| Objective: (1) To investigate the pathological characteristics of seawater immersion following gunshot wound of rabbit's femoral artery;(2) To investigate surgical management of the compound trauma and evaluate its preliminary outcome.Methods: (1) Traumatogenic methods: unilateral femoral arteries of rabbits were impacted by 0.38g steel spheres fired by 7.62mm rifle at muzzle velocity of 600 to 800m/s. After being wounded and dressed, the rabbits in seawater-immersion group were immersed in artificial seawater(saline 25.4, pH8.2-8.4, temperature 21 C) for 30 or 60mins, while the rabbits in single-wounded group were treated without seawater immersion. (2) Pathological observation: 30 rabbits were divided randomly into 3 groups: single-wounded group (SWG), seawater immersion for 30mins group (SIG-I) and seawater immersion for 60mins group (SIG-II). At 2, 4, 6, 8, 12 hours following firearm wounding, the arteries were explored and Segments of arteries measuring 40mm on each side of the gross trauma were excised. Every 10mm of it was examined by light (H.E stain and Verhoeff 's stain) or electron (TEM; SEM) microscopy. (3) Surgical management: 100 rabbits were divided randomly into single-wounded group (SWG) and seawater immersion group (SIG, immersed for 60mins). Ringer's solution with a temperature of 38C was transfused intravenously into the salvaged rabbits in SIG for the purposes of rewarming and anti-shock. While room-temperatured-solution was transfused into rabbits in SWG. In both groups, grossly injuried arteries were excised andblood flow restoration were reconstructed by direct end-to-end anastomosis, reversed autogenous venous grafting(AVG)or cryopreserved homologous arterial grafting(HAG), according to the length of arterial defection. No systemic anticoagulation and antispasm agent was administered before, during, and after operation. At 1, 7, 14, 21 days after operation, blood flow was examined by physical examination, Dopplor ultrasonography, angiography or surgical exploration, and part of anastomotic sites and grafts were harvested for histological observation. The patency rates of two groups were tested by Fisher Exact Probability.Results: (1) Pathological observation: Gross observation: the types of arterial injuries were contusion, complete and incomplete transection,in which complete transection and contusion were the majority and there was only one case of incomplete transection in SWG. Histological observation: the pathological manifestation of complete transection was much more serious in SIG than SWG, which included marked sloughing of ECs, disorder or disrupture of IEL, acidiphilic degeneration and necrosis of SMCs in the media, edema of the intercellular space and infiltration of leucucytes in the adventitia. Primary-wound-track area of arteries in SIG manifested obvious swelling of arterial wall, especially the outside 2/3 of the media, and balloon structures were often detected inside SMCs, and the intercellular space among SMCs was filled with acidiphilic, homogeneous substance. The pathological changes of contused area were much alleviated, and those of shocked area were almost equated with those of SWG. Pathological changes of contusion were more serious in SIG than SWG, including the changes of the media and intima, the higher incidence of thrombosis and longer thrombus. No significant difference was detected between SIG-I and SIG-II. (2) Surgical management: the mortality of SIG and SWG were 10% and 6%, respectively. In complete transection, the patency rate in the first 3 weeks was 80.00%(24/30) in SIG,and 86.67%(26/30) in SWG, and the patency rates of AVG and HAG grafting were not statistically different in both groups (P>0.1). In contusion, the patency rate in the first 3 weeks was 86.67%(13/15) in SIG, and 82.35%(14/17) in SWG. No significant statistic difference was detected in both groups and both injuries (P>0.1). Histological observation showed that the anastomosis sites were lined with endothelium in 3 weeks after operation in both groups, which was longer t...
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