CT and MR imaging of the upper extremity vasculature: pearls, pitfalls, and challenges.

Imaging is needed for diagnosis, treatment planning, and follow-up of patients with pathologies affecting upper extremity vasculature. With growth and evolution of imaging modalities [especially CT angiography (CTA) and MR angiography (MRA)], there is need to recognize the advantages and disadvantages of various modalities and obtain the best possible imaging diagnostic test. Understanding various limitations and pitfalls as well as the best practices to minimize and manage these pitfalls is very important for the diagnosis. This article reviews the upper extremity arterial vascular anatomy, discusses the CTA and MRA imaging, various pitfalls, and challenges and discuss imaging manifestations of upper extremity arterial pathologies.

Infundibulum of the common origin of fourth lumbar arteries and median sacral artery.

We describe an infundibulum of a common origin of the fourth lumbar arteries and the median sacral artery. To the best of our knowledge there has been no such published case thus far and its natural course is unknown, in view of its novelty. Infundibular dilatations in intracranial arteries have been described to progress in size and potentially rupture. Therefore, we recommended follow-up imaging, as part of the management, to ensure stability of the infundibulum.

Maintenance of Hemodialysis Vascular Access and Prevention of Access Dysfunction: A Review.

BACKGROUND: Current Renal Association guidelines recommend the creation of an arteriovenous fistula as the first choice for hemodialysis access, with artificial grafts kept in reserve. However, maintaining working access comes with significant difficulties, as well as an estimated annual cost to the National Health Service of greater than £84 million. Multiple methods of improving the successful creation of hemodialysis access, improving access maintenance and preventing access dysfunction therefore exist. The aim was to review these methods, including surgical, radiological, and pharmacological techniques. METHODS: The literature was reviewed up to March 2016 for reports of surgical, radiological, and pharmacology approaches to improve maturation, maintain function, and prevent dysfunction of arteriovenous fistulas and artificial access grafts. RESULTS: Access function has been related to fistula and graft configuration and anastomotic technique. Novel surgical approaches include the use of early-cannulation grafts and biological grafts. Preoperative radiological vessel mapping and access surveillance have both been studied, and once stenosis or thrombosis has occurred, endovascular management techniques for thrombolysis and thrombectomy, along with angioplasty and stenting, are common. Pharmacological trials include the use of antiplatelets, ACE inhibitors, statins, along with perivascular therapies, and other more novel drug targets. CONCLUSIONS: The evidence for the strategies that can be used to maintain access function is highly variable, with many small, observational, and retrospective studies. In the future, the more widespread use of early cannulation grafts, hybrid surgical and endovascular procedures, and the further pursuit of both biological grafts and biological perivascular therapies may yield improvements in vascular access function.

Mediastinal paraganglioma between the great vessels in an 81-year-old woman.

Nonfunctional paragangliomas are slow-growing, typically benign tumors that arise from the extra-adrenal paraganglion of the autonomic nervous system. They are identified and characterized with the use of computed tomography and other imaging methods; for definitive diagnosis, histopathologic evaluation is crucial. Surgical resection is the treatment of choice, and results of postoperative biochemical testing can reveal recurrence. Because of this lesion's familial association, genetic testing is suggested. We report the case of an 81-year-old woman who presented with neck pain, intermittent palpitations, hypertension, and dyspnea. Contrast-enhanced computed tomography of the chest revealed a multilobular, high-density lesion between the aorta and the pulmonary artery in the superior mediastinum. The patient's 24-hour urinary vanillylmandelic acid levels were not elevated, which suggested a nonfunctional tumor. Mediastinal exploration revealed a large, vascular, irregular, consistently firm mass that adhered to the aortic arch. Upon histopathologic analysis after complete resection, the mass was determined to be a paraganglioma with a low index of mitosis. The patient had postoperative respiratory insufficiency that necessitated tracheostomy, but she recovered well after rehabilitation. In addition to reporting our patient's case, we discuss the nature, diagnosis, and treatment of paragangliomas.

