Martin Thurnher

Pulmonary reaction during intramedullary fracture management in traumatic shock: an experimental study.

Immediate nailing of shaft fractures in severely injured patients causes fat embolization. This method therefore is considered potentially dangerous, since fat intravasation in association with multiple trauma and subsequent endotoxemia might lead to pulmonary dysfunction. We therefore studied the pathophysiologic events of intramedullary nailing in the lungs of sheep with chronic instrumentation including lung lymph fistula. In the 7 animals in group I closed nailing of the intact tibia and femur was performed. Group II (n = 7) animals sustained hypovolemic shock and retransfusion prior to nailing, while group III (n = 11) animals were treated like those in group II and further challenged on the following two days with endotoxin. Group III was compared with group IV (n = 6), in which endotoxin was given only once without additional trauma. Nailing in group I led to a significant increase of the MPAP from 10.8 to 13.8 mm Hg postoperatively (p < 0.05), but no increase in lung permeability. Only additional hypovolemia, retransfusion and nailing as performed in groups II and III showed significant increase of the lymph flow (QI) from 4.4 mL/h to 12.4 mL/h and the protein clearance (Pclear) from 3 to 6.3. A significant difference of the pulmonary permeability between group I and II was only observed postoperatively. There was no difference in the lung response between group III and IV. This ovine study corroborates that although nailing causes a moderate increase in pulmonary pressure, it does not lead to increased lung permeability. Only additional hemorrhagic shock, even when adequately resuscitated, leads to lung disturbance postoperatively. The subsequent endotoxin challenge does not aggravate lung injury.

Nailing versus plating in thoracic trauma : An experimental study in sheep

In this study, femoral intramedullary pressure, fat embolization, and pulmonary response were measured during reamed and unreamed nailing and plating of femoral fractures after blunt thoracic trauma. Intramedullary peak pressures of 425 mm Hg (mean 205 mm Hg) occurred in the reamed nail group (group I) during reaming with the 9-mm reamer, while in the unreamed nail group (group II) peak values were seen during nail insertion (330 mm Hg) with a mean of 203 mm Hg. Plating never led to a pressure rise over 67 mm Hg (mean 37 mm Hg). In reamed nailing, the most intense embolism was identified under ultrasound imaging with the large awl and with the 9.0-mm reamer (mean 2.2) and in the unreamed nail group during nail insertion (mean 2.8). Minimal echoes appeared during plating. The pulmonary arterial pressure did not vary significantly postoperatively between the three groups (p < 0.08). Our findings indicate that intramedullary fracture fixation causes a higher increase of intramedullary pressure and more fat and bone marrow embolization than extramedullary ones. Nevertheless, only minimal differences in the pulmonary hemodynamic response (pulmonary arterial pressure) were noted even in the presence of thoracic trauma.

Fresh autogeneic, frozen allogeneic, and decalcified allogeneic bone grafts in dogs

In fully-grown mongrel dogs, diaphyseal ulnar defects 25 mm long were stabilised by screws and plates, and were temporarily filled with silicone rubber blocks. After eight weeks the block was replaced either by fresh autogeneic cancellous bone, allogeneic deep-frozen cancellous bone, allogeneic decalcified bone matrix, or bone matrix gelatin. After 24 weeks the implants were evaluated by radiography, histology, and measurements of new bone volume, using computer-assisted density registration on microradiographs. Only the autogeneic bone grafts led to healing in all instances. Bone regeneration in the other groups was not significantly better than in the sham group in which no graft was employed. Decalcified bone matrix proved ineffective.

Local and systemic reactions after lung contusion: an experimental study in the pig.

ABSTRACT The present study was designed to investigate the consequences of isolated unilateral lung contusion on local alveolar and systemic inflammatory responses in an animal model in the pig. Isolated unilateral lung contusion was induced by bolt shot in eight mechanically ventilated animals under general anesthesia (sham: n = 4). Plasma and bronchoalveolar lavage fluid were collected during a period of 8 h following lung contusion. Leukocytes, leukocyte neutral protease inhibitor (LNPI), terminal complement complex (TCC), thrombin-antithrombin-complex (TAT) as well as pulmonary microvascular permeability and surfactant function were determined. Within 30 min, lung contusion was found to cause a significant local and systemic increase in TCC and TAT concentrations and a systemic increase in LNPI concentrations. The latter was accompanied by a sequestration of leukocytes in the contused lung. Complement activation and leukocyte sequestration in the contused lung progressively increased during the investigation period. Although surfactant function decreased in the entire lung 30 min after contusion, TCC, TAT, and leukocyte sequestration was unchanged in the contralateral lung. The first indication of an involvement of the contralateral lung was obtained by an increase in leukocyte sequestration 8 h after lung contusion. Unilateral lung contusion initiates an early systemic activation of humoral and cellular defense systems. Involvement of the contralateral lung appears to be a secondary event caused by a systemic inflammatory reaction.

