepted as a relatively safe procedure for the treatment of liver tumors. However, attention should

  17. Percutaneous Nephroscopic Surgery

    PubMed Central

    2010-01-01

    With the development of techniques for percutaneous access and equipment to disintegrate calculi, percutaneous nephroscopic surgery is currently used by many urologists and is the procedure of choice for the removal of large renal calculi and the management of diverticula, intrarenal strictures, and urothelial cancer. Although it is more invasive than shock wave lithotripsy and retrograde ureteroscopic surgery, percutaneous nephroscopic surgery has been successfully performed with high efficiency and low morbidity in difficult renal anatomies and patient conditions. These advantages of minimal invasiveness were rapidly perceived and applied to the management of ureteropelvic junction obstruction, calyceal diverticulum, infundibular stenosis, and urothelial cancer. The basic principle of endopyelotomy is a full-thickness incision of the narrow segment followed by prolonged stenting and drainage to allow regeneration of an adequate caliber ureter. The preferred technique for a calyceal diverticulum continues to be debated. Excellent long-term success has been reported with percutaneous, ureteroscopic, and laparoscopic techniques. Each approach is based on the location and size of the diverticulum. So far, percutaneous ablation of the calyceal diverticulum is the most established minimally invasive technique. Infundibular stenosis is an acquired condition usually associated with inflammation or stones. Reported series of percutaneously treated infundibular stenosis are few. In contrast with a calyceal diverticulum, infundibular stenosis is a more difficult entity to treat with only a 50-76% success rate by percutaneous techniques. Currently, percutaneous nephroscopic resection of transitional cell carcinoma in the renal calyx can be applied in indicated cases. PMID:20495691

  18. Percutaneous Biopsy of Osteoid Osteomas Prior to Percutaneous Treatment Using Two Different Biopsy Needles

    SciTech Connect

    Laredo, Jean-Denis Hamze, Bassam; Jeribi, Riadh

    2009-09-15

    Biopsy is usually performed as the first step in percutaneous treatment of osteoid osteomas prior to laser photocoagulation. At our institution, 117 patients with a presumed diagnosis of osteoid osteoma had a trephine biopsy before a percutaneous laser photocoagulation. Biopsies were made using two different types of needles. A Bonopty biopsy needle (14-gauge cannula, 16-gauge trephine needle; Radi Medical Systems, Uppsala, Sweden) was used in 65 patients, and a Laurane biopsy needle (11-gauge cannula, 12.5-gauge trephine needle; Laurane Medical, Saint-Arnoult, France) in 43 patients. Overall biopsy results were positive for osteoid osteoma in 83 (70.9%) of the 117 cases. The Laurane needle provided a significantly higher positive rate (81.4%) than the Bonopty needle (66.1%; p < 0.05). This difference was not due to the size of the nidus, which was similar in the two groups (p < 0.05) and may be an effect of differences in needle caliber (12.5 vs. 14 gauge) as well as differences in needle design. The rate of positive biopsy results obtained in the present series with the Laurane biopsy needle is, to our knowledge, the highest rate reported in series dealing with percutaneous radiofrequency ablation and laser photocoagulation of osteoid osteomas.

  19. Percutaneous forefoot surgery.

    PubMed

    Bauer, T

    2014-02-01

    Percutaneous methods can be used to perform many surgical procedures on the soft tissues and bones of the forefoot, thereby providing treatment options for all the disorders and deformities seen at this site. Theoretical advantages of percutaneous surgery include lower morbidity rates and faster recovery with immediate weight bearing. Disadvantages are the requirement for specific equipment, specific requirements for post-operative management, and lengthy learning curve. At present, percutaneous hallux valgus correction is mainly achieved with chevron osteotomy of the first metatarsal, for which internal fixation and a minimally invasive approach (2 cm incision) seem reliable and reproducible. This procedure is currently the focus of research and evaluation. Percutaneous surgery for hallux rigidus is simple and provides similar outcomes to those of open surgery. Lateral metatarsal malalignment and toe deformities are good indications for percutaneous treatment, which produces results similar to those of conventional surgery with lower morbidity rates. Finally, fifth ray abnormalities are currently the ideal indication for percutaneous surgery, given the simplicity of the procedure and post-operative course, high reliability, and very low rate of iatrogenic complications. The most commonly performed percutaneous techniques are described herein, with their current indications, main outcomes, and recent developments.

  20. Current oncologic applications of radiofrequency ablation therapies

    PubMed Central

    Shah, Dhruvil R; Green, Sari; Elliot, Angelina; McGahan, John P; Khatri, Vijay P

    2013-01-01

    Radiofrequency ablation (RFA) uses high frequency alternating current to heat a volume of tissue around a needle electrode to induce focal coagulative necrosis with minimal injury to surrounding tissues. RFA can be performed via an open, laparoscopic, or image guided percutaneous approach and be performed under general or local anesthesia. Advances in delivery mechanisms, electrode designs, and higher power generators have increased the maximum volume that can be ablated, while maximizing oncological outcomes. In general, RFA is used to control local tumor growth, prevent recurrence, palliate symptoms, and improve survival in a subset of patients that are not candidates for surgical resection. It’s equivalence to surgical resection has yet to be proven in large randomized control trials. Currently, the use of RFA has been well described as a primary or adjuvant treatment modality of limited but unresectable hepatocellular carcinoma, liver metastasis, especially colorectal cancer metastases, primary lung tumors, renal cell carcinoma, boney metastasis and osteoid osteomas. The role of RFA in the primary treatment of early stage breast cancer is still evolving. This review will discuss the general features of RFA and outline its role in commonly encountered solid tumors. PMID:23671734

  1. Radiofrequency attenuator and method

    DOEpatents

    Warner, Benjamin P.; McCleskey, T. Mark; Burrell, Anthony K.; Agrawal, Anoop; Hall, Simon B.

    2009-11-10

    Radiofrequency attenuator and method. The attenuator includes a pair of transparent windows. A chamber between the windows is filled with molten salt. Preferred molten salts include quarternary ammonium cations and fluorine-containing anions such as tetrafluoroborate (BF.sub.4.sup.-), hexafluorophosphate (PF.sub.6.sup.-), hexafluoroarsenate (AsF.sub.6.sup.-), trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3 C.sup.-). Radicals or radical cations may be added to or electrochemically generated in the molten salt to enhance the RF attenuation.

  2. Radiofrequency attenuator and method

    DOEpatents

    Warner, Benjamin P [Los Alamos, NM; McCleskey, T Mark [Los Alamos, NM; Burrell, Anthony K [Los Alamos, NM; Agrawal, Anoop [Tucson, AZ; Hall, Simon B [Palmerston North, NZ

    2009-01-20

    Radiofrequency attenuator and method. The attenuator includes a pair of transparent windows. A chamber between the windows is filled with molten salt. Preferred molten salts include quarternary ammonium cations and fluorine-containing anions such as tetrafluoroborate (BF.sub.4.sup.-), hexafluorophosphate (PF.sub.6.sup.-), hexafluoroarsenate (AsF.sub.6.sup.-), trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3C.sup.-). Radicals or radical cations may be added to or electrochemically generated in the molten salt to enhance the RF attenuation.

  3. Radiofrequency Ablation of Lung Tumors

    MedlinePlus

    ... you may need to be admitted overnight for observation. What are Radiofrequency and Microwave Ablation of Lung ... performed on an outpatient basis or with overnight observation in the hospital with general anesthesia. For the ...

  4. [Treatment of atherosclerosis. New percutaneous intraluminal techniques].

    PubMed

    Lablanche, J M

    1990-10-06

    Balloon-catheter angioplasty was introduced by Gruntzig in 1977 and has since proved effective, but 3 problems are still encountered: immediate reobstruction, restenosis during the first 3 months and extension of the procedure to a greater number of cases. In an attempt to solve these problems, other percutaneous/technics, associated or not with balloon angioplasty, have been devised. They are: (1) intraluminal stents which perfectly keep the vessel open after balloon angioplasty; (2) vaporization of atheromatous plaques by laser, and notably excimer laser which results in immediate recanalization, later completed by balloon angioplasty; (3) heating balloons which stick dissections and improve the immediate success rate; (4) atheroma-cutting and storing systems, such as Simpson's atherocath, cutting and aspirating systems, such as Stack's transluminal extraction catheter, or erasing systems, such as Auth's rotablator; (5) other sources of energy, such as ultrasounds, microwaves and radiofrequencies, will perhaps, be used in the near future. None of these new technics has solved the restenosis problem, but all have proved effective in suppressing the obstacle, there by giving hopes of reducing immediate complications and gradually widening the indications of percutaneous revascularization.

  5. Percutaneous angioscopy. Work in progress.

    PubMed

    Ferris, E J; Ledor, K; ben-Avi, D D; Baker, M L; Robbins, K V; McCowan, T C; Sharma, B

    1985-11-01

    The cardiovascular applications of flexible fiber-optic technology are imminent because of recent advances in miniaturization. In the work described here, angioscopy, or vascular endoscopy, was performed in the cadaveric aorta and in the systemic and pulmonary circulations of the canine model and selected human patients. Subsequent to our development of percutaneous techniques, clinical trials have ranged from lower-extremity venoscopy to aortic-root arterioscopy. Angioscopy could be clinically useful because of relative or absolute contraindications to iodinated contrast material. The ability to see in color and three dimensions may afford some other advantages to angioscopy over conventional angiography.

  6. Percutaneous Posterior Calcaneal Osteotomy.

    PubMed

    Lui, Tun Hing

    2015-01-01

    Different types of posterior calcaneal osteotomy are used for calcaneal realignment in the management of hindfoot deformity. We describe a percutaneous technique of posterior calcaneal osteotomy that can be either a Dwyer-type closing wedge osteotomy or displacement osteotomy.

  7. Radiofrequency Ablation to Prevent Sudden Cardiac Death.

    PubMed

    Atoui, Moustapha; Gunda, Sampath; Lakkireddy, Dhanunjaya; Mahapatra, Srijoy

    2015-01-01

    Radiofrequency ablation may prevent or treat atrial and ventricular arrhythmias. Since some of these arrhythmias are associated with sudden cardiac death, it has been hypothesized that ablation may prevent sudden death in certain cases. We performed a literature search to better understand under which circumstances ablation may prevent sudden death and found little randomized data demonstrating the long-term effects of ablation. Current literature shows that ablation clearly prevents symptoms of arrhythmia and may reduce the incidence of sudden cardiac death in select patients, although data does not indicate improved mortality. Ongoing clinical trials are needed to better define the role of ablation in preventing sudden cardiac death.

  8. Radiofrequency for the treatment of skin laxity: mith or truth*

    PubMed Central

    de Araújo, Angélica Rodrigues; Soares, Viviane Pinheiro Campos; da Silva, Fernanda Souza; Moreira, Tatiane da Silva

    2015-01-01

    The nonablative radiofrequency is a procedure commonly used for the treatment of skin laxity from an increase in tissue temperature. The goal is to induce thermal damage to thus stimulate neocollagenesis in deep layers of the skin and subcutaneous tissue. However, many of these devices haven't been tested and their parameters are still not accepted by the scientific community. Because of this, it is necessary to review the literature regarding the physiological effects and parameters for application of radiofrequency and methodological quality and level of evidence of studies. A literature search was performed in MEDLINE, PEDro, SciELO, PubMed, LILACS and CAPES and experimental studies in humans, which used radiofrequency devices as treatment for facial or body laxity, were selected. The results showed that the main physiological effect is to stimulate collagen synthesis. There was no homogeneity between studies in relation to most of the parameters used and the methodological quality of studies and level of evidence for using radiofrequency are low. This fact complicates the determination of effective parameters for clinical use of this device in the treatment of skin laxity. The analyzed studies suggest that radiofrequency is effective, however the physiological mechanisms and the required parameters are not clear in the literature. PMID:26560216

  9. Combination acetabular radiofrequency ablation and cementoplasty using a navigational radiofrequency ablation device and ultrahigh viscosity cement: technical note.

    PubMed

    Wallace, Adam N; Huang, Ambrose J; Vaswani, Devin; Chang, Randy O; Jennings, Jack W

    2016-03-01

    Percutaneous radiofrequency ablation and cementoplasty is an alternative palliative therapy for painful metastases involving axial load-bearing bones. This technical report describes the use of a navigational radiofrequency probe to ablate acetabular metastases from an anterior approach followed by instillation of ultrahigh viscosity cement under CT-fluoroscopic guidance. The tumor ablation databases of two institutions were retrospectively reviewed to identify patients who underwent combination acetabular radiofrequency ablation and cementoplasty using the STAR Tumor Ablation and StabiliT Vertebral Augmentation Systems (DFINE; San Jose, CA). Pre-procedure acetabular tumor volume was measured on cross-sectional imaging. Pre- and post-procedure pain scores were measured using the Numeric Rating Scale (10-point scale) and compared. Partial pain improvement was categorically defined as ≥ 2-point pain score reduction. Patients were evaluated for evidence of immediate complications. Electronic medical records were reviewed for evidence of delayed complications. During the study period, 12 patients with acetabular metastases were treated. The median tumor volume was 54.3 mL (range, 28.3-109.8 mL). Pre- and post-procedure pain scores were obtained from 92% (11/12) of the cohort. The median pre-procedure pain score was 8 (range, 3-10). Post-procedure pain scores were obtained 7 days (82%; 9/11), 11 days (9.1%; 1/11) or 21 days (9.1%; 1/11) after treatment. The median post-treatment pain score was 3 (range, 1-8), a statistically significant difference compared with pre-treatment (P = 0.002). Categorically, 73% (8/11) of patients reported partial pain relief after treatment. No immediate symptomatic complications occurred. Three patients (25%; 3/12) were discharged to hospice within 1 week of treatment. No delayed complications occurred in the remaining 75% (9/12) of patients during median clinical follow-up of 62 days (range, 14-178 days). Palliative percutaneous

  10. Measurement of radiofrequency fields

    SciTech Connect

    Leonowich, J.A.

    1992-05-01

    We are literally surrounded by radiofrequency (RFR) and microwave radiation, from both natural and man-made sources. The identification and control of man-made sources of RFR has become a high priority of radiation safety professionals in recent years. For the purposes of this paper, we will consider RFR to cover the frequencies from 3 kHz to 300 MHz, and microwaves from 300 MHz to 300 GHz, and will use the term RFR interchangeably to describe both. Electromagnetic radiation and field below 3 kHz is considered Extremely Low Frequency (ELF) and will not be discussed in this paper. Unlike x- and gamma radiation, RFR is non-ionizing. The energy of any RFR photon is insufficient to produce ionizations in matter. The measurement and control of RFR hazards is therefore fundamentally different from ionizing radiation. The purpose of this paper is to acquaint the reader with the fundamental issues involved in measuring and safely using RFR fields. 23 refs.

  11. Light modulated electron beam driven radiofrequency emitter

    DOEpatents

    Wilson, M.T.; Tallerico, P.J.

    1979-10-10

    The disclosure relates to a light modulated electron beam-driven radiofrequency emitter. Pulses of light impinge on a photoemissive device which generates an electron beam having the pulse characteristics of the light. The electron beam is accelerated through a radiofrequency resonator which produces radiofrequency emission in accordance with the electron, hence, the light pulses.

  12. Saline Infusion Markedly Reduces Impedance and Improves Efficacy of Pulmonary Radiofrequency Ablation

    SciTech Connect

    Gananadha, Sivakumar Morris, David Lawson

    2004-08-15

    Radiofrequency ablation (RFA) is a relatively new technique that has been investigated for the treatment of lung tumors. We evaluated for the first time the in vivo use of saline infusion during radiofrequency ablation of sheep lung. We performed RFA on 5 sheep using open and closed chest RFA and the RITA starburst XL and Xli probes using saline infusion with the Xli probe. The impedance and volume of ablation were compared. A total of 16 ablations were produced, 5 percutaneously and 11 open. The impedance during percutaneous and open RFA without saline infusion was 110 {+-} 16.2 and 183.3 {+-} 105.8 O, respectively. With the saline infusion the impedance was 71.3 {+-} 22O and 103.6 {+-} 37.5O. The effect of this was a significantly larger volume of ablation using the saline infusion during percutaneous RFA (90.6 {+-} 23 cm{sup 3} vs 10.47 {+-} 2.9 cm{sup 3}, p = 0.01) and open RFA (107.8 {+-} 25.8 cm{sup 3} vs 24.9 {+-} 19.3 cm{sup 3}, p = 0.0002). Saline infusion during RFA is associated with lower impedance, higher power delivery and larger lesion size.

  13. Radiofrequency fields and teratogenesis.

    PubMed

    Heynick, Louis N; Merritt, James H

    2003-01-01

    Experimental studies that sought teratologic effects or developmental abnormalities from exposure to radiofrequency electromagnetic fields (RFEMF) in the range 3 kHz-300 GHz are critically reviewed for their possible consequences on human health. Those studies were conducted on beetles, birds, rodents, and nonhuman primates. Collectively, those experimental studies indicate that teratologic effects can occur only from exposure levels that cause biologically detrimental increases in body temperature. No reliable experimental evidence was found for nonthermal teratologic effects; rodents, mouse fetuses, and perinatal mice are more susceptible to such effects than rats. The primary confirmed effect in rats at high RFEMF levels was initial weight deficits in fetuses and neonates that decreased with infant growth. More generally from findings with pregnant mammals, exposures at RFEMF levels far higher than those permitted under the IEEE human exposure guidelines are necessary to reach or exceed cited experimental thresholds for maternal temperature increases. Some results indicated that the levels necessary to cause such effects in pregnant mammals could exceed those lethal to the dams. In a behavioral study of squirrel monkeys, no effects were observed on usual dam-offspring interactions or EEGs, but unexpected deaths of a number of offspring had occurred. However, this finding was not confirmed in a study solely on infant death using a larger number of subjects for greater statistical validity. Also reviewed were epidemiologic studies of various human populations considered to have been chronically exposed to environmental levels of RFEMF. Early studies on the incidence of congenital anomalies yielded no credible evidence that chronic exposure of pregnant women or of fathers exposed to RFEMF from nearby sources at levels below those guidelines would cause any anomalies in their offspring. The findings of studies on pregnancy outcomes of female physiotherapists

  14. Radiofrequency Ablation of Hepatocellular Carcinoma: A Literature Review

    PubMed Central

    Minami, Yasunori; Kudo, Masatoshi

    2011-01-01

    Radiofrequency ablation (RFA) of liver cancers can be performed safely using percutaneous, laparoscopic, or open surgical techniques, and much of the impetus for the use of RFA has come from cohort series that have provided an evidence base for this technique. Here, we give an overview of the current status of radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC), including its physical properties, to assess the characteristics that make this technique applicable in clinical practice. We review the technical development of probe design and summarize current indications and outcomes of reported clinical use. An accurate evaluation of treatment response is very important to secure successful RFA therapy since a sufficient safety margin (at least 0.5 cm) can prevent local tumor recurrences. We also provide a profile of side effects and information on the integration of this technique into the general management of patients with HCC. To minimize complications of RFA, physicians should be familiar with each feature of complication. Appropriate management of complications is essential for successful RFA treatment. Moreover, adjuvant therapy, such as molecular targeted therapies following curative therapy, is expected to further improve survival after RFA. PMID:21994847

  15. Percutaneous destructive pain procedures on the upper spinal cord and brain stem in cancer pain: CT-guided techniques, indications and results.

    PubMed

    Kanpolat, Y

    2007-01-01

    In the century of science and technology, the average life span has increased, bringing with it an increase in the incidence of degenerative and cancer disease. Intractable pain is usually the main symptom of cancer. With the advancement in technology, there is a large group of patients with intractable pain problems who can benefit from special help medically or surgically. Destructive pain procedures are necessary to control the cancer pain and are based on the lesioning of the pain conducting pathways. Percutaneous cordotomy, trigeminal tractotomy and extralemniscal myelotomy are special methods based on lesioning of the pain conducting pathways. The procedure consists of obtaining direct morphological appearance of the upper spinal cord and surrounding structures by computed tomography (CT). The next step is functional evaluation of the target and its environment by impedance measurement and stimulation. The final step is terminated with controlled lesioning obtained by a radiofrequency system (generator, needles, electrode system). In the last two decades, CT-guided destructive procedures were used as minimally invasive procedures as follows: percutaneous cordotomy (207 patients), trigeminal tractotomy-nucleotomy (65 patients), and extralemniscal myelotomy (16 patients). Most of these patients had cancer pain. Minimally invasive CT-guided destructive pain procedures are still safe and effective operations for relieving intractable cancer pain in selected cases.

  16. a Radio-Frequency

    NASA Astrophysics Data System (ADS)

    Foo, Thomas Kwok-Fah

    Radio-frequency (RF) inhomogeneity encountered in magnetic resonance (MR) imaging poses a significant impediment to obtaining images of the highest diagnostic quality. This inhomogeneity arises from the conductivity effect, which attenuates the RF field with increasing depth, and the permittivity effect. The latter is the dominant effect at 1.5 Tesla (64 MHz), and contributes to standing waves within the body. A theoretical model has been developed which describes these effects for an infinitely long right circularly cylindrical object inside a concentric RF coil and RF shield. This model assumes that the RF field propagates as a travelling wave in the z direction, along the long axis of the cylinder. The resulting solutions adequately predict the field distribution for RF coils which have both a finite wavelength and an infinite wavelength in z. This corresponds to high-pass and low-pass birdcage resonators, respectively, that are in general used in MR imaging. Standing wave models are easily obtained from the superposition of solutions of two travelling waves in opposite directions. The results of this model indicate that the axial propagation constant k_{z} is a strong function of the dielectric present in the coil -to-shield space. The field distribution in the axial plane can be represented by the Bessel function J_1(k _{rho}r), where k _sp{rho}{2} = k^2-k_sp{z}{2} . By varying the dielectric material occupying the coil-to-shield space, an optimum value of k _{z} can be obtained for a particular coil and shield configuration which minimizes the amplitude variations in the axial plane. Experimental verification of the theoretical model has been obtained. These measurements were performed on a non-resonant, travelling wave test coil with a saline phantom as a load simulating the body. The measured field profiles in the axial plane agree with the predicted values, establishing the validity of the theoretical model. As expected, optimal RF homogeneity was obtained

  17. The effect of volatility on percutaneous absorption.

    PubMed

    Rouse, Nicole C; Maibach, Howard I

    2016-01-01

    Topically applied chemicals may volatilize, or evaporate, from skin leaving behind a chemical residue with new percutaneous absorptive capabilities. Understanding volatilization of topical medications, such as sunscreens, fragrances, insect repellants, cosmetics and other commonly applied topicals may have implications for their safety and efficacy. A systematic review of English language articles from 1979 to 2014 was performed using key search terms. Articles were evaluated to assess the relationship between volatility and percutaneous absorption. A total of 12 articles were selected and reviewed. Key findings were that absorption is enhanced when coupled with a volatile substance, occlusion prevents evaporation and increases absorption, high ventilation increases volatilization and reduces absorption, and pH of skin has an affect on a chemical's volatility. The articles also brought to light that different methods may have an affect on volatility: different body regions; in vivo vs. in vitro; human vs. Data suggest that volatility is crucial for determining safety and efficacy of cutaneous exposures and therapies. Few articles have been documented reporting evaporation in the context of percutaneous absorption, and of those published, great variability exists in methods. Further investigation of volatility is needed to properly evaluate its role in percutaneous absorption.

  18. Heat distribution and heat transport in bone during radiofrequency catheter ablation.

    PubMed

    Rachbauer, F; Mangat, J; Bodner, G; Eichberger, P; Krismer, M

    2003-04-01

    To assess the feasibility of percutaneous radiofrequency ablation in large bone tumours, the heat distribution in cortical bone and marrow around inserted electrodes was measured. Fresh bovine cadaver tibial bones were locally heated through drill holes for a maximum of half an hour using water-cooled single radiofrequency electrodes (Radionics Instruments Inc) by pulsed energy. Temperatures were measured in the marrow canal as well as in cortical bone by thermocouples at various distances from the inserted probes. Perpendicular to the probe, hyperthermia of more than 50 degrees C could be created in bone marrow in a sphere of approximately 3 cm, and of approximately 1 cm in cortical bone. As irreversible cellular damage can be expected when increasing the temperature to 50 degrees C for a duration of 6 min, this method may be effective for the minimal invasive ablation of neoplasms within human bone in cigar-shaped regions of approximately 3-cm diameter.

  19. Percutaneous Abscess Drainage

    MedlinePlus

    ... the local anesthetic is injected. Most of the sensation is at the skin incision site which is numbed using local anesthetic. ... open surgical drainage. Risks Any procedure where the skin is penetrated ... organ may be damaged by percutaneous abscess drainage. Occasionally ...

  20. Role of paravertebral block anaesthesia during percutaneous transhepatic thermoablation.

    PubMed

    Gazzera, Carlo; Fonio, Paolo; Faletti, Riccardo; Dotto, Maria Chiara; Gobbi, Fabio; Donadio, Pierpaolo; Gandini, Giovanni

    2014-08-01

    This paper discusses the technique and preliminary results of right thoracic paravertebral block (TPVB) for percutaneous thermal ablation of liver tumours. Between October 2011 and August 2012 we treated 36 lesions (25 hepatocellular carcinoma and 11 metastases) in 30 patients aged 47-85 years (mean 67.5). Patients received ultrasound (US)-guided injection of 7 ml of naropin 0.75 % in T7, T9 and T11 levels, below the costo-vertebral ligament, until we observed an anterior displacement of the parietal pleura. For the subcapsular lesions, a cervical right phrenic nerve block was associated. The level of analgesia was evaluated during and after the percutaneous procedures with the Numerical Rating Scale. Finally, we investigated statistical correlations between pain and lesions (histological type, site, dimensions), and ablation time and technique (microwave or radiofrequency ablation). Technical success was achieved in all patients. Despite the correct anaesthetic diffusion during the ablation, 10 patients (33.3 %) reported medium/severe pain and intravenous sedation was required. Pain was not found to correlate with any variable. No complications were observed. In most cases, TPVB is a safe and effective technique for conscious anaesthesia during percutaneous thermal ablation of liver tumours. Failures probably derive from left sympathetic and parasympathetic fibre stimulation. We recommend performing a TPVB in the presence of the anaesthetist.

  1. Image-guided minimally invasive percutaneous treatment of spinal metastasis

    PubMed Central

    Yang, Ping-Lin; He, Xi-Jing; Li, Hao-Peng; Zang, Quan-Jin; Wang, Guo-Yu

    2017-01-01

    In order to provide effective options for minimally invasive treatment of spinal metastases, the present study retrospectively evaluated the efficacy and safety of image-guided minimally invasive percutaneous treatment of spinal metastases. Image-guided percutaneous vertebral body enhancement, radiofrequency ablation (RFA) and tumor debulking combined with other methods to strengthen the vertebrae were applied dependent on the indications. Percutaneous vertebroplasty (PVP) was used when vertebral body destruction was simple. In addition, RFA was used in cases where pure spinal epidural soft tissue mass or accessories (spinous process, vertebral plate and vertebral pedicle) were destroyed, but vertebral integrity and stability existed. Tumor debulking (also known as limited RFA) combined with vertebral augmentation were used in cases presenting destruction of the epidural soft tissue mass and accessories, and pathological vertebral fractures. A comprehensive assessment was performed through a standardized questionnaire and indicators including biomechanical stability of the spine, quality of life, neurological status and tumor progression status were assessed during the 6 weeks-6 months follow-up following surgery. After the most suitable treatment was used, the biomechanical stability of the spine was increased, the pain caused by spinal metastases within 6 weeks was significantly reduced, while the daily activities and quality of life were improved. The mean progression-free survival of tumors was 330±54 days, and no associated complications occurred. Therefore, the use of a combination of image-guided PVP, RFA and other methods is safe and effective for the treatment of spinal metastases. PMID:28352355

  2. Long-term bioeffects of 435-MHz radiofrequency radiation on selected blood-borne endpoints in cannulated rats. Volume 2. Plasma ACTH (adrenocorticotropic hormone) and plasma corticosterone. Final report, 20 August 1984-16 February 1986

    SciTech Connect

    Popovic, V.P.; Toler, J.C.; Bonasera, S.J.; Popovic, P.P.; Honeycutt, C.B.

    1987-08-01

    Two hundred adult male white rats with chronically implanted aortic cannulas were randomly divided into two groups. Animals in the first group were exposed to low-level (1.0 mW/cm2) pulsed-wave 435-MHz radiofrequency radiation (RFR) for approximately 22 h daily, 7 days each week, for 6 months. Animals in the second group were maintained under identical conditions, but were not radiated. The cannulas were used to draw microsamples (0.3 mL) of aortic blood from the unrestrained, unanesthetized rats on a cyclic schedule. Plasma adrenocorticotropic hormone (ACTH) and plasma corticosterone concentrations were determined by radioimmunoassays hormone (ACTH) and plasma corticosterone concentrations were determined by radioimmunoassays. Statistical analysis of the results did not indicate increased plasma ACTH and plasma corticosterone concentrations in exposed animals when compared to sham-exposed animals. Exposure to this low-level radiofrequency environment did not induce stresses that were manifested as an alteration in plasma hormones.

  3. [Contrast-enhanced sonography. Therapy control of radiofrequency ablation and transarterial chemoembolization of hepatocellular carcinoma].

    PubMed

    Jung, E M; Uller, W; Stroszczynski, C; Clevert, D-A

    2011-06-01

    Due to the imaging of dynamic perfusion, hepatocellular carcinoma can be detected with a sensitivity of >90% using contrast-enhanced sonography. The characterization of liver tumors with contrast-enhanced sonography is comparable to the diagnostic accuracy of contrast-enhanced computed tomography. The dynamic detection of microvascularization with contrast-enhanced sonography allows the differentiation between vascularized tumors and non-vascularized necrotic lesions before, during and after transarterial chemoembolization or percutaneous radiofrequency ablation. Image fusion with volume navigation can be useful in the followup control.

  4. Spontaneous Regression of Multiple Pulmonary Metastases After Radiofrequency Ablation of a Single Metastasis

    SciTech Connect

    Rao, Pramod; Escudier, Bernard; Baere, Thierry de

    2011-04-15

    We report two cases of spontaneous regression of multiple pulmonary metastases occurring after radiofrequency ablation (RFA) of a single lung metastasis. To the best of our knowledge, these are the first such cases reported. These two patients presented with lung metastases progressive despite treatment with interleukin-2, interferon, or sorafenib but were safely ablated with percutaneous RFA under computed tomography guidance. Percutaneous RFA allowed control of the targeted tumors for >1 year. Distant lung metastases presented an objective response despite the fact that they received no targeted local treatment. Local ablative techniques, such as RFA, induce the release of tumor-degradation product, which is probably responsible for an immunologic reaction that is able to produce a response in distant tumors.

  5. Targeted Radiofrequency Ablation as an Adjunct in Treatment of Lumbar Facet Cysts

    PubMed Central

    Granville, Michelle; Berti, Aldo; Jacobson, Robert E

    2017-01-01

    Lumbar facet cysts are frequently found in patients with facet degeneration and segmental instability. When the facet cyst is localized in the neural foramina and lateral recess or becomes large, it can cause radiculopathy or neurogenic claudication. These symptomatic cysts are typically treated interventionally with drainage and a corticosteroid injection or attempts via overinflation to rupture the cyst; however, these procedures have a significant recurrence rate (up to 50%) and often need to be repeated or lead to lumbar surgery if unsuccessful.   This is the first report of using targeted radiofrequency (RF) current as an adjunct to cyst drainage. Although RF has been used for years to treat facet pain indirectly by targeting the medial facet nerve branches, with this technique, under image guidance, the actual cyst is percutaneously drained and then cauterized along with the associated facet capsule, where the original cyst developed. This has improved overall results with less cyst recurrence than previous percutaneous methods and was documented with both intermediate and long-term followup clinically and with magnetic resonance imaging (MRI) scans. This report reviews the underlying anatomy and pathology of the facet joint relating to the development of facet cysts and how current percutaneous treatments for lumbar facet cysts can be supplemented and improved by adding targeted RF ablation to the percutaneous options available to treat a lumbar facet cyst. PMID:28690952

  6. Transsacrococcygeal approach to ganglion impar: radiofrequency application for the treatment of chronic intractable coccydynia

    PubMed Central

    Adas, Cemil; Ozdemir, Ugur; Toman, Huseyin; Luleci, Nurettin; Luleci, Emel; Adas, Hilal

    2016-01-01

    Objective Coccydynia is defined as pain in the coccygeal region. Among the many causes of coccydynia, the most common cause is trauma as a result of falling on the buttocks, repetitive microtrauma, or childbirth. Several methods are currently used for the treatment of coccydynia, including nonsteroidal anti-inflammatory drugs, intrarectal manipulation, epidural injections, ganglion impar blocks, and radiofrequency treatment (RFT). Wemm and Saberski used the transacrococcygeal methods to reduce tissue trauma. RFT is a percutaneous minimally invasive procedure. In this study, we aimed to assess the effect of the transsacrococcygeal approach on ganglion impar RFT in patients with chronic coccydynia. Methods We retrospectively examined the data of 41 patients at the Department of Anesthesiology and Reanimation, Faculty of Medicine, Maltepe University (Pain Clinic), between January 1, 2010, and December 31, 2012. Results The mean age of the patients was 46.68±11.00 years (range 28–67 [46] years). The average pain duration was 3.10±1.37 years. The difference between visual analog scale scores of the pre-and postprocedure was statistically significant. In the examinations carried out in the sixth month of the treatment, 90.2% of patients had a successful outcome, whereas treatment failed in 9.8% of patients. According to our patients’ data, most of them had pain due to a trauma, were female, and overweight. Visual analog scale difference between preprocedure and early postprocedure, preprocedure and first month, preprocedure and sixth month were statistically significant (P=0.001). Conclusion Based on the lower pain scores and low complication rates after the operations, the results suggest that application of RFT on ganglion impar by the transsacrococcygeal approach is an effective and safe method for the treatment of chronic coccydynia. Patient selection, technique, and experience are the most important factors affecting the success of this method. PMID:27994479

  7. Percutaneous tracheostomy: ready or not?

    PubMed

    Pelausa, E O

    1991-04-01

    A novel approach to tracheostomy has recently been introduced, based on the Seldinger guide-wire technique. A well-packaged percutaneous tracheostomy kit promises a rapid and safe alternative to the traditional surgical tracheostomy. At the National Defence Medical Centre, this percutaneous approach was tried on four patients. Deficiencies in the kit instruments were discovered which, with the expected "learning curve," led to unexpected difficulties. Thus, the promise of percutaneous tracheostomy remains as yet unfulfilled.

  8. 78 FR 33633 - Human Exposure to Radiofrequency Electromagnetic Fields

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-04

    ... to Radiofrequency Electromagnetic Fields; Reassessment of Exposure to Radiofrequency Electromagnetic..., and 95 Human Exposure to Radiofrequency Electromagnetic Fields AGENCY: Federal Communications... electromagnetic fields. More specifically, the Commission clarifies evaluation procedures and references...

  9. Percutaneous approaches to enteral alimentation.

    PubMed

    Ponsky, J L; Gauderer, M W; Stellato, T A; Aszodi, A

    1985-01-01

    Feeding gastrostomy and jejunostomy provide effective access for long-term enteral nutrition. Traditional operative techniques for the performance of these procedures requires laparotomy and often, general anesthesia. This report describes our experience with two relatively new methods, percutaneous endoscopic gastrostomy and percutaneous endoscopic jejunostomy. Results of percutaneous gastrostomy and jejunostomy to date in 323 cases include a morbidity of 5.9 percent and a 0.3 percent operative mortality. Percutaneous endoscopic gastrostomy and jejunostomy should become the procedures of choice for the establishment of enteral access in patients requiring long-term enteral alimentation.

  10. Percutaneous gastrostomy and gastrojejunostomy.

    PubMed

    Lyon, Stuart M; Pascoe, Diane M

    2004-09-01

    Gastrostomy allows enteral nutrition to continue in patients who are unable to meet their caloric requirements orally. Though the indications for gastrostomy placement are varied, dysphagia secondary to a neurological condition is the most common. These catheters were initially placed surgically, but percutaneous endoscopic placement is now the routine in most centers. Interventional radiologists have been performing this procedure under fluoroscopic guidance for several years with encouraging results. Percutaneous radiological gastrostomy is reported to have a success rate comparable to that of the endoscopic method, with lower morbidity and mortality rates. A further benefit is that it may be performed in patients for whom the endoscopic method would be difficult or dangerous, such as those with head and neck malignancies. One of the main factors currently limiting the use of this procedure is the shortage of interventional radiology facilities and specialists.This article describes a technique for routine percutaneous radiological gastrostomy catheter placement and procedural variations for difficult cases. Indications and contraindications will be discussed, as will complication rates and how these compare with the traditional methods of gastrostomy tube placement.

  11. ANMCO/AIAC/SICI-GISE/SIC/SICCH Consensus Document: percutaneous occlusion of the left atrial appendage in non-valvular atrial fibrillation patients: indications, patient selection, staff skills, organisation, and training

    PubMed Central

    Gulizia, Michele Massimo; Molon, Giulio; Mazzone, Patrizio; Audo, Andrea; Casolo, Giancarlo; Di Lorenzo, Emilio; Portoghese, Michele; Pristipino, Christian; Ricci, Renato Pietro; Themistoclakis, Sakis; Padeletti, Luigi; Tondo, Claudio; Berti, Sergio; Oreglia, Jacopo Andrea; Gerosa, Gino; Zanobini, Marco; Ussia, Gian Paolo; Musumeci, Giuseppe; Romeo, Francesco; Di Bartolomeo, Roberto

    2017-01-01

    Abstract Atrial fibrillation (AF) is the most common arrhythmia and its prevalence is increasing due to the progressive aging of the population. About 20% of strokes are attributable to AF and AF patients are at five-fold increased risk of stroke. The mainstay of treatment of AF is the prevention of thromboembolic complications with oral anticoagulation therapy. Drug treatment for many years has been based on the use of vitamin K antagonists, but recently newer and safer molecules have been introduced (dabigatran etexilate, rivaroxaban, apixaban, and edoxaban). Despite these advances, many patients still do not receive adequate anticoagulation therapy because of contraindications (relative and absolute) to this treatment. Over the last decade, percutaneous closure of left atrial appendage, main site of thrombus formation during AF, proved effective in reducing thromboembolic complications, thus offering a valid medical treatment especially in patients at increased bleeding risk. The aim of this consensus document is to review the main aspects of left atrial appendage occlusion (selection and multidisciplinary assessment of patients, currently available methods and devices, requirements for centres and operators, associated therapies and follow-up modalities) having as a ground the significant evolution of techniques and the available relevant clinical data. PMID:28751849

  12. Percutaneous pulmonary and tricuspid valve implantations: An update

    PubMed Central

    Wagner, Robert; Daehnert, Ingo; Lurz, Philipp

    2015-01-01

    The field of percutaneous valvular interventions is one of the most exciting and rapidly developing within interventional cardiology. Percutaneous procedures focusing on aortic and mitral valve replacement or interventional treatment as well as techniques of percutaneous pulmonary valve implantation have already reached worldwide clinical acceptance and routine interventional procedure status. Although techniques of percutaneous pulmonary valve implantation have been described just a decade ago, two stent-mounted complementary devices were successfully introduced and more than 3000 of these procedures have been performed worldwide. In contrast, percutaneous treatment of tricuspid valve dysfunction is still evolving on a much earlier level and has so far not reached routine interventional procedure status. Taking into account that an “interdisciplinary challenging”, heterogeneous population of patients previously treated by corrective, semi-corrective or palliative surgical procedures is growing inexorably, there is a rapidly increasing need of treatment options besides redo-surgery. Therefore, the review intends to reflect on clinical expansion of percutaneous pulmonary and tricuspid valve procedures, to update on current devices, to discuss indications and patient selection criteria, to report on clinical results and finally to consider future directions. PMID:25914786

  13. Ultrasound guided percutaneous EVAR success is predicted by vessel diameter

    PubMed Central

    Bensley, Rodney P.; Hurks, Rob; Huang, Zhen; Pomposelli, Frank; Hamdan, Allen; Wyers, Mark; Chaikof, Elliot; Schermerhorn, Marc L.

