118 results on '"Terraz S"'
Search Results
102. Unusual Masses of the Pancreas to Be Aware of.
- Author
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Genevay M, Dumonceau JM, Berney T, Terraz S, Felley C, Morel P, and Frossard JL
- Abstract
This paper aims at emphasizing the difficulty in assessing preoperatively the diagnosis of solid masses of the pancreas whatever the initial clinical presentation may be. We illustrate our purpose describing consecutive cases of pancreatic masses of the pancreas we recently had and who were followed according to the internal guidelines of investigation of our referral hospital. Whereas malignant tumors of the pancreas represent the vast majority of solid tumors of the pancreas, other diagnoses must be evoked. We report three cases of pancreatic solid masses that were explored by endoscopic ultrasonography coupled with fine needle aspiration, a method universally considered to be both reliable and accurate but which failed to assess definitive diagnosis due to both cytological pitfalls and sampling error.
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- 2009
- Full Text
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103. Intravenous leiomyomatosis of the uterus: link with new fertilisation methods?
- Author
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Robert-Ebadi H, Terraz S, Mach N, Dubuisson JB, Kalangos A, and Bounameaux H
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- Adult, Angiomyoma etiology, Angiomyoma surgery, Female, Humans, Iliac Vein surgery, Leiomyomatosis complications, Uterine Neoplasms complications, Angiomyoma pathology, Iliac Vein pathology, Leiomyomatosis pathology, Uterine Neoplasms pathology
- Published
- 2009
- Full Text
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104. [Minimally invasive ablation techniques for small kidney tumors: cryoablation and radiofrequency].
- Author
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Caviezel A, Terraz S, Becker CD, and Iselin C
- Subjects
- Cryotherapy, Humans, Kidney Neoplasms radiotherapy, Kidney Neoplasms therapy, Radio Waves, Cryosurgery methods, Kidney Neoplasms surgery, Minimally Invasive Surgical Procedures methods
- Abstract
Over the last years, the development of minimally invasive surgery using percutaneous or laparoscopic ablative techniques for the treatment of small renal tumours has become more common. Cryotherapy and radiofrequency option have been now integrated in the armamentarium of the urologist. These approaches seem to be an attractive alternative to extirpative surgery in selected high-risk patients and offer on a short time basis equivalent cancer control to conventional surgery. This review presents recent data with regard to the use of cryotherapy and radiofrequency in the treatment of small renal tumours. These techniques will obviously have to stand the test of time.
- Published
- 2008
105. Ruptured aortic aneurysm masquerading as phlegmasia cerulea.
- Author
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Myers PO, Kalangos A, and Terraz S
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- Aged, Aortic Aneurysm, Abdominal diagnosis, Aortic Aneurysm, Abdominal surgery, Aortic Rupture diagnosis, Aortic Rupture surgery, Diagnostic Errors, Fatal Outcome, Humans, Male, Aortic Aneurysm, Abdominal physiopathology, Aortic Rupture physiopathology
- Abstract
Phlegmasia cerulea dolens, characterized by the triad of limb swelling, cyanosis, and acute ischemic pain, usually arises because of acute massive thrombosis of major deep, collateral, and superficial veins of an extremity. We report a patient with an atypically presenting ruptured aortic aneurysm masquerading as phlegmasia cerulea dolens. A 68-year-old man with a history of hypertension, intermittent claudication, and smoking presented with asthenia, macrohematuria, and mild back pain, as well as edema and blue mottling of the lower limbs and abdomen for 24 hours. The abdomen was nontender without a pulsatile mass or murmur. Computed tomography showed an 85-mm abdominal aortic aneurysm ruptured into the inferior vena cava. Phlegmasia cerulea dolens-like symptoms were explained by compromised venous outflow from the lower limbs because of an aortocaval fistula. The patient died of uncontrollable hemorrhage during emergent surgical repair. Three percent to 6% of patients with abdominal aortic aneurysm rupture present an aortocaval fistula, which can be suspected by the triad of abdominal or lower back pain, pulsatile abdominal mass, and machinery-type abdominal murmur. Left untreated, this condition rapidly leads to death from congestive heart failure. Only one third of patients are diagnosed before surgery because a fistula is often not suspected until unexplained massive hemorrhage occurs during the operation. Operative mortality is extremely high (34%). We propose that the clinical syndrome presented by our patient, a "blue fistula" frequently associated with aortocaval fistulae, be called phlegmasia cerulea non dolens, by analogy to Grégoire's "blue phlebitis."
