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Since the first U.S. endovascular aortic graft was performed, radiologists and physicians have learned a great deal about abdominal aortic aneurysms (AAA), endografts, and patient outcomes. This article presents critical information regarding aneurysm measurement, patient and device selection, device placement, management of endoleaks, and long-term patient outcome. [ABSTRACT FROM AUTHOR]

Study Objectives: Significant morbidity and mortality offset the benefits of lung volume reduction surgery (LVRS) for emphysema. By contributing to distal lung collapse, bronchoscopic placement of valved prostheses has the potential to noninvasively replicate the beneficial effects of LVRS. The purpose of this study was to investigate the safety and feasibility of placing valves in segmental airways of patients with emphysema.Design: Case series.Setting: Tertiary hospital, severe airways disease clinic.Patients: Ten patients aged 51 to 69 years with apical emphysema and hyperinflation, otherwise suitable for standard LVRS. Mean preoperative FEV(1) was 0.72 L (19 to 46% predicted), and 6-min walk distance was 340 m (range, 245 to 425 m).Intervention: Apical, bronchoscopic, segmental airway placement of one-way valves (silicone-based Nitinol bronchial stent; Emphasys Medical; Redwood City, CA) under general anesthesia. Placement was over a guidewire under bronchoscopic and fluoroscopic control.Results: Four to 11 prostheses per patient took 52 to 137 min to obstruct upper-lobe segments bilaterally. Inpatient stay was 1 to 8 days. No major complications were seen in the 30-day study period. Minor complications included exacerbation of COPD (n = 3), asymptomatic localized pneumothorax (n = 1), and lower-lobe pneumonia (day 37; n = 1). Symptomatic improvement was noted in four patients. No major change in radiologic findings, lung function, or 6-min walk distance was evident at 1 month, although gas transfer improved from 7.47 +/- 2.0 to 8.26 +/- 2.6 mL/min/mm Hg (p = 0.04) and nuclear upper-lobe perfusion fell from 32 +/- 10 to 27 +/- 9% (mean +/- SD) [p = 0.02].Conclusion: Bronchoscopic prostheses can be safely and reliably placed into the human lung. Further study is needed to explore patient characteristics that determine symptomatic efficacy in a larger patient cohort. [ABSTRACT FROM AUTHOR]

1 Chlormethiazole was used as a basal sedative for patients undergoing angiographic procedures. 2 Blood samples were drawn opportunistically to examine chlormethiazole extraction across liver, lungs and kidney. 3 Extraction across liver was typically 70-80% and apparently unrelated to input concentrations. Evidence for extraction across lung and kidney was inconclusive but these could each be approximately 20%. 4 Pharmacokinetics of chlormethiazole derived from compartment models were in accord with previous reports and were characterised by a high total body clearance (1-1.5 l/min). 5 Postural changes associated with the radiological procedures caused fluctuating blood concentrations which appear as noise in curve fitting procedures. 6 Pharmacokinetic properties derived from compartment theory cannot cope with these perturbations because of the restriction imposed by time averaging (i.e. mean clearances, half-lives and volumes are produced). Systematic studies of pharmacokinetic properties of perfusion-limited drugs such as chlormethiazole must be developed in such a way as to allow for independent variation of flow and extraction. [ABSTRACT FROM AUTHOR]

Spontaneous nonhemophiliac hemarthrosis is an unusual entity, which has been little described. We present three cases of spontaneous recurrent hemarthrosis post total knee replacement (TKR) and successful management with embolization. Three male patients were referred to our service for angiography and treatment of recurrent hemarthrosis post TKR. In all three patients antegrade ipsilateral common femoral artery punctures and selective angiography of the geniculate branches were performed with a microcatheter. Abnormal vasculature was noted in all cases. Subsequent embolization was performed with Contour (Boston Scientific, Target Vascular, Cork, Ireland) embolization particles (150-250 and 250-355 microm) in two patients and microcoils in the third (TornadoR; Cook Inc., Bloomington, IN, USA). Technical success was 100%. One patient had a recurrence of symptoms requiring a repeat procedure 6 months later. No complications were encountered. Selective angiography and particle embolization is an effective technique for management of this unusual but problematic postoperative sequelae. [ABSTRACT FROM AUTHOR]

Introduction: To evaluate a radiographer-led peripherally inserted central catheter (PICC) insertion service within an interventional radiology suite using ultrasound and fluoroscopic guidance., Methods: Data from 366 consecutive PICC insertions by five trained angiography-specialized radiographers were prospectively collected over a 12-month period. For each PICC insertion, patient demographics, including past medical history of cystic fibrosis (CF), number of punctures, vein used, final tip position, contrast administration and screening time were recorded. Institutional review board approval was obtained., Results: The overall PICC insertion success rate was 100%. Fifty-five (15%) had a known medical history of CF. Three hundred and thirty-one (90%) PICC insertions required a single puncture and 32 (9%) required two punctures. The remaining three insertions required three punctures. The basilic vein was most commonly used (69%) followed by the brachial vein (29%), and the cephalic vein was used only in 2%. Administration of contrast medium was necessary during 27 (7%) PICC insertions. Mean screening time was 10.7 s., Conclusion: Our specifically trained, radiographer-led PICC insertion service proved to be successful. Both straightforward and complex insertions, for example in CF patients could be adequately and efficiently performed., (© 2020 The Royal Australian and New Zealand College of Radiologists.)

