Vertebroplasty and kyphoplasty

Vertebral compression fractures occur more frequently than hip and ankle fractures combined. These fragility fractures frequently result in both acute and chronic pain, but more importantly are a source of increased morbidity and possibly mortality. Percutaneous vertebral augmentation offers a minimally invasive approach for the treatment of vertebral compression fractures. The history, technique, and results of vertebroplasty and kyphoplasty are reviewed. Both methods allow for the introduction of bone cement into the fracture site with clinical results indicating substantial pain relief in approximately 90% of patients.     

Influence of beta-blocker therapy on aortic blood flow in patients with bicuspid aortic valve

In patients with bicuspid aortic valve (BAV), beta-blockers (BB) are assumed to slow ascending aorta (AAo) dilation by reducing wall shear stress (WSS) on the aneurysmal segment. The aim of this study was to assess differences in AAo peak velocity and WSS in BAV patients with and without BB therapy. BAV patients receiving BB (BB+, n = 30, age: 47 ± 11 years) or not on BB (BB?, n = 30, age: 46 ± 13 years) and healthy controls (n = 15, age: 43 ± 11 years) underwent 4D flow MRI for the assessment of in vivo aortic 3D blood flow. Peak systolic velocities and 3D WSS were calculated at the anterior and posterior walls of the AAo. Both patient groups had higher maximum and mean WSS relative to the control group (p = 0.001 to p = 0.04). WSS was not reduced in the BB+ group compared to BB? patients in the anterior AAo (maximum: 1.49 ± 0.47 vs. 1.38 ± 0.49 N/m², p = 0.99, mean: 0.76 ± 0.2 vs. 0.74 ± 0.18 N/m², p = 1.00) or posterior AAo (maximum: 1.45 ± 0.42 vs. 1.39 ± 0.58 N/m², p = 1.00; mean: 0.65 ± 0.16 vs. 0.63 ± 0.16 N/m², p = 1.00). AAo peak velocity was elevated in patients compared to controls (p < 0.01) but similar for BB+ and BB? groups (p = 0.42). Linear models identified significant relationships between aortic stenosis severity and increased maximum WSS (β = 0.186, p = 0.007) and between diameter at the sinus of Valsalva and reduced mean WSS (β = ?0.151, p = 0.045). Peak velocity and systolic WSS were similar for BAV patients irrespective of BB therapy. Further prospective studies are needed to investigate the impact of dosage and duration of BB therapy on aortic hemodynamics and development of aortopathy.     

Video-assisted thoracic surgical procedure: management of a solitary pulmonary nodule.

Solitary pulmonary nodules continue to challenge all diagnostic skills. Herein we describe video-assisted thoracic surgical intervention, a new, minimally invasive technique that aids physicians in obtaining a definitive histologic diagnosis in a select group of patients with an indeterminate solitary pulmonary nodule.     

A physiologic differentiation between delayed and immediate hypersensitivity

Studies have been made of movement of various macromolecules into and out of the pleural space of guinea pigs during the course of a delayed hypersensitivity reaction to purified protein derivative (PPD), and a passively transferred immediate hypersensitivity reaction to ovalbumin. While the immediate hypersensitivity reaction transiently alters vascular permeability as shown by increased movement of macromolecules into the chest, the delayed hypersensitivity reaction is marked by a decreased capacity to resorb macromolecules from the pleural space. The data suggest that the two hypersensitivity reactions may be distinguished by these physiologic differences. Additional data from studies of a chemically induced pleural effusion in these animals suggest that some type of outflow obstruction is necessary for the development of effusion, but that the outflow defect caused by the irritating chemical is based on a different mechanism than that seen during the delayed hypersensitivity reaction.