Science.gov

Sample records for percutaneous selective radiofrequency

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. [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.

  1. 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.

  2. 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.

  3. 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

  4. 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

  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. 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

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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

  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.

  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 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.

  2. 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

  3. 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.

  4. Percutaneous ethanol injection therapy is comparable to radiofrequency ablation in hepatocellular carcinoma smaller than 1.5 cm

    PubMed Central

    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

    2016-01-01

    Abstract 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. PMID:27583865

  5. [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.

  6. 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.

  7. Treatment of liver cancer of middle and advanced stages using ultrasound-guided percutaneous ethanol injection combined with radiofrequency ablation: A clinical analysis

    PubMed Central

    SUN, XUE; LI, RU; ZHANG, BOTAO; YANG, YUEJIE; CUI, ZHIFEI

    2016-01-01

    Liver cancer is a malignancy of the digestive system and has a high morbidity and mortality rate. Local intervention has become a viable option in identifying liver treatment. The aim of the present study was to analyze the clinical effects of treating liver cancer in middle and advanced stages using ultrasound-guided percutaneous ethanol injection (PEI) in tumors combined with radiofrequency ablation (RFA). A total of 100 patients with stage III–IV liver cancers were selected to participate in the study. Patients were divided into groups. In group A, treatment was initiated with PEI and after 1–2 weeks RFA was applied while in group B treatment was initiated with RFA and after 1–2 weeks PEI was applied. Patients in group C received PEI and RFA simultaneously. The clinical effects in the 3 groups were compared after 6-month follow ups. The volume of tumor ablation necrosis in group A was significantly greater than that in the groups B and C, while the size was significantly smaller compared to groups B and C after ablation. For group A, the complete ablation rate was significantly higher than that in groups B and C, and the differences were statistically significant (P<0.05). Liver damage indices, including raising levels of glutamic-pyruvic transaminase and total bilirubin, were significantly decreased in group A (P<0.05). The survival rate in group A was also significantly higher than in groups B and C (P<0.05). In conclusion, for patients with liver cancer in middle and advanced stages, the treatment method using PEI followed by RFA was more beneficial in terms of improving the tumor ablation rate, alleviating liver damages and increasing survival rates. PMID:26998128

  8. 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

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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 ...

  11. 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

  12. 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.

  13. [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.

  14. 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.

  15. 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.

  16. 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

  17. Percutaneous ablation of adrenal tumors.

    PubMed

    Venkatesan, Aradhana M; Locklin, Julia; Dupuy, Damian E; Wood, Bradford J

    2010-06-01

    Adrenal tumors comprise a broad spectrum of benign and malignant neoplasms and include functional adrenal adenomas, pheochromocytomas, primary adrenocortical carcinoma, and adrenal metastases. Percutaneous ablative approaches that have been described and used in the treatment of adrenal tumors include percutaneous radiofrequency ablation, cryoablation, microwave ablation, and chemical ablation. Local tumor ablation in the adrenal gland presents unique challenges, secondary to the adrenal gland's unique anatomic and physiological features. The results of clinical series employing percutaneous ablative techniques in the treatment of adrenal tumors are reviewed in this article. Clinical and technical considerations unique to ablation in the adrenal gland are presented, including approaches commonly used in our practices, and risks and potential complications are discussed.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. Radiofrequency Ablation of Liver Tumors

    MedlinePlus

    ... Site Index A-Z Radiofrequency Ablation (RFA) of Liver Tumors Radiofrequency ablation (RFA) is a treatment that ... of Liver Tumors? What is Radiofrequency Ablation of Liver Tumors? Radiofrequency ablation, sometimes referred to as RFA, ...

  4. Percutaneous ablation of hepatocellular carcinoma: current status.

    PubMed

    McWilliams, Justin P; Yamamoto, Shota; Raman, Steven S; Loh, Christopher T; Lee, Edward W; Liu, David M; Kee, Stephen T

    2010-08-01

    Hepatocellular carcinoma (HCC) is an increasingly common disease with dismal long-term survival. Percutaneous ablation has gained popularity as a minimally invasive, potentially curative therapy for HCC in nonoperative candidates. The seminal technique of percutaneous ethanol injection has been largely supplanted by newer modalities, including radiofrequency ablation, microwave ablation, cryoablation, and high-intensity focused ultrasound ablation. A review of these modalities, including technical success, survival rates, and complications, will be presented, as well as considerations for treatment planning and follow-up.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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

  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.

  17. 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

  18. Percutaneous ablation of pancreatic cancer.

    PubMed

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

    2016-11-28

    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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. Pleural tumor seeding following percutaneous cryoablation of hepatocellular carcinoma.

    PubMed

    Conners, Douglas; Rilling, William

    2011-06-01

    Numerous modalities for hepatic tumor ablation are currently used including ethanol injection, radiofrequency ablation (RFA), cryoablation, and microwave ablation. The results and complications of these various tumor ablation techniques have been reported extensively, with the most data existing for percutaneous RFA. One of the most serious complications from tumor ablation is the seeding of cancer cells along the ablation tract. The incidence and risk factors for tract seeding in RFA have been reported, but little information regarding this complication with other ablation modalities has been reported. We report a case of tumor seeding into the pleural space following percutaneous cryoablation of hepatocellular carcinoma (HCC).

  5. Percutaneous thermal ablation of primary lung cancer.

    PubMed

    de Baere, T; Tselikas, L; Catena, V; Buy, X; Deschamps, F; Palussière, J

    2016-10-01

    Percutaneous ablation of small-size non-small-cell lung cancer (NSCLC) has demonstrated feasibility and safety in nonsurgical candidates. Radiofrequency ablation (RFA), the most commonly used technique, has an 80-90% reported rate of complete ablation, with the best results obtained in tumors less than 2-3cm in diameter. The highest one-, three-, and five-year overall survival rates reported in NSCLC following RFA are 97.7%, 72.9%, and 55.7% respectively. Tumor size, tumor stage, and underlying comorbidities are the main predictors of survival. Other ablation techniques such as microwave or cryoablation may help overcome the limitations of RFA in the future, particularly for large tumors or those close to large vessels. Stereotactic ablative radiotherapy (SABR) has its own complications and carries the risk of fiducial placement requiring multiple lung punctures. SABR has also demonstrated significant efficacy in treating small-size lung tumors and should be compared to percutaneous ablation.

  6. Percutaneous ablation of malignant thoracic tumors.

    PubMed

    Ghaye, B

    2013-01-01

    Lung cancer is the leading cause of death related to cancer. Fifteen to thirty percent of patients with a localized lung cancer are actually inoperable as they present with poor general condition, limited cardiopulmonary function, or a too high surgical risk. Therefore, minimally invasive treatments are needed and percutaneous ablation seems an attractive option. Thermal ablation can be performed by delivering heat (radiofrequency, microwave, laser) or cold (cryotherapy) through a needle inserted into the tumor under CT guidance. The ideal lesion is less than 2 or 3 cm in diameter. Success of percutaneous thermal ablation appears to be close to those of surgery for localized lung cancer. Nevertheless studies are still needed to definitely assess the role of ablation compared to other emerging techniques, as stereotactic radiotherapy as well as potential synergy with other treatments.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. [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.

  8. 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.

  9. Radiofrequency attenuator and method

    DOEpatents

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

    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.

  10. Percutaneous minimally invasive therapies in the treatment of bone tumors: thermal ablation.

    PubMed

    Simon, Caroline J; Dupuy, Damian E

    2006-06-01

    Many percutaneous image-guided ablative techniques have been utilized in the treatment of bone cancers. These techniques are fast becoming a focus in the treatment of patients with both benign and malignant forms of bone cancer. This article will review the principles of radiofrequency ablation including its use in combination with other therapies, cryoablation, and microwave ablation in the treatment of osteoid osteomas and bone metastases.

  11. 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

  12. 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.

  13. 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.

  14. 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 ...

  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. 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.

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. [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.

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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

  8. Current readings: Percutaneous ablation for pulmonary metastatic disease.

    PubMed

    Quirk, Matthew T; Pomykala, Kelsey L; Suh, Robert D

    2014-01-01

    Percutaneous image-guided ablation is a technique for maintaining local control of metastatic lung lesions that may, in selected patients, confer a survival benefit over no treatment or systemic therapy alone. Although the currently accepted treatment for oligometastatic pulmonary disease is surgical resection, the existing body of literature, including the recent investigations reviewed within this article, supports a role for percutaneous ablation as an important and relatively safe therapeutic option for nonsurgical and in carefully selected surgical patients, conferring survival benefits competitive with surgical metastasectomy. Continued clinical investigations are needed to further understand the nuances of thermal technologies and applications to treat lung primary and secondary pulmonary malignancy, directly compare available therapeutic options and further define the role of percutaneous image-guided ablation in the treatment of pulmonary metastatic disease.

  9. [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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. 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 ...

  16. Percutaneously inserted central catheter - infants

    MedlinePlus

    PICC - infants; PQC - infants; Pic line - infants; Per-Q cath - infants ... A percutaneously inserted central catheter (PICC) is a long, very thin, soft plastic tube that is put into a small blood vessel. This article addresses PICCs in ...

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. Radiofrequency ablation-combined multimodel therapies for hepatocellular carcinoma: Current status

    PubMed Central

    Chen, Luming; Sun, Jihong; Yang, Xiaoming

    2015-01-01

    Radiofrequency ablation (RFA) is widely accepted as a first-line interventional oncology approach for hepatocellular carcinoma (HCC) and has the advantages of high treatment efficacy and low complication risk. Local control rates equivalent to hepatic resection can be reached by RFA alone when treating small HCCs (<2 cm) in favorable locations. However, local tumor progression and recurrence rates with RFA monotherapy increase sharply when treating larger lesions (>3 cm). To address this clinical problem, recent efforts have focused on multimodel management of HCC by combining RFA with different techniques, including percutaneous ethanol injection, transarterial chemo-embolization, targeted molecular therapy, nanoparticle-mediated therapy, and immunotherapy. The combination strategy indeed leads to better outcomes in comparison to RFA alone. In this article, we review the current status of RFA-combined multimodal therapies in the management of HCC. PMID:26472630

  16. 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.

  17. 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

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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.

  4. 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

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. Percutaneous urinary procedures

    MedlinePlus

    ... Lingeman JE. Surgical management of upper urinary tract calculi. In: Wein AJ, Kavoussi LR, Novick AC, et ... CC, Nakada SY. Treatment selection and outcomes: renal calculi. Urol Clin North Am . 2007;34(3):409- ...

  12. 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.

  13. 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.

  14. 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.

  15. 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

  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. 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.

  18. 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.

  19. 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.

  20. 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

  1. Percutaneous tumor ablation tools: microwave, radiofrequency, or cryoablation--what should you use and why?

    PubMed

    Hinshaw, J Louis; 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.

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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%.

  13. 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.

  14. 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

  15. 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

  16. Comparison of percutaneous ablation technologies in the treatment of malignant liver tumors.

    PubMed

    Yu, Hyeon; Burke, Charles T

    2014-06-01

    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.

  17. [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.

  18. 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

  19. Cryoablation and radiofrequency for kidney tumor.

    PubMed

    Lehman, Daniel S; Landman, Jaime

    2008-03-01

    The detection of incidental and asymptomatic renal cortical neoplasms has concomitantly increased with radiographic imaging use. The gold standard for treating small renal tumors includes open and laparoscopic partial nephrectomy. Ablative renal procedures intend to duplicate the excellent oncologic outcomes of partial nephrectomy, while decreasing complications and shortening hospitalization time and convalescence. Only short and medium-term data are available, but ablation with cryotherapy or radiofrequency probes may achieve these goals. Ablation also offers the advantages of a minimally invasive surgical approach, with a significantly lower complication rate than partial nephrectomy. Ablated lesions are typically left in situ. Leaving potentially malignant tissues in place, albeit in a nonviable condition, certainly represents a major change in surgical thinking processes. This article reviews the status of cryoablation and radiofrequency ablation, the two ablative modalities currently available for clinical application.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. Percutaneous umbilical cord blood sampling - slideshow

    MedlinePlus

    ... htm Percutaneous umbilical cord blood sampling - series—Normal anatomy To use the sharing features on this page, ... Bethesda, MD 20894 U.S. Department of Health and Human Services National Institutes of Health Page last updated: ...

  10. 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

  11. 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.

  12. Hemodynamic support with percutaneous devices in patients with heart failure.

    PubMed

    Kapur, Navin K; Esposito, Michele

    2015-04-01

    The use of surgically implanted durable mechanical circulatory support (MCS) in high-risk patients with heart failure is declining and short-term, nondurable MCS device use is growing. Percutaneously delivered MCS options for advanced heart failure include the intra-aortic balloon pump, Impella axial flow catheter, TandemHeart centrifugal pump, and venoarterial extracorporeal membrane oxygenation. Nondurable MCS devices have unique implantation characteristics and hemodynamic effects. Algorithms and guidelines for optimal nondurable MCS device selection do not exist. Emerging technologies and applications will address the need for improved left ventricular unloading using lower-profile devices, longer-term ambulatory support, and the potential for myocardial recovery.

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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.

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. 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)

  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. [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

  18. [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.

  19. 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.

  20. 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.

  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. 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.

  3. Therapeutic impact of CT-guided percutaneous catheter drainage in treatment of deep tissue abscesses.

    PubMed

    Asai, Nobuhiro; Ohkuni, Yoshihiro; Yamazaki, Ikuo; Kaneko, Norihiro; Aoshima, Masahiro; Kawamura, Yasutaka

    2013-01-01

    Combination therapy of CT-guided percutaneous drainage and antibiotics is the first-line treatment for abscesses. Its effectiveness has been demonstrated. However, the therapeutic impact of this procedure for infection treatment has never been reported. We retrospectively analyzed all 47 patients who received CT-guided percutaneous drainage for infection treatment. Patients' characteristics, pathogens isolated, antibiotics administered, technical and clinical outcomes, complications related to this procedure and therapeutic impacts were investigated. Patients were 26 males and 21 females. The mean age was 63.5 years (±18.7). The diseases targeted were 19 retroperitoneal abscesses, 18 intra-abdominal abscesses, three pelvic abscesses, and seven others. As for technical outcomes, all of the 54 procedures (100%) were successful. As for clinical outcomes, 44 (93.6%) were cured and three patients (6.4%) died. No complications related to this procedure were found in this study. A total of 42 patients (88%) had a change in the management of their infection as a result of CT-guided percutaneous drainage, such as selection and discontinuation of antibiotics. In conclusion, CT-guided percutaneous drainage is a safe and favorable procedure in the treatment of deep tissue abscesses. Therapeutic impact of these procedures helped physicians make a rational decision for antibiotics selection.

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. [Percutaneous surgery in renal lithiasis. Current indications].

    PubMed

    Escovar Díaz, P; Rey, M; López, J R; Rodríguez, M; González, R D; la Riva, F; Turinese, L; López, J

    1991-06-01

    The indiscriminate use of extracorporeal shock waves in the treatment of urinary calculi has changed the place of percutaneous surgery in the treatment of renal lithiasis. The authors analyse current indications of PCN highlighting stone size. In their view, calculi greater than 2 cm warrant treatment by PCN since only 15-20% of patients are completely stone-free following a single session of ESWL. Attention is focussed on the staghorn calculus and the percutaneous approach. They describe the difficulty encountered in the fragmentation of the cystine calculus owing to its hardness and discuss the difficulties that may arise when using the percutaneous approach in patients with coexisting renoureteral conditions, in the treatment of lithiasis in children and in the obese patients.

  11. 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.

  12. 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.

  13. 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.

  14. Percutaneous absorption with emphasis on sunscreens.

    PubMed

    Gonzalez, Helena

    2010-04-01

    Sunscreens are widely used products. When recreationally used they are applied to large areas of the skin repeatedly. In moisturizers and foundation it is common to find sun protective ingredients, in these cases the product is usually applied to smaller areas but often done daily. Active ingredients in sunscreens can be absorbed by the skin. Percutaneous absorption is an important factor to take into consideration. There are several methods to measure the percutaneous absorption, both in vivo and/or in vitro. This paper will give an overview of the different methods.

  15. Percutaneous Nephrostomy: Technical Aspects and Indications

    PubMed Central

    Dagli, Mandeep; Ramchandani, Parvati

    2011-01-01

    First described in 1955 by Goodwin et al as a minimally invasive treatment for urinary obstruction causing marked hydronephrosis, percutaneous nephrostomy (PCN) placement quickly found use in a wide variety of clinical indications in both dilated and nondilated systems. Although the advancement of modern endourological techniques has led to a decline in the indications for primary nephrostomy placement, PCNs still play an important role in the treatment of multiple urologic conditions. In this article, the indications, placement, and postprocedure management of percutaneous nephrostomy drainage are described. PMID:23204641

  16. [Algorithm for percutaneous origin of irreversible icterus ].

    PubMed

    Marković, Z; Milićević, M; Masulović, D; Saranović, Dj; Stojanović, V; Marković, B; Kovacević, S

    2007-01-01

    It is retrospective analysis of all percutaneous billiary dranage typs used in 600 patients with opstructive icterus in last 10 years.The procedure technics is analysed. It had positiv therapeutical result in about 75% cases. The most frequent complication are showed. The most coressponding percutaneous derivation algorithm is discussed. As initial method is suggested the usage of externo-internal derivation which, in dependence of the procedure, continue by internal derivation-catheteral endoprosthesys or matelic stent. The covered metalic stents usage is suggested as method of choise in metalic endoprosthesys application.

  17. Percutaneous Cryotherapy of Vascular Malformation: Initial Experience

    SciTech Connect

    Cornelis, F.; Neuville, A.; Labreze, C.; Kind, M.; Bui, B.; Midy, D.; Palussiere, J.; Grenier, N.

    2013-06-15

    The present report describes a case of percutaneous cryotherapy in a 36-year-old woman with a large and painful pectoral venous malformation. Cryoablation was performed in a single session for this 9-cm mass with 24 h hospitalisation. At 2- and 6-month follow-up, the pain had completely disappeared, and magnetic resonance imaging demonstrated a significant decrease in size. Percutaneous cryoablation shows promise as a feasible and apparently safe method for local control in patients with symptomatic venous vascular malformations.

  18. 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

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. Multiparametric imaging with heterogeneous radiofrequency fields.

    PubMed

    Cloos, Martijn A; Knoll, Florian; Zhao, Tiejun; Block, Kai T; Bruno, Mary; Wiggins, Graham C; Sodickson, Daniel K

    2016-08-16

    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.

  6. 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

  7. 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.

  8. 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

  9. 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

  10. 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

  11. 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

  12. Complications of Minimally Invasive Percutaneous Plating for Distal Tibial Fractures

    PubMed Central

    Muzaffar, Nasir; Bhat, Rafiq; Yasin, Mohammad

    2016-01-01

    Background The management of distal tibia fractures continues to remain a source of controversy and debate. Objectives The aim of this study was to evaluate the various complications of minimally invasive percutaneous plate osteosynthesis (MIPPO) using a locking plate for closed fractures of distal tibia in a retrospective study. Patients and Methods Twenty-five patients with distal tibial fractures, treated by minimally invasive percutaneous plate osteosynthesis, were evaluated in a retrospective study. We studied the rate, probable etiological factors and preventive and corrective measures of various complications associated with minimally invasive plating of distal tibia. Results Mean age of the patients was 41.16 years (range 22 - 65). There were 13 male and 12 female patients. All fractures united at an average duration of 16.8 weeks. There were two cases of superficial and two cases of deep infection, and deep infections required removal of hardware for cure. There were four cases of ankle stiffness, most of them occurring in intra-articular fractures, three cases of palpable implant, three cases of malunion, one case of loss of reduction and one patient required reoperation. The average AO foot and ankle score was 83.6. Conclusions We found MIPPO using locking plate to be a safe and effective method for the treatment of distal tibial fractures in properly selected patients yet can result in a variety of complications if proper precautions before, during and after surgery are not taken care of. PMID:28182170

  13. 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.

  14. Percutaneous Cyanoacrylate Glue Injection into the Renal Pseudoaneurysm to Control Intractable Hematuria After Percutaneous Nephrolithotomy

    SciTech Connect

    Lal, Anupam Kumar, Ajay; Prakash, Mahesh; Singhal, Manphool; Agarwal, Mayank Mohan; Sarkar, Debansu; Khandelwal, Niranjan

    2009-07-15

    We report a case of a 43-year-old man who developed intractable hematuria after percutaneous nephrolithotomy. Angiography detected a pseudoaneurysm arising from the lower polar artery; however, embolization could not be performed because of unfavorable vascular anatomy. A percutaneous thrombin injection under ultrasound guidance initially controlled the bleeding, but hematuria subsequently recurred as a result of recanalization of the aneurysm. The case was successfully managed with ultrasound- and fluoroscopic-guided direct injection of cyanoacrylate glue into the pseudoaneurysm.

  15. Percutaneous cyanoacrylate glue injection into the renal pseudoaneurysm to control intractable hematuria after percutaneous nephrolithotomy.

    PubMed

    Lal, Anupam; Kumar, Ajay; Prakash, Mahesh; Singhal, Manphool; Agarwal, Mayank Mohan; Sarkar, Debansu; Khandelwal, Niranjan

    2009-07-01

    We report a case of a 43-year-old man who developed intractable hematuria after percutaneous nephrolithotomy. Angiography detected a pseudoaneurysm arising from the lower polar artery; however, embolization could not be performed because of unfavorable vascular anatomy. A percutaneous thrombin injection under ultrasound guidance initially controlled the bleeding, but hematuria subsequently recurred as a result of recanalization of the aneurysm. The case was successfully managed with ultrasound- and fluoroscopic-guided direct injection of cyanoacrylate glue into the pseudoaneurysm.

  16. 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.

  17. Treatment of Uterine Myomas by Radiofrequency Thermal Ablation

    PubMed Central

    Chen, Ming; Yang, Shujun; Li, Juan; Zhu, Tongyu; Zhao, Xiaoli

    2015-01-01

    Patients’ selection criteria, effectiveness, and safety of radiofrequency thermal ablation (RFTA) therapy for uterine myomas (UM) were assessed using a 10-year retrospective cohort study. From July 2001 to July 2011, a total of 1216 patients treated for UM were divided into 2 groups. Group A consisted of 476 premenopause patients, average age 36.5 ± 8.5 years, average number of myomas 1.7 ± 0.9, and average diameter of myomas 4.5 ± 1.5 cm, and group B consisted of 740 menopause patients, average age 48.5 ± 3.5 years, average number of myomas 2.6 ± 1.3, and average diameter of myomas 5.0 ± 2.5 cm. Average follow-up period was 36.5 ± 11.5 months. At 1, 3, 6, 12, and 24 months after RFTA, average diameters of myomas in group A were 3.8, 3.0, 2.7, 2.4, and 2.2 cm, respectively, and 47.7% (227 of 476) of patients had tumor trace at 12 months after RFTA. In group B, the results were 4.7, 3.7, 3.3, 2.3, and 2.3 cm, respectively, and 58.8% (435 of 740) of patients had tumor trace at 12 months after RFTA. Three months after treatment, myoma volumes were significantly reduced in both the groups (P < .01), and group B had higher rate of tumor trace at 12 months after RFTA than group A (P < .05). Clinical symptoms and health-related quality-of-life outcome (HRQL) were significantly improved after RFTA in both groups and the postoperative recurrence rate of UM was significantly higher in group A at 10.7% (51 of 476) than group B at 2.4% (18 of 740; P < .05). Radiofrequency thermal ablation is an excellent minimally invasive treatment for UM smaller than 5.0 cm in diameter. PMID:25355802

  18. Percutaneous needle biopsy for indeterminate renal masses: a national survey of UK consultant urologists

    PubMed Central

    Khan, Azhar A; Shergill, Iqbal S; Quereshi, Sheila; Arya, Manit; Vandal, Mohammed T; Gujral, Sandeep S

    2007-01-01

    Background The use of percutaneous needle biopsy in the evaluation of indeterminate renal masses is controversial and its role in management remains largely unclear. We set to establish current practice on this issue in UK urology departments. Methods We conducted a national questionnaire survey of all consultant urologists in the UK, to establish current practice and attitudes towards percutaneous needle biopsy in the management of indeterminate renal masses. Results 139 (43%) consultant urologists never use biopsy, whereas 111 (34%) always employ it for the diagnosis of indeterminate renal masses. 75 (23%) urologists use biopsy only for a selected patient group. Mass in a solitary kidney, bilateral renal masses and a past history of non-renal cancer were the main indications for use of percutaneous biopsy. The risk of false negative results and biopsy not changing the eventual management of their patients were the commonest reasons not to perform biopsy. Conclusion There is a wide and varied practice amongst UK Consultant Urologists in the use of percutaneous biopsy as part of the management of indeterminate renal masses. The majority of urologists believe biopsy confers no benefit. However there is a need to clarify this issue in the wake of recent published evidence as biopsy results may provide critical information for patients with renal masses in a significant majority. It not only differentiates benign from malignant tissue but can also help in deciding the management option for patients undergoing minimally invasive treatments. PMID:17610739

  19. Disinfection of dairy and animal farm wastewater with radiofrequency power.

    PubMed

    Lagunas-Solar, M C; Cullor, J S; Zeng, N X; Truong, T D; Essert, T K; Smith, W L; Piña, C

    2005-11-01

    Radiofrequency (RF) power was investigated as a new, physical (nonchemical), thermal process to disinfect wastewater from dairy and animal facilities. Samples (n = 38) from 8 dairy, 2 calf, and 3 swine facilities in California were collected over a 3-yr period and characterized for their dielectric properties, chemical composition, and suitability for thermal processing using RF power. To establish efficacy for disinfection, selected samples were inoculated with high levels (10(6) to 10(9) cfu/mL) of bacterial pathogens such as Salmonella sp., Escherichia coli O157:H7, and Mycobacterium avium ssp. paratuberculosis and processed with an RF prototype system. The capabilities of RF power as a method for thermal disinfection of wastewater were demonstrated when bacteria pathogens were completely and rapidly (<1 min) inactivated when temperatures of 60 to 65 degrees C were achieved. Furthermore, RF technology can be used for large-scale, batch or continuous and portable applications, allowing significant improvements in energy-use efficiencies compared with conventional thermal (surface heating) technologies. Therefore, RF power has potential as an alternative to disinfect dairy/animal farm wastewater before recycling.

  20. Simulation studies promote technological development of radiofrequency phased array hyperthermia.

    PubMed

    Wust, P; Seebass, M; Nadobny, J; Deuflhard, P; Mönich, G; Felix, R

    1996-01-01

    A treatment planning program package for radiofrequency hyperthermia has been developed. It consists of software modules for processing three-dimensional computerized tomography (CT) data sets, manual segmentation, generation of tetrahedral grids, numerical calculation and optimisation of three-dimensional E field distributions using a volume surface integral equation algorithm as well as temperature distributions using an adaptive multilevel finite-elements code, and graphical tools for simultaneous representation of CT data and simulation results. Heat treatments are limited by hot spots in healthy tissues caused by E field maxima at electrical interfaces (bone/muscle). In order to reduce or avoid hot spots suitable objective functions are derived from power deposition patterns and temperature distributions, and are utilised to optimise antenna parameters (phases, amplitudes). The simulation and optimisation tools have been applied to estimate the improvements that could be reached by upgrades of the clinically used SIGMA-60 applicator (consisting of a single ring of four antenna pairs). The investigated upgrades are increased number of antennas and channels (triple-ring of 3 x 8 antennas and variation of antenna inclination. Significant improvement of index temperatures (1-2 degrees C) is achieved by upgrading the single ring to a triple ring with free phase selection for every antenna or antenna pair. Antenna amplitudes and inclinations proved as less important parameters.

  1. Radiofrequency Neurotomy of Cervical Medial Branches for Chronic Cervicobrachialgia

    PubMed Central

    Shin, Woo-Ram; Shin, Dong-Gyu; Shin, Dong-Ah

    2006-01-01

    Chronic neck and arm pain or cervicobrachialgia commonly occurs with the degeneration of cervical spine. Authors investigated the usefulness of radiofrequency (RF) neurotomies of cervical medial branches in patients with cervicobrachialgia and analyzed the factors which can influence the treatment outcome. Demographic data, types of pain distribution, responses of double controlled blocks, electrical stimulation parameters, numbers and levels of neurotomies, and surgical outcomes were evaluated after mean follow-up of 12 months. Pain distribution pattern was not significantly correlated with the results of diagnostic blocks. Average stimulation intensity was 0.45 V, ranging from 0.3 to 0.69, to elicit pain response in cervical medial branches. The most common involvement of nerve branches was C4 (89%), followed by C5 (82%), C6 (75%), and C7 (43%). Among total of 28 patients, nineteen (68%) reported successful outcome according to outcome criteria after 6 months of follow-up (p=0.001), and eight (42%) of 19 patients reported complete relief (100%) of pain. Four patients showed recurrence of pain between 6 and 12 months. It was therefore concluded that cervical medial branch neurotomy is considered useful therapeutic modality for the management of cervicobrachialgia in selected patients, particularly in degenerative zygapophyseal disorders. PMID:16479077

  2. Radiofrequency neurotomy of cervical medial branches for chronic cervicobrachialgia.

    PubMed

    Shin, Woo-Ram; Kim, Hyoung-Ihl; Shin, Dong-Gyu; Shin, Dong-Ah

    2006-02-01

    Chronic neck and arm pain or cervicobrachialgia commonly occurs with the degeneration of cervical spine. Authors investigated the usefulness of radiofrequency (RF) neurotomies of cervical medial branches in patients with cervicobrachialgia and analyzed the factors which can influence the treatment outcome. Demographic data, types of pain distribution, responses of double controlled blocks, electrical stimulation parameters, numbers and levels of neurotomies, and surgical outcomes were evaluated after mean follow-up of 12 months. Pain distribution pattern was not significantly correlated with the results of diagnostic blocks. Average stimulation intensity was 0.45 V, ranging from 0.3 to 0.69, to elicit pain response in cervical medial branches. The most common involvement of nerve branches was C4 (89%), followed by C5 (82%), C6 (75%), and C7 (43%). Among total of 28 patients, nineteen (68%) reported successful outcome according to outcome criteria after 6 months of followup (p=0.001), and eight (42%) of 19 patients reported complete relief (100%) of pain. Four patients showed recurrence of pain between 6 and 12 months. It was therefore concluded that cervical medial branch neurotomy is considered useful therapeutic modality for the management of cervicobrachialgia in selected patients, particularly in degenerative zygapophyseal disorders.

  3. Treatment of acne vulgaris with fractional radiofrequency microneedling.

    PubMed

    Kim, Sang Tae; Lee, Kang Hoon; Sim, Hyung Jun; Suh, Kee Suck; Jang, Min Soo

    2014-07-01

    Fractional radiofrequency microneedling is a novel radiofrequency technique that uses insulated microneedles to deliver energy to the deep dermis at the point of penetration without destruction of the epidermis. It has been used for the treatment of various dermatological conditions including wrinkles, atrophic scars and hypertrophic scars. There have been few studies evaluating the efficacy of fractional radiofrequency microneedling in the treatment of acne, and none measuring objective parameters like the number of inflammatory and non-inflammatory acne lesions or sebum excretion levels. The safety and efficacy of fractional radiofrequency microneedling in the treatment of acne vulgaris was investigated. In a prospective clinical trial, 25 patients with moderate to severe acne were treated with fractional radiofrequency microneedling. The procedure was carried out three times at 1-month intervals. Acne lesion count, subjective satisfaction score, sebum excretion level and adverse effects were assessed at baseline and at 4, 8 and 12 weeks after the first treatment as well as 4, 8 and 12 weeks after the last treatment. Number of acne lesions (inflammatory and non-inflammatory) decreased. Sebum excretion and subjective satisfaction were more favorable at every time point compared with the baseline values (P < 0.05). Inflammatory lesions responded better than non-inflammatory lesions (P < 0.05). Adverse effects such as pinpoint bleeding, pain and erythema were noted, but were transient and not severe enough to stop treatment. Fractional radiofrequency microneedling is a safe and effective treatment for acne vulgaris.

