Lateral geniculate artery pseudoaneurysm after arthroscopic medial meniscectomy.

Vascular complications after arthroscopy are rare and generally present as transient paresthesia most likely due to nervous injury or vasospasm. Rare cases of genicular artery injuries can occur and generally involve the medial genicular artery due to proximity to the right arthroscopic knee hook. This case, however, represents a rare lateral inferior genicular artery injury resulting in a symptomatic pseudoaneurysm. In addition, during the workup, the best visualization of the pseudoaneurysm was possible using duplex ultrasound. The diagnostic information seen on ultrasound was paramount and superseded the findings from conventional angiography and computed tomography angiography, both of which were nonspecific. In brief, this case not only highlights a rare surgical complication but also emphasizes the importance of duplex ultrasound compared with angiography and computed tomography in the workup of pseudoaneurysms.

Urinary excretion after transcaval renal penetration of a fragmented Bird's Nest filter.

Permanent inferior vena cava (IVC) filters are used to prevent venous thromboembolic events in select populations of patients. The Bird's Nest filter (BNF; Cook Medical, Bloomington, Ind) is an IVC filter that has been associated with various complications including filter strut fractures, migration, caval wall perforation, visceral perforation, and vascular injury. We report a case of a BNF that eroded transmurally through the IVC into the right kidney parenchyma. The patient underwent operative intervention with removal of the BNF with an uncomplicated postoperative course. In patients with symptoms and local filter perforations, we advocate for safe filter removal when possible to avoid long-term damage.

Endovascular repair of an axillary artery pseudoaneurysm attributed to hyperextension injury.

Evolution of endoluminal technologies, enhanced stent designs, and smaller delivery systems have increased the potential for using covered stents to treat the spectrum of traumatic arterial injuries. Improved stent-graft flexibility, reduced fracture potential, and a greater variety of lengths and diameters have increased the versatility for use in axillary and subclavian locations. Open repair of traumatic arterial injuries in the chest and shoulders can result in significant morbidity and mortality. By avoiding the acute area of injury through the use of interventional endovascular techniques, covered stent repair has become a competitive option to open surgery. We report a patient with an unusual mechanism for a traumatic axillary artery pseudoaneurysm that was repaired using a polytetrafluoroethylene-covered stent-graft.

Temporal genomics of vein bypass grafting through oligonucleotide microarray analysis.

OBJECTIVE: Autologous vein is the conduit of choice for small artery reconstruction. Despite excellent patency, these conduits undergo remodeling over time. The purpose of this study was to identify temporal gene expression in vein grafts versus control veins through microarray analysis. METHOD: Cephalic vein grafts (n = 12) were used to bypass femoral arteries in canines. Vein grafts were harvested after 1, 7, 14, and 30 days. Normal contralateral cephalic vein served as control. Total RNA was isolated; its quantity and quality were confirmed with spectrophotometry and gel electrophoresis. Affymetrix U133A GeneChips, comprising approximately 15,000 genes, were used to analyze differential gene expression at each time point. Statistical analysis was performed with Affymetrix and dChip software to identify consistently upregulated and downregulated genes. Real-time, quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and immunohistochemistry were used to validate microarray data. RESULTS: Statistical analysis revealed that 49 genes were consistently upregulated and 31 genes were consistently downregulated in all three animals at various time points. qRT-PCR to quantitatively assess messenger RNA expression was performed on specific genes to validate the microarray data. Immunohistochemistry to qualitatively assess protein expression was used for further validation. Hierarchical clustering with dChip identified additional genes with similar temporal or functional expression patterns. CONCLUSIONS: This is the first study to use microarray analysis with confirmatory qRT-PCR to identify altered genes after vein bypass grafting. Oligonucleotide microarrays and hierarchical clustering are powerful tools to generate hypotheses as the basis for additional research on gene expression in vein graft remodeling. Ultimately, identification of a temporal sequence of differential gene expression may provide insights not preferred into the molecular mechanisms of vein graft remodeling, but also into the pathways leading to intimal hyperplasia.

Temporal gene expression following prosthetic arterial grafting.

BACKGROUND: Following prosthetic arterial grafting, cytokines and growth factors released within the perianastomotic tissues stimulate smooth muscle cell proliferation and matrix production. While much in vitro work has characterized this response, little understanding exists regarding the sequential up- and down-regulation of genes following prosthetic arterial grafting. This study evaluates temporal gene expression at the distal anastomosis of prosthetic arterial grafts using microarray analysis. METHODS: Expanded polytetrafluoroethylene (ePTFE) carotid interposition grafts (n = 12) were surgically implanted into mongrel dogs. Distal anastomotic segments were harvested at 7, 14, 30, or 60 days. Contralateral carotid artery served as control. Total RNA was isolated from the anastomotic tissue and paired controls. Samples were probed with oligonucleotide microarrays consisting of approximately 10000 human genes to analyze differential gene expression at each time point. RESULTS: Forty-nine genes were found to be up-regulated and 37 genes were found to be down-regulated at various time points. Six genes were found to be consistently up-regulated at all time intervals, including collagen type 1 alpha-1 and alpha-2, 80K-L protein (MARCKS), and osteopontin. Six genes were found to be consistently down-regulated, including smoothelin and tropomyosin 2. RT-PCR and immunohistochemistry confirmed the microarray data. CONCLUSIONS: This study uses microarray analysis to identify genes that were temporally up- and down-regulated after prosthetic arterial grafting. Genes with similar patterns of expression have been identified, providing insights into related cellular pathways that may result in the formation of anastomotic intimal hyperplasia.