Richard J. Owen

US-guided Puncture of the Internal Jugular Vein: Complications and Anatomic Considerations

PURPOSE To examine success and complication rates for ultrasound (US)-guided cannulation of the internal jugular vein (IJV) in comparison with blind techniques and to present the variations in anatomy of the IJV. MATERIALS AND METHODS Data were prospectively collected for 869 cases of sonographically guided cannulation of the IJV. In all cases, the side of the puncture, procedural success or failure, and any immediate complications were recorded. In 764 (88%) cases, the number of passes required and whether a single- or double-wall puncture was used were recorded. In 690 (79%) cases, IJV diameter and depth were recorded, while its relationship to the common carotid artery (CCA) was noted in 659 (76%) cases. RESULTS Cannulation was successful in 868 (99.9%) cases. Complications occurred in 20 (2.3%) cases. Eighty-seven percent of cannulations were achieved with one pass and 83% with a single-wall puncture. Success at first pass was significantly correlated with right-sided puncture and the diameter of the IJV. In 5.5% of cases, the IJV lay medial to the CCA, making successful cannulation with use of the landmark technique unlikely. CONCLUSIONS US-guided cannulation of the IJV is superior to blind techniques, increasing the success rate and incidence of first pass cannulation and reducing the incidence of complications.

Canadian Association of Radiologists Consensus Guidelines for the Prevention of Contrast-Induced Nephropathy: Update 2012

Purpose Contrast-induced acute kidney injury or contrast-induced nephropathy (CIN) is a significant complication of intravascular contrast medium (CM). These guidelines are intended as a practical approach to risk stratification and prevention. The major risk factor that predicts CIN is pre-existing chronic kidney disease. Methods Members of the committee represent radiologists and nephrologists across Canada. The previous guidelines were reviewed, and an in-depth up-to-date literature review was carried out. Results 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.

Prevention of Bleeding After Islet Transplantation: Lessons Learned from a Multivariate Analysis of 132 Cases at a Single Institution

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.

Locoregional radiological treatment for hepatocellular carcinoma; Which, when and how?

Hepatocellular carcinoma (HCC) is one of the most frequent and deadliest cancers worldwide. Liver transplantation, surgical resection or local ablation offer the best survival advantages but most patients either present when the tumor is in an advanced stage or the degree of underlying liver disease precludes these options. Several therapies have been proposed for these patients with proven survival benefits. These therapies comprise the locoregional treatment for HCC, and include percutaneous ethanol injection (PEI), radiofrequency ablation (RFA), transarterial chemoembolization (TACE), transarterial radioembolization (TARE), and drug-eluting bead (DEB). PEI and RFA are considered curative treatments for early stage HCC; whereas TACE is a standard of care for intermediate stages. Additionally, evaluation of response to locoregional treatment in HCC is important, as objective response may become a surrogate marker for improved survival. Currently, there are several criteria for response assessment, including the World Health Organization (WHO), the Response Evaluation Criteria in Solid Tumors (RECIST), the European Association for the Study of the Liver Criteria (EASL), and the modified RECIST (mRECIST); however, there has been poor correlation between the clinical benefit provided by locoregional interventional therapies and conventional methods of response assessment. The aim of our study was to review and analyze the current evidence for radiological interventions in HCC, and to propose evidence based recommendations to improve the management of these patients.

Effects of probiotic therapy on portal pressure in patients with cirrhosis: a pilot study

Background: Recent literature has supported the role of bacterial translocation as a mediator of splanchnic vasodilatation and portal hypertension. The objective of this study was to determine whether the probiotic VSL#3 would reduce portal pressure in patients with cirrhosis.

Role of Imaging in Clinical Islet Transplantation

Islet transplantation is an innovative and effective clinical strategy for patients with type 1 diabetes whose clinical condition is inadequately managed even with the most aggressive medical treatment regimens. In islet transplantation, purified islets extracted from the pancreas of deceased donors are infused into the portal vein of the recipient liver. Engrafted islets produce insulin and thus restore euglycemia in many patients. After islet transplantation performed with the original Edmonton protocol, 80% of patients were insulin independent at 1 year and approximately 20% were insulin independent at 5 years. With more recent technical advances, 50% of patients or more maintain insulin independence 5 years after islet transplantation. The success rate with single-donor islet infusions has markedly improved over time. Even in patients who lose insulin independence, islet transplantation is considered successful because it provides improved glycemic control and a higher quality of life. Imaging plays an important role in islet transplantation and is routinely used to evaluate potential recipients, guide the transplantation process, and monitor patients for posttransplantation complications. Because of the success of islet transplantation and its increasing availability worldwide, familiarity with the role of imaging is important.

Endovascular repair in traumatic thoracic aortic injuries: comparison with open surgical repair.

PURPOSE Thoracic endovascular aortic repair (TEVAR) has emerged as an alternative to open surgical repair (OSR) of traumatic thoracic aortic injury (TTAI). Herein immediate and midterm outcomes of TEVAR are compared with those of OSR. MATERIALS AND METHODS Health records were used to identify patients with TTAI presenting between April 1995 and September 2006. Preoperative patient characteristics, intraoperative variables, procedural costs, and outcomes were recorded. RESULTS A total of 103 patients were identified. Twenty-two died before treatment, 19 were treated conservatively, 36 received OSR, and 26 received TEVAR. In the OSR group, time from diagnosis to treatment was 8 hours, the 30-day mortality rate was 11.1%, and all deaths occurred intraoperatively. Thoracic nerve injury occurred in four patients (12.5%), pneumonia in 12 (37.5%), temporary renal failure in one (3%), paraparesis in three (9.4%), and paraplegia in five (15.6%). On follow-up (mean, 61 months), postthoracotomy pleural reaction was seen in three cases (9.4%). In the TEVAR group, time to treatment was 38 hours (P < .01) and the 30-day mortality rate was 7.4% with no intraoperative deaths. Pneumonia was seen in two cases (8.3%) and left arm ischemia was seen in two of 17 patients in whom the left subclavian artery was covered. On midterm follow-up (mean, 17 months), there were no graft failures or repeat aortic interventions. Costs of each procedure were initially comparable, but follow-up expenses with TEVAR were

VSL#3® probiotic therapy does not reduce portal pressures in patients with decompensated cirrhosis

1,284 (Canadian) greater per year. CONCLUSIONS TEVAR of TTAI is associated with lower perioperative mortality and morbidity rates than OSR, with no significant graft-related complications on midterm follow-up. The study data support the continued use of TEVAR in this context.

Embolization of Musculoskeletal Tumors

In patients with decompensated cirrhosis, bacterial translocation can contribute to splanchnic vasodilatation, decreased effective circulating volume, and portal hypertension. The primary objective of this randomized, double blind placebo controlled trial was to evaluate the effect of the probiotic VSL#3® on the hepatic venous pressure gradient (HVPG).

Transarterial chemoembolization in patients with hepatocellular carcinoma: predictors of survival.

Transarterial embolization 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.