    2012-01-01

    of percutaneous failure (16.7% of vessels < 5 mm failed vs. 2.4% of vessels ≥ 5 mm, P < .001) (OR 7.3, 95% CI [1.58-33.8], P = .01). Conclusion Ultrasound guided percutaneous EVAR can be performed in the vast majority of patients with a high success rate, shorter operative times, and fewer wound complications. Access vessel diameters less than 5 mm are at greater risk for percutaneous failure and should be treated selectively. PMID:22360918

  14. Safety and feasibility of radiofrequency ablation for treatment of Bosniak IV renal cysts

    PubMed Central

    de Menezes, Marcos Roberto; Viana, Publio Cesar Cavalcante; Yamanari, Tássia Regina; Reis, Leonardo Oliveira; Nahas, William

    2016-01-01

    ABSTRACT Purpose To describe our initial experience with radiofrequency ablation (RFA) of Bosniak IV renal cysts. Materials and Methods From 2010 to 2014, 154 renal tumor cases were treated with percutaneous thermal ablation, of which 10 cases (6.4%) from nine patients were complex renal cysts and were treated with radiofrequency ablation. Results All complex cysts were classified as Bosniak IV (four women and five men; mean age: 63.6 yrs, range: 33–83 years). One patient had a single kidney. Lesion size ranged from 1.5 to 4.1cm (mean: 2.5cm) and biopsy was performed on four cysts immediately before the procedure, all of which were malignant (two clear cell and two papillary carcinoma). Mean volume reduction of complex cysts was 25% (range: 10–40%). No patients required retreatment with RFA and no immediate or late complications were observed. The follow-up of Bosniak IV cysts had a median of 27 months (interquartile range [IQR], 23 to 38) and no recurrence or significant loss of renal function were observed. Conclusions Mid-term follow-up of the cases in our database suggests that image-guided percutaneous RFA can treat Bosniak IV cysts with very low complication rates and satisfactorily maintain renal function. PMID:27286107

  15. Pulmonary radiofrequency ablation (Part 2): Procedure and follow-up.

    PubMed

    Plasencia Martínez, J M

    2015-01-01

    Pulmonary radiofrequency ablation requires more than just interventional radiology skills. Patients must be selected carefully, and the acts that need to be done before, during, and after the procedure must be coordinated. To guarantee patient safety, radiologists need to know the variants of the technique, the precautions that must be taken, the complications that can occur, and the risks involved. Early differentiation between tumor tissue and normal changes secondary to treatment on imaging tests will make it possible to repeat the treatment without delays, and this will increase survival. This article describes how to coordinate and carry out pulmonary radiofrequency ablation, the complications of the technique, and the current evidence in follow-up. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  16. Predicting nurses' acceptance of radiofrequency identification technology.

    PubMed

    Norten, Adam

    2012-10-01

    The technology of radiofrequency identification allows for the scanning of radiofrequency identification-tagged objects and individuals without line-of-sight requirements. Healthcare organizations use radiofrequency identification to ensure the health and safety of patients and medical personnel and to uncover inefficiencies. Although the successful implementation of a system incorporating radiofrequency identification technologies requires acceptance and use of the technology, some nurses using radiofrequency identification in hospitals feel like "Big Brother" is watching them. This predictive study used a theoretical model assessing the effect of five independent variables: privacy concerns, attitudes, subjective norms, controllability, and self-efficacy, on a dependent variable, nurses' behavioral intention to use radiofrequency identification. A Web-based questionnaire containing previously validated questions was answered by 106 US RNs. Multiple linear regression showed that all constructs together accounted for 60% of the variance in nurses' intention to use radiofrequency identification. Of the predictors in the model, attitudes provided the largest unique contribution when the other predictors in the model were held constant; subjective norms also provided a unique contribution. Privacy concerns, controllability, and self-efficacy did not provide a significant contribution to nurses' behavioral intention to use radiofrequency identification.

  17. Percutaneous nephrolithotomy: technique.

    PubMed

    Knoll, Thomas; Daels, Francisco; Desai, Janak; Hoznek, Andras; Knudsen, Bodo; Montanari, Emanuele; Scoffone, Cesare; Skolarikos, Andreas; Tozawa, Keiichi

    2017-01-25

    Percutaneous nephrolithotomy (PCNL) is considered to be the first line of treatment for large renal stones. Though PCNL comes with higher morbidity, its efficacy is unbeaten by other minimally invasive modalities. However, potential complications, such as bleeding, occur. Improved skills and modifications of the procedure may reduce the probability of adverse outcomes. This article discusses the current trends and standards in PCNL technique with special focus on all important steps as positioning, access, instruments, dilation, disintegration, and exit, including outcomes, complication management, and training modalities.

  18. Radiofrequency Ablation Combined with Renal Arterial Embolization for the Treatment of Unresectable Renal Cell Carcinoma Larger Than 3.5 cm: Initial Experience

    SciTech Connect

    Yamakado, Koichiro Nakatsuka, Atsuhiro; Kobayashi, Shigeki; Akeboshi, Masao; Takaki, Haruyuki; Kariya, Zentaro; Kinbara, Hiroyuki; Arima, Kiminobu; Yanagawa, Makoto; Hori, Yasuhide; Kato, Hiromi; Sugimura, Yoshiki; Takeda, Kan

    2006-06-15

    The purpose of the study was to evaluate the feasibility, safety, and therapeutic effects of the combination of renal arterial embolization and radiofrequency (RF) ablation to reinforce the anticancer effect on renal cell carcinomas (RCCs) measuring 3.5 cm or larger. This study was undertaken to evaluate this combined therapy on large RCCs-based tumor geometry. Eleven patients with 12 RCCs 3.5 cm or larger in diameter (3.5-9.0 cm) underwent combined therapy. Two were exophytic tumors, and the remaining 10 tumors had components extending into the renal sinus fat. Tumor vessels were selectively embolized in nine patients and the renal artery was completely embolized in two patients with polyvinyl alcohol or ethanol mixed with iodized oil. RF ablation was percutaneously done under the computed tomographic (CT)-fluoroscopic guidance. Response to treatment was evaluated by dynamic contrast-enhanced CT and magnetic resonance (MR) imaging. Tumor enhancement was eliminated after a single RF session in nine tumors (75%), after two sessions in two tumors (17%), and after four sessions in one tumor (8%). Both exophytic tumors (100%) and 7 of 10 tumors having components in the renal sinus fat (70%) were completely ablated with a single RF session. All tumors remained controlled during a mean follow-up period of 13 months and showed significant reduction in tumor sizes (5.2 {+-} 1.7 cm to 3.6 {+-} 1.4 cm, p < 0.001). A delayed abscess developed in the ablated lesion in a patient, which was percutaneously drainaged. Combined therapy as described in this report is a feasible, relatively safe, and promising treatment method for large RCCs regardless of tumor geometry.

  19. Lumbar and sacral radiofrequency neurotomy.

    PubMed

    Mazin, David A; Sullivan, Joseph P

    2010-11-01

    Radiofrequency (RF) neurotomy is an interventional procedure used to alleviate certain types of low back pain. RF energy is used to thermally coagulate the specific nerves that transmit pain signals. Recent evidence has shown that this procedure demonstrates significant efficacy in relieving low back pain in lumbar zygapophysial joints, and research is ongoing to determine if pain relief for the sacroiliac joint is also possible. This article provides an evidence-based background for performing RF neurotomy, discusses the relevant anatomy, and highlights the indications and technique for lumbar and sacral RF neurotomy. Copyright © 2010 Elsevier Inc. All rights reserved.

  20. Radio-Frequency Strain Monitor

    NASA Technical Reports Server (NTRS)

    Heyman, Joseph S.; Rogowski, Robert S.; Holben, Milford S., Jr.

    1988-01-01

    Radio-frequency (RF) strain monitor developed to measure lengths of objects. RF waveguide or cable bonded to structure monitored. Propagation of RF signal along waveguide results in phase shift proportional to length of path traveled. Impedance mismatches placed in RF cable at nodes of structure. Records mismatches and detects overall length of line and lengths of intervals between nodes. Used to detect changes in elements of large structure with single cable. Monitor has potential for many applications, including monitoring stability of such large structures as aircraft, bridges, and buildings in Earthquake zones.

  1. Laser Navigation for Radiofrequency Ablation

    SciTech Connect

    Varro, Zoltan; Locklin, Julia K. Wood, Bradford J.

    2004-09-15

    A 45-year-old male with renal cell carcinoma secondary to von-Hippel Lindau (VHL) disease presented for radiofrequency ablation (RFA) of kidney tumors. Due to his prior history of several partial nephrectomies and limited renal reserve, RFA was chosen because of its relatively nephron-sparing nature. A laser guidance device was used to help guide probe placement in an attempt to reduce procedure time and improve targeting accuracy. The device was successful at guiding needle placement, as both tumors were located with a single pass. Follow-up CT scan confirmed accurate needle placement, showing an area of coagulation necrosis covering the previously seen tumor.

  2. Radiofrequency Ablation for Liver Cancer.

    PubMed

    Jacobs, Amy

    2015-01-01

    Interventional ablative technologies aided by imaging techniques such as ultrasonography, computed tomography, and magnetic resonance imaging have been crucial in managing patients with primary liver cancer and liver metastases over the past 20 years. Several ablative technologies have been used to treat liver cancer; however, radiofrequency ablation (RFA) has emerged as the most common ablative therapy for hepatic lesions, both in the United States and globally. RFA is the treatment of choice for patients who cannot have surgical resection of the liver. This article focuses on the role of imaging in RFA treatment of primary and metastatic hepatic lesions.

  3. Percutaneous renal sympathetic nerve ablation for loin pain haematuria syndrome.

    PubMed

    Gambaro, Giovanni; Fulignati, Pierluigi; Spinelli, Alessio; Rovella, Valentina; Di Daniele, Nicola

    2013-09-01

    Loin pain haematuria syndrome (LPHS) is a severe renal pain condition of uncertain origin and often resistant to treatment. Nephrectomy and renal autotrasplantation have occasionally been performed in very severe cases. Its pathogenesis is controversial. A 40-year-old hypertensive lady was diagnosed with LPHS after repeated diagnostic imaging procedures had ruled out any renal, abdominal or spinal conditions to justify pain. Notwithstanding treatment with three drugs, she had frequent hypertensive crises during which the loin pain was dramatically exacerbated. Vascular causes of the pain and hypertension were investigated and excluded. Her renal function was normal. The patient was referred to a multidisciplinary pain clinic, but had no significant improvement in her pain symptoms despite the use of non-steroidal anti-inflammatory drugs, adjuvant antidepressants and opioid-like agents. The pain and the discomfort were so severe that her quality of life was very poor, and her social and professional activities were compromised. Nephrectomy and renal autotransplantation have occasionally been performed in these cases. Since visceral pain signals flow through afferent sympathetic fibres, we felt that percutaneous catheter-based radiofrequency ablation of the renal sympathetic nerve fibres (recently introduced for the treatment of drug-resistant hypertension) could be valuable for pain relief. We treated the patient with radiofrequency ablation (Medtronic Symplicity Catheter) applied only to the right renal artery. After a 6-month follow-up, the patient is pain free and normotensive with all drugs withdrawn. She has experienced no hypertensive crises in the meantime. This observation suggests that percutaneous sympathetic denervation could prove to be an effective mini-invasive strategy for the treatment of chronic renal pain, and LPHS in particular.

  4. [Ultrasound guided percutaneous nephrolithotripsy].

    PubMed

    Guliev, B G

    2014-01-01

    The study was aimed to the evaluation of the effectiveness and results of ultrasound guided percutaneous nephrolithotripsy (PNL) for the treatment of patients with large stones in renal pelvis. The results of PNL in 138 patients who underwent surgery for kidney stones from 2011 to 2013 were analyzed. Seventy patients (Group 1) underwent surgery with combined ultrasound and radiological guidance, and 68 patients (Group 2)--only with ultrasound guidance. The study included patients with large renal pelvic stones larger than 2.2 cm, requiring the formation of a single laparoscopic approach. Using the comparative analysis, the timing of surgery, the number of intra- and postoperative complications, blood loss and length of stay were evaluated. Percutaneous access was successfully performed in all patients. Postoperative complications (exacerbation of chronic pyelonephritis, gross hematuria) were observed in 14.3% of patients in Group 1 and in 14.7% of patients in Group 2. Bleeding requiring blood transfusion, and injuries of adjacent organs were not registered. Efficacy of PNL in the Group 1 was 95.7%; 3 (4.3%) patients required additional interventions. In Group 2, the effectiveness of PNL was 94.1%, 4 (5.9%) patients additionally underwent extracorporeal lithotripsy. There were no significant differences in the effectiveness of PNL, the volume of blood loss and duration of hospitalization. Ultrasound guided PNL can be performed in large pelvic stones and sufficient expansion of renal cavities, thus reducing radiation exposure of patients and medical staff.

  5. Complications in percutaneous nephrolithotomy.

    PubMed

    Kyriazis, Iason; Panagopoulos, Vasilios; Kallidonis, Panagiotis; Özsoy, Mehmet; Vasilas, Marinos; Liatsikos, Evangelos

    2015-08-01

    Percutaneous nephrolithotomy (PCNL) is generally considered a safe technique offering the highest stone-free rates after the first treatment as compared to the other minimal invasive lithotripsy techniques. Still, serious complications although rare should be expected following this percutaneous procedure. In this work, the most common and important complications associated with PCNL are being reviewed focusing on the perioperative risk factors, current management, and preventing measures that need to be taken to reduce their incidence. In addition, complication reporting is being criticized given the absence of a universal consensus on PCNL complications description. Complications such as perioperative bleeding, urine leak from nephrocutaneous fistula, pelvicalyceal system injury, and pain are individually graded as complications by various authors and are responsible for a significant variation in the reported overall PCNL complication rate, rendering comparison of morbidity between studies almost impossible. Due to the latter, a universally accepted grading system specialized for the assessment of PCNL-related complications and standardized for each variation of PCNL technique is deemed necessary.

  6. Pulmonary artery perforation by plug anchoring system after percutaneous closure of left appendage.

    PubMed

    Bianchi, Giacomo; Solinas, Marco; Gasbarri, Tommaso; Bevilacqua, Stefano; Tiwari, Kaushal Kishore; Berti, Sergio; Glauber, Mattia

    2013-07-01

    Patients receiving oral anticoagulant therapy for atrial fibrillation who are at high risk of bleeding are increasingly referred for percutaneous left atrial appendage exclusion. Although effective, this procedure is not free from risk. We report a case of pericardial tamponade due to pulmonary artery tear caused by a trespassing anchoring hook of an AGA plug. Intraoperatively, no actual bleeding was found from the left appendage, a proof of its complete occlusion by the device. The patient underwent successful surgical repair and radio-frequency ablation of atrial fibrillation was performed by pulmonary veins encircling. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  7. Benign Spine Lesions: Advances in Techniques for Minimally Invasive Percutaneous Treatment.

    PubMed

    Tomasian, A; Wallace, A N; Jennings, J W

    2017-02-09

    Minimally invasive percutaneous imaging-guided techniques have been shown to be safe and effective for the treatment of benign tumors of the spine. Techniques available include a variety of tumor ablation technologies, including radiofrequency ablation, cryoablation, microwave ablation, alcohol ablation, and laser photocoagulation. Vertebral augmentation may be performed after ablation as part of the same procedure for fracture stabilization or prevention. Typically, the treatment goal in benign spine lesions is definitive cure. Painful benign spine lesions commonly encountered in daily practice include osteoid osteoma, osteoblastoma, vertebral hemangioma, aneurysmal bone cyst, Paget disease, and subacute/chronic Schmorl node. This review discusses the most recent advancement and use of minimally invasive percutaneous therapeutic options for the management of benign spine lesions.

  8. Pneumoperitoneum with Subcutaneous Emphysema after Percutaneous Endoscopic Gastrostomy

    PubMed Central

    Karip, Bora; Ozcabi, Yetkin; Ağca, Birol; Alahdab, Yesim; Memisoglu, Kemal

    2014-01-01

    Percutaneous endoscopic gastrostomy is a safe way for enteral nutrition in selected patients. Generally, complications of this procedure are very rare but due to patients general health condition, delayed diagnosis and treatment of complications can be life threatening. In this study, we present a PEG-related massive pneumoperitoneum and subcutaneous emphysema in a patient with neuro-Behçet. PMID:25120935

  9. Rationale for Percutaneous Intervention of CTO.

    PubMed

    Waram, Kethes C; Willis, Nicholas P; Girotra, Sudhakar; Shaker, Rimon L; Pershad, Ashish

    2012-07-01

    Chronic total occlusion accounts for 15% of cases during diagnostic angiography with higher referral rate to surgical revascularization. With contemporary strategies and techniques, the success rate with experienced operators can exceed 90%. Currently available observational studies in carefully selected patient populations show evidence of a trend toward symptom relief; improvement in quality of life, left ventricular function, and mortality; and improved tolerance toward future ischemic events. Lack of randomized controlled trials comparing current optimal medical management with percutaneous coronary intervention for chronic total occlusion is a major barrier to widespread adaptation of this advanced complex interventional technique. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Recent Advances in Percutaneous Cardioscopy.

    PubMed

    Uchida, Yasumi

    2011-08-01

    Percutaneous cardioscopy, using high-resolution fiberoptic imaging, enables direct visualization of the cardiac interior, thereby enabling macroscopic pathological diagnosis. Percutaneous cardioscopy has demonstrated that the endocardial surface exhibits various colors characteristic of different heart diseases. This imaging modality can now be used for evaluation of the severity of myocardial ischemia, and staging of myocarditis. Myocardial blood flow recovery induced by vasodilating agents or percutaneous coronary interventions can be clearly visualized. Morphological and functional changes in the cardiac valves can also be evaluated. Cardioscope-guided endomyocardial biopsy enables pin-point biopsy of the diseased myocardium. Recently, dye-image cardioscopy and fluorescence cardioscopy were developed for evaluation of the subendocardial microcirculation. Cardioscope-guided intracardiac therapies such as myotomy, myectomy, valvulotomy, and transendocardial angiogenic and myogenic therapy have been trialed using animal models in anticipation of future clinical applications. Percutaneous cardioscopy has the potential to contribute to our understanding of heart disease, and to assist in guidance for intracardiac therapies.

  11. Percutaneous transluminal coronary angioplasty (PTCA)

    MedlinePlus Videos and Cool Tools

    Percutaneous transluminal coronary angioplasty (PTCA) is a minimally invasive procedure to open up blocked coronary arteries, allowing blood to circulate unobstructed to the heart muscle. The procedure begins with ...

  12. Percutaneous Nephrolithotomy in Children

    PubMed Central

    DeMarco, Romano T.

    2011-01-01

    The surgical management of pediatric stone disease has evolved significantly over the last three decades. Prior to the introduction of shockwave lithotripsy (SWL) in the 1980s, open lithotomy was the lone therapy for children with upper tract calculi. Since then, SWL has been the procedure of choice in most pediatric centers for children with large renal calculi. While other therapies such as percutaneous nephrolithotomy (PNL) were also being advanced around the same time, PNL was generally seen as a suitable therapy in adults because of the concerns for damage in the developing kidney. However, recent advances in endoscopic instrumentation and renal access techniques have led to an increase in its use in the pediatric population, particularly in those children with large upper tract stones. This paper is a review of the literature focusing on the indications, techniques, results, and complications of PNL in children with renal calculi. PMID:22013438

  13. Ablation effects of noninvasive radiofrequency field-induced hyperthermia on liver cancer cells.

    PubMed

    Chen, Kaiyun; Zhu, Shuguang; Xiang, Guoan; Duan, Xiaopeng; He, Jiwen; Chen, Guihua

    2016-05-01

    To have in-depth analysis of clinical ablation effect of noninvasive radiofrequency field-induced hyperthermia on liver cancer cells, this paper collected liver cancer patients' treatment information from 10 hospitals during January 2010 and December 2011, from which 1050 cases of patients were randomly selected as study object of observation group who underwent noninvasive radiofrequency field-induced hyperthermia treatment; in addition, 500 cases of liver cancer patients were randomly selected as study object of control group who underwent clinical surgical treatment. After treatment was completed, three years of return visit were done, survival rates of the two groups of patients after 1 year, 2 years, and 3 years were compared, and clinical effects of radiofrequency ablation of liver cancer were evaluated. Zoom results show that the two groups are similar in terms of survival rate, and the difference is without statistical significance. 125 patients in observation group had varying degrees of adverse reactions, while 253 patients in control group had adverse reactions. There was difference between groups P < 0.05, with significant statistical significance. It can be concluded that radiofrequency ablation of liver cancer is more secure. Therefore, the results of this study fully demonstrate that liver cancer treatment with noninvasive radiofrequency field-induced hyperthermia is with safety effect and satisfactory survival rate, thus with relatively high clinical value in clinical practice.

  14. Percutaneous approaches to valve repair for mitral regurgitation.

    PubMed

    Feldman, Ted; Young, Amelia

    2014-05-27

    Percutaneous therapy has emerged as an option for treatment of mitral regurgitation for selected, predominantly high-risk patients. Most of the percutaneous approaches are modifications of existing surgical approaches. Catheter-based devices mimic these surgical approaches with less procedural risk, due to their less-invasive nature. Percutaneous annuloplasty can be achieved indirectly via the coronary sinus or directly from retrograde left ventricular access. Catheter-based leaflet repair with the MitraClip (Abbott Laboratories, Abbott Park, Illinois) is accomplished with an implantable clip to mimic the surgical edge-to-edge leaflet repair technique. A large experience with MitraClip has been reported, and several other percutaneous approaches have been successfully used in smaller numbers of patients to demonstrate proof of concept, whereas others have failed and are no longer under development. There is increasing experience in both trials and practice to begin to define the clinical utility of percutaneous leaflet repair, and annuloplasty approaches are undergoing significant development. Transcatheter mitral valve replacement is still in early development.

  15. Sympathetic radiofrequency neurolysis for unilateral lumbar hyperhidrosis: a case report.

    PubMed

    Aşik, Züleyha Soytürk; Orbey, Başak Ceyda; Aşik, Ibrahim

    2008-07-01

    Patients with hyperhidrosis suffer from physical, social and mental discomfort which often cannot be treated sufficiently using conservative measures. A new percutaneous approach to sympathectomy using radiofrequency denervation has seemed to offer longer duration of action and less incidence of post sympathetic neuralgia. This article reports the authors' experience with sympathetic RF neurolysis in a 35 year old male with right unilateral lumbar hyperhidrosis. Under scopy guided localization of the lumbar spine sympathetic blockade with local anesthetics to L2-5 vertebral levels were performed as a diagnostic block. Lesion effectiveness is monitored by bilateral feet skin temperature measurement. Clinical effects produced by the first sympathetic ganglion block were sustained for 1 week and then RF neurolysis of lumbar sympathetic ganglion was performed to the same levels for a longer effect. The procedure was accomplished within 30 minutes and the patient was discharged within 2 hours after the procedure. Hyperhidrosis was relieved after the procedure and there were no postsympathectomy neuralgia and sexual dysfunction. The patient obtained improvement of lumbar hyperhidrosis at his first month of follow- up and was satisfied with the outcome. In conclusion, RF neurolysis of lumbar sympathetic ganglions is a safe and effective palliative procedure with minimal invasiveness for relieving excessive sweat secretion in patients with localized hyperhidrosis.

  16. Tageted bipolar radiofrequency decompression with vertebroplasty for intractable radicular pain due to spinal metastasis: a case report

    PubMed Central

    Baek, Seong Jin; Lee, Eun Young

    2016-01-01

    Metastatic spinal tumors are usually quite difficult to treat. In patients with metastatic spinal tumors, conventional radiotherapy fails to relieve pain in 20–30% of cases and open surgery often causes considerable trauma and complications, which delays treatment of the primary disease. Percutaneous vertebroplasty (PVP) is considered to be useful in achieving rapid pain control and preventing further vertebral collapse due to spinal metastasis. However, symptoms of intraspinal neural compression can be contraindications to PVP. To overcome this problem, we performed PVP following targeted bipolar radiofrequency decompression, and examined the effect of the combined treatment in relieving severe radicular pain related to spinal cord compression caused by malignant metastatic tumors. PMID:27482319

  17. Increased number of cerebral emboli during percutaneous endocardial pulmonary vein isolation versus a thoracoscopic epicardial approach.

    PubMed

    Sauren, Loes D; la Meir, Mark; de Roy, Luc; Pison, Laurent; van der Veen, Frederik H; Mess, Werner H; Crijns, Harry J; Maessen, Jos G

    2009-11-01

    Pulmonary vein isolation (PVI) using ablation energy appears an effective treatment for atrial fibrillation (AF) with a success rate of approximately 80%. However, post-procedural neurological complications still occur in 0.5-10% of all patients undergoing PVI, presumably due to embolism. Therefore, we investigated the occurrence of cerebral micro-embolic signals (MES) as a surrogate marker for the risk of neurological impairment of two different PVI methods: (1) percutaneous endocardial radio-frequency (RF) ablation and (2) thoracoscopic epicardial ablation using RF energy. Ten patients (eight persistent AF and two paroxysmal AF) underwent a minimally invasive thoracoscopic epicardial (EPI) RF ablation and 10 patients (one persistent AF and nine paroxysmal AF) underwent a percutaneous endocardial (ENDO) isolation. Transcranial Doppler (TCD) was used to detect an MES in the middle cerebral arteries. An average of 5 (+/-6) MES were detected during epicardial PVI procedure versus 3908 (+/-2816) MES during percutaneous endocardial PVI procedure. During the ablation application period, respectively, 1 (+/-1) and 2566 (+/-2296) cerebral MES were detected. Cerebral micro-emboli during epicardial ablation are almost absent when compared to the thousands of emboli measured during percutaneous endocardial ablation.

  18. Radiofrequency Ablation of Metastatic Pheochromocytoma

    PubMed Central

    Venkatesan, Aradhana M.; Locklin, Julia; Lai, Edwin W.; Adams, Karen T.; Fojo, Antonio Tito; Pacak, Karel; Wood, Bradford J.

    2013-01-01

    In the present report on the preliminary safety and effectiveness of radiofrequency (RF) ablation for pheochromocytoma metastases, seven metastases were treated in six patients (mean size, 3.4 cm; range, 2.2–6 cm). α- and β-adrenergic and catecholamine synthesis inhibition and intraprocedural anesthesia monitoring were used. Safety was assessed by recording ablation-related complications. Complete ablation was defined as a lack of enhancement within the ablation zone on follow-up computed tomography. No serious adverse sequelae were observed. Complete ablation was achieved in six of seven metastases (mean follow-up, 12.3 months; range, 2.5–28 months). In conclusion, RF ablation may be safely performed for metastatic pheochromocytoma given careful attention to peri-procedural management. PMID:19875067

  19. Radiofrequency Ablation: A Nursing Perspective

    PubMed Central

    Locklin, Julia K.; Wood, Bradford J.

    2008-01-01

    Radiofrequency ablation (RFA) has emerged as a safe and predictable technology for treating certain patients with cancer who otherwise have few treatment options. Nurses need to be familiar with all phases of the RFA procedure to create an optimal environment for patients. This article offers a brief review of the RFA procedure and nurses' responsibilities in caring for these patients. Before RFA, nurses should focus on patient education and aggressive hydration. During the procedure, nurses can prevent injury by placing grounding pads appropriately, monitoring vital signs, and medicating patients as needed. After RFA, nurses should assess the skin puncture site, provide adequate pain relief, and, again, hydrate patients. Nurses who care appropriately for RFA recipients may help to improve patient outcomes and make an otherwise frightening procedure more comfortable. PMID:15973845

  20. Percutaneous epicardial ablation in ventricular arrhythmias.

    PubMed

    Galvão Santos, Pedro; Cavaco, Diogo; Adragão, Pedro; Scanavacca, Mauricio; Reis Santos, Katya; Belo Morgado, Francisco; Carmo, Pedro; Costa, Francisco; Bernardo, Ricardo; Nunes, Manuela; Abecasis, Miguel; Neves, José; Mendes, Miguel

    2014-05-01

    Reentrant circuits of ventricular tachycardia may involve not only the endocardium but also the epicardium. Epicardial ablation can be useful in these situations. The aim of this study was to assess efficacy, safety and complications in a series of consecutive patients who underwent ablation of ventricular tachycardia with epicardial mapping. The study included all patients undergoing ventricular tachycardia ablation with epicardial mapping from 2004 to 2012. Of a total of 95 ablations, an epicardial approach was attempted in nine patients, eight male, mean age 58±12 years. Endocardial mapping was performed in all patients previously or simultaneously. The etiology of the arrhythmia was non-ischemic in eight patients and ischemic in one. We compared the number of events in the six months prior to the epicardial procedure and six months after. Percutaneous epicardial access was achieved in eight patients. In one case it was not possible due to the presence of adhesions. In none of the patients was the procedure repeated and there were no major complications during hospitalization. In a mean follow-up of 3.5±1.2 years, one patient suffered stroke; there were no other medium-to-long-term complications and the number of ventricular tachycardia episodes was reduced in all patients after ablation. Epicardial radiofrequency ablation of ventricular tachycardia was effective in reducing morbidity in eight patients, with a low risk of complications in the short and medium-to-long term. Copyright © 2012 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  1. Esophageal papilloma: Flexible endoscopic ablation by radiofrequency

    PubMed Central

    del Genio, Gianmattia; del Genio, Federica; Schettino, Pietro; Limongelli, Paolo; Tolone, Salvatore; Brusciano, Luigi; Avellino, Manuela; Vitiello, Chiara; Docimo, Giovanni; Pezzullo, Angelo; Docimo, Ludovico

    2015-01-01

    Squamous papilloma of the esophagus is a rare benign lesion of the esophagus. Radiofrequency ablation is an established endoscopic technique for the eradication of Barrett esophagus. No cases of endoscopic ablation of esophageal papilloma by radiofrequency ablation (RFA) have been reported. We report a case of esophageal papilloma successfully treated with a single session of radiofrequency ablation. Endoscopic ablation of the lesion was achieved by radiofrequency using a new catheter inserted through the working channel of endoscope. The esophageal ablated tissue was removed by a specifically designed cup. Complete ablation was confirmed at 3 mo by endoscopy with biopsies. This case supports feasibility and safety of as a new potential indication for BarrxTM RFA in patients with esophageal papilloma. PMID:25789102

  2. Computerized tomography-guided sphenopalatine ganglion pulsed radiofrequency treatment in 16 patients with refractory cluster headaches: Twelve- to 30-month follow-up evaluations.

    PubMed

    Fang, Luo; Jingjing, Lu; Ying, Shen; Lan, Meng; Tao, Wang; Nan, Ji

    2016-02-01

    Sphenopalatine ganglion percutaneous radiofrequency thermocoagulation treatment can improve the symptoms of cluster headaches to some extent. However, as an ablation treatment, radiofrequency thermocoagulation treatment also has side effects. To preliminarily evaluate the efficacy and safety of a non-ablative computerized tomography-guided pulsed radiofrequency treatment of sphenopalatine ganglion in patients with refractory cluster headaches. We included and analysed 16 consecutive cluster headache patients who failed to respond to conservative therapy from the Pain Management Center at the Beijing Tiantan Hospital between April 2012 and September 2013 treated with pulsed radiofrequency treatment of sphenopalatine ganglion. Eleven of 13 episodic cluster headaches patients and one of three chronic cluster headaches patient were completely relieved of the headache within an average of 6.3 ± 6.0 days following the treatment. Two episodic cluster headache patients and two chronic cluster headache patients showed no pain relief following the treatment. The mean follow-up time was 17.0 ± 5.5 months. All patients enrolled in this study showed no treatment-related side effects or complications. Our data show that patients with refractory episodic cluster headaches were quickly, effectively and safely relieved from the cluster period after computerized tomography-guided pulsed radiofrequency treatment of sphenopalatine ganglion, suggesting that it may be a therapeutic option if conservative treatments fail. © International Headache Society 2015.

  3. Characterization of tracked radiofrequency ablation in phantom

    SciTech Connect

    Chen, Chun-Cheng R.; Miga, Michael I.; Galloway, Robert L.

    2007-10-15

    In radiofrequency ablation (RFA), successful therapy requires accurate, image-guided placement of the ablation device in a location selected by a predictive treatment plan. Current planning methods rely on geometric models of ablations that are not sensitive to underlying physical processes in RFA. Implementing plans based on computational models of RFA with image-guided techniques, however, has not been well characterized. To study the use of computational models of RFA in planning needle placement, this work compared ablations performed with an optically tracked RFA device with corresponding models of the ablations. The calibration of the tracked device allowed the positions of distal features of the device, particularly the tips of the needle electrodes, to be determined to within 1.4{+-}0.6 mm of uncertainty. Ablations were then performed using the tracked device in a phantom system based on an agarose-albumin mixture. Images of the sliced phantom obtained from the ablation experiments were then compared with the predictions of a bioheat transfer model of RFA, which used the positional data of the tracked device obtained during ablation. The model was demonstrated to predict 90% of imaged pixels classified as being ablated. The discrepancies between model predictions and observations were analyzed and attributed to needle tracking inaccuracy as well as to uncertainties in model parameters. The results suggest the feasibility of using finite element modeling to plan ablations with predictable outcomes when implemented using tracked RFA.

  4. Radiofrequency radiation leakage from microwave ovens.

    PubMed

    Lahham, Adnan; Sharabati, Afifeh

    2013-12-01

    This work presents data on the amount of radiation leakage from 117 microwave ovens in domestic and restaurant use in the West Bank, Palestine. The study of leakage is based on the measurements of radiation emissions from the oven in real-life conditions by using a frequency selective field strength measuring system. The power density from individual ovens was measured at a distance of 1 m and at the height of centre of door screen. The tested ovens were of different types, models with operating powers between 1000 and 1600 W and ages ranging from 1 month to >20 y, including 16 ovens with unknown ages. The amount of radiation leakage at a distance of 1 m was found to vary from 0.43 to 16.4 μW cm(-2) with an average value equalling 3.64 μW cm(-2). Leakages from all tested microwave ovens except for seven ovens (∼6 % of the total) were below 10 μW cm(-2). The highest radiation leakage from any tested oven was ∼16.4 μW cm(-2), and found in two cases only. In no case did the leakage exceed the limit of 1 mW cm(-2) recommended by the ICNIRP for 2.45-GHz radiofrequency. This study confirms a linear correlation between the amount of leakage and both oven age and operating power, with a stronger dependence of leakage on age.

  5. Radiofrequency ablation of the basivertebral nerve as potential treatment of back pain: pathologic assessment in an ovine model (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Hoopes, P. J.; Eskey, Cliff J.; Attawia, Mohammed; Patel, Samit J.; Ryan, T. P.; Pellegrino, Richard; Bergeron, Jeffrey A.

    2005-04-01

    Pathological involvement of the basivertebral nerve (BVN), an intraosseous vertebral nerve, may play a significant role in some forms of back pain. This study was designed to assess the feasibility and effects of thermal ablation of the lumbar basivertebral nerve in mature sheep. Sixteen adult female sheep weighing 65-80 kg were anesthetized and positioned for ventral recumbent surgery. Under fluoroscopic guidance, two bilarterally oposed 5mm active length rediofrequency (RF) electrodes (1.65mm diameter were perfutaneously placed in select lumbar vertebrae at a relative angle of 70 degrees with a 5 mm tip separation. The elctrodes were advanced to the region of the vertebral bodies which contained the BVN. A thermal dose of 95° C/720 seconds was administered. Animals were survived for 2, 14, 90, or 180 days post-treatment. Clinical, radiologic and pathologic investigations were performed to determine the effect of the heat on the BVN and associated tissues. Thermal damage to the basivertebral neurovascular bundle was characterized by early hemorrhage and necrosis, followed by inflammation and fibrosis. Although there wasa significant revascularization of the treated bone marow regions, there was no evidence of basivertebral nerve survival or regeneration regeneration. In addition to ablation of teh basivertebral nerovascular bundle, the areas receiving the greatest treatment demonstrated initial mild local osteolysis and demineralization of the vertebral body bone and regional depopulation of the vertebral bone marrow cellular elements. Significant bone remodeling in the affected areas had begun by 14 days post-treatment. Bone remodeling was characterized by conventional osteoblast proliferation, osteoid deposition, and mineralization. This study demonstrated the ability to accurately, reproducibly, and safely ablate the basivertebral nerve and neurovascular bundle in mature sheep using a fluoroscopically guided percutaneously delivered radiofrequency technique.

  6. Image-guided radiofrequency ablation for adrenocortical adenoma with Cushing syndrome: outcomes after mean follow-up of 33 months.

    PubMed

    Arima, Kiminobu; Yamakado, Kouichirou; Suzuki, Ryuichi; Matsuura, Hiroshi; Nakatsuka, Atsuhiro; Takeda, Kan; Sugimura, Yoshiki

    2007-09-01

    To evaluate the feasibility, safety, and therapeutic effects of image-guided radiofrequency (RF) ablation used for the treatment of adrenocortical adenoma with Cushing syndrome. From February 2003 to May 2005, 4 consecutive patients with adrenocortical adenoma and Cushing syndrome received percutaneous RF ablation. All tumors were in the left adrenal gland, with a mean tumor size of 2.7 +/- 0.6 cm (range 2.0 to 3.5). The RF ablation was performed under real-time computed tomography fluoroscopic guidance. Technical success was defined as disappearance of tumor enhancement on contrast-enhanced computed tomography imaging acquired within 1 week after RF ablation. Clinical success was defined as improvement in serum cortisol and adrenocorticotropic hormone values and symptoms at the end of follow-up. Tumor enhancement disappeared after initial RF ablation in 3 of 4 patients (technical success rate 75%). The fourth patient underwent a repeat RF ablation session 3 years later, resulting in eradication of tumor enhancement. Both the serum cortisol and adrenocorticotropic hormone levels returned to normal and the symptoms related to Cushing syndrome had disappeared at the end of follow-up (range 20 to 46 months, mean 33) for a clinical success rate of 100%. All tumors showed involution (2.2 +/- 0.3 cm) at the end of the study. No major complications occurred related to the procedures except for pneumothorax requiring chest tube placement for 3 days. Using RF ablation for adrenocortical adenoma with Cushing syndrome is a feasible, safe, and promising treatment method in selected patients.

  7. Factors influencing lesion formation during radiofrequency catheter ablation.

    PubMed

    Eick, Olaf J

    2003-07-01

    In radiofrequency (RF) ablation, the heating of cardiac tissue is mainly resistive. RF current heats cardiac tissue and in turn the catheter electrode is being heated. Consequently, the catheter tip temperature is always lower--or ideally equal--than the superficial tissue temperature. The lesion size is influenced by many parameters such as delivered RF power, electrode length, electrode orientation, blood flow and tissue contact. This review describes the influence of these different parameters on lesion formation and provides recommendations for different catheter types on selectable parameters such as target temperatures, power limits and RF durations.