- Published
- 2008
- Full Text
- View/download PDF
106. [Postpartum hemmorhage: prevention and treatment by arterial embolization and activated recombinant factor VII].
- Author
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Irion O, Terraz S, Boulvain M, Boehlen F, and Becker CD
- Subjects
- Arteries, Catheterization, Peripheral, Female, Fibrinogen therapeutic use, Hemostatic Techniques, Hemostatics therapeutic use, Humans, Labor Stage, Third drug effects, Oxytocics therapeutic use, Oxytocin therapeutic use, Patient Care Team, Postpartum Hemorrhage therapy, Pregnancy, Recombinant Proteins therapeutic use, Risk Factors, Uterine Contraction drug effects, Uterus blood supply, Coagulants therapeutic use, Embolization, Therapeutic methods, Factor VIIa therapeutic use, Postpartum Hemorrhage prevention & control
- Abstract
Primary postpartum hemorrhage occurs in 5% of deliveries and is source of serious maternal morbidity. Active management of third stage of labor with oxytocin administration reduces the risk by more than 60%. Hemorrhage is always underestimated. Teamwork with all involved caregivers is necessary. In case of failure or primary care, such as uterine massage, uterotonics and revision of uterus, cervix and vagina, two treatments must be offered to women: arterial embolization and activated recombinant factor VII. Embolization is effective in 75-100% of cases, thus avoiding hysterectomy. When possible, transfer to a center offering embolization shoud be decided early.
- Published
- 2008
107. Validation of fast MR thermometry at 1.5 T with gradient-echo echo planar imaging sequences: phantom and clinical feasibility studies.
- Author
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Cernicanu A, Lepetit-Coiffe M, Roland J, Becker CD, and Terraz S
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- Echo-Planar Imaging instrumentation, Feasibility Studies, Humans, Phantoms, Imaging, Reproducibility of Results, Sensitivity and Specificity, Thermography instrumentation, Body Temperature physiology, Echo-Planar Imaging methods, Image Interpretation, Computer-Assisted methods, Thermography methods
- Abstract
The purpose of this work was to validate in phantom studies and demonstrate the clinical feasibility of MR proton resonance frequency thermometry at 1.5 T with segmented gradient-echo echo planar imaging (GRE-EPI) sequences during liver tumour radiofrequency (RF) ablation. Classical GRE acquisitions and segmented GRE-EPI acquisitions were performed at 1.5 T during simultaneous RF heating with an MR-compatible RF electrode placed in an agar gel phantom. Temperature increments were calculated and compared with four optical temperature probe measurements using Bland- Altman analysis. In a preliminary clinical feasibility study, the rapid GRE-EPI sequence (echo train length = 13) was used for MR temperature monitoring of RF ablation of liver tumours in three patient procedures. For phantom experiments, the Bland-Altman mean of differences between MR and optical probe temperature measurements was <0.4 degrees C, and the 95% limits of agreement value was <1.4 degrees C. For the in vivo studies, respiratory-triggered GRE-EPI acquisitions yielded a temperature accuracy of 1.3 +/- 0.4 degrees C (acquisition time = 0.6 s/image, spatial coverage of three slices/respiratory cycle). MR proton resonance frequency thermometry at 1.5 T yields precise and accurate measurements of temperature increment with both classical GRE and rapid GRE-EPI sequences. Rapid GRE-EPI sequences minimize intra-scan motion effects and can be used for MR thermometry during RF ablation in moving organs., (Copyright (c) 2008 John Wiley & Sons, Ltd.)
- Published
- 2008
- Full Text
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108. [Complex liver resections: where are the limits?].
- Author
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Ris F, Majno P, Morel P, Terraz S, Andres A, and Mentha G
- Subjects
- Humans, Liver Neoplasms pathology, Hepatectomy methods, Liver Neoplasms surgery
- Abstract
Due to the progress in the management of liver cancer, the resection's limits have been pushed back and the concept of complex hepatectomy has become relevant. We identify five major factors affecting the complexity of hepatectomies. 3 with a direct effect on the peri-operative complications: 1) residual liver volume and quality; 2) the need of a vascular or biliary reconstruction and 3) the presence of co-morbidities. In addition to these factors, 2 major elements affect the long-term survival: 4) the extent of the tumoral disease and 5) the anatomical proximity of tumoral lesions to vascular or biliary structures. All these factors impact the ultimate outcome, requiring careful planning, operation and follow-up. This review summarizes the state of the art approach to complex hepatectomies.