  4. Improvements in Intracorporeal Lithotripters for Percutaneous Nephrolithotomy

    NASA Astrophysics Data System (ADS)

    Kuo, Ramsay L.

    2007-04-01

    Percutaneous nephrolithotomy (PNL) is an effective minimally invasive surgical approach for the treatment of large renal stone burden. Intracorporeal lithotripters (ICL) are utilized during PNL to fragment calculi, with some devices capable of concurrently removing fragments as well. Much progress has been made in the design of ICL devices, resulting in potentially more efficient treatment of nephrolithiasis.

  5. Total Percutaneous Aortic Repair: Midterm Outcomes

    SciTech Connect

    Bent, Clare L. Fotiadis, Nikolas; Renfrew, Ian; Walsh, Michael; Brohi, Karim; Kyriakides, Constantinos; Matson, Matthew

    2009-05-15

    The purpose of this study was to examine the immediate and midterm outcomes of percutaneous endovascular repair of thoracic and abdominal aortic pathology. Between December 2003 and June 2005, 21 patients (mean age: 60.4 {+-} 17.1 years; 15 males, 6 females) underwent endovascular stent-graft insertion for thoracic (n = 13) or abdominal aortic (n = 8) pathology. Preprocedural computed tomographic angiography (CTA) was performed to assess the suitability of aorto-iliac and common femoral artery (CFA) anatomy, including the degree of CFA calcification, for total percutaneous aortic stent-graft repair. Percutaneous access was used for the introduction of 18- to 26-Fr delivery devices. A 'preclose' closure technique using two Perclose suture devices (Perclose A-T; Abbott Vascular) was used in all cases. Data were prospectively collected. Each CFA puncture site was assessed via clinical examination and CTA at 1, 6, and 12 months, followed by annual review thereafter. Minimum follow-up was 36 months. Outcome measures evaluated were rates of technical success, conversion to open surgical repair, complications, and late incidence of arterial stenosis at the site of Perclose suture deployment. A total of 58 Perclose devices were used to close 29 femoral arteriotomies. Outer diameters of stent-graft delivery devices used were 18 Fr (n = 5), 20 Fr (n = 3), 22 Fr (n = 4), 24 Fr (n = 15), and 26 Fr (n = 2). Percutaneous closure was successful in 96.6% (28/29) of arteriotomies. Conversion to surgical repair was required at one access site (3.4%). Mean follow-up was 50 {+-} 8 months. No late complications were observed. By CT criteria, no patient developed a >50% reduction in CFA caliber at the site of Perclose deployment during the study period. In conclusion, percutaneous aortic stent-graft insertion can be safely performed, with a low risk of both immediate and midterm access-related complications.

  6. Coal thickness gauge using RRAS techniques, part 1. [radiofrequency resonance absorption

    NASA Technical Reports Server (NTRS)

    Rollwitz, W. L.; King, J. D.

    1978-01-01

    A noncontacting sensor having a measurement range of 0 to 6 in or more, and with an accuracy of 0.5 in or better is needed to control the machinery used in modern coal mining so that the thickness of the coal layer remaining over the rock is maintained within selected bounds. The feasibility of using the radiofrequency resonance absorption (RRAS) techniques of electron magnetic resonance (EMR) and nuclear magnetic resonance (NMR) as the basis of a coal thickness gauge is discussed. The EMR technique was found, by analysis and experiments, to be well suited for this application.

  7. Ultrasonography-guided pulsed radiofrequency of sciatic nerve for the treatment of complex regional pain syndrome Type II

    PubMed Central

    Choi, Yi Hwa; Chang, Dong Jin; Hwang, Woon Suk; Chung, Jin Hwan

    2017-01-01

    Although the major mechanism of complex regional pain syndrome (CRPS) involves dysfunctional central or sympathetic nervous system activation, the peripheral nervous system also contributes significantly to its clinical manifestations. Pulsed radiofrequency (PRF) is a recently developed treatment option for neuropathic pain syndromes. Here, we report a case of CRPS Type II after a femur fracture and sciatic nerve injury, in which the pain was treated successfully with ultrasonography-guided selective sciatic nerve PRF application. PMID:28217060

  8. Intracellular hyperthermia mediated by nanoparticles in radiofrequency fields in the treatment of pancreatic cancer

    NASA Astrophysics Data System (ADS)

    Glazer, Evan Scott

    Intracellular hyperthermic therapy may prove to be a unique and novel approach to the management of pancreatic cancer. Utilizing the principle of photothermal destruction, selective killing of cancer cells with minimal injury to normal tissues may be possible. This dissertation investigated the role of antibody targeted metal nanoparticles and the cytotoxic effects of nonionizing radiofrequency fields in pancreatic cancer. Cancer cell death was induced by heat release from intracellular metal nanoparticles after radiofrequency field exposure. Fluorescent and gold nanoparticles were delivered with two antibodies, cetuximab and PAM-4, to pancreatic cancer cells in vitro and mouse xenografts in vivo. Selective delivery of these nanoparticles induced cell death in vitro and decreased tumor burden in vivo after whole animal RF field exposure. This occurred through both apoptosis and necrosis. In addition, activated caspase-3 was increased after antibody treatment and RF field exposure. Furthermore, although there was non-specific uptake by the liver and spleen in vivo, there was no evidence of acute or chronic toxicity in the animals. These results are in agreement with the principle that malignant cells are more thermally sensitive than normal cells or tissues. Selective intracellular delivery of metal nanoparticles coupled with whole body RF field exposure may be a beneficial therapy against micrometastases and unresectable pancreatic cancer in the future. Further studies are planned with more specific antibodies, other nanoparticles, and other cancer targets.

  9. Treatment of Infected Aneurysms of the Abdominal Aorta and Iliac Artery with Endovascular Aneurysm Repair and Percutaneous Drainage.

    PubMed

    Chino, Shuji; Kato, Noriyuki; Noda, Yoshihiro; Oue, Kensuke; Tanaka, Satofumi; Hashimoto, Takashi; Higashigawa, Takatoshi; Miyake, Yoichiro; Okabe, Manabu

    2016-10-01

    Infected aneurysm remains one of the most challenging diseases for vascular surgeons. We describe the successful treatment of 2 cases of infected aneurysms with endovascular aneurysm repair and percutaneous computed tomography-guided drainage. This strategy may be an effective alternative to open surgical repair in selected patients.

  10. Occlusive Peripheral Arteriosclerosis: Treatment by Percutaneous Transluminal Recanalization—“The Dotter Procedure”

    PubMed Central

    Palayew, M. J.; Sedlezky, I.; Sigman, H. H.; Sheiner, N. M.

    1969-01-01

    We have performed 17 percutaneous transluminal dilatations in 15 patients with segmental stenoses of the femoral and popliteal arteries. Initial success was achieved in 14 instances. This technique must be considered a useful adjunct in the treatment of peripheral vascular disease in selected patients. Its use along with endarterectomy has not been previously reported and warrants further investigation. ImagesFIG. 2FIG. 3FIG. 4FIG. 5FIG. 6FIG. 7FIG. 8FIG. 9FIG. 10FIG. 11 PMID:5353151

  11. Interval Biliary Stent Placement Via Percutaneous Ultrasound Guided Cholecystostomy: Another Approach to Palliative Treatment in Malignant Biliary Tract Obstruction

    SciTech Connect

    Harding, James Mortimer, Alex; Kelly, Michael; Loveday, Eric

    2010-12-15

    Percutaneous cholecystostomy is a minimally invasive procedure for providing gallbladder decompression, often in critically ill patients. It can be used in malignant biliary obstruction following failed endoscopic retrograde cholangiopancreatography when the intrahepatic ducts are not dilated or when stent insertion is not possible via the bile ducts. In properly selected patients, percutaneous cholecystostomy in obstructive jaundice is a simple, safe, and rapid option for biliary decompression, thus avoiding the morbidity and mortality involved with percutaneous transhepatic biliary stenting. Subsequent use of a percutaneous cholecystostomy for definitive biliary stent placement is an attractive concept and leaves patients with no external drain. To the best of our knowledge, it has only been described on three previous occasions in the published literature, on each occasion forced by surgical or technical considerations. Traditionally, anatomic/technical considerations and the risk of bile leak have precluded such an approach, but improvements in catheter design and manufacture may now make it more feasible. We report a case of successful interval metal stent placement via percutaneous cholecystostomy which was preplanned and achieved excellent palliation for the patient. The pros and cons of the procedure and approach are discussed.

  12. Percutaneous endoscopic gastrostomy tube replacement unexpected serious events.

    PubMed

    Triantafyllou, Konstantinos; Papanikolaou, Ioannis S; Stasinos, Ioannis; Polymeros, Dimitrios; Dimitriadis, George D

    2014-02-01

    Percutaneous endoscopic gastrostomy tubes are replaced due to clogging, breaking, and dislodgement. There are potential complications associated with these procedures, including intraperitoneal placement of the tube and peritonitis, which can occur even in the presence of a well established stoma site. Herein we present a case series of 3 patients with mature gastrocutaneous tracks, who developed peritonitis following tube replacement. In the absence of a consensus or international guidelines regarding the management of patients requiring percoutaneous endoscopic gastrostomy tube replacement, emphasis should be given on prevention of severe adverse events and on early anticipation of their occurrence. Clinical experience indicates that recognition of high-risk procedures, selection of the appropriate replacement method and confirmation of correct tube placement can improve patients' safety and reduce the complications rate.

  13. MR-Guided Percutaneous Angioplasty: Assessment of Tracking Safety, Catheter Handling and Functionality

    SciTech Connect

    Wildermuth, Simon; Dumoulin, Charles L.; Pfammatter, Thomas; Maier, Stephan E.; Hofmann, Eugen; Debatin, Joerg F.

    1998-09-15

    Purpose: Magnetic resonance (MR)-guided percutaneous vascular interventions have evolved to a practical possibility with the advent of open-configuration MR systems and real-time tracking techniques. The purpose of this study was to assess an MR-tracking percutaneous transluminal angioplasty (PTA) catheter with regard to its safety profile and functionality. Methods: Real-time, biplanar tracking of the PTA catheter was made possible by incorporating a small radiofrequency (RF) coil in the catheter tip and connecting it to a coaxial cable embedded in the catheter wall. To evaluate potentially hazardous thermal effects due to the incorporation of the coil, temperature measurements were performed within and around the coil under various scanning and tracking conditions at 1.5 Tesla (T). Catheter force transmission and balloon-burst pressure of the MR-tracking PTA catheter were compared with those of a standard PTA catheter. The dilatative capability of the angioplasty balloon was assessed in vitro as well as in vivo, in an isolated femoral artery segment in a swine. Results: The degree of heating at the RF coil was directly proportional to the power of the RF pulses. Heating was negligible with MR tracking, conventional spin-echo and low-flip gradient-echo sequences. Sequences with higher duty cycles, such as fast spin echo, produced harmful heating effects. Force transmission of the MR-tracking PTA catheter was slightly inferior to that of the standard PTA catheter, while balloon-burst pressures were similar to those of conventional catheters. The MR-tracking PTA catheter functioned well both in vitro and in vivo. Conclusion: The in vivo use of an MR-tracking PTA catheter is safe under most scanning conditions.

  14. Long-Term Outcome of a Hepatocellular Carcinoma 71/2 Years After Surgery and Repeated Radiofrequency Ablation: Case Report and Review of the Literature

    SciTech Connect

    Thanos, L. Mylona, S.; Nikita, A.; Ptohis, N.; Kelekis, D.A.

    2007-04-15

    An interesting case is presented of a 78-year-old patient with cirrhosis who was managed with combined treatment (surgery and radiofrequency (RF) ablation) for hepatocellular carcinoma (HCC) and has survived for 71/2 years. Elevation of the {alpha}-FP (alpha-fetoprotein) levels was noted 2 years after surgery. CT demonstrated two lesions: one central at the remaining right liver lobe, and the other at the excision site. Biopsy of the lesions confirmed the diagnosis of HCC for both of them. RF ablation of these two lesions was performed in one session with technical success. Four and a half years after the first RF ablation a new recurrence was demonstrated at the CT follow-up control. RF ablation was again applied successfully. The imaging findings and the therapeutic percutaneous management of this patient along with the natural course of HCC and its recurrence are discussed, and the literature concerning risk factors is reviewed.

  15. Near-field radiofrequency electromagnetic exposure assessment.

    PubMed

    Rubtsova, Nina; Perov, Sergey; Belaya, Olga; Kuster, Niels; Balzano, Quirino

    2015-09-01

    Personal wireless telecommunication devices, such as radiofrequency (RF) electromagnetic field (EMF) sources operated in vicinity of human body, have possible adverse health effects. Therefore, the correct EMF assessment is necessary in their near field. According to international near-field measurement criteria, the specific absorption rate (SAR) is used for absorbed energy distribution assessment in tissue simulating liquid phantoms. The aim of this investigation is to validate the relationship between the H-field of incident EMF and absorbed energy in phantoms. Three typical wireless telecommunication system frequencies are considered (900, 1800 and 2450 MHz). The EMF source at each frequency is an appropriate half-wave dipole antenna and the absorbing medium is a flat phantom filled with the suitable tissue simulating liquid. Two methods for SAR estimation have been used: standard procedure based on E-field measured in tissue simulating medium and a proposed evaluation by measuring the incident H-field. Compared SAR estimations were performed for various distances between sources and phantom. Also, these research data were compared with simulation results, obtained by using finite-difference time-domain method. The acquired data help to determine the source near-field space characterized by the smallest deviation between SAR estimation methods. So, this region near the RF source is suitable for correct RF energy absorption assessment using the magnetic component of the RF fields.

  16. Micro pulsed radio-frequency electroporation chips.

    PubMed

    He, Huiqi; Chang, Donald C; Lee, Yi-Kuen

    2006-01-01

    Electroporation (EP) is one of the most important physical methods in biotechnology, which employs electrical pulses to transiently permeabilize cell membranes. In this study, a new micro pulsed radio-frequency electroporation cell (microPREP) chip was fabricated using a lift-off technique and SU-8 photolithography. The biological tests were carried out using three different plant protoplasts (cabbage, spinach and oil rape) on the micro EP chip and a pulsed RF electric field was applied to the microchip. The variations of fluorescent intensity and cell viability as functions of the electric pulse amplitude and duration time during the electroporation process were studied in detail at the single-cell level. Using such chip design and test method, one can easily optimize the efficiency and cell viability. Also, a large amount of statistical data can be quickly obtained. Finally, results of this parametric study were presented in the "phase diagram", from which the critical electric field for inducing single-cell electroporation under different conditions can be clearly determined.

  17. Radiofrequency Heating Pathways for Gold Nanoparticles

    PubMed Central

    Collins, C. B.; McCoy, R. S.; Ackerson, B. J.; Collins, G. J.

    2015-01-01

    This feature article reviews the thermal dissipation of nanoscopic gold under radiofrequency (RF) irradiation. It also presents previously unpublished data addressing obscure aspects of this phenomenon. While applications in biology motivated initial investigation of RF heating of gold nanoparticles, recent controversy concerning whether thermal effects can be attributed to nanoscopic gold highlight the need to understand the involved mechanism or mechanisms of heating. Both the nature of the particle and the nature of the RF field influence heating. Aspects of nanoparticle chemistry and physics, including the hydrodynamic diameter of the particle, the oxidation state and related magnetism of the core, and the chemical nature of the ligand shell may all strongly influence to what extent a nanoparticle heats in an RF field. Aspects of RF include: power, frequency and antenna designs that emphasize relative strength of magnetic or electric fields, and also influence the extent to which a gold nanoparticle heats in RF. These nanoparticle and RF properties are analysed in the context of three heating mechanisms proposed to explain gold nanoparticle heating in an RF field. This article also makes a critical analysis of the existing literature in the context of the nanoparticle preparations, RF structure, and suggested mechanisms in previously reported experiments. PMID:24962620

  18. Epidemiology of Health Effects of Radiofrequency Exposure

    PubMed Central

    Ahlbom, Anders; Green, Adele; Kheifets, Leeka; Savitz, David; Swerdlow, Anthony

    2004-01-01

    We have undertaken a comprehensive review of epidemiologic studies about the effects of radiofrequency fields (RFs) on human health in order to summarize the current state of knowledge, explain the methodologic issues that are involved, and aid in the planning of future studies. There have been a large number of occupational studies over several decades, particularly on cancer, cardiovascular disease, adverse reproductive outcome, and cataract, in relation to RF exposure. More recently, there have been studies of residential exposure, mainly from radio and television transmitters, and especially focusing on leukemia. There have also been studies of mobile telephone users, particularly on brain tumors and less often on other cancers and on symptoms. Results of these studies to date give no consistent or convincing evidence of a causal relation between RF exposure and any adverse health effect. On the other hand, the studies have too many deficiencies to rule out an association. A key concern across all studies is the quality of assessment of RF exposure. Despite the ubiquity of new technologies using RFs, little is known about population exposure from RF sources and even less about the relative importance of different sources. Other cautions are that mobile phone studies to date have been able to address only relatively short lag periods, that almost no data are available on the consequences of childhood exposure, and that published data largely concentrate on a small number of outcomes, especially brain tumor and leukemia. PMID:15579422

  19. Directional Radio-Frequency Identification Tag Reader

    NASA Technical Reports Server (NTRS)

    Medelius, Pedro J.; Taylor, John D.; Henderson, John J.

    2004-01-01

    A directional radio-frequency identification (RFID) tag reader has been designed to facilitate finding a specific object among many objects in a crowded room. The device could be an adjunct to an electronic inventory system that tracks RFID-tagged objects as they move through reader-equipped doorways. Whereas commercial RFID-tag readers do not measure directions to tagged objects, the device is equipped with a phased-array antenna and a received signal-strength indicator (RSSI) circuit for measuring direction. At the beginning of operation, it is set to address only the RFID tag of interest. It then continuously transmits a signal to interrogate that tag while varying the radiation pattern of the antenna. It identifies the direction to the tag as the radiation pattern direction of peak strength of the signal returned by the tag. An approximate distance to the tag is calculated from the peak signal strength. The direction and distance can be displayed on a screen. A prototype containing a Yagi antenna was found to be capable of detecting a 915.5-MHz tag at a distance of approximately equal to 15 ft (approximately equal to 4.6 m).

  20. Electromagnetic limits to radiofrequency (RF) neuronal telemetry

    PubMed Central

    Diaz, R. E.; Sebastian, T.

    2013-01-01

    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. PMID:24346503

  1. Radiofrequency treatment alters cancer cell phenotype

    PubMed Central

    Ware, Matthew J.; Tinger, Sophia; Colbert, Kevin L.; Corr, Stuart J.; Rees, Paul; Koshkina, Nadezhda; Curley, Steven; Summers, H. D.; Godin, Biana

    2015-01-01

    The importance of evaluating physical cues in cancer research is gradually being realized. Assessment of cancer cell physical appearance, or phenotype, may provide information on changes in cellular behavior, including migratory or communicative changes. These characteristics are intrinsically different between malignant and non-malignant cells and change in response to therapy or in the progression of the disease. Here, we report that pancreatic cancer cell phenotype was altered in response to a physical method for cancer therapy, a non-invasive radiofrequency (RF) treatment, which is currently being developed for human trials. We provide a battery of tests to explore these phenotype characteristics. Our data show that cell topography, morphology, motility, adhesion and division change as a result of the treatment. These may have consequences for tissue architecture, for diffusion of anti-cancer therapeutics and cancer cell susceptibility within the tumor. Clear phenotypical differences were observed between cancerous and normal cells in both their untreated states and in their response to RF therapy. We also report, for the first time, a transfer of microsized particles through tunneling nanotubes, which were produced by cancer cells in response to RF therapy. Additionally, we provide evidence that various sub-populations of cancer cells heterogeneously respond to RF treatment. PMID:26165830

  2. Radiofrequency treatment alters cancer cell phenotype

    NASA Astrophysics Data System (ADS)

    Ware, Matthew J.; Tinger, Sophia; Colbert, Kevin L.; Corr, Stuart J.; Rees, Paul; Koshkina, Nadezhda; Curley, Steven; Summers, H. D.; Godin, Biana

    2015-07-01

    The importance of evaluating physical cues in cancer research is gradually being realized. Assessment of cancer cell physical appearance, or phenotype, may provide information on changes in cellular behavior, including migratory or communicative changes. These characteristics are intrinsically different between malignant and non-malignant cells and change in response to therapy or in the progression of the disease. Here, we report that pancreatic cancer cell phenotype was altered in response to a physical method for cancer therapy, a non-invasive radiofrequency (RF) treatment, which is currently being developed for human trials. We provide a battery of tests to explore these phenotype characteristics. Our data show that cell topography, morphology, motility, adhesion and division change as a result of the treatment. These may have consequences for tissue architecture, for diffusion of anti-cancer therapeutics and cancer cell susceptibility within the tumor. Clear phenotypical differences were observed between cancerous and normal cells in both their untreated states and in their response to RF therapy. We also report, for the first time, a transfer of microsized particles through tunneling nanotubes, which were produced by cancer cells in response to RF therapy. Additionally, we provide evidence that various sub-populations of cancer cells heterogeneously respond to RF treatment.

  3. Radiofrequency radiation effects on the common bean

    SciTech Connect

    Thomkins, K.; Griggs, L.; Myles, E.L.

    1995-07-01

    Our environment is bombarded daily with thousands of objects we can visually detect. However, invisible to humans are the electromagnetic waves that penetrate our environment. Electromagnetic waves consist of a large spectrum of waves including the harmful gamma rays, x-rays, and ultraviolet rays. The question that has increased tremendously is: can low energy electromagnetic waves become harmful to living organisms? The purpose of this study is to determine the effect of radiofrequency radiation on protein synthesis of the common bean. Phaseolus vulgaris (kidney bean) was surface-sterilized and allowed to germinate on Mushurage and Skoog`s medium for 1 week. Hypocotyls were wounded and placed on media to initiate callus production. Six petri dishes containing 1 g of callus were used in the experiment. Three dishes were exposed to 100kH in a Crawford cell for 24h. The remaining three petri dishes with callus were used as a control. After the exposure period, the protein from callus was extracted and analyzed by one-dimensional gel electrophoresis. The results show that hypocotyl growth was not different between control and experimental groups after 24 h. The result of one-dimensional gel electrophoresis did not show observable differences in protein synthesized by the control and experimental groups. Analysis of protein synthesis is still ongoing.

  4. Percutaneous and combined percutaneous and intralesional Nd:YAG-laser therapy for vascular malformations.

    PubMed

    Wimmershoff, M B; Landthaler, M; Hohenleutner, U

    1999-01-01

    The numerous types of vascular abnormality are classified in groups according to their pathological and anatomical features. We present case histories of 2 patients who had vascular malformations of the face since birth or early childhood. Application methods, side-effects and complications of percutaneous and intra-lesional Nd:YAG-laser therapy are reviewed for these patients. A 54-year-old woman was treated percutaneously with the Nd: YAG-laser at 1064 nm, with 20 30 W, cw 1-5 s pulses and 2 - 3 mm spot size. A 59-year-old woman was treated with the combined percutaneous and intralesional laser therapy with 30 W, cw 1-5 s pulses and 2-3 mm spot size. In both cases, percutaneous or combined percutaneous and intra-lesional Nd: YAG-laser application resulted in a significant shrinking of the lesion. The Nd:YAG-laser radiation at 1064 nm presents an effective treatment of vascular malformations due to its deep penetration into the tissue. No standardized guidelines for Nd: YAG-laser therapy exist and the treatment parameters should be chosen individually according to the type of vascular malformation.

  5. Continuous Cavitation Designed for Enhancing Radiofrequency Ablation via a Special Radiofrequency Solidoid Vaporization Process.

    PubMed

    Zhang, Kun; Li, Pei; Chen, Hangrong; Bo, Xiaowan; Li, Xiaolong; Xu, Huixiong

    2016-02-23

    Lowering power output and radiation time during radiofrequency (RF) ablation is still a challenge. Although it is documented that metal-based magnetothermal conversion and microbubbles-based inertial cavitation have been tried to overcome above issues, disputed toxicity and poor magnetothermal conversion efficiency for metal-based nanoparticles and violent but transient cavitation for microbubbles are inappropriate for enhancing RF ablation. In this report, a strategy, i.e., continuous cavitation, has been proposed, and solid menthol-encapsulated poly lactide-glycolide acid (PLGA) nanocapsules have been constructed, as a proof of concept, to validate the role of such a continuous cavitation principle in continuously enhancing RF ablation. The synthesized PLGA-based nanocapsules can respond to RF to generate menthol bubbles via distinctive radiofrequency solidoid vaporization (RSV) process, meanwhile significantly enhance ultrasound imaging for HeLa solid tumor, and further facilitate RF ablation via the continuous cavitation, as systematically demonstrated both in vitro and in vivo. Importantly, this RSV strategy can overcome drawbacks and limitations of acoustic droplet vaporization (ADV) and optical droplet vaporization (ODV), and will probably find broad applications in further cancer theranostics.

  6. Intermediate-term results of partial plantar fascia release with microtenotomy using bipolar radiofrequency microtenotomy.

    PubMed

    Lucas, Douglas E; Ekroth, Scott R; Hyer, Christopher F

    2015-01-01

    Plantar fasciitis is a common condition, with most patients treated successfully with nonoperative management. Recalcitrant disease has been managed with surgical procedures that vary in design and associated morbidity. The present study sought to determine the intermediate-term results of percutaneous bipolar radiofrequency microtenotomy in recalcitrant plantar fasciitis. The patient medical records were reviewed, and data were gathered for all the patients who met the inclusion criteria. The foot function index and visual analog scale (VAS) pain scale questionnaires were mailed to the 111 patients. Of the 111 patients, 61 (55.0%) returned their questionnaires and were ultimately included in the present analysis. Of the 61 patients, 44 (72.1%) were female and 17 were (27.9%) male, with an average reported follow-up of 33.3 ± 8.6 (range 16.1 to 46.6) months. The median postoperative VAS score was 0.0 (range 0.0 to 10.0), and the median foot function index score was 3.1 (range 0.0 to 97.1). The patients were subdivided into success and failure groups according to their satisfaction. Of the 61 patients, 51 (83.6%) were satisfied and would recommend the procedure to a friend. The median VAS score in the success group was 0.0 (range 0.0 to 5.0), and the median VAS score in the failure group was 6.0 (range 0.0 to 10.0), a significant difference (p < .001). A significant difference was also seen in the foot function index score between the success (median 2.4, range 0.0 to 25.7) and failure (median 37.4, range 0.0 to 97.1) groups (p < .001). Bipolar radiofrequency microtenotomy appears to be a safe procedure that can provide outcomes equivalent to those with open surgery, with less morbidity, for recalcitrant plantar fasciitis.

  7. A Rare Complication of Radiofrequency Tonsil Ablation: Horner Syndrome

    PubMed Central

    Ozbay, Isa; Yildirim, Nadir; Zeybek Sivas, Zuhal; Canbaz Kabay, Sibel

    2015-01-01

    Chronic tonsillitis is a common disease, and several different surgical techniques are used to treat this condition. In recent years, techniques such as radiofrequency ablation and coblation have been commonly used for tonsil surgery. In this report, we present the cases of two pediatric patients who developed ptosis, miosis, and enophthalmos (Horner syndrome) after radiofrequency ablation for tonsil reduction and discuss the technique of radiofrequency ablation of the tonsils. In the early postoperative period, miosis and ptosis were observed on the right side in one patient and on the left side in the other patient. Both patients were treated with 1 mg/kg/day methylprednisolone, which were tapered by halving the dose every 3 days. Miosis and ptosis improved after treatment in both patients. Along with the case presentation, we discuss the effectiveness and complications of radiofrequency ablation of the tonsils. These unusual complications of tonsil ablation may help ENT physicians who do not yet have a preferred surgical technique for tonsillectomy to make an informed decision. Limited data are available about the possible complications of radiofrequency ablation of the tonsils. The present report contributes to the literature on this topic. PMID:26064747

  8. Magnetoreception in birds: the effect of radio-frequency fields

    PubMed Central

    Wiltschko, Roswitha; Thalau, Peter; Gehring, Dennis; Nießner, Christine; Ritz, Thorsten; Wiltschko, Wolfgang

    2015-01-01

    The avian magnetic compass, probably based on radical pair processes, works only in a narrow functional window around the local field strength, with cryptochrome 1a as most likely receptor molecule. Radio-frequency fields in the MHz range have been shown to disrupt the birds' orientation, yet the nature of this interference is still unclear. In an immuno-histological study, we tested whether the radio-frequency fields interfere with the photoreduction of cryptochrome, but this does not seem to be the case. In behavioural studies, birds were not able to adjust to radio-frequency fields like they are able to adjust to static fields outside the normal functional range: neither a 2-h pre-exposure in a 7.0 MHz field, 480 nT, nor a 7-h pre-exposure in a 1.315 MHz field, 15 nT, allowed the birds to regain their orientation ability. This inability to adjust to radio-frequency fields suggests that these fields interfere directly with the primary processes of magnetoreception and therefore disable the avian compass as long as they are present. They do not have lasting adverse after-effects, however, as birds immediately after exposure to a radio-frequency field were able to orient in the local geomagnetic field. PMID:25540238

  9. Magnetoreception in birds: the effect of radio-frequency fields.

    PubMed

    Wiltschko, Roswitha; Thalau, Peter; Gehring, Dennis; Nießner, Christine; Ritz, Thorsten; Wiltschko, Wolfgang

    2015-02-06

    The avian magnetic compass, probably based on radical pair processes, works only in a narrow functional window around the local field strength, with cryptochrome 1a as most likely receptor molecule. Radio-frequency fields in the MHz range have been shown to disrupt the birds' orientation, yet the nature of this interference is still unclear. In an immuno-histological study, we tested whether the radio-frequency fields interfere with the photoreduction of cryptochrome, but this does not seem to be the case. In behavioural studies, birds were not able to adjust to radio-frequency fields like they are able to adjust to static fields outside the normal functional range: neither a 2-h pre-exposure in a 7.0 MHz field, 480 nT, nor a 7-h pre-exposure in a 1.315 MHz field, 15 nT, allowed the birds to regain their orientation ability. This inability to adjust to radio-frequency fields suggests that these fields interfere directly with the primary processes of magnetoreception and therefore disable the avian compass as long as they are present. They do not have lasting adverse after-effects, however, as birds immediately after exposure to a radio-frequency field were able to orient in the local geomagnetic field.

  10. Brachiocephalic artery haemorrhage during percutaneous tracheostomy.

    PubMed

    Sharma, S D; Kumar, G; Hill, C S; Kaddour, H

    2015-03-01

    Percutaneous tracheostomy was performed on a 69-year-old woman to facilitate weaning. Insertion of the size 7 tracheostomy tube resulted in profuse bleeding around the tracheostomy site. On inflation of the tracheostomy balloon, the bleeding stopped. Urgent computed tomography demonstrated the brachiocephalic artery was abnormally high and lying in an oblique fashion over the trachea, and the tracheostomy tube was displacing the trachea posteriorly. Surgical repair of the defect in the brachiocephalic artery was undertaken and a surgical tracheostomy was performed in theatre. This case raises important issues about the potential dangers of percutaneous tracheostomy in cases of abnormal anatomy. It also emphasises the importance of direct visualisation of the seeker needle using the endoscope. In cases where there is a suspicion of abnormal anatomy, it is safer to obtain preprocedural imaging or perform a surgical tracheostomy.

