Nassir Rostambeigi

An in situ forming biodegradable hydrogel-based embolic agent for interventional therapies

We present here the characteristics of an in situ forming hydrogel prepared from carboxymethyl chitosan and oxidized carboxymethyl cellulose for interventional therapies. Gelation, owing to the formation of Schiff bases, occurred both with and without the presence of a radiographic contrast agent. The hydrogel exhibited a highly porous internal structure (pore diameter 17±4 μm), no cytotoxicity to human umbilical vein endothelial cells, hemocompatibility with human blood, and degradability in lysozyme solutions. Drug release from hydrogels loaded with a sclerosant, tetracycline, was measured at pH 7.4, 6 and 2 at 37°C. The results showed that tetracycline was more stable under acidic conditions, with a lower release rate observed at pH 6. An anticancer drug, doxorubicin, was loaded into the hydrogel and a cumulative release of 30% was observed over 78 h in phosphate-buffered saline at 37°C. Injection of the hydrogel precursor through a 5-F catheter into a fusiform aneurysm model was feasible, leading to complete filling of the aneurysmal sac, which was visualized by fluoroscopy. The levels of occlusion by hydrogel precursors (1.8% and 2.1%) and calibrated microspheres (100-300 μm) in a rabbit renal model were compared. Embolization with hydrogel precursors was performed without clogging and the hydrogel achieved effective occlusion in more distal arteries than calibrated microspheres. In conclusion, this hydrogel possesses promising characteristics potentially beneficial for a wide range of vascular intervention procedures that involve embolization and drug delivery.

Cost effectiveness of radioembolization compared with conventional transarterial chemoembolization for treatment of hepatocellular carcinoma

PURPOSE To assess cost effectiveness of radioembolization versus conventional transarterial chemoembolization. MATERIALS AND METHODS The cost of radioembolization versus conventional transarterial chemoembolization was determined based on Medicare reimbursements. Three patient subgroups were defined based on the Barcelona Clinic Liver Cancer (BCLC) classification system (A, B, or C). Efficacy and safety outcomes after each procedure were obtained from the literature. A Monte Carlo case-based simulation was designed for 60 months in 250 patients in each subgroup. Survival was calculated based on average survival from the literature and the Monte Carlo model. The primary outcome was the cost effectiveness of radioembolization over transarterial chemoembolization by considering calculated survival. RESULTS The costs approached

Effect of MRI Versus MDCT on Milan Criteria Scores and Liver Transplantation Eligibility

17,000 for transarterial chemoembolization versus

Impact of an Electronic Medical Record-Based Clinical Decision Support Tool for Dysphagia Screening on Care Quality

31,000 or

Combination of noninvasive neurovascular imaging modalities in stroke patients: patterns of use and impact on need for digital subtraction angiography.

48,000 for unilobar or bilobar radioembolization, respectively. Based on the simulation, median estimated survival was greater with transarterial chemoembolization than radioembolization in BCLC-A and BCLC-B subgroups (40 months vs 30 months and 23 months vs 16 months, respectively, P = .001). However, in the BCLC-C subgroup, survival was greater with radioembolization than transarterial chemoembolization (13 months vs 17 months, P = .001). The incremental cost-effectiveness ratio of radioembolization over transarterial chemoembolization in the BCLC-C subgroup was

Mucinous adenocarcinoma of trachea: a rare case of primary tracheal tumor.

360 per month. The results were dependent on bilobar versus unilobar radioembolization and the total number of radioembolization procedures. CONCLUSIONS The model suggests radioembolization costs may be justified for patients with BCLC-C disease, whereas radioembolization may not be cost effective in patients with BCLC-A disease; however, many patients with BCLC-C disease have extensive disease precluding locoregional therapies. Secondary considerations may determine treatment choice in more borderline patients (BCLC-B disease) because there is no persistent survival benefit with radioembolization.