Purpose: This study examined the effectiveness of a formal postdoctoral education program designed to teach skills in clinical and translational science, using scholar publication rates as a measure of research productivity., Method: Participants included 70 clinical fellows who were admitted to a master's or certificate training program in clinical and translational science from 1999 to 2015 and 70 matched control peers. The primary outcomes were the number of publications 5 years post-fellowship matriculation and time to publishing 15 peer-reviewed manuscripts post-matriculation., Results: Clinical and translational science program graduates published significantly more peer-reviewed manuscripts at 5 years post-matriculation (median 8 vs 5, p =0.041) and had a faster time to publication of 15 peer-reviewed manuscripts (matched hazard ratio = 2.91, p =0.002). Additionally, program graduates' publications yielded a significantly higher average H-index (11 vs. 7, p =0.013)., Conclusion: These findings support the effectiveness of formal training programs in clinical and translational science by increasing academic productivity.

Purpose: To develop and validate a perfused organ model for characterizing ablations for irreversible electroporation (IRE)-based therapies., Materials and Methods: Eight excised porcine livers were mechanically perfused with a modified phosphate-buffered saline solution to maintain viability during IRE ablation. IRE pulses were delivered using 2 monopolar electrodes over a range of parameters, including voltage (1,875-3,000 V), pulse length (70-100 µsec), number of pulses (50-600), electrode exposure (1.0-2.0 cm), and electrode spacing (1.5-2.0 cm). Organs were dissected, and treatment zones were stained with triphenyl tetrazolium chloride to demonstrate viability and highlight the area of ablation. Results were compared with 17 in vivo ablations performed in canine livers and 35 previously published ablations performed in porcine livers., Results: Ablation dimensions in the perfused model correlated well with corresponding in vivo ablations (R 2 = 0.9098) with a 95% confidence interval of < 2.2 mm. Additionally, the validated perfused model showed that the IRE ablation zone grew logarithmically with increasing pulse numbers, showing small difference in ablation size over 200-600 pulses (3.2 mm ± 3.8 width and 5.2 mm ± 3.9 height)., Conclusions: The perfused organ model provides an alternative to animal trials for investigation of IRE treatments. It may have an important role in the future development of new devices, algorithms, and techniques for this therapy., (Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.)

Preterm birth occurs in 10% of pregnancies and is a major cause of neonatal morbidity and mortality. The majority of cases of early preterm labour are associated with infection/inflammation, which places the fetal central nervous system at risk. Targeting immune activation is therefore an appealing therapeutic strategy for the prevention of preterm labour and neonatal brain injury. The expression of many labour-associated and inflammatory-response genes is controlled by the transcription factors nuclear factor-κB (NF-κB) and activator protein-1 (AP-1), which makes them therapeutic targets of interest. Sulfasalazine (SASP) has been shown to inhibit NF-κB and reduce lipopolysaccharide-induced cytokine concentrations in fetal membrane explants and reduce the rate of Escherichia coli-induced preterm labour in mice. Its effects upon AP-1 in the context of pregnancy are unknown. In this study the effect of SASP on interleukin-1β (IL-1β) -induced NF-κB and AP-1 activity, cytokine production and cyclo-oxygenase-2 (COX-2) expression was examined in amniocytes and myocytes. A supra-therapeutic concentration (5 mm) was required to inhibit IL-1β-induced NF-κB (P < 0·0001) in amniocytes and IL-1β-induced NF-κB (P < 0·01), AP-1 (P < 0·01) and COX-2 (P < 0·05) in myocytes. Despite inhibiting IL-1β-induced cytokines, a basal increase in IL-6 (P < 0·01), IL-8 (P < 0·0001) and tumour necrosis factor-α (TNF-α) (P < 0·001) was seen with 5 mm SASP in amniocytes, and significant cytotoxic effects were seen in myocytes. The therapeutic concentration of 0·015 mm had no inhibitory effects on pro-inflammatory mediators, but led to an augmented response to IL-1β-induced IL-6 (P < 0·01), IL-8 (P < 0·05) and TNF-α (P < 0·05) in amniocytes and IL-8 (P < 0·05) in myocytes. SASP is therefore an unlikely therapeutic candidate for the prevention of inflammation-induced preterm labour., (© 2015 John Wiley & Sons Ltd.)

