A serum creatinine level (SCr) should be obtained, and an estimated glomerular filtration rate (eGFR) should be calculated within 6 months in the outpatient who is stable and within 1 week for inpatients and patients who are not stable. Patients with an eGFR of ≥ 60 mL/min have an extremely low risk of CIN. The risk of CIN after intra-arterial CM administration appears be at least twice that after intravenous administration. Fluid volume loading remains the single most important measure, and hydration regimens that use sodium bicarbonate or normal saline solution should be considered for all patients with GFR < 60 mL/min who receive intra-arterial contrast and when GFR < 45 mL/min in patients who receive intravenous contrast. Patients are most at risk for CIN when eGFR < 30 mL/min. Additional preventative measures include the following: avoid dehydration, avoid CM when appropriate, minimize CM volume and frequency, avoid high osmolar CM, and discontinue nephrotoxic medications 48 hours before administration of CM.

No abstract

The percutaneous transhepatic approach for the implantation of islet cells into the portal vein is a safe procedure, and together with use of current cell separation techniques and an immunosuppressive regimen, offers a marked advance in the treatment of type 1 diabetes mellitus.

Based upon moderate quality evidence, our review does not support a role for vertebroplasty for treating osteoporotic vertebral fractures in routine practice. We found no demonstrable clinically important benefits compared with a sham procedure and subgroup analyses indicated that results did not differ according to duration of pain ≤ 6 weeks versus > 6 weeks. Sensitivity analyses confirmed that open trials comparing vertebroplasty with usual care are likely to have overestimated any benefit of vertebroplasty. Correcting for these biases would likely drive any benefits observed with vertebroplasty towards the null, in keeping with findings from the placebo-controlled trials.Numerous serious adverse events have been observed following vertebroplasty. However due to the small number of events, we cannot be certain about whether or not vertebroplasty results in a clinically important increased risk of new symptomatic vertebral fractures and/or other serious adverse events. Patients should be informed about both the lack of high quality evidence supporting benefit of vertebroplasty and its potential for harm.

Islet transplantation is being offered increasingly for selected patients with unstable type 1 diabetes. Percutaneous transhepatic portal access avoids a need for surgery, but is associated with potential risk of bleeding. Between 1999 and 2005, we performed 132 percutaneous transhepatic islet transplants in 67 patients. We encountered bleeding in 18/132 cases (13.6%). In univariate analysis, the risk of bleeding in the absence of effective track ablation was associated with an increasing number of procedures (2nd and 3rd procedures with an odds ratio (OR) of 9.5 and 20.9, respectively), platelets count <150 000 (OR 4.4), elevated portal pressure (OR 1.1 per mm Hg rise), heparin dose ≥45 U/kg (OR 9.8) and pre-transplant aspirin (81 mg per day) (OR 2.6, p = 0.05). A multivariate analysis further confirmed the cumulative transplant procedure number (p < 0.001) and heparin dose ≥45 U/kg (p = 0.02) as independent risk factors for bleeding. Effective mechanical sealing of the intrahepatic portal catheter tract with thrombostatic coils and tissue fibrin glue completely prevented bleeding in all subsequent procedures (n = 26, p = 0.02). We conclude that bleeding after percutaneous islet implantation is an avoidable complication provided the intraparenchymal liver tract is sealed effectively.

Multiple sequential islet transplants can be safely performed via the portal vein, provided that care is taken with islet purification and attention is paid to portal venous monitoring.

No abstract

Bone tumors may present as incidental findings, with pain or loss of function, or as fractures. There is a broad range of indications for transarterial embolization (TAE) in primary or metastatic bone tumors: to reduce operative hemorrhagic risks, to simplify or allow more definitive surgery, or in the context of pain palliation, fever, bleeding, or hypercalcemic and other rheological factors. Embolization may also increase tumor sensitivity to chemotherapy or radiation therapy. The procedure itself is often complex with significant risk to adjacent structures and is usually part of a wider treatment strategy. There are many options of embolic agent, techniques, and end points but all aim to devascularize the tumor. Catheter angiography at the time of TAE is used to determine the correct embolic agent and technique with care taken to isolate at risk structures. Many factors determine the best choice of embolic material, probably the most important of which is operator experience. In life-threatening situations or in preoperative embolizations of metastatic tumors, many operators opt for a combination of particulate emboli and stainless steel or platinum coils. Agents discussed include polyvinyl alcohol particles, trisacryl microspheres, gelatin sponge, liquid embolic agents, and embolization coils. Tumor types treated include vascular metastatic lesions, commonly renal cell or thyroid, particularly in locations prone to fracture; giant cell tumors; aneurysmal bone cysts; vertebral hemangiomas, osteosarcomas; arteriovenous malformations; and osteoblastomas. TAE should be considered in the treatment algorithm of primary or secondary bone tumors. Specific benefit is present where there is a high risk of bleeding at surgery, where there is spinal involvement and neural encroachment, where active bleeding is present or in awkward surgical locations where prolonged surgery is anticipated. KEYWORDS: Embolization, bone tumors, metastasesObjectives: Upon completion of this article, the reader should be able to identify which primary or metastatic bone tumors are amenable to embolization and which factors and locations influence the procedural technique and associated risks. The reader should also be able to identify procedures and techniques to increase efficacy and reduce risk as well as be able to choose the correct embolic material. Accreditation: Tufts University School of Medicine (TUSM) is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. Credit: TUSM designates this educational activity for a maximum of 1 AMA PRA Category 1 Credit TM . Physicians should only claim credit commensurate with the extent of their participation in the activity.