  8. Factors Influencing Lesion Formation During Radiofrequency Catheter Ablation

    PubMed Central

    Eick, Olaf J

    2003-01-01

    In radiofrequency (RF) ablation, the heating of cardiac tissue is mainly resistive. RF current heats cardiac tissue and in turn the catheter electrode is being heated. Consequently, the catheter tip temperature is always lower - or ideally equal - than the superficial tissue temperature. The lesion size is influenced by many parameters such as delivered RF power, electrode length, electrode orientation, blood flow and tissue contact. This review describes the influence of these different parameters on lesion formation and provides recommendations for different catheter types on selectable parameters such as target temperatures, power limits and RF durations. PMID:16943910

  9. Thyroid Radiofrequency Ablation: Updates on Innovative Devices and Techniques

    PubMed Central

    Park, Hye Sun; Park, Auh Whan; Chung, Sae Rom; Choi, Young Jun; Lee, Jeong Hyun

    2017-01-01

    Radiofrequency ablation (RFA) is a well-known, effective, and safe method for treating benign thyroid nodules and recurrent thyroid cancers. Thyroid-dedicated devices and basic techniques for thyroid RFA were introduced by the Korean Society of Thyroid Radiology (KSThR) in 2012. Thyroid RFA has now been adopted worldwide, with subsequent advances in devices and techniques. To optimize the treatment efficacy and patient safety, understanding the basic and advanced RFA techniques and selecting the optimal treatment strategy are critical. The goal of this review is to therefore provide updates and analysis of current devices and advanced techniques for RFA treatment of benign thyroid nodules and recurrent thyroid cancers. PMID:28670156

  10. Radiofrequency ablation of hepatic metastasis: results of treatment in forty patients.

    PubMed

    Rath, G K; Julka, P K; Thulkar, S; Sharma, D N; Bahl, Amit; Bhatnagar, S

    2008-01-01

    To evaluate the local control of hepatic metastasis with radiofrequency ablation treatment. We did a retrospective analysis in 40 patients treated with radiofrequency ablation for hepatic metastasis. The tumors ablated included up to two metastatic liver lesions, with primaries in breast, gastrointestinal tract, cervix, etc. Radiofrequency ablation was performed under general anesthesia in all cases, using ultrasound guidance. Radionics Cool-Tip RF System was used to deliver the treatment. The median age of patients treated was 49 years. There were 13 female and 27 male patients. The median tumor size ablated was 1.5 cm (0.75-4.0 cm). A total of 52 radiofrequency ablation cycles were delivered. Successful ablation was achieved in all patients with hepatic metastasis less than 3 cm in size. Pain was the most common complication seen (75%). One patients developed skin burns. At 2-year follow-up 7.5% of patients had locally recurrent disease. Radiofrequency ablation is a minimally invasive treatment modality. It can be useful in a select group of patients with solitary liver metastasis of less than 3 cm size.

  11. Safety and efficacy of a non-contact radiofrequency device for body contouring in Asians.

    PubMed

    Suh, Dong Hye; Kim, Chang Min; Lee, Sang Jun; Kim, Hyunjoo; Yeom, Suk Keu; Ryu, Hwa Jung

    2017-04-01

    The non-invasive reduction of subcutaneous abdominal fat became popular. Radiofrequency, non-contact, selective-field device Vanquish® has been developed to selectively induce deep fat tissue heating to reduce waist circumference. The objective of this study was to evaluate the efficacy and safety of clinical, radiological results of the radiofrequency, non-contact, selective-field device treatment. Twelve healthy individuals with no underlying medical problem were treated with five sessions of radiofrequency treatment to reduce abdominal subcutaneous fat. 45-minute sessions were performed with an 1-week interval. For efficacy evaluation, patient's abdominal circumferences and body weight were measured, and photographs were taken at baseline and each follow-up visit for 12 weeks. One subject was examined with computed tomography (CT) before the first session and six weeks after the first CT scan, and we measured the volume of subcutaneous fat layer. Any adverse effect was assessed during the entire study period. Reduction in abdominal circumferences was noted in most participants (10 of 12 patients). No serious adverse effect was reported. Volume reduction of abdominal subcutaneous fat layer was confirmed in a subject who took CT scan. Our study shows that the selective-field radiofrequency treatment seems to be safe and efficient for reduction of abdominal subcutaneous fat.

  12. Difficulties with access in percutaneous renal surgery

    PubMed Central

    Rais-Bahrami, Soroush; Friedlander, Justin I.; Duty, Brian D.; Okeke, Zeph; Smith, Arthur D.

    2011-01-01

    Percutaneous renal surgery provides a minimally invasive approach to the kidney for stone extraction in a number of different clinical scenarios. Certain clinical cases present inherent challenges to percutaneous access to the kidney. Herein, we present scenarios in which obtaining and/or maintaining percutaneous access is difficult along with techniques to overcome the challenges commonly encountered. Also, complications associated with these challenging percutaneous renal surgeries are discussed. PMID:21869906

  13. Percutaneous transbiliary biopsy.

    PubMed

    Andrade, Gustavo Vieira; Santos, Miguel Arcanjo; Meira, Marconi Roberto; Meira, Mateus Duarte

    2017-01-01

    Percutaneous drainage of the bile ducts is an established procedure for malignant obstructions, in which a histological diagnosis is often not obtained. We describe the biopsy technique of obstructive lesions through biliary drainage access, using a 7F endoscopic biopsy forceps, widely available; some are even reusable. This technique applies to lesions of the hepatic ducts, of the common hepatic duct and of all extension of the common bile duct. RESUMO A drenagem percutânea das vias biliares é um procedimento estabelecido para obstruções malignas, nos quais, muitas vezes, não se consegue um diagnóstico histológico. Descrevemos a técnica de biópsia da lesão obstrutiva através do acesso de drenagem biliar, utilizando um fórcipe de biópsia endoscópica 7F, amplamente disponível e alguns reutilizáveis. Esta técnica aplica-se a lesões dos ductos hepáticos, do hepático comum e de toda extensão do colédoco.

  14. Percutaneous renal tumour biopsy.

    PubMed

    Delahunt, Brett; Samaratunga, Hemamali; Martignoni, Guido; Srigley, John R; Evans, Andrew J; Brunelli, Matteo

    2014-09-01

    The use of percutaneous renal tumour biopsy (RTB) as a diagnostic tool for the histological characterization of renal masses has increased dramatically within the last 30 years. This increased utilization has paralleled advances in imaging techniques and an evolving knowledge of the clinical value of nephron sparing surgery. Improved biopsy techniques using image guidance, coupled with the use of smaller gauge needles has led to a decrease in complication rates. Reports from series containing a large number of cases have shown the non-diagnostic rate of RTB to range from 4% to 21%. Re-biopsy has been shown to reduce this rate, while the use of molecular markers further improves diagnostic sensitivity. In parallel with refinements of the biopsy procedure, there has been a rapid expansion in our understanding of the complexity of renal cell neoplasia. The 2013 Vancouver Classification is the current classification for renal tumours, and contains five additional entities recognized as novel forms of renal malignancy. The diagnosis of tumour morphotype on RTB is usually achievable on routine histology; however, immunohistochemical studies may be of assistance in difficult cases. The morphology of the main tumour subtypes, based upon the Vancouver Classification, is described and differentiating features are discussed. © 2014 John Wiley & Sons Ltd.

  15. Percutaneous absorption of urea.

    PubMed

    Ackermann, C; Flynn, G L; Wyk, C J

    1985-12-01

    Synopsis The effect of several variables on the in vitro permeation of urea through hairless mouse skin has been studied in order to determine the causes of an increasing permeability phenomenon found in studies with a range of hydrophilic compounds. The permeation of urea increased for a period of approximately 100 h after which a steady state permeation pattern was observed for approximately 25 h. Urea did not effect its own permeation in concentrations between 0.01 M and 1.67 M, and the same pattern of increasing permeation was followed in the presence of (N-morpholine)propanesulphonic acid and tris(hydroxyme)amino-methane buffers, as in the presence of normal saline. Urea did not affect the permeation of tritiated water. Methanol and water exhibited the same pattern of increasing permeation as urea. The continuously increasing permeation rate of urea up to 100 h is believed to be due to penetration and extensive association of water with the components of the stratum corneum, altering the ultra-structure of the stratum corneum and leading to the formation of large and extensive hydrophilic diffusion channels which do not exist in fresh, untreated skin. These presumed channels open the stratum corneum to facile permeation of highly polar substances such as urea. The physical events leading up to the ultra structural changes within the tissue at the microscopic level remain obscure and are the subject of ongoing research. L'absorption percutanée de l'urée.

  16. Effect of radiofrequency-generated thermal energy on the mechanical and histologic characteristics of the arterial wall in vivo: implications for radiofrequency angioplasty

    SciTech Connect

    Barry, K.J.; Kaplan, J.; Connolly, R.J.; Nardella, P.; Lee, B.I.; Becker, G.J.; Waller, B.F.; Callow, A.D.

    1989-02-01

    Abrupt reclosure of atherosclerotic vessels after percutaneous transluminal balloon angioplasty has been blamed on traumatic dissections and elastic recoil of the vessel wall. Thermal energy with compression produces fusion of separated arterial wall layers, and heat appears to alter the elastic recoil of the vessel wall. Radiofrequency (RF) thermal energy has been used to perform vascular anastomoses and thermal angioplasty. A simple in vivo experiment was designed to describe and quantitate vascular tissue weld strength produced by a range of RF thermal energy levels. Canine carotid arteries were compressed between a pair of modified bipolar forceps that applied RF energy, causing occlusive tissue welds between the apposed intimal surfaces. The strength of the welds was evaluated by measuring the perfusion pressure required to reopen the vessel lumen. A dosimetry range of 0 to 205 joules showed a typical dose-response curve for the relationship between energy applied and bond strength, plateauing at approximately 300 mm Hg. Light microscopy showed fusion of the inner surfaces of the vessel with preservation of vessel wall architecture. Additionally inflation of a bipolar RF balloon catheter in the normal canine carotid lumen produced an alteration of vessel profile angiographically and histologically. Results of these preliminary experiments suggest that balloon angioplasty with adjunctive RF thermal energy may have benefits in reducing the factors causing acute failure of conventional percutaneous transluminal balloon angioplasty.

  17. Percutaneous management of prosthetic valve thrombosis.

    PubMed

    Hariram, Vuppaladadhiam

    2014-01-01

    Thrombosis of a prosthetic valve is a serious complication in patients with prosthetic heart valves. Thrombolysis is the initial choice of treatment. Patients who do not respond to thrombolysis are subjected to surgery which carries a high risk. We report a case series of 5 patients with prosthetic mitral valve thrombosis who did not respond to thrombolysis and were subjected to percutaneous manipulation of the prosthetic valves successfully and improved. Five patients who were diagnosed to have prosthetic mitral valve thrombosis and failed to respond to a minimum of 36 h of thrombolysis (persistent symptoms with increased gradients, abnormal findings on fluoroscopy),were subjected to percutaneous treatment after receiving proper consent. None of them had a visible thrombus on transthoracic echocardiogram. All patients underwent transseptal puncture following which a 6F JR4 guiding catheter was passed into the left atrium. The valve leaflets were repeatedly hit gently under fluoroscopic guidance till they regained their normal mobility. Mean age was 38.8 years. Average peak and mean gradients prior to the procedure were 38 and 25 and after the procedure were 12 and 6 mm of Hg respectively. All patients had successful recovery of valve motion on fluoroscopy with normalization of gradients and complete resolution of symptoms. None of the patients had any focal neurological deficits, embolic manifestations or bleeding complications. Percutaneous manipulation of prosthetic valves in selected patients with prosthetic valve thrombosis who do not respond to thrombolytic therapy is feasible and can be used as an alternative to surgery. Copyright © 2014 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  18. Radiofrequency Ablation Beyond the Liver

    PubMed Central

    Neeman, Ziv; Wood, Bradford J.

    2008-01-01

    Radiofrequency ablation (RFA) has begun to show promise for extrahepatic indications. Although much of the reported work on image-guided RFA of liver neoplasms is quite promising, it is even earlier in the evaluation and validation process for extrahepatic RFA, with few short-term and no long-term studies reported. Although there are much more data for liver RFA with almost 3,000 cases reported in the literature, there are a number of ongoing investigations of RFA for tumors in the kidney, lung, bone, breast, bone, and adrenal gland. Debulking and pain control with RFA present palliative options becoming increasingly popular weapons in the interventionalist's oncology arsenal. Metastatic disease with a wide variety of primary histologies in a myriad of locations may be treated with RFA after a careful consideration of the risk-to-benefit ratio balance. The RFA technique can be slightly different outside the liver. Specifically, differing dielectric tissue characteristics may markedly alter the RFA treatment. Each different RFA system has a unique risk and advantage profile. Extrahepatic indications and contraindications will be suggested. Treatment tips and the unique complications and considerations will be introduced for some of the more common extrahepatic locations. PMID:12524646

  19. Radiofrequency-assisted liver resection.

    PubMed

    Delis, Spiros G; Bakoyiannis, Andreas; Tassopoulos, Nikos; Athanasiou, Kostas; Madariaga, Juan; Dervenis, Christos

    2008-08-01

    Surgical resection remains the treatment of choice for primary, secondary liver cancer and a number of benign liver lesions. Complications are mainly related to blood loss. Radiofrequency-assisted liver resection (RF-LR) has been proposed in order to achieve minimal blood loss during parenchymal transection. Between May 2005 and April 2007, 46 consecutive patients with various hepatic lesions underwent RF-LR using Radionics, Cool-Tip System. There were 28 men and 18 women with median age 65 years (range 54-76 years). Twelve major and 34 minor hepatectomies were performed for various diseases: hepatocellular carcinoma (n=19), metastatic carcinoma (n=23), focal nodal hyperplasia (n=2) and intrahepatic cholangiocarcinoma (ICC) (n=2). Hepatic inflow occlusion was not used. No perioperative death was documented. Median blood loss was 100ml (range 30-300cm(3)). Blood transfusion was required postoperatively in one patient. Median transection time was 35min (15-60min). Three patients developed biliary fistulas, four patients pleural effusions, one patient hyperbilirubinemia, two pneumonia and four wound infection. The median postoperative hospital stay was 6 days (range 4-10 days). In a median 12 month follow-up (range 3-24 months), four patients with colorectal metastases (CRM) and one patient with ICC developed recurrence. Cool-Tip RF device provides a unique, simple and safe method of bloodless liver resections and is indicated in cirrhotic patients with challenging hepatectomies (segment VIII, central resections).

  20. The radiofrequency magnetic dipole discharge

    NASA Astrophysics Data System (ADS)

    Martines, E.; Zuin, M.; Marcante, M.; Cavazzana, R.; Fassina, A.; Spolaore, M.

    2016-05-01

    This paper describes a novel and simple concept of plasma source, which is able to produce a radiofrequency magnetized discharge with minimal power requirements. The source is based on the magnetron concept and uses a permanent magnet as an active electrode. The dipolar field produced by the magnet confines the electrons, which cause further ionization, thus producing a toroidally shaped plasma in the equatorial region around the electrode. A plasma can be ignited with such scheme with power levels as low as 5 W. Paschen curves have been built for four different working gases, showing that in Helium or Neon, plasma breakdown is easily obtained also at atmospheric pressure. The plasma properties have been measured using a balanced Langmuir probe, showing that the electron temperature is around 3-4 eV and higher in the cathode proximity. Plasma densities of the order of 1016 m-3 have been obtained, with a good positive scaling with applied power. Overall, the electron pressure appears to be strongly correlated with the magnetic field magnitude in the measurement point.

  1. The radiofrequency magnetic dipole discharge

    SciTech Connect

    Martines, E. Zuin, M.; Cavazzana, R.; Fassina, A.; Spolaore, M.; Marcante, M.

    2016-05-15

    This paper describes a novel and simple concept of plasma source, which is able to produce a radiofrequency magnetized discharge with minimal power requirements. The source is based on the magnetron concept and uses a permanent magnet as an active electrode. The dipolar field produced by the magnet confines the electrons, which cause further ionization, thus producing a toroidally shaped plasma in the equatorial region around the electrode. A plasma can be ignited with such scheme with power levels as low as 5 W. Paschen curves have been built for four different working gases, showing that in Helium or Neon, plasma breakdown is easily obtained also at atmospheric pressure. The plasma properties have been measured using a balanced Langmuir probe, showing that the electron temperature is around 3–4 eV and higher in the cathode proximity. Plasma densities of the order of 10{sup 16 }m{sup −3} have been obtained, with a good positive scaling with applied power. Overall, the electron pressure appears to be strongly correlated with the magnetic field magnitude in the measurement point.

  2. 21 CFR 882.4725 - Radiofrequency lesion probe.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... (a) Identification. A radiofrequency lesion probe is a device connected to a radiofrequency (RF) lesion generator to deliver the RF energy to the site within the nervous system where a lesion is...

  3. 21 CFR 882.4725 - Radiofrequency lesion probe.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... (a) Identification. A radiofrequency lesion probe is a device connected to a radiofrequency (RF) lesion generator to deliver the RF energy to the site within the nervous system where a lesion is...

  4. 21 CFR 882.4725 - Radiofrequency lesion probe.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... (a) Identification. A radiofrequency lesion probe is a device connected to a radiofrequency (RF) lesion generator to deliver the RF energy to the site within the nervous system where a lesion is...

  5. 21 CFR 882.4725 - Radiofrequency lesion probe.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... (a) Identification. A radiofrequency lesion probe is a device connected to a radiofrequency (RF) lesion generator to deliver the RF energy to the site within the nervous system where a lesion is...

  6. 21 CFR 882.4725 - Radiofrequency lesion probe.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... (a) Identification. A radiofrequency lesion probe is a device connected to a radiofrequency (RF) lesion generator to deliver the RF energy to the site within the nervous system where a lesion is...

  7. A survey on monopolar radiofrequency treatment.

    PubMed

    Suh, Dong Hye; Hong, Eun Sun; Kim, Hyun Joo; Lee, Sang Jun; Kim, Hei Sung

    2017-08-14

    This questionnaire-based study was aimed to measure the level of appreciation, awareness of the special tips, and practice patterns of monopolar radiofrequency among Korean dermatologists practicing a specific monopolar radiofrequency device (Thermage® Inc., Hayward, CA). A total of 82 surveys were analyzed to show that the majority of participants (78.8%) were highly satisfied with the outcomes of monopolar radiofrequency treatment. All respondents were aware of the Eye Tip 0.25 cm(2) , and the majority knew the difference between the Face tip (blue) and the Total tip (orange). Most (86.3%) agreed to the statement that 900 shots were appropriate for facial tightening in those between the ages of 35 and 65 years. 66.2% of participants reported to have perform monopolar radiofrequency to extra-facial sites within the past year. As for the tips, the Total tip was most popular for all body sties and the Big tip was favored for the abdomen, thighs and buttock. We hope our data allow dermatologists to better utilize monopolar radiofrequency. © 2017 Wiley Periodicals, Inc.

  8. Percutaneous Hindfoot and Midfoot Fusion.

    PubMed

    Bauer, Thomas

    2016-09-01

    Hindfoot and midfoot fusions can be performed with percutaneous techniques. Preliminary results of these procedures are encouraging because they provide similar results than those obtained with open techniques with less morbidity and quick recovery. The best indications are probably fusions for mild-to-moderate reducible hindfoot and midfoot deformities in fragile patients with general or local bad conditions. The main limit is linked to the surgeon's experience in percutaneous foot surgery because a learning curve with the specific tools is necessary before doing these procedures.

  9. Nasal obstruction: comparison of radiofrequency with lateral displacement of the inferior turbinate and radiofrequency alone.

    PubMed

    Kaymakçi, Mustafa; Gur, Ozer Erdem; Ozdem, Cafer

    2014-01-01

    To compare the outcomes of the nasal obstruction, the main symptom of the patients who underwent radiofrequency and lateral displacement of the inferior turbinate and patients who were treated with radiofrequency alone. The prospective randomised study was conducted at the Department of Otorhinolaryngology and Head-Neck Surgery, Balikesir University Medical School, Balikesir, Turkey, between July and December 2012. It included 60 patients, diagnosed with allergic or non-allergic chronic rhinitis with inferior turbinate hypertrophy which was refractory to medical therapy. Half of the patients were treated with radiofrequency, and the rest with radiofrequency and lateral displacement. The main symptom of the patients was nasal obstruction. The frequency and degree of nasal obstruction were evaluated by patients' self-assessments using the standard 10-cm visual analogue scale. The evaluations were performed first pre-operatively and on the 1st, 3rd, 5th and 7th days postoperatively as well as at the end of the 4th week. SPSS 18 was used for statistical analysis. Nasal obstruction frequency and severity scores in patients treated with both radiofrequency and lateral displacement on post-operative days 3, 5 and 7 were found to be significantly lower (p<0.001) compared to the patients treated with only radiofrequency. The study demonstrated that radiofrequency and lateral displacement together is an effective method to prevent inferior turbinate oedema in the early post-operative period.

  10. Dexmedetomidine sedation for transesophageal echocardiography during percutaneous atrial septal defect closure in adult

    PubMed Central

    Jung, Jae Wook; Cheol Go, Gwang; Jeon, Sang Yoon; Bang, Sira; Lee, Ki Hwa; Kim, Yong Han; Kim, Dong-Kie

    2013-01-01

    Atrial septal defect (ASD) is second common congenital heart disease that often leads to adult period. Intracardiac or transesophageal echocardiography (TEE) is essential for percutaneous closure of ASD using Amplatzer septal occluder. Dexmedetomidine (DEX), which is a highly selective α2-agonist, has sedative and analgesic properties without respiratory depression in the clinical dose range. We report percutaneous closure of ASD with TEE under DEX sedation. PMID:24550975

  11. Percutaneous vertebroplasty: the follow-up.

    PubMed

    Barbero, S; Casorzo, I; Durando, M; Mattone, G; Tappero, C; Venturi, C; Gandini, G

    2008-02-01

    This article reports on our experience treating vertebral fractures with percutaneous vertebroplasty. A clinical and imaging follow-up designed to identify the early (especially pulmonary embolism of bone cement) and late complications of the technique is proposed. On the basis of the current guidelines, 101 patients were selected: 64 osteoporotic and 37 neoplastic. A total of 173 vertebrae were treated. Procedures were performed with both computed tomography and fluoroscopic guidance. Residual pain was evaluated with a visual analogue scale score immediately after vertebroplasty and 1, 15, 30, 90, 180 and 270 days later. Spine and chest radiographs were obtained 24 h after vertebroplasty; spine radiography was repeated 30 days later. Therapeutic success was obtained in 88% of osteoporotic patients and in 84% of neoplastic patients. Pulmonary cement emboli were identified in four patients, all of whom were asymptomatic. Percutaneous vertebroplasty is a safe and effective technique for the treatment of osteoporotic and neoplastic vertebral fractures. Clinical and imaging followup allows effective patient monitoring and early detection of possible complications.

  12. 47 CFR 2.801 - Radiofrequency device defined.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Radiofrequency device defined. 2.801 Section 2.801 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS Marketing of Radio-frequency Devices § 2.801 Radiofrequency...

  13. 47 CFR 2.801 - Radiofrequency device defined.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Radiofrequency device defined. 2.801 Section 2.801 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS Marketing of Radio-frequency Devices § 2.801 Radiofrequency...

  14. 47 CFR 2.801 - Radiofrequency device defined.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Radiofrequency device defined. 2.801 Section 2.801 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS Marketing of Radio-frequency Devices § 2.801 Radiofrequency...

  15. 47 CFR 2.801 - Radiofrequency device defined.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Radiofrequency device defined. 2.801 Section 2.801 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS Marketing of Radio-frequency Devices § 2.801 Radiofrequency...

  16. 47 CFR 2.801 - Radiofrequency device defined.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Radiofrequency device defined. 2.801 Section 2.801 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS Marketing of Radio-frequency Devices § 2.801 Radiofrequency...

  17. 47 CFR 1.1310 - Radiofrequency radiation exposure limits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Radiofrequency radiation exposure limits. 1... Radiofrequency radiation exposure limits. (a) Specific absorption rate (SAR) shall be used to evaluate the environmental impact of human exposure to radiofrequency (RF) radiation as specified in § 1.1307(b) within...

  18. 47 CFR 1.1310 - Radiofrequency radiation exposure limits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Radiofrequency radiation exposure limits. 1... Procedures Implementing the National Environmental Policy Act of 1969 § 1.1310 Radiofrequency radiation... exposure to radiofrequency (RF) radiation as specified in § 1.1307(b), except in the case of...

  19. 47 CFR 1.1310 - Radiofrequency radiation exposure limits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Radiofrequency radiation exposure limits. 1... Radiofrequency radiation exposure limits. (a) Specific absorption rate (SAR) shall be used to evaluate the environmental impact of human exposure to radiofrequency (RF) radiation as specified in § 1.1307(b) within...

  20. 47 CFR 1.1310 - Radiofrequency radiation exposure limits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Radiofrequency radiation exposure limits. 1... Radiofrequency radiation exposure limits. The criteria listed in table 1 shall be used to evaluate the environmental impact of human exposure to radiofrequency (RF) radiation as specified in § 1.1307(b), except...

  1. Renal Tumors: Technical Success and Early Clinical Experience with Radiofrequency Ablation of 18 Tumors

    SciTech Connect

    Sabharwal, Rohan Vladica, Philip

    2006-04-15

    Purpose. To evaluate the feasibility, safety, and technical efficacy of image-guided radiofrequency ablation (RFA) for the treatment of small peripheral renal tumors and to report our early results with this treatment modality. Methods. Twenty-two RFA sessions for 18 tumors were performed in 11 patients with renal tumors. Indications included coexistent morbidity, high surgical or anesthetic risk, solitary kidney, and hereditary predisposition to renal cell carcinoma. Ten patients had CT-guided percutaneous RFA performed on an outpatient basis. One patient had open intraoperative ultrasound-guided RFA. Technical success was defined as elimination of areas that enhanced at imaging within the entire tumor. With the exception of one patient with renal insufficiency who required gadolinium-enhanced MRI, the remaining patients underwent contrast-enhanced CT for post-treatment follow-up assessment. Follow-up was performed after 2-4 weeks and then at 3, 6, 12 months, and every 12 months thereafter. Results. Fourteen (78%) of 18 tumors were successfully ablated with one session. Three of the remaining four tumors required two sessions for successful ablation. One tumor will require a third session for areas of persistent enhancement. Mean patient age was 72.82 {+-} 10.43 years. Mean tumor size was 1.95 {+-} 0.79 cm. Mean follow-up time was 10.91 months. All procedures were performed without any major complications. Conclusions. Our early experience with percutaneous image-guided radiofrequency ablation demonstrates it to be a feasible, safe, noninvasive, and effective treatment of small peripheral renal tumors.

  2. Survival after Radiofrequency Ablation in 122 Patients with Inoperable Colorectal Lung Metastases

    SciTech Connect

    Gillams, Alice; Khan, Zahid; Osborn, Peter; Lees, William

    2013-06-15

    Purpose. To analyze the factors associated with favorable survival in patients with inoperable colorectal lung metastases treated with percutaneous image-guided radiofrequency ablation. Methods. Between 2002 and 2011, a total of 398 metastases were ablated in 122 patients (87 male, median age 68 years, range 29-90 years) at 256 procedures. Percutaneous CT-guided cool-tip radiofrequency ablation was performed under sedation/general anesthesia. Maximum tumor size, number of tumors ablated, number of procedures, concurrent/prior liver ablation, previous liver or lung resection, systemic chemotherapy, disease-free interval from primary resection to lung metastasis, and survival from first ablation were recorded prospectively. Kaplan-Meier analysis was performed, and factors were compared by log rank test. Results. The initial number of metastases ablated was 2.3 (range 1-8); the total number was 3.3 (range 1-15). The maximum tumor diameter was 1.7 (range 0.5-4) cm, and the number of procedures was 2 (range 1-10). The major complication rate was 3.9 %. Overall median and 3-year survival rate were 41 months and 57 %. Survival was better in patients with smaller tumors-a median of 51 months, with 3-year survival of 64 % for tumors 2 cm or smaller versus 31 months and 44 % for tumors 2.1-4 cm (p = 0.08). The number of metastases ablated and whether the tumors were unilateral or bilateral did not affect survival. The presence of treated liver metastases, systemic chemotherapy, or prior lung resection did not affect survival. Conclusion. Three-year survival of 57 % in patients with inoperable colorectal lung metastases is better than would be expected with chemotherapy alone. Patients with inoperable but small-volume colorectal lung metastases should be referred for ablation.

  3. Radiofrequency uvulopalatoplasty for primary snoring.

    PubMed

    Samimi Ardestani, Seyed Hadi; Dadgarnia, Mohammad Hossein; Baradaranfar, Mohammad Hossein; Mazidi, Mona; Rabbani, Mahtab; Behniafard, Nasim; Baradaranfar, Amin

    2013-09-09

    Simple snoring is a social problem, one that can gravely affect the patient's married life. About 40% of men and 20% of women are affected, and it often goes along with sleep-disordered breathing. Up to now various surgical techniques have been defined such as UPPP(uvulopalatopharyngo plasty), and laser-assisted uvulopalatoplasty (LAUP). Among the surgical methods, RAUP (radiofrequency assisted uvulopalatoplasty) is a minimal invasive, an easy performed, and time and cost effective one. We designed a before and after a clinical trial. The inclusion criteria were age >18 years, complaint of nocturnal snoring, have a bed partner to assess snoring, AHI<5 events per hour in the polysomnography, malampathy score (soft palate position) I or II, an elongated uvula, grade I and II of pharyngeal webbing and patient consent was needed too. A 10-score visual analog scale (VAS) of snoring severity was completed by bed partner. All of 35 included patients underwent RAUP under local anesthesia by the same expert surgeon. After 3 months, 6 months and one year, subjective snoring decreased significantly compared to the preoperative period. The decline in VAS in 6 month compared to 3 months postoperatively, was not significant (P=0.223). When comparing 1 year and 6 months after treatment, the VAS scores were increased, but they were not significant (From 1.8 to 1.9, P=0.78). Three months after treatment minor complications consisted of: nasal regurgitation in 2 patients (5.7%), nasal speech in 2 (5.7%) and exacerbation of snoring in 2 (5.7%) patients.There was no major complication including mucosal laceration, uvular damage and obstruction of the airway. The rate of snoring decrease did not correlate with age, sex and BMI. Based on this study and literature review, it seems RAUP is a safe surgery, which may decrease symptoms of snoring, at least, in short-term follow-up.

  4. Radiofrequency Cauterization with Biopsy Introducer Needle

    PubMed Central

    Pritchard, William F.; Wray-Cahen, Diane; Karanian, John W.; Hilbert, Stephen; Wood, Bradford J.

    2014-01-01

    PURPOSE The principal risks of needle biopsy are hemorrhage and implantation of tumor cells in the needle tract. This study compared hemorrhage after liver and kidney biopsy with and without radiofrequency (RF) ablation of the needle tract. MATERIALS AND METHODS Biopsies of liver and kidney were performed in swine through introducer needles modified to allow RF ablation with the distal 2 cm of the needle. After each biopsy, randomization determined whether the site was to undergo RF ablation during withdrawal of the introducer needle. Temperature was measured with a thermistor stylet near the needle tip, with a target temperature of 70°C–100°C with RF ablation. Blood loss was measured as grams of blood absorbed in gauze at the puncture site for 2 minutes after needle withdrawal. Selected specimens were cut for gross examination. RESULTS RF ablation reduced bleeding compared with absence of RF ablation in liver and kidney (P < .01), with mean blood loss reduced 63% and 97%, respectively. Mean amounts of blood loss (±SD) in the liver in the RF and no-RF groups were 2.03 g ± 4.03 (CI, 0.53–3.54 g) and 5.50 g ± 5.58 (CI, 3.33–7.66 g), respectively. Mean amounts of blood loss in the kidney in the RF and no-RF groups were 0.26 g ± 0.32 (CI, −0.01 to 0.53 g) and 8.79 g ± 7.72 (CI, 2.34–15.24 g), respectively. With RF ablation, thermal coagulation of the tissue surrounding the needle tract was observed. CONCLUSION RF ablation of needle biopsy tracts reduced hemorrhage after biopsy in the liver and kidney and may reduce complications of hemorrhage as well as implantation of tumor cells in the tract. PMID:14963187

  5. PAIR as percutaneous treatment of hydatid liver cysts.

    PubMed

    Peláez, V; Kugler, C; Correa, D; Del Carpio, M; Guangiroli, M; Molina, J; Marcos, B; Lopez, E

    2000-03-25

    Hydatid disease of the liver remains an important and challenging problem in rural areas; although, surgery is considered the treatment of choice, percutaneous treatment of hydatid cysts is relatively new, and the data related to it are limited. The purpose of the study was to present the results of percutaneous treatment of liver hydatid cysts. Thirty-four patients (13 male and 21 female), ranging in age between 14 and 80 years, with 55 liver hydatid cysts underwent percutaneous treatment with albendazole prophylaxis. Cysts were treated with a one-stage procedure that consisted of puncture of the cysts under guidance with computed tomography, aspiration of fluid, injection of hypertonic saline solution as scolicidal agent and reaspiration. Follow-up examinations showed progressive reduction and solidification of the cysts. The mean reduction in volume was 72%. No mortality, abdominal dissemination, or tract seeding occurred. Minor complications were urticaria with pruritus in two patients. One patient had a subcapusular hematoma without problem. Hospitalization courses varied from ambulatory procedures to 15 days of in-patient, mean hospital stay was 1.82 days. The results of percutaneous liver hydatid cyst treatment, indicating that the procedure is efficient and safe and offers complete cure in selected patients with a short hospitalization and that this technique should be considered an alternative to surgery.

  6. The value of percutaneous cholangiography

    PubMed Central

    Evison, Gordon; McNulty, Myles; Thomson, Colin

    1973-01-01

    Percutaneous cholangiograms performed on fifty patients in a district general hospital have been reviewed, and the advantages and limitations of the examination are described. The investigation is considered to have sufficient diagnostic value to warrant its inclusion in the diagnostic armamentarium of every general radiological department. ImagesFig. 1Fig. 2Fig. 3Fig. 4 PMID:4788917

  7. Image guided percutaneous splenic interventions.

    PubMed

    Kang, Mandeep; Kalra, Naveen; Gulati, Madhu; Lal, Anupam; Kochhar, Rohit; Rajwanshi, Arvind

    2007-10-01

    The objective of this study is to evaluate the efficacy and safety of image-guided percutaneous splenic interventions as diagnostic or therapeutic procedures. We performed a retrospective review of our interventional records from July 2001 to June 2006. Ninety-five image-guided percutaneous splenic interventions were performed after informed consent in 89 patients: 64 men and 25 women who ranged in age from 5 months to 71 years (mean, 38.4 years) under ultrasound (n=93) or CT (n=2) guidance. The procedures performed were fine needle aspiration biopsy of focal splenic lesions (n=78) and aspiration (n=10) or percutaneous catheter drainage of a splenic abscess (n=7). Splenic fine needle aspiration biopsy was successful in 62 (83.78%) of 74 patients with benign lesions diagnosed in 43 (58.1%) and malignancy in 19 (25.67%) patients. The most common pathologies included tuberculosis (26 patients, 35.13%) and lymphoma (14 patients, 18.91%). Therapeutic aspiration or pigtail catheter drainage was successful in all (100%) patients. There were no major complications. Image-guided splenic fine needle aspiration biopsy is a safe and accurate technique that can provide a definitive diagnosis in most patients with focal lesions in the spleen. This study also suggests that image-guided percutaneous aspiration or catheter drainage of splenic abscesses is a safe and effective alternative to surgery.

  8. Radio-frequency characteristics of graphene oxide

    NASA Astrophysics Data System (ADS)

    Kim, Whan Kyun; Jung, Young Mo; Cho, Joon Hyong; Kang, Ji Yoong; Oh, Ju Yeong; Kang, Hosung; Lee, Hee-Jo; Kim, Jae Hun; Lee, Seok; Shin, H. J.; Choi, J. Y.; Lee, S. Y.; Kim, Y. C.; Han, I. T.; Kim, J. M.; Yook, Jong-Gwan; Baik, Seunghyun; Jun, Seong Chan

    2010-11-01

    We confirm graphene oxide, a two-dimensional carbon structure at the nanoscale level can be a strong candidate for high-efficient interconnector in radio-frequency range. In this paper, we investigate high frequency characteristics of graphene oxide in range of 0.5-40 GHz. Radio-frequency transmission properties were extracted as S-parameters to determine the intrinsic ac transmission of graphene sheets, such as the impedance variation dependence on frequency. The impedance and resistance of graphene sheets drastically decrease as frequency increases. This result confirms graphene oxide has high potential for transmitting signals at gigahertz ranges.

  9. Complications of percutaneous vertebroplasty

    PubMed Central

    Saracen, Agnieszka; Kotwica, Zbigniew

    2016-01-01

    Abstract Percutaneous vertebroplasty (PVP) is a minimally invasive procedure widely used for the treatment of pain due to vertebral fractures of different origins—osteoporotic, traumatic, or neoplastic. PVP is minimally invasive, but the complications are not rare; however, they are in most cases not significant clinically. The most frequent is cement leakage, which can occur onto veins, paravertebral soft tissue, into the intervertebral disk, or to the spinal canal, affecting foraminal area or epidural space. We analyzed results of treatment and complications of vertebroplasty performed with the use of polimethylomethylacrylate cement (PMMA) on 1100 vertebrae, with a special regard to the severity of complication and eventual clinical manifestation. One thousand one hundred PVP were analyzed, performed in 616 patients. There were 468 (76%) women and 148 men (24%), 24 to 94-year old, mean age 68 years. From 1100 procedures, 794 treated osteporotic and 137 fractures due to malignant disease, 69 PVP were made in traumatic fractures. One hundred patients had painful vertebral hemangiomas. Seven hundred twenty-six (66%) lesions were in thoracic, and 374 (34%) in lumbar area. Results of treatment were assessed using 10 cm Visual Analogue Scale (VAS) 12 hours after surgery, 7 days, 30 days, and then each 6 months, up to 3 years. Before surgery all patients had significant pain 7 to 10 in VAS scale, mean 8.9 cm. Twelve  hours after surgery 602 (97.7%) reported significant relief of pain, with mean VAS of 2,3 cm. Local complications occurred in 50% of osteoporotic, 34% of neoplastic, 16% of traumatic fractures, and 2% of vertebral hemangiomas. The most common was PMMA leakage into surrounding tissues—20%; paravertebral vein embolism—13%; intradiscal leakage—8%; and PMMA leakage into the spinal canal—0.8%. Results of treatment did not differ between patients with and without any complications. From 104 patients who had chest X-ray or CT study performed

  10. CT-guided radiofrequency ablation in patients with hepatic metastases from breast cancer.

    PubMed

    Jakobs, Tobias F; Hoffmann, Ralf-Thorsten; Schrader, Angelika; Stemmler, Hans Joachim; Trumm, Christoph; Lubienski, Andreas; Murthy, Ravi; Helmberger, Thomas K; Reiser, Maximilian F

    2009-01-01

    The purpose of this study was to evaluate technical success, technique effectiveness, and survival following radiofrequency ablation for breast cancer liver metastases and to determine prognostic factors. Forty-three patients with 111 breast cancer liver metastases underwent CT-guided percutaneous radiofrequency (RF) ablation. Technical success and technique effectiveness was evaluated by performing serial CT scans. We assessed the prognostic value of hormone receptor status, overexpression of human epidermal growth factor receptor 2 (HER2), and presence of extrahepatic tumor spread. Survival rates were calculated using the Kaplan-Meier method. Technical success was achieved in 107 metastases (96%). Primary technique effectiveness was 96%. During follow-up local tumor progression was observed in 15 metastases, representing a secondary technique effectiveness of 86.5%. The overall time to progression to the liver was 10.5 months. The estimated overall median survival was 58.6 months. There was no significant difference in terms of survival probability with respect to hormone receptor status, HER2 overexpression, and presence of isolated bone metastases. Survival was significantly lower among patients with extrahepatic disease, with the exception of skeletal metastases. We conclude that CT-guided RF ablation of liver metastases from breast cancer can be performed with a high degree of technical success and technique effectiveness, providing promising survival rates in patients with no visceral extrahepatic disease. Solitary bone metastases did not negatively affect survival probability after RF ablation.

  11. CT-Guided Radiofrequency Ablation in Patients with Hepatic Metastases from Breast Cancer

    SciTech Connect

    Jakobs, Tobias F. Hoffmann, Ralf-Thorsten; Schrader, Angelika; Stemmler, Hans Joachim; Trumm, Christoph; Lubienski, Andreas; Murthy, Ravi; Helmberger, Thomas K.; Reiser, Maximilian F.

    2009-01-15

    The purpose of this study was to evaluate technical success, technique effectiveness, and survival following radiofrequency ablation for breast cancer liver metastases and to determine prognostic factors. Forty-three patients with 111 breast cancer liver metastases underwent CT-guided percutaneous radiofrequency (RF) ablation. Technical success and technique effectiveness was evaluated by performing serial CT scans. We assessed the prognostic value of hormone receptor status, overexpression of human epidermal growth factor receptor 2 (HER2), and presence of extrahepatic tumor spread. Survival rates were calculated using the Kaplan-Meier method. Technical success was achieved in 107 metastases (96%). Primary technique effectiveness was 96%. During follow-up local tumor progression was observed in 15 metastases, representing a secondary technique effectiveness of 86.5%. The overall time to progression to the liver was 10.5 months. The estimated overall median survival was 58.6 months. There was no significant difference in terms of survival probability with respect to hormone receptor status, HER2 overexpression, and presence of isolated bone metastases. Survival was significantly lower among patients with extrahepatic disease, with the exception of skeletal metastases. We conclude that CT-guided RF ablation of liver metastases from breast cancer can be performed with a high degree of technical success and technique effectiveness, providing promising survival rates in patients with no visceral extrahepatic disease. Solitary bone metastases did not negatively affect survival probability after RF ablation.