Irreversible electroporation (IRE) is a novel nonthermal focal ablation technique that uses a series of brief but intense electric pulses delivered by paired electrodes into a targeted region of tissue, killing the cells by irreversibly disrupting cellular membrane integrity. Unlike other ablation methods, IRE has relatively little effect on connective tissues and nerves and has a low patient effect. The ability of IRE to achieve cell death immediately adjacent to large vessels without effect on the vessels themselves has raised the possibility of better treatment of advanced pancreatic cancer. Because of the low effect on the patient, IRE is well suited for use in conjunction with chemotherapeutic agents. The IRE effect is not uniform and is dependent on the intrinsic conductivity of the tissue, the number of pulses delivered, the current flow achieved, and the total time for the treatment. It is currently under investigation for a wide range of solid tumors and prostate cancer in humans and in animals in the breast, brain, and spinal cord. In clinical practice, IRE can be administered either percutaneously under imaging guidance or at open operation under direct vision. In animals there is some evidence of an immune response presumably due to exposure of the intracellular target material, resulting in a greater therapeutic effect. Unlike many other cancer treatments, IRE has been introduced for human clinical use at a very early stage of development of the technique and much of the basic understanding of how and when to use IRE is still under investigation., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Introduction: Irreversible electroporation (IRE) ablation uses a series of brief electric pulses to create nanoscale defects in cell membranes, killing the cells. It has shown promise in numerous soft-tissue tumor applications. Larger voltages between electrodes will increase ablation volume, but exceeding electrical limits may risk damage to the patient, cause ineffective therapy delivery, or require generator restart. Monitoring electrical current for these conditions in real-time enables managing these risks. This capacity is not presently available in clinical IRE generators., Methods: We describe a system using a Tektronix TCP305 AC/DC Current Probe connected to a TCPA300 AC/DC Current Probe Amplifier, which is read on a computer using a Protek DSO-2090 USB computer-interfacing oscilloscope. Accuracy of the system was tested with a resistor circuit and by comparing measured currents with final outputs from the NanoKnife clinical electroporation pulse generator., Results: Accuracy of measured currents was 1.64 ± 2.4 % relative to calculations for the resistor circuit and averaged 0.371 ± 0.977 % deviation from the NanoKnife. During clinical pulse delivery, the system offers real-time evaluation of IRE procedure progress and enables a number of methods for identifying approaching issues from electrical behavior of therapy delivery, facilitating protocol changes before encountering therapy delivery issues., Conclusions: This system can monitor electrical currents in real-time without altering the electric pulses or modifying the pulse generator. This facilitates delivering electric pulse protocols that remain within the optimal range of electrical currents-sufficient strength for clinically relevant ablation volumes, without the risk of exceeding safe electric currents or causing inadequate ablation.

Irreversible electroporation (IRE) ablation uses brief electric pulses to kill a volume of tissue without damaging the structures contraindicated for surgical resection or thermal ablation, including blood vessels and ureters. IRE offers a targeted nephron-sparing approach for treating kidney tumors, but the relevant organ-specific electrical properties and cellular susceptibility to IRE electric pulses remain to be characterized. Here, a pulse protocol of 100 electric pulses, each 100 μs long, is delivered at 1 pulse/s to canine kidneys at three different voltage-to-distance ratios while measuring intrapulse current, completed 6 h before humane euthanasia. Numerical models were correlated with lesions and electrical measurements to determine electrical conductivity behavior and lethal electric field threshold. Three methods for modeling tissue response to the pulses were investigated (static, linear dynamic, and asymmetrical sigmoid dynamic), where the asymmetrical sigmoid dynamic conductivity function most accurately and precisely matched lesion dimensions, with a lethal electric field threshold of 575 ± 67 V/cm for the protocols used. The linear dynamic model also attains accurate predictions with a simpler function. These findings can aid renal IRE treatment planning under varying electrode geometries and pulse strengths. Histology showed a wholly necrotic core lesion at the highest electric fields, surrounded by a transitional perimeter of differential tissue viability dependent on renal structure.

Purpose: To evaluate the analgesic efficacy of oral premedication of oxycodone in a group of patients undergoing elective uterine artery embolization under sedation for fibroid disease., Methods: Thirty-nine patients (mean age 42.3 years) were prospectively randomized 1:1 to receive 20 mg oxycodone or placebo orally immediately before their procedure. At the commencement of the procedure, patients were provided with a patient-controlled analgesia device for 24 h, programmed to deliver 1 mg boluses of intravenous morphine with a 5 min lockout. Mean visual analog scale pain intensity ratings (0-100 mm) were measured from both groups and evaluated over 0 to 6 h as the primary end point. Other measured parameters included opioid-related side effects and eligibility for discharge (NCT00163930; September 12, 2005)., Results: Early pain intensity did not vary significantly between the active and placebo groups [mean (standard deviation): 3.2 (2.5) vs. 3.1 (2.2), p = 0.89]. The oxycodone group, however, experienced significantly more nausea (p = 0.035) and a greater incidence of vomiting (p = 0.044). Overall opioid requirement over 24 h, measured as oral morphine equivalent, was greater in the oxycodone group (median [interquartile range]: 64.5 [45-90] mg vs. 22.5 [15-46.5] mg, p < 0.0001). The number of patients first eligible for discharge at 24 h in the oxycodone group was decreased but not significantly (p = 0.07)., Conclusion: The addition of preprocedural oral oxycodone to morphine patient-controlled analgesia does not offer any analgesic advantage to patients having uterine artery embolization and may cause a greater incidence of nausea and vomiting.

