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Study objectives: To evaluate Vivostat fibrin sealant in the prevention of air leakage after experimental lung resection in pigs. Design: Randomized study. Setting: University laboratory. Methods: Six Landrace pigs were operated on in both lungs through a median sternotomy. Five different resection sites were created in each lung. Intervention: Randomization was performed to either application of Vivostat fibrin sealant (ConvaTec; Skillman NJ) or human albumin 20% (control) at the resection sites. The lung parenchyma was occluded with a soft clamp for either 1, 2, 5, or 10 min in the treatment group and 10 min in the control group. After removal of the clamp, the lung was ventilated with an increasing intrabronchial pressure of 20, 30, and 45 cm H2O for 2 min at each step. Results: At inspiratory pressures of 20 and 30 cm H2O air leaks were found in the control group but not in the Vivostat group (p < 0.001). At an inspiratory pressure of 45 cm H2O, there were two small air leaks in the Vivostat group at each clamping time (four at 5 min), compared with five small and seven large leaks in the control group. Analysis of the data after 10 min of clamping showed that the Vivostat group was superior to the human albumin group (p 5 0.002). Conclusions: This randomized study shows that Vivostat fibrin sealant is effective in preventing air leakage after small lung resections in pigs, even at high inspiratory pressures. (CHEST 2000; 117:1124 ‐1127)

Autologous fibrin glue was prepared in a new way by means of ethanol. From 42 patients 44 mL of blood with a mean plasma fibrinogen concentration of 3.7 mg/mL was drawn. The product of the preparation was a mean of 2.5 mL of fibrinogen concentrate with a concentration of 28 mg/mL. After addition of 0.3 part of thrombin solution containing calcium chloride and aprotinin, an antifibrinolytic agent, the total volume of two-component fibrin glue was 3.3 mL. The preparation was done in a closed system to ensure sterility and com pleted within ninety minutes. Twenty high-porosity double-velour vascular prostheses were sealed with autologous fibrin glue in the laboratory. The pro stheses were tight for blood up to a pressure higher than 300 mmHg, which was comparable to vascular prostheses impregnated with collagen, but to more than twice the pressure of 130 mmHg, where vascular prostheses preclotted with blood started leaking. Autologous fibrin glue imparts a nice white vascular graft with superior handling characteristics, since it is nonsticky compared with blood-clotted grafts and softer and more pliable than the vascular prostheses impregnated with collagen from the manufacturer. In addition autologous fi brin glue has the obvious advantages of safety from transmission of viral dis eases and from immunologic reactions.

A simple method for preparing concentrated fibrinogen for use in a tissue adhesive system is described. Approximately 75% to 80% of the plasma fibrinogen can be separated and concentrated within 45 to 60 minutes from a small blood sample collected from the patient before the operation. Autologous fibrinogen prepared by this method was evaluated in reconstructive microsurgery of the rabbit oviduct.

Fibrin glue was prepared from citrated plasma of human donors by means of ethanol. The outcome was a fibrinogen concentrate with a mean concentration of 43 mg/ml. The fibrinogen was converted to fibrin by the addition of 0.3 part of thrombin solution, 150 NIH U/ml, containing 100 mM calcium chloride. In a rat model full-thickness skin grafts were sealed with the glue, and the adhesive strength was measured at different fibrin concentrations, and after a variable reaction time, and compared to commercial fibrin glue (Tisseel®). The strength of ethanol-prepared glue was directly proportional to the fibrin concentration, and increased rapidly within the first minutes of the reaction time. The strength of the commercial glue could be obtained with autologous fibrin glue at the same fibrin concentration.

The morphology of the healing process of microsurgical reanastomosis of the rabbit oviduct with the use of fibrin adhesive, autologous and heterologous, and conventional sutures is described. Both oviducts in 48 rabbits were cut and reanastomosis were performed. The rabbits were killed at different intervals after the operations, ranging from 2 h to 28 days, and the anastomoses were evaluated by histomorphological examination. The autologous fibrin adhesive was absorbed after a week and an uncomplicated healing was observed. Heterologous fibrin adhesive caused a granulomatous inflammation interpreted as an immune reaction of the host to the foreign protein, and conventional suturing resulted in severe tissue damage with an intensive inflammatory reaction.