- Published
- 2008
109. Percutaneous cryoablation of small kidney tumours under magnetic resonance imaging guidance: medium-term follow-up.
- Author
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Caviezel A, Terraz S, Schmidlin F, Becker C, and Iselin CE
- Subjects
- Adult, Aged, Aged, 80 and over, Angiomyolipoma pathology, Carcinoma, Renal Cell pathology, Creatinine blood, Female, Follow-Up Studies, Humans, Kidney Neoplasms pathology, Length of Stay, Male, Middle Aged, Neoplasm Staging, Tumor Burden, Angiomyolipoma surgery, Carcinoma, Renal Cell surgery, Cryosurgery methods, Kidney Neoplasms surgery, Magnetic Resonance Imaging methods, Minimally Invasive Surgical Procedures methods, Postoperative Complications blood, Surgery, Computer-Assisted methods
- Abstract
Objective: Minimally invasive treatment of small kidney tumours remains a challenge. Cryoablation has recently been advocated for such neoplasias. However, few series evaluating this therapeutic regimen are as yet available. The goal of this retrospective study was to evaluate the initial clinical experience of magnetic resonance imaging (MRI)-guided percutaneous cryotherapy of small renal tumours., Material and Methods: Seven patients with small renal tumours [mean diameter 21 (11-30) mm] underwent percutaneous renal tumour cryoablation using the Cryo-Hit delivery system. The procedure was performed in an MRI interventional unit, using a 0.23 Tesla open MRI imaging system. Five men and two women were included in the group. The average age was 61.5 (34-84) years. The patients had a solitary kidney (n = 2), renal insufficiency (n = 4) or a kidney graft (n = 1). The intervention was performed under general anaesthesia. Average time for the whole procedure was 235 min with 26 min of effective treatment time. Mean follow-up was 28 (7-43) months., Results: All tumours were successfully ablated. There were no perioperative complications. Mean hospital stay was 2.4 (2-5) days. One patient stayed for 5 days because therapeutic anticoagulation had to be reinitiated. No significant change in the perioperative value of the serum creatinine was noticed. No radiographic evidence of disease recurrence or new tumour development was identified during the follow-up., Conclusions: In this small group of patients, percutaneous renal tumour cryoablation under MRI guidance was efficient and carried no morbidity. Hospital stay was remarkably shorter than that of surgically treated patients. At medium-term follow-up, no recurrence has been identified, but long-term follow-up is required.
- Published
- 2008
- Full Text
- View/download PDF
110. 'Liver first' approach in the treatment of colorectal cancer with synchronous liver metastases.
- Author
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Mentha G, Roth AD, Terraz S, Giostra E, Gervaz P, Andres A, Morel P, Rubbia-Brandt L, and Majno PE
- Subjects
- Adult, Aged, Chemotherapy, Adjuvant, Colectomy methods, Colorectal Neoplasms mortality, Combined Modality Therapy, Female, Follow-Up Studies, Humans, Liver Neoplasms mortality, Male, Middle Aged, Neoplasm Staging, Pilot Projects, Prospective Studies, Risk Assessment, Survival Analysis, Time Factors, Treatment Outcome, Colorectal Neoplasms pathology, Colorectal Neoplasms therapy, Hepatectomy methods, Liver Neoplasms secondary, Liver Neoplasms therapy, Neoadjuvant Therapy
- Abstract
Background: In patients with synchronous colorectal liver metastases, an approach reversing the traditional therapeutic order - i.e. starting with chemotherapy first, doing the liver surgery second, and performing the colorectal surgery last - is theoretically appealing as it avoids the risk of metastatic progression during treatment of the primary tumor. The present series updates on a previously reported pilot experience., Patients and Methods: 35 patients with advanced synchronous colorectal metastases and nonobstructive colorectal tumors were treated with the reversed approach. Data were collected in a prospective database., Results: The median number of metastases was 6, the median size of the largest metastasis was 6 cm. Five patients could not complete the program (one death from sepsis during chemotherapy, 3 cases of progressive disease under treatment, and one case of vanishing liver metastases). The remaining 30 patients responded and underwent R0 liver resections with no major complications. One patient needed a Hartmann's procedure for obstruction after a first-step hepatectomy, and 1 patient had a rectal anastomotic leak. Median survival was 44 months. Overall survival rates of the 30 patients who completed the program at 1, 2, 3, 4 and 5 years were 100, 89, 60, 44 and 31%., Conclusions: The reverse approach appeared feasible and safe, with operability and survival rates better than expected for patients with similar severity. Potential problems, in particular regrowth of vanishing metastases and primary tumors, chemotherapy-associated liver damage, and large bowel obstruction, can be minimized by careful multidisciplinary selection, planning and execution., ((c) 2009 S. Karger AG, Basel.)