Background: Irreversible electroporation (IRE) delivers brief electric pulses to attain non-thermal focal ablation that spares vasculature and other sensitive systems. It is a promising prostate cancer treatment due to sparing of the tissues associated with morbidity risk from conventional therapies. IRE effects depend on electric field strength and tissue properties. These characteristics are organ-dependent, affecting IRE treatment outcomes. This study characterizes the relevant properties to improve treatment planning and outcome predictions for IRE prostate cancer treatment., Methods: Clinically relevant IRE pulse protocols were delivered to a healthy canine and two human cancerous prostates while measuring electrical parameters to determine tissue characteristics for predictive treatment simulations. Prostates were resected 5 hr, 3 weeks, and 4 weeks post-IRE. Lesions were correlated with numerical simulations to determine an effective prostate lethal IRE electric field threshold., Results: Lesions were produced in all subjects. Tissue electrical conductivity increased from 0.284 to 0.927 S/m due to IRE pulses. Numerical simulations show an average effective prostate electric field threshold of 1072 ± 119 V/cm, significantly higher than previously characterized tissues. Histological findings in the human cases show instances of complete tissue necrosis centrally with variable tissue effects beyond the margin., Conclusions: Preliminary experimental IRE trials safely ablated healthy canine and cancerous human prostates, as examined in the short- and medium-term. IRE-relevant prostate properties are now experimentally and numerically defined. Importantly, the electric field required to kill healthy prostate tissue is substantially higher than previously characterized tissues. These findings can be applied to optimize IRE prostate cancer treatment protocols., (© 2014 Wiley Periodicals, Inc.)

Purpose: Electroporation-based therapies deliver brief electric pulses into a targeted volume to destabilize cellular membranes. Nonthermal irreversible electroporation (IRE) provides focal ablation with effects dependent on the electric field distribution, which changes in heterogeneous environments. It should be determined if highly conductive metallic implants in targeted regions, such as radiotherapy brachytherapy seeds in prostate tissue, will alter treatment outcomes. Theoretical and experimental models determine the impact of prostate brachytherapy seeds on IRE treatments., Materials and Methods: This study delivered IRE pulses in nonanimal, as well as in ex vivo and in vivo tissue, with and in the absence of expired radiotherapy seeds. Electrical current was measured and lesion dimensions were examined macroscopically and with magnetic resonance imaging. Finite-element treatment simulations predicted the effects of brachytherapy seeds in the targeted region on electrical current, electric field, and temperature distributions., Results: There was no significant difference in electrical behavior in tissue containing a grid of expired radiotherapy seeds relative to those without seeds for nonanimal, ex vivo, and in vivo experiments (all p > 0.1). Numerical simulations predict no significant alteration of electric field or thermal effects (all p > 0.1). Histology showed cellular necrosis in the region near the electrodes and seeds within the ablation region; however, there were no seeds beyond the ablation margins., Conclusion: This study suggests that electroporation therapies can be implemented in regions containing small metallic implants without significant changes to electrical and thermal effects relative to use in tissue without the implants. This supports the ability to use IRE as a salvage therapy option for brachytherapy.

The aims of this study were to evaluate the safety, feasibility and tumour response of &#95;irreversible electroporation, a non-thermal ablation technique, for the treatment of unresectable hepatocellular carcinoma. The endpoints were safety and local treatment efficacy. Patients with unresectable tumours and tumours not amenable for radiofrequency &#95;ablation because of their vicinity to organs vulnerable to thermal damage such as the bowel or because they were close to large blood vessels that would limit efficacy of ablation due to the heat sink effect were treated with irreversible electroporation using percutaneous &#95;ultrasound and/or computed tomography guided electrode placement between November 2008 and &#95;December 2009. Early, late, minor and major complications were recorded. Tumour response was determined on triphasic helical computed tomography follow-up at one month, then every three months post-procedure. Eleven patients received IRE therapy to 18 HCC lesions (Mean diameter 2.44 ± 0.99 cm; range 1.0-6.1 cm) with five patients having more than one treated HCC. Mean follow-up was 18 months (range 14-24 months). Six patients required repeat treatments for local residual or recurrent disease; two of these also had IRE for distant intrahepatic recurrence. No serious complications were observed despite seven lesions lying adjacent to important structures or organs. Four patients developed transient urinary retention and seven developed transient local post-procedure pain. After IRE therapy, 13 (72%) lesions were completely ablated with 93% success for lesions ≤ 3 cm (13/14). The local recurrence-free period was 18 ± 4 months and the distance recurrence free period was 14 ± 6 months. These preliminary results suggest that IRE is a safe and feasible technique for local ablation of HCC, particularly for lesions less than 3 cm. No major complications were encountered during this study even for tumours close to essential structures or organs.