  11. Brachiocephalic Artery Haemorrhage During Percutaneous Tracheostomy

    PubMed Central

    Kumar, G; Hill, CS; Kaddour, H

    2015-01-01

    Percutaneous tracheostomy was performed on a 69-year-old woman to facilitate weaning. Insertion of the size 7 tracheostomy tube resulted in profuse bleeding around the tracheostomy site. On inflation of the tracheostomy balloon, the bleeding stopped. Urgent computed tomography demonstrated the brachiocephalic artery was abnormally high and lying in an oblique fashion over the trachea, and the tracheostomy tube was displacing the trachea posteriorly. Surgical repair of the defect in the brachiocephalic artery was undertaken and a surgical tracheostomy was performed in theatre. This case raises important issues about the potential dangers of percutaneous tracheostomy in cases of abnormal anatomy. It also emphasises the importance of direct visualisation of the seeker needle using the endoscope. In cases where there is a suspicion of abnormal anatomy, it is safer to obtain preprocedural imaging or perform a surgical tracheostomy. PMID:25723674

  12. Risk scoring for percutaneous coronary intervention: let's do it!

    PubMed Central

    Siotia, A

    2006-01-01

    The recent publication of a robust percutaneous coronary intervention (PCI) risk scoring system should stimulate every interventional cardiologist to incorporate risk adjustment into their everyday practice PMID:16621880

  13. MATHEMATICAL MODELS FOR SOME RADIO-FREQUENCY TRANSMISSION-LINE TRANSFORMERS

    DTIC Science & Technology

    MATRICES(MATHEMATICS), *PHASE SHIFT CIRCUITS, *RADIOFREQUENCY, *TRANSFORMERS, *TRANSMISSION LINES, BROADBAND, DIELECTRIC PROPERTIES, ELECTRICAL IMPEDANCE, FERRITES, IMPEDANCE MATCHING , MATHEMATICAL ANALYSIS.

  14. Are we fearful of tubeless percutaneous nephrolithotomy? Assessing the need for tube drainage following percutaneous nephrolithotomy

    PubMed Central

    Abbott, Joel E.; Deem, Samuel G.; Mosley, Natalie; Tan, Gary; Kumar, Nathan; Davalos, Julio G.

    2016-01-01

    Objective: The objective was to demonstrate that percutaneous nephrolithotomy (PCNL) can be safely performed with a tubeless or totally tubeless drainage technique. Introduction: Standard PCNL includes nephrostomy tube placement designed to drain the kidney and operative tract at the conclusion of the procedure. Modern technique trend is tubeless PCNL and totally tubeless PCNL, which are performed without standard nephrostomy drainage. We aim to reinforce current literature in demonstrating that PCNL can be safely performed using a tubeless technique. With compounded supportive data, we can help generate a trend toward a more cost-effective procedure with improved pain profiles and patient satisfaction, as previously shown with the tubeless technique. Methods: Retrospective analysis of 165 patients who underwent PCNL treatment was performed. Of this group, 127 patients underwent traditional nephrostomy drainage following PCNL. A tubeless procedure was performed in the remaining 38 patients. Patient's postoperative stone size and burden as well as complication profiles were analyzed. Largest stone size and total stone burden was similar between the groups. Results: Patient characteristics and demographic information were compared and no significant statistical difference was identified between the groups. Complication rates between the groups were compared and no statistical difference was noted. A total of 23 patients had at least one postoperative complication. Conclusion: Tubeless and totally tubeless PCNL demonstrates equivalent outcomes in the properly selected patient group when compared to PCNL performed with a nephrostomy tube. Although this is not the first study to demonstrate this, a large majority of urologists continue standard nephrostomy placement after PCNL. More studies are needed that demonstrate safety of this practice to shift the pendulum of care. Thus, tubeless and totally tubeless PCNL can be performed safely and effectively, which has

  15. Percutaneous Vertebral Body Augmentation: An Updated Review

    PubMed Central

    Omidi-Kashani, Farzad

    2014-01-01

    There are many medical conditions like osteoporosis, tumor, or osteonecrosis that weaken the structural strength of the vertebral body and prone it to fracture. Percutaneous vertebral augmentation that is usually applied by polymethylmethacrylate is a relatively safe, effective, and long lasting procedure commonly performed in these situations. In this paper, we updated a review of biomechanics, indications, contraindications, surgical techniques, complications, and overall prognosis of these minimally invasive spinal procedures. PMID:25379561

  16. Transdermal anaesthesia for percutaneous trigger finger release.

    PubMed

    Yiannakopoulos, Christos K; Ignatiadis, Ioannis A

    2006-01-01

    The purpose of this study was to evaluate the safety and efficiency of transdermal anaesthesia using eutectic mixture of lidocaine and prilocaine (EMLA) in patients undergoing percutaneous trigger finger release and to compare it with lidocaine infiltration. In this prospective, randomised study percutaneous release of the A1 annular pulley was performed to treat stenosing tenosynovitis (trigger finger syndrome) in 50 patients (50 fingers). The procedure was performed either under transdermal anaesthesia using EMLA applied transcutaneously 120 minutes prior to the operation (Group A, n = 25) or using local infiltration anaesthesia using lidocaine (Group B, n = 25). Pain experienced during administration of anaesthesia and during the operation was assessed using a 10-point Visual Analogue Pain Scale (VAPS), while all patients rated the effectiveness of anaesthesia with a 5-point scale. There were no significant differences between the two groups in the VAPS during the operation (1.33 +/- 0.52 versus 1.59 +/- 0.87) and the satisfaction scores (4.6 +/- 0.2 versus 4.4 +/- 0.3). The VAPS score during the administration of anaesthesia was statistically significantly less in the EMLA group (0 versus 5.96 +/- 2.41). All patients were satisfied with the final result of the operation. Percutaneous trigger finger release can be performed as an office procedure with the use of EMLA avoiding the use of injectable local infiltration anaesthesia.

  17. Percutaneous Zenith endografting for abdominal aortic aneurysms.

    PubMed

    Heyer, Kamaldeep S; Resnick, Scott A; Matsumura, Jon S; Amaranto, Daniel; Eskandari, Mark K

    2009-03-01

    A completely percutaneous approach to infrarenal abdominal aortic aneurysm (AAA) endografting has the theoretic benefits of being minimally invasive and more expedient. Our goal was to demonstrate the utility of this approach using a suprarenal fixation device and a suture-mediated closure system. We conducted a single-institution, retrospective review of 14 patients who underwent percutaneous AAA repair with the Zenith device between August 2003 and March 2007. Immediate and delayed access-related outcomes were examined over a mean follow-up of 12.1+/-2.0 months. Mean AAA size was 5.6 cm. Immediate arterial closure and technical success rate was 96% (27/28 vessels). One immediate hemostatic failure required open surgical repair. Over follow-up, one vessel required operative repair for new-onset claudication. No other immediate or delayed complications (thrombosis, pseudoaneurysm, infection, or deep venous thrombosis) were detected. A percutaneous approach for the treatment of AAA has several advantages over femoral artery cutdown but also has its own unique set of risks in the immediate and late postoperative period. Ultimately, the "preclose technique" can be safely applied for the Zenith device despite its large-bore delivery system.

  18. Percutaneous Cryoablation for Renal Cell Carcinoma

    PubMed Central

    Georgiades, Christos

    2015-01-01

    Renal cell carcinoma (RCC) is the most common type of kidney cancer in adults. Nephron sparing resection (partial nephrectomy) has been the “gold standard” for the treatment of resectable disease. With the widespread use of cross sectional imaging techniques, more cases of renal cell cancers are detected at an early stage, i.e. stage 1A or 1B. This has provided an impetus for expanding the nephron sparing options and especially, percutaneous ablative techniques. Percutaneous ablation for RCC is now performed as a standard therapeutic nephron-sparing option in patients who are poor candidates for resection or when there is a need to preserve renal function due to comorbid conditions, multiple renal cell carcinomas, and/or heritable renal cancer syndromes. During the last few years, percutaneous cryoablation has been gaining acceptance as a curative treatment option for small renal cancers. Clinical studies to date indicate that cryoablation is a safe and effective therapeutic method with acceptable short and long term outcomes and with a low risk, in the appropriate setting. In addition it seems to offer some advantages over radio frequency ablation (RFA) and other thermal ablation techniques for renal masses.

  19. 21 CFR 179.30 - Radiofrequency radiation for the heating of food, including microwave frequencies.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Radiofrequency radiation for the heating of food... PRODUCTION, PROCESSING AND HANDLING OF FOOD Radiation and Radiation Sources § 179.30 Radiofrequency radiation for the heating of food, including microwave frequencies. Radiofrequency radiation,...

  20. 21 CFR 179.30 - Radiofrequency radiation for the heating of food, including microwave frequencies.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Radiofrequency radiation for the heating of food... FOOD Radiation and Radiation Sources § 179.30 Radiofrequency radiation for the heating of food, including microwave frequencies. Radiofrequency radiation, including microwave frequencies, may be...

  1. 21 CFR 179.30 - Radiofrequency radiation for the heating of food, including microwave frequencies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Radiofrequency radiation for the heating of food... PRODUCTION, PROCESSING AND HANDLING OF FOOD Radiation and Radiation Sources § 179.30 Radiofrequency radiation for the heating of food, including microwave frequencies. Radiofrequency radiation,...

  2. 21 CFR 179.30 - Radiofrequency radiation for the heating of food, including microwave frequencies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Radiofrequency radiation for the heating of food... PRODUCTION, PROCESSING AND HANDLING OF FOOD Radiation and Radiation Sources § 179.30 Radiofrequency radiation for the heating of food, including microwave frequencies. Radiofrequency radiation,...

  3. 21 CFR 179.30 - Radiofrequency radiation for the heating of food, including microwave frequencies.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Radiofrequency radiation for the heating of food... PRODUCTION, PROCESSING AND HANDLING OF FOOD Radiation and Radiation Sources § 179.30 Radiofrequency radiation for the heating of food, including microwave frequencies. Radiofrequency radiation,...

  4. 21 CFR 870.2910 - Radiofrequency physiological signal transmitter and receiver.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiofrequency physiological signal transmitter... Devices § 870.2910 Radiofrequency physiological signal transmitter and receiver. (a) Identification. A radiofrequency physiological signal transmitter and receiver is a device used to condition a physiological...

  5. 21 CFR 870.2910 - Radiofrequency physiological signal transmitter and receiver.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radiofrequency physiological signal transmitter... Devices § 870.2910 Radiofrequency physiological signal transmitter and receiver. (a) Identification. A radiofrequency physiological signal transmitter and receiver is a device used to condition a physiological...

  6. 21 CFR 870.2910 - Radiofrequency physiological signal transmitter and receiver.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radiofrequency physiological signal transmitter... Devices § 870.2910 Radiofrequency physiological signal transmitter and receiver. (a) Identification. A radiofrequency physiological signal transmitter and receiver is a device used to condition a physiological...

  7. 21 CFR 870.2910 - Radiofrequency physiological signal transmitter and receiver.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radiofrequency physiological signal transmitter... Devices § 870.2910 Radiofrequency physiological signal transmitter and receiver. (a) Identification. A radiofrequency physiological signal transmitter and receiver is a device used to condition a physiological...

  8. 21 CFR 870.2910 - Radiofrequency physiological signal transmitter and receiver.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency physiological signal transmitter... Devices § 870.2910 Radiofrequency physiological signal transmitter and receiver. (a) Identification. A radiofrequency physiological signal transmitter and receiver is a device used to condition a physiological...

  9. 21 CFR 880.6300 - Implantable radiofrequency transponder system for patient identification and health information.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... radiofrequency transponder system for patient identification and health information. (a) Identification. An implantable radiofrequency transponder system for patient identification and health information is a device... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Implantable radiofrequency transponder system...

  10. 21 CFR 880.6300 - Implantable radiofrequency transponder system for patient identification and health information.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... radiofrequency transponder system for patient identification and health information. (a) Identification. An implantable radiofrequency transponder system for patient identification and health information is a device... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Implantable radiofrequency transponder system...

  11. 21 CFR 880.6300 - Implantable radiofrequency transponder system for patient identification and health information.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... radiofrequency transponder system for patient identification and health information. (a) Identification. An implantable radiofrequency transponder system for patient identification and health information is a device... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Implantable radiofrequency transponder system...

  12. 21 CFR 880.6300 - Implantable radiofrequency transponder system for patient identification and health information.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... radiofrequency transponder system for patient identification and health information. (a) Identification. An implantable radiofrequency transponder system for patient identification and health information is a device... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Implantable radiofrequency transponder system...

  13. 21 CFR 880.6300 - Implantable radiofrequency transponder system for patient identification and health information.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... radiofrequency transponder system for patient identification and health information. (a) Identification. An implantable radiofrequency transponder system for patient identification and health information is a device... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Implantable radiofrequency transponder system...

  14. Influence of radiofrequency surgery on architecture of the palatine tonsils.

    PubMed

    Plzak, Jan; Macokova, Pavla; Zabrodsky, Michal; Kastner, Jan; Lastuvka, Petr; Astl, Jaromir

    2014-01-01

    Radiofrequency surgery is a widely used modern technique for submucosal volume reduction of the tonsils. So far there is very limited information on morphologic changes in the human tonsils after radiofrequency surgery. We performed histopathological study of tonsillectomy specimens after previous bipolar radiofrequency induced thermotherapy (RFITT). A total of 83 patients underwent bipolar RFITT for hypertrophy of palatine tonsils. Tonsil volume reduction was measured by 3D ultrasonography. Five patients subsequently underwent tonsillectomy. Profound histopathological examination was performed to determine the effect of RFITT on tonsillar architecture. All tonsillectomy specimens showed the intact epithelium, intact germinal centers, normal vascularization, and no evidence of increased fibrosis. No microscopic morphological changes in tonsillectomy specimens after bipolar RFITT were observed. RFITT is an effective submucosal volume reduction procedure for treatment of hypertrophic palatine tonsils with no destructive effect on microscopic tonsillar architecture and hence most probably no functional adverse effect.

  15. Radiofrequency amplifier based on a dc superconducting quantum interference device

    DOEpatents

    Hilbert, Claude; Martinis, John M.; Clarke, John

    1986-01-01

    A low noise radiofrequency amplifier (10), using a dc SQUID (superconducting quantum interference device) as the input amplifying element. The dc SQUID (11) and an input coil (12) are maintained at superconductivity temperatures in a superconducting shield (13), with the input coil (12) inductively coupled to the superconducting ring (17) of the dc SQUID (11). A radiofrequency signal from outside the shield (13) is applied to the input coil (12), and an amplified radiofrequency signal is developed across the dc SQUID ring (17) and transmitted to exteriorly of the shield (13). A power gain of 19.5.+-.0.5 dB has been achieved with a noise temperature of 1.0.+-.0.4 K. at a frequency of 100 MHz.

  16. Radiofrequency amplifier based on a dc superconducting quantum interference device

    DOEpatents

    Hilbert, C.; Martinis, J.M.; Clarke, J.

    1984-04-27

    A low noise radiofrequency amplifer, using a dc SQUID (superconducting quantum interference device) as the input amplifying element. The dc SQUID and an input coil are maintained at superconductivity temperatures in a superconducting shield, with the input coil inductively coupled to the superconducting ring of the dc SQUID. A radiofrequency signal from outside the shield is applied to the input coil, and an amplified radiofrequency signal is developed across the dc SQUID ring and transmitted to exteriorly of the shield. A power gain of 19.5 +- 0.5 dB has been achieved with a noise temperature of 1.0 +- 0.4 K at a frequency of 100 MHz.

  17. Laparoscopic radiofrequency ablation of neuroendocrine liver metastases.

    PubMed

    Berber, Eren; Flesher, Nora; Siperstein, Allan E

    2002-08-01

    We previously reported on the safety and efficacy of laparoscopic radiofrequency thermal ablation (RFA) for treating hepatic neuroendocrine metastases. The aim of this study is to report our 5-year RFA experience in the treatment of these challenging group of patients. Of the 222 patients with 803 liver primary and secondary tumors undergoing laparoscopic RFA between January 1996 and August 2001, a total of 34 patients with 234 tumors had neuroendocrine liver metastases. There were 25 men and 9 women with a mean +/- SEM age of 52 +/- 2 years who underwent 42 ablations. Primary tumor types included carcinoid tumor in 18 patients, medullary thyroid cancer in 7, secreting islet cell tumor in 5, and nonsecreting islet cell tumor in 4. There was no mortality, and the morbidity was 5%. The mean hospital stay was 1.1 days. Symptoms were ameliorated in 95%, with significant or complete symptom control in 80% of the patients for a mean of 10+ months (range 6-24 months). All patients were followed for a mean +/- SEM of 1.6 +/- 0.2 years (range 1.0-5.4 years). During this period new liver lesions developed in 28% of patients, new extrahepatic disease in 25%, and local liver recurrence in 13%; existing liver lesions progressed in 13%. Overall 41% of patients showed no progression of their cancer. Nine patients (27%) died. Mean +/- SEM survivals after diagnosis of primary disease, detection of liver metastases, and performance of RFA were 5.5 +/- 0.8 years, 3.0 +/- 0.3 years, and 1.6 +/- 0.2 years, respectively. Sixty-five percent of the patients demonstrated a partial or significant decrease in their tumor markers during follow-up. In conclusion, RFA provides excellent local tumor control with overnight hospitalization and low morbidity in the treatment of liver metastases from neuroendocrine tumors. It is a useful modality in the management of these challenging group of patients.

  18. Photoacoustic characterization of radiofrequency ablation lesions

    NASA Astrophysics Data System (ADS)

    Bouchard, Richard; Dana, Nicholas; Di Biase, Luigi; Natale, Andrea; Emelianov, Stanislav

    2012-02-01

    Radiofrequency ablation (RFA) procedures are used to destroy abnormal electrical pathways in the heart that can cause cardiac arrhythmias. Current methods relying on fluoroscopy, echocardiography and electrical conduction mapping are unable to accurately assess ablation lesion size. In an effort to better visualize RFA lesions, photoacoustic (PA) and ultrasonic (US) imaging were utilized to obtain co-registered images of ablated porcine cardiac tissue. The left ventricular free wall of fresh (i.e., never frozen) porcine hearts was harvested within 24 hours of the animals' sacrifice. A THERMOCOOLR Ablation System (Biosense Webster, Inc.) operating at 40 W for 30-60 s was used to induce lesions through the endocardial and epicardial walls of the cardiac samples. Following lesion creation, the ablated tissue samples were placed in 25 °C saline to allow for multi-wavelength PA imaging. Samples were imaged with a VevoR 2100 ultrasound system (VisualSonics, Inc.) using a modified 20-MHz array that could provide laser irradiation to the sample from a pulsed tunable laser (Newport Corp.) to allow for co-registered photoacoustic-ultrasound (PAUS) imaging. PA imaging was conducted from 750-1064 nm, with a surface fluence of approximately 15 mJ/cm2 maintained during imaging. In this preliminary study with PA imaging, the ablated region could be well visualized on the surface of the sample, with contrasts of 6-10 dB achieved at 750 nm. Although imaging penetration depth is a concern, PA imaging shows promise in being able to reliably visualize RF ablation lesions.

  19. Radiofrequency ablation of hepatocellular carcinomas: A new spectrum of anesthetic experience at a tertiary care hospital in Pakistan

    PubMed Central

    Shamim, Faisal; Asghar, Ali; Tauheed, Saman; Yahya, Muhammad

    2017-01-01

    Background: Radiofrequency ablation (RFA) is a minimally invasive technique of tumor destruction for patients with hepatic cancer who are not candidates for conventional therapy. The therapy required general anesthesia (GA) or sedation to ensure patient safety and comfort. The study is aimed to report and evaluate factors that influenced the periprocedural anesthetic management, drugs used, and complications during and immediately after RFA procedure for hepatocellular carcinoma. Methods: For this retrospective study, we included 46 patients who underwent percutaneous RFA under GA or conscious sedation from January 2010 to June 2013 in Aga Khan University Hospital, Pakistan. The patients' characteristics, hepatic illness severity (Child-Pugh classification), anesthetic techniques, drugs, and complications of procedure were collected on a predesigned approved form. The data were assessed and summarized using descriptive statistics. Results: The majority of patients were female (57%) and mostly classified as American Society of Anesthesiologist III (65.2%). The preoperative hepatic illness severity in most patients was Child-Pugh Class A (76.10%). Thirty-eight patients (69.09%) had only single lesion and majority number of lesions were <3 cm (65.45). GA was the main anesthetic technique (87%) with laryngeal mask airway as an airway adjunct predominantly (70%). The mainly used anesthetic agents for hypnosis and analgesia were propofol and fentanyl, respectively. Pain was the only significant complaint in postoperative period but only in nine (19%) patients and mild in nature. Conclusions: Percutaneous RFA is a safe treatment of hepatocellular cancer. The procedure required good anesthetic support in the form of sedation-analgesia or complete GA that ensures maximum patient comfort and technical success of the procedure. PMID:28217048

  20. Feasibility of radiofrequency ablation as an alternative to surgical intervention in patients with huge multiloculated pyogenic liver abscesses

    PubMed Central

    Ke, Shan; Ding, Xue-Mei; Gao, Jun; Wang, Shao-Hong; Kong, Jian; Xu, Li; Sun, Wen-Bing

    2016-01-01

    Abstract This retrospective cohort study investigated the feasibility of radiofrequency (RF) ablation as an alternative to surgical intervention in patients with huge multiloculated pyogenic liver abscesses (PLAs). From August 2010 to April 2016, 83 patients with PLA were admitted to Beijing Chao-Yang Hospital, China. Four of these patients had huge multiloculated PLAs and underwent RF ablation plus antibiotics. The inclusion criteria for RF ablation were as follows: multiloculated PLA confirmed by computed tomography (CT) or magnetic resonance imaging (MRI), widest diameter of the PLA ≥5 cm, failure to respond to or not suitable to treatment with percutaneous drainage (PD), and patient refusal of surgery. The safety and effectiveness of RF ablation were initially assessed. All patients were commenced on antibiotics on admission to our hospital. CT-guided percutaneous catheter drainage was attempted in one patient but was unsuccessful. The main organism isolated from cultures of these patients’ blood or abscess samples was Klebsiella pneumoniae (3/4). RF ablation was performed as soon as eligibility according to the above criteria was established. RF ablation was technically successful in all 4 study patients, all PLAs being completely eradicated. The median duration of fever after RF ablation was 4.5 days. No abscesses recurred; thus, this strategy for managing PLA was 100% successful (4/4). No procedure-related deaths or major complications occurred. One patient had an asymptomatic right pleural effusion that resolved with conservative treatment including albumin infusion and diuretics. Our preliminary data indicate that RF ablation is a safe, feasible, and effective treatment for huge multiloculated PLAs. It should be considered as an alternative treatment for patients who fail to respond to or not suitable for PD plus antibiotics and refuse surgical intervention. PMID:27930527

  1. Effect of Mobile Phone Radiofrequency Electromagnetic Fields on.

    PubMed

    Umar, Z U; Abubakar, M B; Ige, J; Igbokwe, U V; Mojiminiyi, F B O; Isezuo, S A

    2014-12-29

    Since cell phones emit radiofrequency electromagnetic fields (EMFs), this study tested the hypothesis that cell phones placed near the heart may interfere with the electrical rhythm of the heart or affect the blood pressure. Following informed consent, eighteen randomly selected apparently healthy male volunteers aged 21.44 ± 0.53 years had their blood pressure, pulse rates and ECG measured before and after acute exposure to a cell phone. The ECG parameters obtained were: heart rate (HR), QRS complex duration (QRS), PR interval (PR) and Corrected QT interval (QTc). Results are presented as mean ± SEM. Statistical analyses were done using two-tailed paired t test for blood pressure and pulse rate data and one way ANOVA with a post hoc Tukey test for the ECG data. P<0.05 was considered statistically significant. The blood pressure and pulse rates before and after exposure to the cell phone showed no significant difference. The ECG parameters (HR: beats/min, QRS:ms, PR:ms and QTc respectively) did not differ before (66.33 ± 2.50, 91.78 ± 1.36, 151.67 ± 5.39 and 395.44 ± 4.96), during (66.33 ± 2.40, 91.11 ± 1.61, 153.67 ± 5.06 and 394.33 ± 4.05) and after calls (67.22 ± 2.77, 91.11 ± 1.67, 157.44 ± 4.46 and 396.56 ± 4.93) compared to baseline (67.17 ± 2.19, 94.33 ± 1.57, 150.56 ± 4.93 and 399.56 ± 3.88). These results suggest that acute exposure to EMFs from cell phones placed near the heart may not interfere with the electrical activity of the heart or blood pressure in healthy individuals.

  2. Lung Tumor Radiofrequency Ablation: Where Do We Stand?

    SciTech Connect

    Baere, Thierry de

    2011-04-15

    Today, radiofrequency ablation (RFA) of primary and metastatic lung tumor is increasingly used. Because RFA is most often used with curative intent, preablation workup must be a preoperative workup. General anesthesia provides higher feasibility than conscious sedation. The electrode positioning must be performed under computed tomography for sake of accuracy. The delivery of RFA must be adapted to tumor location, with different impedances used when treating tumors with or without pleural contact. The estimated rate of incomplete local treatment at 18 months was 7% (95% confidence interval, 3-14) per tumor, with incomplete treatment depicted at 4 months (n = 1), 6 months (n = 2), 9 months (n = 2), and 12 months (n = 2). Overall survival and lung disease-free survival at 18 months were, respectively, 71 and 34%. Size is a key point for tumor selection because large size is predictive of incomplete local treatment and poor survival. The ratio of ablation volume relative to tumor volume is predictive of complete ablation. Follow-up computed tomography that relies on the size of the ablation zone demonstrates the presence of incomplete ablation. Positron emission tomography might be an interesting option. Chest tube placement for pneumothorax is reported in 8 to 12%. Alveolar hemorrhage and postprocedure hemoptysis occurred in approximately 10% of procedures and rarely required specific treatment. Death was mostly related to single-lung patients and hilar tumors. No modification of forced expiratory volume in the first second between pre- and post-RFA at 2 months was found. RFA in the lung provides a high local efficacy rate. The use of RFA as a palliative tool in combination with chemotherapy remains to be explored.

  3. Preoperative radiofrequency ablation in painful osteolytic long bone metastases.

    PubMed

    Di Francesco, Alexander; Flamini, Stefano; Zugaro, Luigi; Zoccali, Carmine

    2012-08-01

    This study aimed to determine whether Radiofrequency Ablation (RFA) followed by prophylactic internal fixation produces better palliation in terms of pain and reduces the need for blood transfusion more than radiotherapy and surgical stabilization (RT-SS). Patients with solitary long bone metastases and a pain score of 5 or more on the VAS scale were selected. Fifteen patients were treated with RFA and surgical stabilization (RFA-SS) and were compared with a matched group (15 subjects) treated by radiotherapy and surgical stabilization (RT-SS). A complete response in terms of pain relief at 12 weeks was documented in 20% (3/15) and 533% (8/15) of the subjects treated by RT-SS or RFA-SS, respectively (p = 0.027). The overall response rate at 12 weeks was 93.3% (14 patients) in the group treated by RFA-SS and 59.9% (9 patients) in the group treated by RT-SS (p = 0.048). Although recurrent pain was documented more frequently after RT-SS (26.6%) than after RFA-SS (6.7%) the difference did not reach statistical significance. The morbidity related to RT-SS did not significantly differ when the treatment was associated with RFA. We observed a reduction in blood transfusion, as 3 patients in the RT-SS group required a blood transfusion, versus none in the RFA-SS group. Our results suggest that RFA-SS is safe and is more effective than RT-SS; furthermore, RFA may become an option for patients with metastases of the long bones to prevent tumour dissemination and reduce intraoperative blood loss. The findings described here should serve as a framework around which to design future clinical trials.

  4. ECG changes in factory workers exposed to 27.2  MHz radiofrequency radiation.

    PubMed

    Chen, Qingsong; Xu, Guoyong; Lang, Li; Yang, Aichu; Li, Shilin; Yang, Liwen; Li, Chaolin; Huang, Hanlin; Li, Tao

    2013-05-01

    To research the effect of 27.2 MHz radiofrequency radiation on electrocardiograms (ECG), 225 female workers operating radiofrequency machines at a shoe factory were chosen as the exposure group and 100 female workers without exposure from the same factory were selected as the control group. The 6 min electric field strength that the female workers were exposed to was 64.0 ± 25.2 V/m (mean ± SD), which exceeded 61 V/m, the International Commission on Non-Ionizing Radiation Protection reference root mean square levels for occupational exposure. A statistical difference was observed between the exposed group and the control group in terms of the rate of sinus bradycardia (χ(2)  = 11.48, P = 0.003). When several known risk factors for cardiovascular disease were considered, including smoking, age, alcohol ingestion habit, and so on, the exposure duration was not an effective factor for ECG changes, sinus arrhythmia, or sinus bradycardia according to α = 0.05, while P = 0.052 for sinus arrhythmia was very close to 0.05. We did not find any statistical difference in heart rate, duration of the QRS wave (ventricular depolarization), or corrected QT intervals (between the start of the Q wave and end of the T wave) between the exposed and control groups. Occupational exposure to radiofrequency radiation was not found to be a cause of ECG changes after consideration of the confounding factors.

  5. Histopomorphic evaluation of radiofrequency mediated débridement chondroplasty.

    PubMed

    Ganguly, Kumkum; McRury, Ian D; Goodwin, Peter M; Morgan, Roy E; Augé Ii, Wayne K

    2010-06-29

    The use of radiofrequency devices has become widespread for surgical ablation procedures. When ablation devices have been deployed in treatment settings requiring tissue preservation like débridement chondroplasty, adoption has been limited due to the collateral damage caused by these devices in healthy tissue surrounding the treatment site. Ex vivo radiofrequency mediated débridement chondroplasty was performed on osteochondral specimens demonstrating surface fibrillation obtained from patients undergoing knee total joint replacement. Three radiofrequency systems designed to perform débridement chondroplasty were tested each demonstrating different energy delivery methods: monopolar ablation, bipolar ablation, and non-ablation energy. Treatment outcomes were compared with control specimens as to clinical endpoint and histopomorphic characteristics. Fibrillated cartilage was removed in all specimens; however, the residual tissue remaining at the treatment site displayed significantly different characteristics attributable to radiofrequency energy delivery method. Systems that delivered ablation-based energies caused tissue necrosis and collateral damage at the treatment site including corruption of cartilage Superficial and Transitional Zones; whereas, the non-ablation system created a smooth articular surface with Superficial Zone maintenance and without chondrocyte death or tissue necrosis. The mechanism of radiofrequency energy deposition upon tissues is particularly important in treatment settings requiring tissue preservation. Ablation-based device systems can cause a worsened state of articular cartilage from that of pre-treatment. Non-ablation energy can be successful in modifying/preconditioning tissue during débridement chondroplasty without causing collateral damage. Utilizing a non-ablation radiofrequency system provides the ability to perform successful débridement chondroplasty without causing additional articular cartilage tissue damage and may

  6. Imaging Techniques in Percutaneous Cardiac Structural Interventions: Atrial Septal Defect Closure and Left Atrial Appendage Occlusion.

    PubMed

    Rodríguez Fernández, Antonio; Bethencourt González, Armando

    2016-08-01

    Because of advances in cardiac structural interventional procedures, imaging techniques are playing an increasingly important role. Imaging studies show sufficient anatomic detail of the heart structure to achieve an excellent outcome in interventional procedures. Up to 98% of atrial septal defects at the ostium secundum can be closed successfully with a percutaneous procedure. Candidates for this type of procedure can be identified through a systematic assessment of atrial septum anatomy, locating and measuring the size and shape of all defects, their rims, and the degree and direction of shunting. Three dimensional echocardiography has significantly improved anatomic assessments and the end result itself. In the future, when combined with other imaging techniques such as cardiac computed tomography and fluoroscopy, 3-dimensional echocardiography will be particularly useful for procedure guidance. Percutaneous closure of the left atrial appendage offers an alternative for treating patients with atrial fibrillation and contraindication for oral anticoagulants. In the future, the clinical focus may well turn to stroke prevention in selected patients. Percutaneous closure is effective and safe; device implantation is successful in 94% to 99% of procedures. However, the procedure requires an experienced cardiac structural interventional team. At present, 3-dimensional echocardiography is the most appropriate imaging technique to assess anatomy suitability, select device type and size, guide the procedure alongside fluoroscopy, and to follow-up the patient afterwards.

  7. [Image-guided bone consolidation in oncology: Cementoplasty and percutaneous screw fixation].