- Published
- 2008
- Full Text
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111. Improved long-term outcome of surgery for advanced colorectal liver metastases: reasons and implications for management on the basis of a severity score.
- Author
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Andres A, Majno PE, Morel P, Rubbia-Brandt L, Giostra E, Gervaz P, Terraz S, Allal AS, Roth AD, and Mentha G
- Subjects
- Adenocarcinoma mortality, Adenocarcinoma secondary, Adult, Aged, Aged, 80 and over, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Camptothecin administration & dosage, Camptothecin analogs & derivatives, Colorectal Neoplasms mortality, Colorectal Neoplasms pathology, Combined Modality Therapy, Female, Fluorouracil administration & dosage, Follow-Up Studies, Humans, Irinotecan, Liver Neoplasms mortality, Liver Neoplasms secondary, Male, Middle Aged, Neoadjuvant Therapy, Neoplasm Recurrence, Local surgery, Organoplatinum Compounds administration & dosage, Oxaliplatin, Postoperative Complications, Prospective Studies, Risk Factors, Survival Rate, Treatment Outcome, Adenocarcinoma surgery, Colorectal Neoplasms surgery, Hepatectomy, Liver Neoplasms surgery
- Abstract
Background: The outcome of liver resection for colorectal liver metastases (CRLM) appears to be improving despite the fact that surgery is offered to patients with more-severe disease. To quantify this assumption and to understand its causes we analyzed a series of patients on the basis of a standardized severity score and changes in management occurring over the years., Methods: Patients' characteristics, operative data, chemotherapies and follow-up were recorded. CRLM severity was quantified according to Fong's clinical risk score (CRS), modified to take into account the presence of bilateral liver metastases. Three periods were analyzed, in which different indications, surgical strategies and uses of chemotherapy were applied: 1984-1992, 1993-1998, and 1999-2005., Results: Between January 1984 and December 2005, 210 liver resections were performed in 180 patients (1984-1992, 43 patients; 1993-1998, 42 patients; 1999-2005, 95 patients). CRLM severity increased throughout the time periods, as did the use of neoadjuvant chemotherapies, repeat resections, and multistep procedures. While the disease-free survival did not improve over time, the 1-, 3- and 5-year overall survival rate increased from 85%, 30%, and 23% in the first period, to 88%, 60%, and 34% in the second period, and to 94%, 69%, and 46% in the third period., Conclusions: Analysis according to the CRS showed that despite the fact that patients had more severe disease, the overall survival improved over the years, mainly thanks to more aggressive treatment of recurrent disease. Management of advanced CRLM should, from the start, take into account the likelihood of secondary procedures.
- Published
- 2008
- Full Text
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112. New horizons in MR-controlled and monitored radiofrequency ablation of liver tumours.
- Author
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Cernicanu A, Lepetit-Coiffé M, Viallon M, Terraz S, and Becker CD
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- Animals, Catheter Ablation instrumentation, Catheter Ablation methods, Electrodes, Humans, Magnetic Resonance Imaging, Interventional instrumentation, Magnetic Resonance Imaging, Interventional methods, Thermography instrumentation, Thermography methods, Catheter Ablation trends, Liver Neoplasms surgery, Magnetic Resonance Imaging, Interventional trends
- Abstract
There is a sustained interest in using magnetic resonance (MR) thermometry to monitor the radiofrequency ablation of liver tumours as a means of visualizing the progress of the thermal coagulation and deciding the optimal end-point. Despite numerous technical challenges, important progress has been made and demonstrated in animal studies. In addition to MR thermometry, MR can now be used for the guidance of the tumour targeting with 'fluoroscopic' rapid image acquisition, and it can provide several contrast mechanisms for post-procedural assessment of the extent of the thermal coagulation zone. Challenges of in vivo simultaneous MR thermometry implementation and the current limitations of the thermal dose model for the estimation of the extent of the thermal coagulation zone are discussed. MR imaging could enhance the success of RF ablation of liver tumours due to its potential to provide accurate targeting, monitoring, and post-procedural evaluation.
- Published
- 2007
- Full Text
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113. Image-guided multipolar radiofrequency ablation of liver tumours: initial clinical results.
