Traumatic brain injury (TBI) carries a high risk of death or disability, owing in part to a lack of treatment options. In previous studies, Louis Argenta (Wake Forest University Health Sciences, Winston-Salem, NC) and colleagues found that controlled application of negative pressure to localized areas of TBI in rats promoted healing and improved outcomes. With those results in mind, they sought to refine some parameters of their technique, which they call mechanical tissue resuscitation (MTR), and to evaluate its safety and efficacy in a large-animal model that more closely resembles TBI in humans.

The researchers tested the MTR approach by inducing localized TBI in swine and then applying negative pressure over the injured area (Neurosurgery 75, 152–162; 2014). They evaluated the effects of different levels of pressure (−50 or −100 mmHg), different treatment periods (3 or 5 days) and different delay times (no delay, 3 hours or 6 hours) on the size of the damaged area, the volume of hemorrhage and the appearance of the damaged tissue.

The results showed that MTR after TBI improved outcomes in swine. The procedure seemed to be safe: none of the treated pigs developed seizures or brain deformation. Brain tissue of treated animals had a more normal appearance by magnetic resonance imaging and by histological examination than did tissue of untreated animals. Application of −100 mmHg of pressure for 3 days resulted in significantly smaller damaged areas and less bleeding compared with application of no pressure or of −50 mmHg of pressure. All the animals that were treated by MTR for 5 days after injury survived, whereas half of animals that were treated for only 3 days died when treatment was stopped. Delaying treatment by 3 hours did not diminish its efficacy, but delaying treatment by 6 hours resulted in less benefit.

Argenta's group concludes that “[t]he ability of mechanical tissue resuscitation to achieve meaningful reduction in loss of brain tissue and hemorrhage injury warrants further investigation.” Additional studies are needed to optimize the MTR technique and to address aspects of the technique such as clinical feasibility and management of infection risk before initiating clinical trials in humans with TBI. But the results in swine suggest that MTR holds promise for the treatment of TBI, perhaps in combination with pharmacological approaches. The researchers believe that the technique may also have a role in treating other conditions that involve brain hemorrhage, such as subdural hematoma, stroke and brain tumor resection.