Reduction of capsular thickness around silicone breast implants by zafirlukast in rats.

Capsular contracture is a very disappointing complication, with an overall incidence between 0.5 and 30% of breast implant operations and, if severe, requiring a further surgical procedure (capsulotomy or capsulectomy). Many frustrating attempts have been made to prevent the fibrotic reaction, mainly with steroids or antibiotics. More recently leukotriene antagonists clinically used in the asthma and lung diseases have been suggested to be potentially useful in counteracting the inflammatory pathway leading to a dense collagen membrane around the prosthesis and thus preventing contracture of the capsule. In this study we evaluated the effectiveness of zafirlukast with the following protocol. Disks of textured implant material were placed dorsally into each of the subcutaneous tissues of 40 rats that were subdivided in 2 groups: 20 rats treated with zafirlukast and 20 controls. At autopsy 77 days after, each implant with its surrounding collagenic tissue was excised, and the macroscopic measure of the membrane thickness was compared with the pathology reports, to definitely assess the foreign body reaction. The mean total thickness of the capsule around the implants was 161.97 microm in the zafirlukast-treated group compared with 345.98 microm in the control group (p < 0.001). Outstandingly, the collagen fibers and fibroblast layer were reduced in the zafirlukast-treated group compared to the controls. Our study confirms the effectiveness of this compound in preventing fibrosis and putatively also in reducing the extent of collagen reaction when a capsule has been formed.

The mechanisms of blood vessel closure in humans by the application of ultrasonic energy.

BACKGROUND: The use of the ultrasonically activated scalpel (UAS) for vessel closure has attained widespread acceptance in many surgical fields. The aim of our study was to investigate the electron microscopic changes to the blood vessels after the application of UAS. METHODS: We collected 10 arterial and 10 venous segments from vessels that had previously been closed by UAS during abdominal operations. The samples were then prepared for ultramicroscopic analysis. Pathological changes in the lumen and the three wall layers of the blood vessel were examined under scanning and transmission electron microscopy. RESULTS: All of the vessel segments showed similar changes: the presence of a blood clot, endothelial cell condensation, coagulative necrosis of the wall, and charring of the vessel at its tip. The edge of the cut vessel were closed by the coagulation bond, which was tied up by collagen fibrils escaped from denaturation. CONCLUSION: When ultrasonic energy is applied to tissues, it changes their structure so as to make a new extracellular matrix.