Antiplatelet and anticoagulant drugs for prevention of restenosis/reocclusion following peripheral endovascular treatment.

BACKGROUND: Peripheral arterial disease (PAD) is frequently treated by balloon angioplasty. Restenosis/reocclusion of the dilated segments occurs often, depending on length of occlusion, lower leg outflow, stage of disease and presence of cardiovascular risk factors. To prevent reocclusion, patients are treated with antithrombotic agents. This is an update of a review first published in 2005. OBJECTIVES: To determine whether any antithrombotic drug is more effective in preventing restenosis or reocclusion after peripheral endovascular treatment, compared to another antithrombotic drug, no treatment, placebo or other vasoactive drugs. SEARCH METHODS: For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched 14 February 2012) and CENTRAL (2012, Issue 1). SELECTION CRITERIA: We selected randomised controlled trials (RCTs). Participants were patients with symptomatic PAD treated by endovascular revascularisation of the pelvic or femoropopliteal arteries. Interventions were anticoagulant, antiplatelet or other vasoactive drug therapy compared with no treatment, placebo or any other vasoactive drug. Clinical endpoints were reocclusion, restenosis, amputation, death, myocardial infarction, stroke, major bleeding and other side effects, such as minor bleeding, puncture site bleeding, gastrointestinal side effects and haematoma. DATA COLLECTION AND ANALYSIS: We independently extracted and assessed details of the number of randomised patients, treatment, study design, patient characteristics and risk of bias. Analysis was based on intention-to-treat data. To examine the effects of outcomes such as reocclusion, restenosis, amputation and major bleeding, we computed odds ratios (OR) with 95% confidence intervals (CI) using a fixed-effect model. MAIN RESULTS: Twenty-two trials with a total of 3529 patients are included (14 in the original review and a further eight in this update). For the majority of comparisons, only one trial was available so results were rarely combined in meta-analyses. Individual trials were generally small and risk of bias was often unclear due to limitations in reporting. Three trials reported on drug versus placebo/control; results were consistently available for a maximum follow-up of only six months. At six months post intervention, a statistically significant reduction in reocclusion was found for high-dose acetylsalicylic acid (ASA) combined with dipyridamole (DIP) (OR 0.40, 95% CI 0.19 to 0.84), but not for low-dose ASA combined with DIP (OR 0.69, 95% CI 0.44 to 1.10; P = 0.12) nor in major amputations for lipo-ecraprost (OR 0.89, 95% CI 0.44 to 1.80). The remaining trials compared different drugs; results were more consistently available for a longer period of 12 months. At 12 months post intervention, no statistically significant difference in reocclusion/restenosis was detected for any of the following comparisons: high-dose ASA versus low-dose ASA (OR 0.98, 95% CI 0.64 to 1.48; P = 0.91), ASA/DIP versus vitamin K antagonists (VKA) (OR 0.65, 95% CI 0.40 to 1.06; P = 0.08), clopidogrel and aspirin versus low molecular weight heparin (LMWH) plus warfarin (OR 0.31, 95% CI 0.06 to 1.68; P = 0.18), suloctidil versus VKA: reocclusion (OR 0.59, 95% CI 0.20 to 1.76; P = 0.34), restenosis (OR 1.87, 95% CI 0.66 to 5.31; P = 0.24) and ticlopidine versus VKA (OR 0.71, 95% CI 0.37 to 1.36; P = 0.30). Treatment with cilostazol resulted in statistically significantly fewer reocclusions than ticlopidine (OR 0.32, 95% CI 0.13 to 0.76; P = 0.01). Compared with aspirin alone, LMWH plus aspirin significantly decreased occlusion/restenosis (by up to 85%) in patients with critical limb ischaemia (OR 0.15, 95% CI 0.06 to 0.42; P = 0.0003) but not in patients with intermittent claudication (OR 1.73, 95% CI 0.97 to 3.08; P = 0.06) and batroxobin plus aspirin reduced restenosis in diabetic patients (OR 0.28, 95% CI 0.13 to 0.60). Data on bleeding and other potential gastrointestinal side effects were not consistently reported, although there was some evidence that high-dose ASA increased gastrointestinal side effects compared with low-dose ASA, that clopidogrel and aspirin resulted in fewer major bleeding episodes compared with LMWH plus warfarin, and that abciximab resulted in more severe bleeding episodes. AUTHORS' CONCLUSIONS: There is limited evidence suggesting that restenosis/reocclusion at six months following peripheral endovascular treatment is reduced by use of antiplatelet drugs compared with placebo/control, but associated information on bleeding and gastrointestinal side effects is lacking. There is also some evidence of variation in effect according to different drugs with cilostazol reducing reocclusion/restenosis at 12 months compared with ticlopidine and both LMWH and batroxobin combined with aspirin appearing beneficial compared with aspirin alone. However, available trials are generally small and of variable quality and side effects of drugs are not consistently addressed. Further good quality, large-scale RCTs, stratified by severity of disease, are required.