- Author
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Terraz S, Constantin C, Majno PE, Spahr L, Mentha G, and Becker CD
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- Adolescent, Adult, Aged, Aged, 80 and over, Contrast Media, Disease Progression, Female, Humans, Liver Neoplasms secondary, Male, Middle Aged, Neoplasm Recurrence, Local, Postoperative Complications, Statistics, Nonparametric, Survival Rate, Treatment Outcome, Carcinoma, Hepatocellular surgery, Catheter Ablation methods, Liver Neoplasms surgery, Magnetic Resonance Imaging, Interventional, Radiography, Interventional
- Abstract
The local effectiveness and clinical usefulness of multipolar radiofrequency (RF) ablation of liver tumours was evaluated. Sixty-eight image-guided RF sessions were performed using a multipolar device with bipolar electrodes in 53 patients. There were 45 hepatocellular carcinomas (HCC) and 42 metastases with a diameter < or =3 cm (n = 55), 3.1-5 cm (n = 29) and >5 cm (n = 3); 26 nodules were within 5 mm from large vessels. Local effectiveness and complications were evaluated after RF procedures. Mean follow-up was 17 +/- 10 months. Recurrence and survival rates were analysed by the Kaplan-Meier method. The primary and secondary technical effectiveness rate was 82% and 95%, respectively. The major and minor complication rate was 2.9%, respectively. The local tumour progression at 1- and 2-years was 5% and 9% for HCC nodules and 17% and 31% for metastases, respectively; four of 26 nodules (15%) close to vessels showed local progression. The survival at 1 year and 2 years was 97% and 90% for HCC and 84% and 68% for metastases, respectively. Multipolar RF technique creates ablation zones of adequate size and tailored shape and is effective to treat most liver tumours, including those close to major hepatic vessels.
- Published
- 2007
- Full Text
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114. Inadvertent fracture of a plastic biliary stent during a combined percutaneous-endoscopic procedure: a word of caution regarding self-locking pigtail biliary catheters.
- Author
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Dumonceau JM, Kahaleh M, and Terraz S
- Subjects
- Catheterization instrumentation, Cholangiography methods, Common Bile Duct diagnostic imaging, Device Removal adverse effects, Device Removal methods, Equipment Design adverse effects, Fatal Outcome, Foreign-Body Migration complications, Foreign-Body Migration diagnostic imaging, Humans, Liver diagnostic imaging, Male, Middle Aged, Pancreatitis complications, Catheterization adverse effects, Cholangiopancreatography, Endoscopic Retrograde adverse effects, Common Bile Duct surgery, Plastics adverse effects, Prosthesis Failure, Stents adverse effects
- Published
- 2007
- Full Text
- View/download PDF
115. Treatment of hepatocellular carcinoma at the dawn of the third millennium: liver transplantation and its alternatives.
- Author
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Majno P, Mentha G, Giostra E, Terraz S, Rubbia-Brandt L, Berney T, Buhler L, Toso Ch, Huber O, Spahr L, Morard I, Hadengue A, Becker Ch, Terrier F, and Morel P
- Subjects
- Carcinoma, Hepatocellular diagnosis, Carcinoma, Hepatocellular therapy, Humans, Liver Neoplasms diagnosis, Liver Neoplasms therapy, Mass Screening, Neoplasm Staging, Treatment Outcome, Carcinoma, Hepatocellular surgery, Liver Neoplasms surgery, Liver Transplantation
- Abstract
Hepatocellular carcinoma is one of the most frequent tumors worldwide, and its frequency is increasing. The management of hepatocellular carcinoma has changed in recent years, this because screening allows to discover tumors at an earlier stage, and because of effective treatments are available, such as liver transplantation, liver resection, percutaneous ablation and transarterial chemoembolization. Each one of these treatments has its own advantages and drawbacks, and range of application according to the stage of the tumor and of the underlying liver disease. This review summarizes the recent progress in the management of HCC and the practice in our unit.
- Published
- 2004
116. Percutaneous treatment of liver tumors with an adapted probe for cooled-tip, impedance-controlled radio-frequency ablation under open-magnet MR guidance: initial results.
