Recurrent Superior Mesenteric Artery Stent Fracture.

Ostial stenosis of the superior mesenteric artery (SMA) is usually a benign finding due to the significant collateralization inherent with visceral vessels. There is a subset of patients, however, with significant atherosclerotic disease leading to in situ thrombosis and subsequent mesenteric ischemia requiring intervention. Over the last 20 years, management of mesenteric ischemia-acute or chronic-has transitioned from an open embolectomy or bypass to an endovascular-first approach involving angioplasty and stenting. We are reporting a unique case of recurrent SMA stent fracture with imaging demonstrating diaphragmatic compression of the SMA during the respiratory cycle, subsequent management, and recommendations for future intervention.

Matrix remodeling associated 5 expression in trunk and limb during avian development.

Matrix remodeling associated 5 (MXRA5) is an extracellular protein that is upregulated in several cancers, but little is known regarding its spatial and temporal localization in the developing embryo. The present study was undertaken to investigate MXRA5 transcript expression in the trunk and limb of the embryonic chick to provide groundwork for future investigation of its developmental function. In situ hybridization utilizing digoxigenin-labeled sense control and experimental antisense probes was performed in paraffin sections of chick embryos from Hamburger and Hamilton (HH) stages 18-38. MXRA5 expression was initially low and restricted in extent at the earliest stages examined, but expression increased in strength and tissue distribution with developmental age. Transcripts were largely found in cells of mesodermal origin, including gut associated mesenchyme, tendon and ligament rudiments, intervertebral discs, dermal papillae of feather buds, heart valve precursors and leaflets, as well as in appendicular joint primordia. The present study has provided initial information on MXRA5 gene expression in the trunk and limb of early to mid-stage avian embryos. Results show that MXRA5 was expressed most strongly at sites undergoing change and remodeling of the extracellular matrix during transition of embryonic tissues into the functional adult morphology.

Differences in radial expansion force among inferior vena cava filter models support documented perforation rates.

OBJECTIVE: Inferior vena cava (IVC) filters are used in patients at risk for pulmonary embolism who cannot be anticoagulated. Unfortunately, these filters are not without risk, and complications include perforation, migration, and filter fracture. The most prevalent complication is filter perforation of the IVC, with incidence varying among filter models. To our knowledge, the mechanical properties of IVC filters have not been evaluated and are not readily available through the manufacturer. This study sought to determine whether differences in mechanical properties are similar to differences in documented perforation rates. METHODS: The radial expansion forces of Greenfield (Boston Scientific, Marlborough, Mass), Cook Celect (Cook Medical, Bloomington, Ind), and Cook Platinum filters were analyzed with three replicates per group. The intrinsic force exerted by the filter on the measuring device was collected in real time during controlled expansion. Replicates were averaged and significance was determined by calculating analysis of covariance using SAS software (SAS Institute, Cary, NC). RESULTS: Each filter model generated a significantly different radial expansion force (P < .001), and force was distributed at significantly different rates (P < .001) during expansion. The largest radial expansion force at minimal caval diameter was seen in the Cook Platinum filter, followed by the Cook Celect and Greenfield filters. Radial force dispersion during expansion was greatest in the Cook Celect, followed by the Cook Platinum and Greenfield filters. CONCLUSIONS: Differences in radial expansion forces among IVC filter models are consistent with documented perforation rates. Cook Celect IVC filters have a higher incidence of perforation compared with Greenfield filters when they are left in place for >90 days. Evaluation of Cook Celect filters yielded a significantly higher radial expansion force at minimum caval diameter, with greater force dispersion during expansion.