Irradiation-sterilization of rat bone matrix gelatin

Bone matrix gelatin induces bone formation in muscle, and when implanted orthotopically it improves bone repair. Co-60 sterilization of bone gelatin impairs the protein-bound induction mechanisms. Gelatin samples nonirradiated or irradiated by 25 or 50 kGy were implanted into a pouch in the abdominal wall of Sprague-Dawley rats, as well as into a 7-mm calvarial defect. Evaluation was done by histologic studies, histomorphometry of orthotopic implants, and determination of alkaline phosphatase in ectopic implants. Gelatin irradiated with 50 kGy was absorbed in the muscle bed without evidence of any specific host reaction. Irradiation of 25 kGy led to histologically confirmed ectopic bone formation, but the wet weight of the explants was only half that of the nonirradiated control samples. Alkaline phosphatase activity was equal in both of these groups. With orthotopic implantation, neither a histologic nor a morphometric effect was seen with 25 kGy. Loss of osteoinduction with 25-kGy irradiation is apparently masked by osteoconductive mechanisms with orthotopic implantation.

Gelatin Thrombin Granules for Hemostasis in a Severe Traumatic Liver and Spleen Rupture Model in Swine

BACKGROUND Treatment of traumatic liver and spleen rupture is a major challenge for the surgeon. Because of their excellent blood supply and tissue structure, rupture of the liver and spleen is often associated with massive abdominal hemorrhage. Frequently the surgeons only feasible option is partial or total resection of the organ. The purpose of this study was to test the hemostatic efficacy of gelatin thrombin granules (FloSeal) in a standardized severe traumatic liver and spleen rupture model in swine (representing a grade IV-V rupture) during severe hemorrhagic shock and coagulation disorder. METHODS Standardized combined penetrating liver and spleen rupture was inflicted in 10 anesthetized swine. Hemorrhagic shock was induced after heparinization. Gelatin thrombin granules were used to treat both the ruptured liver and the ruptured spleen. Blood loss, hemostasis, and 48 hours survival rate were quantified. Cardiorespiratory parameters, activated clotting time, and plasma fibrinogen level were monitored. After 1 hour and 48 hours a second look evaluation was performed to detect any postoperative hemorrhage. Ruptures were then examined macroscopically and histologically. RESULTS Hemostasis was achieved with FloSeal in all swine. The mean amount of FloSeal used was 14 mL +/- 2.5 mL. Macroscopic and histologic findings after 48 hours showed excellent clot integration into the surrounding tissue without any adverse effects. CONCLUSION Gelatin thrombin granules (FloSeal) are effective in treating severe penetrating rupture of the liver and spleen even during hemorrhagic shock, retransfusion conditions, and coagulation disorder.

The influence of fibrin sealant on demineralized bone matrix-dependent osteoinduction. A quantitative and qualitative study in rats.

Allogeneic demineralized bone matrix (DBM) and bone matrix gelatin (BMG) were implanted with or without fibrin sealant (FS) ectopically (abdominal wall) and orthotopically (7-mm trepanation defect) in 38 male Sprague-Dawley rats. Evaluation was done by descriptive histology, histomorphometry of orthotopic implants, and determination of alkaline phosphatase in ectopic implants. The observation period was 21 days with ectopic implantation and 26 days with orthotopic implantation. In all ectopic specimens, new bone developed without any qualitative difference between specimens with and without FS. The alkaline phosphatase activity did not change significantly upon addition of FS. Morphometry revealed slight differences between the groups with and without FS. The peripheral bone deposits in the BMG + FS group, was significantly larger than in the BMG group. These investigations demonstrated neither a clearly positive nor negative effect of FS on ectopic osteoinduction or BMG-dependent osteoregeneration.