  12. Fluoroscopy-guided Bipolar Radiofrequency Thermocoagulation Treatment for Discogenic Low Back Pain

    PubMed Central

    Zhang, Li; Ding, Xin-Li; Zhao, Xu-Li; Wang, Jun-Nan; Li, Yan-Ping; Tian, Ming

    2016-01-01

    Background: The efficacy of percutaneous intradiscal radiofrequency thermocoagulation (PIRFT) for the treatment of discogenic low back pain (LBP) remains controversial. However, all the PIRFT studies utilized monopolar radiofrequency thermocoagulation (RFTC). The aim of this study was to investigate the safety and efficacy of bipolar RFTC for the treatment of discogenic LBP. Methods: A total of 23 patients with discogenic LBP were treated with single-level bipolar RFTC. The patients were assessed before the procedure and at 1 week, 1 month, 3 months, 6 months, and 1 year after the procedure. The primary outcome included the visual analog scale (VAS) score and the Oswestry Disability Index (ODI) score. The secondary outcome included pain relief, reduction of analgesic dose, and patient satisfaction. Results: The VAS and ODI scores were significantly decreased after bipolar RFTC treatment at all time points of follow-up (P < 0.05). Bipolar RFTC treatment also resulted in a significant change in all secondary measures, such as pain relief, reduction of analgesic dose, and patient satisfaction. No serious complications or neurological sequelae were observed in any of the patients. Conclusions: Bipolar RFTC treatment can significantly attenuate pain and improve the function of patients with discogenic LBP. PMID:27647190

  13. Comprehensive thermoregulation for the purpose of skin tightening using a novel radiofrequency treatment device: a preliminary report.

    PubMed

    Key, Douglas J

    2014-02-01

    Radiofrequency-induced heating of dermal and subdermal tissue promotes skin contracture; however, the temperature threshold for inducing an epidermal burn is lower than the therapeutic temperature thresholds required for collagen remodeling, and therefore, there is the possibility of epidermal burn. Herein, we evaluate a radiofrequency treatment that provides novel real-time subdermal and epidermal temperature monitoring. A retrospective chart review of 18 subjects undergoing thermistor-controlled subdermal skin tightening via percutaneous radiofrequency was conducted. During the treatment, epidermal temperature was concurrently monitored by a handheld infrared laser thermometer and a forward looking infrared camera system and peak temperatures readings were reported and evaluated. Mean temperatures of 43.6 and 38.2°C were reported for the infrared camera and infrared thermometer. The Bland-Altman plot analysis reported a bias of 5.38°C and 95% limits of agreement between 0.60 and 10.15°C. Additionally, the mean difference or bias of 5.38°C was statistically significant (P<0.0001. Our preliminary data supports a superior form of thermoregulation for the purposes of skin tightening that integrates continuous subsurface and epidermal temperature monitoring.

  14. Real-time calibration of temperature estimates during radiofrequency ablation.

    PubMed

    Varghese, T; Daniels, M J

    2004-07-01

    Radiofrequency ablation is an interstitial focal ablative therapy that can be used in a percutaneous fashion and permits in situ destruction of hepatic tumors. Recurrence rates after rf therapy are as high as 34-55%, due to difficulties in accurately identifying the zone of necrosis (thermal lesion) because of the low intrinsic acoustic contrast between normal and ablated liver tissue. Our goal is to provide real-time ultrasonic tracking of temperature changes over the large range of temperatures traditionally used (40-100 degrees C) in rfablation procedures using an external ultrasound transducer. Temperature estimates are obtained using a cross-correlation algorithm applied to rf ultrasound echo signal data acquired at discrete intervals during heating. Apparent tissue displacement estimates obtained at these discrete time-intervals are accumulated to obtain a cumulative displacement map, whose gradient provides after appropriate scaling provides a temperature map at the specified elapsed ablation duration. Temperature maps are used to display the initial temperature rise and to continuously update a thermal map of the treated region. In this paper, we develop calibration curves that relate the echo shift due to the change in the speed of sound and thermal expansion to the corresponding temperature increase on in-vitro tissue specimens. These calibration curves can then be utilized for the real time calibration and analysis of temperature estimates obtained from the rf echo signals during ablation. Temperature maps obtained using the calibration curve compare favorably to temperature estimates observed using the invasive thermosensor readings on the ablation electrode and previous results that utilized a linear calibration factor.

  15. Rapid progression of hepatocellular carcinoma after Radiofrequency Ablation

    PubMed Central

    Ruzzenente, Andrea; de Manzoni, Giovanni; Molfetta, Matteo; Pachera, Silvia; Genco, Bruno; Donataccio, Matteo; Guglielmi, Alfredo

    2004-01-01

    AIM: To report the results of radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) in cirrhotic patients and to describe the treatment related complications (mainly the rapid intrahepatic neoplastic progression). METHODS: Eighty-seven consecutive cirrhotic patients with 104 HCC (mean diameter 3.9 cm, 1.3 SD) were submitted to RFA between January 1998 and June 2003. In all cases RFA was performed with percutaneous approach under ultrasound guidance using expandable electrode needles. Treatment efficacy (necrosis and recurrence) was estimated with dual phase computed tomography (CT) and alpha-fetoprotein (AFP) level. RESULTS: Complete necrosis rate after single or multiple treatment was 100%, 87.7% and 57.1% in HCC smaller than 3 cm, between 3 and 5 cm and larger than 5 cm respectively (P = 0.02). Seventeen lesions of 88(19.3%) developed local recurrence after complete necrosis during a mean follow up of 19.2 mo. There were no treatment-related deaths in 130 procedures and major complications occurred in 8 patients (6.1 %). In 4 patients, although complete local necrosis was achieved, we observed rapid intrahepatic neoplastic progression after treatment. Risk factors for rapid neoplastic progression were high preoperative AFP values and location of the tumor near segmental portal branches. CONCLUSION: RFA is an effective treatment for hepatocellular carcinoma smaller than 5 cm with complete necrosis in more than 80% of lesions. Patients with elevated AFP levels and tumors located near the main portal branch are at risk for rapid neoplastic progression after RFA. Further studies are necessary to evaluate the incidence and pathogenesis of this underestimated complication. PMID:15069713

  16. Radiofrequency balloon angioplasty. Rationale and proof of principle

    SciTech Connect

    Becker, G.J.; Lee, B.I.; Waller, B.F.; Barry, K.J.; Kaplan, J.; Connolly, R.; Dreesen, R.G.; Nardella, P.

    1988-11-01

    Post-angioplasty restenosis (PARS) in atherosclerotic lesions of medium and small arteries occurs in about one-third of cases in the first year following percutaneous transluminal angioplasty (PTA) (early PARS). PARS includes acute spasm, dissection with reclosure, elastic recoil, fibrocellular proliferative response, and progressive atheromatous disease. Fibrocellular proliferation (possibly initiated by platelet derived growth factor) is felt to be culpable in many cases of early PARS (months). Pharmacologic regimens, stents, and thermal welding of the intimal-medial cracks of PTA are among the interventions being developed to deal with PARS. Radiofrequency (RF) current as a source of thermal energy may be useful in combination with balloon angioplasty to reduce PARS. Ideally, this combination would (1) weld intimal-medial cracks of PTA; (2) mold plaque and normal vessel to increase lumen diameters without creating intimal-medial cracks; and (3) destroy medial smooth muscle cells and multipotential cells (cellular substrate of PARS). Canine in vivo studies have established the feasibility of RF-mediated vascular tissue welding. Human aortic specimens (N = 28) were manually dissected into intima-media and media-adventitia layers. Bipolar RF energy (650 KHz, total 300 J) and mechanical pressure (1 atm) (experimental group, N = 24) or mechanical pressure alone (control group, N = 4) were applied to the reapposed specimen layers in a special chamber. The chamber was modified with a bipolar electrode designed to reproduce that planned for an RF balloon angioplasty catheter. Welding was demonstrated in normal and atherosclerotic treated specimens (23/24 or 96%) but not controls (0/4).

  17. [Complications of fluoroscopy-, ultrasound-, and CT-guided percutaneous interventional procedures].

    PubMed

    Dupas, B; Frampas, E; Leaute, F; Bertrand-Vasseur, A; Lerat, F

    2005-05-01

    The purpose of this article is to describe potential complications following the most common image-guided (fluoroscopy, ultrasound or CT) percutaneous interventional procedures, both diagnostic and therapeutic, thoraco-abdominal and musculoskeletal, as well as to review risk factors and the best practice recommendations. Prior to any interventional procedure, it is necessary to ascertain the absence of any abnormality in coagulation, to secure enough time to explain the procedure to the patient, and to adhere to strict sterile technique. Indeed, infections and hemorrhagic complications are the principal causes of mortality and morbidity for all procedures. Following lung biopsy, CT scan detects an immediate pneumothorax in 30% of patients. Major complications following percutaneous liver biopsy occur within 3 to 6 hours. Following a percutaneous drainage, complications occur in less than 10% of cases. Following a radiofrequency thermal ablation of malignant tumors, the mortality rate is low (0,5 to 1,4%), infection and hemorrhage are the most frequent complications. While rare, septic arthritis is the main complication that can follow musculoskeletal procedures and is a cause of medical malpractice lawsuits brought by patients.

  18. Radiation Exposure During Percutaneous Ablation of Small Renal Masses: A Multi-Institutional Multimodality Analysis.

    PubMed

    Tracy, Chad Robert; Kogan, Paul; Gupta, Amit; Gahan, Jeffrey C; Theckumparampil, Nithin P J; Elsamra, Sammy E; Okunov, Zhamshid; Sun, Shiliang; Lall, Chandana; Lobko, Igor; Landman, Jaime; Cadeddu, Jeffrey A; Kavoussi, Louis R

    2015-11-01

    To understand the effective radiation dose during percutaneous cryoablation (CA) and radiofrequency ablation (RFA) and characterize variables that may affect the individual dose. The effective radiation dose was determined by conversion of the dose-length product from CT scans performed during percutaneous CA or RFA for patients with solitary renal masses (<4 cm) at four academic centers. Radiation dose per case was compared between patients and institutions using multivariate and univariate analysis. Lifetime attributable risk of cancer was calculated for each institution and utilized to determine the number needed to harm for a range of ages at the time of exposure. One hundred twenty-three patients met the inclusion criteria with a mean age of 71 years. Sixty-nine percent of patients were male, mean body-mass index (BMI) was 29.4, and mean tumor size was 2.2 cm. The mean effective radiation dose per ablation was 40 mSv (range 3.7-147). On multivariate analysis, only BMI and institution were associated with the radiation dose. No significant difference in radiation exposure was seen for RFA or CA procedures. Radiation exposure during percutaneous ablation is similar to a multiphase CT scan. However, there is wide variability in individual treatment exposure, varying from 3.7 to 147 mSv, depending primarily on institution and BMI. Standardization of protocols is required to achieve as low as reasonably achievable levels of radiation.

  19. Laser speckle imaging to improve clinical outcomes for patients with trigeminal neuralgia undergoing radiofrequency thermocoagulation.

    PubMed

    Ringkamp, Matthias; Wooten, Matthew; Carson, Benjamin S; Lim, Michael; Hartke, Timothy; Guarnieri, Michael

    2016-02-01

    Percutaneous treatments for trigeminal neuralgia are safe, simple, and effective for achieving good pain control. Procedural risks could be minimized by using noninvasive imaging techniques to improve the placement of the radiofrequency thermocoagulation probe into the trigeminal ganglion. Positioning of a probe is crucial to maximize pain relief and to minimize unwanted side effects, such as denervation in unaffected areas. This investigation examined the use of laser speckle imaging during probe placement in an animal model. This preclinical safety study used nonhuman primates, Macaca nemestrina (pigtail monkeys), to examine whether real-time imaging of blood flow in the face during the positioning of a coagulation probe could monitor the location and guide the positioning of the probe within the trigeminal ganglion. Data from 6 experiments in 3 pigtail monkeys support the hypothesis that laser imaging is safe and improves the accuracy of probe placement. Noninvasive laser speckle imaging can be performed safely in nonhuman primates. Because improved probe placement may reduce morbidity associated with percutaneous rhizotomies, efficacy trials of laser speckle imaging should be conducted in humans.

  20. Percutaneous Valvuloplasty for Bioprosthetic Tricuspid Valve Stenosis

    PubMed Central

    Malhotra, Rohit; Sharma, Anjali; Kakouros, Nikolaos

    2017-01-01

    Percutaneous transcatheter tricuspid balloon valvuloplasty (PTTBV) is an accepted treatment option for symptomatic severe native tricuspid valve stenosis, although surgical tricuspid valve replacement remains the treatment of choice. There have been few reports of successful PTTBV for bioprosthetic tricuspid valve stenosis. We present case reports of 3 patients from our hospital experience. Two of the 3 cases were successful, with lasting clinical improvement, whereas the 3rd patient failed to show a reduction in valve gradient. We describe the standard technique used for PTTBV. We present results from a literature review that identified 16 previously reported cases of PTTBV for bioprosthetic severe tricuspid stenosis, with overall favorable results. We conclude that PTTBV should perhaps be considered for a select patient population in which symptomatic improvement and hemodynamic stability are desired immediately, and particularly for patients who are inoperable or at high surgical risk. PMID:28265212

  1. Effect of radiofrequency radiation in cultured mammalian cells: A review.

    PubMed

    Manna, Debashri; Ghosh, Rita

    2016-01-01

    The use of mobile phone related technologies will continue to increase in the foreseeable future worldwide. This has drawn attention to the probable interaction of radiofrequency electromagnetic radiation with different biological targets. Studies have been conducted on various organisms to evaluate the alleged ill-effect on health. We have therefore attempted to review those work limited to in vitro cultured cells where irradiation conditions were well controlled. Different investigators have studied varied endpoints like DNA damage, cell cycle arrest, reactive oxygen species (ROS) formation, cellular morphology and viability to weigh the genotoxic effect of such radiation by utilizing different frequencies and dose rates under various irradiation conditions that include continuous or pulsed exposures and also amplitude- or frequency-modulated waves. Cells adapt to change in their intra and extracellular environment from different chemical and physical stimuli through organized alterations in gene or protein expression that result in the induction of stress responses. Many studies have focused on such effects for risk estimations. Though the effects of microwave radiation on cells are often not pronounced, some investigators have therefore combined radiofrequency radiation with other physical or chemical agents to observe whether the effects of such agents were augmented or not. Such reports in cultured cellular systems have also included in this review. The findings from different workers have revealed that, effects were dependent on cell type and the endpoint selection. However, contradictory findings were also observed in same cell types with same assay, in such cases the specific absorption rate (SAR) values were significant.

  2. Radiofrequency identification technology: protecting the drug supply.

    PubMed

    2005-01-01

    The FDA has stepped up its efforts to improve the safety and security of the nation's drug supply by encouraging the use of a state-of-the-art technology that tags product packaging electronically. The technology, called radiofrequency identification, or RFID, allows manufacturers and distributors to more precisely track drug products through the supply chain.

  3. Percutaneous tricuspid valve replacement in congenital and acquired heart disease.

    PubMed

    Roberts, Philip A; Boudjemline, Younes; Cheatham, John P; Eicken, Andreas; Ewert, Peter; McElhinney, Doff B; Hill, Sharon L; Berger, Felix; Khan, Danyal; Schranz, Dietmar; Hess, John; Ezekowitz, Michael D; Celermajer, David; Zahn, Evan

    2011-07-05

    This study sought to describe the first human series of percutaneous tricuspid valve replacements in patients with congenital or acquired tricuspid valve (TV) disease. Percutaneous transcatheter heart valve replacement of the ventriculoarterial (aortic, pulmonary) valves is established. Although there are isolated reports of transcatheter atrioventricular heart valve replacement (hybrid and percutaneous), this procedure has been less frequently described; we are aware of no series describing this procedure for TV disease. We approached institutions with significant experience with the Melody percutaneous pulmonary valve (Medtronic, Inc., Minneapolis, Minnesota) to collect data where this valve had been implanted in the tricuspid position. Clinical and procedural data were gathered for 15 patients. Indications for intervention included severe hemodynamic compromise and perceived high surgical risk; all had prior TV surgery and significant stenosis and/or regurgitation of a bioprosthetic TV or a right atrium-to-right ventricle conduit. Procedural success was achieved in all 15 patients. In patients with predominantly stenosis, mean tricuspid gradient was reduced from 12.9 to 3.9 mm Hg (p < 0.01). In all patients, tricuspid regurgitation was reduced to mild or none. New York Heart Association functional class improved in 12 patients. The only major procedural complication was of third-degree heart block requiring pacemaker insertion in 1 patient. One patient developed endocarditis 2 months after implant, and 1 patient with pre-procedural multiorgan failure did not improve and died 20 days after the procedure. The remaining patients have well-functioning Melody valves in the TV position a median of 4 months after implantation. In selected cases, patients with prior TV surgery may be candidates for percutaneous TV replacement. Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  4. CT evaluation pre- and post-percutaneous ablation by radiofrequency of osteoid osteoma. Preliminary experience.

    PubMed

    Martorano, D; Verna, V; Mancini, A; Mastrantuono, D; Faletti, C; Gino, G; Albertini, U; Mellano, D; Piana, R; Marone, S; Brach del Prever, E; Linari, A; Forni, M

    2003-01-01

    Evaluation of bone remanagement after treatment by thermoablation of osteoid osteoma (OO) by CT scan. Nine cases of OO (8 in the limbs, 1 in the pelvis) following biopsy were treated by CT-guided thermoablation. Clinical results, complications, density of tissues treated by CT scan (pre-postop, 6, 12 months) are evaluated. Absence of complications, regression of pain over 2 weeks, resumption of sports activity in 1 month. Bone density after treatment increases but even after 1 year it is much lower than normal levels. Bone remodeling after thermoablation of OO requires much time, the process is still visible 12 months later by CT scan. CT scan is an adequate method, not only for diagnosis and treatment, but also for follow-up, capable of evaluating in time the changes in density of the site of the lesion, which is useful for a comparison in case of postoperative pain of doubtful origin.

  5. Percutaneous Tumor Ablation Tools: Microwave, Radiofrequency, or Cryoablation—What Should You Use and Why?

    PubMed Central

    Lubner, Meghan G.; Ziemlewicz, Timothy J.; Lee, Fred T.; Brace, Christopher L.

    2014-01-01

    Image-guided thermal ablation is an evolving and growing treatment option for patients with malignant disease of multiple organ systems. Treatment indications have been expanding to include benign tumors as well. Specifically, the most prevalent indications to date have been in the liver (primary and metastatic disease, as well as benign tumors such as hemangiomas and adenomas), kidney (primarily renal cell carcinoma, but also benign tumors such as angiomyolipomas and oncocytomas), lung (primary and metastatic disease), and soft tissue and/or bone (primarily metastatic disease and osteoid osteomas). Each organ system has different underlying tissue characteristics, which can have profound effects on the resulting thermal changes and ablation zone. Understanding these issues is important for optimizing clinical results. In addition, thermal ablation technology has evolved rapidly during the past several decades, with substantial technical and procedural improvements that can help improve clinical outcomes and safety profiles. Staying up to date on these developments is challenging but critical because the physical properties underlying the different ablation modalities and the appropriate use of adjuncts will have a tremendous effect on treatment results. Ultimately, combining an understanding of the physical properties of the ablation modalities with an understanding of the thermal kinetics in tissue and using the most appropriate ablation modality for each patient are key to optimizing clinical outcomes. Suggested algorithms are described that will help physicians choose among the various ablation modalities for individual patients. ©RSNA, 2014 PMID:25208284

  6. Alternation of regional homogeneity in trigeminal neuralgia after percutaneous radiofrequency thermocoagulation

    PubMed Central

    Dou, Zhi; Zhang, Xueyi; Yang, Liqiang; Wang, Wanqian; Li, Na; Liu, Zhicheng; Ni, Jiaxiang

    2016-01-01

    Abstract We used resting-state fMRI to investigate regional homogeneity (ReHo) changes in patients with TN before and after PRT procedure, and to speculate about its possible mechanisms. Thirty-one TN patients underwent the PRT procedure had MRI scans just before and 6 months after surgery. The anatomical and resting-state functional images were all acquired. Patients’ visual analog scales (VAS) scores, facial numbness, and disease duration were also recorded. Voxel-wise ReHo analysis was performed to detect the altered regional clusters after surgery. The correlations between the mean ReHo values of each significant cluster and clinical variables were examined. Compared with presurgical condition, patients after the PRT procedure showed a significant ReHo value increases in the right fusiform gyrus (FG) and bilateral anterior cingulate cortex (ACC), but decreases in the left inferior parietal lobule (IPL), right calcarine, right middle temporal gyrus (MTG), left postcentral gyrus (PoCG), and left insula. We demonstrated a positive correlation between ReHo in the left PoCG and VAS scores, a negative correlation between pre-surgical ReHo in the right MTG and VAS changes (ΔVAS). Alterations of ReHo post-surgical were found in several regions, which are related to sensory, affective, and emotional processes. The MTG may be a specific area that is associated with analgesic efficiency of PRT procedure. PMID:27759655

  7. Early and Late Complications After Radiofrequency Ablation of Malignant Liver Tumors in 608 Patients

    PubMed Central

    Curley, Steven A.; Marra, Paolo; Beaty, Karen; Ellis, Lee M.; Vauthey, J Nicolas; Abdalla, Eddie K.; Scaife, Courtney; Raut, Chan; Wolff, Robert; Choi, Haesun; Loyer, Evelyne; Vallone, Paolo; Fiore, Francesco; Scordino, Fabrizio; De Rosa, Vincenzo; Orlando, Raffaele; Pignata, Sandro; Daniele, Bruno; Izzo, Francesco

    2004-01-01

    Background: Radiofrequency ablation (RFA) has become a common treatment of patients with unresectable primary and secondary hepatic malignancies. We performed this prospective analysis to determine early (within 30 days) and late (more than 30 days after) complication rates associated with hepatic tumor RFA. Methods: All patients treated between January 1, 1996 and June 30, 2002 with RFA for hepatic malignancies were entered into a prospective database. Patients were evaluated during RFA treatment, throughout the immediate post RFA course, and then every 3 months after RFA to assess for the development of treatment-related complications. Results: A total of 608 patients, 345 men (56.7%) and 263 women (43.3%), with a median age of 58 years (range 18–85 years) underwent RFA of 1225 malignant liver tumors. Open intraoperative RFA was performed in 382 patients (62.8%), while percutaneous RFA was performed in 226 (37.2%). The treatment-related mortality rate was 0.5%. Early complications developed in 43 patients (7.1%). Early complications were more likely to occur in patients treated with open RFA (33 [8.6%] of 382 patients) compared with percutaneous RFA (10 [4.4%] 226 patients, P < 0.01), and in patients with cirrhosis (25 [12.9%] complications in 194 patients) compared with noncirrhotic patients (31 [7.5%] complications in 414 patients, P < 0.05). Late complications arose in 15 patients (2.4%) with no difference in incidence between open and percutaneous RFA treatment. The combined overall early and late complication rate was 9.5%. Conclusions: Hepatic tumor RFA can be performed with low mortality and morbidity rates. Though relatively rare, late complications can develop and physicians performing hepatic RFA must be cognizant of these delayed treatment-related problems. PMID:15024305

  8. Ultrasound-Guided Radiofrequency Thermal Ablation of Uterine Fibroids: Medium-Term Follow-Up

    SciTech Connect

    Carrafiello, Gianpaolo; Recaldini, Chiara Fontana, Federico; Ghezzi, Fabio; Cuffari, Salvatore; Lagana, Domenico; Fugazzola, Carlo

    2010-02-15

    Previous studies have shown that radiofrequency thermal ablation (RFA) of uterine fibroids through a percutaneous ultrasound (US)-guided procedure is an effective and safe minimally invasive treatment, with encouraging short-term results. The aim of this study was to assess the results in terms of volume reduction and clinical symptoms improvement in the midterm follow-up of fibroids with a diameter of up to 8 cm. Eleven premenopausal females affected by symptomatic fibroids underwent percutaneous US-guided RFA. Symptom severity and reduction in volume were evaluated at 1, 3, 6, 9, and 12 months. The mean symptom score (SSS) before the procedure was 50.30 (range 31.8-67.30), and the average quality of life (QOL) score value was 62 (range 37.20-86.00). The mean basal diameter was 5.5 cm (range 4.4-8) and the mean volume was 101.5 cm{sup 3} (range 44.58-278 cm{sup 3}). The mean follow-up was 9 months (range 3-12 months). The mean SSS value at the end of the follow-up was 13.38 (range 0-67.1) and the QOL 90.4 (range 43.8-100). At follow-up the mean diameter was 3.0 cm (range 1.20-4.5 cm), and the mean volume was 18 cm{sup 3} (range 0.90-47.6 cm{sup 3}). In 10 of 11 patients we obtained total or partial regression of symptoms. In one case the clinical manifestations persisted and it was thus considered unsuccessful. In conclusion, US-guided percutaneous RFA is a safe and effective treatment even for fibroids up to 8 cm.

  9. Radiofrequency radiation injures trees around mobile phone base stations.

    PubMed

    Waldmann-Selsam, Cornelia; Balmori-de la Puente, Alfonso; Breunig, Helmut; Balmori, Alfonso

    2016-12-01

    In the last two decades, the deployment of phone masts around the world has taken place and, for many years, there has been a discussion in the scientific community about the possible environmental impact from mobile phone base stations. Trees have several advantages over animals as experimental subjects and the aim of this study was to verify whether there is a connection between unusual (generally unilateral) tree damage and radiofrequency exposure. To achieve this, a detailed long-term (2006-2015) field monitoring study was performed in the cities of Bamberg and Hallstadt (Germany). During monitoring, observations and photographic recordings of unusual or unexplainable tree damage were taken, alongside the measurement of electromagnetic radiation. In 2015 measurements of RF-EMF (Radiofrequency Electromagnetic Fields) were carried out. A polygon spanning both cities was chosen as the study site, where 144 measurements of the radiofrequency of electromagnetic fields were taken at a height of 1.5m in streets and parks at different locations. By interpolation of the 144 measurement points, we were able to compile an electromagnetic map of the power flux density in Bamberg and Hallstadt. We selected 60 damaged trees, in addition to 30 randomly selected trees and 30 trees in low radiation areas (n=120) in this polygon. The measurements of all trees revealed significant differences between the damaged side facing a phone mast and the opposite side, as well as differences between the exposed side of damaged trees and all other groups of trees in both sides. Thus, we found that side differences in measured values of power flux density corresponded to side differences in damage. The 30 selected trees in low radiation areas (no visual contact to any phone mast and power flux density under 50μW/m(2)) showed no damage. Statistical analysis demonstrated that electromagnetic radiation from mobile phone masts is harmful for trees. These results are consistent with the fact

  10. Percutaneous Cementoplasty for Kienbock's Disease.

    PubMed

    Vallejo, Eduardo Crespo; Martinez-Galdámez, Mario; Martin, Ernesto Santos; de Gregorio, Arturo Perera; Gallego, Miriam Gamo; Escobar, Angeles Ramirez

    2017-03-08

    Kienböck disease typically presents with wrist pain, swelling, restricted range of motion, and difficulty in performing activities of daily living. Because the etiology and evolution of disease remain unclear, broad ranges of treatments have been designed. Percutaneous cementoplasty is expanding its role for managing painful bone metastases outside the spine. We can draw a parallel between lytic tumoral lesions and Kienbock's disease. Increasing the strength and rigidity of lunate with cementoplasty can prevent it from collapse, relieve the symptoms associated with the process of avascular necrosis, and increase the wrist range of motion. We report the case of 30-year-old man with a painful stage IIIA Kienböck disease who underwent percutaneous cementoplasty and experienced immediate effective pain relief and recovery of wrist mobility.

  11. Cangrelor in percutaneous coronary intervention.

    PubMed

    Oestreich, Julie H; Steinhubl, Steven R

    2009-03-01

    Cangrelor is a novel, intravenous P2Y12 receptor antagonist in development for use in percutaneous coronary intervention. Currently in Phase III testing, the reversible platelet inhibitor provides several inherent advantages over other P2Y12 receptor antagonists in this setting for the prevention of adverse cardiac events. Unlike the class of thienopyridines (ticlopidine, clopidogrel and potentially soon to be available, prasugrel), cangrelor has nearly immediate onset after a bolus dose and a short half-life, and achieves maximal inhibition of ADP-mediated platelet function. Cangrelor's distinct mechanism of action allows for intravenous administration and avoids both hepatic and renal metabolism. These unique characteristics make cangrelor a promising agent for use in cardiovascular patients undergoing percutaneous coronary intervention.

  12. Ocular effects of radiofrequency energy.

    PubMed

    Elder, J A

    2003-01-01

    Radiofrequency (RF) energy has been reported to cause a variety of ocular effects, primarily cataracts but also effects on the retina, cornea, and other ocular systems. Cataracts have been observed in experimental animals when one eye was exposed to a localized, very high RF field and the other eye was the unexposed control. The results show that 2450 MHz exposures for >or=30 min at power densities causing extremely high dose rates (>or=150 W/kg) and temperatures (>or=41 degrees C) in or near the lens caused cataracts in the rabbit eye. However, cataracts were not observed in the monkey eye exposed to similar exposure conditions, reflecting the different patterns of energy absorption (SAR, specific absorption rate) distribution, due to their different facial structure. Since the monkey head is similar in structure to the human head, the nonhuman primate study showed that the incident power density levels causing cataracts in rabbits and other laboratory animals cannot be directly extrapolated to primates, including human beings. It is reasonable to assume that an SAR that would induce temperatures >or=41 degrees C in or near the lens in the human eye would produce cataracts by the same mechanism (heating) that caused cataracts in the rabbit lens; however, such an exposure would greatly exceed the currently allowable limits for human exposure and would be expected to cause unacceptable effects in other parts of the eye and face. Other ocular effects including corneal lesions, retinal effects, and changes in vascular permeability, have been observed after localized exposure of the eye of laboratory animals to both continuous wave (CW) and pulsed wave (PW) exposures, but the inconsistencies in these results, the failure to independently confirm corneal lesions after CW exposure, the failure to independently confirm retinal effects after PW exposure, and the absence of functional changes in vision are reasons why these ocular effects are not useful in defining an

  13. Rationale and design of the randomized, double-blind trial testing INtraveNous and Oral administration of elinogrel, a selective and reversible P2Y(12)-receptor inhibitor, versus clopidogrel to eVAluate Tolerability and Efficacy in nonurgent Percutaneous Coronary Interventions patients (INNOVATE-PCI).

    PubMed

    Leonardi, Sergio; Rao, Sunil V; Harrington, Robert A; Bhatt, Deepak L; Gibson, C Michael; Roe, Matthew T; Kochman, Janusz; Huber, Kurt; Zeymer, Uwe; Madan, Mina; Gretler, Daniel D; McClure, Matthew W; Paynter, Gayle E; Thompson, Vivian; Welsh, Robert C

    2010-07-01

    Despite current dual-antiplatelet therapy with aspirin and clopidogrel, adverse clinical events continue to occur during and after percutaneous coronary intervention (PCI). The failure of clopidogrel to provide optimal protection may be related to delayed onset of action, interpatient variability in its effect, and an insufficient level of platelet inhibition. Furthermore, the irreversible binding of clopidogrel to the P2Y(12) receptor for the life span of the platelet is associated with increased bleeding risk especially during urgent or emergency surgery. Novel antiplatelet agents are required to improve management of patients undergoing PCI. Elinogrel is a potent, direct-acting (ie, non-prodrug), selective, competitive, and reversible P2Y(12) inhibitor available in both intravenous and oral formulations. The INNOVATE-PCI study is a phase 2 randomized, double-blind, clopidogrel-controlled trial to evaluate the safety, tolerability, and preliminary efficacy of this novel antiplatelet agent in patients undergoing nonurgent PCI.

  14. Percutaneous interstitial brachytherapy for adrenal metastasis: technical report

    PubMed Central

    Kishi, Kazushi; Tamura, Shinji; Mabuchi, Yasushi; Sonomura, Tetsuo; Noda, Yasutaka; Nakai, Motoki; Sato, Morio; Ino, Kazuhiko; Yamanaka, Noboru

    2012-01-01

    We developed and evaluated the feasibility of a brachytherapy technique as a safe and effective treatment for adrenal metastasis. Adapting a paravertebral insertion technique in radiofrequency ablation of adrenal tumors, we developed an interstitial brachytherapy for adrenal metastasis achievable on an outpatient basis. Under local anesthesia and under X-ray CT guidance, brachytherapy applicator needles were percutaneously inserted into the target. A treatment plan was created to eradicate the tumor while preserving normal organs including the spinal cord and kidney. We applied this interstitial brachytherapy technique to two patients: one who developed adrenal metastasis as the third recurrence of uterine cervical cancer after reirradiation, and one who developed metachronous multiple metastases from malignant melanoma. The whole procedure was completed in 2.5 hours. There were no procedure-related or radiation-related early/late complications. FDG PET-CT images at two and three months after treatment showed absence of FDG uptake, and no recurrence of the adrenal tumor was observed for over seven months until expiration, and for six months until the present, respectively. This interventional interstitial brachytherapy procedure may be useful as a safe and eradicative treatment for adrenal metastasis. PMID:22843376

  15. Percutaneous interstitial brachytherapy for adrenal metastasis: technical report.

    PubMed

    Kishi, Kazushi; Tamura, Shinji; Mabuchi, Yasushi; Sonomura, Tetsuo; Noda, Yasutaka; Nakai, Motoki; Sato, Morio; Ino, Kazuhiko; Yamanaka, Noboru

    2012-09-01

    We developed and evaluated the feasibility of a brachytherapy technique as a safe and effective treatment for adrenal metastasis. Adapting a paravertebral insertion technique in radiofrequency ablation of adrenal tumors, we developed an interstitial brachytherapy for adrenal metastasis achievable on an outpatient basis. Under local anesthesia and under X-ray CT guidance, brachytherapy applicator needles were percutaneously inserted into the target. A treatment plan was created to eradicate the tumor while preserving normal organs including the spinal cord and kidney. We applied this interstitial brachytherapy technique to two patients: one who developed adrenal metastasis as the third recurrence of uterine cervical cancer after reirradiation, and one who developed metachronous multiple metastases from malignant melanoma. The whole procedure was completed in 2.5 hours. There were no procedure-related or radiation-related early/late complications. FDG PET-CT images at two and three months after treatment showed absence of FDG uptake, and no recurrence of the adrenal tumor was observed for over seven months until expiration, and for six months until the present, respectively. This interventional interstitial brachytherapy procedure may be useful as a safe and eradicative treatment for adrenal metastasis.

  16. Modification of tubeless percutaneous nephrolithotomy with a ureteropelvic junction stent.

    PubMed

    Zhou, Tian C; Stern, Joshua M

    2017-10-01

    To introduce the ureteropelvic junction stent as a safe and effective modification to tubeless percutaneous nephrolithotomy for select patients to maintain antegrade access to the collecting system. From April 2014 to December 2015, 31 patients underwent modified tubeless percutaneous nephrolithotomy with ureteropelvic junction (UPJ) stent left in situ and an extraction string coming out the nephrostomy tract. Primary study endpoints included complications, emergency department visits, or re-admissions. Secondary endpoints were perioperative parameters including mean operative time, blood loss, length of stay, and time to stent removal. There were three Clavien grade III complications: one patient required exchange of her UPJ stent with a double-J stent due to distal ureteral obstruction and two patients required ureteroscopic retrieval of retained stents. Minor issues included one patient with stent discomfort and another who experienced a vasovagal response during stent removal. Patients stayed an average of 2.2 +/- 1.5 days, including six discharged same day. Of 31 patients, 30 were successfully drained by ureteropelvic junction stent. UPJ stent is a safe and effective modification to percutaneous nephrolithotomy to maintain antegrade access and minimize stent discomfort. Further studies should be performed to determine optimal candidate selection and quantify stent-related symptoms.

  17. Hemostatic Plug: Novel Technique for Closure of Percutaneous Nephrostomy Tract

    PubMed Central

    Cicic, Arman; Jump, Roger W.; Davalos, Julio G.

    2015-01-01

    Abstract Percutaneous nephrolithotomy (PCNL) is a standard treatment for patients with large or complex kidney stones. The procedure has traditionally included postoperative placement of a nephrostomy tube to allow for drainage and possible reentry. This practice was first implemented after complications incurred after tubeless PCNL in a small patient population. Recently, tubeless PCNL has reemerged as a viable option for selected patients, resulting in decreased pain and analgesic use, shorter hospitalization, quicker return to normal activity, and decreased urine extravasation. Gelatin matrix sealants are occasionally used in nephrostomy tract closure. Techniques for delivery of these agents have been ill described, and placement may be performed with varying results. We present a literature review comparing tubeless PCNL to its traditional variant with indications for use of each, as well as a comparison of agents used in closure. Finally, we outline a novel, reproducible technique for closure of the dilated percutaneous renal access tract. PMID:25157538

  18. Percutaneous catheter drainage of pancreatic pseudocysts.

    PubMed

    Adams, D B; Harvey, T S; Anderson, M C

    1991-01-01

    Pancreatic pseudocysts represent a complication of severe pancreatic inflammatory disease. Although operative drainage is the cornerstone of therapy for pseudocysts, we have undertaken percutaneous catheter drainage in a selected group of 28 patients over a six-year period (1982-88). This represents 42 per cent of pseudocyst patients managed by the senior author and 1.7 per cent of admissions for pancreatitis at the Medical University Hospitals during that period of time. There were 26 men and two women with an age range of 26-66 years (mean = 42.1). Twenty-six patients had alcohol abuse as the cause of pancreatitis; two were due to surgical trauma. Nondilated pancreatic ducts were demonstrated in 25 patients. Six had pancreatic ascites associated with pseudocysts. Four had previous operative drainage (2 internal and 2 external drainage procedures). Five patients received octreotide acetate, a synthetic peptide which mimics the action of somatostatin, in an attempt to aid closure of external fistulas. The mean length of catheter drainage was 48 days (range 7-210 days). Eight (29%) patients developed procedure-related complications (1 pneumothorax, 1 sheared guidewire, six drain tract infections). There was no mortality. Successful resolution of pseudocysts was achieved in 26 patients (93%). Two patients subsequently had elective caudal pancreaticojejunostomy (CPJ), and one lateral pancreaticojejunostomy (LPJ) to drain obstructed pancreatic ducts. One patient has required repeat external drainage. Percutaneous external drainage is successful in pseudocyst eradication. When underlying pancreatic pathology remains uncorrected, elective surgical decompression of obstructed, dilated ducts may be necessary.

  19. Radial scars without atypia in percutaneous biopsy specimens: can they obviate surgical biopsy?

    PubMed

    Mesa-Quesada, J; Romero-Martín, S; Cara-García, M; Martínez-López, A; Medina-Pérez, M; Raya-Povedano, J L

    2017-06-06

    To evaluate the need for surgical biopsy in patients diagnosed with radial scars without atypia by percutaneous biopsy. In this retrospective observational study, we selected patients with a histological diagnosis of radial scar in specimens obtained by percutaneous biopsy during an 8-year period. The statistical analysis was centered on patients with radial scar without atypia (we assessed the radiologic presentation, the results of the percutaneous biopsy, and their correlation with the results of surgical biopsy and follow-up) and we added the patients with atypia and cancer in the elaboration of the diagnostic indices. We identified 96 patients with radial scar on percutaneous biopsy; 54 had no atypia, 18 had atypia, and 24 had cancer. Among patients with radial scar without atypia, there were no statistically significant differences between patients who underwent imaging follow-up and those who underwent surgical biopsy (p>0.05). The rate of underdiagnosis for percutaneous biopsy in patients without atypia was 1.9%. The rates of diagnosis obtained with percutaneous biopsy in relation to follow-up and surgical biopsy in the 96 cases were sensitivity 92.3%, specificity 100%, positive predictive value 100%, negative predictive value 97.2%, and accuracy 97.9%. The area under the ROC curve was 0.96 (p<0.001), and the kappa concordance index was 0.95 (p<0.001) CONCLUSIONS: We consider that it is not necessary to perform surgical biopsies in patients with radial scars without atypia on percutaneous biopsies because the rate of underestimation is very low and the concordance between the diagnosis reached by percutaneous biopsy and the definitive diagnosis is very high. Copyright © 2017 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Efficacy of Percutaneous Adhesiolysis in the Treatment of Lumbar Post Surgery Syndrome

    PubMed Central

    Manchikanti, Laxmaiah; Manchikanti, Kavita N.; Gharibo, Christopher G.; Kaye, Alan D.