Purpose: A single-center prospective nonrandomized cohort study was performed to investigate the safety of irreversible electroporation (IRE) for tumor ablation in humans., Materials and Methods: Thirty-eight volunteers with advanced malignancy of the liver, kidney, or lung (69 separate tumors) unresponsive to alternative treatment were subjected to IRE under general anesthesia. Clinical examination, biochemistry, and computed tomography (CT) scans of the treated organ were performed before, immediately after, and at 1 month and 3 months after the procedure., Results: No mortalities occurred at 30 days. Transient ventricular arrhythmia occurred in four patients, and electrocardiographically (ECG) synchronized delivery was used subsequently in the remaining 30 patients, with two further arrhythmias (supraventricular tachycardia and atrial fibrillation). One patient developed obstruction of the upper ureter after IRE. One adrenal gland was unintentionally directly electroporated, which produced transient severe hypertension. There was no other evidence of adjacent organ damage related to the electroporation. Other adverse events were not directly related to IRE, but two patients developed temporary neurapraxia as a result of arm extension during a prolonged period of anesthesia. Although not a primary aim of this preliminary study, complete target tumor ablation verified by CT was achieved in 46 of the 69 tumors treated with IRE (66%). Most treatment failures occurred in renal and lung tumors. Biopsy in three patients showed coagulative necrosis in the regions treated by IRE., Conclusions: IRE appears to be safe for human clinical use provided ECG-synchronized delivery is used. Comparative evaluation with alternative ablative technologies is warranted., (Copyright © 2011 SIR. Published by Elsevier Inc. All rights reserved.)

Unlabelled: Recruitment maneuvers (RMs) can expand collapsed alveoli in ventilated patients. The optimal method for delivering RMs is unknown., Purpose: To evaluate the safety and the respiratory and hemodynamic effects of a staircase recruitment maneuver (SRM) with decremental positive end expiratory pressure (PEEP) titration and the consequences of desaturation during the SRM in patients with early acute lung injury (ALI)., Methods: In total, 20 consecutive patients with early ALI were enrolled and received an SRM. Patients were given 15 ± 3 cm H(2)O pressure-controlled ventilation. Positive end expiratory pressure was increased from baseline (range 10-18) to 20, 30, and 40 cm H(2)O every 2 minutes to achieve maximum alveolar pressure of 55 ± 3 cm H(2)O, then decreased at 3-minute intervals to 25, 22.5, 20, 17.5, and 15 cm H(2)O until a decrease of 1% to 2% oxygen saturation from maximum was detected. Positive end expiratory pressure was left at the level where the fall in oxygen saturation occurred. Standard respiratory and circulatory variables, arterial and central venous gases were measured before, during, and after the SRM., Results: There were significant improvements in shunt fraction (36.3% ± 10% to 26.4% ± 14%, P < .001), oxygen saturation (93.4% ± 2% to 96.8% ± 3%, P = .007), partial pressure of oxygen, arterial (PaO(2))/fraction of inspired oxygen ([FIO(2)]; 150 ± 42 to 227 ± 100, P = .004), lung compliance (33.9 ± 9.1 to 40.1 ± 11.4 mL/cm H(2)O, P < .01), and chest x-ray (CXR) after the SRM. Briefly, 80% of the patients responded and the response was maintained at 1 hour. In total, 8 patients desaturated 6.1% ± 2.8% in SaO(2) during the SRM but 5 of those improved SaO(2) relative to baseline by the end of the SRM., Conclusions: In all, 80% of the patients with early ALI responded to the SRM with decremental PEEP titration. Desaturation during the SRM did not indicate a failed response 1 hour later.