A method for preparing concentrated fibrinogen for use in autologous fibrin adhesive is described. The adhesive was used in seven patients with eight chronic leg ulcers. The ulcers were divided into two equal sections, and the adhesive was used to seal split-thickness skin grafts in one section, while no adhesive was used to seal the grafts in the other section of the ulcer. The strength of adhesion was measured 3 1/2 minutes after transplantation of a 1-cm2 test split-thickness skin graft. In the sealed grafts, the breaking strength varied from 12 to 26 gm. In the unsealed transplants, the strength was less than 5 gm. The take of the meshed split-thickness skin grafts was equal in the sealed and the unsealed areas, varying from 90 to 100 percent. Biopsies taken on day 7 showed a splitting between graft and recipient bed in half the unsealed grafts; none of the sealed grafts showed splitting, indicating a more stable graft in the sealed areas. Biopsies taken on day 21 showed no difference between sealed and unsealed grafts.

Autologous fibrin glue was used in 20 patients undergoing lung resection to reduce pulmonary air leaks and improve hemostasis. The fibrinogen in the glue was prepared by ethanol precipitation of plasma separated from 88 ml of the patient's blood. The mean volume of fibrinogen concentrate +/- SD was 4.9 +/- 0.5 ml with a fibrinogen concentration of 28 +/- 5 mg/ml. The yield obtained by the separation was 81% +/- 9%. One part of fibrinogen concentrate was converted to solid fibrin by means of 0.3 parts of thrombin solution. The outcome was 6.4 ml of two-component fibrin glue. The preparation was performed in a closed system to ensure sterility, and was completed within 90 min. Pulmonary air leak decreased following sealing of the resection lines with autologous fibrin glue and the hemostasis was effective. No adverse effects were observed, and all cultures from the glue were negative. Autologous fibrin glue has the obvious advantages of safety from transmission of viral diseases and from immunological reactions. In summary, we report a new technique for preparing autologous fibrin glue with a high concentration of fibrinogen making it a safe and effective sealant of pulmonary air leak and hemostatic agent in thoracic surgery.

To salvage patients' blood and improve hemostasis in cardiac operations, autologous fibrin glue was prepared in a new way by means of ethanol from pericardial blood. The yield from 44 mL of blood was 2.1 ± 0.7 mL (mean ± standard deviation) of fibrinogen concentrate with a concentration of 25.1 ± 7.5 mg/mL; 2.7 mL of two-component glue was obtained after the addition of thrombin solution. The glue has the advantages of safety from transmission of viral diseases and from immunologic reactions.

The two-component tissue adhesive system where the one component is a concentrated human fibrinogen solution and the other component is a thrombin solution containing Ca2+ is becoming increasingly important in surgery. In the commercially available tissue adhesive, the fibrinogen is separated from pooled plasma. The risk of transmitting foreign immunogens and viruses, always present when foreign biological materials are used, will be eliminated if the fibrinogen is separated from the patient's own blood. A method using ethanol precipitation is described for preparing a concentrated fibrinogen solution from plasma separated from small amounts of blood. The method is fast, the final product can be obtained within 30-60 min after collection of the blood. The recovery is compared with the recovery obtained by separating the fibrinogen with ammonium sulfate precipitation and with cryoprecipitation. The method using ethanol is by far the most profitable, and the product is evaluated by experimental liver surgery in pigs.

1. (1) The K + concentration in human blood platelets, separated at room temperature from citrated platelet-rich plasma at pH 7.1, was 88 μmol/10 11 platelets. 2. (2) Changing pH in the plasma altered immediately the intracellular K + concentration in platelets. An equilibrium was reached within 60–90 min and no further change was observed during the next 90 min. The maximum value was found at pH 6.0–6.4. 3. (3) The velocity of passive K + efflux varied with pH, having a minimum value at pH 6.0–6.4. Increasing the pH to 7.9 accelerated the velocity by a factor of 15. This was found in platelets incubated with ouabain to inhibit the active (Na + , K + )-pump.