    2016-01-01

    Context Lumbar post-surgery syndrome is common and often results in chronic, persistent pain and disability, which can lead to multiple interventions. After failure of conservative treatment, either surgical treatment or a nonsurgical modality of treatment such as epidural injections, percutaneous adhesiolysis is often contemplated in managing lumbar post surgery syndrome. Recent guidelines and systematic reviews have reached different conclusions about the level of evidence for the efficacy of epidural injections and percutaneous adhesiolysis in managing lumbar post surgery syndrome. The objective of this systematic review was to determine the efficacy of all 3 percutaneous adhesiolysis anatomical approaches (caudal, interlaminar, and transforaminal) in treating lumbar post-surgery syndrome. Evidence Acquisition Data Sources: A literature search was performed from 1966 through October 2014 utilizing multiple databases. Study Selection: A systematic review of randomized trials published from 1966 through October 2014 of all types of epidural injections and percutaneous adhesiolysis in managing lumbar post-surgery syndrome was performed including methodological quality assessment utilizing Cochrane review criteria, Interventional Pain Management Techniques–Quality Appraisal of Reliability and Risk of Bias Assessment (IPM–QRB), and grading of evidence using 5 levels of evidence ranging from Level I to Level V. Data Extraction: The search strategy emphasized post-surgery syndrome and related pathologies treated with percutaneous adhesiolysis procedures. Results The search criteria yielded 16 manuscripts on percutaneous adhesiolysis assessing post-surgery syndrome. Of these, only 4 randomized trials met inclusion criteria for methodological quality assessment, 3 of them were of high quality; and the fourth manuscript was of low quality. Based on these 3 randomized controlled trials, 2 of them with one-day procedure and one with a 3-day procedure, the level of

  1. The optimal radiofrequency temperature in radiofrequency thermocoagulation for idiopathic trigeminal neuralgia: A cohort study.

    PubMed

    Tang, Yuan-Zhang; Yang, Li-Qiang; Yue, Jian-Ning; Wang, Xiao-Ping; He, Liang-Liang; Ni, Jia-Xiang

    2016-07-01

    Our previous study evaluated the effectiveness and safety of radiofrequency thermocoagulation (RFT) of trigeminal gasserian ganglion for idiopathic trigeminal neuralgia (ITN). The aim of this study was to evaluate the optimal radiofrequency temperature of computed tomography (CT)-guided RFT for treatment of ITN. A retrospective study of patients with ITN treated with a single CT-guided RFT procedure between January 2002 and December 2013. Patients were divided into ≤75 °C, 75 °C, and ≥80 °C groups according to the highest radiofrequency temperature used. Pain relief was graded from poor to excellent, and facial numbness/dysesthesia from I (absent) to IV (most severe). A total of 1161 RFT procedures were undertaken in the 1137 patients. The mean follow-up time was 46 ± 31 months. There were no significant differences in the rate of excellent pain relief according to the radiofrequency temperature used. However, more patients experienced with no facial numbness or facial numbness gradually resolved and those patients treated at 75 °C had a lower rate of grade IV facial numbness/dysesthesia than other groups. The optimal radiofrequency temperature to maximize pain relief and minimize facial numbness or dysesthesia may be 75 °C, but this requires confirmation.

  2. The optimal radiofrequency temperature in radiofrequency thermocoagulation for idiopathic trigeminal neuralgia

    PubMed Central

    Tang, Yuan-Zhang; Yang, Li-Qiang; Yue, Jian-Ning; Wang, Xiao-Ping; HE, Liang-Liang; NI, Jia-Xiang

    2016-01-01

    Abstract Objective: Our previous study evaluated the effectiveness and safety of radiofrequency thermocoagulation (RFT) of trigeminal gasserian ganglion for idiopathic trigeminal neuralgia (ITN). The aim of this study was to evaluate the optimal radiofrequency temperature of computed tomography (CT)-guided RFT for treatment of ITN. Methods: A retrospective study of patients with ITN treated with a single CT-guided RFT procedure between January 2002 and December 2013. Patients were divided into ≤75 °C, 75 °C, and ≥80 °C groups according to the highest radiofrequency temperature used. Pain relief was graded from poor to excellent, and facial numbness/dysesthesia from I (absent) to IV (most severe). Results: A total of 1161 RFT procedures were undertaken in the 1137 patients. The mean follow-up time was 46 ± 31 months. There were no significant differences in the rate of excellent pain relief according to the radiofrequency temperature used. However, more patients experienced with no facial numbness or facial numbness gradually resolved and those patients treated at 75 °C had a lower rate of grade IV facial numbness/dysesthesia than other groups. Conclusions: The optimal radiofrequency temperature to maximize pain relief and minimize facial numbness or dysesthesia may be 75 °C, but this requires confirmation. PMID:27428194

  3. [Radiofrequency ablation of a symptomatic benign thyroid nodule].

    PubMed

    van Ginhoven, T M; Massolt, E T; Bijdevaate, D C; Peeters, R P; Burgers, J W A; Moelker, A

    2016-01-01

    Radiofrequency ablation (RFA) enables the ablation of selected tissue by means of heat. For the first time in the Netherlands, RFA is being used to treat patients with benign thyroid nodules. RFA is able to reduce the volume of a nodule that may be causing cosmetic complaints or problems due to mass effect. This avoids the need for surgery or treatment with radioactive iodine in this benign condition. The average reduction in size is 80% in the first year, leading to a considerable decrease in both symptomatic and cosmetic complaints. At Erasmus Medical Centre, Rotterdam, the Netherlands, this technique has been introduced in accordance with current guidelines, and it is expected that other centres of excellence will follow in implementing it. It is important that the initial experiences with this technique in the Netherlands in terms of effectiveness, risks and patient satisfaction should be monitored before RFA becomes routine treatment.

  4. Cardiac Radiofrequency Ablation: A Clinical Update for Nurses.

    PubMed

    Shoulders, Bridget; Mauriello, Jillian; Shellman, Tamika; Follett, Corrinne

    2016-01-01

    The field of electrophysiology (EP) has rapidly evolved from a focus on diagnostic procedures to an emphasis on interventions. Many cardiac arrhythmias traditionally treated with antiarrhythmic agents, cardioversion, or cardiac surgery are now routinely cured with cardiac ablation. To optimally manage the care of cardiac ablation patients, it is essential that nurses have an understanding of the EP procedures and related nursing implications. There are extensive evidence-based resources available in the medical literature; however, there are limited publications geared toward nurses caring for cardiac ablation patients.This article provides an overview of EP diagnostic and cardiac radio-frequency ablation procedures for select atrial and ventricular tachyarrhythmias. Evidence-based nursing practices related to postprocedure care will be addressed. The objective of this article is to increase nurses' knowledge of common cardiac ablation procedures and the nursing management of the patient postprocedure.

  5. Laser and radiofrequency-induced hyperthermia treatment via gold-coated magnetic nanocomposites

    PubMed Central

    Elsherbini, Alsayed AM; Saber, Mahmoud; Aggag, Mohamed; El-Shahawy, Ahmed; Shokier, Hesham AA

    2011-01-01

    Introduction The current radiofrequency ablation technique requires invasive needle placement. On the other hand, most of the common photothermal therapeutic methods are limited by lack of accuracy of targeting. Gold and magnetic nanoparticles offer the potential to heat tumor tissue selectively at the cellular level by noninvasive interaction with laser and radiofrequency. Methods Gold nanospheres and gold-coated magnetic nanocomposites were used for inducing hyperthermia to treat subcutaneous Ehrlich carcinoma implanted in female mice. Results In mice treated with gold nanospheres, tumors continued to grow but at a slow rate. In contrast, more than 50% of the tumors treated with gold-coated magnetic nanocomposites completely disappeared. Conclusion This simple and noninvasive method shows great promise as a technique for selective magnetic photothermal treatment. PMID:22114479

  6. Skin tightening with fractional lasers, radiofrequency, Smartlipo.

    PubMed

    Collawn, Sherry S

    2010-05-01

    Skin tightening occurs with the use of fractional lasers, radiofrequency, and Smartlipo. The fractional lasers Fraxel (1550 nm; Solta Medical, Inc., Hayward, CA) and Affirm (1440 nm, 1320 nm) (Cynosure, Westford, MA) when used in combination tighten skin and lessen solar keratoses, and improve acne scars. With radiofrequency, further tightening occurs. Smartlipo (Cynosure, Westford, MA) (1064 nm or the newer MPX with combined 1064 nm and 1320 nm) results in skin tightening and has been very helpful in improving skin tightness and smoothness on the neck either singularly or in combination with the above procedures; and with the addition of the Affirm fractional CO2 laser (Cynosure, Westford, MA), further skin improvement and tightening occurs.

  7. Percutaneous transvenous mitral commissurotomy (PTMC) and percutaneous coronary intervention (PCI) successfully applied in one patient in same sitting.

    PubMed

    Sial, Jawaid Akbar; Farman, Muhammad Tariq; Saghir, Tahir; Zaman, Khan Shah

    2011-01-01

    Sixty years old male with severe rheumatic mitral stenosis (MS), presented with dyspnoea New York Heart Association (NHYA) class III to IV. Coronary angiogram revealed severe occlusive coronary artery disease in left anterior coronary artery (LAD). Percutaneous Transvenous Mitral Commissurotomy (PTMC) and Percutaneous Coronary Intervention (PCI) of Left Anterior Descurery (LAD) were done in same sitting. Both procedures were successful and ended without complication. After, half an hour while shifting to coronary care unit (CCU) patient developed cardiac tamponade, which was managed successfully. Patient was followed up for three month, he is doing well and recent echocardiogram showed mild mitral stenosis with normal left ventricular function. This case demonstrates the feasibility of the combined appliance on interventional techniques in selected patients as an alternative to cardiac surgery.

  8. Ophthalmic branch radiofrequency thermocoagulation for atypical trigeminal neuralgia:a case report.

    PubMed

    Du, Shibin; Ma, Xiaoliang; Li, Xiaoqin; Yuan, Hongjie

    2015-01-01

    Trigeminal neuralgia is an intense neuralgia involving facial areas supplied by trigeminal nerve. The pain is characterized by sudden onset, short persistence, sharp or lancinating. Trigeminal neuralgia commonly affects frontal areas, infraorbital or paranasal areas, mandibular areas and teeth. While Trigeminal neuralgia affecting merely the upper eyelid is rare. Here we report a case of atypical Trigeminal neuralgia confined to the upper eyelid. The patient was pain free during the follow-up period of 6 months after unusual ophthalmic branch radiofrequency thermocoagulation. A 55-year-old female patient was diagnosed as primary trigeminal neuralgia involving the right upper eyelid. As the pain could not be controlled by drug therapy, peripheral nerve branch radiofrequency thermocoagulation was recommended. A combination of infratrochlear, supratrochlear and lacrimal radiofrequency thermocoagulation was implemented in this case. The point where the bridge of the nose abuts the supraorbital ridge and the point slightly above the lateral canthus along outer border of the orbit were selected respectively as the puncture sites. After positive diagnostic test, radiofrequency thermocoagulation of the above-mentioned nerve branches was performed respectively. The patient was pain free immediately after the treatment and during the follow-up period of 6 months. Trigeminal neuralgia is a common severe and chronic facial neuralgia which requires accurate diagnosis and effective therapy. With typical clinical symptoms, normal neurological signs, normal CT and MRI findings, the patient was diagnosed as classic trigeminal neuralgia. As the patient was drug resistant, some invasive treatments were considered. Peripheral branch neurolysis was chosen for its minimal invasiveness, convenience, low risk and not affecting further invasive treatments. According to the anatomic data and the diagnostic test results, infratrochlear, supratrochlear and lacrimal nerve were responsible

  9. Radiofrequency and microwave radiation in the microelectronics industry.

    PubMed

    Cohen, R

    1986-01-01

    The microscopic precision required to produce minute integrated circuits is dependent on several processes utilizing radiofrequency and microwave radiation. This article provides a review of radiofrequency and microwave exposures in microelectronics and of the physical and biologic properties of these types of radiation; summarizes the existing, relevant medical literature; and provides the clinician with guidelines for diagnosis and treatment of excessive exposures to microwave and radiofrequency radiation.

  10. Superconducting surface impedance under radiofrequency field

    DOE PAGES

    Xiao, Binping P.; Reece, Charles E.; Kelley, Michael J.

    2013-04-26

    Based on BCS theory with moving Cooper pairs, the electron states distribution at 0K and the probability of electron occupation with finite temperature have been derived and applied to anomalous skin effect theory to obtain the surface impedance of a superconductor under radiofrequency (RF) field. We present the numerical results for Nb and compare these with representative RF field-dependent effective surface resistance measurements from a 1.5 GHz resonant structure.

  11. Superconducting surface impedance under radiofrequency field

    NASA Astrophysics Data System (ADS)

    Xiao, B. P.; Reece, C. E.; Kelley, M. J.

    2013-07-01

    Based on BCS theory with moving Cooper pairs, the electron states distribution at 0 K and the probability of electron occupation with finite temperature have been derived and applied to anomalous skin effect theory to obtain the surface impedance of a superconductor under radiofrequency (RF) field. We present the numerical results for Nb and compare these with representative RF field-dependent effective surface resistance measurements from a 1.5 GHz resonant structure.

  12. Radio-frequency association of Efimov trimers.

    PubMed

    Lompe, Thomas; Ottenstein, Timo B; Serwane, Friedhelm; Wenz, Andre N; Zürn, Gerhard; Jochim, Selim

    2010-11-12

    The quantum mechanical three-body problem is one of the fundamental challenges of few-body physics. When the two-body interactions become resonant, an infinite series of universal three-body bound states is predicted to occur, whose properties are determined by the strength of the two-body interactions. We used radio-frequency fields to associate Efimov trimers consisting of three distinguishable fermions. The measurements of their binding energy are consistent with theoretical predictions that include nonuniversal corrections.

  13. Bioeffects of Radiofrequency Radiation: A Review Pertinent to Air Force Operations.

    DTIC Science & Technology

    1983-03-01

    of research results and other pertinent information on the biological effects of radiofrequency radiation (RFR) to serve as a basis for determining...SECURITY CLASSIPFICATION OF THIS PAGE(tm Dat& Eed) 20. ABSTRACT (Contd) -ikely to be encountered in regions , around such systems, that are accessible...the biological effects of RFR was examined on a topic-by-topic basis . Representative articles were selected from the large body of scientific

  14. 21 CFR 870.1250 - Percutaneous catheter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Percutaneous catheter. 870.1250 Section 870.1250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1250 Percutaneous catheter...

  15. 21 CFR 870.1250 - Percutaneous catheter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Percutaneous catheter. 870.1250 Section 870.1250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1250 Percutaneous catheter...

  16. 21 CFR 870.1250 - Percutaneous catheter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Percutaneous catheter. 870.1250 Section 870.1250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1250 Percutaneous catheter...

  17. Short-echo-time magnetic resonance spectroscopy of single voxel with arbitrary shape in the living human brain using segmented two-dimensional selective radiofrequency excitations based on a blipped-planar trajectory.

    PubMed

    Weber-Fahr, Wolfgang; Busch, Martin G; Finsterbusch, Jürgen

    2009-06-01

    The target regions of single-voxel MR spectroscopy often deviate from the cuboidal volume acquired with localization methods based on cross-sectional RF excitations. To diminish partial volume effects spatially 2D-selective RF excitations (2DRF) have been used to excite anatomically defined regions of interest (ROIs). Thereby, segmentation of the 2DRF has been applied to avoid excessive pulse durations yielding "virtual" excitation profiles that are defined upon averaging multiple acquisitions obtained with the different segments. In this work, the feasibility of segmented 2DRF for single-voxel (1)H-MR spectroscopy of arbitrarily shaped voxel in the living human brain is demonstrated. The 2DRF segments were chosen to cover a single line of a blipped-planar trajectory in order to minimize chemical shift displacement artifacts and achieve standard echo times of 30 ms. To eliminate unwanted side excitations, a refocusing RF excitation in the blip direction was used. Phantom experiments demonstrate the high spatial selectivity achieved, i.e., the absence of significant signal contaminations from regions outside of the target volume. Although the signal obtained per volume is reduced compared to cross-sectional localization, the better volume coverage of anatomically defined ROIs can deliver an improved signal-to-noise ratio for irregularly shaped ROIs.

  18. Radiofrequency Microtenotomy for Elbow Epicondylitis: Midterm Results.

    PubMed

    Tasto, James P; Richmond, John M; Cummings, Jeffrey R; Hardesty, Renee; Amiel, David

    2016-01-01

    We conducted a prospective, nonrandomized, single-center clinical study to evaluate the safety and midterm effectiveness of microtenotomy using a radiofrequency probe to treat chronic tendinosis of the elbow. All patients had failed conservative treatment for 6 months. The radiofrequency-based microtenotomy was performed using the Topaz Microdebrider (ArthroCare). Patients were followed annually for up to 9 years postoperatively. Pain status was documented using a visual analog scale self-reported measure. Eighty consecutive patients with tendinosis of the elbow were enrolled; 69 patients were treated for lateral epicondylitis and 11 for medial epicondylitis. The duration of follow-up ranged from 6 months to 9 years (mean, 2.5 years). Ninety-one percent of the patients reported a successful outcome. Within the lateral epicondylitis group, the preoperative visual analog scale improved from 6.9 to 1.3 postoperatively and demonstrated an 81% improvement (P ≤ .01). For the medial epicondylitis patients, the preoperative visual analog scale improved from 6.1 to 1.3 after surgery, a 79% improvement (P ≤ .01). No complications were reported. Radiofrequency-based microtenotomy is a safe and effective procedure for elbow epicondylitis. The results are durable with successful outcomes observed at 9 years after surgery.

  19. [Immediate complications of feeding percutaneous gastrostomy: a 10-year experience].

    PubMed

    Chicharro, L; Puiggrós, C; Cots, I; Pérez-Portabella, C; Planas, M

    2009-01-01

    Percutaneous gastrostomy feeding tube (PG) may be beneficial in some patients, in others such as advanced dementia or rapidly progressive diseases its value is being questioned. Patient selection is important to identify those who will benefit from PG. This study aims to identify patients factors that may help in patient selection for PG. To analyse the characteristics of this patient's cohort and to describe the immediate complications of the procedure that we have defined as the ones happened in the first 30 days. To compare the two patient's group -with and without- immediate complications, non-parametric tests were used.

  20. [The percutaneous absorption of diclofenac].

    PubMed

    Riess, W; Schmid, K; Botta, L; Kobayashi, K; Moppert, J; Schneider, W; Sioufi, A; Strusberg, A; Tomasi, M

    1986-07-01

    The percutaneous absorption of diclofenac diethylammonium 1.16% (w/w) in a combination of emulsion cream and gel (Voltaren Emulgel) and of diclofenac sodium 1% (w/w) in a cream formulation (Voltaren cream) was investigated in guinea-pig, rabbit and man. The percutaneous absorption of diclofenac sodium in guinea-pig was 3 to 6% of the dose when the cream formulation in doses of 320, 100 or 40 mg was applied on 10 cm2 of occluded skin and left in place for 6 h. The transdermal delivery of 14C-labelled diclofenac yielded plateau plasma concentrations of radiotracer from 1.5 h after application until removal of the residual cream. Subsequently the steady state drug depots in the skin and muscle tissue were depleted promptly. During daily administration the steady state levels in the muscle tissue in proximity to the application site were about 3 times higher than in distant muscle tissue. By topical application on knee joints of rabbits diclofenac penetrated into the patellar ligament, the adipose corpus and the synovial fluid. In man the percutaneous absorption was 6% of the dose when the Emulgel formulation was spread by 5 mg/cm2 and left for 12 h on non-occluded skin. The pattern of metabolites of diclofenac in human urine was the same after topical and oral administration. In man, upon daily topical administration of 3 times 2.5 g cream formulation (10 mg/cm2) the diclofenac steady state plasma levels were 20 to 40 nmol/l.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Percutaneous diode laser disc nucleoplasty

    NASA Astrophysics Data System (ADS)

    Menchetti, P. P.; Longo, Leonardo

    2004-09-01

    The treatment of herniated disc disease (HNP) over the years involved different miniinvasive surgical options. The classical microsurgical approach has been substituted over the years both by endoscopic approach in which is possible to practice via endoscopy a laser thermo-discoplasty, both by percutaneous laser disc nucleoplasty. In the last ten years, the percutaneous laser disc nucleoplasty have been done worldwide in more than 40000 cases of HNP. Because water is the major component of the intervertebral disc, and in HNP pain is caused by the disc protrusion pressing against the nerve root, a 980 nm Diode laser introduced via a 22G needle under X-ray guidance and local anesthesia, vaporizes a small amount of nucleous polposus with a disc shrinkage and a relief of pressure on nerve root. Most patients get off the table pain free and are back to work in 5 to 7 days. Material and method: to date, 130 patients (155 cases) suffering for relevant symptoms therapy-resistant 6 months on average before consulting our department, have been treated. Eightyfour (72%) males and 46 (28%) females had a percutaneous laser disc nucleoplasty. The average age of patients operated was 48 years (22 - 69). The level of disc removal was L3/L4 in 12 cases, L4/L5 in 87 cases and L5/S1 in 56 cases. Two different levels were treated at the same time in 25 patients. Results: the success rate at a minimum follow-up of 6 months was 88% with a complication rate of 0.5%.

  2. Percutaneous epicardial ablation of incessant atrial tachycardia originating from the left atrial appendage

    PubMed Central

    Ban, Ji-Eun; Park, Tae Young

    2016-01-01

    A 38-year-old woman presented with antiarrhythmic drug-refractory atrial tachycardia (AT). Holter recording demonstrated incessant episodes of AT followed by a long sinus pause. Electrophysiologic study revealed that the earliest endocardial activation was observed at the neck of the left atrial appendage (LAA). After unsuccessful endocardial ablation, epicardial access via a percutaneous subxiphoid approach demonstrated that the earliest epicardial atrial activation was observed on the opposite site to the endocardial LAA neck suggestive of ligament of Marshall (LOM) muscle sleeve as regarding the epicardial sharp potentials under guidance of a circular mapping catheter. Application of radiofrequency (RF) energy at this site terminated the tachycardia. After tachycardia ablation, the sinus pause also resolved. PMID:28066659

  3. Comparison of Percutaneous Ablation Technologies in the Treatment of Malignant Liver Tumors

    PubMed Central

    Yu, Hyeon; Burke, Charles T.

    2014-01-01

    Tumor ablation is a minimally invasive technique used to deliver chemical, thermal, electrical, or ultrasonic damage to a specific focal tumor in an attempt to achieve substantial tumor destruction or complete eradication. As the technology continues to advance, several image-guided tumor ablations have emerged to effectively manage primary and secondary malignancies in the liver. Percutaneous chemical ablation is one of the oldest and most established techniques for treating small hepatocellular carcinomas. However, this technique has been largely replaced by newer modalities including radiofrequency ablation, microwave ablation, laser-induced interstitial thermotherapy, cryoablation, high-intensity–focused ultrasound ablation, and irreversible electroporation. Because there exist significant differences in underlying technological bases, understanding each mechanism of action is essential for achieving desirable outcomes. In this article, the authors review the current state of each ablation method including technological and clinical considerations. PMID:25071303

  4. Percutaneous Surgery of the Forefoot.

    PubMed

    Redfern, David; Vernois, Joel; Legré, Barbara Piclet

    2015-07-01

    This article describes some of the common techniques used in percutaneous surgery of the forefoot. Techniques such as minimally invasive chevron Akin osteotomy for correction of hallux valgus, first metatarsophalangeal joint cheilectomy, distal minimally invasive metatarsal osteotomies, bunionette correction, and hammertoe correction are described. This article is an introduction to this rapidly developing area of foot and ankle surgery. Less invasive techniques are continually being developed across the whole spectrum of surgical specialties. The surgical ethos of minimizing soft-tissue disruption in the process of achieving surgical objectives remains at the center of this evolution.

  5. Percutaneous transluminal angioplasty: newer applications.

    PubMed

    Novelline, R A

    1980-11-01

    Recent experience suggests that there is a wider spectrum of applications for percutaneous transluminal angioplasty than just dilating lesions of the ileofemoral, popliteal, renal and coronary arteries. Atherosclerotic and nonatherosclerotic lesions of other blood vessels as well as postoperative stenoses may be treated. Five patients from Massachusetts General Hospital are described in whom transluminal angioplasty was successful in relieving atherosclerotic stenoses of the axillary, subclavian, and superior mesenteric arteries; a stenotic, splenorenal shunt anastomosis; and an anastomotic stenosis in a renal dialysis angioaccess shunt. The experience of other investigators in dealing with these less common applications of transluminal angioplasty is summarized.

  6. Transurethral radiofrequency collagen denaturation for the treatment of women with urinary incontinence.

    PubMed

    Kang, Diana; Han, Julia; Neuberger, Molly M; Moy, M Louis; Wallace, Sheila A; Alonso-Coello, Pablo; Dahm, Philipp

    2015-03-18

    Transurethral radiofrequency collagen denaturation is a relatively novel, minimally invasive device-based intervention used to treat individuals with urinary incontinence (UI). No systematic review of the evidence supporting its use has been published to date. To evaluate the efficacy of transurethral radiofrequency collagen denaturation, compared with other interventions, in the treatment of women with UI.Review authors sought to compare the following.• Transurethral radiofrequency collagen denaturation versus no treatment/sham treatment.• Transurethral radiofrequency collagen denaturation versus conservative physical treatment.• Transurethral radiofrequency collagen denaturation versus mechanical devices (pessaries for UI).• Transurethral radiofrequency collagen denaturation versus drug treatment.• Transurethral radiofrequency collagen denaturation versus injectable treatment for UI.• Transurethral radiofrequency collagen denaturation versus other surgery for UI. We conducted a systematic search of the Cochrane Incontinence Group Specialised Register (searched 19 December 2014), EMBASE and EMBASE Classic (January 1947 to 2014 Week 50), Google Scholar and three trials registries in December 2014, along with reference checking. We sought to identify unpublished studies by handsearching abstracts of major gynaecology and urology meetings, and by contacting experts in the field and the device manufacturer. Randomised and quasi-randomised trials of transurethral radiofrequency collagen denaturation versus no treatment/sham treatment, conservative physical treatment, mechanical devices, drug treatment, injectable treatment for UI or other surgery for UI in women were eligible. We screened search results and selected eligible studies for inclusion. We assessed risk of bias and analysed dichotomous variables as risk ratios (RRs) with 95% confidence intervals (CIs) and continuous variables as mean differences (MDs) with 95% CIs. We rated the quality of

  7. Percutaneous angioplasty of a chronic total occlusion of the intracranial internal carotid artery. Case report.

    PubMed

    Komiyama, Masaki; Yoshimura, Masaki; Honnda, Yuji; Matsusaka, Yasuhiro; Yasui, Toshihiro

    2006-11-01

    A CTO of the intracranial ICA is usually managed medically and rarely by EC-IC bypass in selected patients. Percutaneous transluminal angioplasty has not been used. A 73-year-old man presented with frequent temporary blindness of the left eye and dizziness due to thrombotic occlusion of the left intracranial ICA, causing hemodynamic compromise. This patient was successfully treated by percutaneous angioplasty (balloon angioplasty and stent placement) under proximal balloon protection at 7 weeks from the ictus. Ischemic symptoms had not recurred during the 6-month follow-up period. Percutaneous angioplasty for a CTO of the intracranial ICA is technically feasible and can be an alternative to EC-IC bypass in a selected group of patients with symptomatic hemodynamic compromise, which is refractory to the best medical treatment.

  8. Epicardial Atrial Ablation Using a Novel Articulated Robotic Medical Probe Via a Percutaneous Subxiphoid Approach.

    PubMed

    Ota, Takeyoshi; Degani, Amir; Zubiate, Brett; Wolf, Alon; Choset, Howie; Schwartzman, David; Zenati, Marco A

    2006-01-01

    OBJECTIVE: Minimally invasive epicardial atrial ablation to cure atrial fibrillation through the use of a percutaneous subxiphoid approach currently has a lack of dedicated technology for intrapericardial navigation around the beating heart. We have developed a novel articulated robotic medical probe and performed preliminary experiments in a porcine preparation. METHODS: In five large, healthy pigs, the teleoperated robotic system was introduced inside the pericardial space through a percutaneous subxiphoid approach. Secondary visualization of the left atrium and left atrial appendage was achieved with the use of a 5-mm scope inserted through a left thoracic port. The operator actively controlled the path of the robot by using a master manipulator. The catheter, with an irrigated radiofrequency tip, was guided through the working port of the robot to achieve epicardial ablation of the left atrium. RESULTS: Access to the pericardial space and progression around the left atrium was successful in all cases, with no interference with the beating heart such as a fatal arrhythmia, unexpected bleeding, and hypotension. Epicardial ablation was successfully performed in all five cases. No adverse hemodynamic or electrophysiological events were noted during the trials. When the animals were killed, there was no visually detected injury on the surrounding mediastinal structures caused by ablation. Transmural ablation was confirmed by histopathology of the left atrium. CONCLUSIONS: We have developed a dedicated articulated robotic medical probe and successfully performed epicardial left atrial radiofrequency ablation. Based on the feedback from these preliminary experiments, the radius of curvature and proper visualization of the device are being improved in the next generation prototype.

  9. Radiofrequency trigeminal rhizolysis for the treatment of trigeminal neuralgia secondary to brainstem infarction. Report of two cases.

    PubMed

    Foroohar, M; Herman, M; Heller, S; Levy, R M

    1997-01-15

    Although percutaneous radiofrequency trigeminal rhizolysis (RFL) has been used to treat idiopathic trigeminal neuralgia thought secondary to multiple sclerosis, the use of RFL for trigeminal neuralgia caused by brainstem infarction has not been advocated. The authors report two patients with trigeminal neuralgia following pontine infarction in whom aggressive medical management failed, but who were successfully treated with RFL. Pain relief has persisted for the 3- and 6-year duration of follow-up examinations. Descending trigeminal reticular fibers may be affected by brainstem infarction and result in trigeminal neuralgia; thus, treatment by rhizotomy may be effective in decreasing the peripheral afferent input into the spinal trigeminal nucleus thus decreasing the pain. These two cases demonstrate the utility of RFL in the relief of ischemia-induced trigeminal neuralgia and lead the authors to suggest that its use be broadened to include this indication.

  10. Radiofrequency stimulation of intervertebral discs.

    PubMed

    Rosen, Steven; Falco, Frank

    2003-10-01

    The etiology of discogenic pain is poorly understood. The most accepted theory has been that nociceptors in the outer one-third of the annulus fibrosis are responsible for transmitting pain secondary to internal disc disruptions. The concept of "neoneuralization" after disc injury has been disseminated. It has been noted that disc degeneration and injury are associated with ingrowth of neural fibers into the disc annulus. One mechanism of Intradiscal Electrodothermal Therapy (IDET) has been thought to be lesioning of these nociceptors. Five consecutive patients were studied using an intraannular electrode. The Radionics discTRODE was used. It was found impossible to selectively stimulate axial pain fibers using this system. Radicular stimulation was noted in all patients at all levels studied. The implication of these findings concerning the concept of neoneuralization, mechanism of IDET, and possible strategies to decrease discogenic pain are discussed.

  11. 21 CFR 886.4100 - Radiofrequency electrosurgical cautery apparatus.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiofrequency electrosurgical cautery apparatus. 886.4100 Section 886.4100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... electrosurgical cautery apparatus. (a) Identification. A radiofrequency electrosurgical cautery apparatus is an AC...

  12. 21 CFR 886.4100 - Radiofrequency electrosurgical cautery apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency electrosurgical cautery apparatus. 886.4100 Section 886.4100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... electrosurgical cautery apparatus. (a) Identification. A radiofrequency electrosurgical cautery apparatus is an AC...

  13. 21 CFR 882.4400 - Radiofrequency lesion generator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radiofrequency lesion generator. 882.4400 Section 882.4400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... lesion generator. (a) Identification. A radiofrequency lesion generator is a device used to produce...

  14. 21 CFR 882.4400 - Radiofrequency lesion generator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radiofrequency lesion generator. 882.4400 Section 882.4400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... lesion generator. (a) Identification. A radiofrequency lesion generator is a device used to produce...

  15. 21 CFR 882.4400 - Radiofrequency lesion generator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radiofrequency lesion generator. 882.4400 Section 882.4400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... lesion generator. (a) Identification. A radiofrequency lesion generator is a device used to produce...

  16. 21 CFR 882.4400 - Radiofrequency lesion generator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiofrequency lesion generator. 882.4400 Section 882.4400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... lesion generator. (a) Identification. A radiofrequency lesion generator is a device used to produce...

  17. 21 CFR 882.4400 - Radiofrequency lesion generator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency lesion generator. 882.4400 Section 882.4400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... lesion generator. (a) Identification. A radiofrequency lesion generator is a device used to produce...

  18. CT-guided radiofrequency tumor ablation in children.

    PubMed

    Botsa, Evanthia; Poulou, Loukia S; Koutsogiannis, Ioannis; Ziakas, Panayiotis D; Koundouraki, Antonia; Alexopoulou, Efthimia; Thanos, Loukas

    2014-11-01

    Image-guided radiofrequency ablation is a well-accepted technique of interventional oncology in adults. To evaluate the efficacy and safety of CT-guided radiofrequency ablation as a minimally invasive treatment for metastatic neoplasms in children. 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. 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. CT-guided radiofrequency tumor ablation was safe and efficient for palliative treatment in our cohort of patients.

  19. Percutaneous ablation for atrial fibrillation: the role of cross-sectional imaging.

    PubMed

    Ghaye, Benoit; Szapiro, David; Dacher, Jean-Nicolas; Rodriguez, Luz-Maria; Timmermans, Carl; Devillers, David; Dondelinger, Robert F

    2003-10-01

    Percutaneous ablation is a well-established technique for treating cardiac arrhythmia by removing or isolating tissue at the site of the abnormal impulse formation. Various forms of energy for ablation procedures may be delivered via a catheter with fluoroscopic guidance. The procedures most commonly performed are radiofrequency ablation and cryotherapy. Atrial fibrillation, the most frequently occurring supraventricular tachyarrhythmia, may be initiated by ectopic beats that originate in the ostia of the pulmonary veins. The clinical efficacy of isolation (or focal ablation) of the pulmonary veins for treatment of atrial fibrillation has been well demonstrated. Pre- and postprocedural examinations with computed tomography (CT) or magnetic resonance (MR) imaging are frequently performed to depict the anatomy and to obtain baseline measurements of the pulmonary veins to enable early detection of complications from ablation. Venous stenosis or thrombosis and pulmonary hypertension may occur after radio-frequency ablation. Familiarity with the appearance of normal anatomic variants at CT and MR imaging and with the normal range of pulmonary vein diameters is essential for preoperative management and early detection of procedure-related complications. Copyright RSNA, 2003

  20. A randomized controlled trial of radiofrequency denervation of the ramus communicans nerve for chronic discogenic low back pain.

    PubMed

    Oh, Wan Soo; Shim, Jae Chol

    2004-01-01

    The objective of this study was to determine the efficacy of percutaneous radiofrequency (RF) thermocoagulation of the ramus communicans nerve in patients suffering from chronic discogenic low back pain. Forty-nine patients who suffered chronic discogenic low back pain at only 1 painful vertebral level, and whose pain continued after undergoing intradiscal electrothermal annuloplasty (IDET), were randomly assigned to 1 of 2 treatment groups. The lesion group (n = 26) received RF thermocoagulation of the ramus communicans nerve. Patients in the control group (n = 23) received an injection of lidocaine without radiofrequency. Visual analog scale (VAS) pain scores, analgesic requirements, SF-36 subscales, and the overall patient satisfaction with the procedure were tabulated. The average follow-up period was 4 months. The patient-reported VAS pain scores were significantly lower (P < 0.05) in the lesion group. The scores of the RF lesion group improved by a mean increase of 11.3 points (P < 0.05) on the SF-36 bodily pain subscale, and by a mean increase of 12.4 points on the physical function subscale (P < 0.05). In a follow-up analysis within the RF lesion group, VAS pain scores improved by a mean reduction of 3.32 (P = 0.001). The scores improved by a mean increase of 14.5 points (P = 0.005) on the SF-36 bodily pain subscale and 15.2 points(P = 0.002) on the physical function subscale within the RF lesion group. One patient in the lesion group complained of mild lower limb weakness, but he completely recovered at postoperative 15 days without any serious problems. In patients with chronic discogenic low back pain, percutaneous RF denervation of the ramus communicans nerve should be considered as a treatment option.

  1. Development of a novel loosely wound helical coil for interstitial radiofrequency thermal therapy.

    PubMed

    McCann, Claire; Sherar, Michael D

    2006-08-07

    We have developed a novel, radiofrequency thermal therapy device designed to improve local control of large solid tumours using heat in the range 55-90 degrees C. The device is a solenoid or helical coil designed to be loosely wound inside a tumour and excited with radiofrequency energy. Typically, we associate a uniform axially directed magnetic field with a solenoid coil, which when time varying, results in an electric field inside the coil, which lies mainly in the circumferential direction. In addition to this magnetically induced electric field, there exists a less familiar axially directed electric field inside the coil. Previous investigators have demonstrated the presence of this secondary axial electric field both experimentally and theoretically. Our design exploits the size and uniformity of these electric fields, for heating and coagulating a large tissue volume with a single applicator. The loosely wound solenoid is constructed from Nitinol, an electrically conductive shape memory alloy that permits the minimally invasive percutaneous insertion of the coil through a single cannulating delivery needle. To demonstrate the potential of this device and to determine the optimal frequency of operation, phantom tissue models and finite-element calculation models using COMSOL 3.2 were used to characterize frequency- and geometry-dependent trends in absorption rate density (ARD), which is proportional to electric field intensity. Radial and axial ARD profiles were measured, calculated and evaluated to determine the frequency and geometry best suited for producing large, homogenous coagulation volumes. Based on the trade-off between radial and axial uniformities of the ARD profiles, a 2 cm diameter coil with a 4 cm length and 1 cm pitch, operated at 27.12 MHz, produced the optimal heating pattern, as determined using tissue-mimicking phantom models.

  2. Radio-frequency measurement in semiconductor quantum computation

    NASA Astrophysics Data System (ADS)

    Han, TianYi; Chen, MingBo; Cao, Gang; Li, HaiOu; Xiao, Ming; Guo, GuoPing

    2017-05-01

    Semiconductor quantum dots have attracted wide interest for the potential realization of quantum computation. To realize efficient quantum computation, fast manipulation and the corresponding readout are necessary. In the past few decades, considerable progress of quantum manipulation has been achieved experimentally. To meet the requirements of high-speed readout, radio-frequency (RF) measurement has been developed in recent years, such as RF-QPC (radio-frequency quantum point contact) and RF-DGS (radio-frequency dispersive gate sensor). Here we specifically demonstrate the principle of the radio-frequency reflectometry, then review the development and applications of RF measurement, which provides a feasible way to achieve high-bandwidth readout in quantum coherent control and also enriches the methods to study these artificial mesoscopic quantum systems. Finally, we prospect the future usage of radio-frequency reflectometry in scaling-up of the quantum computing models.