    PubMed

    Buy, Xavier; Cazzato, Roberto Luigi; Catena, Vittorio; Roubaud, Guilhem; Kind, Michele; Palussiere, Jean

    2017-03-17

    Bone metastases are a common finding in oncology. They often induce pain but also fractures which impair quality of life, especially when involving weight-bearing bones. Percutaneous image-guided consolidation techniques play a major role for the management of bone metastases. Cementoplasty aims to stabilize bone and control pain by injecting acrylic cement into a weakened bone. This minimally invasive technique has proven its efficacy for bones submitted to compression forces: vertebra, acetabular roof, and condyles. However, long bone diaphysis should be treated with caution due to lower resistance of the cement subject to torsional forces. The recent improvements of navigation systems allow percutaneous image-guided screw fixation without requiring open surgery. This fast-track procedure avoids postponing introduction of systemic therapies. If needed, cementoplasty can be combined with screw insertion to ensure better anchoring in major osteolysis. Interventional radiology bone consolidation techniques increase the therapeutic field in oncology. A multidisciplinary approach remains mandatory to select the best indications.

  8. Gastrostomy with peritoneal collar versus percutaneous endoscopic gastrostomy

    PubMed Central

    Tudor, C; Branescu, C; Savlovschi, C; El-Khatib, A; Pantu, H; Nica, A; Dascalu, AM; Masoumeh, B; Tudor, AS; Oprescu, SM; Serban, D

    2016-01-01

    Aim. The present study aimed to perform a medico-surgical comparative analysis of the 2 most widely used techniques: gastrostomy with peritoneal collar versus percutaneous endoscopic gastrostomy, based on the vast clinical experience in an Upper Digestive Surgery Clinic. Materials and method. A retrospective study was carried out between January 2010 and January 2015 on the patients admitted for a surgical solution for feeding. The indications, preoperative preparation, surgical techniques, and postoperative outcomes were analyzed. Results. Out of the 94 cases admitted for a surgical solution for feeding, 67 underwent gastrostomy with peritoneal collar (GPC) and in 27 cases percutaneous endoscopic gastrostomy (PEG) was performed. The indications for GPC were benign or malign causes of dysphagia, the most frequent being malign tumors of tongue, pharynx and larynx (47.76%), advanced inoperable esophageal or eso-cardiac cancers (26,86%), post-caustic esophageal stenosis (10.44%). PEG was performed in patients with functional difficulties of swallowing: sequelae of cerebral vascular accidents (44.44%), low Glasgow Coma Scale Score (29.62%) of different etiologies, Parkinson disease (18.51%) advanced dementia (7.4%), early nasopharyngeal cancer (2 cases). The intraoperatory and postoperatory complications were few and of minor importance in both techniques, but PEG allowed an immediate retake of alimentation (vs. at least 48 hours wait in GPC), with less gastric stasis, biliary reflux and aspiration related respiratory problems. Conclusions. Both techniques are easy and safe to perform, but an appropriate selection is required according to the cause of the swallowing difficulty. In cases with permeable digestive tube, PEG may be an excellent minimally invasive solution, but the costs and availability of the PEG kit and prehydrolyzed nutritive solution, as well as the co-existence of an upper digestive endoscopy service were limitations that had to be taken into account

  9. [NMR radiofrequency microcoil design: usefulness of electromagnetic simulation].

    PubMed

    Armenean, Mircea; Briguet, André; Saint-Jalmes, Hervé

    2002-04-01

    The extraction of the Nuclear Magnetic Resonance (NMR) spectra of samples having smaller and smaller volumes is a real challenge. Either these reductions of volume are dictated by the difficulties of production of sufficiently large samples or by necessities of miniaturisation of the analysing system, in both cases a careful design of the radiofrequency coil, ensuring an optimum reception of the NMR signal, is required. We have also evaluated the usefulness of electromagnetic simulation software for the design and optimisation of these radio-frequency coils, which are more and more used in biology and health research projects.

  10. A review of percutaneous techniques for low back pain and neuralgia: current trends in epidural infiltrations, intervertebral disk and facet joint therapies

    PubMed Central

    Kelekis, Alexis

    2016-01-01

    Low back pain and neuralgia due to spinal pathology are very common symptoms debilitating numerous patients with peak prevalence at ages between 45 and 60 years. Intervertebral discs and facet joints act as pain sources in the vast majority of the cases. Diagnosis is based on the combination of clinical examination and imaging studies. Therapeutic armamentarium for low back pain and neuralgia due to intervertebral discs and/or facet joints includes conservative therapy, injections, percutaneous therapeutic techniques and surgical options. Percutaneous, therapeutic techniques are imaging-guided, minimally invasive treatments which can be performed as outpatient procedures. In cases of facet joint syndrome, they include, apart from injections, neurolysis with radiofrequency/cryoablation, MR-guided high-intensity focused ultrasound and percutaneous fixation techniques. In case of discogenic pain, apart from infiltrations, therapeutic techniques can be classified in to two main categories: decompression (mechanical, thermal, chemical) techniques and biomaterials implantation/disc cell therapies. Strict sterility measures are a prerequisite and should include extensive local sterility and antibiotic prophylaxis. This article will report clinical and imaging findings for each pathology type and the association with treatment decision. In addition, we will describe in detail all possible treatment techniques for low back pain and neuralgia, and we will report recently published results of these techniques summarizing the data concerning safety and effectiveness as well as the level of evidence. Finally, we will try to provide a rational approach for the therapy of low back pain and neuralgia by means of minimally invasive imaging-guided percutaneous techniques. PMID:26463233

  11. A review of percutaneous techniques for low back pain and neuralgia: current trends in epidural infiltrations, intervertebral disk and facet joint therapies.

    PubMed

    Filippiadis, Dimitrios K; Kelekis, Alexis

    2016-01-01

    Low back pain and neuralgia due to spinal pathology are very common symptoms debilitating numerous patients with peak prevalence at ages between 45 and 60 years. Intervertebral discs and facet joints act as pain sources in the vast majority of the cases. Diagnosis is based on the combination of clinical examination and imaging studies. Therapeutic armamentarium for low back pain and neuralgia due to intervertebral discs and/or facet joints includes conservative therapy, injections, percutaneous therapeutic techniques and surgical options. Percutaneous, therapeutic techniques are imaging-guided, minimally invasive treatments which can be performed as outpatient procedures. In cases of facet joint syndrome, they include, apart from injections, neurolysis with radiofrequency/cryoablation, MR-guided high-intensity focused ultrasound and percutaneous fixation techniques. In case of discogenic pain, apart from infiltrations, therapeutic techniques can be classified in to two main categories: decompression (mechanical, thermal, chemical) techniques and biomaterials implantation/disc cell therapies. Strict sterility measures are a prerequisite and should include extensive local sterility and antibiotic prophylaxis. This article will report clinical and imaging findings for each pathology type and the association with treatment decision. In addition, we will describe in detail all possible treatment techniques for low back pain and neuralgia, and we will report recently published results of these techniques summarizing the data concerning safety and effectiveness as well as the level of evidence. Finally, we will try to provide a rational approach for the therapy of low back pain and neuralgia by means of minimally invasive imaging-guided percutaneous techniques.

  12. Review of endoscopic radiofrequency in biliopancreatic tumours with emphasis on clinical benefits, controversies and safety.

    PubMed

    Alvarez-Sánchez, María-Victoria; Napoléon, Bertrand

    2016-10-07

    Most pancreatic cancers and extrahepatic cholangiocarcinomas are unresectable at the time of diagnosis, and even in case of a resectable cancer, for elderly or patients with coexistent comorbidities, surgery is not an option. Current treatment alternatives in these scenarios are very limited. Biliary stenting with self-expanding metal stents (SEMS) is the mainstay palliative treatment of biliary obstruction due to unresectable pancreatic cancer or cholangiocarcinoma. Nevertheless, more than 50% of SEMS become occluded after 6 mo due to tumour over- and ingrowth, leading to hospital readmissions and reinterventions that significantly impair quality of life. Regimes of chemotherapy or chemoradiotherapy also provide minimal survival benefits. Therefore, novel therapies are eagerly awaited. Radiofrequency (RF) energy causes coagulative necrosis leading to local destruction of the accessed malignant tissue and has an established role in the treatment of malignancies in several solid organs, especially liver cancers. However, pancreatic and extrahepatic biliary cancers are not easily accessed by a percutaneous route, making the procedure dangerous. Over the past five years, the development of dedicated devices compatible with endoscopic instruments has offered a minimally invasive option for RF energy delivery in biliopancreatic cancers. Emerging experience with endoscopic RF ablation (RFA) in this setting has been reported in the literature, but little is known about its feasibility, efficacy and safety. A literature review makes it clear that RFA in biliopancreatic tumours is feasible with high rates of technical success and acceptable safety profile. Although available data suggest a benefit of survival with RFA, there is not enough evidence to draw a firm conclusion about its efficacy. For this reason, prospective randomized trials comparing RFA with standard palliative treatments with quality-of-life and survival endpoints are required. Anecdotal reports have also

  13. Radiofrequency Ablation of Osteoid Osteoma: Initial Experience with a New Monopolar Ablation Device

    SciTech Connect

    Mahnken, Andreas H. Bruners, Philipp; Delbrueck, Heide; Guenther, Rolf W.

    2011-06-15

    The purpose of this article is to report our initial experience with the 'off-label' use of a new monopolar radiofrequency (RF) probe for percutaneous ablation of osteoid osteomas. Seventeen patients (12 male and 5 female, mean age 24.8 [range 9-49]) with osteoid osteoma were treated by computed tomography (CT)-guided RF ablation (RFA). All procedures were performed with the patient under general aesthesia. After localization of the nidus, a 13G hollow drill was introduced into the nidus through a 7F introducer sheath. A monopolar 16.5G RF probe with a 9-mm active tip (Soloist; Boston Scientific, Natick, MA) was inserted through the introducer sheath and connected to the RF generator. Energy application was started at 2 W and subsequently increased every 2 min by 1 W to a maximum of 8 W. The procedure ended if impedance increased by 500 Ohm-Sign . Mean duration of energy deposition was 14.2 {+-} 3.3 min. Fourteen of 17 patients (82%) were free of symptoms at 29.9 {+-} 14.8 (range 4 to 47) months of follow-up. The primary and secondary success rates were 83% and 100%, respectively. In 3 patients, recurrence of pain at 6 (n = 1) and 15 (n = 2) months after the initial procedure was successfully treated by reablation. There were no complications. Monopolar RFA using the Soloist probe is effective and safe for the treatment of osteoid osteoma. It results in comparable success rates as other monopolar or bipolar RF systems in the treatment of osteoid osteoma.

  14. Ablation of large HCCs using a new saline-enhanced expandable radiofrequency device☆

    PubMed Central

    Tarantino, L.; Sordelli, I.; Nocera, V.; Piscopo, A.; Ripa, C.; Parmeggiani, D.; Sperlongano, P.

    2009-01-01

    Purpose Evaluation of a new device designed to achieve large volumes of necrosis in hepatocellular carcinoma (HCC) nodules by application of radiofrequency ablation (RFA). Materials and Methods 29 consecutive patients with 31 HCC nodules ≥3 cm in diameter (range 3–7.5 cm; mean diameter 5.5 cm) underwent ultrasound (US) guided percutaneous RFA using an expandable electrode with 7 active arrays and saline injection designed to create tissue ablation in areas of up to 7 cm (Starburst XLi-enhanced RFA device). Treatment was performed in general anesthesia (6 patients) or deep sedation (23 patients). Treatment efficacy was assessed by three-phase contrast-enhanced computed tomography (CT) and bimonthly US follow-up. Results One to three electrode insertions (mean number 1.6) were performed in each patient. CT showed complete necrosis in 23/31 HCC nodules (74%) in 22 patients. Follow-up of these 22 patients ranged from 2 to 15 months (mean time 8.3 months). In 6/22 patients (28%) intrahepatic recurrence occurred within 5–10 months (mean time 8.3 months). Major complications were post-ablation syndrome in 7/29 (24%), peritoneal effusion in 4/29 (14%), pleural effusion in 2/29 (7%) and transient obstructive jaundice in 1/29 (3.4%) patients. One patient died 6 months after treatment because of tumor progression. Conclusions In the treatment of large HCC nodules, Starburst XLi-enhanced is an effective and safe device. PMID:23396886

  15. Short-Term Results of Laparoscopic Radiofrequency Ablation Using a Multipolar System for Localized Hepatocellular Carcinoma

    PubMed Central

    Morimoto, Naoki; Isoda, Norio; Takaoka, Yoshinari; Hirosawa, Takuya; Watanabe, Shunji; Otake, Toshiya; Murayama, Kozue; Fujieda, Takeshi; Tsukui, Mamiko; Miyata, Natsumi; Ono, Kohei; Yamaguchi, Shota; Yamamoto, Hironori

    2017-01-01

    Background and Aim Multipolar radiofrequency ablation (RFA) is feasible for the treatment of hepatocellular carcinoma (HCC) for which a large ablative area is planned, and it imposes a light physical burden on patients. Multipolar RFA via the percutaneous approach is performed in the majority of cases, but the efficacy of multipolar RFA with a laparoscopic approach has rarely been studied. This study aimed to evaluate the efficacy and safety of multipolar laparoscopic RFA (LRA) for localized HCC over the short term. Methods From January 2014 to January 2016, 77 consecutive patients with 130 HCCs treated by multipolar LRA were assessed. One to three bipolar needle applicators were inserted under laparoscopic ultrasonography guidance, regardless of tumor location. We intended to achieve parallel insertions and no-touch ablation as much as possible. Results The median size of the main tumor was 22 mm (range, 10-42 mm). The median follow-up time was 13.6 months (range, 3.1-24.8 months). In all cases, a sufficient ablative area was obtained as planned, without thermal injury of adjacent organs. During the follow-up period, all patients were alive with no local tumor progression, while intrahepatic recurrence distant from the primary site occurred in 7 patients. The 2-year local tumor progression-free survival rate and overall cancer-free survival rate were 100 and 81.6%, respectively. There were no procedural major complications caused prolonging the hospitalization, and all patients were discharged without subjective symptoms 4-7 days after LRA. Conclusions Multipolar LRA was efficacious in the treatment of localized HCCs by safely achieving a good ablative area. PMID:28275580

  16. Radiofrequency Ablation of Large Renal Angiomyolipoma: Median-Term Follow-Up

    SciTech Connect

    Gregory, S. M. Anderson, C. J.; Patel, U.

    2013-06-15

    Purpose. To study the feasibility of percutaneous radiofrequency ablation (RFA) of large angiomyolipomas (AMLs) using saline-cooled electrodes. Materials and Methods. Institutional Review Board approval for the study was received. Four patients (all female, age range 33-67 years) with large AMLs (maximal axis 6.1-32.4 cm) not suitable for embolotherapy or surgery consented to a trial of RFA. Procedures were performed under computerized tomographic guidance using 14G saline-infused electrodes. Two ablations (diameter 4-7 cm) were undertaken in each patient. Variables studied were technical success, treatment safety, alteration of tumor consistency, tumor size, effect on renal function, and medium-term freedom from haemorrhage. Results. All four patients underwent successful RFA without any intraprocedural complications. There has been no haemorrhage, or new renal specific symptom, during a minimum 48-month period, and normal renal function has been normal. On follow-up radiological imaging, the tumors have become fattier with involution of the soft-tissue elements (soft tissue-to-total tumor ratio decreased mean [range] of 0.26 [0.14-0.48] to 0.17 [0.04-0.34] U; p = 0.04 [paired Student t test]). Further evidence of treatment effect was the development of a capsule around the ablation zone, but there was no change in overall tumor volume (mean [range] 1,120 [118-2,845] to 1150 [90-3,013] ml; p = 1 [paired Student t test]). Conclusion. RFA of large AMLs is technically feasible using saline-infused electrodes. The soft-tissue elements decreased in volume; the tumors become fattier; and there has been no renal haemorrhage during a 48-month period.

  17. Comparative thermal dosimetry of interstitial microwave and radiofrequency-LCF hyperthermia.

    PubMed

    Stauffer, P R; Sneed, P K; Suen, S A; Satoh, T; Matsumoto, K; Fike, J R; Phillips, T L

    1989-01-01

    Steady-state temperature distributions induced by commercial radiofrequency localized current field (RF-LCF) and microwave (MW) interstitial heating systems were compared in dog thigh muscle in vivo using repeated 15-min heating experiments in the same implant site. Control experiments consisting of up to nine successive, identical heat trials with either modality verified that induced temperature distributions could be duplicated reliably. For all comparative dosimetry experiments a square array of parallel heat sources and thermometry probes was inserted percutaneously through a 5 mm grid Plexiglas template to a depth of 7.0-8.0 cm. Metal trocar electrodes were left at the corners of square arrays for two or three successive RF-LCF heat trials. After the metal trocars were removed, two or three more heat trials were performed using dipole microwave antennas in Teflon catheters at the same four positions. The three-dimensional temperature distributions within the array boundaries were characterized by mapping up to 11 fibre optic temperature probes in 1 cm increments during the steady-state plateau of each trial. The distributions were analysed quantitatively in terms of the percentage of measured points which achieved at least 50 per cent of the maximum array temperature increase above baseline (delta Tmax). Results showed that the RF-LCF technique heated more uniformly with depth along the bare metal electrodes and more consistently within the array boundaries than the microwave dipole antennas. For all array spacings studied (1.0-3.5 cm), the RF electrodes heated approximately 10-20 per cent more of the array volume to greater than 50 per cent of delta Tmax.

  18. Lung Radiofrequency Ablation: In Vivo Experimental Study with Low-Perfusion-Rate Multitined Electrodes

    SciTech Connect

    Crocetti, Laura Lencioni, Riccardo; Bozzi, Elena; Sbrana, Alberto; Bartolozzi, Carlo

    2008-05-15

    The purpose of this study was to investigate the feasibility and safety of lung radiofrequency (RF) ablation by using low-perfusion-rate, expandable, multitined electrodes in an in vivo animal model. Ten New Zealand White rabbits underwent RF ablation using low-perfusion-rate, expandable, multitined electrodes (Starburst Talon; RITA Medical Systems, Mountain View, CA) and a 200-W RF generator. The electrode was positioned under fluoroscopy guidance and a single percutaneous RF ablation was performed. Saline perfusate was doped with nonionic iodinated contrast agent to render it visible on computed tomography (CT). The pump infused the saline doped with contrast agent into the lateral tines at a rate of 0.1ml/min. The planned ablation was of 3 min, with the hooks deployed to 2 cm at a target temperature of 105{sup o}C. An immediate posttreatment CT scan documented the distribution of the doped saline and the presence of immediate complications. The animals were monitored for delayed complications and sacrificed within 72 h (n = 4), 2 weeks (n = 3), or 4 weeks (n = 3). Assessment of ablation zone and adjacent structures was done at autopsy. Major complications consisted of pneumothorax requiring drainage (n = 2) and skin burn (n = 1). Immediately after the procedure the area of ablation was depicted at CT as a round, well-demarcated area, homogeneously opacified by iodinated contrast medium (mean size, 2.3 {+-} 0.8 cm). The presence of a sharply demarcated area of coagulation necrosis (mean size, 2.1 {+-} 0.4 cm) without severe damage to adjacent structures was confirmed at autopsy. In one case, euthanized at 4 weeks, in whom pneumothorax and pleural effusion were depicted, pleural fibrinous adhesions were demonstrated at autopsy. In conclusion, lung RF ablation performed in an in vivo animal model using low-perfusion-rate, expandable, multitined electrodes is feasible and safe. No severe damage to adjacent structures was demonstrated.

  19. Review of endoscopic radiofrequency in biliopancreatic tumours with emphasis on clinical benefits, controversies and safety

    PubMed Central

    Alvarez-Sánchez, María-Victoria; Napoléon, Bertrand

    2016-01-01

    Most pancreatic cancers and extrahepatic cholangiocarcinomas are unresectable at the time of diagnosis, and even in case of a resectable cancer, for elderly or patients with coexistent comorbidities, surgery is not an option. Current treatment alternatives in these scenarios are very limited. Biliary stenting with self-expanding metal stents (SEMS) is the mainstay palliative treatment of biliary obstruction due to unresectable pancreatic cancer or cholangiocarcinoma. Nevertheless, more than 50% of SEMS become occluded after 6 mo due to tumour over- and ingrowth, leading to hospital readmissions and reinterventions that significantly impair quality of life. Regimes of chemotherapy or chemoradiotherapy also provide minimal survival benefits. Therefore, novel therapies are eagerly awaited. Radiofrequency (RF) energy causes coagulative necrosis leading to local destruction of the accessed malignant tissue and has an established role in the treatment of malignancies in several solid organs, especially liver cancers. However, pancreatic and extrahepatic biliary cancers are not easily accessed by a percutaneous route, making the procedure dangerous. Over the past five years, the development of dedicated devices compatible with endoscopic instruments has offered a minimally invasive option for RF energy delivery in biliopancreatic cancers. Emerging experience with endoscopic RF ablation (RFA) in this setting has been reported in the literature, but little is known about its feasibility, efficacy and safety. A literature review makes it clear that RFA in biliopancreatic tumours is feasible with high rates of technical success and acceptable safety profile. Although available data suggest a benefit of survival with RFA, there is not enough evidence to draw a firm conclusion about its efficacy. For this reason, prospective randomized trials comparing RFA with standard palliative treatments with quality-of-life and survival endpoints are required. Anecdotal reports have also

  20. Laparoscopic vs computerized tomography-guided radiofrequency ablation for large hepatic hemangiomas abutting the diaphragm

    PubMed Central

    Gao, Jun; Kong, Jian; Ding, Xue-Mei; Ke, Shan; Niu, Hai-Gang; Xin, Zong-Hai; Ning, Chun-Min; Guo, Shi-Gang; Li, Xiao-Long; Zhang, Long; Dong, Yong-Hong; Sun, Wen-Bing

    2015-01-01

    AIM: To compare safety and therapeutic efficacy of laparoscopic radiofrequency (RF) ablation vs computed tomography (CT)-guided RF ablation for large hepatic hemangiomas abutting the diaphragm. METHODS: We retrospectively reviewed our sequential experience of treating 51 large hepatic hemangiomas abutting the diaphragm in 51 patients by CT-guided or laparoscopic RF ablation due to either the presence of symptoms and/or the enlargement of hemangioma. Altogether, 24 hemangiomas were ablated via a CT-guided percutaneous approach (CT-guided ablation group), and 27 hemangiomas were treated via a laparoscopic approach (laparoscopic ablation group). RESULTS: The mean diameter of the 51 hemangiomas was 9.6 ± 1.8 cm (range, 6.0-12.0 cm). There was no difference in the diameter of hemangiomas between the two groups (P > 0.05). RF ablation was performed successfully in all patients. There was no difference in ablation times between groups (P > 0.05). There were 23 thoracic complications in 17 patients: 15 (62.5%, 15/24) in the CT-guided ablation group and 2 (7.4%, 2/27) in the laparoscopic ablation group (P < 0.05). According to the Dindo-Clavien classification, two complications (pleural effusion and diaphragmatic rupture grade III) were major in two patients. All others were minor (grade I). Both major complications occurred in the CT-guided ablation group. The minor complications were treated successfully with conservative measures, and the two major complications underwent treatment by chest tube drainage and thoracoscopic surgery, respectively. Complete ablation was achieved in 91.7% (22/24) and 96.3% (26/27) in the CT-guided and the laparoscopic ablation groups, respectively (P > 0.05). CONCLUSION: Laparoscopic RF ablation therapy should be used as the first-line treatment option for large hepatic hemangiomas abutting the diaphragm. It avoids thermal injury to the diaphragm and reduces thoracic complications. PMID:26019459

  1. Microwave ablation for thyroid nodules: a new string to the bow for percutaneous treatments?

    PubMed Central

    Morelli, Francesco; Sacrini, Andrea; Pompili, Giovanni; Borelli, Anna; Panella, Silvia; Masu, Annamaria; De Pasquale, Loredana; Giacchero, Roberta

    2016-01-01

    Background Thyroid nodules are a fairly common finding in general population and, even if most of them are benign, a treatment can be however necessary. In the last years, non surgical minimally invasive techniques have been developed to treat this pathology, starting from percutaneous ethanol injection (PEI), to laser ablation (LA), radiofrequency ablation (RFA) and, most recently, microwave ablation (MWA). Methods We reviewed all medical literature searching in pubmed.gov the terms “microwave” & “thyroid”. We found three original studies concerning MWA treatment, for a total of 263 patients (mean age 51.0 years; range, 15–80 years; male to female ratio 2.55) and 522 nodules. Results A total of 522 nodules (338 solid, 22 cystic, 162 mixed) in 263 patients were treated. Studies have shown a mean reduction in volume of thyroid nodules ranging from 45.9% to 65%. No study reported a significant and definitive change in laboratory parameters, except for one case (Heck et al.). No studies have reported major complications after procedure. Conclusions MWA is a new, promising technique among the minimally invasive treatments of thyroid nodules. Actually, the larger diameter of MW antenna seems to be the major limiting factor in the use of this technique. More studies are necessary to evaluate feasibility, safety and efficacy of the procedure. PMID:28149799

  2. Percutaneous assist devices in acute myocardial infarction with cardiogenic shock: Review, meta-analysis

    PubMed Central

    Romeo, Francesco; Acconcia, Maria Cristina; Sergi, Domenico; Romeo, Alessia; Francioni, Simona; Chiarotti, Flavia; Caretta, Quintilio

    2016-01-01

    AIM: To assess the impact of percutaneous cardiac support in cardiogenic shock (CS) complicating acute myocardial infarction (AMI), treated with percutaneous coronary intervention. METHODS: We selected all of the studies published from January 1st, 1997 to May 15st, 2015 that compared the following percutaneous mechanical support in patients with CS due to AMI undergoing myocardial revascularization: (1) intra-aortic balloon pump (IABP) vs Medical therapy; (2) percutaneous left ventricular assist devices (PLVADs) vs IABP; (3) complete extracorporeal life support with extracorporeal membrane oxygenation (ECMO) plus IABP vs IABP alone; and (4) ECMO plus IABP vs ECMO alone, in patients with AMI and CS undergoing myocardial revascularization. We evaluated the impact of the support devices on primary and secondary endpoints. Primary endpoint was the inhospital mortality due to any cause during the same hospital stay and secondary endpoint late mortality at 6-12 mo of follow-up. RESULTS: One thousand two hundred and seventy-two studies met the initial screening criteria. After detailed review, only 30 were selected. There were 6 eligible randomized controlled trials and 24 eligible observational studies totaling 15799 patients. We found that the inhospital mortality was: (1) significantly higher with IABP support vs medical therapy (RR = +15%, P = 0.0002); (2) was higher, although not significantly, with PLVADs compared to IABP (RR = +14%, P = 0.21); and (3) significantly lower in patients treated with ECMO plus IABP vs IABP (RR = -44%, P = 0.0008) or ECMO (RR = -20%, P = 0.006) alone. In addition, Trial Sequential Analysis showed that in the comparison of IABP vs medical therapy, the sample size was adequate to demonstrate a significant increase in risk due to IABP. CONCLUSION: Inhospital mortality was significantly higher with IABP vs medical therapy. PLVADs did not reduce early mortality. ECMO plus IABP significantly reduced inhospital mortality compared to IABP. PMID

  3. Evaluation of Chemical Warfare Agent Percutaneous Vapor Toxicity: Derivation of Toxicity Guidelines for Assessing Chemical Protective Ensembles.

    SciTech Connect

    Watson, A.P.

    2003-07-24

    Percutaneous vapor toxicity guidelines are provided for assessment and selection of chemical protective ensembles (CPEs) to be used by civilian and military first responders operating in a chemical warfare agent vapor environment. The agents evaluated include the G-series and VX nerve agents, the vesicant sulfur mustard (agent HD) and, to a lesser extent, the vesicant Lewisite (agent L). The focus of this evaluation is percutaneous vapor permeation of CPEs and the resulting skin absorption, as inhalation and ocular exposures are assumed to be largely eliminated through use of SCBA and full-face protective masks. Selection of appropriately protective CPE designs and materials incorporates a variety of test parameters to ensure operability, practicality, and adequacy. One aspect of adequacy assessment should be based on systems tests, which focus on effective protection of the most vulnerable body regions (e.g., the groin area), as identified in this analysis. The toxicity range of agent-specific cumulative exposures (Cts) derived in this analysis can be used as decision guidelines for CPE acceptance, in conjunction with weighting consideration towards more susceptible body regions. This toxicity range is bounded by the percutaneous vapor estimated minimal effect (EME{sub pv}) Ct (as the lower end) and the 1% population threshold effect (ECt{sub 01}) estimate. Assumptions of exposure duration used in CPE certification should consider that each agent-specific percutaneous vapor cumulative exposure Ct for a given endpoint is a constant for exposure durations between 30 min and 2 hours.

  4. New Percutaneous Transluminal Coronary Angioscope

    NASA Astrophysics Data System (ADS)

    Arai, Tsunenori; Kikuchi, Makoto; Mizuno, Kyoichi; Arakawa, Ko; Shibuya, Toshio; Horiuchi, Kenji; Okamoto, Yasuyuki; Miyamoto, Akira; Isojima, Kazushige; Kurita, Akira

    1988-06-01

    A new thin coronary angioscope which has a inflatable balloon at its distal tip is described in this paper. This angioscope is formed into very thin flexible catheter, less than 4F(1.33mm) in sheath outer diameter at the catheter tip. The angioscope contains two penetrated lumina which utilize for either flushing blood or manipulating of a guiding wire. A selective intracoronary visualization in left anterior descending coronary artery (LAD) and circumuflex(CX) of dogs up to 15kg in their weight were carried out during up to 20s until occurring of ST segment change of the electro-cardiogram(ECG).

  5. Assessment of outdoor radiofrequency electromagnetic field exposure through hotspot localization using kriging-based sequential sampling

    SciTech Connect

    Aerts, Sam Deschrijver, Dirk; Verloock, Leen; Dhaene, Tom; Martens, Luc; Joseph, Wout

    2013-10-15

    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 km{sup 2}. 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 2 dB (factor 1.26 in electric-field strength), a correlation coefficient of 0.7, and a specificity of 0.96. -- Highlights: • We present an

  6. Fascicular ventricular tachycardia: experience with radiofrequency ablation.

    PubMed

    Magalhaes, Sónia; Gonçalves, Helena; Primo, João; Sá, Ana Paula; Silva, Paula; Rosas, Rui; Gama, Vasco

    2006-05-01

    at the tachycardia exit site failing, with no complications. If we include the success of a repeated case with three-dimensional mapping, the overall success rate was 80%. Ablation of fascicular tachycardia appears to be a good therapeutic option with a good success rate and without significant adverse events. The poor reproducibility as a consequence of contact inhibition during endocardial left ventricular mapping is the principal limiting factor. With the help of currently available mapping systems, we hope that this limitation will disappear, as it is now possible with some devices to acquire accurate information on suitable sites for subsequent radiofrequency application with little or no contact, facilitating the ablation procedure. Ablation at a site with simultaneous recording of DP and PP is considered by most authors to be more effective than that performed at the tachycardia exit site.

