Morphologic Characteristics of Primary Nonperforative Intestinal Blast Injuries in Rats and Their Evolution to Secondary Perforations

Abstract

Five hundred and fifty Wistar rats were investigated to determine the frequency of secondary intestinal perforations after exposure to nonperforating blasts and the evolution of the morphological changes from hematoma through to necrosis and gangrene. The animals were observed at different times for a period of 14 days from the moment that the injury was inflicted. Microscopic findings showed that alterations began in the mucosal layer where they were most extensive, then spread to the submucosal layer, muscular layer, and serosal layer, respectively. Examination of the intestinal wall revealed an evolution of the injury from hematoma to necrosis to gangrene, resulting in secondary intestinal perforation. The secondary wounds had centrifugal patterns, opposite those of the original wound pathways. Based on these observations, the mechanism of evolution of primary nonperforating intestinal blast injury into secondary intestinal perforations is presented.

Blast-Induced Colon Perforation Secondary to Civilian Gunshot Wound

“…This is typical of a blast injury due to shearing forces and splaying of the tissues, where the mucosa of the gas-containing bowel is most susceptible to injury. The same changes have been reported in delayed bowel rupture after explosions [6,7]. There are two previously reported cases of small bowel injuries secondary to extraperitoneal rifle bullets injuries; one of them had a delayed presentation [1,2].…”

Blast Injuries

“…Contusions of the bowel are notable as they can occasionally result in delayed ''secondary perforation'' of the intestine (7,44). Studies suggest that most of these secondary perforations develop 3 to 5 days after initial injury, but occasionally develop up to 2 weeks later (84). For this reason, a high level of suspicion is essential to making this diagnosis.…”

A thoracic mechanism of mild traumatic brain injury due to blast pressure waves

“…Like ballistic pressure waves, blast waves also cause focal internal injuries, including mTBI (18, 22,28,41,51,52,53,54). These injuries are similar to remote injuries caused by ballistic pressure waves, and may be caused by similar mechanisms.…”