The Establishment And Empirical Study Of The Sacral Plexus Explosion Injury In Rabbits

Pelvis Sacral firearm injury is an important part of modern war injuries. Because of complicated anatomical, special physiological functions, more associated injury and complications,there are have high rate of infection,mutilation and mortality.so, it is a tough problem and emphasis of firearm injury treatment. The range of Sacral plexus firearm injury is wide, but almost can't primary repair. So the denervated organs aggravate dysfunction. Modern warfare is more focused on the application of explosive weapons, thus, it's very important significance in military and medical to establish the model of the Sacral Plexus explosion Injury, revealed the laws of neural degeneration and target cells degeneration, for provide the treatment theories of sacral plexus firearm injury and to maximum reduce the disability of injured soldiers.Objective 1,To consider composition and dominance of Plexus and organ in rabbits.2,To establish the model of the Sacral Plexus explosion Injury in Rabbits.3,To observe the changes of Sacral Plexus'direct segment, distal segment(Sciatic nerve), spinal cord neuronal apoptosis, and denervated muscle atrophy following explosion injury of Sacral Plexus in rabbits.Methods 1,There are 10 fresh specimens of rabbits, a total of 20 sides. The incision conclude both previous and posterior. Separated nerves and tissue start from lumbar vertebra foramina and sacral vertebra foramina by knife. Separated from the proximal to distal direction. To detect the beginning and ending of nerves and muscles.2,18 Rabbits were divided into A,B,C groups at random which were injured by electronic explosive detonators contain 600mg TNT. The distance between detonator and skin was lcm in A group,2cm in B group,5cm in C group. The hit point was a triangle formed by posterior median line, the right posterior superior iliac spine with femur connection line, and the level line of the right femur, where was the surface projection of the Sacral Plexus region. The Sacral Plexus nerve injury situation was observed according to record animal injury assessment and short-latency somatosensory evoked potential (SLSEP) at the time of before injury, immediately after injury and 1 w after injury.3,6 rabbits were divided into the control group(A),1d group(B),3d group(C),1w group(D),2w group(E),4w(F) group at random which were injured by electronic explosive detonators contain 600mg TNT. The distance between detonator and skin was 2 cm. The hit point was a triangle formed by posterior median line, the right posterior superior iliac spine with femur connection line, and the level line of the right femur, where was the surface projection of the Sacral Plexus region. The accepted ones were according to short-latency somatosensory evoked potential (SLSEP) disappeared and the Sacral Plexus nerve injuried situation was observed after injuried. According to HE stain,TUNEL and electron microscope,to observe Sacral plexus, sacral and gastrocnemius, to record the number of neurons and neuronal apoptosis by manual counted.Results 1,The sacral nerves were mainly composed of 5-7 lumbar nerves and all anterior branch sacral nerves. The nervous ramification conclude nerves glutaeus cranialis, sciatic nerve, posterior femoral cutaneous nerve, pudendal nerve, meso-rectum nerve, aboral-rectum nerve. The target organs and muscles concluded rectum, appendage urogenitalis, gluteus maximus muscle, gluteus medius muscle, piriform muscle, biceps flexor cruris,semitendinosus,semimembranous muscle, triceps surae muscle, anterior tibial muscle, long fibular muscle, peroneous brevis, peroneus tertius, forth fibular muscle, extensor digitorum longus, extensor pollicis longus, flexor digitorum superficialis muscle,flexor digitorum longus muscle, interosseus,lumbricales.2,The Sacral Plexus were all rupture, survival rate of 1 w was 0 in A group. The Sacral Plexus were bruised in B group and occurred obvious injury symptoms. The SLSEP disappeared immediately after injury,and didn't recover after 1 w, survival rate of 1w was 83%. The skin was hurt but no Sacral Plexus injury symptoms in C group. The SLSEP little changed immediately after injury (p<0.05), but recovered after 1 w compared before injury with no significant difference (p> 0.05), survival rate of 1w was 100%.3,The mainly changes of Sacral Plexus'direct segments were hemorrhage in intraperineurium in Id to 3d. There were appearance scar in Axons after 2 weeks. There Was no significant differences in anterior horn neurons of spinal cord of the injured side 1d-3d after injury in the injury group and the control group(P>0.05), but the neuron number were decreased 1 weeks later in the injury group as compared with that of the control group(P<0.05). Apoptotic neurons were observed in spinal cord in Id group. The peak of apoptosis occurred 3 days after injury, which was similar to 1w group, but had significantly more than the control group and other groups. Gastrocnemius denervated muscle atrophy occurred after 2 weeks. Conclusion 1,The Sacral Plexus anatomy,neural stem composition and the dominant target organs of rabbits are similar to human. Rabbits can be used as experimental animals in sacral plexus study.2,Under the condition of 600mgTNT,2 cm detonator distance,and 51.34±1.03MPa blast pressure in B group,typical Sacral Plexus explosion injury could be gained easily, and the long time pathological changes of injured nerve could be observed.3,The Sacral Plexus explosion injury are widespread and serious. Spinal cord neuronal apoptosis occurred early. Target muscles occurred denervated muscle atrophy. Therefore,the sacral plexus explosion injury need treatment earlier.