A new non-craniotomy model of subarachnoid hemorrhage in the pig: a pilot study.

Subarachnoid hemorrhage (SAH) from rupture of an intracranial arterial aneurysm is a devastating disease affecting young people, with serious lifelong disability or death as a frequent outcome. Large animal models that exhibit all the cardinal clinical features of human SAH are highly warranted. In this pilot study we aimed to develop a non-craniotomy model of SAH in pigs suitable for acute intervention studies. Six Norwegian Landrace pigs received advanced invasive hemodynamic and intracranial pressure (ICP) monitoring. The subarachnoid space, confirmed by a clear cerebrospinal fluid (CSF) tap, was reached by advancing a needle below the ocular bulb through the superior orbital fissure and into the interpeduncular cistern. SAH was induced by injecting 15 mL of autologous arterial blood into the subarachnoid space. Macro- and microanatomical investigations of the pig brain showed a typical blood distribution consistent with human aneurysmal SAH (aSAH) autopsy data. Immediately after SAH induction ICP sharply increased with a concomitant reduction in cerebral perfusion pressure (CPP). ICP returned to near normal values after 30 min, but increased subsequently during the experimental period. Signs of brain edema were confirmed by light microscopy post-mortem. None of the animals died during the experimental period. This new transorbital injection model of SAH in the pig mimics human aSAH and may be suitable for acute intervention studies. However, the model is technically challenging and needs further validation.

Form stability of the Style 410 anatomically shaped cohesive silicone gel-filled breast implant in subglandular breast augmentation evaluated with magnetic resonance imaging.

BACKGROUND: In this study, the authors evaluated the form stability of the Style 410 anatomically shaped cohesive silicone gel-filled breast implant after subglandular implantation. METHODS: Nine women who had undergone bilateral subglandular breast augmentation using Style 410 implants were examined in the prone and supine positions with magnetic resonance imaging. RESULTS: In the supine position, the dimensions of the implants were similar to those specified by the manufacturer. In the prone position, there was a mean increase of 29.5 percent (range, 9.7 to 53.3 percent) in implant projection. All implants had their point of maximal projection positioned in the lower pole in both positions. CONCLUSIONS: The Style 410 implant is described as a form-stable, anatomically shaped, cohesive, silicone gel-filled implant. However, its shell and the degree of silicone gel cohesivity allow for a change in form depending on body posture. Compared with the supine position, there was a marked increase in implant projection in the prone position. The Style 410 implant keeps its lower pole fullness after subglandular implantation in both the supine and prone positions.