  3. Radiofrequency energy in surgery: state of the art.

    PubMed

    Ihnát, Peter; Ihnát Rudinská, Lucia; Zonča, Pavel

    2014-06-01

    Over a period of more than 100 years, radiofrequency energy has been introduced in many fields and applications in medicine. At present, radiofrequency constitutes the basis of numerous medical devices employed in almost all medical specialties. It is particularly applicable and valuable in various minimally invasive procedures for its locally focused effects. Radiofrequency energy is a technical term established to describe high-frequency alternating electrical currents (with a frequency ranging from 300 kHz to 3 MHz) and their impact on biological tissue. The application of RF energy causes controlled tissue heating with consequent cell protein denaturation and desiccation, which leads to cell death and tissue destruction. The primary principle of radiofrequency is that the generated heat can be used to cut, coagulate or induce metabolic processes in the target tissue. The authors of this paper offer a comprehensive and compact review of the definition, history, physics, biological principles and applications of radiofrequency energy in current surgery.

  4. The Role of Percutaneous Image-Guided Thermal Ablation for the Treatment of Pulmonary Malignancies.

    PubMed

    Mouli, Samdeep K; Kurilova, Ieva; Sofocleous, Constantinos T; Lewandowski, Robert J

    2017-10-01

    Image-guided thermal ablation is a minimally invasive treatment option for patients with primary and secondary pulmonary malignancies. Modalities include radiofrequency ablation, microwave ablation, and cryoablation. Although no large randomized studies exist comparing ablation to surgery or radiotherapy, numerous studies have reported safety and efficacy for the treatment of both primary and metastatic disease in select patients. Future studies will refine patient selection, procedural technique, and assessment for local recurrence and will evaluate long-term survival.

  5. Dynamic Article: Percutaneous Nerve Evaluation Versus Staged Sacral Nerve Stimulation for Fecal Incontinence.

    PubMed

    Rice, Teresa C; Quezada, Yarini; Rafferty, Janice F; Paquette, Ian M

    2016-10-01

    Sacral neuromodulation using a 2-staged approach is an established therapy for fecal incontinence. Office-based percutaneous nerve evaluation is a less-invasive alternative to the stage 1 procedure but is seldom used in the evaluation of patients with fecal incontinence. The aim of this study was to determine the clinical success of percutaneous nerve evaluation versus a staged approach. This was a retrospective review of a prospectively maintained, single-institution database of patients treated with sacral neuromodulation for fecal incontinence. This study was conducted at a single academic medical center. Eighty-six consecutive patients were treated with sacral neuromodulation for fecal incontinence. Percutaneous nerve evaluation was compared with a staged approach. The primary outcome measured was the proportion of patients progressing to complete implantation based on >50% improvement in Wexner score during the testing phase. Percutaneous nerve evaluation was performed in 45 patients, whereas 41 underwent a staged approach. The mean baseline Wexner score did not differ between testing groups. Success was similar between the staged approach and percutaneous nerve evaluation (90.2% versus 82.2%; p = 0.36). The mean 3-month Wexner score was not significantly different between testing methods (4.4 versus 4.1; p = 0.74). However, infection was more likely to occur after the staged approach (10.5% versus 0.0%; p < 0.05). This study was limited by its retrospective nature and potential for selection bias. Percutaneous nerve evaluation offers a viable alternative to a staged approach in the evaluation of patients for sacral neuromodulation in the setting of fecal incontinence. Not only are success rates similar, but percutaneous nerve evaluation also has the benefit of limiting patients to 1 operating room visit and has lower rates of infection as compared with the traditional staged approach for sacral neuromodulation.

  6. [In vitro study of radiofrequency thermal angioplasty].

    PubMed

    Koyama, T; Sawada, S; Tanigawa, N; Tsutsumi, S; Fujihara, Y; Saito, S; Katsube, Y; Morioka, N

    1990-08-25

    We performed some in vitro experiments using a radiofrequency thermal angioplasty instrument. The distribution of heat emitted from the hot tip of the device was evaluated in an agar phantom by thermography and it produced a concentric circular pattern. The temperature of the hot tip was about 290 degrees C when measured by thermocouples in the air. When the RF probe approached perpendicularly to the cadaver arterial wall, a crater with charring and coagulating necrosis was formed. However, when the RF probe traveled parallel to the arterial wall, as in normal practice, it did not seem to perforate the artery. The device could ablate non-calcified atheromatous plaque.

  7. Active stabilization of ion trap radiofrequency potentials

    SciTech Connect

    Johnson, K. G.; Wong-Campos, J. D.; Restelli, A.; Landsman, K. A.; Neyenhuis, B.; Mizrahi, J.; Monroe, C.

    2016-05-15

    We actively stabilize the harmonic oscillation frequency of a laser-cooled atomic ion confined in a radiofrequency (rf) Paul trap by sampling and rectifying the high voltage rf applied to the trap electrodes. We are able to stabilize the 1 MHz atomic oscillation frequency to be better than 10 Hz or 10 ppm. This represents a suppression of ambient noise on the rf circuit by 34 dB. This technique could impact the sensitivity of ion trap mass spectrometry and the fidelity of quantum operations in ion trap quantum information applications.

  8. Radiofrequency ablation for benign thyroid nodules.

    PubMed

    Bernardi, S; Stacul, F; Zecchin, M; Dobrinja, C; Zanconati, F; Fabris, B

    2016-09-01

    Benign thyroid nodules are an extremely common occurrence. Radiofrequency ablation (RFA) is gaining ground as an effective technique for their treatment, in case they become symptomatic. Here we review what are the current indications to RFA, its outcomes in terms of efficacy, tolerability, and cost, and also how it compares to the other conventional and experimental treatment modalities for benign thyroid nodules. Moreover, we will also address the issue of treating with this technique patients with cardiac pacemakers (PM) or implantable cardioverter-defibrillators (ICD), as it is a rather frequent occurrence that has never been addressed in detail in the literature.

  9. Survival outcome of salvage hepatectomy in patients with local, recurrent hepatocellular carcinoma who underwent radiofrequency ablation as their first treatment.

    PubMed

    Ueno, Masaki; Nakai, Takuya; Hayashi, Michihiro; Hirokawa, Fumitoshi; Nagano, Hiroaki; Wada, Hiroshi; Kaibori, Masaki; Matsui, Kosuke; Tanaka, Shogo; Yamaue, Hiroki; Kubo, Shoji

    2016-09-01

    Local recurrence is a specific problem after radiofrequency ablation of small hepatocellular carcinoma, and additional treatment is an important issue. We aimed to investigate the outcome of salvage hepatectomy in patients who develop local, recurrent hepatocellular carcinoma after treatment with radiofrequency ablation. From 2001-2013, we reviewed 58 patients from 6 university hospitals with local, recurrent hepatocellular carcinoma who underwent salvage hepatectomy after their initial radiofrequency ablation treatment. Pathologic characteristics and prognostic factors influencing overall survival were analyzed. Noncurative resection, des-gamma carboxy prothrombin levels >40 mAU/mL, and multiple preceding treatments before salvage hepatectomy were negative prognostic factors for overall survival. The 5-year survivals for the prognostic factors were 0%, 24%, and 30%, respectively, after salvage hepatectomy, and 0%, 54%, and 54% after initial radiofrequency ablation treatment, respectively. As for the pathologic finding of local, recurrent hepatocellular carcinoma after radiofrequency ablation, vascular invasion was observed frequently in patients with increases in des-gamma carboxy prothrombin levels and with multiple preceding treatments before salvage hepatectomy with a frequency of 59% and 53%, respectively (P < .01 and .05). Noncurative resection, increases in serum des-gamma carboxy prothrombin, and multiple preceding treatments were prognostic factors for subsequent salvage hepatectomy; nevertheless, survival outcomes were still acceptable when a curative salvage hepatectomy was performed. Increases in serum des-gamma carboxy prothrombin and multiple preceding treatments were positive predictors for pathologic vascular invasion. These factors should be taken into consideration when selecting treatment modalities for locally recurrent hepatocellular carcinoma following radiofrequency ablation. Repetition of unsuccessful, loco-regional treatment would appear

  10. Radiofrequency ablation of hepatocellular carcinoma: Mono or multipolar?

    PubMed

    Cartier, Victoire; Boursier, Jérôme; Lebigot, Jérôme; Oberti, Frédéric; Fouchard-Hubert, Isabelle; Aubé, Christophe

    2016-03-01

    Thermo-ablation by radiofrequency is recognized as a curative treatment for early-stage hepatocellular carcinoma. However, local recurrence may occur because of incomplete peripheral tumor destruction. Multipolar radiofrequency has been developed to increase the size of the maximal ablation zone. We aimed to compare the efficacy of monopolar and multipolar radiofrequency for the treatment of hepatocellular carcinoma and determine factors predicting failure. A total of 171 consecutive patients with 214 hepatocellular carcinomas were retrospectively included. One hundred fifty-eight tumors were treated with an expandable monopolar electrode and 56 with a multipolar technique using several linear bipolar electrodes. Imaging studies at 6 weeks after treatment, then every 3 months, assessed local effectiveness. Radiofrequency failure was defined as persistent residual tumor after two sessions (primary radiofrequency failure) or local tumor recurrence during follow-up. This study received institutional review board approval (number 2014/77). Imaging showed complete tumor ablation in 207 of 214 lesions after the first session of radiofrequency. After a second session, only two cases of residual viable tumor were observed. During follow-up, there were 46 local tumor recurrences. Thus, radiofrequency failure occurred in 48/214 (22.4%) cases. By multivariate analysis, technique (P < 0.001) and tumor size (P = 0.023) were independent predictors of radiofrequency failure. Failure rate was lower with the multipolar technique for tumors < 25 mm (P = 0.023) and for tumors between 25 and 45 mm (P = 0.082). There was no difference for tumors ≥ 45 mm (P = 0.552). Compared to monopolar radiofrequency, multipolar radiofrequency improves tumor ablation with a subsequent lower rate of local tumor recurrence. © 2015 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  11. Percutaneous CT and Fluoroscopy-Guided Screw Fixation of Pathological Fractures in the Shoulder Girdle: Technical Report of 3 Cases.

    PubMed

    Garnon, Julien; Koch, Guillaume; Ramamurthy, Nitin; Caudrelier, Jean; Rao, Pramod; Tsoumakidou, Georgia; Cazzato, Roberto Luigi; Gangi, Afshin

    2016-09-01

    To review our initial experience with percutaneous CT and fluoroscopy-guided screw fixation of pathological shoulder-girdle fractures. Between May 2014 and June 2015, three consecutive oncologic patients (mean age 65 years; range 57-75 years) with symptomatic pathological shoulder-girdle fractures unsuitable for surgery and radiotherapy underwent percutaneous image-guided screw fixation. Fractures occurred through metastases (n = 2) or a post-ablation cavity (n = 1). Mechanical properties of osteosynthesis were adjudged superior to stand-alone cementoplasty in each case. Cannulated screws were placed under combined CT and fluoroscopic guidance with complementary radiofrequency ablation or cementoplasty to optimise local palliation and secure screw fixation, respectively, in two cases. Follow-up was undertaken every few weeks until mortality or most recent appointment. Four pathological fractures were treated in three patients (2 acromion, 1 clavicular, 1 coracoid). Mean size of associated lesion was 2.6 cm (range 1-4.5 cm). Technical success was achieved in all cases (100 %), without complications. Good palliation and restoration of mobility were observed in two cases at 2-3 months; one case could not be followed due to early post-procedural oncologic mortality. Percutaneous image-guided shoulder-girdle osteosynthesis appears technically feasible with good short-term efficacy in this complex patient subset. Further studies are warranted to confirm these promising initial results.

  12. Percutaneous Glycerol Rhizotomy for Trigeminal Neuralgia Using a Single-Plane, Flat Panel Detector Angiography System: Technical Note

    PubMed Central

    ARISHIMA, Hidetaka; KAWAJIRI, Satoshi; ARAI, Hiroshi; HIGASHINO, Yoshifumi; KODERA, Toshiaki; KIKUTA, Ken-ichiro

    2016-01-01

    Percutaneous treatments for trigeminal neuralgia (TN) including glycerol rhizotomy (GR), radiofrequency thermocoagulation (RT), and balloon compression (BC) are effective for patients with medical comorbidities and risk factors of microvascular decompression (MVD). These procedures are usually performed under fluoroscopy. Surgeons advance the needle to the trigeminal plexus through the foramen ovale while observing landmarks of fluoroscopic images; however, it is sometimes difficult to appropriately place the needle tip in Meckel’s cave. We present the technical details of percutaneous GR using a single-plane, flat panel detector angiography system to check the needle positioning. When the needle tip may be located near the trigeminal cistern, three-dimensional (3-D) bone images are taken with cone-beam computed tomography (CT). These images clearly show the position of the needle tip in Meckel’s cave. If it is difficult to place it through the foramen ovale, surgeons perform cone beam CT to observe the actual position of the needle tip at the skull base. After confirming the positional relation between the needle tip and foramen ovale, surgeons can advance it in the precise direction. In 10 procedures, we could place the nerve-block needle in about 14.5 minutes on average without complications. We think that our method is simple and convenient for percutaneous treatments for TN, and it may be helpful for surgeons to perform such treatments. PMID:27041633

  13. Percutaneous Glycerol Rhizotomy for Trigeminal Neuralgia Using a Single-Plane, Flat Panel Detector Angiography System: Technical Note.

    PubMed

    Arishima, Hidetaka; Kawajiri, Satoshi; Arai, Hiroshi; Higashino, Yoshifumi; Kodera, Toshiaki; Kikuta, Ken-Ichiro

    2016-05-15

    Percutaneous treatments for trigeminal neuralgia (TN) including glycerol rhizotomy (GR), radiofrequency thermocoagulation (RT), and balloon compression (BC) are effective for patients with medical comorbidities and risk factors of microvascular decompression (MVD). These procedures are usually performed under fluoroscopy. Surgeons advance the needle to the trigeminal plexus through the foramen ovale while observing landmarks of fluoroscopic images; however, it is sometimes difficult to appropriately place the needle tip in Meckel's cave. We present the technical details of percutaneous GR using a single-plane, flat panel detector angiography system to check the needle positioning. When the needle tip may be located near the trigeminal cistern, three-dimensional (3-D) bone images are taken with cone-beam computed tomography (CT). These images clearly show the position of the needle tip in Meckel's cave. If it is difficult to place it through the foramen ovale, surgeons perform cone beam CT to observe the actual position of the needle tip at the skull base. After confirming the positional relation between the needle tip and foramen ovale, surgeons can advance it in the precise direction. In 10 procedures, we could place the nerve-block needle in about 14.5 minutes on average without complications. We think that our method is simple and convenient for percutaneous treatments for TN, and it may be helpful for surgeons to perform such treatments.

  14. The challenge of extraabdominal desmoid tumour management in patients with Gardner's syndrome: radiofrequency ablation, a promising option.

    PubMed

    Cobianchi, Lorenzo; Ravetta, Valentina; Viera, Francesca Torello; Filisetti, Claudia; Siri, Barbara; Segalini, Edoardo; Maestri, Marcello; Dominioni, Tommaso; Alessiani, Mario; Rossi, Sandro; Dionigi, Paolo

    2014-11-27

    Desmoid tumours are benign, myofibroblastic stromal neoplasms common in Gardner's syndrome, which is a subtype of familial adenomatous polyposis characterized by colonic polyps, osteomas, thyroid cancer, epidermoid cysts, fibromas and sebaceous cysts. The primary treatment is surgery, followed by adjuvant radiotherapy, but the local recurrence rate is high, and wide resection can result in debilitating loss of function. We report the case of a 39-year-old man with Gardner's syndrome who had already undergone a total prophylactic colectomy. He developed desmoid tumours localized in the mesenteric root, abdominal wall and dorsal region, which were treated from 2003 through 2013 with several surgical procedures and percutaneous radiofrequency ablation. In 2008 and 2013, RFA was applied under ultrasonographic guidance to two desmoid tumours localized in the dorsal thoracic wall. The outcomes were low-grade pain and one case of superficial skin necrosis, but so far there has been no recurrence of desmoid tumours in these locations. Surgical resection remains the first-line therapy for patients with desmoid tumours, but wide resection may lead to a poor quality of life. Radiofrequency ablation is less invasive and expensive and is a possible therapeutic option for desmoid tumours in patients with Gardner's syndrome.

  15. Delayed bronchobiliary fistula following radiofrequency ablation in a patient with hepatocellular carcinoma: A case report and lesson regarding treatment

    PubMed Central

    ZENG, ZHAOLIN; CAI, MINGYUE; HUANG, WENSOU; HUANG, JINGJUN; CHEN, XIUZHEN; SHAN, HONG; ZHU, KANGSHUN

    2016-01-01

    Bronchobiliary fistula (BBF) is a rare complication of radiofrequency ablation (RFA) of hepatocellular carcinoma. The rupture of a biloma following RFA may result in the development of BBF, with their early detection and timely management important in the prevention of BBF. The current study presents a case of BBF, which developed at 17 months after radiofrequency ablation (RFA), due to biloma rupture in a patient with hepatocellular carcinoma. Despite the percutaneous drainage of the biloma following BBF, the persistent fever did not resolve due to biliary infection. Finally, an extensive surgical intervention was performed. The magnetic resonance imaging (MRI) scans that had been performed following RFA were reviewed, and it was found that the biloma and increased bile leakage had presented prior to biloma rupture. For that reason, it is advised that patients who present with biloma following RFA should receive regular follow-up MRI scans. Biloma enlargement could be a predictor for the development of BBF; therefore, timely drainage of an enlarging biloma may be able to prevent this complication. PMID:27123093

  16. Endoluminal radiofrequency ablation of the long saphenous vein (VNUS closure) -- a minimally invasive management of varicose veins.

    PubMed

    Fassiadis; Holdstock; Whiteley

    2003-03-01

    This report describes our clinical experience with the VNUS closure. This is a percutaneous catheter-based procedure in which the vein is ablated from within by resistive heating. We performed the UK's first radiofrequency closure without a high tie in March 1999. Between then and March 2000, 40 patients (35:5 F:M, age 22-92, mean 45.1 years) had 59 legs treated. All operations were for varicose veins, eight legs were recurrent, four legs had concomitant ulceration and three legs were treated with additional subfascial endoscopic perforator ligation (SEPS). Only one treatment failure occurred in our series. In all the other successfully treated limbs the long saphenous vein remained without flow on Duplex scan evaluation during our 1 year follow-up. All patients were fully mobile within 12 hours and all patients returned to their daily activities or to work within 72 hours. On questioning, no patient reported pain related to the thigh procedure. This new technique of radiofrequency ablation provides a minimal access alternative to the classical high saphenous tie and strip. Our results to date suggest that this procedure results in minimal post-operative pain and allows early return to normal activities.

  17. Radiofrequency ablation therapy combined with cementoplasty for painful bone metastases: initial experience.

    PubMed

    Toyota, Naoyuki; Naito, Akira; Kakizawa, Hideaki; Hieda, Masashi; Hirai, Nobuhiko; Tachikake, Toshihiro; Kimura, Tomoki; Fukuda, Hideki; Ito, Katsuhide

    2005-01-01

    The purpose of this study was to assess the efficacy and safety of percutaneous radiofrequency (RF) ablation therapy combined with cementoplasty under computed tomography and fluoroscopic guidance for painful bone metastases. Seventeen adult patients with 23 painful bone metastases underwent RF ablation therapy combined with cementoplasty during a 2-year period. The mean tumor size was 52 x 40 x 59 mm. Initial pain relief, reduction of analgesics, duration of pain relief, recurrence rate of pain, survival rate, and complications were analyzed. The technical success rate was 100%. Initial pain relief was achieved in 100% of patients (n=17). The mean VAS scores dropped from 63 to 24 (p<0.001) (n=8). Analgesic reduction was achieved in 41% (7 out of 17 patients). The mean duration of pain relief was 7.3 months (median: 6 months). Pain recurred in three patients (17.6%) from 2 weeks to 3 months. Eight patients died and 8 patients are still alive (a patient was lost to follow-up). The one-year survival rate was 40% (observation period: 1--30 months). No major complications occurred, but one patient treated with this combined therapy broke his right femur 2 days later. There was transient local pain in most cases, and a hematoma in the psoas muscle (n=1) and a hematoma at the puncture site (n=1) occurred as minor complications. Percutaneous RF ablation therapy combined with cementoplasty for painful bone metastases is effective and safe, in particular, for bulky tumors extending to extraosseous regions. A comparison with cementoplasty or RF ablation alone and their long-term efficacies is needed.

  18. Healing after arterial dilatation with radiofrequency thermal and nonthermal balloon angioplasty systems.

    PubMed

    Kaplan, J; Barry, K J; Connolly, R J; Nardella, P C; Hayes, L L; Lee, B I; Waller, B F; Becker, G J; Callow, A D

    1993-01-01

    Thermal balloon angioplasty has been proposed as a means of reducing acute and delayed reclosure of arteries after percutaneous transluminal balloon angioplasty. A radiofrequency (rf) balloon catheter was used to perform thermal balloon angioplasty on canine arteries in vivo. The histologic appearance of rf-treated sites was compared with that of control sites treated by conventional percutaneous transluminal angioplasty. Acutely, rf-treated sites showed a reduced medial cellularity with preservation of internal elastic lamina except at the transitional zone between thermal injury and normal artery, where localized internal elastic lamina disruption was found. Nonthermal sites showed generalized disruption of internal elastic lamina and normal medial cellularity. Both thermal and nonthermal sites displayed a return of intimal cover commencing at 1 to 2 weeks and completed by 4 weeks. Diffuse myointimal hyperplasia appeared by 2 weeks after injury at breaks in the internal elastic lamina along the nonthermal vessels but was localized to the transitional zone in thermal injury sites. In rf-treated vessels, repopulation of the acellular thermally modified media had commenced by 4 weeks, and by 8 weeks the media was diffusely repopulated by spindle-shaped cells resembling smooth muscle cells lying between and aligned with preserved connective tissue laminae. Overall, the distribution and extent of the proliferative response after rf thermal balloon angioplasty were less than those seen after nonthermal balloon angioplasty. Thermal sites, which underwent reintimalization before medial cells returned, were considerably less prone to the development of myointimal hyperplasia. These results suggest that this modality may have beneficial effects on arterial healing after angioplasty.

  19. Novel Single Puncture Approach for Simplicity 3 Sacral Plexus Radiofrequency Ablation: Technical Note.

    PubMed

    Gilligan, Jeffrey; Shih, Jennifer C; Cai, Viet L; Hirsch, Joshua A; Rodrigues, Christopher; Irani, Zubin D

    2016-05-01

    Radiofrequency (RF) ablation of the lateral sacral plexus has been used for the treatment of sacroiliac joint pain including as an adjunct to other palliative therapies for the treatment of painful osseous metastasis. The treatment goal is targeted ablation of the dorsal lateral branches of S1-S4. Though several techniques have been described, the Simplicity III (Neurotherm, Middleton, MA) system allows for ablation to be achieved with a single RF probe by utilizing a multi-electrode curved RF probe to create a continuous ablation line across all sacral nerves. In the standard approach, there is sequential introduction of a spinal needle along the desired ablation tract for local anesthesia followed by separate placement of the ablation probe. Though fluoroscopic guidance is utilized, multiple needle passes increase the risk of complication such as bowel perforation or probe insertion through a neural foramen. It may also extend procedure time and increase radiation dose. We illustrate a technique for Simplicity III RF ablation of the dorsal sacral plexus using a modified Seldinger approach for treatment of a patient with sacroiliac joint pain due to osseous renal cell carcinoma metastasis. The desired ablation tract is initially anesthetized via a hollow micropuncture needle. The needle is then exchanged for a peelaway sheath. The RF probe is inserted through the peelaway sheath thus ensuring the probe is placed precisely along the previously anesthetized tract allowing the procedure to be completed using a single percutaneous puncture. We believe that this approach decreases the risks of bowel perforation, patient discomfort as a result of multiple percutaneous punctures, and procedure time. Simplicity 3, sacral plexus ablation, image-guided approach, modified Seldinger, chronic sacral pain, thin wall introducer needle.

  20. Radiofrequency Ablation Therapy Combined with Cementoplasty for Painful Bone Metastases: Initial Experience

    SciTech Connect

    Toyota, Naoyuki Naito, Akira; Kakizawa, Hideaki; Hieda, Masashi; Hirai, Nobuhiko; Tachikake, Toshihiro; Kimura, Tomoki; Fukuda, Hideki; Ito, Katsuhide

    2005-06-15

    The purpose of this study was to assess the efficacy and safety of percutaneous radiofrequency (RF) ablation therapy combined with cementoplasty under computed tomography and fluoroscopic guidance for painful bone metastases. Seventeen adult patients with 23 painful bone metastases underwent RF ablation therapy combined with cementoplasty during a 2-year period. The mean tumor size was 52 x 40 x 59 mm. Initial pain relief, reduction of analgesics, duration of pain relief, recurrence rate of pain, survival rate, and complications were analyzed. The technical success rate was 100%. Initial pain relief was achieved in 100% of patients (n = 17). The mean VAS scores dropped from 63 to 24 (p < 0.001) (n = 8). Analgesic reduction was achieved in 41% (7 out of 17 patients). The mean duration of pain relief was 7.3 months (median: 6 months). Pain recurred in three patients (17.6%) from 2 weeks to 3 months. Eight patients died and 8 patients are still alive (a patient was lost to follow-up). The one-year survival rate was 40% (observation period: 1-30 months). No major complications occurred, but one patient treated with this combined therapy broke his right femur 2 days later. There was transient local pain in most cases, and a hematoma in the psoas muscle (n = 1) and a hematoma at the puncture site (n = 1) occurred as minor complications. Percutaneous RF ablation therapy combined with cementoplasty for painful bone metastases is effective and safe, in particular, for bulky tumors extending to extraosseous regions. A comparison with cementoplasty or RF ablation alone and their long-term efficacies is needed.

  1. Combined Therapy of Radiofrequency Ablation and Ethanol Injection of Rabbit Liver: An In Vivo Feasibility Study

    SciTech Connect

    Lee, Jeong Min; Lee, Young Hwan; Kim, Young Kon; Kim, Sang Won; Kim, Chong Soo

    2004-03-15

    Our purpose was to compare the effects of percutaneous radiofrequency ablation (RFA) combined with percutaneous ethanol injection (PEI) on the extent of ablation in in vivo rabbit liver tissue as compared with either therapy alone. Twenty-two New Zealand white rabbits were included in this study and allocated into three groups: group A: conventional RFA (n = 6); group B: PEI (n = 6); group C: combined RFA and PEI (n = 10). For combined RFA and PEI, under ultrasound guidance, 1 mL of absolute ethanol was injected into the target area of the liver parenchyma through a 21-gauge Chiba needle before performing RFA. RFA was performed using a 17- gauge internally cooled electrode with 1-cm active tip, and RF energy (30 W) was applied for 3 minutes, with or without ethanol injection. After RFA or PEI, contrast-enhanced computed tomography and CT-pathologic correlation were performed. The short- axis and long-axis diameters of thermal lesions of each group were compared. All procedures were technically successful and a total of 38 lesions were produced. The mean short-axis and long-axis diameter of the coagulation necrosis in rabbits of group C (combination of RFA and PEI), were significantly larger than those of other groups: group A: 10.3 {+-} 2 mm and 11.4 {+-} 2 mm; group B: 3.1 {+-} 1 mm and 4.3 {+-} 2 mm; group C: 12.8 {+-} 3 mm and 17.8 {+-} 6 mm (p < 0.05). On contrast-enhanced CT scan, the lesions of rabbits of the group C appeared to be more frequently irregular compared to those of group A (20% in group A vs. 67% in group C). There were three complications including two localized hematomas and one cardiopulmonary failure. Combined RFA and PEI could increase the dimension of coagulation necrosis without increasing complications and therefore, may be successfully used for treating larger lesions.

  2. Radiofrequency ablation of lung metastases close to large vessels during vascular occlusion: preliminary experience.

    PubMed

    de Baere, Thierry; Robinson, Joey Marie; Rao, Pramod; Teriitehau, Christophe; Deschamps, Frederic

    2011-06-01

    To report an initial prospective evaluation of the technical feasibility, efficacy, and safety of combining percutaneous temporary balloon occlusion (PBO) of a large pulmonary artery adjacent to a metastatic lung tumor treated with percutaneous radiofrequency (RF) ablation. In six patients, lung RF ablation with a multitined, expandable electrode with simultaneous PBO via femoral access was attempted with the use of digital angiography and multidetector computed tomography (CT). Follow-up imaging was obtained immediately after treatment, at 1-2 days, and at 2, 6, 9, and 12 months; positron emission tomography/CT was performed at 4 months. Metastases targeted measured 17-37 mm (22 ± 8) and were in contact with a pulmonary artery 3-5 mm. Temporary occlusion of the pulmonary arterial branch in contact with the tumor was technically possible in five of six patients. Postablation CT scans obtained within 2 days of the procedure showed ablation zones measuring 37-57 mm (47 ± 8) in their shortest diameter. Three patients developed lung infarction within 1 month after RF ablation, and two had to be readmitted. At 3 months after the procedure, four patients had persistent occlusion of the balloon-occluded vessel. No uptake was demonstrated 4 months after ablation; at 12 months, all tumors showed complete ablation on CT. RF ablation of lung tumors with PBO is a feasible technique, but it induces atelectasia and long-lasting vascular occlusion responsible for a high rate of readmission. The results of this small study warrant careful further exploration of the benefits of the technique, compared with RF ablation without PBO or other methods of ablative therapy. Copyright © 2011 SIR. Published by Elsevier Inc. All rights reserved.

  3. Hemobilia and other complications caused by percutaneous ultrasound-guided liver biopsy.

    PubMed

    Zhou, Hai-Bo

    2014-04-07

    Hemobilia accounts for approximately 3% of all major percutaneous liver biopsy complications, and rarely results from arterioportal fistula. We report a patient who suffered from four complications over 11 d after ultrasound-guided percutaneous liver biopsy: hemobilia, acute pancreatitis, acute cholecystitis, and multiple stomach ulcers. Digital subtraction angiography was done after consultation with doctors, and showed obvious arteriovenous fistula of the right liver. The hepatic artery was selected and embolized by spring orbs. The active bleeding was stopped after embolization of the hepatic artery. The patient was discharged home on day 12 after embolization and remained well.

  4. Hemobilia and other complications caused by percutaneous ultrasound-guided liver biopsy

    PubMed Central

    Zhou, Hai-Bo

    2014-01-01

    Hemobilia accounts for approximately 3% of all major percutaneous liver biopsy complications, and rarely results from arterioportal fistula. We report a patient who suffered from four complications over 11 d after ultrasound-guided percutaneous liver biopsy: hemobilia, acute pancreatitis, acute cholecystitis, and multiple stomach ulcers. Digital subtraction angiography was done after consultation with doctors, and showed obvious arteriovenous fistula of the right liver. The hepatic artery was selected and embolized by spring orbs. The active bleeding was stopped after embolization of the hepatic artery. The patient was discharged home on day 12 after embolization and remained well. PMID:24707158

  5. An algorithm for use of prasugrel (effient) in patients undergoing cardiac catheterization and percutaneous coronary intervention.

    PubMed

    Marchini, Julio; Morrow, David; Resnic, Frederic; Manica, Andre; Kirshenbaum, James; Cannon, Christopher; Croce, Kevin

    2010-12-01

    An algorithm for use of Prasugrel (Effient) in patients undergoing cardiac catheterization and percutaneous coronary intervention at the Brigham and Women's Hospital is presented. Our algorithm, which is in the process of being implemented, is consistent with published and generally accepted standards of care and is based on data from the pivotal Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition with Prasugrel-Thrombolysis in Myocardial Infarction (TRITON-TIMI) 38, which compared clopidogrel with prasugrel in acute coronary syndrome patients undergoing percutaneous coronary intervention. Areas of focus include analysis of the benefit of prasugrel over clopidogrel in acute coronary syndrome patients and appropriate selection of patients for prasugrel treatment.

  6. Emergency percutaneous tracheostomy in a severely burned patient with upper airway obstruction and circulatory arrest.

    PubMed

    Schlossmacher, Pascal; Martinet, Olivier; Testud, Richard; Agesilas, Fabrice; Benhamou, Léon; Gauzëre, Bernard Alex

    2006-02-01

    We report the life-saving use of Griggs percutaneous tracheostomy in an arrested patient with complex upper airway obstruction, as a result of burns, smoke injuries and iterative tracheal intubation attempts. The technique was performed blindly at bedside to treat an acute episode of failed ventilation and intubation and cardiac arrest in a patient with altered neck anatomy. The intervention salvaged the situation, leaving a definitive airway. The feasibility of using an emergency Griggs percutaneous tracheostomy versus cricothyroidotomy is suggested in selected cases.

  7. Percutaneous umbilical cord blood sampling - series (image)

    MedlinePlus

    ... your doctor may recommend percutaneous umbilical cord blood sampling (PUBS), which is performed at 18 weeks' gestation. ... it connects to the umbilical cord determine which method your doctor uses. If the placenta is attached ...

  8. Shaving effects on percutaneous penetration: clinical implications.

    PubMed

    Hamza, Muhammad; Tohid, Hassaan; Maibach, Howard

    2015-01-01

    Human/animal shaving biology. To assess the effect of shaving on percutaneous penetration and skin function. We screened 500+publications in Pub Med, Scopus, Cochrane Library and pertinent journals out of which only 17 were deemed relevant. Terms for searches included shaving and skin, percutaneous penetration and shaving, skin absorption and shaving, absorption of dyes and shaving, skin penetration, effects of shaving and absorption, shave and dyes, axillary shaving and stratum corneum, shaving and breast cancer, shaving and infections, etc. Shaving appears to have an exaggerated effect on percutaneous absorption; however, some studies do not support this evidence. Shaving enhances percutaneous penetration of some chemicals; however this effect is species and chemical specific. Further investigations of chemicals of varying physio-chemical properties are mandated before a generalized theory can be promulgated.

  9. Cangrelor for treatment during percutaneous coronary intervention.

    PubMed

    Oestreich, Julie H; Dobesh, Paul P

    2014-03-01

    Dual antiplatelet therapy consisting of aspirin and a P2Y12-receptor antagonist is important for preventing major adverse cardiovascular events in patients managed with percutaneous coronary intervention (PCI). The current P2Y12-receptor antagonists are only available for oral administration and exhibit a delayed onset of action. Furthermore, several days are required for platelet function to return to normal following cessation of therapy. Cangrelor is an intravenous ATP analog that directly, selectively and reversibly inhibits P2Y12 receptors on platelets. A 30-μg/kg bolus dose followed by a 4-μg/kg per minute continuous infusion of cangrelor achieves peak concentration and maximal platelet inhibition within minutes of administration. Cangrelor also demonstrates a fast offset as normal platelet function is restored 1-2 h after cessation of the infusion. Three large, double-blind, randomized trials - CHAMPION PLATFORM, CHAMPION PCI and CHAMPION PHOENIX - assessed the efficacy and safety of cangrelor compared with clopidogrel (during or immediately after PCI) or placebo in the setting of PCI. In the most recent CHAMPION PHOENIX trial, cangrelor was superior to clopidogrel for preventing adverse cardiovascular events with no significant increase in major bleeding. Based on the clinical trial results combined with unique properties such as intravenous administration and fast onset and offset, cangrelor may provide benefit in certain patients undergoing PCI.

  10. An investigation on the effect of improved X-rays-guided radiofrequency thermocoagulation denervation on lumbar facet joint syndrome.

    PubMed

    Zhou, Qin; Zhou, Fang; Wang, Long; Liu, Kang

    2016-09-01

    This study aims to observe the clinical efficacy and feasibility of improved X-rays-guided radiofrequency thermocoagulation denervation for treating low back pain secondary to lumbar facet joint syndrome (LFJS). Eighty LFJS patients were randomly assigned into two groups: the denervation group (n=40), treated with percutaneous radiofrequency thermocoagulation denervation on the lumbar facet joint, and the control group (n=40), injected with betamethasone and lidocaine into the lumbar facet joint. All patients underwent pain scoring using the visual analogous scale (VAS) before treatment, and again at 30 min, 1 d, 1 week, 1 month, and 6 months after treatment. The Schober index was also evaluated at 1 week, 1 month, and 6 months after treatment. The efficacy and adverse effects were also recorded. The denervation group had significantly lower VAS scores at each time point than before treatment (P<0.01). The VAS scores in the control group at 30min, 1d, 1 week, and 1 month after treatment were also significantly lower, but they returned to the pre-treatment level at 6 months after treatment. The VAS scores in the denervation group were significantly lower than that in the control group at 1 month and at 6 months after treatment (P<0.05 and P<0.01), whereas the Schober index was significantly higher (P<0.01). Moreover, the excellent to good efficacy rate in the denervation group was higher than that in the control group (P<0.01). The patients in both treatments had no side effects. Improved X-rays-guided radiofrequency thermocoagulation denervation is an effective, minimally invasive and convenient method for treating low back pain secondary to lumbar facet syndrome. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Ultrasound-Guided Pulsed Radiofrequency Application via the Pterygopalatine Fossa: A Practical Approach to Treat Refractory Trigeminal Neuralgia.

    PubMed

    Nader, Antoun; Bendok, Bernard R; Prine, Jeremy J; Kendall, Mark C

    2015-01-01

    Although pharmacological therapy is the primary treatment modality for trigeminal neuralgia associated pain, ineffective analgesia and dose limiting side effects often prompt patients to seek alternative pharmacological solutions such as interventional nerve blockade. Blockade of the Gasserian ganglion or its branches is an effective analgesic procedure for trigeminal neuralgia, traditionally performed using fluoroscopy or CT imaging. Ultrasonography allows point of care and real time visualization of needle placement within the surrounding anatomical structures. The use of ultrasonography with pulsed radiofrequency therapy for trigeminal neuralgia has not been reported. Our case is a 66-year-old male suffering from trigeminal neuralgia for 4 years that was refractory to pharmacologic therapy. Neurological examination was normal with no sensory deficit. Imaging showed no vascular compression or mass involving the trigeminal nerve. A diagnostic ultrasound-guided trigeminal nerve block via the pterygopalatine fossa with 4 mL of bupivacaine 0.25% and 4 mg dexamethasone provided immediate pain relief (100%) with sustained analgesia >50% at 2 weeks. Pain relief was not sustained at one month, with return to pretreatment symptoms. A series of injections were performed with similar intermittent analgesic effectiveness. The decision was made that the patient was a suitable candidate for pulsed radiofrequency application in the pterygopalatine fossa. We successfully used an alternative approach through the pterygopalatine fossa to treat trigeminal neuralgia using ultrasound guidance in an office setting. Our case demonstrates the utility of ultrasound-guidance pulsed radiofrequency treatment in the pterygopalatine fossa as a potential alternative to other percutaneous techniques for patients with medical refractory trigeminal neuralgia.

  12. Percutaneous Therapies for Peripheral Artery Disease.

    PubMed

    Shishehbor, Mehdi H; Jaff, Michael R

    2016-12-13

    Percutaneous therapies for peripheral artery disease continue to evolve with new techniques and devices. Although guidelines-recommended therapies have impacted cardiovascular morbidity and mortality, endovascular interventions have been shown to reduce limb pain, improve quality of life, and prolong walking distance for those with claudication and to reduce amputation rates among those with critical limb ischemia. Novel devices such as drug-eluting stents and drug-coated balloons have improved patency for moderate-length lesions, whereas others allow treatment of heavily calcified and tortuous segments. New adjunctive devices to cross lesions and reduce or modify associated plaque have also been developed, although level 1 data regarding their efficacy are sparse. There has also been a better mechanistic understanding of lower extremity endovascular treatment using tools such as intravascular ultrasound. This information has highlighted the need for better stent size selection for the femoropopliteal arterial segments and larger balloon diameters for the tibial arteries. Moreover, a wound perfusion approach with direct in-line flow, the so-called angiosome approach, and reconstruction of the pedal loop have been advocated for improved wound healing. Technical advances such as the tibiopedal access and reentry methods have allowed crossing of lesions that were considered no option for the endovascular approach in the past. Collectively, there has been increased awareness, interest, and commitment by various specialty societies and organizations to advance the treatment of peripheral artery disease and critical limb ischemia. This is also evident by the recent coalition of 7 professional societies and organizations that represented >150 000 allied health professionals and millions of patients with peripheral artery disease at the 2015 Centers for Medicaid and Medicare Services Medicare Evidence Development and Coverage Analysis Committee meeting. The percutaneous

  13. Prone and supine percutaneous nephrolithotomy.

    PubMed

    Lucarelli, G; Breda, A

    2013-06-01

    Since the first successful stone extraction through a nephrostomy in 1976, percutaneous nephrolithotomy (PCNL) has became the preferred procedure especially for treatment of large, complex and staghorn calculi. For decades this method has been performed with the patient in the prone position. More recently, particular interest has been taken on supine PCNL due to less anestesiological risks and the possibility of simultaneous anterograde and retrograde access to the whole urinary tract. Although many retrospective studies have been published, only two prospective trials comparing the two positions are reported in the literature. The best access to PCNL represents still a controversial issue. The overall experience reported in literature indicates that each modality is equally feasible and safe. Therefore, to date the surgeon's preference is the prime indication to one access over the other.