Small hepatocellular carcinomas displayed as a ring enhancing mass on arterial phase MRI in the chronically diseased liver

OBJECTIVE The Milan criteria for the selection of patients with hepatocellular carcinoma (HCC) for liver transplantation were originally based on the findings of contrast-enhanced CT examinations. Studies have shown improvement in HCC detection of using contrast-enhanced MRI instead of CT, but they have provided little information on the potential downstream effect on patient management that might result from discrepant imaging findings. We sought to assess the effect of discrepant imaging findings on patient eligibility to undergo liver transplantation. MATERIALS AND METHODS From 2006 to 2013, patients with a diagnosis of HCC who underwent both MDCT and MRI examinations within a 40-day period were studied retrospectively. All examinations were independently reviewed by two abdominal radiologists who recorded the number, diameter, and location of each lesion. Secondary confirmation of the lesions was made on the basis of histopathologic findings, diffusion restriction on DWI, increased T2 signal intensity, lesion growth, presence of fat, uptake of ethiodized oil, or a combination of these findings. RESULTS Sixty-four patients (48 men and 16 women; mean age, 62 years) met the criteria for inclusion in the study. Of the 129 lesions identified by MRI, only 102 of these lesions (79%) were identified by MDCT. This discrepancy led to a difference in the Milan criteria scoring for nine patients (14%). There was no statistically significant difference in the mean (± SD) greatest lesion diameter measured using the two modalities, with measurements of 3.52 ± 2.8 cm and 3.46 ± 2.8 cm noted on MDCT and MRI, respectively (p = 0.8). Lesions missed on MDCT studies tended to be smaller, with a mean diameter of 2.7 cm. Of the 129 lesions identified by MRI, 112 (87%) had available histopathologic findings or other confirmatory diagnostic evidence. CONCLUSION MDCT missed one-fifth of the HCC lesions detected by MRI. Had MDCT been the only imaging examination performed, failure to identify these lesions would have led to a different management plan for 14% of patients.

Fibromuscular Dysplasia in a Normotensive Patient Presented with Renal Infarct: Case Report and Endovascular Technique

Background and Purpose— Dysphagia screening (DS) before oral intake in patients with acute stroke is a hospital-level performance measure. We report outcomes of an initiative to improve compliance to this quality measure. Methods— The design was a pre- versus postintervention comparison study. The Intervention was an electronic medical record-based clinical DS system embedded within stroke admission orders. The clinical DS was designed to facilitate DS in patients with stroke. The primary outcome was compliance to a process measure in patients with ischemic stroke: performance of a swallow screen before oral intake. Results— DS measure compliance increased from 36% to 74% (P=0.001). Chart audits found screened patients were more likely to have clinical DS-embedded admission orders initiated or stroke unit admission. Conclusion— The electronic medical record offers a ready platform for clinical DS implementation. DS is a difficult performance measure to improve. The described clinical DS has the potential for improving performance on this challenging care quality measure.

Stent placement versus angioplasty for hepatic artery stenosis after liver transplant: a meta-analysis of case series

BACKGROUND The diagnostic work-up of acute stroke relies on the use of proper imaging studies. We sought to determine the use of a combination of 2 noninvasive tests, namely magnetic resonance angiography (MRA) and computed tomographic angiography (CTA) in diagnosing vascular lesions and the necessity for a subsequent digital subtraction angiography (DSA) for the definitive diagnosis. METHODS Patients admitted to 2 comprehensive stroke centers between January 2008 and July 2010 who had an equivocal initial noninvasive test were reviewed. The proportions of patients who underwent CTA and MRA in combination and those who required additional DSA for definitive diagnosis were determined. The diagnostic yield and impact on management in patients with CTA and MRA combination was compared with patients who underwent CTA and MRA followed by DSA. RESULTS Among a total of 1063 patients (mean age ± SD 63 ± 16), 384 (36%) underwent >1 vascular imaging study. There was no difference in the rates of cardiovascular risk factors and stroke subtype between different combination groups. The agreement between CTA and MRA was high (concordance 81%). Among the 164 patients who underwent both CTA and MRA, a DSA was required for resolution/confirmation in only 27 (16%) patients. Among these 27, DSA findings changed the clinical decision-making in 22 (82%) patients (11 stenotic severities and 11 diagnoses of arteriovenous fistula, aneurysm, or dissection). CONCLUSIONS In our experience, a combination of CTA and MRA was frequently used in patients in whom the initial noninvasive imaging was determined insufficient. The combination of findings from CTA and MRA were considered adequate in a large portion of patients resulting in a lower requirement for DSA and higher treatment impact from DSA.

Comprehensive immune monitoring reveals profound immunological changes in pancreas after kidney (PAK) transplant recipients

A primary tracheal tumor is not common, but adenocarcinoma is particularly rare. We describe a case of primary tracheal mucinous adenocarcinoma misdiagnosed as asthma in a 17-year-old girl. Computed tomography revealed an intraluminal partially obstructing mass in the mid portion of the trachea. A sleeve resection of the involved trachea with primary anastomosis was performed, followed by adjuvant radiotherapy. After 23 months of follow-up, there has been no recurrence.