Background: Bioelectrics, an interesting new area of medicine, combines pulsed high-voltage engineering with cell biology and has many potential applications. Pulsed electric current can be used to produce irreversible electroporation (IRE) of cell membranes with resulting cell death. This process has been shown to ablate tumors in animal studies., Methods: A clinical trial of IRE as a tumor ablation therapy was performed at our institution. A pulsating direct current of 20 to 50 A and 500 to 3000 V was delivered into metastatic or primary tumors in the liver, kidney, or lung via needle electrodes inserted under computed tomography (CT) or ultrasound guidance. Patients required a relaxant general anesthetic. We describe some challenges presented to anesthesiologists. Guidelines for anesthesia were produced and modified as issues became apparent. The patients' charts were audited throughout., Results: We noted a number of issues. The electrical discharge produced generalized upper body muscular contractions requiring neuromuscular blockade. Two patients developed positional neuropraxia because of the extended arm position requested for CT scanning. After experimentation, we have developed a modified arm position. Some patients developed self-limiting ventricular tachycardias that are now minimized by using an electrocardiogram synchronizer. Three patients developed pneumothoraces as a result of the needle electrode insertion., Conclusions: Relaxant general anesthesia is required for IRE of the liver, lung, and kidney. An electrocardiogram synchronizer should be used to minimize the risk of arrhythmias. Attention to the position of the arms is required to maximize CT scan quality but minimize brachial plexus strain. Simple postoperative analgesia is all that is required in most patients.

In an emergency department (ED), computed tomography (CT) is particularly beneficial in the investigation of high-speed trauma patients. With the advent of multidetector CT (MDCT) scanners, it is becoming faster and easier to conduct scans. In recent years, this has become evident with an increasing number of CT requests. Patients who have multiple CT scans during their hospital stay can receive radiation doses that have an increased theoretical risk of induction of cancer. It is essential that the clinical justification for each CT scan be considered on an individual basis and that due consideration is given to the radiation risk and possible diagnostic benefit. The current lack of a central State or Commonwealth data repository for medical images is a contributing factor to excessive radiation dosage to the population. The principles of justification and radiation risks are discussed in this study.

Percutaneous radiofrequency (RF) ablation is a promising treatment for solid renal tumors in selected patients. Nontarget thermal damage is a known risk of the procedure. The authors describe a case of a patient who underwent RF ablation of a lower pole renal lesion and subsequently developed a ureteric stricture secondary to thermal injury. Successful management of the ureteric stricture required a rendezvous procedure. This report illustrates the potential complication of ureteric stricture formation after a RF ablation procedure and the management challenges posed by such thermal injuries.

A coronary artery fistula is a rare cause of cardiac symptoms or signs in an adult. We report here the successful percutaneous treatment of a large fistula in an adult who had suffered an acute myocardial infarction peri-operatively due to a steal phenomenon. Due to the fistula size, a specially constructed occlusion device was utilised for effective treatment.

Objective: This study evaluated the ability of a fast spin echo T2 weighted dark blood sequence to characterize significant (>50%) renal artery stenosis compared to conventional angiography., Methods: Sixteen patients underwent conventional catheter angiography for either renal artery stenosis evaluation or as potential renal donors. Each patient then had an MR study of the renal arteries and kidneys with fast spin echo T2 weighted MR (TR 4000, TE 102, 8 echo train length) on a Superconducting 1.5T Magnet. Results were compared with angiography and inter and intra observer statistics were calculated., Results: A total of 36 renal arteries were imaged in 32 kidneys with 12 stenoses >50%. Fast spin echo T2 weighted MR is 94% accurate (95%CI: 87-100%) in detection of significant renal artery stenosis. Dark blood MRA (DBMRA) is 96% sensitive (95%CI: 89-100), 92% specific, with a predictive value positive of 96% for classifying real arteries as normal or significantly stenosed. Inter and intra observer statistics demonstrate good to excellent agreement in renal artery classification (kappa>0.60)., Conclusion: DBMRA may be a useful adjunct to renal MR evaluation in hypertension., Summary: A total of 36 renal arteries were imaged in 32 kidneys with 12 stenoses >50%. Fast spin echo T2 weighted MR is 94% accurate (95%CI: 87-100%) in detection of significant renal artery stenosis.

Background: Renal artery stenosis is increasingly being treated with the percutaneous insertion of stents. Little data are available to help select patients most likely to derive benefit from the procedure., Methods: Data were gathered on all patients treated with renal artery stent insertion at the Royal Melbourne Hospital prior to 1998, and who were followed-up for at least 6 months or until death. Multivariate regression analysis was used to identify factors associated with patient survival and renal survival (survival free of dialysis)., Results: Adequate data were available on 148 of 198 patients treated during this time (75%). A baseline creatinine over 0.15 mmol/L and age over 70 were strongly associated with worse patient survival (Likelihood ratio(LR) 9.96, p < 0.0001 and 3.4, p = 0.001 respectively) and renal survival (LR 7.8, p < 0.001 and 2.7, p < 0.01 respectively). The presence of diabetes was also associated with worse overall survival (LR 2.2, p < 0.05) but not renal survival, while the presence of another nephropathic disorder was associated with worse renal survival (LR 2.8, p < 0.01) but not overall survival. The use of ACE inhibitors after the stenting procedure was associated with a significantly better renal survival (LR 0.46, p < 0.05)., Conclusions: Patients with baseline renal impairment, older age, diabetes or another coexistent renal disease have poor outcomes after renal artery stent insertion. A relatively conservative approach to revascularisation may be preferable in these patient groups. The use of ACE inhibitors after stent insertion is associated with a reduced likelihood of death or dialysis.