  7. Percutaneous Balloon Compression vs Percutaneous Retrogasserian Glycerol Rhizotomy for the Primary Treatment of Trigeminal Neuralgia

    PubMed Central

    Blomstedt, Patric; Bergenheim, A. Tommy

    2015-01-01

    BACKGROUND: Despite >30 years of clinical use, the literature is still sparse when it comes to comparisons between percutaneous balloon compression (PBC) and percutaneous retrogasserian glycerol rhizolysis (PRGR) as treatments for trigeminal neuralgia. OBJECTIVE: To perform a retrospective cohort comparison between PBC and PRGR with regard to therapeutic effect, side effects, and complications. METHODS: Medical records and follow-up data from 124 primary PRGRs performed from 1986 to 2000 and 82 primary PBCs performed from 2000 to 2013 were reviewed. All patients had undergone clinical sensory testing and assessment of sensory thresholds. Analyses were performed to compare duration of pain relief, frequency of sensory disturbances, and side effects. RESULTS: Median duration of pain relief was 21 months after PRGR and 20 months after PBC. Both methods carried a high risk of hypesthesia/hypalgesia (P < .001) that was partly reversed with time. Decreased corneal sensibility was common after PRGR (P < .001) but not after PBC. Dysesthesia was more common after PRGR (23%) compared after PBC (4%; P < .001). Other side effects were noted but uncommon. CONCLUSION: PBC and PRGR are both effective as primary surgical treatment of trigeminal neuralgia. Both carry a risk of postoperative hypesthesia, but in this series, the side effect profile favored PBC. Furthermore, PBC is technically less challenging, whereas PRGR requires fewer resources. Between these 2 techniques, we propose PBC as the primary surgical technique for percutaneous treatment of trigeminal neuralgia on the basis of its lower incidence of dysesthesia, corneal hypesthesia, and technical failures. ABBREVIATIONS: MS, multiple sclerosis PBC, percutaneous balloon compression PRGR, percutaneous retrogasserian glycerol rhizotomy TN, trigeminal neuralgia PMID:26465639

  8. Genetic damage in subjects exposed to radiofrequency radiation.

    PubMed

    Verschaeve, Luc

    2009-01-01

    Despite many research efforts and public debate there is still great concern about the possible adverse effects of radiofrequency (RF) radiation on human health. This is especially due to the enormous increase of wireless mobile telephones and other telecommunication devices throughout the world. The possible genetic effects of mobile phone radiation and other sources of radiofrequencies constitute one of the major points of concern. In the past several review papers were published on laboratory investigations that were devoted to in vitro and in vivo animal (cyto)genetic studies. However, it may be assumed that some of the most important observations are those obtained from studies with individuals that were exposed to relatively high levels of radiofrequency radiation, either as a result of their occupational activity or as frequent users of radiofrequency emitting tools. In this paper the cytogenetic biomonitoring studies of RF-exposed humans are reviewed. A majority of these studies do show that RF-exposed individuals have increased frequencies of genetic damage (e.g., chromosomal aberrations) in their lymphocytes or exfoliated buccal cells. However, most of the studies, if not all, have a number of shortcomings that actually prevents any firm conclusion. Radiation dosimetry was lacking in all papers, but some of the investigations were flawed by much more severe imperfections. Large well-coordinated multidisciplinary investigations are needed in order to reach any robust conclusion.

  9. 47 CFR 1.1310 - Radiofrequency radiation exposure limits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Criteria for Radiofrequency Electromagnetic Fields,” NCRP Report No. 86, Sections 17.4.1, 17.4.1.1, 17.4.2... Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz,”...

  10. The imprint of radiofrequency in the management of hepatocellular carcinoma

    PubMed Central

    Bramis, Ioannis; Triantopoulou, Charikleia; Madariaga, Juan; Dervenis, Christos

    2006-01-01

    Background. This article reviews the current results of radiofrequency application in the management of hepatocellular carcinoma (HCC) with reference to the comparison between the different surgical modalities. Method. An electronic search was performed for studies on the treatment of HCC. Results. Thermoablation by means of radiofrequency (RFA), microwave coagulation therapy (MCT) and laser-induced thermotherapy (LITT) provides tumor necrosis with a low complication rate. These methods are still not predictable and it is difficult to monitor the extent of necrosis in a real-time manner. Combined transarterial embolization and RF ablation is a promising strategy for large HCCs. Radiofrequency-assisted liver resection is unique and has become very popular recently because it permits parenchymal transection with minimal blood loss. Conclusion. Many alternative techniques have been applied recently for the management of HCC but their exact roles need to be defined by randomized studies. Advances in technology and refinements in technique may provide an effective and predictable way to ablate liver tumors using radiofrequency devices. PMID:18333136

  11. Extreme diffusion limited electropolishing of niobium radiofrequency cavities

    NASA Astrophysics Data System (ADS)

    Crawford, Anthony C.

    2017-03-01

    A deeply modulated, regular, continuous, oscillating current waveform is reliably and repeatably achieved during electropolishing of niobium single-cell elliptical radiofrequency cavities. Details of the technique and cavity test results are reported here. The method is applicable for cavity frequencies in the range 500 MHz to 3.9 GHz and can be extended to multicell structures.

  12. Radio-frequency energy in fusion power generation

    SciTech Connect

    Lawson, J.Q.; Becraft, W.R.; Hoffman, D.J.

    1983-01-01

    The history of radio-frequency (rf) energy in fusion experiments is reviewed, and the status of current efforts is described. Potential applications to tasks other than plasma heating are described, as are the research and development needs of rf energy technology.

  13. Longevity of radiofrequency identification device microchips in citrus trees

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Long-term identification of individual plants in the field is an important part of many types of botanical and horticultural research. In a previous report, we described methods for using implanted radiofrequency (RFID) microchips to tag citrus trees for field research. This report provides an upd...

  14. 21 CFR 886.4100 - Radiofrequency electrosurgical cautery apparatus.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radiofrequency electrosurgical cautery apparatus. 886.4100 Section 886.4100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN...-powered or battery-powered device intended for use during ocular surgery to coagulate tissue or...

  15. 21 CFR 886.4100 - Radiofrequency electrosurgical cautery apparatus.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radiofrequency electrosurgical cautery apparatus. 886.4100 Section 886.4100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN...-powered or battery-powered device intended for use during ocular surgery to coagulate tissue or...

  16. 21 CFR 886.4100 - Radiofrequency electrosurgical cautery apparatus.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radiofrequency electrosurgical cautery apparatus. 886.4100 Section 886.4100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN...-powered or battery-powered device intended for use during ocular surgery to coagulate tissue or...

  17. 77 FR 43535 - Grantee Codes for Certified Radiofrequency Equipment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-25

    ... COMMISSION 47 CFR Part 2 Grantee Codes for Certified Radiofrequency Equipment AGENCY: Federal Communications... grantee codes must consist of only three characters. This action will permit the Commission to issue longer grantee codes, thus greatly increasing the supply of available codes and ensuring that it...

  18. [Instrumental radiofrequency electromagnetic radiation dosimetry: general principals and modern methodology].

    PubMed

    Perov, S Iu; Kudriashov, Iu B; Rubtsova, N B

    2012-01-01

    The modern experimental radiofrequency electromagnetic field dosimetry approach has been considered. The main principles of specific absorbed rate measurement are analyzed for electromagnetic field biological effect assessment. The general methodology of specific absorbed rate automated dosimetry system applied to establish the compliance of radiation sources with the safety standard requirements (maximum permissible levels and base restrictions) is described.

  19. Cardiovascular risk in operators under radiofrequency electromagnetic radiation.

    PubMed

    Vangelova, Katia; Deyanov, Christo; Israel, Mishel

    2006-03-01

    The aim of the study was to assess the long-term effects of radiofrequency electromagnetic radiation (EMR) on the cardiovascular system. Two groups of exposed operators (49 broadcasting (BC) station and 61 TV station operators) and a control group of 110 radiorelay station operators, matched by sex and age, with similar job characteristics except for the radiofrequency EMR were studied. The EMR exposure was assessed and the time-weighted average (TWA) was calculated. The cardiovascular risk factors arterial pressure, lipid profile, body mass index, waist/hip ratio, smoking, and family history of cardiovascular disease were followed. The systolic and diastolic blood pressure (SBP and DBP), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were significantly higher in the two exposed groups. It was found that the radiofrequency EMR exposure was associated with greater chance of becoming hypertensive and dyslipidemic. The stepwise multiple regression equations showed that the SBP and TWA predicted the high TC and high LDL-C, while the TC, age and abdominal obesity were predictors for high SBP and DBP. In conclusion, our data show that the radiofrequency EMR contributes to adverse effects on the cardiovascular system.

  20. 47 CFR 1.1310 - Radiofrequency radiation exposure limits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... environmental impact of human exposure to radiofrequency (RF) radiation as specified in § 1.1307(b) within the... human exposure to RF radiation as specified in § 1.1307(b), except for portable devices as defined in... the environmental impact of human exposure to RF radiation as specified in § 1.1307(b). (4) Both...

  1. 47 CFR 1.1310 - Radiofrequency radiation exposure limits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... environmental impact of human exposure to radiofrequency (RF) radiation as specified in § 1.1307(b) within the... human exposure to RF radiation as specified in § 1.1307(b), except for portable devices as defined in... the environmental impact of human exposure to RF radiation as specified in § 1.1307(b). (4) Both...

  2. Extreme diffusion limited electropolishing of niobium radiofrequency cavities

    DOE PAGES

    Crawford, Anthony C.

    2017-01-04

    In this study, a deeply modulated, regular, continuous, oscillating current waveform is reliably and repeatably achieved during electropolishing of niobium single-cell elliptical radiofrequency cavities. Details of the technique and cavity test results are reported here. The method is applicable for cavity frequencies in the range 500 MHz to 3.9 GHz and can be extended to multicell structures.

  3. 78 FR 33633 - Human Exposure to Radiofrequency Electromagnetic Fields

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-04

    ... June 4, 2013 Part IV Federal Communications Commission 47 CFR Parts 1, 2, and 15, et al. Human Exposure..., and 95 Human Exposure to Radiofrequency Electromagnetic Fields AGENCY: Federal Communications... National Environmental Policy Act (NEPA) as they relate to the guidelines for human exposure to...

  4. Investigation of Radiofrequency Radiation Effects on Excitable Tissues.

    DTIC Science & Technology

    1981-07-31

    Barnes, "Microwave Effects on Isolated Neurons Vary with Field Orientation," (abstract) Bioelectro - magnetics 1:205, 1980. 88 25. W. F. Pickard, Y. H...Barsoum, and F. J. Rosenbaum, "Is the Characean Plasmalemma a Radio-Frequency Rectifier?" (abstract), Bioelectro - magnetics 1:216, 1980. 26. W. F

  5. [Thrombus visualisation during radiofrequency catheter ablation. A case report].

    PubMed

    Maciag, Aleksander; Szwed, Hanna; Pytkowski, Mariusz; Kraska, Alicja; Sterliński, Maciej

    2005-10-01

    We report two patients in whom thrombus formation during radiofrequency catheter ablation was detected by echocardiography. Resolution of thrombus after intravenous use of heparin was observed in both patients. Transesophageal and intracardiac echocardiography may be useful in management of this complication.

  6. Palliation of Painful Perineal Metastasis Treated with Radiofrequency Thermal Ablation

    SciTech Connect

    Thanos, L. Mylona, S.; Kalioras, V.; Pomoni, M.; Batakis, N.

    2005-04-15

    We report a case of painful perineal metastasis from urinary bladder carcinoma in a 73-years-old woman, treated with CT-guided radiofrequency ablation (RFA). The pain was immediately relieved and follow-up at 1 and 6 months showed total necrosis of the mass. One year later, the patient has no pain and her quality of life is improved.

  7. Arthroscopic gluteal muscle contracture release with radiofrequency energy.

    PubMed

    Liu, Yu-Jie; Wang, Yan; Xue, Jing; Lui, Pauline Po-Yee; Chan, Kai-Ming

    2009-03-01

    Gluteal muscle contracture is common after repeated intramuscular injections and sometimes is sufficiently debilitating to require open surgery. We asked whether arthroscopic release of gluteal muscle contracture using radiofrequency energy would decrease complications with clinically acceptable results. We retrospectively reviewed 108 patients with bilateral gluteal muscle contractures (57 males, 51 females; mean age, 23.7 years). We used inferior, anterosuperior, and posterosuperior portals. With the patient lying laterally, we developed and enlarged a potential space between the gluteal muscle group and the subcutaneous fat using blunt dissection. Under arthroscopic guidance through the inferior portal, we débrided and removed fatty tissue overlying the contractile band of the gluteal muscle group using a motorized shaver introduced through the superior portal. Radiofrequency then was introduced through the superior portal to gradually excise the contracted bands from superior to inferior. Finally, hemostasis was ensured using radiofrequency. Patients were followed a minimum of 7 months (mean, 17.4 months; range, 7-42 months). At last followup, the adduction and flexion ranges of the hip were 45.3 degrees +/- 8.7 degrees and 110.2 degrees +/- 11.9 degrees, compared with 10.4 degrees +/- 7.2 degrees and 44.8 degrees +/- 14.1 degrees before surgery. No hip abductor contracture recurred and no patient had residual hip pain or gluteal muscle wasting. We found gluteal muscle contracture could be released effectively with radiofrequency energy.

  8. Multi-functional liposomes showing radiofrequency-triggered release and magnetic resonance imaging for tumor multi-mechanism therapy

    NASA Astrophysics Data System (ADS)

    Du, Bin; Han, Shuping; Li, Hongyan; Zhao, Feifei; Su, Xiangjie; Cao, Xiaohui; Zhang, Zhenzhong

    2015-03-01

    Recently, nanoplatforms with multiple functions, such as tumor-targeting drug carriers, MRI, optical imaging, thermal therapy etc., have become popular in the field of cancer research. The present study reports a novel multi-functional liposome for cancer theranostics. A dual targeted drug delivery with radiofrequency-triggered drug release and imaging based on the magnetic field influence was used advantageously for tumor multi-mechanism therapy. In this system, the surface of fullerene (C60) was decorated with iron oxide nanoparticles, and PEGylation formed a hybrid nanosystem (C60-Fe3O4-PEG2000). Thermosensitive liposomes (dipalmitoylphosphatidylcholine, DPPC) with DSPE-PEG2000-folate wrapped up the hybrid nanosystem and docetaxel (DTX), which were designed to combine features of biological and physical (magnetic) drug targeting for fullerene radiofrequency-triggered drug release. The magnetic liposomes not only served as powerful tumor diagnostic magnetic resonance imaging (MRI) contrast agents, but also as powerful agents for photothermal ablation of tumors. Furthermore, a remarkable thermal therapy combined chemotherapy multi-functional liposome nanoplatform converted radiofrequency energy into thermal energy to release drugs from thermosensitive liposomes, which was also observed during both in vitro and in vivo treatment. The multi-functional liposomes also could selectively kill cancer cells in highly localized regions via their excellent active tumor targeting and magnetic targeted abilities.

  9. Sustained Growth of the Ex Vivo Ablation Zones' Critical Short Axis Using Gas-cooled Radiofrequency Applicators

    SciTech Connect

    Rempp, Hansjoerg; Scharpf, Marcus; Voigtlaender, Matthias; Schraml, Christina; Schmidt, Diethard; Fend, Falko; Claussen, Claus D.; Enderle, Markus D.; Pereira, Philippe L.; Clasen, Stephan

    2011-02-15

    Purpose: To evaluate the ablation zones created with a gas-cooled bipolar radiofrequency applicator performed on ex vivo bovine liver tissue. Materials and Methods: A total of 320 ablations with an internally gas-cooled bipolar radiofrequency applicator were performed on fresh ex vivo bovine liver tissue, varying the ablation time (5, 10, 15, and 20 min), power (20, 30, 40, and 50 W), and gas pressure of the CO{sub 2} used for cooling (585, 600, 615, 630, 645 psi), leading to a total of 80 different parameter combinations. Size and shape of the white coagulation zone were assessed. Results: The largest complete ablation zone was achieved after 20 min of implementing 50 W and 645 psi, resulting in a short axis of mean 46 {+-} 1 mm and a long axis of 56 {+-} 2 mm (mean {+-} standard deviation). Short-axis diameters increased between 5 and 20 min of ablation time at 585 psi (increase of the short axis was 45% at 30 W, 29% at 40 W, and 39% at 50 W). This increase was larger at 645 psi (113% at 30 W, 67% at 40 W, and 70% at 50 W). Macroscopic assessment and NADH (nicotinamide adenine dinucleotide) staining revealed incompletely ablated tissue along the needle track in 18 parameter combinations including low-power settings (20 and 30 W) and different cooling levels and ablation times. Conclusion: Gas-cooled radiofrequency applicators increase the short-axis diameter of coagulation in an ex vivo setting if appropriate parameters are selected.

  10. Orthopedic surgical analyzer for percutaneous vertebroplasty

    NASA Astrophysics Data System (ADS)

    Tack, Gye Rae; Choi, Hyung Guen; Lim, Do H.; Lee, Sung J.

    2001-05-01

    Since the spine is one of the most complex joint structures in the human body, its surgical treatment requires careful planning and high degree of precision to avoid any unwanted neurological compromises. In addition, comprehensive biomechanical analysis can be very helpful because the spine is subject to a variety of load. In case for the osteoporotic spine in which the structural integrity has been compromised, it brings out the double challenges for a surgeon both clinically and biomechanically. Thus, we have been developing an integrated medical image system that is capable of doing the both. This system is called orthopedic surgical analyzer and it combines the clinical results from image-guided examination and the biomechanical data from finite element analysis. In order to demonstrate its feasibility, this system was applied to percutaneous vertebroplasty. Percutaneous vertebroplasty is a surgical procedure that has been recently introduced for the treatment of compression fracture of the osteoporotic vertebrae. It involves puncturing vertebrae and filling with polymethylmethacrylate (PMMA). Recent studies have shown that the procedure could provide structural reinforcement for the osteoporotic vertebrae while being minimally invasive and safe with immediate pain relief. However, treatment failures due to excessive PMMA volume injection have been reported as one of complications. It is believed that control of PMMA volume is one of the most critical factors that can reduce the incidence of complications. Since the degree of the osteoporosis can influence the porosity of the cancellous bone in the vertebral body, the injection volume can be different from patient to patient. In this study, the optimal volume of PMMA injection for vertebroplasty was predicted based on the image analysis of a given patient. In addition, biomechanical effects due to the changes in PMMA volume and bone mineral density (BMD) level were investigated by constructing clinically

  11. Spondylodiscitis: a rare complication following percutaneous nephrostomy.

    PubMed

    Chiancone, Francesco; Fedelini, Maurizio; Meccariello, Clemente; Pucci, Luigi; Fabiano, Marco; Fedelini, Paolo

    2016-11-28

    Spondylodiscitis is an inflammation of the intervertebral disc and the adjacent vertebral bodies. The spondylodiscitis can not only be a complication of medical interventions such as an operation near spinal column but also urogenital and vascular interventions and intravenous catheter use. A 71-year-old man was admitted to our emergency department with fever and severe abdominal pain. Antibiotic therapy had been performed with intravenous administration of 2 g of ceftriaxone and the patient underwent the placement of a percutaneous nephrostomy according to Seldinger technique. After 1 week, the patient experienced a severe pain at the lumbar tract of the vertebral column associated with a moderate abdominal pain and septic fever. A magnetic resonance imaging (MRI) of the lumbar spine showed widespread impregnation of the upper portion of L3 and the lower portion of L2 compressing the spinal roots as well as the ileopsoas muscle such as a spondylodiscitis. Liquor culture showed an increase of liquor immunoglobulin G, total liquor protein and was positive for Extended-spectrum beta-lactamases (ESBL) - producing Escherichia coli. After the antibiotic therapy, the spondylodiscitis resolves without important sequelae. In the present case report, we describe a very rare complication of percutaneous nephrostomy tube placement, despite of the prophylactic antibiotic therapy according to the most recent guidelines. Predisposing factors to spondylodiscitis include the very young and elderly, the immunosuppressed, diabetic individuals and a general debilitating disease such as renal failure. This case suggests the importance of remembering spondylodiscitis when septic fever and back pain occurs following the placement of a percutaneous nephrostomy in a septic patient.

  12. Radiofrequency Ablation Versus Partial Nephrectomy in Treating Small Renal Tumors

    PubMed Central

    Yin, Xiaotao; Cui, Liang; Li, Fanglong; Qi, Siyong; Yin, Zhaoyang; Gao, Jiangping

    2015-01-01

    Abstract Radiofrequency ablation (RFA) has emerged as an alternative treatment to surgical partial nephrectomy (PN) in the treatment of small renal tumors (SRTs). But its safety and oncological efficacy are still controversial. We conducted this systematic review and meta-analysis to compare the peritoperative and oncological outcomes of RFA and PN in the treatment of SRTs. Pubmed, EMBASE, Cochrane CENTRAL, and Web of Science were searched to identify eligible studies that compared the RFA and PN in the treatment of SRTs. Twelve retrospective studies that compared RFA with PN in the treatment of SRTs met our selection criterion and were included in this meta-analysis. The pooled results indicated that the local recurrence rate (4.14% vs 4.10%, RR: 1.18, 95% CI: 0.68, 2.07, P = 0.550) and distant metastases rate (2.76% vs 1.89%, RR: 1.31, 95% CI: 0.70, 2.46, P = 0.686) were not significantly different between the RFA group and the PN group. In terms of perioperative outcomes, RFA was associated with shorter length of stay (LOS) (WMD: −2.02 days, 95% CI: −2.77, −1.27, P < 0.001), lower eGFR decline after treatment (WMD: −3.90, 95% CI: −6.660, −1.140, P = 0.006). However, the overall perioperative complication rate (7.5% vs 6.2%, RR:1.10, 95% CI: 0.64, 1.87, P = 0.740) and the major complication rate (3.7% vs 4.4%, RR: 0.83, 95% CI: 0.43, 1.60, P = 0.579) were both similar between RFA and PN groups. Compared with PN, RFA achieves an equal oncological outcome for SRTs with similar local recurrence rate and distant metastases rate. Additionally, RFA is associated with a similar perioperative complication rate, lower decline of eGFR, and shorter LOS. Therefore, RFA is an effective option in the treatment of SRTs for selected patients. PMID:26683944

  13. Arthroscopically assisted percutaneous fixation of Bennett fractures.

    PubMed

    Culp, Randall W; Johnson, Jeff W

    2010-01-01

    Arthroscopic-assisted reduction and fixation of Bennett-type fractures of the thumb metacarpal allow for the confirmation of reduction as well as the assessment of the degree of chondral damage. With use of a 1.9-mm arthroscope and a traction tower, direct visualization and reduction is possible. Traditional methods of fixation are used to secure the fracture fragment. Postoperative rehabilitation follows the usual protocol used in both open and percutaneous techniques. However, the potential to obtain and confirm a more accurate articular reduction may reduce the incidence of late arthritis of the thumb carpometacarpal articulation.

  14. Direct Percutaneous Embolization of Bleeding Stomal Varices

    SciTech Connect

    Naidu, Sailen G.; Castle, Erik P.; Kriegshauser, J. Scott; Huettl, Eric A.

    2010-02-15

    Stomal variceal bleeding can develop in patients with underlying cirrhosis and portal hypertension. Most patients are best treated with transjugular intrahepatic portosystemic shunt (TIPS) creation because this addresses the underlying problem of portal hypertension. However, some patients are not good candidates for TIPS creation because they have end-stage liver disease or encephalopathy. We describe such a patient who presented with recurrent bleeding stomal varices, which was successfully treated with percutaneous coil embolization. The patient had bleeding-free survival for 1 month before death from unrelated causes.

  15. Pneumomediastinum after percutaneous endoscopic gastrostomy tube placement.

    PubMed

    Yount, Kenan W; Mallory, Melissa A; Turza, Kristin C; Griffiths, Eric R; Lau, Christine L; Sawyer, Robert G

    2014-02-01

    The incidence of esophageal perforation or confounding mechanisms of pneumomediastinum specifically introduced by the addition of percutaneous endoscopic gastrostomy (PEG) tube insertion to esophagogastroduodenoscopy have not been described, and pneumomediastinum in the absence of esophageal perforation after PEG has not been reported. Typically, pneumomediastinum is an ominous finding, although benign causes exist. We present two cases of post-PEG pneumomediastinum not correlated with esophageal perforation on follow-up imaging. When pneumomediastinum is detected after PEG, appropriate studies should be undertaken to confirm its cause and to determine treatment plans. Further investigation may be warranted to ascertain the true incidence, causes, and clinical significance of post-PEG pneumomediastinum.

  16. Correction of Coagulopathy for Percutaneous Interventions

    PubMed Central

    Wiltrout, Charles; Kondo, Kimi L.

    2010-01-01

    Due to medical illness or pharmacotherapy, patients undergoing percutaneous interventions often have abnormal hemostasis. Its etiology may include alterations in the protein-based coagulation system, thrombocytopenia, deficient platelet function, or mixed deficits such as disseminated intravascular coagulation. In this article, the authors review the basic science of each of these etiologies, as well as their available methods of correction. They also review the evidence and guidelines regarding the assessment and treatment of coagulopathy in image-guided procedures. The periprocedural bleeding risk and the urgency of a given procedure guide the management of abnormal hemostasis in this patient population. PMID:22550375

  17. Percutaneous Cryoablation and Vertebroplasty: A Case Report

    SciTech Connect

    Masala, Salvatore; Roselli, Mario; Manenti, Guglielmo; Mammucari, Matteo; Bartolucci, Dario Alberto Simonetti, Giovanni

    2008-05-15

    A 70-year-old man with a painful vertebral metastasis was treated with combined percutaneous cryoablation and vertebroplasty therapy (CVT) in one session. The patient was suffering from diffuse visceral metastasized cholangiocarcinoma. After several weeks of back pain, magnetic resonance imaging documented a single L2 bone metastasis. In consultation with the oncologists, palliative combined CVT was administered with the aim of obtaining pain relief and bone stabilization. In our experience this combined treatment is safe and effective for immediate pain relief in painful bone metastases when other standard palliative treatments have failed.

  18. The peculiar ultrasonographic and elastographic features of thyroid nodules after treatment with laser or radiofrequency: similarities and differences.

    PubMed

    Andrioli, Massimiliano; Valcavi, Roberto

    2014-12-01

    The aim of percutaneous thermal ablation with laser (LA) or radiofrequency (RFA) is to reduce the volume of benign thyroid nodules. Little is known about ultrasonographic and elastographic appearances of thyroid lesions after treatment. For the first time, we report in detail the main ultrasonographic and elastographic characteristics of thermally ablated nodules and their underlying similarities and differences. Both thermal treatments usually produce a marked hypoechoic area of coagulative necrosis. LA-treated lesions usually become highly heterogeneous due to the presence of cavitations and charring; they then evolve into hyperechoic scars. In RFA-treated nodules, instead, the necrotic area is more homogeneous but presents more irregular margins compared to those observed in LA-treated lesions. Regardless of the thermal method used, vascularity is typically reduced in all treated nodules and stiffness, evaluated with qualitative elastography, increases. In conclusion, ultrasonographic and elastographic appearances of the thermally ablated thyroid lesions differ slightly according to the adopted procedure. Furthermore, they are peculiar, changeable over time, and potentially misleading.

  19. Unintended Thermal Injuries from Radiofrequency Ablation: Organ Protection with an Angioplasty Balloon Catheter in an Animal Model

    PubMed Central

    Knuttinen, Martha-Grace; Van Ha, Thuong G.; Reilly, Christopher; Montag, Anthony; Straus, Christopher

    2014-01-01

    Objectives: The aim of this study was to investigate a novel approach of using a balloon catheter as a protective device to separate liver from the diaphragm or nearby bowel during radiofrequency ablation (RFA) of hepatic dome tumors in an animal model. Materials and Methods: All experimental procedures were approved by animal Institutional Review Board. Using a 3 cm RF needle electrode, 70 hepatic ablation zones were created using ultrasound in 7 pigs. 50 lesions were created using balloon interposition between liver and diaphragm; 20 lesions were created using the balloon device interposed posteriorly between liver and bowel. Additional 21 control lesions were performed. Animals were sacrificed immediately; diaphragm and bowel were then visually inspected and sectioned. Diaphragmatic and bowel injury was then classified according to the depth of thickness. Results: Control lesions caused full thickness injury, either to diaphragm or bowel. During ablation of lesions with balloon interposition, there was significantly less diaphragmatic injury, P < 0.001 and less bowel injury, P < 0.01. Conclusion: Using balloon interposition as a protective device has advantages over previous saline infusion or CO2 insufflation, providing a safe way to expand percutaneous RFA of liver tumors located on the undersurface of the diaphragm. In addition, this method may be used in protection of other organs adjacent to areas being ablated. PMID:24678433

  20. Percutaneous absorption of chemicals: developing an understanding for the treatment of disease in frogs.

    PubMed

    Llewelyn, V K; Berger, L; Glass, B D

    2016-04-01

    The permeable nature of frog skin presents an alternative route for the delivery of therapeutic chemicals to treat disease in frogs. However, although therapeutic chemicals are often topically applied to the skin of frogs, their pharmacokinetics have rarely been reported. To provide evidence to guide both candidate drug and formulation selection, we highlight factors expected to influence percutaneous absorption through frog skin, including the anatomy and physiology of the skin and the physicochemical properties of applied therapeutic chemicals. Importantly, we also highlight the effects of the formulation on percutaneous absorption, especially the inclusion of potential penetration enhancers as excipients. Finally, we collate empirical data on the topical application of various therapeutic chemicals in postmetamorphic frogs and show that, in contrast to mammalian species, even large chemicals (i.e. >500 Da) and those with a wide range of log P values (-4 through +6) are likely to be absorbed percutaneously. Topical application in frogs thus promises a convenient and effective method for delivering systemic treatments of a diverse range of chemicals; however, further experimental quantification is required to ensure optimal outcomes.

  1. Totally Percutaneous Access Using Perclose Proglide for Endovascular Treatment of Aortic Diseases

    PubMed Central

    Saadi, Eduardo Keller; Saadi, Marina; Saadi, Rodrigo; Tagliari, Ana Paula; Mastella, Bernardo

    2017-01-01

    Objective To evaluate our experience following the introduction of a percutaneous program for endovascular treatment of aortic diseases using Perclose Proglide® assessing efficacy, complications and identification of potential risk factors that could predict failure or major access site complications. Methods A retrospective cohort study during a two-year period was performed. All the patients submitted to totally percutaneous endovascular repair (PEVAR) of aortic diseases and transcatheter aortic valve implantation since we started the total percutaneous approach with the preclosure technique from November 2013 to December 2015 were included in the study. The primary endpoint was major ipsilateral access complication, defined according to PEVAR trial. Results In a cohort of 123 patients, immediate technical success was obtained in 121 (98.37%) patients, with only two (0.82%) cases in 242 vascular access sites that required intervention immediately after the procedure. Pairwise comparisons revealed increased major access complication among patients with >50% common femoral artery (CFA) calcification vs. none (P=0.004) and > 50% CFA calcification vs. < 50% CFA calcification (P=0.002). Small artery diameter (<6.5 mm) also increased major access complication compared to bigger diameters (> 6.5 mm) (P=0.027). Conclusion The preclosure technique with two Perclose Proglide® for PEVAR is safe and effective. Complications occur more often in patients with unfavorable access site anatomy and the success rate can be improved with proper patient selection.

  2. Percutaneous Screw Fixation of Crescent Fracture-Dislocation of the Sacroiliac Joint.

    PubMed

    Shui, Xiaolong; Ying, Xiaozhou; Mao, Chuanwan; Feng, Yongzeng; Chen, Linwei; Kong, Jianzhong; Guo, Xiaoshan; Wang, Gang

    2015-11-01

    Crescent fracture-dislocation of the sacroiliac joint (CFDSIJ) is a type of lateral compression pelvic injury associated with instability. Open reduction and internal fixation is a traditional treatment of CFDSIJ. However, a minimally invasive method has never been reported. The purpose of this study was to assess the outcome of closed reduction and percutaneous fixation for different types of CFDSIJ and present their clinical outcome. The authors reviewed 117 patients diagnosed with CFDSIJ between July 2003 and July 2013. Closed reduction and percutaneous fixation was performed in 73 patients. Treatment selection was based on Day's fracture classification. For type I fractures, fixation perpendicular to the fracture line were performed. For type II fractures, crossed fixation was performed. For type III fractures, fixation was performed with iliosacral screws. Forty-four patients were treated by open reduction and plate fixation. Demographics, fracture pattern distribution, blood loss, incision lengths, revision surgeries, radiological results, and functional scores were compared. All 117 patients were followed for more than 6 months (mean, 14 months [range, 6-24 months]). Blood loss, extensive exposure, duration of posterior ring surgery, duration of hospital stay, and infection rates were lower in the closed group (P<.01). Patients in the closed group achieved better functional performance (P<.01). There were no significant differences in reduction quality (P=.32), revision surgery rates (P=.27), and iatrogenic neurologic injuries (P=.2) between the 2 groups. The authors' results indicate that closed reduction and percutaneous fixation is a safe and effective surgical method for CFDSIJ.