Technical tips for endovascular treatment of abdominal aortic aneurysms with challenging infrarenal neck anatomy using the Excluder endoprosthesis.

PURPOSE: To report technical tips of endovascular aneurysm repair using Excluder endografts in patients with challenging infrarenal neck anatomy (short, angled, and/or tapered necks). TECHNIQUE: Several tips are presented to achieve effective and durable fixation and sealing of Excluder stent-grafts in abdominal aortic aneurysms (AAA) with challenging necks. The primary approach to patients with short infrarenal necks is a slow and controlled deployment combined with the bending-the-wire technique to realign the axis of the aneurysm and the axis of the neck. Severe infrarenal neck angulation is dealt with by bending the guidewire, orienting the iliac limbs of the Excluder in the anteroposterior direction, and using the slow and controlled endograft deployment technique. Other key procedural factors, such as using the percutaneous approach and local anesthetic, reorienting the stent-graft, using Excluder aortic extensions, employing the endowedge and kilt techniques, and using the appropriate C-arm angulation to adequately visualize the target landing zone, are also useful. CONCLUSION: The techniques we describe have been valuable in achieving excellent outcomes with endovascular AAA treatment using the Excluder endoprosthesis in challenging infrarenal neck anatomy. Further improvements in device design and deployment mechanism will allow better device alignment in patients with complex infrarenal neck anatomy.

Lobectomy for pulmonary vein occlusion secondary to radiofrequency ablation.

Pulmonary vein stenosis, a recognized complication of transcatheter radiofrequency ablation in the left atrium, is often asymptomatic. Significant stenosis is commonly treated with percutaneous balloon dilation with or without stenting. We encountered a case of complete pulmonary vein occlusion that caused lobar thrombosis, pleuritic pain, and persistent cough. Imaging studies revealed virtually no perfusion to the affected lobe. A lobectomy was performed, resolving the persistent cough and pain. Pulmonary vein occlusion should be suspected in patients who present with pulmonary symptoms after having undergone ablative procedures for atrial fibrillation. This condition may necessitate surgical intervention if interventions such as balloon dilation or stenting are not possible or are ineffective.

Endoluminal abdominal aortic aneurysm repair: the latest advances in prevention of distal endograft migration and type 1 endoleak.

Endovascular abdominal aortic aneurysm repair (EVAR) is an attractive alternative to open surgical repair. Distal endograft migration and type 1 endoleak are recognized to be the 2 main complications of EVAR. First-generation endografts had a stronger propensity for distal migration, modular component separation, thrombosis, and loss of structural integrity. Substantial progress has been made in recent years with 2nd- and 3rd-generation devices to prevent these complications. Some of the most common predictors of endograft failure are angulated and short infrarenal necks, large-diameter necks, and thrombus in the aneurysmal sac. The purpose of this study is to describe and review our experience in using innovative techniques and a newer generation of endografts to prevent distal migration and type 1 endoleak in patients with challenging infrarenal neck anatomy. The use of these innovative EVAR techniques and the new generation of endografts in patients with challenging infrarenal neck anatomy has yielded encouraging procedural and intermediate-term results.