Objective: To determine by cerebral venography and manometry in patients with idiopathic intracranial hypertension the cause of the previously demonstrated venous hypertension in the superior sagittal and proximal transverse sinuses., Methods: Cerebral venous sinus pressure was measured before and immediately after C1-2 puncture with removal of 20 to 25 mL of CSF., Results: Lowering the intracranial pressure by lateral C1-2 puncture during manometry has shown that the venous hypertension resolves immediately., Conclusion: These studies indicate that the venous hypertension is due to compression of the transverse sinuses by raised intracranial pressure and not due to a primary obstructive process in the cerebral venous sinuses.

Renal artery stenosis is a common, progressive cause of hypertension and renal impairment, and is frequently treated with percutaneous transluminal dilatation and stenting. The outcome of this procedure is still being evaluated. The records of 198 consecutive patients who had stents inserted at the Royal Melbourne Hospital were analysed retrospectively, and adequate follow-up information on 148 (75%), in whom a total of 182 renal arteries had been treated was obtained. Technical success was achieved in 144 patients (97%). Complications occurred in 19 patients (13.3%), with major complications occurring in 10 (7.0%) and one death occurring in relation to the procedure. A fall in average systolic blood pressure of 13.2 mmHg (12.1-14.3 mmHg) was seen and a fall in diastolic blood pressure of 10.1 mmHg (9.3-10.9 mmHg), without an increase in the number of antihypertensive drugs used. Renal function remained stable in the majority of patients, particularly those who had minimal baseline renal impairment. Restenosis was common after 6 months, occurring eventually in 29% of screened patients, but was not shown to affect clinical outcomes. Insertion of renal artery stents is a safe and effective treatment for renal artery stenosis.

A case series is presented demonstrating a unique approach to the treatment of tandem atherosclerotic lesions of the internal carotid artery. Between 1994 and 1999 eight patients with tandem lesions of the internal carotid artery were treated by combined carotid endarterectomy for the proximal lesion and intraoperative angioplasty of the distal intracranial lesion via the carotid arteriotomy. The success and complication rates were evaluated. A 100% technical success rate was achieved with one post procedural complication by ipsilateral stroke within 24 h. The advantages of this technique include the treatment of tandem lesions by the one procedure, improved transluminal access to the intracranial lesion and the ability to reduce the risk of embolism by flow control during balloon inflation.

Objective: Prior studies have shown that renal MR contrast enhancement improves the efficacy of mass and proximal vascular evaluation. This study assessed the usefulness of different sequences for characterization of masses that appeared suspicious on CT and for prediction of their potential for malignancy., Subjects and Methods: In a prospective manner 32 patients (age range, 26-78 years: average age, 54 years), each with at least one suspicious mass on CT, were examined with MR imaging. The following sequences were performed: conventional spin-echo with and without fat saturation, fast spin-echo, and dynamic gadopentetate dimeglumine-enhanced infusion using a 1.5-T superconducting magnet. Results were analyzed and compared with pathologic results after resection., Results: A total of 65 renal masses of average size 2.6 cm (range, 1-10 cm) were detected with dynamic MR imaging. Seventeen of the 65 masses were malignant. Of the 17 malignant masses, three did not enhance on dynamic MR imaging (because of hemorrhage). Sixteen of the 17 malignant masses were heterogeneous on T2-weighted images. Three enhancing masses contained fat and all were angiomyolipomas. Thirty-five of the 65 masses (four with hemorrhage) did not show enhancement, all of which were homogeneous on T2-weighted images and were proven to be cysts. Five masses resulted from infections and had heterogeneous T2 appearance. The remaining masses were three hematomas with hemorrhage, one column of Bertin, and one aneurysm., Conclusion: Renal masses that are interpreted as suspicious on CT may lack MR enhancement because of hemorrhage effects; heterogeneity of their T2 appearance is thus critical in differentiating malignancy from benign disease. Odds-ratio calculations give an adjusted estimate of a 3.36-fold increase (95% confidence interval, 1.8-6.27) in the likelihood of malignancy when masses are heterogeneous on T2-weighted images and a 29-fold increase (95% confidence interval, 3.67-241.8) for predicting malignancy when enhancement is present.