  3. Percutaneous endoscopic gastrostomy in children: a single center experience

    PubMed Central

    Koca, Tuğba; Sivrice, Ayşe Çiğdem; Dereci, Selim; Duman, Levent; Akçam, Mustafa

    2015-01-01

    Aim: The aim of this study was to evaluate the demographic data and complication rates in children who had undergone percutaneous endoscopic gastrostomy in a three-year period in our Division of Pediatric Gastroenterology and to interrogate parental satisfaction. Material and Methods: The demographic data, complications and follow-up findings of the patients who had undergone percutaneous endoscopic gastrostomy between March 2011 and March 2014 were examined retrospectively using medical files. Results: Forty seven percutaneous endoscopic gastrostomy and percutaneous endoscopic gastrostomy related procedures were performed in 34 children during a three-year period. The median age of the patients was 2.25 years (3 months-16 years, first and third quartiles=1.0–6.0) and the mean body weight was 13.07±8.6 kg (3 kg-47 kg). Before percutaneous endoscopic gastrostomy procedure, the mean weight z score was −2.26±1.2 (−5–0) and the mean height z score was −2.25±0.96 (−3.85–0.98). The follow-up mean height and weight Z scores at the 12th month after the percutaneous endoscopic gastrostomy procedure could be reached in 24 patients. A significant increase in the mean weight Z score from −2.41 to −1,07 (p=0.000) and in the mean height Z score from −2.29 to −1.99 (p=0.000) was found one year after percutaneous endoscopic gastrostomy catheter was placed in these 24 patients. Patients with neurological and metabolic diseases constituted the majority (64.7% and 26.5% respectively). Peritoneal leakage of food was detected in one patient and local stoma infections were detected in three patients after the procedure. During the follow up period, “Buried bumper syndrome” was observed in one patient. Following percutaneous endoscopic gastrostomy, the number of patients using anti-reflux medication increased from 16 (47.1%) to 18 (52.9%) (p=0.62). One patient with cerebral palsy who had aspiration pneumonia after percutaneous endoscopic gastrostomy insertion

  4. Bone Cement-Augmented Percutaneous Screw Fixation for Malignant Spinal Metastases: Is It Feasible?

    PubMed Central

    Kim, Pius; Kim, Seok Won

    2017-01-01

    Objective We evaluated the validity of bone cement-augmented percutaneous screw fixation for treating malignant spinal metastases. Methods Between 2011 and 2015, 14 patients (eight men and six women) who underwent bone cement-augmented percutaneous screw fixation for malignant spinal metastases were enrolled in this study. Their life expectancy was considered to be more than one month and less than one year, based on the revised Tokuhashi scoring system. Clinical findings including the back pain scale score, functional outcome, procedure related complications, and survival were assessed preoperatively, postoperatively, and then six months after the procedure. Results Twelve of the patients (86%) survived up to six months after the procedure. Three required mini-open decompressive laminectomy for severe epidural compression. Bone cement-augmented percutaneous screw fixation was performed one level above, one level below, and at the pathologic level itself. The mean operation time was 60 minutes (45–180) and blood loss was less than 100 mL. Prior to surgery, the mean pain score on the visual analogue scale was 8.8, while one month after the procedure, it had reduced to 3.0; this improvement was maintained until the six-month assessment in the surviving patients. All patients were able to sit within the first two days after surgery, and no patient experienced neurological deterioration at the one-month follow up after the surgery. No patient experienced screw loosening during the six months of follow-up. Asymptomatic cement leakage into the epidural space was observed in two patients, but no major complications were observed. Conclusion For selected patients with malignant spinal metastases, bone cement-augmented percutaneous screw fixation can provide significant pain relief and improve quality of life. PMID:28264239

  5. Percutaneous Implantation of a Catheter with Subcutaneous Reservoir for Intraarterial Regional Chemotherapy: Technique and Preliminary Results

    SciTech Connect

    Grosso, Maurizio; Zanon, Claudio; Mancini, Andrea; Garruso, Matteo; Gazzera, Carlo; Anselmetti, Giovanni Carlo; Veglia, Simona; Gandini, Giovanni

    2000-03-15

    Purpose: We present the technique and the preliminary results of percutaneous implantation of intraarterial catheters connected to a subcutaneous infusion reservoir for prolonged regional chemotherapy of hepatic and extrahepatic tumors.Methods: Two hundred patients with primary or secondary hepatic neoplasms, pelvic, pancreatic, renal, lingual, and breast cancer underwent the procedure. The access was the left axillary artery (188 patients) and the femoral artery (12 patients). The catheter tip was placed in the hepatic (170 patients), hypogastric (18), splenic (4), internal thoracic (2), gastroduodenal (3), renal (2) or the external carotid artery (1). The catheter was connected to a subcutaneous reservoir and filled with heparin; chemotherapeutic infusion was subsequently started.Results: One hundred percent immediate technical success was obtained. Forty-three of 200 (21.5%) patients had a complication: 29 patients had a catheter dislodgment, nine had arterial thrombosis, three had a pseudoaneurysm of the left axillary artery and two had a port pocket hematoma. Most complications (37/43, 86%) were treated percutaneously without interruption of chemotherapy. In only six cases (3% of the total population) was chemotherapy discontinued due to the complication itself. The mean duration of catheter patency was 7.2 months.Conclusion: Percutaneous placement of an intraarterial catheter is feasible and causes less discomfort to the patient than the surgical approach. The technique has an acceptable complication rate (21.5%), similar to that for surgical implantation (17.8%), with the advantage that in most cases the complications can be resolved percutaneously. This technique represents an alternative to surgical implantation in the treatment of liver metastases from colorectal cancer and opens new therapeutic possibilities for the local prolonged treatment of other kinds of tumor, though its clinical efficacy must be assessed in selected trials.

  6. Laparoscopic-Assisted Percutaneous Endoscopic Gastrostomy.

    PubMed

    Thaker, Adarsh M; Sedarat, Alireza

    2016-09-01

    There are a variety of techniques for gastrostomy tube placement. Endoscopic and radiologic approaches have almost entirely superseded surgical placement. However, an aging population and significant advancements in modern healthcare have resulted in patients with increasingly complex medical issues or postsurgical anatomy. The rising prevalence of obesity has also created technical challenges for proceduralists of many specialties. When patients with these comorbidities develop the need for long-term enteral nutrition and feeding tube placement, standard approaches such as percutaneous endoscopic gastrostomy (PEG) by endoscopists and percutaneous image-guided gastrostomy (PIG) by interventional radiologists may be technically difficult or impossible. For these challenging situations, laparoscopic-assisted PEG (LAPEG) is an alternative option. LAPEG combines the advantages of PEG with direct intraperitoneal visualization, helping ensure a safe tube placement tract free of intervening organs or structures. In this review, we highlight some of the important factors of first-line gastrostomy techniques, with an emphasis on the utility and procedural technique of LAPEG when they are not feasible.

  7. Laparoscopic-Assisted Percutaneous Endoscopic Transgastrostomy Jejunostomy

    PubMed Central

    Dimofte, Mihail-Gabriel; Nicolescu, Simona; Ristescu, Irina; Lunca, Sorinel

    2014-01-01

    Background and Objectives: New therapeutic protocols for patients with end-stage Parkinson disease include a carbidopa/levodopa combination using continuous, modulated enteral administration via a portable pump. The typical approach involves a percutaneous endoscopic transgastrostomy jejunostomy (PEG-J), which requires a combination of procedures designed to ensure that no organ is interposed between the abdominal wall and the gastric surface. Lack of transillumination in maximal endoscopic light settings is a major contraindication for PEG-J, and we decided to use a different approach to establish enteric access for long-term medication delivery via pump, using a minimally invasive procedure. Methods: In all patients, we performed a laparoscopic-assisted percutaneous transgastrostomy jejunostomy (LAPEG-J) after an unsuccessful endoscopic transillumination. Results: Five patients with end-stage Parkinson disease were referred to our department after successful therapeutic testing with administration of levodopa/carbidopa via naso-jejunal tube. All patients failed the endoscopic transillumination during the endoscopic procedure and were considered for LAPEG-J. In all patients, the LAPEG-J procedure was uneventful. The most common reason identified for failed transillumination was a high position of the stomach, followed by interposition of the liver or colon between the stomach and anterior abdominal wall. There were no complications regarding the LAPEG-J procedure, and all patients were discharged during the second postprocedural day. Conclusions: LAPEG-J provides a simple and safe option for placing a jejunostomy after an unsuccessful PEG-J attempt. PMID:25489214

  8. Percutaneous drainage of enteric-related abscesses.

    PubMed

    Fulcher, A S; Turner, M A

    1996-12-01

    Percutaneous drainage is a routinely performed radiologic procedure used in the management of abdominal abscesses. This technique has become the preferred method of treatment for most abdominal and pelvic abscesses, specifically those of enteric origin related to surgical procedures, appendicitis, diverticulitis, and Crohn disease. The well-documented safety and therapeutic efficacy of percutaneous abscess drainage (PAD) lead to the acceptance of this procedure as the primary means of managing abdominal abscesses, obviating the need for surgery in many instances. PAD may provide definitive therapy or may serve as a temporizing measure before delayed surgical treatment. Although PAD was originally reserved for treatment of unilocular, relatively superficial fluid collections, the role of PAD has evolved such that it is now used to manage complex multilocular fluid collections and abscesses that lie deep within the abdomen or pelvis. Although the standard transabdominal approach is preferred, a variety of approaches, including transgastric, transrectal, transvaginal, and transgluteal, may be used. PAD is performed using CT or sonographic guidance.

  9. Percutaneous toxicity of anticoagulant warfarin in rats.

    PubMed

    Kataranovski, Milena; Mirkov, Ivana; Vrankovic, Jelena; Kataranovski, Dragan; Subota, Vesna

    2008-01-01

    Percutaneous toxicity of anticoagulant rodenticides is usually manifested by coagulopathy and/or fatal outcome. There are, however, virtually no data on other biological effects of this class of pesticides that gain access into the organism via skin. In this study, percutaneous toxicity of epicutaneously applied warfarin was evaluated by measuring changes in peripheral blood granulocytes in rats. Application of 10 mug (0.05 mg/kg) or 100 mug (0.5 mg/kg) of warfarin (WF) for 3 consecutive days resulted in an increase in prothrombin time, documenting the access of warfarin to systemic circulation. Application of warfarin led to an increase in relative numbers of granulocytes at higher dose, whereas both doses resulted in increased metabolical viability, evaluated by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) reduction assay. Higher warfarin dose resulted in both granulocyte activation and priming (evaluated by cytochemical nitroblue tetrazolium, NBT, reduction assay of respiratory burst), whereas only a tendency toward activation was noted at lower WF dose. Soluble mediators from the circulation seem responsible for the observed effects, as exogenous plasma from WF-treated animals stimulated NBT reduction by isologous or naïve granulocytes. Data presented in this study are relevant for the recognition of biological effects, other than those affecting hemostasis, of anticoagulant rodenticides that gain access to systemic circulation through the skin.

  10. [Percutaneous tracheostomy in the ventilated patient].

    PubMed

    Añón, J M; Araujo, J B; Escuela, M P; González-Higueras, E

    2014-04-01

    The medical indications of tracheostomy comprise the alleviation of upper airway obstruction; the prevention of laryngeal and upper airway damage due to prolonged translaryngeal intubation in patients subjected to prolonged mechanical ventilation; and the facilitation of airway access for the removal of secretions. Since 1985, percutaneous tracheostomy (PT) has gained widespread acceptance as a method for creating a surgical airway in patients requiring long-term mechanical ventilation. Since then, several comparative trials of PT and surgical tracheostomy have been conducted, and new techniques for PT have been developed. The use of percutaneous dilatation techniques under bronchoscopic control are now increasingly popular throughout the world. Tracheostomy should be performed as soon as the need for prolonged intubation is identified. However a validated model for the prediction of prolonged mechanical ventilation is not available, and the timing of tracheostomy should be individualized. The present review analyzes the state of the art of PT in mechanically ventilated patients--this being regarded by many as the technique of choice in performing tracheostomy in critically ill patients.

  11. Percutaneous gallbladder aspiration for acute cholecystitis

    PubMed Central

    Rassameehiran, Supannee; Nugent, Kenneth

    2016-01-01

    Early cholecystectomy for patients with acute cholecystitis may not be possible in some clinical settings. Percutaneous gallbladder aspiration (PGBA) offers an alternative approach, but the benefits and risks of this procedure are unclear. We synthesized data on the outcomes of PGBA in acute cholecystitis patients using data sources from online databases, including MEDLINE and EMBASE, and bibliographies of included studies from January 2000 through December 2015. Two reviewers independently reviewed and critiqued the quality of each study. Seven eligible studies met our criteria. The success rates in single PGBA and repetitive PGBA (2–4 times) were 50% to 93% and 76% to 96%, respectively. Complication rates were 0% to 8% and were unrelated to the size of needle gauge used for aspiration and the number of aspirations. Salvage percutaneous cholecystostomy (PC) and urgent surgery were required in 0% to 43% of patients and 0% to 4% of patients, respectively. Two studies with antibiotic instillation had clinical success rates of 95% and 96%. In conclusion, repetitive PGBA combined with antibiotic instillation and salvage PC are useful alternatives to early cholecystectomy in patients with acute cholecystitis. PMID:27695167

  12. Midazolam sedation for percutaneous liver biopsy.

    PubMed

    Alexander, J A; Smith, B J

    1993-12-01

    Control of patient respiration is needed to safely perform percutaneous liver biopsy (PLB) and may be adversely affected by sedation. The purpose of this study was to evaluate the safety of PLB with intravenous midazolam and to evaluate patient acceptance of PLB with and without sedation. Two hundred seventeen consecutive patients underwent 301 percutaneous liver biopsies. One hundred fifty-one of the biopsies were done after the patients were sedated with intravenous midazolam immediately before the biopsy. The last 61 patients were questioned after the biopsy to evaluate the discomfort of the procedure, their memory of the procedure, and their willingness to undergo another PLB. The major complication rate was similar in the midazolam-treated (0.7%) and untreated (0.7%) groups. The midazolam-treated patients had a numerically lower mean pain score (1.5 +/- 0.4 vs 4.0 +/- 0.7) (mean +/- SEM) (P = 0.07) and significantly lower mean memory score (4.8 +/- 0.7 vs 9.9 +/- 0.1) (P < 0.01) than the untreated patients. The treated and untreated groups had similar mean willingness for repeat PLB scores (9.3 +/- 0.3 vs 9.1 +/- 0.6). We conclude that: (1) there is no increased risk of PLB with midazolam and (2) patients have less memory of the procedure with midazolam.

  13. Percutaneous tracheostomy in patients on anticoagulants

    PubMed Central

    Pasin, Laura; Frati, Elena; Cabrini, Luca; Landoni, Giovanni; Nardelli, Pasquale; Bove, Tiziana; Calabrò, Maria Grazia; Scandroglio, Anna Mara; Pappalardo, Federico; Zangrillo, Alberto

    2015-01-01

    Aims: To determine if percutaneous tracheostomy is safe in critically ill patients treated with anticoagulant therapies. Settings and Design: Single-center retrospective study including all the patients who underwent percutaneous dilatational tracheostomy (PDT) placement over a 1-year period in a 14-bed, cardiothoracic and vascular Intensive Care Unit (ICU). Materials and Methods: Patients demographics and characteristics, anticoagulant and antiplatelet therapies, coagulation profile, performed technique and use of bronchoscopic guidance were retrieved. Results: Thirty-six patients (2.7% of the overall ICU population) underwent PDT over the study period. Twenty-six (72%) patients were on anticoagulation therapy, 1 patient was on antiplatelet therapy and 2 further patients received prophylactic doses of low molecular weight heparin. Only 4 patients had normal coagulation profile and were not receiving anticoagulant or antiplatelet therapies. Overall, bleeding of any severity complicated 19% of PDT. No procedure-related deaths occurred. Conclusions: PDT was proved to be safe even in critically ill-patients treated with anticoagulant therapies. Larger prospective studies are needed to confirm our findings. PMID:26139737

  14. Multiplanar transesophageal echocardiography for the evaluation and percutaneous management of ostium secundum atrial septal defects in the adult.

    PubMed

    Sobrino, Ayax; Basmadjian, Arsène J; Ducharme, Anique; Ibrahim, Reda; Mercier, Lise-Andrée; Pelletier, Guy B; Marcotte, François; Garceau, Patrick; Burelle, Denis; O'Meara, Eileen; Dore, Annie

    2012-01-01

    The purpose of this paper is to review the usefulness of multiplanar transesophageal echocardiography before, during and after percutaneous transcatheter closure of secundum atrial septal defects. Transesophageal echocardiography imaging techniques,including their role in patient selection, procedural guidance and immediate assessment of technical success and complications are described and discussed in this review. Percutaneous transcatheter closure is indicated for ostium secundum atrial septal defects of less than 40 mm in maximal diameter. The defect must have a favorable anatomy, with adequate rims of at least 5 mm to anchor the prosthesis. Transesophageal echocardiography plays a critical role before the procedure in identifying potential candidates for percutaneous closure and to exclude those with unfavorable anatomy or associated lesions, which could not be addressed percutaneously. Transesophageal echocardiography is also important during the procedure to guide the deployment of the device. After device deployment, the echocardiographer must assess the device (integrity, position and stability), residual shunt, atrio-ventricular valve regurgitation, obstruction to systemic or venous return and pericardial effusion, in order to determine procedural success and diagnose immediate complications.

  15. Comparison between bipolar pulsed radiofrequency and monopolar pulsed radiofrequency in chronic lumbosacral radicular pain

    PubMed Central

    Chang, Min Cheol; Cho, Yun Woo; Ahn, Sang Ho

    2017-01-01

    Abstract Background: Chronic lumbosacral radicular pain is a challenging medical problem with respect to therapeutic management. Many patients with lumbosacral radicular pain complain of persistent leg pain after transforaminal epidural steroid injection. Nowadays, pulsed radiofrequency (PRF) stimulation on the dorsal root ganglion (DRG) is widely used for controlling lumbosacral radicular pain. Methods: We evaluated the effect of bipolar PRF on the DRG for the management of lumbosacral radicular pain. In addition, we compared the effect of bipolar PRF to monopolar PRF. Fifty patients with chronic lumbosacral radicular pain were included in the study and randomly assigned to 1 of 2 groups, the bipolar or monopolar PRF group (n = 25 per group). Pain intensity was evaluated using a numeric rating scale (NRS) at pretreatment, and 1, 2, and 3 months after treatment. Results: When compared to the pretreatment NRS scores, patients in both groups showed a significant decrease in NRS scores at 1, 2, and 3 months after treatment. Reductions in the NRS scores over time were significantly larger in the bipolar PRF group. Three months after treatment, 19 patients (76.0%) in the bipolar PRF group and 12 patients (48.0%) in the monopolar PRF group reported successful pain relief (pain relief of ≥50%). Conclusion: The use of bipolar PRF on the DRG can be an effective and safe interventional technique for chronic refractory lumbosacral radiculopathy, particularly in patients whose pain are refractory to epidural steroid injection or monopolar PRF stimulation. PMID:28248888

  16. Percutaneous Relief of Tension Pneumomediastinum in a Child

    SciTech Connect

    Chau, Helen Hoi-lun; Kwok, Philip Chong-hei; Lai, Albert Kwok-hung; Fan, Tsz Wo; Chan, Susan Chi-hum; Miu, Ting Yat; Chan, Grace Lai-har

    2003-11-15

    The purpose of this article was to describe the experience of relieving tension pneumomediastinum by a fluoroscopic-guided percutaneous method. We inserted a percutaneous drainage catheter with a Heimlich valve under fluoroscopic guidance to relieve the tension pneumomediastinum in a 2-year-old girl who suffered from dermatomyositis with lung involvement. This allowed immediate relief without the need for surgery. The procedure was repeated for relapsed tension pneumomediastinum. Good immediate results were achieved in each attempt. We conclude that percutaneous relief of pneumomediastinum under fluoroscopic guidance can be performed safely and rapidly in patients not fit for surgery.

  17. Percutaneous pulmonary valve endocarditis: incidence, prevention and management.

    PubMed

    Patel, Mehul; Malekzadeh-Milani, Sophie; Ladouceur, Magalie; Iserin, Laurence; Boudjemline, Younes

    2014-11-01

    The epidemiology of infective endocarditis is changing rapidly due to the emergence of resistant microorganisms, the indiscriminate use of antibiotics, and an increase in the implantation of cardiovascular devices including percutaneous valves. Percutaneous pulmonary valve implantation has achieved standard of care for the management of certain patients with right ventricular outflow tract dysfunction. With its expanding use, several cases of early and delayed infective endocarditis with higher morbidity and mortality rates have been reported. This review summarizes the trends in percutaneous pulmonary valve infective endocarditis, postulates proposed mechanisms, and elaborates on the prevention and management of this unique and potentially fatal complication.

  18. Percutaneous Mechanical Support in Cardiogenic Shock: A Review

    PubMed Central

    Gilani, Fahad Syed; Farooqui, Sarah; Doddamani, Rajiv; Gruberg, Luis

    2015-01-01

    Cardiogenic shock (CS) is a life-threatening condition associated with significant morbidity and mortality. Pharmacological therapy is often the first line of treatment but mechanical support can provide substantial hemodynamic improvement in refractory CS. Percutaneous mechanical support devices are placed in a minimally invasive manner and provide life-saving assistance to the failing myocardium. We review the percutaneous devices currently available, the evidence behind their use, and the new advances in percutaneous technology being evaluated for the treatment of CS. PMID:26052235

  19. Updates on Percutaneous Radiologic Gastrostomy/Gastrojejunostomy and Jejunostomy

    PubMed Central

    Park, Auh-Whan

    2010-01-01

    Gastrostomy placement for nutritional support for patients with inadequate oral intake has been attempted using surgical, endoscopic, and, more recently, percutaneous radiologically guided methods. Surgical gastrostomy has been superseded by both endoscopic and radiologic gastrostomy. We describe herein the indications, contraindications, patient preparations, techniques, complications, and aftercare with regard to radiologic gastrostomy. In addition, we discuss the available tube types and their perceived advantages. There remain some controversies regarding gastropexy performance and primary percutaneous gastrojejunostomy. Percutaneous jejunostomy is indicated for patients whose stomach is inaccessible for gastrostomy placement or for those who have had a previous gastrectomy. PMID:21103291

  20. Updates on percutaneous radiologic gastrostomy/gastrojejunostomy and jejunostomy.

    PubMed

    Shin, Ji Hoon; Park, Auh-Whan

    2010-09-01

    Gastrostomy placement for nutritional support for patients with inadequate oral intake has been attempted using surgical, endoscopic, and, more recently, percutaneous radiologically guided methods. Surgical gastrostomy has been superseded by both endoscopic and radiologic gastrostomy. We describe herein the indications, contraindications, patient preparations, techniques, complications, and aftercare with regard to radiologic gastrostomy. In addition, we discuss the available tube types and their perceived advantages. There remain some controversies regarding gastropexy performance and primary percutaneous gastrojejunostomy. Percutaneous jejunostomy is indicated for patients whose stomach is inaccessible for gastrostomy placement or for those who have had a previous gastrectomy.

  1. Rectouterine fistula after laparoscopic ultrasound-guided radiofrequency ablation of a uterine fibroid

    PubMed Central

    Jeong, Hyo Joo; Kwon, Byung-Su; Choi, Young Joon

    2014-01-01

    In the conservative management of uterine fibroids is radiofrequency ablation (RFA) considered to be one of the safe, effective and minimal invasive approaches in selected women who desire to retain their uterus. Few studies were conducted on its adverse outcomes and most of the reported complications were minor events such as pain, discharge, adhesion which didn't require any intervention. However, although safe and effective, the RFA of a uterine myoma can be the cause for severe complications such as penetration and burn injuries of pelvic organs. In general, a rectouterine fistula is one of the rarest complications but can lead to serious adverse outcomes. Herein, to our knowledge, we report the first case involving a rectouterine fistula after laparoscopic ultrasound-guided RFA of a uterine myoma with pelvic endometriosis. In addition, we provide a brief review of the relevant literature. PMID:25469349

  2. Rectouterine fistula after laparoscopic ultrasound-guided radiofrequency ablation of a uterine fibroid.

    PubMed

    Jeong, Hyo Joo; Kwon, Byung-Su; Choi, Young Joon; Huh, Chu Yeop

    2014-11-01

    In the conservative management of uterine fibroids is radiofrequency ablation (RFA) considered to be one of the safe, effective and minimal invasive approaches in selected women who desire to retain their uterus. Few studies were conducted on its adverse outcomes and most of the reported complications were minor events such as pain, discharge, adhesion which didn't require any intervention. However, although safe and effective, the RFA of a uterine myoma can be the cause for severe complications such as penetration and burn injuries of pelvic organs. In general, a rectouterine fistula is one of the rarest complications but can lead to serious adverse outcomes. Herein, to our knowledge, we report the first case involving a rectouterine fistula after laparoscopic ultrasound-guided RFA of a uterine myoma with pelvic endometriosis. In addition, we provide a brief review of the relevant literature.

  3. Percutaneous Microwave Ablation of Renal Angiomyolipomas

    SciTech Connect

    Cristescu, Mircea; Abel, E. Jason; Wells, Shane Ziemlewicz, Timothy J.; Hedican, Sean P.; Lubner, Megan G. Hinshaw, J. Louis Brace, Christopher L. Lee, Fred T.

    2016-03-15

    PurposeTo evaluate the safety and efficacy of US-guided percutaneous microwave (MW) ablation in the treatment of renal angiomyolipoma (AML).Materials and MethodsFrom January 2011 to April 2014, seven patients (5 females and 2 males; mean age 51.4) with 11 renal AMLs (9 sporadic type and 2 tuberous sclerosis associated) with a mean size of 3.4 ± 0.7 cm (range 2.4–4.9 cm) were treated with high-powered, gas-cooled percutaneous MW ablation under US guidance. Tumoral diameter, volume, and CT/MR enhancement were measured on pre-treatment, immediate post-ablation, and delayed post-ablation imaging. Clinical symptoms and creatinine were assessed on follow-up visits.ResultsAll ablations were technically successful and no major complications were encountered. Mean ablation parameters were ablation power of 65 W (range 60–70 W), using 456 mL of hydrodissection fluid per patient, over 4.7 min (range 3–8 min). Immediate post-ablation imaging demonstrated mean tumor diameter and volume decreases of 1.8 % (3.4–3.3 cm) and 1.7 % (27.5–26.3 cm{sup 3}), respectively. Delayed imaging follow-up obtained at a mean interval of 23.1 months (median 17.6; range 9–47) demonstrated mean tumor diameter and volume decreases of 29 % (3.4–2.4 cm) and 47 % (27.5–12.1 cm{sup 3}), respectively. Tumoral enhancement decreased on immediate post-procedure and delayed imaging by CT/MR parameters, indicating decreased tumor vascularity. No patients required additional intervention and no patients experienced spontaneous bleeding post-ablation.ConclusionOur early experience with high-powered, gas-cooled percutaneous MW ablation demonstrates it to be a safe and effective modality to devascularize and decrease the size of renal AMLs.

  4. Percutaneous gastrojejunostomy in amyotrophic lateral sclerosis.

    PubMed

    Strong, M J; Rowe, A; Rankin, R N

    1999-10-31

    We have performed a retrospective review of the use of a percutaneous gastrojejunostomy in patients with amyotrophic lateral sclerosis (ALS). Forty-one patients with initial bulbar manifestations of ALS and 32 patients with initial limb manifestations underwent a percutaneous gastrojejunostomy under fluoroscopic control using the Rankin gastrojejunostomy tube. Survival characteristics were compared with 86 bulbar onsetting and 207 limb onsetting ALS patients who did not require nutritional support. The 30-day mortality rate was 9.6% (respiratory death in three bulbar onsetting patients and four limb onsetting patients) and the 30 day morbidity rate was 4.1% (one operative site infection and intraperitoneal leakage in two patients). The most frequent long-term complication was the requirement for tube changing (blockage in six; dislodgment in two). Gastric reflux was not described amongst the treated patients. Overall survivorship (symptom onset to death) was less in the bulbar onsetting patients receiving a gastrojejunostomy tube than in the control population (median survival 22.0 vs. 33.7 months, respectively, P=0.005). As a group, the median survivorship for limb onsetting patients was not different for those receiving a gastrojejunostomy than for those who did not. However, a significant reduction in survival was observed in limb onsetting patients receiving a gastrojejunostomy early in the course of their disease (P=0.001) compared to those with a longer duration prior to the procedure. This was not observed in the bulbar onsetting patients. In both patient populations, no relationship was observed between survival post-gastrojejunostomy and the severity of pulmonary involvement at the time of the intervention, serum chloride, or age at onset. These studies demonstrate that a percutaneous gastrojejunostomy is a well-tolerated and safe alternative technique for enteral nutritional support in ALS patients. It also offers the advantage of not requiring either a

  5. Radiofrequency thermal ablation in painful myeloma of the clavicle.

    PubMed

    Gharaei, Helen; Imani, Farnad; Vakily, Masoud

    2014-01-01

    A 57-year-old male patient had myeloma. He had severe pain in the left clavicle that did not respond to radiotherapy; therefore, it was treated with radiofrequency thermal ablation (RFTA). Under fluoroscopic guidance, two RF needles at a distance of 1.5 cm from each other were inserted into the mass and conventional radiofrequency (90℃ and 60 seconds) at two different depths (1 cm apart) was applied. Then, 2 ml of 0.5% ropivacaine along with triamcinolone 40 mg was injected in each needle. The visual analogue pain score (VAS from 0 to 10) was decreased from 8 to 0. In the next 3 months of follow-up, the patient was very satisfied with the procedure and the mass gradually became smaller. There were no complications. This study shows that RFTA could be a useful method for pain management in painful osteolytic myeloma lesions in the clavicle.

  6. Radiofrequency Thermal Ablation in Painful Myeloma of the Clavicle

    PubMed Central

    Imani, Farnad; Vakily, Masoud

    2014-01-01

    A 57-year-old male patient had myeloma. He had severe pain in the left clavicle that did not respond to radiotherapy; therefore, it was treated with radiofrequency thermal ablation (RFTA). Under fluoroscopic guidance, two RF needles at a distance of 1.5 cm from each other were inserted into the mass and conventional radiofrequency (90℃ and 60 seconds) at two different depths (1 cm apart) was applied. Then, 2 ml of 0.5% ropivacaine along with triamcinolone 40 mg was injected in each needle. The visual analogue pain score (VAS from 0 to 10) was decreased from 8 to 0. In the next 3 months of follow-up, the patient was very satisfied with the procedure and the mass gradually became smaller. There were no complications. This study shows that RFTA could be a useful method for pain management in painful osteolytic myeloma lesions in the clavicle. PMID:24478905

  7. Irrigated Tip Catheters for Radiofrequency Ablation in Ventricular Tachycardia

    PubMed Central

    Grothoff, Matthias; Dinov, Borislav; Kosiuk, Jedrzej; Richter, Sergio; Sommer, Philipp; Breithardt, Ole A.; Bollmann, Andreas; Arya, Arash; Hindricks, Gerhard

    2015-01-01

    Radiofrequency (RF) ablation with irrigated tip catheters decreases the likelihood of thrombus and char formation and enables the creation of larger lesions. Due to the potential dramatic consequences, the prevention of thromboembolic events is of particular importance for left-sided procedures. Although acute success rates of ventricular tachycardia (VT) ablation are satisfactory, recurrence rate is high. Apart from the progress of the underlying disease, reconduction and the lack of effective transmural lesions play a major role for VT recurrences. This paper reviews principles of lesion formation with radiofrequency and the effect of tip irrigation as well as recent advances in new technology. Potential areas of further development of catheter technology might be the improvement of mapping by better substrate definition and resolution, the introduction of bipolar and multipolar ablation techniques into clinical routine, and the use of alternative sources of energy. PMID:25705659

  8. A radio-frequency sheath model for complex waveforms

    SciTech Connect

    Turner, M. M.; Chabert, P.