- Author
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Kelekis AD, Terraz S, Roggan A, Terrier F, Majno P, Mentha G, Roth A, and Becker CD
- Subjects
- Adult, Aged, Artifacts, Carcinoma, Hepatocellular diagnosis, Carcinoma, Hepatocellular pathology, Colorectal Neoplasms diagnosis, Colorectal Neoplasms secondary, Colorectal Neoplasms surgery, Contrast Media, Electric Impedance, Electrocoagulation, Equipment Design, Female, Follow-Up Studies, Humans, Liver Neoplasms diagnosis, Liver Neoplasms pathology, Male, Necrosis, Neoplasm Recurrence, Local diagnosis, Neoplasm Recurrence, Local pathology, Neoplasm Recurrence, Local surgery, Tomography, X-Ray Computed, Treatment Outcome, Carcinoma, Hepatocellular surgery, Catheter Ablation instrumentation, Cold Temperature, Liver Neoplasms surgery, Magnetic Resonance Imaging methods, Surgery, Computer-Assisted
- Abstract
Percutaneous radio-frequency (RF) ablation of liver tumors is usually performed under guidance of real-time US, but some tumor nodules in some patients cannot be adequately visualized with this technique. We report our preliminary results with an MR-compatible, internally perfused 17-G RF probe adapted to a standard RF generator for impedance-controlled RF ablation under MR guidance. Following initial testing of the probe for MR compatibility, artifacts and macroscopic effects on an ex vivo pig liver, four patients with eight neoplastic liver nodules (five metastatic and three primary), which could not be properly targeted by US, were treated with the cooled-tip technique under MRI guidance in an open 0.23-T magnet. Metallic artifacts produced by the probe were useful for accurate placement and did not interfere with MRI monitoring at the end of the procedure. Based on imaging findings, the immediate result of RF was considered adequate in all instances. Local recurrence occurred in one instance after 6 months, requiring repeat treatment. No adverse effects were noted. Initial experience suggests that the probe we used allows to perform impedance-controlled cooled-tip RF ablation of liver tumors under open-magnet MR guidance.
- Published
- 2003
- Full Text
- View/download PDF
117. [Subarachnoid hemorrhage imaging].
- Author
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Rohmer P, Ben Bouzid H, Racle A, Steity JM, and Terraz S
- Subjects
- Humans, Magnetic Resonance Angiography, Magnetic Resonance Imaging, Subarachnoid Hemorrhage etiology, Subarachnoid Hemorrhage therapy, Subarachnoid Hemorrhage diagnosis
- Published
- 2000
118. Hypoxic contraction of small pulmonary arteries from normal and endotoxemic rats: fundamental role of NO.
- Author
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Terraz S, Baechtold F, Renard D, Barsi A, Rosselet A, Gnaegi A, Liaudet L, Lazor R, Haefliger JA, Schaad N, Perret C, Kucera P, Markert M, and Feihl F
- Subjects
- Animals, In Vitro Techniques, Lipopolysaccharides pharmacology, Male, Nitric Oxide Synthase metabolism, Nitric Oxide Synthase Type II, Pulmonary Artery drug effects, Pulmonary Artery enzymology, Rats, Rats, Wistar, Reference Values, Endotoxemia physiopathology, Hypoxia physiopathology, Nitric Oxide physiology, Pulmonary Artery physiopathology, Vasoconstriction physiology
- Abstract
The present study was aimed at examining the role of nitric oxide (NO) in the hypoxic contraction of isolated small pulmonary arteries (SPA) in the rat. Animals were treated with either saline (sham experiments) or Escherichia coli lipolysaccharide [LPS, to obtain expression of the inducible NO synthase (iNOS) in the lung] and killed 4 h later. SPA (300- to 600-micrometer outer diameter) were mounted as rings in organ chambers for the recording of isometric tension, precontracted with PGF2alpha, and exposed to either severe (bath PO2 8 +/- 3 mmHg) or milder (21 +/- 3 mmHg) hypoxia. In SPA from sham-treated rats, contractions elicited by severe hypoxia were completely suppressed by either endothelium removal or preincubation with an NOS inhibitor [NG-nitro-L-arginine methyl ester (L-NAME), 10(-3) M]. In SPA from LPS-treated rats, contractions elicited by severe hypoxia occurred irrespective of the presence or absence of endothelium and were largely suppressed by L-NAME. The milder hypoxia elicited no increase in vascular tone. These results indicate an essential role of NO in the hypoxic contractions of precontracted rat SPA. The endothelium independence of HPV in arteries from LPS-treated animals appears related to the extraendothelial expression of iNOS. The severe degree of hypoxia required to elicit any contraction is consistent with a mechanism of reduced NO production caused by a limited availability of O2 as a substrate for NOS.
- Published
- 1999
- Full Text
- View/download PDF
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