  14. [Percutanous dilation tracheotomy: our experience].

    PubMed

    Domènech, I; Mateu, T; Cisa, E; Juan, A; Gil, E; Palau, M; Dicenta, M

    2004-01-01

    Percutaneous dilation Tracheotomy (PDT) is becoming a popular alternative to surgical tracheotomy. In our hospital, we recently adopted the use of the PDT in intensive care unit patients. The objective [corrected] of this investigation is to characterize and quantify the rate of complications for PDT. A prospective study of 60 PDT performed at different intesive care units, betweem September 2002 to July 2003. The intraoperative time for PDT was 8 minutes. Complications included 6 cases of mild intraoperative hemorrhage, 1 case of moderate intraoperative hemorrhage, 4 cases of mild postoperative hemorrhage and 1 case of subcutaneous emphysema. PDT is a good alternative to surgical tracheotomy and should be added to the otolaryngologists armamentarium of surgical airway procedures.

  15. Percutaneous versus Femoral Cutdown Access for Endovascular Aneurysm Repair

    PubMed Central

    Buck, Dominique B.; Karthaus, Eleonora G.; Soden, Peter A.; Ultee, Klaas H. J.; van Herwaarden, Joost A.; Moll, Frans L.; Schermerhorn, Marc L.

    2015-01-01

    Objective Prior studies suggest that percutaneous access for endovascular abdominal aortic aneurysm repair (pEVAR) offers significant operative and post-operative benefits compared to femoral cutdown (cEVAR). National data on this topic, however, are limited. We compared patient selection and outcomes for elective pEVAR and cEVAR. Methods We identified all patients undergoing either pEVAR (bilateral percutaneous access whether successful or not) or cEVAR (at least one planned groin cutdown) for abdominal aortic aneurysms (AAA), from January 2011 to December 2013 in the Targeted Vascular dataset from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database. Emergent cases, ruptures, cases with an iliac conduit, and cases with a preoperative wound infection were excluded. Groups were compared using chi-square test or t-test or the Mann-Whitney test where appropriate. Results 4112 patients undergoing elective EVAR were identified; 3004 cEVAR (73%) and 1108 pEVAR (27%). Of all EVAR patients 26% had bilateral percutaneous access, 1.0% had attempted percutaneous access converted to cutdown (4% of pEVARs), while the remainder had a planned cutdown, 63.9% bilateral, and 9.1% unilateral. There were no significant differences in age, gender, aneurysm diameter or prior open abdominal surgery. Patients undergoing cEVAR were less likely to have congestive heart failure (1.5% vs. 2.4%, P=0.04) but more likely to undergo any concomitant procedure during surgery (32% vs. 26%, P<.01) than patients undergoing pEVAR. Postoperatively, pEVAR patients had shorter operative time (mean 135 vs. 152 minutes, P<.01), shorter length of stay (median 1 day vs. 2 days, P<.01), and fewer wound complications (2.1% vs. 1.0%, P=0.02). On multivariable analysis the only predictor of percutaneous access failure was performance of any concomitant procedure (OR 2.0, 95% CI 1.0–4.0, P=0.04). Conclusions Currently, 1 in 4 patients treated at Targeted Vascular

  16. Role of radiofrequency denervation in lumbar zygapophyseal joint synovitis in baseball pitchers: a clinical experience.

    PubMed

    Vad, Vijay B; Cano, William G; Basrai, Dilshaad; Lutz, Gregory E; Bhat, Atul L

    2003-07-01

    Lumbar zygapophyseal joints have long been considered a source of low back pain with or without leg pain. The objective of this prospective study was to investigate the therapeutic effectiveness of lumbar zygapophyseal joint radiofrequency denervation (RFD) followed by physical therapy, for the treatment of refractory lumbar zygapophyseal joint mediated low back pain secondary to lumbar zygapophyseal joint synovitis, in baseball pitchers. Participants included twelve male baseball pitchers with a diagnosis of lumbar zygapophyseal joint synovitis mediated low back pain and a subsequent difficulty in pitching. These athletes underwent a trial of treatment, including oral anti-inflammatory medication, physical therapy, osteopathic manipulations, and fluoroscopically guided intra-articular zygapophyseal joint injection utilizing steroid and local anesthetic agent. Failure to progress led to these athletes receiving percutaneous, fluoroscopically-guided, radiofrequency denervation of the bilateral L 4-L5 and L5-S1 zygapophyseal joints. A good response to a diagnostic medial branch block was a prerequisite for RFD treatment. In all cases, the medial branch above and below the involved level was treated. Post procedure, all athletes participated in a phased physical therapy program followed by a progressive return to pitching. Success was defined as the ability to return to pre-procedure level of baseball pitching combined with greater than 50% low back pain reduction. Pre- and post-RFD, Visual Analog (Numeric) Scale (VAS) and Roland-Morris (R-M) tests were administered. Ten out of 12 (83%) athletes were able to return to pitching at a level attained prior to RFD. All 12 patients, experienced statistically significant low back pain relief, with a mean pre-RFD VAS of 8.4; mean post-RFD VAS of 1.7; mean pre-RFD R-M score of 12.3; and mean post-RFD R-M score of 22.3. In conclusion, athletes, experiencing lumbar zygapophyseal joint mediated low back pain secondary to

  17. Seizure Freedom After Limited Hippocampal Radiofrequency Thermocoagulation.

    PubMed

    Li, Han-Tao; Lee, Ching-Yi; Lim, Siew-Na; Chang, Chun-Wei; Lee, Shih-Tseng; Wu, Tony

    2016-12-01

    Surgical interventions are often used for freedom from seizure in patients with drug-resistant mesial temporal lobe epilepsy. A patient with seizure foci in the left mesiotemporal region underwent limited-size stereotactic radiofrequency thermocoagulation (RF-TC) over the left hippocampus. A 37-year-old woman with febrile convulsion in her childhood was admitted to our neurologic department with complex partial seizure with secondary generalization. Electroencephalography showed epileptogenic focus mainly from the left mesiotemporal region, and magnetic resonance imaging confirmed a left hippocampal atrophy. Because of failure to control seizure after use of several antiepileptic drugs, drug-resistant mesial temporal lobe epilepsy was diagnosed. RF-TC was done in the left hippocampus. Unique features of our technique include intraoperative electroencephalography recordings directly from electrodes on the left hippocampus, an aura sensation provoked during the low-temperature test thermocoagulation, and therapeutic thermocoagulation performed via a Radionics radiofrequency lead. In the 16-week period following the surgery, the patient experienced no seizure attacks and no significant postoperative adverse effects or memory impairments. Compared with other reports using RF-TC, our case demonstrates a 1-step minimally invasive surgery that reduces hippocampal volume loss, shortens the length of hospital stay, decreases the occurrence of postoperative infection, and achieves good outcomes for epilepsy control. Favorable seizure control was achieved with minimally invasive RF-TC. Further use of this technique is warranted in cases of drug-resistant mesial temporal lobe epilepsy. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Radio-frequency scanning tunnelling microscopy.

    PubMed

    Kemiktarak, U; Ndukum, T; Schwab, K C; Ekinci, K L

    2007-11-01

    The scanning tunnelling microscope (STM) relies on localized electron tunnelling between a sharp probe tip and a conducting sample to attain atomic-scale spatial resolution. In the 25-year period since its invention, the STM has helped uncover a wealth of phenomena in diverse physical systems--ranging from semiconductors to superconductors to atomic and molecular nanosystems. A severe limitation in scanning tunnelling microscopy is the low temporal resolution, originating from the diminished high-frequency response of the tunnel current readout circuitry. Here we overcome this limitation by measuring the reflection from a resonant inductor-capacitor circuit in which the tunnel junction is embedded, and demonstrate electronic bandwidths as high as 10 MHz. This approximately 100-fold bandwidth improvement on the state of the art translates into fast surface topography as well as delicate measurements in mesoscopic electronics and mechanics. Broadband noise measurements across the tunnel junction using this radio-frequency STM have allowed us to perform thermometry at the nanometre scale. Furthermore, we have detected high-frequency mechanical motion with a sensitivity approaching approximately 15 fm Hz(-1/2). This sensitivity is on par with the highest available from nanoscale optical and electrical displacement detection techniques, and the radio-frequency STM is expected to be capable of quantum-limited position measurements.

  19. Neurohumoral indicators of efficacy radiofrequency cardiac denervation

    SciTech Connect

    Evtushenko, A. V. Evtushenko, V. V.; Saushkina, Yu. V.; Gusakova, A. M.; Suslova, T. E.; Dymbrylova, O. N.; Smyshlyaev, K. A.; Kurlov, I. O.; Lishmanov, Yu. B.; Anfinogenova, Ya. D.; Sergeevichev, D. S.; Bykov, A. N.; Syryamkin, V. I.; Kistenev, Yu. V.; Lotkov, A. I.; Pokushalov, E. A.

    2015-11-17

    In this study, we compared pre- and postoperative parameters of the cardiac sympathetic innervation. The aim of the study was to examine the approaches to evaluating the quality of radiofrequency (RF)-induced cardiac denervation by using non-invasive and laboratory methods. The study included 32 people with long-lasting persistent atrial fibrillation (AF). The patients were divided into 2 groups according to the objectives of the study: group 1 (main) - 21 patients with mitral valve diseases, which simultaneously with radiofrequency ablation (RFA) AF carried out on the effects of the paraganglionic nervous plexuses by C. Pappone (2004) and N. Doll (2008) schemes. The second group (control) contained 11 patients with heart diseases in sinus rhythm (the RF denervation not been performed). All patients, who underwent surgical treatment, were received examination of cardiac sympathetic tone by using {sup 123}I-MIBG. All of them made blood analysis from ascending aorta and coronary sinus to determine the level of norepinephrine and its metabolites before and after cardiac denervation. Data of radionuclide examination are correlating with laboratory data.

  20. [Arthroscopic therapy of Baker's cyst with radiofrequency].

    PubMed

    Liu, Yu-jie; Wang, Zhi-gang; Li, Zhong-li; Cai, Xu; Zhang, Wen-tao; Hao, Li-bo; Chen, Ji-ying; Gao, Li

    2004-02-22

    To explore the feasibility of arthroscopic therapy of Baker's cysts with radiofrequency. Since Feb. 2000 to Oct. 2002 a surgical arthroscopic treatment for popliteal cyst in a series of 21 patients. Men 14 and female 7, the age from 45 to 66 year. To do CT scan 11 and MR in 8. To insert a arthroscope to Baker's cyst, and inject salline in the visceral layer of capsule under the arthroscope, so that remove of the capsule easily. The radiofrequency to clear the capsule of cyst and hemostasia. All of the cases studied, a connection between joint space and cyst was found in 13 cases. The popliteal cyst was found to be almost invariably associated with other knee disorders. Follow-up in all of the case. No nerve and blood vessel injure, no infection in this group. The function is well include 3 cases relapsed after re-operation by arthroscope debridement. Surgical arthroscopic therapy of Baker's cysts is safety and reliable; To removal of capsule integrity and repair of all intraarticular lesions and sealing of the junction between Baker's cyst and the dorsal recessus of the knee joint for preventing recurrent are very important.

  1. Neurohumoral indicators of efficacy radiofrequency cardiac denervation

    NASA Astrophysics Data System (ADS)

    Evtushenko, A. V.; Evtushenko, V. V.; Saushkina, Yu. V.; Lishmanov, Yu. B.; Pokushalov, E. A.; Sergeevichev, D. S.; Gusakova, A. M.; Suslova, T. E.; Dymbrylova, O. N.; Bykov, A. N.; Syryamkin, V. I.; Kistenev, Yu. V.; Anfinogenova, Ya. D.; Smyshlyaev, K. A.; Lotkov, A. I.; Kurlov, I. O.

    2015-11-01

    In this study, we compared pre- and postoperative parameters of the cardiac sympathetic innervation. The aim of the study was to examine the approaches to evaluating the quality of radiofrequency (RF)-induced cardiac denervation by using non-invasive and laboratory methods. The study included 32 people with long-lasting persistent atrial fibrillation (AF). The patients were divided into 2 groups according to the objectives of the study: group 1 (main) - 21 patients with mitral valve diseases, which simultaneously with radiofrequency ablation (RFA) AF carried out on the effects of the paraganglionic nervous plexuses by C. Pappone (2004) and N. Doll (2008) schemes. The second group (control) contained 11 patients with heart diseases in sinus rhythm (the RF denervation not been performed). All patients, who underwent surgical treatment, were received examination of cardiac sympathetic tone by using 123I-MIBG. All of them made blood analysis from ascending aorta and coronary sinus to determine the level of norepinephrine and its metabolites before and after cardiac denervation. Data of radionuclide examination are correlating with laboratory data.

  2. Removal of discal cyst using percutaneous working channel endoscope via transforaminal route

    PubMed Central

    Kim, Jin-Sung; Choi, Gun; Lee, Choon Dae

    2008-01-01

    Discal cyst is a very rare lesion that can cause refractory low back pain and radiating leg pain. Although there are some reports to remove this lesion, there has been no report of discal cyst removed by percutaneous endoscopic transforaminal approach. Two young patients manifested left gluteal and leg pain due to a discal cyst at L5–S1 level and L4–5 level, respectively. Percutaneous endoscopic transforaminal approach was performed to remove the discal cyst, achieving complete decompression of the nerve root. The symptom was relieved and the patient was discharged the next day. Percutaneous endoscopic transforaminal approach could be a good alternative option in selected cases for the treatment of lumbar discal cyst. PMID:19034535

  3. Outcome review on the percutaneous release of the proximal interphalangeal joint accessory collateral ligaments

    PubMed Central

    Cerovac, Sonja; Stanley, John

    2009-01-01

    The percutaneous release of accessory collateral ligaments was introduced in 1986 as a safe and quick procedure to be attempted before open, more extensive joint release in the treatment of proximal interphalangeal joint flexion contracture. Our study analyzed the long-term results and patient satisfaction following a percutaneous release in 30 joints after a mean follow-up period of 34 months. In one half of cases the preoperative joint flexion deformity was reduced from 78° to 34°. The best results were observed in patients with osteoarthritis and stiff, immobilized joints. In patients with inflammatory arthritides, marked intraoperative correction was maintained rarely, joint contractures recurred early, and patients were unsatisfied. There were no intraoperative complications. Percutaneous release of the accessory collateral ligaments can produce a long lasting correction of the joint contracture, but careful patient selection and strict postoperative rehabilitation are essential for favorable outcome. PMID:21808681

  4. Microwave ablation of hepatocellular carcinoma using a new percutaneous device: preliminary results.

    PubMed

    Poggi, Guido; Montagna, Benedetta; DI Cesare, Pamela; Riva, Giulia; Bernardo, Giovanni; Mazzucco, Mauro; Riccardi, Alberto

    2013-03-01

    Thermal ablative techniques have gained increasing popularity as safe and effective options for patients with unresectable solid malignancies. Microwave ablation has emerged as a relatively new technique with the promise of larger and faster ablation areas without some of the limitations of radiofrequency thermal ablation. Herein, we report our preliminary results on the feasibility and efficacy of thermal ablation for hepatocellular carcinoma (HCC) with a new 2.45-MHz microwave generator. Under ultrasound guidance 194 HCCs in 144 patients were treated through a percutaneous approach. The median diameter of lesions was 2.7 cm (range=2.0-11.0 cm); 68 lesions had a diameter greater than 30 mm. We used a microwave generator (AMICA-GEM, Apparatus for MICrowave Ablation) connected to a 14- or 16-gauge coaxial antenna endowed with a miniaturized sleeve choke to reduce back heating effects and increase the sphericity of the ablated area. Contrast-enhanced computed tomography scan was carried out one month after treatment, and then every three months to assess efficacy. Complete ablation was achieved in 94.3% of the lesions after a mean of 1.03 percutaneous sessions. For small HCCs (diameter <3 cm) complete necrosis was obtained in 100%. Local tumor progressions were found in 10 treated lesions (5.1%) a median of 19.5 months after ablation. Minor complications occurred in 5.1% procedures. No deaths, or other major complications occurred. In our experience, the new device for microwave ablation proved to provide an effective and safe percutaneous ablative method, capable of producing large areas of necrosis.

  5. Pilot experience with transhepatic percutaneous renal cryoablation.

    PubMed

    Malcolm, John B; Gold, Robert; Derweesh, Ithaar H

    2007-07-01

    Percutaneous renal cryoablation has been shown to be a feasible therapeutic option for small renal tumors. Despite advances in equipment design and imaging capabilities, tumor location can present challenges to the percutaneous approach. We present our pilot experience with transhepatic percutaneous cryoablation of right upper-pole renal tumors. Three patients aged 75 to 87 years with American Society of Anesthesiologists scores of III or IV underwent transhepatic percutaneous cryoablation between November 2005 and February 2006. Tumor size ranged from 2 to 5 cm. Cryoprobe placement was guided by CT imaging, and two freeze-thaw cycles were used. Additionally, 60-second freeze-thaw cycles were used to assist with hemostasis in the transhepatic tract. The procedure was completed percutaneously in all cases with the patient under conscious sedation. The procedure time ranged from 67 to 167 minutes. Postoperative pain was managed with minimal use of nonnarcotic oral medications. Although one patient developed a moderate perinephric hematoma and required a blood transfusion, no hepatic complications were manifest. Local treatment failure was evident in one patient with a 5-cm mass showing enhancement at follow-up imaging. Transhepatic access for percutaneous cryoablation of renal tumors is feasible. Limitations include tumor size, as larger tumors may introduce prohibitive risks.

  6. A heart team and multi-modality imaging approach to percutaneous closure of a post-myocardial infarction ventricular septal defect

    PubMed Central

    Iyer, Sunil; Bauer, Thurston; Yeung, Michael; Ramm, Cassandra; Kiser, Andy C.; Caranasos, Thomas G.

    2016-01-01

    Post-infarction ventricular septal defect (PI-VSD) is a devastating complication that carries a high mortality with or without surgical repair. Percutaneous closure is an attractive alternative in select patients though requires appropriate characterization of the PI-VSD as well as careful device and patient selection. We describe a multidisciplinary and multi-modality imaging approach to successful percutaneous closure of a PI-VSD. PMID:27054108

  7. Radiofrequency Ablation in Combination with Embolization in Metachronous Recurrent Renal Cancer in Solitary Kidney after Contralateral Tumor Nephrectomy

    SciTech Connect

    Gebauer, Bernhard Werk, Michael; Lopez-Haenninen, Enrique; Felix, Roland; Althaus, Peter

    2007-07-15

    Purpose. To evaluate the feasibility and safety of minimally invasive, percutaneous techniques in metachronous recurrent renal cell cancers (RCCs) in solitary kidneys. Methods. In 4 patients, recurrent RCC was treated by radiofrequency ablation (RFA) (RITA, StarBurst) alone, and in 2 patients by RFA in combination with superselective transarterial particle-lipiodol embolization using 3 Fr microcatheters. RFA was guided by computed tomography in 5 patients, and by magnetic resonance imaging in 1 patient. Mean tumor diameter was 26.7 mm (range 10-45 mm). All interventions were technically successful; during follow-up 1 patient developed recurrent RCC, which was retreated by RFA after embolization. Results. No major peri- or postprocedural complications occurred. Changes in creatinine (pre- vs. post-intervention, 122 vs. 127 {mu}mol/l) and calculated creatinine clearance (pre- vs. post-intervention, 78 vs. 73 ml/min) after ablation were minimal. Conclusion. In single kidneys, percutaneous, minimally invasive techniques are safe and feasible. In large tumors, or where there are adjacent critical structures, we prefer a combination of embolization and thermal ablation (RFA)

  8. Percutaneous vertebroplasty and interventional tumor removal for malignant vertebral compression fractures and/or spinal metastatic tumor with epidural involvement: a prospective pilot study

    PubMed Central

    Gu, Yi-Feng; Tian, Qing-Hua; Li, Yong-Dong; Wu, Chun-Gen; Su, Yan; Song, Hong-Mei; He, Cheng-Jian; Chen, Dong

    2017-01-01

    Objective The aim of this study was to compare the efficacy of percutaneous vertebroplasty (PVP) and interventional tumor removal (ITR), with PVP alone for malignant vertebral compression fractures and/or spinal metastatic tumor with epidural involvement. Patients and methods A total of 124 patients were selected for PVP and ITR (n = 71, group A) and PVP alone (n = 53, group B). A 14 G needle and guide wire were inserted into the vertebral body, followed by sequential dilatation of the tract until the last cannula reached the anterior portion of the pedicle. Tumors were then ablated with a radiofrequency probe. ITR was performed with marrow nucleus rongeurs, and then cement was injected into the extirpated vertebra. Outcomes were collected preoperatively and at 1, 3 and 6 months and every subsequent 6 months. Results The rates of pain relief and increased mobility at the last follow-up were higher in group A than those in group B (P < 0.05). There were significant differences in visual analog scale (VAS) score and Oswestry disability index (ODI) score at 1, 3 and 6 months, 1 year and >1 year in group A than in group B (P < 0.05). The rates of paraplegia recovery and vertebral stability in group A were higher than those in group B (P < 0.05). Conclusion PVP and ITR proved to be an effective approach for patients with malignant vertebral compression fractures and/or spinal metastatic tumor and provided distinct advantages in pain relief, function recovery and vertebral stability that are comparable to that obtained with PVP alone. PMID:28176970

  9. Impact of monopolar radiofrequency energy on subchondral bone viability.

    PubMed

    Balcarek, Peter; Kuhn, Anke; Weigel, Arwed; Walde, Tim A; Ferlemann, Keno G; Stürmer, Klaus M; Frosch, Karl-Heinz

    2010-05-01

    The purpose of this study was to analyze the impact of monopolar radiofrequency energy treatment on subchondral bone viability. The femoral grooves of six chinchilla bastard rabbits were exposed bilaterally to monopolar radiofrequency energy for 2, 4 and 8 s, creating a total of 36 defects. An intravital fluorescence bone-labeling technique characterized the process of subchondral bone mineralization within the 3 months following exposure to radiofrequency energy and was analyzed by widefield epifluorescence optical sectioning microscopy using an ApoTome. After 2 s of radiofrequency energy exposure, regular fluorescence staining of the subchondral bone was evident in all samples when compared to untreated areas. The depth of osteonecrosis after 4 and 8 s of radiofrequency energy treatment averaged 126 and 942 microm at 22 days (P < .05; P < .01). The 4 s treatment group showed no osteonecrosis after 44 days whereas the depth of osteonecrosis extended from 519 microm at 44 days (P < .01), to 281 microm at 66 days (P < .01) and to 133 microm at 88 days (P < .05) after 8 s of radiofrequency energy application. Though radiofrequency energy may induce transient osteonecrosis in the superficial zone of the subchondral bone, the results of this study suggest that post-arthroscopic osteonecrosis appears to be of only modest risk given the current clinical application in humans.

  10. Endogenous Heat-Shock Protein Induction with or Without Radiofrequency Ablation or Cryoablation in Patients with Stage IV Melanoma.

    PubMed

    Domingo-Musibay, Evidio; Heun, James M; Nevala, Wendy K; Callstrom, Matthew; Atwell, Thomas; Galanis, Evanthia; Erickson, Lori A; Markovic, Svetomir N

    2017-09-01

    Percutaneous thermal ablation combined with in situ granulocyte-macrophage colony-stimulating factor cytokine therapy was technically feasible and well tolerated.No significant clinical or immunologic responses were seen. Melanoma tumor-derived heat-shock proteins (HSPs) and HSP-peptide complexes can elicit protective antitumor responses. The granulocyte-macrophage colony-stimulating factor (GM-CSF) chemokine can also promote uptake and processing by professional antigen presenting cells (APCs). On this basis, we designed a pilot study of percutaneous thermal ablation as a means to induce heat-shock protein vaccination plus GM-CSF to determine safety and preliminary antitumor activity of this combination. This study was designed to assess overall safety of percutaneous ablation combined with GM-CSF for unresectable, metastatic melanoma including uveal and mucosal types. All patients received heat-shock therapy (42°C for 30 minutes), then received one of three treatments: (a) intralesional GM-CSF (500 mcg standard dose); (b) radiofrequency ablation (RFA) + GM-CSF; or (c) cryoablation plus GM-CSF. The primary endpoint of the study was the induction of endogenous HSP70 and melanoma-specific cytotoxic T lymphocytes (CTL). Nine patients (three per study arm) were enrolled. No dose-limiting toxicity was observed as specified per protocol. All patients developed progressive disease and went on to receive alternative therapy. Median overall survival (OS) was 8.2 months (95% confidence interval [CI] 2-17.2). The study was not powered to detect a difference in clinical outcome among treatment groups. Percutaneous thermal ablation plus GM-CSF was well tolerated, technically feasible, and demonstrated an acceptable adverse event profile comparable to conventional RFA and cryoablation. While HSP70 was induced following therapy, the degree of HSP70 elevation was not associated with clinical outcome or induced CTL responses. While percutaneous thermal ablation plus GM

  11. What are the current indications for use of radiofrequency devices in hip arthroscopy? A systematic review

    PubMed Central

    Suarez-Ahedo, Carlos; Pavan Vemula, S.; Stake, Christine E.; Finley, Zachary A.; Martin, Timothy J.; Gui, Chengcheng; Domb, Benjamin G.

    2015-01-01

    The role of radiofrequency energy (RFE) devices has been minimally studied in hip arthroscopy. The purpose of this study was to determine the role of RFE devices in hip arthroscopy through a systematic review of the literature. We searched the PubMed database using the following Medical Subject Heading terms: hip arthroscopy, hip radiofrequency, thermal capsulorrhaphy, thermal chondroplasty and radiofrequency debridement. Two authors independently reviewed the literature and included articles based on predetermined inclusion criteria. We excluded review, technique and experimental articles. After title and abstract review, we selected 293 articles for full-text review. Ten articles met the inclusion and exclusion criteria. For the included articles, a total of 305 hips underwent arthroscopy with concomitant RFE treatment at a mean age of 25.7 years. Eight articles presented patient-reported outcome (PRO) instruments, one study did not report an outcome instrument but utilized an evaluation of postoperative range of motion (ROM) and 1 year magnetic resonance image (MRI) and computed tomography (CT) imaging. The remaining article measured only the ROM pre- and postoperatively. Only one of the articles reviewed reported complications. Current evidence on the safety and indications for use of RFE devices in hip arthroscopy is insufficient. The literature shows mixed results regarding its use in hip arthroscopy. Although the use of thermal energy is not without risk, if used judiciously and appropriate precautions are taken to avoid damage to adjacent tissues, those devices can be useful for the treatment of certain intra-articular hip pathologies arthroscopically. PMID:27011856

  12. Assessment of outdoor radiofrequency electromagnetic field exposure through hotspot localization using kriging-based sequential sampling.

    PubMed

    Aerts, Sam; Deschrijver, Dirk; Verloock, Leen; Dhaene, Tom; Martens, Luc; Joseph, Wout

    2013-10-01

    In this study, a novel methodology is proposed to create heat maps that accurately pinpoint the outdoor locations with elevated exposure to radiofrequency electromagnetic fields (RF-EMF) in an extensive urban region (or, hotspots), and that would allow local authorities and epidemiologists to efficiently assess the locations and spectral composition of these hotspots, while at the same time developing a global picture of the exposure in the area. Moreover, no prior knowledge about the presence of radiofrequency radiation sources (e.g., base station parameters) is required. After building a surrogate model from the available data using kriging, the proposed method makes use of an iterative sampling strategy that selects new measurement locations at spots which are deemed to contain the most valuable information-inside hotspots or in search of them-based on the prediction uncertainty of the model. The method was tested and validated in an urban subarea of Ghent, Belgium with a size of approximately 1 km2. In total, 600 input and 50 validation measurements were performed using a broadband probe. Five hotspots were discovered and assessed, with maximum total electric-field strengths ranging from 1.3 to 3.1 V/m, satisfying the reference levels issued by the International Commission on Non-Ionizing Radiation Protection for exposure of the general public to RF-EMF. Spectrum analyzer measurements in these hotspots revealed five radiofrequency signals with a relevant contribution to the exposure. The radiofrequency radiation emitted by 900 MHz Global System for Mobile Communications (GSM) base stations was always dominant, with contributions ranging from 45% to 100%. Finally, validation of the subsequent surrogate models shows high prediction accuracy, with the final model featuring an average relative error of less than 2dB (factor 1.26 in electric-field strength), a correlation coefficient of 0.7, and a specificity of 0.96.

  13. Sacroiliac joint pain: Prospective, randomised, experimental and comparative study of thermal radiofrequency with sacroiliac joint block.

    PubMed

    Cánovas Martínez, L; Orduña Valls, J; Paramés Mosquera, E; Lamelas Rodríguez, L; Rojas Gil, S; Domínguez García, M

    2016-05-01

    To compare the analgesic effects between the blockade and bipolar thermal radiofrequency in the treatment of sacroiliac joint pain. Prospective, randomised and experimental study conducted on 60 patients selected in the two hospitals over a period of nine months, who had intense sacroiliac joint pain (Visual Analogue Scale [VAS]>6) that lasted more than 3 months. Patients were randomised into three groups (n=20): Group A (two intra-articular sacroiliac injections of local anaesthetic/corticosteroid guided by ultrasound in 7 days). Group B: conventional bipolar radiofrequency "palisade". Target points were the lateral branch nerves of S1, S2, and S3, distance needles 1cm. Group C: modified bipolar radiofrequency "palisade" (needle distance >1cm). Patients were evaluated at one month, three months, and one year. Demographic data, VAS reduction, and side effects of the techniques were assessed. One month after the treatment, pain reduction was >50% in the three groups P<.001. Three and 12 months after the technique, the patients of the group A did not have a significant reduction in pain. At 3 months, almost 50% patients of the group B referred to improvement of the pain (P=.03), and <25% at 12 months, and those results were statistically significant (P=.01) compared to the baseline. Group C showed an improvement of 50% at 3 and 12 months (P<.001). All patients completed the study. Bipolar radiofrequency "palisade", especially when the distance between the needles was increased, was more effective and lasted longer, compared to join block and steroids, in relieving pain sacroiliac joint. Copyright © 2015 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. Clinical applications of radiofrequency: nonsurgical skin tightening (thermage).

    PubMed

    Hodgkinson, Darryl J

    2009-04-01

    Thermage is a nonsurgical treatment for sagging skin in the jowl, neck, and eyelids. Abdominal striae, loose upper arm skin and buttock sagging, and improvement of the appearance of cellulite have become amenable to the radiofrequency treatment. Radiofrequency passed through cooled epidermis allows for radiofrequency-induced thermal damage to the dermis and deep dermal collagen (fibrous septae). The remodeling of the collagen leads to clinically discernible improvement in the sagging skin and skin quality; the remodeling of deep dermal collagen (fibrous septae) allows modeling of contours and improvement of the cellulite appearance.

  15. Radiofrequency energy-induced heating of bovine articular cartilage using a bipolar radiofrequency electrode.

    PubMed

    Shellock, F G; Shields, C L

    2000-01-01

    Radiofrequency energy is used for thermal-assisted chondroplasty to treat grade II and III chondromalacia with the lowest possible energy setting that achieves the desired result. The purpose of this in vitro study was to determine the temperature changes associated with the use of radiofrequency energy delivered at different settings to bovine articular cartilage using a bipolar electrode. Cartilage samples were placed in a temperature-controlled (37 degrees C) saline bath for the delivery of radiofrequency energy. A fluoroptic thermometry probe was positioned to record the temperatures at the electrode-tissue interface. The electrode was activated for 2 seconds at settings of V2-120, V2-60, V2-40, and V2-20 in two modes: ablation and desiccation. Additionally, the cartilage samples were visually inspected to determine changes in appearance. The highest average temperatures were as follows: ablation mode, 78.5 degrees C (V2-120), 62.6 degrees C (V2-60), 58.1 degrees C (V2-40), and 54.1 degrees C (V2-20); desiccation mode, 71.8 degrees C (V2-120), 61.4 degrees C (V2-60), 57.7 degrees C (V2-40), and 53.3 degrees C (V2-20). There were statistically significant increases in temperatures associated with each of the respective settings. There were no substantial visual changes produced by the V2-20 settings, while the other settings produced a gradation of effects. These data provide information to help guide the use of a bipolar radiofrequency electrode and electrosurgical system for thermal-assisted chondroplasty.

  16. Thermal compression and molding of atherosclerotic vascular tissue with use of radiofrequency energy: implications for radiofrequency balloon angioplasty

    SciTech Connect

    Lee, B.I.; Becker, G.J.; Waller, B.F.; Barry, K.J.; Connolly, R.J.; Kaplan, J.; Shapiro, A.R.; Nardella, P.C.

    1989-04-01

    The combined delivery of pressure and thermal energy may effectively remodel intraluminal atherosclerotic plaque and fuse intimal tears. To test these hypotheses with use of a non-laser thermal energy source, radiofrequency energy was delivered to postmortem human atherosclerotic vessels from a metal hot-tip catheter, block-mounted bipolar electrodes and from a prototype radiofrequency balloon catheter. Sixty-two radiofrequency doses delivered from a metal electrode tip produced dose-dependent ablation of atherosclerotic plaque, ranging from clean and shallow craters with histologic evidence of thermal compression at doses less than 40 J to tissue charring and vaporization at higher (greater than 80 J) doses. Lesion dimensions ranged between 3.14 and 3.79 mm in diameter and 0.20 and 0.47 mm in depth. Tissue perforation was not observed. To test the potential for radiofrequency fusion of intimal tears, 5 atm of pressure and 200 J radiofrequency energy were delivered from block-mounted bipolar electrodes to 48 segments of human atherosclerotic aorta, which had been manually separated into intima-media and media-adventitial layers. Significantly stronger tissue fusion resulted (28.5 +/- 3.3 g) with radiofrequency compared with that with pressure alone (4.8 +/- 0.26 g; p less than 0.0001). A prototype radiofrequency balloon catheter was used to deliver 3 atm of balloon pressure with or without 200 J radiofrequency energy to 20 postmortem human atherosclerotic arterial segments. In 10 of 10 radiofrequency-treated vessels, thermal molding of both normal and atherosclerotic vessel wall segments resulted with increased luminal diameter and histologic evidence of medial myocyte damage.

  17. Thermal compression and molding of atherosclerotic vascular tissue with use of radiofrequency energy: implications for radiofrequency balloon angioplasty.

    PubMed

    Lee, B I; Becker, G J; Waller, B F; Barry, K J; Connolly, R J; Kaplan, J; Shapiro, A R; Nardella, P C

    1989-04-01

    The combined delivery of pressure and thermal energy may effectively remodel intraluminal atherosclerotic plaque and fuse intimal tears. To test these hypotheses with use of a non-laser thermal energy source, radiofrequency energy was delivered to postmortem human atherosclerotic vessels from a metal "hot-tip" catheter, block-mounted bipolar electrodes and from a prototype radiofrequency balloon catheter. Sixty-two radiofrequency doses delivered from a metal electrode tip produced dose-dependent ablation of atherosclerotic plaque, ranging from clean and shallow craters with histologic evidence of thermal compression at doses less than 40 J to tissue charring and vaporization at higher (greater than 80 J) doses. Lesion dimensions ranged between 3.14 and 3.79 mm in diameter and 0.20 and 0.47 mm in depth. Tissue perforation was not observed. To test the potential for radiofrequency fusion of intimal tears, 5 atm of pressure and 200 J radiofrequency energy were delivered from block-mounted bipolar electrodes to 48 segments of human atherosclerotic aorta, which had been manually separated into intima-media and media-adventitial layers. Significantly stronger tissue fusion resulted (28.5 +/- 3.3 g) with radiofrequency compared with that with pressure alone (4.8 +/- 0.26 g; p less than 0.0001). A prototype radiofrequency balloon catheter was used to deliver 3 atm of balloon pressure with or without 200 J radiofrequency energy to 20 postmortem human atherosclerotic arterial segments. In 10 of 10 radiofrequency-treated vessels, thermal "molding" of both normal and atherosclerotic vessel wall segments resulted with increased luminal diameter and histologic evidence of medial myocyte damage.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Novel use of epidural catheter: Air injection for neuroprotection during radiofrequency ablation of spinal osteoid osteoma

    PubMed Central

    Doctor, JR; Solanki, SL; Patil, VP; Divatia, JV

    2016-01-01

    Osteoid osteoma (OO) is a benign bone tumor, with a male-female ratio of approximately 2:1 and mainly affecting long bones. Ten percent of the lesions occur in the spine, mostly within the posterior elements. Treatment options for OO include surgical excision and percutaneous imaging-guided radiofrequency ablation (RFA). Lesions within the spine have an inherent risk of thermal damage to the vital structure because of proximity to the neural elements. We report a novel use of the epidural catheter for air injection for the neuroprotection of nerves close to the OO of the spine. A 12-year-old and 30 kg male child with an OO of the L3 vertebra was taken up for RFA. His preoperative examinations were within normal limits. The OO was very close to the L3 nerve root. Under general anesthesia, lumbar epidural catheter was placed in the L3-L4 space under imaging guidance. Ten ml of aliquots of air was injected under imaging guidance to avoid injury to the neural structures due to RFA. The air created a gap between neural elements and the tumor and served as an insulating material thereby protecting the neural elements from damage due to the RFA. Postoperatively, the patient did not develop any neurological deficit. PMID:27375396

  19. Osteoid osteoma - radiofrequency ablation treatment guided by computed tomography: a case series.

    PubMed

    Endo, Rosana Raquel; Gama, Natalia Fabris; Nakagawa, Suely Akiko; Tyng, Chiang Jeng; Chung, Wu Tu; Pinto, Fábio Fernando Eloi

    2017-01-01

    The osteoid osteoma is a benign primary bone tumor that affects mainly males in the second and third decades of life. Radiographic findings show a radiolucent nidus surrounded by reactive sclerotic bone, particularly in the long bones of the lower extremity. Clinically, it presents persistent pain, which is worse at night and improves with salicylates. It can be a self-limiting injury, with an average duration of three years, but because of pain intensity and intolerance to prolonged use of nonsteroidal anti-inflammatories, surgical treatment is an option. The diagnosis is suspected according to the history and radiographic findings, and the confirmation is made by histological analysis. The traditional surgical treatment is the complete excision of the nidus, but some disadvantages have been described, such as difficulties in localizing the lesion and risk of fracture during the procedure, hospital stay for pain control, and unfavorable esthetic outcome. The authors report a series of cases treated with thermal radiofrequency ablation guided by computed tomography in this service. It is a safe and an effective percutaneous method that aims to cure, minimizing the trauma and morbidity when compared with the conventional block-resection method.

  20. The fat content of small primary breast cancer interferes with radiofrequency-induced thermal ablation.

    PubMed

    Athanassiou, E; Sioutopoulou, D; Vamvakopoulos, N; Karasavvidou, F; Tzovaras, G; Tziastoudi, E; Sakellariou, M; Hatzitheofilou, C

    2009-01-01

    Radiofrequency (RF) thermal ablation is a minimally invasive technique of local mass elimination with variable efficiency. Ten patients with small primary breast cancer diagnosed preoperatively by core needle biopsy were ablated percutaneously by an RF (Radionics Cool-tip) device operating on impedance control mode. The percent fat-containing area was calculated in each slide of a total of 47 slides introduced to IQ materials software image analysis. Seven of 10 tumors with tumor diameter less than 2.8 cm and fat content less than 12.47% were totally ablated (score 3). One of 10 with 3 cm tumor diameter and 5.45% fat content showed an intermediate degree of ablated tissue (score 2), and the last 2 with 2 cm and 2.2 cm tumor diameter and more than 19.74% tumor fat content were minimally ablated (score 1). Our present exploratory study on 10 patients suggests dependence of the degree of thermal damage on tumor fat content. We conclude that the fat content of small primary breast cancer could serve as a 'heat sink' and should be considered as a preventing factor of complete local tumor destruction by RF thermal ablation. (c) 2008 S. Karger AG, Basel.