    2014-04-21

    Plasma sheaths driven by radio-frequency voltages occur in contexts ranging from plasma processing to magnetically confined fusion experiments. An analytical understanding of such sheaths is therefore important, both intrinsically and as an element in more elaborate theoretical structures. Radio-frequency sheaths are commonly excited by highly anharmonic waveforms, but no analytical model exists for this general case. We present a mathematically simple sheath model that is in good agreement with earlier models for single frequency excitation, yet can be solved for arbitrary excitation waveforms. As examples, we discuss dual-frequency and pulse-like waveforms. The model employs the ansatz that the time-averaged electron density is a constant fraction of the ion density. In the cases we discuss, the error introduced by this approximation is small, and in general it can be quantified through an internal consistency condition of the model. This simple and accurate model is likely to have wide application.

  9. Percutaneous Retrieval of a Retained Jackson-Pratt Drain Fragment

    SciTech Connect

    Namyslowski, Jan; Halin, Neil J.; Greenfield, Alan J.

    1996-11-15

    A retained intraabdominal Jackson-Pratt drain fragment was percutaneously retrieved using an inflated angioplasty balloon that had been maneuvered inside of the drain lumen over a hydrophilic-coated steerable guidewire.

  10. Stomal Varices: Treatment by Percutaneous Transhepatic Coil Embolization

    SciTech Connect

    Kishimoto, Keiko; Hara, Akihiko; Arita, Takeshi; Tsukamoto, Katsuhiko; Matsui, Norichika; Kaneyuki, Toshihiro; Matsunaga, Naofumi

    1999-11-15

    Bleeding from stomal varices in a patient with portal hypertension, uncontrolled by surgical ligation and sclerotherapy, was well controlled by percutaneous transhepatic embolization with platinum and stainless-steel coils.

  11. Conchotome and needle percutaneous biopsy of skeletal muscle.

    PubMed Central

    Dietrichson, P; Coakley, J; Smith, P E; Griffiths, R D; Helliwell, T R; Edwards, R H

    1987-01-01

    Percutaneous muscle biopsy is an important and acceptable technique in the study of conditions involving human skeletal muscle. A review of 436 conchotome and needle muscle biopsies obtained over 18 months in this centre is presented. Images PMID:3694206

  12. Percutaneous image-guided biopsy of the musculoskeletal system.

    PubMed

    Welch, Brian T; Welch, Timothy J

    2011-09-01

    Percutaneous image-guided biopsy plays an important role in the management of multiple pathologic conditions involving the musculoskeletal system. The vast majority of these conditions require histologic diagnosis to guide decision making concerning treatment. Percutaneous image-guided biopsy has supplanted open surgical biopsy as the primary modality for tissue diagnosis in this patient cohort. The safety, efficacy, and clinical outcome of percutaneous image-guided biopsy for a multitude of musculoskeletal conditions are well documented. Improvements in needle design and image guidance have continued to further the efficacy and safety of this diagnostic technique. Complications associated with percutaneous biopsy are minimal compared with those seen in open surgical biopsy, whereas diagnostic accuracy is comparable to that of surgical biopsy.

  13. Radio-frequency dressing of multiple Feshbach resonances

    NASA Astrophysics Data System (ADS)

    Kaufman, A. M.; Anderson, R. P.; Hanna, Thomas M.; Tiesinga, E.; Julienne, P. S.; Hall, D. S.

    2009-11-01

    We demonstrate and theoretically analyze the dressing of several proximate Feshbach resonances in R87b using radio-frequency (rf) radiation. We present accurate measurements and characterizations of the resonances, and the dramatic changes in scattering properties that can arise through the rf dressing. Our scattering theory analysis yields quantitative agreement with the experimental data. We also present a simple interpretation of our results in terms of rf-coupled bound states interacting with the collision threshold.

  14. Computer simulations of ions in radio-frequency traps

    NASA Technical Reports Server (NTRS)

    Williams, A.; Prestage, J. D.; Maleki, L.; Djomehri, J.; Harabetian, E.

    1990-01-01

    The motion of ions in a trapped-ion frequency standard affects the stability of the standard. In order to study the motion and structures of large ion clouds in a radio-frequency (RF) trap, a computer simulation of the system that incorporates the effect of thermal excitation of the ions was developed. Results are presented from the simulation for cloud sizes up to 512 ions, emphasizing cloud structures in the low-temperature regime.

  15. Perforated-Layer Implementation Of Radio-Frequency Lenses

    NASA Technical Reports Server (NTRS)

    Dolgin, Benjamin P.

    1996-01-01

    Luneberg-type radio-frequency dielectric lenses made of stacked perforated circular dielectric sheets, according to proposal. Perforation pattern designed to achieve required spatial variation of permittivity. Consists of round holes distributed across face of each sheet in "Swiss-cheese" pattern, plus straight or curved slots that break up outer parts into petals in "daisy-wheel" pattern. Holes and slots made by numerically controlled machining.

  16. Effects of multipolar electrode radiofrequency energy delivery on ventricular endocardium

    SciTech Connect

    Oeff, M.; Langberg, J.J.; Franklin, J.O.; Chin, M.C.; Sharkey, H.; Finkbeiner, W.; Herre, J.M.; Scheinman, M.M. )

    1990-03-01

    This study examined the effects of radiofrequency energy applied in a bipolar fashion with single as compared with multiple sequential applications at the canine endocardium. In this closed-chest model, radiofrequency energy (750 kHz) was delivered between two adjacent poles of an electrode catheter. Single applications were performed at distinct sites in the left (n = 30) and right ventricles (n = 29) of 13 normal dogs. A multiple sequential technique, which enlarges the ablated endocardial surface, was applied in the left (n = 13) and right ventricles (n = 4) of seven normal dogs and six dogs with remote myocardial infarction. Single applications (199 +/- 200 joules) resulted in lesions with a volume of 0.12 +/- 0.06 cm3 (range 0.03 to 0.31 cm3) and an endocardial surface area of 0.29 +/- 0.15 cm2 (range 0.06 to 0.63 cm2). Changes at the catheter/tissue interface led to a rise in impedance, restricting further enlargement of the necrosis. Sequential delivery of radiofrequency energy between poles 1 and 2, 2 and 3, and 3 and 4 of a quadripolar electrode catheter repeated 9 to 11 times in slightly different positions allowed a cumulative energy of 6571 +/- 3857 joules to be applied to the endocardium, resulting in a lesion volume of 0.84 +/- 0.38 cm3, with an endocardial lesion surface area of 3.7 +/- 1.2 cm2 (range 2.9 to 5.1 cm2). Histologically, all radiofrequency lesions were restricted to the endocardium/subendocardium with a small border zone of injury. Aggressive stimulation techniques did not induce ventricular tachycardia in any of the dogs before and 19 +/- 11.4 days after multiple sequential ablations.

  17. CT-guided percutaneous aspiration of Tarlov cyst as a useful diagnostic procedure prior to operative intervention.

    PubMed

    Lee, J-Y; Impekoven, P; Stenzel, W; Löhr, M; Ernestus, R-I; Klug, N

    2004-07-01

    Tarlov or perineural cysts are lesions of the nerve root most often found in the sacral region. Several authors recommend surgical treatment of symptomatic Tarlov cysts. However, successful surgical treatment is dependent on appropriate patient selection. In this article, we report three cases of a sacral perineural cyst, causing sciatic pain, and emphasize the usefulness of CT-guided percutaneous aspiration as an important diagnostic and prognostic procedure prior to definitive operative treatment.

  18. Common Bile Duct Obstruction Due to Surgical Clips Following Laparoscopic Cholecystectomy Treated with Percutaneous Balloon Dilatation.

    PubMed

    Korkmaz, Mehmet; Adıgüzel, Ünal; Şanal, Bekir; Zeren, Sezgin; Ekici, Mehmet Fatih

    2016-06-01

    Bile duct injury is a commonly seen complication of the laparoscopic cholecystectomy (LC) approach, which can even lead to a life-threatening condition and endoscopic retrograde cholangiopancreatography (ERCP) is the first-line choice in treatment. Beside this, it can be concluded that percutaneous transhepatic cholangiography (PTC) and balloon dilatation methods may also constitute a reasonable selection with non-invasive, feasible and effective aspects prior to open surgery. In the present case, we report the management of a bile duct obstruction due to surgical clips following LC, treated with PTC and balloon dilatation instead of surgical procedure in a child patient.

  19. The Challenging Buried Bumper Syndrome after Percutaneous Endoscopic Gastrostomy

    PubMed Central

    Afifi, Ibrahim; Zarour, Ahmad; Al-Hassani, Ammar; Peralta, Ruben; El-Menyar, Ayman; Al-Thani, Hassan

    2016-01-01

    Buried bumper syndrome (BBS) is a rare complication developed after percutaneous endoscopic gastrostomy (PEG). We report a case of a 38-year-old male patient who sustained severe traumatic brain injury that was complicated with early BBS after PEG tube insertion. On admission, bedside PEG was performed, and 7 days later the patient developed signs of sepsis with rapid progression to septic shock and acute kidney injury. Abdominal CT scan revealed no collection or leakage of the contrast, but showed malpositioning of the tube bumper at the edge of the stomach and not inside of it. Diagnostic endoscopy revealed that the bumper was hidden in the posterolateral part of the stomach wall forming a tract inside of it, which confirmed the diagnosis of BBS. The patient underwent laparotomy with a repair of the stomach wall perforation, and the early postoperative course was uneventful. Acute BBS is a rare complication of PEG tube insertion which could be manifested with severe complications such as pressure necrosis, peritonitis and septic shock. Early identification is the mainstay to prevent such complications. Treatment selection is primarily guided by the presenting complications, ranging from simple endoscopic replacement to surgical laparotomy. PMID:27462190

  20. Percutaneous Nephrolithotomy: Current Clinical Opinions and Anesthesiologists Perspective

    PubMed Central

    Malik, Indira; Wadhwa, Rachna

    2016-01-01

    Percutaneous nephrolithotomy (PCNL), a minimally invasive method for removal of renal calculi, was initially started in the 1950s but gained popularity about two decades later and has now become standard practice for management. There has been an immense improvement in technique and various guidelines have been established for treatment of renal stones. However, it has its own share of complications which can be attributed to surgical technique as well as anesthesia related complications. PubMed and Google search yielded more than 30 articles describing the different complications seen in this procedure, out of which 15 major articles were selected for writing this review. The aim of this review article is to describe the implications of the complications associated with PCNL related to the anesthesiologist. The anesthesiologist is as much responsible for the management of the patient perioperatively as the surgeon. Therefore, it is mandatory to be familiar with the various complications, some of which may be life threatening and he should be able to manage them efficiently. The paper also analyses the advantages and drawbacks of the available options in anesthesia, that is, general and regional, both of which are employed for PCNL. PMID:27110239

  1. Risk predictors of retroperitoneal hemorrhage following percutaneous coronary intervention.

    PubMed

    Tiroch, Klaus A; Arora, Nipun; Matheny, Michael E; Liu, Christopher; Lee, Timothy C; Resnic, Frederic S

    2008-12-01

    Retroperitoneal hemorrhage (RPH) is a potentially catastrophic complication after percutaneous coronary intervention (PCI). Previous studies identified female gender, body surface area, and high arterial puncture location as independent risk factors for RPH. There have been conflicting reports regarding the association with vascular closure devices (VCDs). Chronic renal insufficiency (CRI) and diabetes mellitus have been associated with both peripheral vascular disease and vascular access-site complications. The putative association of VCDs, CRI, and diabetes mellitus with RPH in the contemporary PCI era was investigated. A total of 3,062 consecutive patients undergoing 3,482 PCIs at Brigham and Women's Hospital from January 2005 to April 2007 were evaluated for the study. All 3,311 patients with femoral angiography underwent hand-caliper-based quantitative vascular analysis and were included in this analysis. Multivariate analysis was performed using a backwards selection algorithm, and a propensity adjustment was developed to control for possible confounding variables regarding VCD use. The incidence of RPH was 0.49% (17 of 3,482 patients). After multivariate and propensity analyses, covariates that significantly influenced the risk of RPH were CRI, glycoprotein IIb/IIIa inhibitors, and high arterial puncture (p < or =0.007). VCD use was not independently associated with the development of RPH (p = 0.74). In conclusion, this large prospective cohort study identified CRI, but not VCD use, as an independent predictor for RPH and peripheral vascular disease.

  2. Robotic systems for percutaneous needle-guided interventions.

    PubMed

    Kettenbach, Joachim; Kronreif, Gernot

    2015-02-01

    Several groups have developed robotic systems for invasive medical procedures. In this article we will focus on selected robotic systems for percutaneous needle-guided interventions using CT or MR imaging. We present six interventional robotic systems designed to work with imaging modalities such as CT, Cone-beam CT and MRI. The details of each system are given along with any phantom, animal, or human trials performed with each particular robot. Although each of these systems has specific features, they are all of great clinical value since they provide very stable needle guidance -- even for angulated approaches, they may allow access to lesions when the width of the CT- or MR- gantry would limit the access for a biopsy needle or other interventional tools such as thermal ablation probes. Then, such a robot may be able to guide the needle into the most promising region of the lesion without the need for a second contrast injection. Thus, more efficacious characterization and treatment, particularly for lesions that are difficult to target, can be anticipated. Although more research and clinical trials are certainly needed, it is, however, our belief that robotic systems will be an important part of future interventions.

  3. The Challenging Buried Bumper Syndrome after Percutaneous Endoscopic Gastrostomy.

    PubMed

    Afifi, Ibrahim; Zarour, Ahmad; Al-Hassani, Ammar; Peralta, Ruben; El-Menyar, Ayman; Al-Thani, Hassan

    2016-01-01

    Buried bumper syndrome (BBS) is a rare complication developed after percutaneous endoscopic gastrostomy (PEG). We report a case of a 38-year-old male patient who sustained severe traumatic brain injury that was complicated with early BBS after PEG tube insertion. On admission, bedside PEG was performed, and 7 days later the patient developed signs of sepsis with rapid progression to septic shock and acute kidney injury. Abdominal CT scan revealed no collection or leakage of the contrast, but showed malpositioning of the tube bumper at the edge of the stomach and not inside of it. Diagnostic endoscopy revealed that the bumper was hidden in the posterolateral part of the stomach wall forming a tract inside of it, which confirmed the diagnosis of BBS. The patient underwent laparotomy with a repair of the stomach wall perforation, and the early postoperative course was uneventful. Acute BBS is a rare complication of PEG tube insertion which could be manifested with severe complications such as pressure necrosis, peritonitis and septic shock. Early identification is the mainstay to prevent such complications. Treatment selection is primarily guided by the presenting complications, ranging from simple endoscopic replacement to surgical laparotomy.

  4. Delayed Nephropleural Fistula After Percutaneous Nephrolithotomy

    PubMed Central

    Kaler, Kamaljot S.; Cwikla, Daniel

    2016-01-01

    Abstract Pleural effusions due to pleural injury following supracostal percutaneous nephrolithotomy (PCNL) occur in upwards of 15% of patients; however, these effusions are invariably diagnosed immediately postoperative or during the hospital stay. Herein, we report our initial experience with a delayed nephropleural fistula. A 52-year-old female underwent an uneventful supracostal right PCNL staghorn stone procedure and was discharged on postoperative day 1. She presented to the emergency department 8 days after her original procedure and one day after ureteral stent removal in the office, with right pleural effusion, concomitant contralateral renal colic secondary to migration of a left pelvic stone into her left proximal ureter, and acute renal failure/oliguria. She was treated with right chest tube drainage, bilateral nephrostomy tube placement, and subsequent left holmium laser ureterolithotripsy. PMID:27579431

  5. Tubeless percutaneous nephrolithotomy using hemostatic gelatin matrix.

    PubMed

    Borin, James F; Sala, Leandro G; Eichel, Louis; McDougall, Elspeth M; Clayman, Ralph V

    2005-01-01

    We describe using hemostatic gelatin matrix (FloSeal; Baxter Inc., Irvine, CA) to provide hemostasis of the tract after percutaneous nephrolithotomy, thereby obviating a nephrostomy tube. For patients who are rendered stone free, a 7F, 11.5-mm occlusion balloon catheter, passed retrograde, is used to occlude the collecting system at the level of entry of the 30F Amplatz sheath. FloSeal is then injected through the partially retracted Amplatz sheath while withdrawing the applicator and the sheath in tandem. The guidewire is withdrawn per urethra until its tip resides in the renal pelvis. A 36-cm, 7F tail stent is passed retrograde, and the skin is closed with cyanoacrylate adhesive (Ethicon, Somerville, NJ). A Foley catheter is placed, to be removed the next morning; the patient can be discharged on postoperative day 1. The ureteral stent is removed in 5 to 7 days as an outpatient procedure.

  6. Complications of the percutaneous kidney biopsy.

    PubMed

    Whittier, William L

    2012-05-01

    Percutaneous kidney biopsy is an integral part of a nephrologist's practice. It has helped to define nephrology as a subspecialty. When indicated, it is a necessary procedure to help patients, as it allows for diagnostic, prognostic, and therapeutic information. Although very safe, this procedure can give rise to complications, mainly related to bleeding. Since its development in the 1950s, modifications have been made to the approach and the technique, which have improved the diagnostic yield while keeping it a safe procedure. Alterations to the standard approach may be necessary if risk factors for bleeding are present. In addition, obesity, pregnancy, and solitary kidney biopsy are all special circumstances that change the procedure itself or the risk of the procedure. Today, kidney biopsy is a vital procedure for the nephrologist: clinically relevant, safe, and effective.

  7. Percutaneous endoscopic gastrostomy following previous abdominal surgery.

    PubMed Central

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

    1984-01-01

    During a 36-month period, 89 patients have undergone percutaneous endoscopic gastrostomy without mortality. Of these patients, 25 (13 infants and children, 12 adults) had prior abdominal procedures that increased their risk for the endoscopic procedure. With two exceptions, all gastrostomies were performed utilizing local anesthesia. There was one major complication, a gastrocolic fistula, which was successfully managed by repeating the endoscopic gastrostomy procedure at a location more cephalad in the stomach. Twenty-two of the gastrostomies were placed for feeding purposes and all of these patients were able to leave the hospital with alimentation accomplished via the tube. Three of the endoscopically placed gastrostomies were for gastrointestinal tract decompression. A total of 255 patient months have been accumulated in these patients with the endoscopically placed gastrostomy in situ. The technique can be safely performed in patients with prior abdominal surgery and in the majority of cases is the technique of choice for establishing a tube gastrostomy. PMID:6428334

  8. Magnetic electrical connectors for biomedical percutaneous implants

    NASA Technical Reports Server (NTRS)

    Owens, L. J. (Inventor)

    1977-01-01

    A biomedical percutaneous connector is described which includes a socket having an enlarged disk shaped base portion for being implanted below the patient's skin and cylindrical portion which is integral with the base portion and extends outwardly of the skin. A conical recess in an upper end of the cylindrical portion has a magnet located in the base. Inclined conductive strips are carried on an upper end of the cylindrical portion to which electrical conductors are attached and extend into the patient's body. A complementary shaped plug which also has electrical contacts provided thereon is adapted to fit within the conical recess of the socket. The plug is held in the socket by magnetic force.

  9. Percutaneous Vertebroplasty in Painful Schmorl Nodes

    SciTech Connect

    Masala, Salvatore Pipitone, Vincenzo; Tomassini, Marco; Massari, Francesco; Romagnoli, Andrea; Simonetti, Giovanni

    2006-02-15

    The Schmorl node represents displacement of intervertebral disc tissue into the vertebral body. Both Schmorl nodes and degenerative disc disease are common in the human spine. We performed a retrospective study, for the period from January 2003 to February 2005, evaluating 23 patients affected by painful Schmorl nodes, who underwent in our department percutaneous transpedicular injection of polymethylmethacrylate (vertebroplasty) in order to solve their back pain not responsive to medical and physical management. Eighteen patients reported improvement of the back pain and no one reported a worsening of symptoms. Improvement was swift and persistent in reducing symptoms. Painful Schmorl nodes, refractory to medical or physical therapy, should be considered as a new indication within those vertebral lesions adequately treatable utilizing Vertebroplasty procedure.

  10. Anesthetic Management in Radiofrequency Catheter Ablation of Ventricular Tachycardia

    PubMed Central

    Naeini, Payam S.; Razavi, Mehdi; Collard, Charles D.; Tolpin, Daniel A.; Anton, James M.

    2016-01-01

    Radiofrequency catheter ablation is increasingly being used to treat patients who have ventricular tachycardia, and anesthesiologists frequently manage their perioperative care. This narrative review is intended to familiarize anesthesiologists with preprocedural, intraprocedural, and postprocedural implications of this ablation. Ventricular tachycardia typically arises from structural heart disease, most often from scar tissue after myocardial infarction. Many patients thus affected will benefit from radiofrequency catheter ablation in the electrophysiology laboratory to ablate the foci of arrhythmogenesis. The pathophysiology of ventricular tachycardia is complex, as are the technical aspects of mapping and ablating these arrhythmias. Patients often have substantial comorbidities and tenuous hemodynamic status, necessitating pharmacologic and mechanical cardiopulmonary support. General anesthesia and monitored anesthesia care, when used for sedation during ablation, can lead to drug interactions and side effects in the presence of ventricular tachycardia, so anesthesiologists should also be aware of potential perioperative complications. We discuss variables that can help anesthesiologists safely guide patients through the challenges of radiofrequency catheter ablation of ventricular tachycardia. PMID:28100967

  11. Percutaneous techniques for tendon transfers in the foot and ankle.

    PubMed

    Panchbhavi, Vinod Kumar

    2014-03-01

    Tendon transfer procedures are useful for replacing a dysfunctional or diseased tendon or for restoring muscle imbalance. The tendon to be transferred is harvested as distal as is necessary to provide adequate length for rerouting and attachment at the different site. The harvesting of tendon itself can be attained using an open surgical approach or minimally invasive percutaneous techniques that limit surgical exposure. This article describes percutaneous techniques for tendon transfer procedures used to address foot and ankle disorders.

  12. Percutaneous ablation therapies of inoperable pancreatic cancer: a systematic review

    PubMed Central

    Ierardi, Anna Maria; Lucchina, Natalie; Bacuzzi, Alessandro; Marco, De Chiara; Bracchi, Elena; Cocozza, Eugenio; Dionigi, Gianlorenzo; Tsetis, Dimitrios; Floridi, Chiara; Carrafiello, Gianpaolo

    2015-01-01

    Initial studies about ablation therapies of the pancreas were associated with significant morbidity and mortality, which limited widespread adoption. Development of techniques with high quality imaging used as guidance improve outcomes reducing complications. Moreover, only few experiences of percutaneous pancreatic ablations are reported. They are performed by very skilled operators in highly specialized centers. This review presents the current status of percutaneous local ablative therapies in the treatment of advanced pancreatic cancer. PMID:26424487

  13. Open versus percutaneous dilatational tracheostomy: efficacy and cost analysis.

    PubMed

    Grover, A; Robbins, J; Bendick, P; Gibson, M; Villalba, M

    2001-04-01

    The economic advantages of percutaneous dilatational tracheostomies versus open tracheostomies in the operating room have been thoroughly evaluated. We are now reporting our comparison of the costs and charges of percutaneous dilatational tracheostomies with those of open bedside tracheostomies at our institution. The current literature comparing the two open techniques and the percutaneous method of placing tracheostomies was reviewed and the charges and costs for these procedures at our institution were compared. Patients were placed into one of three groups for analysis: open tracheostomies in the operating room (Group I), open tracheostomies in the intensive care unit (Group II), and percutaneous dilatational tracheostomies in the intensive care unit (Group III). Based on our own experience and a literature review it is evident that all three approaches to tracheostomies are safe. Economic analysis showed a savings of $180 in cost per procedure and a $658 savings in charges per procedure for the open method at the bedside when compared with the percutaneous method at the bedside. The professional fee for bronchoscopy was not included in this calculation; including this would lead to greater savings with the open method over the percutaneous method. Open tracheostomy in the operating room increased costs over the bedside procedure by $2194 and increased charges by $2871. For the 150 to 180 tracheostomies done each year at our institution utilization of the open technique at the bedside results in a cost savings of approximately $31,500 and a charge savings of $109,000 compared with the percutaneous dilatational tracheostomy. Both the open bedside and percutaneous dilatational methods are reasonable and safe options. However, the open bedside tracheostomy is a better utilization of resources and is more cost effective, and it is the procedure of choice at our institution.

  14. Superior Mesenteric Artery Embolism Treated with Percutaneous Mechanical Thrombectomy

    SciTech Connect

    Popovic, Peter Kuhelj, Dimitrij; Bunc, Matjaz

    2011-02-15

    A case of acute superior mesenteric artery embolism treated with percutaneous thrombus aspiration is described. A 63-year-old man with chronic atrial fibrillation was admitted to the hospital with progressive abdominal pain. Computed tomography angiography revealed an occlusion of the distal part of the superior mesenteric artery. The patient was effectively treated using transaxillary percutaneous mechanical thrombectomy using a 6F Aspirex thrombectomy catheter.

  15. Two-vessel chronic total occlusion. Complete percutaneous revascularisation

    PubMed Central

    Dębski, Artur; Opolski, Maksymilian P.; Kłopotowski, Mariusz; Karcz, Maciej A.; Witkowski, Adam

    2014-01-01

    Little is known about the success rate of second attempts to open chronic total occlusions. Two-vessel occlusion makes the procedure is even more challenging. Thus, embarking on complete percutaneous revascularization of such lesions requires adequate experience, especially after first unsuccessful attempt. We present a case of a 52-year-old male patient in whom successful percutaneous opening of two chronic coronary at staged procedure was performed. PMID:25489332

  16. Chest Wall Dissemination of Nocardiosis after Percutaneous Transthoracic Needle Biopsy

    SciTech Connect

    Shimamoto, Hiroshi Inaba, Yoshitaka; Yamaura, Hidekazu; Sato, Yozo; Kamiya, Mika; Miyazaki, Masaya; Arai, Yasuaki; Horio, Yoshitsugu

    2007-07-15

    We described a case of chest wall dissemination after percutaneous transthoracic needle biopsy. A 65-year-old man had a lung nodule which was suspected to be lung carcinoma. He underwent percutaneous transthoracic needle biopsy using an 18G semiautomated biopsy needle and pathologic diagnosis showed organizing pneumonia. Two months after the biopsy, chest wall dissemination occurred. Implantation of carcinoma along the biopsy route was suspected, but the mass was actually due to pulmonary nocardiosis.

  17. Factors predicting infectious complications following percutaneous nephrolithotomy

    PubMed Central

    Sharma, Kuldeep; Sankhwar, Satya Narayan; Goel, Apul; Singh, Vishwajeet; Sharma, Pradeep; Garg, Yogesh

    2016-01-01

    Objective: To determine the predictors of infectious complications following percutaneous nephrolithotomy (PCNL) in a prospective study. Materials and Methods: A total of 332 patients with renal or upper ureteric calculi who underwent PCNL between January 2013 and June 2014 were included in the study. Infectious complications included febrile urinary tract infection and septicemia. The patients were divided into Group A and B depending on whether they developed or did not develop infectious complications. Patient, stone, renal, and procedure-related factors were compared between the two groups. Results: There was no significant (P > 0.05) correlation among age (37.03 ± 16.24 vs. 36.72 ± 14.88), sex, and body mass index (21.00 ± 1.77 vs. 21.03 ± 2.25) between Group A and B. The patients in Group A were found to have significantly higher incidence of renal failure (39.5% vs. 9.2%,P= 0.0001), diabetes mellitus (12 [31.5%] vs. 33 [11.2%],P= 0.0001), previous percutaneous nephrostomy (PCN) tube placement (11 [28%] vs. 21 [7.1%]P= 0.0001), moderate to severe hydronephrosis (HDN), larger stone surface area (812.68 ± 402.07 vs. 564.92 ± 361.32,P= 0.0001), mean number of punctures (1.57 ± 0.50 vs. 1.20 ± 0.47,P= 0.002), and mean duration of surgery (94.28 ± 18.23 vs. 69.12 ± 21.23,P= 0.0001) than Group B. Conclusion: Post-PCNL infectious complications were found to be more common in patients with renal failure, diabetes mellitus, preoperative PCN placement, staghorn calculi, severe HDN, multiple punctures, and prolonged duration of surgery. PMID:28057987

  18. Renal Vein Injury During Percutaneous Nephrolithotomy Procedure

    PubMed Central

    Toffeq, Hewa Mahmood

    2016-01-01

    Abstract Background: Percutaneous nephrostolithotomy is an important approach for removing kidney stones. Puncturing and dilatation are two mandatory steps in percutaneous nephrolithotomy (PCNL). Uncommonly, during dilatation, the dilators can cause direct injury to the main renal vein or to their tributaries. Case Presentation: A 75-year-old female underwent PCNL for partial staghorn stone in the left kidney. During puncturing and dilatation, renal vein tributary was injured, and the nephroscope entered the renal vein and inferior vena cava, which was clearly recognized. Injection of contrast material through the nephroscope confirms the false pathway to the great veins (renal vein and inferior vena cava). Bleeding was controlled intraoperatively by applying Amplatz sheath over the abnormal tract, the procedure was continued and stones were removed. At the end of the procedure, a Foley catheter was used as a nephrostomy tube and its balloon was inflated inside the renal pelvis and pulled back with light pressure to the lower calix, which was the site of injury to the renal vein tributaries, then the nephrostomy tube was closed; by this we effectively controlled the bleeding. The patient remained hemodynamically stable; antegrade pyelography was done on the second postoperative day, there was distally patent ureter with no extravasation, neither contrast leak to renal vein, and was discharged home at third postoperative day. After 2 weeks, the nephrostomy tube was gradually removed in the operative room, without bleeding, on the next day, Double-J stent was removed. Conclusion: Direct injury and false tract to the renal vein tributaries during PCNL can result in massive hemorrhage, and can be treated conservatively in hemodynamically stable patients, using a nephrostomy catheter as a tamponade. PMID:27704054

  19. Percutaneous Management of Biliary Strictures After Pediatric Liver Transplantation

    SciTech Connect

    Miraglia, Roberto Maruzzelli, Luigi; Caruso, Settimo; Riva, Silvia; Spada, Marco; Luca, Angelo; Gridelli, Bruno

    2008-09-15

    We analyze our experience with the management of biliary strictures (BSs) in 27 pediatric patients who underwent liver transplantation with the diagnosis of BS. Mean recipient age was 38 months (range, 2.5-182 months). In all patients percutaneous transhepatic cholangiography, biliary catheter placement, and bilioplasty were performed. In 20 patients the stenoses were judged resolved by percutaneous balloon dilatation and the catheters removed. Mean number of balloon dilatations performed was 4.1 (range, 3-6). No major complications occurred. All 20 patients are symptom-free with respect to BS at a mean follow-up of 13 months (range, 2-46 months). In 15 of 20 patients (75%) one course of percutaneous stenting and bilioplasty was performed, with no evidence of recurrence of BS at a mean follow-up of 15 months (range, 2-46 months). In 4 of 20 patients (20%) two courses of percutaneous stenting and bilioplasty were performed; the mean time to recurrence was 9.8 months (range, 2.4-24 months). There was no evidence of recurrence of BS at a mean follow-up of 12 months (range, 2-16 months). In 1 of 20 patients (5%) three courses of percutaneous stenting and bilioplasty were performed; there was no evidence of recurrence of BS at a mean follow-up of 10 months. In conclusion, BS is a major problem following pediatric liver transplantation. Radiological percutaneous treatment is safe and effective, avoiding, in most cases, surgical revision of the anastomosis.

  20. [Endovascular radiofrequency denervation of renal arteries as an innovation method of treatment of refractory arterial hypertension. First experience in Russia].