The purpose of the present paper was to assess whether conventional renal Doppler ultrasound and the commonly used parameters of peak systolic velocity and renal aortic ratio may be an appropriate modality for the follow-up of renal artery stents. A total of 19 arteries in 15 patients was examined with both renal Doppler ultrasound and angiography for the presence or absence of recurrent renal artery stenosis. Disease was considered present on angiography if the arterial diameter was more than 60% stenotic. Doppler criteria for stenosis were either a peak systolic velocity of > 180 cm/s or a renal aortic ratio of > 3.0. Echo enhancement with Levovist (Schering, Berlin, Germany) was used if studies were technically unsuccessful or to improve diagnostic confidence. Renal Doppler ultrasound detected 100% of renal artery stenoses. The specificity was 75%, the positive predictive value was 67% and the negative predictive value was 100%. Echo enhancement improved the technical success rate from 89 to 95% and also increased diagnostic confidence in six examinations. The present limited study suggests that similar renal Doppler parameters as used for the study of unstented renal arteries may be applied to the examination of renal arteries with renal stents in situ. It therefore suggests that Doppler ultrasound may provide an adequate non-invasive means of renal artery stent follow-up, particularly when combined with echo-enhancing agents. Further study is warranted to confirm these initial conclusions.

Purpose: To assess, in a multicenter setting, safety, technical results, and restenosis rate of the Palmaz stent for treatment of atherosclerotic ostial renal artery stenosis., Methods: Ten centers enrolled 106 patients (120 treated renal artery stenoses) in the study. Patient selection was based on unsuccessful percutaneous transluminal renal angioplasty (residual stenosis >/= 20%) performed for treatment of ostial stenosis >/= 50%, in patients with hypertension and/or impaired renal function. Safety was assessed by means of the complication rate, and technical results by the number of successful stent placements and occurrence of restenosis (>50%) at intraarterial angiographic follow-up., Results: Stent placement was successful (n = 112) or partially successful (n = 5) in 117 (98%) arteries. Complications occurred in 19 procedures; seven were of serious clinical significance. Angiographic follow-up was performed in 89 of 117 (76%) cases, at a mean of 8 months (range 2. 5-18 months). Fifteen stents (16.9%) showed restenosis (at a mean of 8.5 months), of which 10 were successfully redilated., Conclusion: Renal artery stenting has a high technical success rate, a complication rate comparable to percutaneous transluminal renal angioplasty, and a low rate of restenosis at 8 months angiographic follow-up.

Magnetic resonance contrast enhancement depends on the relative timing of image acquisition. Limited human trials have demonstrated efficacy of intra-arterial gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) in delineating vascular anatomy with X-rays. The present study assessed the ability of dynamic MR during intra-arterial Gd-DTPA administration to demonstrate vascular anatomy compared to conventional angiography as the gold standard. As interventional MR techniques using dedicated magnets proliferate, the ability to perform invasive MR angiography with a conventional magnet would be of great utility at established sites. Four subjects referred for different types of angiography underwent dynamic MR studies, including one with iliac artery stenting (Palmaz P204, Johnson and Johnson). All were examined with conventional angiography, and again after dynamic intra-arterial (IA) Gd-DTPA infusion. Coronal MRI images of the body were acquired using a 1.5-T superconducting magnet (three with a GE Signa, one with Philips NT), fast spoiled gradient echo (FSPGR); echo time (TE) = 4.2 msec, repetition time (TR) = 68-150 msec, flip = 75 degrees, 0-600 s after dilute Gd-DTPA IA bolus injection during sequential breath-hold acquisitions of 13-32 s each. All arteries were detected with dynamic MR. The FSPGR MRI with IA Gd-DTPA administration can provide adequate time and spatial resolution to demonstrate arterial anatomy and arterial stent patency.

There is a significant re-stenosis rate with percutaneous treatment of stenoses of the infrarenal abdominal aorta with balloon angioplasty. Since 1990 the authors have primarily treated local infrarenal aortic stenoses with metallic endoluminal stents. The authors' experience with 12 consecutive patients (nine women and three men, aged from 30 to 72 years (mean age = 57 years)) is presented. Follow-up is available in 11 cases over 7-78 months (mean 32 months). The procedure was technically successful in all patients. Of the 11 patients with follow-up available, claudication was cured (n = 7) or significantly improved (n = 4). Those with persisting claudication had concurrent distal arterial disease. Periprocedural complications occurred in five cases, with two significant complications. One case required iliac angioplasty for embolized aortic atherosclerotic plaque, and one case required surgical thrombectomy and vein patch for iliac thrombosis complicating iliac dissection, without long-term sequelae in either case. One patient has had recurrent symptomatic aortic stenosis occurring 6 years after initial stenting, which responded to further stent insertion. Primary patency of 91% and secondary assisted patency of 100% has been achieved. Primary treatment of infrarenal aortic stenosis with endoluminal stenting results in high patency rates, with low morbidity and relatively low complication rates.

A case is reported here of effort-related thrombosis of the axillary and subclavian veins (Paget-Schrotter syndrome) treated primarily with a combination of thrombolysis, percutaneous balloon angioplasty (PTA) and stent insertion, but without immediate rib resection. The subsequent course was complicated by fracture of the stent, managed by first rib resection.