  1. CT-guided versus laparoscopic radiofrequency ablation in recurrent small hepatocellular carcinoma against the diaphragmatic dome

    PubMed Central

    Ding, Huaiyin; Su, Mu; Zhu, Chuandong; Wang, Lixue; Zheng, Qin; Wan, Yuan

    2017-01-01

    Computed tomography-guided radiofrequency ablation (CT-RFA) and laparoscopic RFA (L-RFA) have been used to treat intrahepatic recurrent small hepatocellular carcinoma (HCC) against the diaphragmatic dome. However, the therapeutic safety, efficacy, and hospital fee have never been compared between the two techniques due to scarcity of cases. In this retrospective study, 116 patients were divided into two groups with a total of 151 local recurrent HCC lesions abutting the diaphragm. We compared overall survival (OS), local tumor progression (LTP), postoperative complications, and hospital stay and fee between the two groups. Our findings revealed no significant differences in 5-year OS (36.7% vs. 44.6%, p = 0.4289) or 5-year LTP (73.3% vs. 67.9%, p = 0.8897) between CT-RFA and L-RFA. The overall hospital stay (2.8 days vs. 4.1 days, p < 0.0001) and cost (¥ 19217.6 vs. ¥ 25553.6, p < 0.0001) were significantly lower in the CT-RFA in comparison to that of L-RFA. In addition, we elaborated on the choice of percutaneous puncture paths depending on the locations of the HCC nodules and 11-year experience with CT-RFA. In conclusion, CT-RFA is a relatively easy and economic technique for recurrent small HCC abutting the diaphragm, and both CT-RFA and L-RFA are effective techniques. PMID:28291254

  2. Radiofrequency ablation versus resection for resectable colorectal liver metastases: time for a randomized trial?

    PubMed

    Mulier, Stefaan; Ni, Yicheng; Jamart, Jacques; Michel, Luc; Marchal, Guy; Ruers, Theo

    2008-01-01

    Surgical resection is the gold standard in the treatment of resectable colorectal liver metastases (CRLM). In several centers, resection is being replaced by radiofrequency ablation (RFA), even though there is no evidence yet from randomized trials to support this. The aim of this study was to critically review the oncological evidence for and against the use of RFA for resectable CRLM. An exhaustive review of RFA of colorectal metastases was carried out. Five-year survival data after RFA for resectable CRLM are not available. Percutaneous RFA is associated with worse local control, worse staging, and a small risk of electrode track seeding when compared with resection (level V evidence). For tumors

  3. Effect of heat sink on the recurrence of small malignant hepatic tumors after radiofrequency ablation.

    PubMed

    Lin, Zheng-Yu; Li, Guo-Lin; Chen, Jin; Chen, Zhong-Wu; Chen, Yi-Ping; Lin, Sun-Zhi

    2016-12-01

    The aim of this study was to investigate the effect of heat sink on the recurrence of hepatic malignant tumors <3 cm after percutaneous radiofrequency ablation (RFA). This study included 564 hepatic malignant tumors <3 cm in 381 patients. Preoperative images were used to determine whether these tumors were adjacent to vessels, and the diameter of adjacent vessels was measured. RFA was performed computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound (US) guidance, and postoperative imaging follow-up was then conducted. SPSS software version 17.0 was used for data processing, and the χ2 test was used for comparative analysis. Two-sided P < 0.05 indicated statistical significance. A total of 33 recurrences were found: 15 in the MR group (15/468), 12 in the US group (12/53), and 6 in the CT group (6/43). Of the 101 lesions adjacent to blood vessels larger than 3 mm, 20 showed recurrence: 10 in the MR group (10/77), 7 in the US group (7/17), and 3 in the CT group (3/7). The recurrence rate of perivascular lesions was higher than that of nonperivascular lesions, and the rate in the MR group was lower those in the US and CT groups. The curative effect of MRI-guided RFA is better than those of US- and CT-guided ablation. The heat sink effect is an important factor affecting recurrence of hepatic malignant tumors after RFA.

  4. Endovenous obliteration with radiofrequency-resistive heating for greater saphenous vein insufficiency: a feasibility study.

    PubMed

    Rautio, Tero T; Perälä, Jukka M; Wiik, Heikki T; Juvonen, Tatu S; Haukipuro, Kari A

    2002-06-01

    To assess the feasibility, safety, and clinical utility of ultrasound (US)- and fluoroscopy-guided endovenous saphenous vein obliteration with radiofrequency (RF)-resistive heating in the treatment of primary venous insufficiency. Thirty legs of 27 patients with mild to moderate varicose veins and primary greater saphenous vein (GSV) insufficiency diagnosed with duplex US were treated. An endovenous catheter was inserted via US-guided percutaneous puncture or a skin incision. Fluoroscopy and US were used to locate the electrodes at the saphenofemoral junction. GSVs were occluded with RF-resistive heating. Local phlebectomies or sclerotherapy were performed in all procedures to treat varicose veins and teleangiectases. Persistence of vein occlusion and complications potentially attributable to endovenous treatment were assessed at 1 week, 6 weeks, 3 months, 6 months, and 1 year. The mean follow-up time was 9.6 months (SD, 3.8 mo). By the time of the last follow-up visit, occlusion of the treated segment of the GSV had been achieved in 22 legs (73.3%). Persisting patency or recanalization of the GSV was detected in eight legs (26.7%). One patient (3.3%) had varicosity-related symptoms, and three treated legs (10%) had recurrent or new varicosities. Postoperative complications included saphenous nerve paresthesia in three legs (10%) and thermal skin injury in one limb (3.3%). Endovenous obliteration employing RF-resistive heating is a relatively safe and promising minimally invasive technique for the treatment of primary GSV insufficiency.

  5. CT-guided versus laparoscopic radiofrequency ablation in recurrent small hepatocellular carcinoma against the diaphragmatic dome.

    PubMed

    Ding, Huaiyin; Su, Mu; Zhu, Chuandong; Wang, Lixue; Zheng, Qin; Wan, Yuan

    2017-03-14

    Computed tomography-guided radiofrequency ablation (CT-RFA) and laparoscopic RFA (L-RFA) have been used to treat intrahepatic recurrent small hepatocellular carcinoma (HCC) against the diaphragmatic dome. However, the therapeutic safety, efficacy, and hospital fee have never been compared between the two techniques due to scarcity of cases. In this retrospective study, 116 patients were divided into two groups with a total of 151 local recurrent HCC lesions abutting the diaphragm. We compared overall survival (OS), local tumor progression (LTP), postoperative complications, and hospital stay and fee between the two groups. Our findings revealed no significant differences in 5-year OS (36.7% vs. 44.6%, p = 0.4289) or 5-year LTP (73.3% vs. 67.9%, p = 0.8897) between CT-RFA and L-RFA. The overall hospital stay (2.8 days vs. 4.1 days, p < 0.0001) and cost (¥ 19217.6 vs. ¥ 25553.6, p < 0.0001) were significantly lower in the CT-RFA in comparison to that of L-RFA. In addition, we elaborated on the choice of percutaneous puncture paths depending on the locations of the HCC nodules and 11-year experience with CT-RFA. In conclusion, CT-RFA is a relatively easy and economic technique for recurrent small HCC abutting the diaphragm, and both CT-RFA and L-RFA are effective techniques.

  6. Reconstruction of Vertebral Body After Radiofrequency Ablation and Augmentation in Dorsolumbar Metastatic Vertebral Fracture: Analysis of Clinical and Radiological Outcome in a Clinical Series of 18 Patients.

    PubMed

    Maugeri, Rosario; Graziano, Francesca; Basile, Luigi; Gulì, Carlo; Giugno, Antonella; Giammalva, Giuseppe Roberto; Visocchi, Massimiliano; Iacopino, Domenico Gerardo

    2017-01-01

    Painful spinal metastases usually occur in malignant neoplastic disease. Treatment for bone metastases has been largely conservative, and it includes the use of high doses of analgesics, radiotherapy, chemotherapy, hormone therapy, and bisphosphonates; however, results are sometimes transient and ineffective. In the presence of neurological involvement a surgical strategy should be considered. Recently, percutaneous procedures such as radiofrequency ablation, vertebroplasty, and kyphoplasty have been introduced as palliative techniques to treat painful vertebral metastases [3, 11, 25]. In our study we combined the use of radiofrequency ablation with vertebroplasty in the treatment of dorsolumbar metastatic vertebral fractures in order to examine the relationship between restoration of the vertebral structure and decrease in pain. From January 2014 to March 2015 we retrospectively analyzed 18 patients with malignant vertebral lesions who underwent radiofrequency ablation with vertebroplasty followed by cementoplasty, with posterior transpedicle fixation on levels near the lesions. The parameters examined were: demographics, pain relief, and the distribution of polymethylmethacrylate (PMMA) determined by the mean Saliou filling score; all complications were recorded. The mean age of the patients was 55.72 years (range 34-69); average operative time was 60.4 min (range, 51-72). The average pain index score (visual analog score; VAS) decreased significantly from 8.05 at baseline to 3.0 (p < 0.05) after 6 months. The Saliou filling score revealed a distribution of PMMA in the vertebral body that was satisfactory (12-18) in eight patients, mediocre (6-12) in seven patients, and inadequate (0-6) in the remaining three patients. In two vertebrae, minimal asymptomatic cement leakage occurred in the lateral recess without neurological damage. No pulmonary embolism and no visceral or neural damage was recorded. Radiofrequency ablation combined with vertebroplasty seems to

  7. [Percutaneous myocardial laser revascularization (PMR)].

    PubMed

    Lauer, B; Stahl, F; Bratanow, S; Schuler, G

    2000-09-01

    In patients with severe angina pectoris due to coronary artery disease, who are not candidates for either percutaneous coronary angioplasty or coronary artery bypass surgery, transmyocardial laser revascularization (TMR) often leads to improvement of clinical symptoms and increased exercise capacity. One drawback of TMR is the need for surgical thoracotomy in order to gain access to the epicardial surface of the heart. Therefore, a catheter-based system has been developed, which allows creation of laser channels into the myocardium from the left ventricular cavity. Between January 1997 and November 1999, this "percutaneous myocardial laser revascularization" (PMR) has been performed in 101 patients at the Herzzentrum Leipzig. In 63 patients, only 1 region of the heart (anterior, lateral, inferior or septal) was treated with PMR, in 38 patients 2 or 3 regions were treated in 1 session. There were 12.3 +/- 4.5 (range 4 to 22) channels/region created into the myocardium. After 3 months, the majority of patients reported significant improvement of clinical symptoms (CCS class at baseline: 3.3 +/- 0.4, after 6 months: 1.6 +/- 0.8) (p < 0.001) and an increased exercise capacity (baseline: 397 +/- 125 s, after 6 months: 540 +/- 190 s) (p < 0.05). After 2 years, the majority of patients had experienced sustained clinical benefit after PMR, the CCS class after 2 years was 1.3 +/- 0.7, exercise capacity was 500 +/- 193 s. However, thallium scintigraphy failed to show increased perfusion in the PMR treated regions. The pathophysiologic mechanisms of myocardial laser revascularization is not yet understood. Most of the laser channels are found occluded after various time intervals after intervention. Other possible mechanisms include myocardial denervation or angioneogenesis after laser revascularization, however, unequivocal evidence for these theories is not yet available. In conclusion, PMR seems to be a safe and feasible new therapeutic option for patients with refractory

  8. Aortic valve laceration following coronary angiography and percutaneous coronary intervention.

    PubMed

    Roy, James; Manganas, Con; Youssef, George; Rees, David

    2016-11-01

    Valve complications following coronary angiography and percutaneous coronary interventions are rare. We report a case of an aortic valve laceration following cardiac catheterization and percutaneous coronary intervention, which required surgical valve replacement. © 2016 Wiley Periodicals, Inc.

  9. Percutaneous nephrolithotomy: Large tube, small tube, tubeless, or totally tubeless?

    PubMed

    Agrawal, Madhu S; Agarwal, Mayank

    2013-07-01

    The role of percutaneous nephrostomy tube for drainage after percutaneous nephrolithotomy (PCNL) procedure has come under scrutiny in recent years. The procedure has been modified to use of small diameter tubes, 'tubeless' PCNL, and even 'totally tubeless' PCNL. A review of the available literature confirms that the chosen method of drainage after PCNL has a bearing upon the post-operative course. It is generally recognized now that small tubes offer benefit in terms of reduced post-operative pain and morbidity. Similarly, nephrostomy-free or 'tubeless' PCNL, using a double-J stent or ureteric catheter as alternative form of drainage, can be used with a favorable outcome in selected patients with the advantage of decreased postoperative pain, analgesia requirement, and hospital stay. Although the tubeless technique has been applied for extended indications as well, the available evidence is insufficient, and needs to be substantiated by prospective randomized trials. In addition, 'totally tubeless' approach has also been shown to be feasible in selected patients.

  10. [Percutaneous cementoplasty for malignant osteolysis of the acetabulum].

    PubMed

    Cotten, A; Duquesnoy, B

    1995-09-30

    The development of malignant lesions in the acetabulum can lead to painful and disabling bone destruction. In carefully selected patients where the cortical still provides a sufficient barrier protecting the joint, percutaneous injection of ciment (10-15 cc) can be a successful mean of countering both pain and functional impairment. This easy-to-perform technique requires only local anaesthesia and can be highly cost-effective. The antalgic effect is rapid. Most patients are able to walk again within 1 to 5 days (an effect which is particularly spectacular in bedridden subjects) probably due to the reduced pain and to better distribution of the mechanical forces. Hospitalization is usually shortened. In our experience with 18 patients, clinical improvement has been maintained for up to 18 months (mean follow-up 7 months) if the osteolytic process remains under control. Secondary effects are not rare but usually temporary. Recurrent pain, fever and/or inflammatory processes have been observed and usually resolve within 1 to 4 days. Intra-articular leakage can be avoided by careful patient selection. In association with radiotherapy, percutaneous injection of ciment appears to be an useful alternative to surgery for patients with destructive malignant lesions of the acetabulum, particularly in those with a poor clinical status and a short life expectancy. This technique has already been shown to be effective in lesions of the vertebral bodies. Several teams have made further attempts in other localizations.

  11. Radiofrequency identification for inventory in neurointerventional practice.

    PubMed

    Byers, Ernest; Gomez, Max A; Sheridan, Robert M; Orr, Nelson W; Hirsch, Joshua A

    2011-03-01

    Implementations of radiofrequency identification (RFID) systems within hospital settings are not unique or without controversy. To date, little consideration has been given to use of this technology in clinical interventional radiologic practice. The potential financial advantages coupled with benefits to quality and safety and increases in staff satisfaction are considerable. The authors outline these advantages by enabling readers to broadly consider the systemic perspective of implementing RFID technology with an associated vision toward downstream growth. Furthermore, the authors demonstrate the benefits of RFID technology integration in reducing cost and increasing quality assurance and the on-time delivery of services. Implementing RFID requires commitment from frontline technologist staff members to work collaboratively with management and external vendors. Ultimately, the authors believe this technology can positively influence patient care.

  12. Multiparametric imaging with heterogeneous radiofrequency fields

    NASA Astrophysics Data System (ADS)

    Cloos, Martijn A.; Knoll, Florian; Zhao, Tiejun; Block, Kai T.; Bruno, Mary; Wiggins, Graham C.; Sodickson, Daniel K.

    2016-08-01

    Magnetic resonance imaging (MRI) has become an unrivalled medical diagnostic technique able to map tissue anatomy and physiology non-invasively. MRI measurements are meticulously engineered to control experimental conditions across the sample. However, residual radiofrequency (RF) field inhomogeneities are often unavoidable, leading to artefacts that degrade the diagnostic and scientific value of the images. Here we show that, paradoxically, these artefacts can be eliminated by deliberately interweaving freely varying heterogeneous RF fields into a magnetic resonance fingerprinting data-acquisition process. Observations made based on simulations are experimentally confirmed at 7 Tesla (T), and the clinical implications of this new paradigm are illustrated with in vivo measurements near an orthopaedic implant at 3T. These results show that it is possible to perform quantitative multiparametric imaging with heterogeneous RF fields, and to liberate MRI from the traditional struggle for control over the RF field uniformity.

  13. Electromagnetic limits to radiofrequency (RF) neuronal telemetry.

    PubMed

    Diaz, R E; Sebastian, T

    2013-12-18

    The viability of a radiofrequency (RF) telemetry channel for reporting individual neuron activity wirelessly from an embedded antenna to an external receiver is determined. Comparing the power at the transmitting antenna required for the desired Channel Capacity, to the maximum power that this antenna can dissipate in the body without altering or damaging surrounding tissue reveals the severe penalty incurred by miniaturization of the antenna. Using both Specific Absorption Rate (SAR) and thermal damage limits as constraints, and 300 Kbps as the required capacity for telemetry streams 100 ms in duration, the model shows that conventional antennas smaller than 0.1 mm could not support human neuronal telemetry to a remote receiver (1 m away.) Reducing the antenna to 10 microns in size to enable the monitoring of single human neuron signals to a receiver at the surface of the head would require operating with a channel capacity of only 0.3 bps.

  14. Piezoelectric radiofrequency transducers as passive buried sensors

    NASA Astrophysics Data System (ADS)

    Rétornaz, T.; Friedt, J.-M.; Alzuaga, S.; Baron, T.; Lebrasseur, É.; Martin, G.; Laroche, T.; Ballandras, S.; Griselin, M.; Simonnet, J.-P.

    2012-09-01

    We demonstrate that single-piezoelectric substrate-based acoustic transducers act as ideal sensors for probing with various RADAR strategies. Because these sensors are intrinsically passive devices working in the radiofrequency range, they exhibit improved interrogation range and robustness with respect to silicon-based radio frequency identification tags. Both wideband (acoustic delay lines) and narrowband (acoustic resonators) transducers are shown to be compatible with pulse-mode and frequency-modulated continuous-wave RADAR strategies, respectively. We particularly focus on the ground-penetrating RADAR (GPR) application in which the lack of local energy source makes these sensors suitable candidates for buried applications in roads, building or civil engineering monitoring. A novel acoustic sensor concept - high-overtone bulk acoustic resonator - is especially suited as sensor interrogated by a wide range of antenna set, as demonstrated with GPR units working in the 100 and 200 MHz range.

  15. Radiofrequency Ablation Therapy for Solid Tumors

    SciTech Connect

    Kam, Anthony

    2002-12-04

    Surgical resection, systemic chemotherapy, and local radiation have been the conventional treatments for localized solid cancer. Because certain patients are not candidates for tumor resection and because many tumors are poorly responsive to chemotherapy and radiation, there has been an impetus to develop alternative therapies. Radiofrequency ablation (RFA) is a minimally invasive therapy for localized solid cancers that has gained considerable attention in the last 12 years. Advantages of minimally invasive therapies over surgery include less recovery time, lower morbidity and mortality, eligibility of more patients, and lower cost. RFA has been applied most extensively to inoperable hepatic tumors. It is investigational for tumors in the kidney, lung, bone, breast, and adrenal gland. This colloquium will review the mechanism, techniques, limitations, and clinical applications of RFA. The ultimate role that RFA will play in cancer therapy will depend on the results of long-term follow-up and prospective randomized trials.

  16. Optical generation of radio-frequency power

    SciTech Connect

    Hietala, V.M.; Vawter, G.A.; Brennan, T.M.; Hammons, B.E.; Meyer, W.J.

    1994-11-01

    An optical technique for high-power radio-frequency (RF) signal generation is described. The technique uses a unique photodetector based on a traveling-wave design driven by an appropriately modulated light source. The traveling-wave photodetector (TWPD) exhibits simultaneously a theoretical quantum efficiency approaching 100 % and a very large electrical bandwidth. Additionally, it is capable of dissipating the high-power levels required for the RF generation technique. The modulated light source is formed by either the beating together of two lasers or by the direct modulation of a light source. A system example is given which predicts RF power levels of 100`s of mW`s at millimeter wave frequencies with a theoretical ``wall-plug`` efficiency approaching 34%.

  17. Emerging indications of endoscopic radiofrequency ablation

    PubMed Central

    Becq, Aymeric; Camus, Marine; Rahmi, Gabriel; de Parades, Vincent; Marteau, Philippe

    2015-01-01

    Introduction Radiofrequency ablation (RFA) is a well-validated treatment of dysplastic Barrett's esophagus. Other indications of endoscopic RFA are under evaluation. Results Four prospective studies (total 69 patients) have shown that RFA achieved complete remission of early esophageal squamous intra-epithelial neoplasia at a rate of 80%, but with a substantial risk of stricture. In the setting of gastric antral vascular ectasia, two prospective monocenter studies, and a retrospective multicenter study, (total 51 patients), suggest that RFA is efficacious in terms of reducing transfusion dependency. In the setting of chronic hemorrhagic radiation proctopathy, a prospective monocenter study and a retrospective multicenter study (total 56 patients) suggest that RFA is an efficient treatment. A retrospective comparative study (64 patients) suggests that RFA improves stents patency in malignant biliary strictures. Conclusions Endoscopic RFA is an upcoming treatment modality in early esophageal squamous intra-epithelial neoplasia, as well as in gastric, rectal, and biliary diseases. PMID:26279839

  18. Multiparametric imaging with heterogeneous radiofrequency fields

    PubMed Central

    Cloos, Martijn A.; Knoll, Florian; Zhao, Tiejun; Block, Kai T.; Bruno, Mary; Wiggins, Graham C.; Sodickson, Daniel K.

    2016-01-01

    Magnetic resonance imaging (MRI) has become an unrivalled medical diagnostic technique able to map tissue anatomy and physiology non-invasively. MRI measurements are meticulously engineered to control experimental conditions across the sample. However, residual radiofrequency (RF) field inhomogeneities are often unavoidable, leading to artefacts that degrade the diagnostic and scientific value of the images. Here we show that, paradoxically, these artefacts can be eliminated by deliberately interweaving freely varying heterogeneous RF fields into a magnetic resonance fingerprinting data-acquisition process. Observations made based on simulations are experimentally confirmed at 7 Tesla (T), and the clinical implications of this new paradigm are illustrated with in vivo measurements near an orthopaedic implant at 3T. These results show that it is possible to perform quantitative multiparametric imaging with heterogeneous RF fields, and to liberate MRI from the traditional struggle for control over the RF field uniformity. PMID:27526996

  19. Auditory response to pulsed radiofrequency energy.

    PubMed

    Elder, J A; Chou, C K

    2003-01-01

    The human auditory response to pulses of radiofrequency (RF) energy, commonly called RF hearing, is a well established phenomenon. RF induced sounds can be characterized as low intensity sounds because, in general, a quiet environment is required for the auditory response. The sound is similar to other common sounds such as a click, buzz, hiss, knock, or chirp. Effective radiofrequencies range from 2.4 to 10000 MHz, but an individual's ability to hear RF induced sounds is dependent upon high frequency acoustic hearing in the kHz range above about 5 kHz. The site of conversion of RF energy to acoustic energy is within or peripheral to the cochlea, and once the cochlea is stimulated, the detection of RF induced sounds in humans and RF induced auditory responses in animals is similar to acoustic sound detection. The fundamental frequency of RF induced sounds is independent of the frequency of the radiowaves but dependent upon head dimensions. The auditory response has been shown to be dependent upon the energy in a single pulse and not on average power density. The weight of evidence of the results of human, animal, and modeling studies supports the thermoelastic expansion theory as the explanation for the RF hearing phenomenon. RF induced sounds involve the perception via bone conduction of thermally generated sound transients, that is, audible sounds are produced by rapid thermal expansion resulting from a calculated temperature rise of only 5 x 10(-6) degrees C in tissue at the threshold level due to absorption of the energy in the RF pulse. The hearing of RF induced sounds at exposure levels many orders of magnitude greater than the hearing threshold is considered to be a biological effect without an accompanying health effect. This conclusion is supported by a comparison of pressure induced in the body by RF pulses to pressure associated with hazardous acoustic energy and clinical ultrasound procedures.

  20. Pulsed radiofrequency for chronic inguinal neuralgia.

    PubMed

    Makharita, Mohamed Y; Amr, Yasser M

    2015-01-01

    Chronic inguinal neuralgia has been reported after inguinal herniorrhaphy, caesarean section, appendectomy, and trauma to the lower quadrant of the abdomen or inguinal region. This study was designed to evaluate the efficacy of pulsed radiofrequency in management of chronic inguinal neuralgia. Randomized, double-blind controlled trial. Hospital outpatient setting. Twenty-one patients were allocated into 2 groups. Group 1 received 2 cycles of pulsed radiofrequency (PRF) for each nerve root. In Group 2, after stimulation, we spent the same time to mimic PRF. Both groups received bupivacaine 0.25% +' 4 mg dexamethasone in 2 mL for each nerve root. Visual Analogue Scale (VAS) was assessed. Duration of the first block effective pain relief was reported. Repeated PRF blockade was allowed for any patient who reported a VAS > 30 mm in both groups during the one year follow-up period. The number and duration of blocks were reported and adverse effects were also reported. Significantly longer duration of pain relief was noticed in Group 1 (P = 0.005) after the first block, while the durations of pain relief of the second block were comparable (P = 0.59). In Group 1 the second PRF produced pain relief from the twenty-fourth week until the tenth month while in Group 2, pain relief was reported from the sixteenth week until the eighth month after the use of PRF. All patients in Group 2 received 3 blocks (the first was a sham PRF) during the one year follow-up period. Meanwhile, 2 PRF blocks were sufficient to achieve pain relief for patients in Group 1 except 4 patients who needed a third PRF block. No adverse events were reported. Small sample size. For intractable chronic inguinal pain, PRF for the dorsal root ganglion represents a promising treatment modality.

  1. Genetic effects of radiofrequency radiation (RFR).

    PubMed

    Verschaeve, L

    2005-09-01

    The possible effects of radiofrequency (RF) exposure on the genetic material of cells are considered very important since damage to the DNA of somatic cells can be linked to cancer development or cell death whereas damage to germ cells can lead to genetic damage in next and subsequent generations. This is why the scientific literature reports many investigations on the subject. According to a number of review papers, the conclusion so far is that there is little evidence that RFR is directly mutagenic and that adverse effects that were reported in some of the papers are predominantly the result of hyperthermia. Yet, some subtle indirect effects on DNA replication and/or transcription of genes under relatively restricted exposure conditions cannot be ruled out. Furthermore, the possibility of combined effects of RFR with environmental carcinogens/mutagens merits further attention. The present paper takes into account more recent investigations but the conclusion remains the same. A majority of studies report no increased (cyto)genetic damage but yet, a considerable number of investigations do. However, many studies were not sufficiently characterized, are therefore difficult to replicate and cannot be compared to others. Experimental protocols were very different from one study to another and investigations from a single laboratory were very often limited in the sample size or number of cells investigated, preventing a robust statistical analysis. Subtle, but significant differences between RFR-exposed and sham-exposed cells cannot be found in such conditions. For the above reasons, it was concluded at a workshop in Löwenstein (November 2002) that further investigations by individual laboratories most probably will not add much to the discussion of radiofrequency radiation (RFR) genotoxicity. Large, well coordinated, international collaborative studies involving participation of several experienced scientists are considered an alternative of uttermost importance

  2. Radiofrequency exposure near high-voltage lines.

    PubMed Central

    Vignati, M; Giuliani, L

    1997-01-01

    Many epidemiologic studies suggest a relationship between incidence of diseases like cancer and leukemia and exposure to 50/60 Hz magnetic fields. Some studies suggest a relationship between leukemia incidence in populations residing near high-voltage lines and the distance to these lines. Other epidemiologic studies suggest a relationship between leukemia incidence and exposure to 50/60 Hz magnetic fields (measured or estimated) and distance from the main system (220 or 120 V). The present work does not question these results but is intended to draw attention to a possible concurrent cause that might also increase the incidence of this disease; the presence on an electric grid of radiofrequency currents used for communications and remote control. These currents have been detected on high- and medium-voltage lines. In some cases they are even used on the main system for remote reading of electric meters. This implies that radiofrequency (RF) magnetic fields are present near the electric network in addition to the 50/60 Hz fields. This intensity of these RF fields is low but the intensity of currents induced in the human body by exposure to magnetic fields increases with frequency. Because scientific research has not yet clarified whether the risk is related to the value of magnetic induction or to the currents this kind of exposure produces in the human body, it is reasonable to suggest that the presence of the RF magnetic fields must be considered in the context of epidemiologic studies. Images Figure 3. Figure 4. Figure 5. PMID:9467084

  3. Transcutaneous temperature controlled radiofrequency for orgasmic dysfunction

    PubMed Central

    2016-01-01

    Background and Objectives To evaluate the safety, tolerability, and clinical efficacy of transcutaneous temperature controlled radiofrequency (TTCRF) on vulvovaginal tissue for orgasmic dysfunction. Study Design/Materials and Methods Subjects included 25 sexually active women, ages 21–65, with self‐reported difficulty in achieving orgasms during sex (anorgasmic or slow‐to‐orgasm). Each patient received three sessions at intervals of about 1 month. Treatment was performed using a slim S‐shaped probe with a stamp‐sized metal radiofrequency emitter on one surface of the tip (25 minutes total time on average). External treatments covered the labia majora and minora, lower mons pubis, perineal body, clitoral hood, and clitoris. Full length treatment of the vagina with concentration on the anterior wall was performed. Tissue temperature during therapy was elevated to and maintained between 40°C and 45°C. No anesthesia was required. After treatment, patients immediately resumed normal activities, including sex. Results Twenty‐three of 25 patients reported an average reduction in time to orgasm of 50%. Patients also noted significant vaginal tightening effects, increased vaginal moisture, and improved vulvar and clitoral sensitivity. All anorgasmic patients reported the ability to achieve orgasms. Two patients had minimal response. Conclusion TTCRF is an effective non‐hormonal, non‐surgical option for women having difficulty achieving orgasm. Treatment also has visible tightening effects on feminine tissues and appears to increase local blood flow, resulting in increased vaginal tightness and moisture. Improved appearance and friction resulted in improved confidence and reduced performance anxiety. Lasers Surg. Med. 48:641–645, 2016. © 2016 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc. PMID:27197701

  4. Genetic effects of radiofrequency radiation (RFR)

    SciTech Connect

    Verschaeve, L. . E-mail: luc.verschaeve@vito.be

    2005-09-01

    The possible effects of radiofrequency (RF) exposure on the genetic material of cells are considered very important since damage to the DNA of somatic cells can be linked to cancer development or cell death whereas damage to germ cells can lead to genetic damage in next and subsequent generations. This is why the scientific literature reports many investigations on the subject. According to a number of review papers, the conclusion so far is that there is little evidence that RFR is directly mutagenic and that adverse effects that were reported in some of the papers are predominantly the result of hyperthermia. Yet, some subtle indirect effects on DNA replication and/or transcription of genes under relatively restricted exposure conditions cannot be ruled out. Furthermore, the possibility of combined effects of RFR with environmental carcinogens/mutagens merits further attention. The present paper takes into account more recent investigations but the conclusion remains the same. A majority of studies report no increased (cyto)genetic damage but yet, a considerable number of investigations do. However, many studies were not sufficiently characterized, are therefore difficult to replicate and cannot be compared to others. Experimental protocols were very different from one study to another and investigations from a single laboratory were very often limited in the sample size or number of cells investigated, preventing a robust statistical analysis. Subtle, but significant differences between RFR-exposed and sham-exposed cells cannot be found in such conditions. For the above reasons, it was concluded at a workshop in Loewenstein (November 2002) that further investigations by individual laboratories most probably will not add much to the discussion of radiofrequency radiation (RFR) genotoxicity. Large, well coordinated, international collaborative studies involving participation of several experienced scientists are considered an alternative of uttermost importance

  5. Endovascular Radiofrequency Ablation for Varicose Veins

    PubMed Central

    2011-01-01

    Executive Summary Objective The objective of the MAS evidence review was to conduct a systematic review of the available evidence on the safety, effectiveness, durability and cost–effectiveness of endovascular radiofrequency ablation (RFA) for the treatment of primary symptomatic varicose veins. Background The Ontario Health Technology Advisory Committee (OHTAC) met on August 26th, 2010 to review the safety, effectiveness, durability, and cost-effectiveness of RFA for the treatment of primary symptomatic varicose veins based on an evidence-based review by the Medical Advisory Secretariat (MAS). Clinical Condition Varicose veins (VV) are tortuous, twisted, or elongated veins. This can be due to existing (inherited) valve dysfunction or decreased vein elasticity (primary venous reflux) or valve damage from prior thrombotic events (secondary venous reflux). The end result is pooling of blood in the veins, increased venous pressure and subsequent vein enlargement. As a result of high venous pressure, branch vessels balloon out leading to varicosities (varicose veins). Symptoms typically affect the lower extremities and include (but are not limited to): aching, swelling, throbbing, night cramps, restless legs, leg fatigue, itching and burning. Left untreated, venous reflux tends to be progressive, often leading to chronic venous insufficiency (CVI). A number of complications are associated with untreated venous reflux: including superficial thrombophlebitis as well as variceal rupture and haemorrhage. CVI often results in chronic skin changes referred to as stasis dermatitis. Stasis dermatitis is comprised of a spectrum of cutaneous abnormalities including edema, hyperpigmentation, eczema, lipodermatosclerosis and stasis ulceration. Ulceration represents the disease end point for severe CVI. CVI is associated with a reduced quality of life particularly in relation to pain, physical function and mobility. In severe cases, VV with ulcers, QOL has been rated to be as bad

  6. Radio-frequency wave enhanced runaway production rate

    SciTech Connect

    Chan, V.S.; McClain, F.W.

    1983-06-01

    Enhancement of runaway electron production (over that of an Ohmic discharge) can be achieved by the addition of radio-frequency waves. This effect is studied analytically and numerically using a two-dimensional Fokker--Planck quasilinear equation.

  7. 21 CFR 886.4100 - Radiofrequency electrosurgical cautery apparatus.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4100 Radiofrequency...-powered or battery-powered device intended for use during ocular surgery to coagulate tissue or...

  8. 21 CFR 886.4100 - Radiofrequency electrosurgical cautery apparatus.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4100 Radiofrequency...-powered or battery-powered device intended for use during ocular surgery to coagulate tissue or...

  9. 21 CFR 886.4100 - Radiofrequency electrosurgical cautery apparatus.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4100 Radiofrequency...-powered or battery-powered device intended for use during ocular surgery to coagulate tissue or...

  10. Osler's nodes, pseudoaneurysm formation, and sepsis complicating percutaneous radial artery cannulation.

    PubMed

    Cohen, A; Reyes, R; Kirk, M; Fulks, R M

    1984-12-01

    Percutaneous arterial cannulation is useful for hemodynamic monitoring and frequent arterial blood gas determinations in selected intensive care patients. However, this procedure is not without risk. We report a case of localized Osler node formation, distal to a radial artery catheter, associated with sepsis, pseudoaneurysm formation, and thrombosis at the site of catheterization. Complications of this technique require aggressive medical and, in selected cases, surgical intervention.

  11. Percutaneous venovenous bypass in orthotopic liver transplantation.

    PubMed

    Washburn, W K; Lewis, W D; Jenkins, R L

    1995-11-01

    Since January 1994, we have used percutaneous placement of both the subclavian and femoral cannulae to establish access for venovenous bypass during orthotopic liver transplantation. Percutaneous subclavian and femoral cannulae were used in 36 patients of which 5 had portal decompression by placement of a cannula in inferior mesenteric vein percutaneously through the abdominal wall. Intraoperative placement of the subclavian cannula is facilitated by placing a subclavian central venous line before the abdominal incision. One patient underwent exploration for femoral vein bleeding early in our experience. Another patient sustained hypotension as a result of a kinked subclavian cannula. In 4 patients, early in this experience, we had difficulty placing the subclavian cannula and resorted to axillary vein cut-down. There were no episodes of deep venous thrombosis detected by routine postoperative duplex ultrasonography. Minimum and maximum flow rates were significantly better (P < .01), with percutaneously placed cannulae in comparison to a control group of patients who underwent transplantation in whom we used the standard venous cut-down approach with a #7 Gott shunt (2.14 and 3.17 L/min v 1.65 and 2.41 L/min, respectively). Percutaneous placement of cannulae for venovenous bypass during liver transplantation is quick, safe, and effective. We would advocate this technique as an alternative approach for patients in whom bypass is deemed necessary.

  12. Radiofrequency plasma antenna generated by femtosecond laser filaments in air

    SciTech Connect

    Brelet, Y.; Houard, A.; Point, G.; Prade, B.; Carbonnel, J.; Andre, Y.-B.; Mysyrowicz, A.; Arantchouk, L.; Pellet, M.

    2012-12-24

    We demonstrate tunable radiofrequency emission from a meter-long linear plasma column produced in air at atmospheric pressure. A short-lived plasma column is initially produced by femtosecond filamentation and subsequently converted into a long-lived discharge column by application of an external high voltage field. Radiofrequency excitation is fed to the plasma by induction and detected remotely as electromagnetic radiation by a classical antenna.

  13. Percutaneous tracheostomy: comparison of Ciaglia and Griggs techniques.

    PubMed

    Añón, J M; Gómez, V; Escuela, M P; De Paz, V; Solana, L F; De La Casa, R M; Pérez, J C; Zeballos, E; Navarro, L

    2000-01-01

    Although the standard tracheostomy described in 1909 by Jackson has been extensively used in critical patients, a more simple procedure that can be performed at the bedside is needed. Since 1957 several different types of percutaneous tracheostomy technique have been described. The purpose of the present study was to compare two bedside percutaneous tracheostomy techniques: percutaneous dilatational tracheostomy (PDT) and the guidewire dilating forceps (GWDF). A prospective study in two medical/surgical intensive care units (ICUs) was carried out. Sixty-three critically ill patients who required endotracheal intubation for longer than 15 days were consecutively selected to undergo PDT (25 patients) or GWDF (38 patients) technique. Intraoperative and postoperative complications were recorded. Age (mean +/- standard error) was 63 +/- 1.1 years. The patients had been mechanically ventilated for an average of 19.8 +/- 1.2 days. The GWDF technique was significantly faster than PDT technique (P = 0.02). Fifteen complications occurred in 10 out of 63 (15%) patients. They were as follows: tracheal tear (one patient in each group; in one case this was due to false passage); transient hypotension (one patient in the PDT group and two patients in the GWDF group); atelectasis (one patient in the PDT group); and haemorrhage (one patient in the PDT group and three patients in the GWDF group). In both patients with tracheal tear, reduced arterial oxygen saturation (SaO2) with concomitant subcutaneous emphysema ensued. We found no statistical differences between complications with both techniques. The surgical time required for the GWDF technique was less than that for PDT.

  14. Percutaneous tracheostomy: comparison of Ciaglia and Griggs techniques

    PubMed Central

    Añón, José M; Gómez, Vicente; Escuela, Mª Paz; De Paz, Vicente; Solana, Luis F; De La Casa, Rosa M; Pérez, Juan C; Zeballos , Eugenio; Navarro, Luis

    2000-01-01

    Background: Although the standard tracheostomy described in 1909 by Jackson has been extensively used in critical patients, a more simple procedure that can be performed at the bedside is needed. Since 1957 several different types of percutaneous tracheostomy technique have been described. The purpose of the present study was to compare two bedside percutaneous tracheostomy techniques: percutaneous dilatational tracheostomy (PDT) and the guidewire dilating forceps (GWDF). Materials and methods: A prospective study in two medical/surgical intensive care units (ICUs) was carried out. Sixty-three critically ill patients who required endotracheal intubation for longer than 15 days were consecutively selected to undergo PDT (25 patients) or GWDF (38 patients) technique. Intraoperative and postoperative complications were recorded. Results: Age (mean ± standard error) was 63 ± 1.1 years. The patients had been mechanically ventilated for an average of 19.8 ± 1.2 days. The GWDF technique was significantly faster than PDT techni