    PubMed

    Danilov, N M; Matchin, Iu G; Chazova, I E

    2012-01-01

    Excessive activation of the sympathetic nervous system forms the basis of pathogenesis of essential arterial hypertension (AH). The present work was aimed at evaluating efficacy and safety of endovascular radiofrequency denervation of renal arteries in patients with AH refractory AH based on the initial first experience in with using this methodology in the Russian Federation. The interventions were carried out on December 14-15th, 2011 in the first five patients presenting with AH refractory to antihypertensive therapy consisting of three and more drugs in therapeutic doses, one of which was a diuretic. The selection criteria were systolic arterial pressure (SAP) ≥160 mm Hg or ≥150 mm Hg in the presence of type 2 diabetes mellitus. The obligatory conditions for selection were the preserved renal function [glomerular filtration rate (GFR) ≥45 ml/min] and the absence of the secondary form of AH. The procedure of denervation was performed in the conditions of roentgen-operating room using special Medtronic Ardian Simplicity Catheter System™. In all cases we managed to perform bilateral denervation of renal arteries with the radiofrequency effect in not less than 4 zones of each of vessels. Efficacy of each of the effect was registered with due regard for reaching certain temperature and values of impedance. The interventions were not accompanied by the development of any complications either in the area of manipulations or the site of puncture. Neither were there any complications from the side of the cardiovascular or excretory systems of the body. Diurnal monitoring of AP (DMAP) registered a significant decrease in SAP averagely from 174±12 to 145±10 mm Hg three days after the intervention. A persistent antihypertensive effect was confirmed by the DMAP findings one month after denervation - the SAP level averagely amounted to 131±6 mm Hg. Endovascular radiofrequency denervation of renal arteries is a safe and efficient method of treatment of AH resistant

  1. Radiofrequency turbinate volume reduction vs. radiofrequency-assisted turbinectomy for nasal obstruction caused by inferior turbinate hypertrophy.

    PubMed

    Kumar, Saumitra; Anand, Trivender Singh; Pal, Indranil

    2017-02-01

    Radiofrequency procedures are a well-accepted treatment for nasal obstruction. We conducted a randomized, noncontrolled study to compare the effectiveness of submucosal bipolar radiofrequency turbinate volume reduction (RFTVR) and bipolar radiofrequency-assisted turbinectomy (RFaT) in patients presenting with nasal obstruction caused by inferior turbinate hypertrophy. A total of 30 patients-15 males and 15 females, aged 15 to 60 years (mean: 32)-were randomly divided into one of the two homogeneous treatment groups. Outcomes were determined by comparisons of subjective symptom scores on a visual analog scale and by anterior active rhinomanometry at postoperative days 7, 14, and 28 and again at 6 months postoperatively. Both groups demonstrated significant and similar improvements in nasal airway function both subjectively and objectively. However, we noted that the incidence of adverse effects and postoperative morbidity was higher in the RFaT group. Therefore, we conclude that when surgery is indicated, RFTVR is the preferred treatment for nasal obstruction secondary to inferior turbinate hypertrophy. RFaT is equally effective, but it is associated with a slightly higher incidence of adverse effects.

  2. Extrapedicular Infiltration Anesthesia as an Improved Method of Local Anesthesia for Unipedicular Percutaneous Vertebroplasty or Percutaneous Kyphoplasty

    PubMed Central

    2016-01-01

    Aim. This report introduces extrapedicular infiltration anesthesia as an improved method of local anesthesia for unipedicular percutaneous vertebroplasty or percutaneous kyphoplasty. Method. From March 2015 to March 2016, 44 patients (11 males and 33 females) with osteoporotic vertebral compression fractures with a mean age of 71.4 ± 8.8 years (range: 60 to 89) received percutaneous vertebroplasty or percutaneous kyphoplasty. 24 patients were managed with conventional local infiltration anesthesia (CLIA) and 20 patients with both CLIA and extrapedicular infiltration anesthesia (EPIA). Patients evaluated intraoperative pain by means of the visual analogue score and were monitored during the procedure for additional sedative analgesia needs and for adverse nerve root effects. Results. VAS of CLIA + EPIA and CLIA group was 2.5 ± 0.7 and 4.3 ± 1.0, respectively, and there was significant difference (P = 0.001). In CLIA group, 1 patient required additional sedative analgesia, but in CLIA + EPIA group, no patients required that. In the two groups, no adverse nerve root effects were noted. Summary. Extrapedicular infiltration anesthesia provided good local anesthetic effects without significant complications. This method deserves further consideration for use in unipedicular percutaneous vertebroplasty and percutaneous kyphoplasty. PMID:27766261

  3. Evaluation of the safety and efficacy of radiofrequency ablation for treating benign thyroid nodules

    PubMed Central

    Tang, Xiaoyin; Cui, Dan; Chi, Jiachang; Wang, Zhi; Wang, Tao; Zhai, Bo; Li, Ping

    2017-01-01

    Background: Radiofrequency ablation (RFA) is a relatively new procedure for treating benign thyroid nodules. The purpose of this study was to evaluate the safety and efficacy of RFA for treating benign thyroid nodules so as to serve as a reference for future clinical practice. Methods: This study retrospectively analyzed the clinical data of patients receiving percutaneous RFA for treating thyroid nodules from November 2014 to July 2015 in our medical center. One hundred and eight patients with a total of 380 nodules received ultrasound-guided RFA for treating thyroid nodules. Comparisons of the volume change of thyroid nodules before and after RFA treatment, post-treatment complication, and change of thyroid function, were carried out afterwards. Results: Before treatments, all patients received fine needle aspiration biopsy (FNA) which supported the diagnosis of benign tumor. There were 13 males and 95 females included in the study. Twenty-six cases (24.07%) had single nodule, and 82 cases (75.93%) had multiple nodules. Before treatments, the thyroid functions (FT3, FT4, and TSH) were normal originally or adjusted to normal range by endocrinology treatment. The preoperative nodules had minimum volume of 0.01mL, maximum volume of 70.89 mL, and mean volume of 1.02 ± 4.24mL. The volume of nodules one month and three months after RFA were 0.29 ± 0.72mL and 0.15 ± 0.87mL, respectively. In addition, volume reduction ratio (VRR) of nodules one month and three months after RFA were 64.12% and 85.54%, respectively. Both volume of nodules and VRR had statistically significant differences for pre-operative and post-operative comparison (P<0.05). Thyroid functions were in normal range after treatments, and there was no serious complications. Conclusions: Ultrasound-guided RFA treating benign thyroid nodules had the advantages of definite efficacy, safety, strong in control ability, no incision, less damage to surrounding normal tissues and no effect on thyroid function

  4. Treatment of Extraspinal Painful Bone Metastases with Percutaneous Cementoplasty: A Prospective Study of 50 Patients

    SciTech Connect

    Anselmetti, Giovanni Carlo Manca, Antonio; Ortega, Cinzia; Grignani, Giovanni; DeBernardi, Felicino; Regge, Daniele

    2008-11-15

    The aim of this study was to assess the efficacy of percutaneous cementoplasty (PC) with polymethylmethacrylate (PMMA) in painful extravertebral lytic bone metastases not responding to conventional therapy. Fifty patients (25 females), mean age 64.7 {+-} 11.2 years, underwent PC after giving informed consent. Procedures were performed under fluoroscopy (1/50) or combined fluoroscopy-CT (49/50) guidance in local anesthesia or under deep sedation in 7 patients with large metastases who underwent radiofrequency thermoablation (RFA) in the same session. Seventy lesions were treated (1-6 per patient; average, 1.4 {+-} 0.9), arranging in size from 1 to 10 cm (average, 3.6 {+-} 2.1 cm). Mean volume of PMMA per lesion was 5.9 {+-} 3.2 ml (range, 1.5-15.0 ml). Pain was prospectively evaluated on an 11-point visual analog scale (VAS) before and after the procedure (follow-up, 15 to 36 months). Mean VAS score dropped from 9.1 {+-} 1.2 (range: 6-10) to 2.1 {+-} 2.5 (range: 0-9). Mean VAS difference was 7.0 {+-} 2.3 (range, 1-10; p < 0.0001, Wilcoxon signed rank test). Forty-seven of the 50 patients (94%) suspended narcotic drugs, in 22 (44%) pain was controlled with a nonsteroidal anti-inflammatory drug, in 25 (50%) analgesic therapy was suspended, and 13 of 50 (26%) had complete pain regression. In 3 of the 50 patients (6%) pain was not improved. No statistical difference between osteoplasty and osteoplasty plus RFA was found (p = 0.8338, Mann-Whitney test). No complications arose during the procedure. Two patients with metastases in the femoral diaphysis reported a fracture 1 month after treatment. PC is effective to obtain pain regression in painful bone metastases not responding to conventional analgesic therapy; bone consolidation cannot be obtained in the diaphysis of long weight-bearing bones.

  5. Temperature Measurement During Polymerization of Bone Cement in Percutaneous Vertebroplasty: An In Vivo Study in Humans

    SciTech Connect

    Anselmetti, Giovanni Carlo Manca, Antonio; Kanika, Khanna; Murphy, Kieran; Eminefendic, Haris; Masala, Salvatore; Regge, Daniele

    2009-05-15

    Aim of the study was to 'in vivo' measure temperature, during percutaneous vertebroplasty (PV), within a vertebral body injected with different bone cements. According to the declaration of Helsinki, 22 women (60-80 years; mean, 75 years) with painful osteoporotic vertebral collapse underwent bilateral transpedicular PV on 22 lumbar vertebrae. Two 10-G vertebroplasty needles were introduced into the vertebra under digital fluoroscopy; a 16-G radiofrequency thermoablation needle (Starburst XL; RITA Medical System Inc., USA), carrying five thermocouples, was than coaxially inserted. Eleven different bone cements were injected and temperatures were measured every 30 s until temperatures dropped under 45{sup o}C. After the thermocouple needle was withdrawn, bilateral PV was completed with cement injection through the vertebroplasty needle. Unpaired Student's t-tests, Kruskal-Wallis test, and Wilcoxon signed rank test were used to evaluate significant differences (p < 0.05) in peak temperatures, variations between cements, and clinical outcome. All procedures were completed without complications, achieving good clinical outcomes (p < 0.0001). Regarding average peak temperature, cements were divided into three groups: A (over 60{sup o}C), B (from 50{sup o} to 60{sup o}C), and C (below 50{sup o}C). Peak temperature in Group A (86.7 {+-} 10.7{sup o}C) was significantly higher (p = 0.0172) than that in Groups B (60.5 {+-} 3.7{sup o}C) and C (44.8 {+-} 2.6{sup o}C). The average of all thermocouples showed an extremely significant difference (p = 0.0002) between groups. None of the tested cements maintained a temperature {>=}45{sup o}C for more than 30 min. These data suggest that back-pain improvement is obtained not by thermal necrosis but by mechanical consolidation only. The relative necrotic thermal effect in vertebral metastases seems to confirm that analgesia must be considered the main intent of PV.

  6. Radio-Frequency (RF) Devices for Safeguards: Where We Are and Where We Need to Go

    SciTech Connect

    Rowe, Nathan C; Younkin, James R; Pickett, Chris A; Whitaker, J Michael

    2011-01-01

    Radio-Frequency (RF) devices have revolutionized many aspects of modern industrial processes. RF technology can enable wireless communication for tag identification, sensor communication, and asset tracking. Radio-frequency identification (RFID) is a technology that utilizes wireless communication to interrogate and identify an electronic tag attached to an item in order to identify the item. The technology can come in many forms: passive or active tags, low to ultra-wideband frequencies, small paper-thin tags to brick-sized units, and simple tags or highly integrated sensor packages. RF technology, and specifically RFID, has been applied widely in commercial markets for inventory, supply chain management, and asset tracking. Several recent studies have demonstrated the safeguards benefits of utilizing RFID versus conventional inventory tagging methods for tracking nuclear material. These studies have indicated that the RF requirements for safeguards functions are more stringent than the RF requirements for other inventory tracking and accounting applications. Additionally, other requirements must be addressed, including environmental and operating conditions, authentication, and tag location and attachment. Facility restrictions on radio spectrum, method of tag attachment, and sensitivity of the data collected impact the tag selection and system design. More important, the intended use of the system must be considered. The requirements for using RF to simply replace or supplement container identifiers such as bar codes that facilitate the inventory function will differ greatly from the requirements for deploying RF for unattended monitoring applications. Several studies have investigated these considerations to advance commercial RF devices for safeguards use, and a number of system concepts have been developed. This paper will provide an overview of past studies and current technologies, and will investigate the requirements, existing gaps, and several potential

  7. Should anyone perform percutaneous endoscopic laser diskectomy and percutaneous lumbar disc decompressions?

    PubMed Central

    Epstein, Nancy E.

    2016-01-01

    Background: Increasingly, pain management specialists (P-S) (e.g., anesthesiologists, radiologists, or physiatrists), who are not spinal surgeons, are performing percutaneous endoscopic laser diskectomy (PELD), percutaneous lumbar disc decompression (PLDD), and target percutaneous laser disc decompression (T-PLDD) in patients with minimal/mild disc herniations. Here, theoretically, the laser vaporizes/shrinks a small portion of disc tissue that lowers intradiscal pressure/volume, and thereby provides “symptomatic relief” (e.g., low back pain/radiculopathy). Nevertheless, the vast majority of these patients experience spontaneous relief of their complaints over several months without any intervention. Methods: A literature review revealed that P-S specialists are performing PELD/PLDD/T-PLDD to address minimal/mild disc herniations. However, multiple well-designed studies confirmed that PELD/PLDD/T-PLDD were ineffective for managing acute/chronic pain in these patients. Results: Several randomized clinical trials documented the lack of clinical efficacy of PELD/PLDD/T-PLLD procedures over microdiskectomy. PELD/PLDD/T-PLDD correlated with only 60–70% success rates with higher reoperation rates (e.g., up to 38%) vs. 90% success rates for routine microdiskectomy (e.g., with faster recovery and only 16% reoperation rates). Nevertheless, without surgical training, P-S are performing these procedures and are, therefore, unable to adddress perioperative/postoperative PELD/PLDD/T-PLDD surgical complications. Conclusions: Pain management specialists, who are not trained spinal surgeons, should not perform PELD/PLDD/T-PLDD surgery to treat minimal/mild disc herniations. Not only do most of these discs resolve spontaneously over several months but also they are largely ineffective. Furthermore, there is no evidence to support the superiority of PELD/PLDD/T-PLDD procedures over microdiskectomy even if performed by spinal specialists. PMID:28144489

  8. Percutaneous Radiologic, Surgical Endoscopic, and Percutaneous Endoscopic Gastrostomy/Gastrojejunostomy: Comparative Study and Cost Analysis

    SciTech Connect

    Barkmeier, Jeffrey M.; Trerotola, Scott O.; Wiebke, Eric A.; Sherman, Stuart; Harris, Veronica J.; Snidow, John J.; Johnson, Matthew S.; Rogers, Wendy J.; Zhou Xiaohua

    1998-07-15

    Purpose: To compare the results and costs of three different means of achieving direct percutaneous gastroenteric access. Methods: Three groups of patients received the following procedures: fluoroscopically guided percutaneous gastrostomy/gastrojejunostomy (FPG, n= 42); percutaneous endoscopic gastrostomy/gastrojejunostomy (PEG, n= 45); and surgical endoscopic gastrostomy/gastrojejunostomy (SEG, n= 34). Retrospective review of the medical records was performed to evaluate indications for the procedure, procedure technical success, and outcome. Estimated costs were compared for each of the three procedures, using a combination of charges and materials costs. Results: Technical success was greater for FPG and SEG (100% each) than for PEG (84%, p= 0.008 vs FPG and p= 0.02 vs SEG). All patients (n= 7) who failed PEG subsequently underwent successful FPG. Success in placing a gastrojejunostomy was 91% for FPG, and estimated at 43% for PEG and 0 for SEG. Complications did not differ in frequency among groups. For gastrostomy, the average cost per successful tube was lowest in the PEG group ($1862, p= 0.02); FPG averaged $1985, and SEG $3694. SEG costs significantly more than FPG or PEG (p= 0.0001). For gastrojejunostomy, FPG averaged $2201, PEG $3158, and SEG $3045. Conclusion: Technical success for gastrostomy is higher for FPG and SEG than PEG. Though PEG is the least costly procedure, the difference is modest compared with FPG. For gastrojejunostomy, FPG offers the highest technical success rate and lowest cost. Due to high costs associated with the operating room, SEG should be reserved for those patients undergoing a concurrent surgical procedure.

  9. Major Bleeding after Percutaneous Image-Guided Biopsies: Frequency, Predictors, and Periprocedural Management

    PubMed Central

    Kennedy, Sean A.; Milovanovic, Lazar; Midia, Mehran

    2015-01-01

    Major bleeding remains an uncommon yet potentially devastating complication following percutaneous image-guided biopsy. This article reviews two cases of major bleeding after percutaneous biopsy and discusses the frequency, predictors, and periprocedural management of major postprocedural bleeding. PMID:25762845

  10. Percutaneous mitral valve repair for mitral regurgitation.

    PubMed

    Block, Peter C

    2003-02-01

    Mitral regurgitation (MR) associated with, ischemic, and degenerative (prolapse) disease, contributes to left ventricular (LV) dysfunction due to remodeling, and LV dilation, resulting in worsening of MR. Mitral valve (MV) surgical repair has provided improvement in survival, LV function and symptoms, especially when performed early. Surgical repair is complex, due to diverse etiologies and has significant complications. The Society for Thoracic Surgery database shows that operative mortality for a 1st repair is 2% and for re-do repair is 4 times that. Cardiopulmonary bypass and cardiac arrest are required. The attendant morbidity prolongs hospitalization and recovery. Alfieri simplified mitral repair using an edge-to-edge technique which subsequently has been shown to be effective for multiple etiologies of MR. The MV leaflers are typically brought together by a central suture producing a double orifice MV without stenosis. Umana reported that MR decreased from grade 3.6 +/- 0.5 to 0.8 +/- 0.4 (P < 0.0001) and LV ejection fraction increased from 33 +/- 13% to 45 +/- 11% (P = 0.0156). In 121 patients, Maisano reported freedom from re-operation of 95 +/- 4.8% with up to 6 year follow-up. Oz developed a MV "grasper" that is directly placed via a left ventriculotomy and coapts both leaflets which are then fastened by a graduated spiral screw. An in-vitro model using explanted human valves showed significant reduction in MR and in canine studies, animals followed by serial echo had persistent MV coaptation. At 12 weeks the device was endothelialized. These promising results have paved the way for a percutaneous or minimally invasive-off pump mitral repair. Evalve has developed catheter-based technology, which, by apposing the edges of a regurgitant MV, results in edge-to-edge repair. Release of the device is done after echo and fluoroscopic evaluation under normal loading conditions. If the desired effect is not produced the device can be repositioned or retrieved

  11. Ultra-extended euthermic pulsed radiofrequency for the treatment of ophthalmic neuralgia: A case report with elaboration of a new technique

    PubMed Central

    Bhatjiwale, Mohinish G.; Bhatjiwale, Mrudul M.; Bhagat, Ami

    2016-01-01

    Background: Pulsed radiofrequency although present for many years has been used little compared to ablative procedures for pain relief. Its use in trigeminal neuralgia is sparse and unreported in the ophthalmic division, where the possibility of sensory loss can lead to high morbidity. We wished to explore the potential of this reportedly safe modality for a prolonged duration in a highly sensitive anatomic neural location, however, in a very secure, structured, and staged manner. Case Description: A patient suffering from ophthalmic division (V1) medically uncontrolled neuralgia with a preoperative visual analog scale (VAS) score of 9/10 was subjected to a percutaneous pain relief procedure. The patient was treated with prolonged duration pulsed radiofrequency (PRF) for 40 min, with corneal sensation monitoring under conscious sedation keeping a low voltage (7 V) and tip temperature at 37°C. The patient obtained immediate relief, which was verified on the operation table itself. Postoperative VAS score of 0/10 was recorded. More than 6 months after the procedure, the patient is completely free from neuralgic pain and continues to have a VAS score of 0/10. Conclusion: As opposed to conventional PRF where mostly a tip temperature of 42°C and high voltage have been used for 2 to a maximum of 8 min, PRF with a tip temperature of 37°C and a safe voltage of 7 V over an ultra-extended duration of 40 min can give a more distinct and effective but equally safe result. Although our case verified the safety and efficacy of prolonged duration PRF in sensitive anatomic locations, more studies are warranted for establishing this as a standard line of treatment. The specific use of PRF in ophthalmic division neuralgia in the manner described in our case report has hitherto not been reported in medical literature and will open a new vista in the minimally invasive treatment of this disease. PMID:27990312

  12. Percutaneous therapy of low stage and grade urothelial neoplasia: long-term follow up.

    PubMed

    Montanari, Emanuele; Del Nero, Alberto; Bernardini, Paolo; Mangiarotti, Barbara; Confalonieri, Silvia; Grisotto, Massimo; Cordima, Giovanni

    2005-12-01

    Nephroureterectomy with the excision of the ipsilateral ureteral orifice and bladder cuff has been considered the standard treatment of the urinary upper transitional cell carcinoma. With the advent of sophisticated techniques for the endo-urologic management of many benign urologic diseases of the upper tract, there has been growing enthusiasm for the application of these same techniques in the management of upper tract TCC, which is also supported by recent advances in the development of small calibre telescopes with improved optics and the development of small calibre adjunctive instruments and laser fibers. A large number of cases published in the literature has confirmed the safety and efficacy of percutaneous treatment in selected patients with upper tract TCC of low grade and stage. Between 1997 and 2005 we treated 62 pts (37 pelvic transitional cell carcinoma and 25 ureteral). 4 pts (5 renal units: 4 T1G2 and 1 TaG1) underwent percutaneous resection for a tumor in a solitary kidney (2 cases), one case for bilateral neoplasm, and in the other case the lesion was unilateral with chronic renal failure. After preoperative evaluation, (excretory urography, computerized tomography and ureteroscopy with biopsy to confirm the low stage and grade of the lesion) the tumor was resected using an Amplatz sheat of 26-30 Fr and a 24 Fr resectoscope to keep a low intra-caliceal pressure. The tumor base was biopsied and fulgurated After 48 h, contrastography to assure integrity of the urinary system was performed and Mitomycin C was infused over 24 h. Second-look nephroscopy with multiple biopsies was performed in all cases 7 days later and 8 Ch nephrostomy was placed. If the biopsies resulted negative the patient was submitted to 6 weekly endocavitary instillation of BCG through the nephrostomy tube. All pts at a mean follow up of 71 months were tumor free. One patient presented a bladder relapse after 83 months. No complication of percutaneous resection was observed. The

  13. Effect of Radiofrequency Radiation on Human Hematopoietic Stem Cells.

    PubMed

    Gläser, Katharina; Rohland, Martina; Kleine-Ostmann, Thomas; Schrader, Thorsten; Stopper, Helga; Hintzsche, Henning

    2016-11-01

    Exposure to electromagnetic fields in the radiofrequency range is ubiquitous, mainly due to the worldwide use of mobile communication devices. With improving technologies and affordability, the number of cell phone subscriptions continues to increase. Therefore, the potential effect on biological systems at low-intensity radiation levels is of great interest. While a number of studies have been performed to investigate this issue, there has been no consensus reached based on the results. The goal of this study was to elucidate the extent to which cells of the hematopoietic system, particularly human hematopoietic stem cells (HSC), were affected by mobile phone radiation. We irradiated HSC and HL-60 cells at frequencies used in the major technologies, GSM (900 MHz), UMTS (1,950 MHz) and LTE (2,535 MHz) for a short period (4 h) and a long period (20 h/66 h), and with five different intensities ranging from 0 to 4 W/kg specific absorption rate (SAR). Studied end points included apoptosis, oxidative stress, cell cycle, DNA damage and DNA repair. In all but one of these end points, we detected no clear effect of mobile phone radiation; the only alteration was found when quantifying DNA damage. Exposure of HSC to the GSM modulation for 4 h caused a small but statistically significant decrease in DNA damage compared to sham exposure. To our knowledge, this is the first published study in which putative effects (e.g., genotoxicity or influence on apoptosis rate) of radiofrequency radiation were investigated in HSC. Radiofrequency electromagnetic fields did not affect cells of the hematopoietic system, in particular HSC, under the given experimental conditions.

  14. Effects of radiofrequency exposure on the GABAergic system in the rat cerebellum: clues from semi-quantitative immunohistochemistry.

    PubMed

    Mausset, A L; de Seze, R; Montpeyroux, F; Privat, A

    2001-08-31

    The widespread use of cellular phones raises the problem of interaction of electromagnetic fields with the central nervous system (CNS). In order to measure these effects on neurotransmitter content in the CNS, we developed a protocol of neurotransmitter detection based on immunohistochemistry and image analysis. Gamma-vinyl-GABA (GVG), an inhibitor of the GABA-transaminase was injected in rats to increase GABA concentration in the CNS. The cellular GABA contents were then revealed by immunohistochemistry and semi-quantified by image analysis thanks to three parameters: optical density (O.D.), staining area, and number of positive cells. The increase in cerebellar GABA content induced by GVG 1200 mg/kg was reflected in these three parameters in the molecular and the granular layers. Therefore, control of immunohistochemistry parameters, together with appropriate image analysis, allowed both the location and the detection of variations in cellular neurotransmitter content. This protocol was used to investigate the effects of exposure to 900 MHz radiofrequencies on cerebellar GABA content. Both pulsed emission with a specific absorption rate (SAR) of 4 W/kg and continuous emission with high SAR (32 W/kg) were tested. We observed a selective diminution of the stained processes area in the Purkinje cell layer after exposure to pulsed radiofrequency and, in addition, a decrease in O.D. in the three cell layers after exposure to continuous waves. Whether this effect is, at least partly, due to a local heating of the tissues is not known. Overall, it appears that high energetic radiofrequency exposure induces a diminution in cellular GABA content in the cerebellum.

  15. Septic thrombophlebitis: percutaneous mechanical thrombectomy and thrombolytic therapies.

    PubMed

    Kar, Subrata; Webel, Richard

    2014-01-01

    Suppurative thrombophlebitis (Lemierre's syndrome) of the internal jugular vein is a rare and sometimes fatal complication. It commonly occurs from oropharyngeal infections, peripheral lines, complications from dental procedures, gingivitis, or central venous catheterizations. Empiric antibiotics are the initial treatment of choice followed by thrombolytics or surgical thrombectomy in refractory cases. We present a case of septic thrombophlebitis of the right internal jugular vein from a peripherally inserted central venous catheter. We also review the current percutaneous mechanical thrombectomy and thrombolytics therapies for such a rare disorder. Mechanical thrombectomy includes rotational thrombectomy or rheolytic therapies. Devices include the Amplatz thrombectomy device (Microvena), the Arrow-Trerotola Percutaneous thrombolytic device (Arrow), and the Cragg-Casteneda thrombolytic brush (Microtherapeutics). Rheolytic therapies include Angiojet, the Hydrolyzer, and the Oasis Thrombectomy System. Percutaneous mechanical thrombectomy techniques include rotational fragmentation, aspiration or suction thrombectomy, and hydrodynamic thrombectomy. AngioJet catheters may be used for percutaneous embolectomy in conjunction with pulse spray techniques, which instill thrombolytics locally. Thrombolytics include streptokinase, urokinase, and recombinant-tissue plasminogen activator. Mechanical thrombectomy combined with thrombolytics provide optimal treatment results secondary to their complementary effects. Therefore, patients who are refractory to standard medical therapy and considered poor surgical candidates may benefit from combined percutaneous mechanical thrombectomy with thrombolytics to achieve superior results if no contraindications exist for thrombolytics.

  16. Postoperative seizure following transforaminal percutaneous endoscopic lumbar discectomy

    PubMed Central

    Kertmen, Hayri; Gürer, Bora; Yilmaz, Erdal Resit; Sekerci, Zeki

    2016-01-01

    Endoscopic surgery for lumbar disc herniation has been available for more than 30 years. Transforaminal percutaneous endoscopic lumbar discectomy is a well-known, safe, and effective method used for the treatment of the lumbar disc herniation. The published complications of the transforaminal percutaneous endoscopic lumbar discectomy consist of infections, thrombophlebitis, dysesthesia, dural tear, vascular injury, and death. Seizure after transforaminal percutaneous endoscopic lumbar discectomy is an extremely rare complication. A 20-year-old patient applied at our department who had undergone transforaminal percutaneous endoscopic lumbar. During the procedure, while performing the discography, non-ionic contrast media was administered into the thecal sac inadvertently. Two hours after surgery, the patient developed generalized tonic-clonic seizure of 5-min duration. Diagnosis of iohexol-induced seizure was made and the patient was treated supportively without anti-epileptics. Here we present the first case of seizure after transforaminal percutaneous endoscopic lumbar discectomy, which was caused by inadvertent administration of the contrast media into the thecal sac. PMID:27695562

  17. Percutaneous Treatment of Splenic Cystic Echinococcosis: Results of 12 Cases

    SciTech Connect

    Akhan, Okan Akkaya, Selçuk; Dağoğlu, Merve Gülbiz; Akpınar, Burcu; Erbahçeci, Aysun; Çiftçi, Türkmen; Köroğlu, Mert; Akıncı, Devrim

    2016-03-15

    PurposeCystic echinococcosis (CE) in the spleen is a rare disease even in endemic regions. The aim of this study was to examine the efficacy of percutaneous treatment for splenic CE.Materials and MethodsTwelve patients (four men, eight women) with splenic CE were included in this study. For percutaneous treatment, CE1 and CE3A splenic hydatid cysts were treated with either the PAIR (puncture, aspiration, injection, respiration) technique or the catheterization technique.ResultsEight of the hydatid cysts were treated with the PAIR technique and four were treated with catheterization. The volume of all cysts decreased significantly during the follow-up period. No complication occurred in seven of 12 patients. Abscess developed in four patients. Two patients underwent splenectomy due to cavity infection developed after percutaneous treatment, while the spleen was preserved in 10 of 12 patients. Total hospital stay was between 1 and 18 days. Hospital stay was longer and the rate of infection was higher in the catheterization group. Follow-up period was 5–117 months (mean, 44.8 months), with no recurrence observed.ConclusionThe advantages of the percutaneous treatment are its minimal invasive nature, short hospitalization duration, and its ability to preserve splenic tissue and function. As the catheterization technique is associated with higher abscess risk, we suggest that the PAIR procedure should be the first percutaneous treatment option for splenic CE.

  18. [Clinical monitoring in areas of exposure to radiofrequency electromagnetic fields].

    PubMed

    Suvorov, I M

    2013-01-01

    Clinical syndromes induced by high intensity radiofrequency electromagnetic field chronic exposure are described. Persons injured by occupational exposure have been observed central nervous system changes in diencephalic syndrome form, cardio-vascular system changes revealed in atherosclerosis, isch(a)emic heart disease and coronary insufficiency rapid progressive expansion. General public living in territory of radar station exposure zone different functional disorders have been identified: vegetative dystonia (asthenovegetative syndrome), thrombocytopenia, decrease of blood coagulation index, and thyroid gland function changes. Observed diseases clinical variability may be determined by electromagnetic exposure characteristics.

  19. Cost analysis of radiofrequency catheter ablation for atrial fibrillation.

    PubMed

    Gorenek, Bulent; Kudaiberdieva, Gulmira

    2013-09-10

    Atrial fibrillation is the most common arrhythmia associated with increased mortality and morbidity. Its management requires high healthcare expenditures; 52%-70% of expenses for AF care are constituted by hospitalization costs. The current management strategies of pharmacological rhythm control and pharmacological or invasive rate control show no difference in impact on major outcomes in patients with AF. Radiofrequency catheter ablation (RFA) has been shown to reduce the risk of AF recurrence, improve quality of life and reduce hospitalization rate as compared to pharmacological rhythm control and rate control strategies. This review summarizes current knowledge on cost and cost-effectiveness analysis of RFA for patients with atrial fibrillation.

  20. Ethical implications of implantable radiofrequency identification (RFID) tags in humans.

    PubMed

    Foster, Kenneth R; Jaeger, Jan

    2008-08-01

    This article reviews the use of implantable radiofrequency identification (RFID) tags in humans, focusing on the VeriChip (VeriChip Corporation, Delray Beach, FL) and the associated VeriMed patient identification system. In addition, various nonmedical applications for implanted RFID tags in humans have been proposed. The technology offers important health and nonhealth benefits, but raises ethical concerns, including privacy and the potential for coercive implantation of RFID tags in individuals. A national discussion is needed to identify the limits of acceptable use of implantable RFID tags in humans before their use becomes widespread and it becomes too late to prevent misuse of this useful but ethically problematic technology.