The hypothesis that the damaging effect on the stomach mucosa of salicylic acid and its derivatives is ascribable to an uncoupling of oxidative phosphorylation has been investigated by testing of mitochondria isolated from the corpus gland area of mini-pig gastric mucosa. Mitochondria, influenced by salicylate or acetylsalicylate (0.7-5.6 mmol/l), demonstrated increased respiration rate, decreased respiratory control ratio, and decreased P/O ratio when tested in vitro. Uncoupling of oxidative phosphorylation occurred at a salicylate concentration between 3.5 and 5.6 mmol/l.

SummaryThe influence of p-CMB, iodoacetamide, iodoacetic acid, N-ethylmaleimide, glycerinederivatives and of EDTA on thrombingeneration on fibrinpolymeriza- tion and on the physical strength of clots as expressed by spectrophotometrical and thrombelastographic measurements respectively has been examined.P-CMB and N-ethylmaleimide significantly inhibit the thrombin generation.EDTA retards the initial steps of the fibrinpolymerization and it increases the final turbidity. Its effect is neutralized by calcium and magnesium. The sulfhydrylinhibitors do not inhibit the polymerization neither do the glycinederivatives.To judge from these results does FSF not influence the polymerization but calcium and magnesium do. This statement is verified using FSF deficient plasma.The four SH-inhibitors tested inhibit the development of a normal thromb- elastogram, specially in reducing the mA values. Cysteine, having no effect by itself, reverses the effect of p-CMB and iodoacetamide.p-CMB has a similar effect when added to FSF deficient plasma and the main effect of this SH inhibition is suggested to be on platelet enzymes. p-CMB and iodoacetic acid also reduce the m A values of platelet-free normal plasma possibly by inhibiting FSF.

A semi-micromethod for testing the aggregability of platelets in whole blood is described. Aggregation is induced with ADP at 37° C in 0,1 ml samples of citrated blood. At 30 seconds intervals aggregation is stopped and the number of nonaggregated platelets are determined.The main results as found in “normal” human donors (having received no drugs) are:1) Platelet aggregation in whole blood is less dependent on the pH, the platelet number, the time elapse from blood sampling to aggregation test as compared with platelet aggregation in plasma (a.m. Born).2) Disaggregation is only observed to a minor degree (after 180 seconds the maximal disaggregation amounts to 30% of the aggregated platelets).3) Secondary aggregation is negligible.The technique is simple and can be used in the clinic without special equipments. The results are discussed.

Oozing of blood from wound tissues after some time of total body perfusion and the demonstration of microemboli have brought into focus the inevitable disappearance of platelets from the blood during extracorporeal circulation. Recirculation experiments using dog blood are reported. The effect of a bubble oxygenator and a membrane oxygenator is compared. It is concluded that in principle they both contribute to the removal of functionally active platelets.

The mucosal content of adenosine triphosphate, adenosine diphosphate and adenosine monophosphate in mini-pig corpus gland area and in pyloric gland area was examined after aspirin ingestion in acute experiments and after ingestion for several weeks. Ingestion of aspirin led to a statistically significant decrease of adenine nucleotide content in corpus gland and in pyloric gland area. An inverse correlation between the pH of the aspirin suspensions and the size of the decrease was established in the short-time experiments. In non-affected pyloric gland area mucosa and adenine nucleotide content was significantly lower than in the corpus gland area. Pyloric mucosa was more susceptible to aspirin-induced lowering of adenine nucleotide content than was the corpus mucosa. Prolonged aspirin ingestion led to statistically significant reductions of adenine nucleotide pool. The findings explain the decrease in mucous secretion and in acid secretion demonstrated in several studies. The finding of lower and more susceptible adenine nucleotide pool in the pyloric area might be the explanation for the preponderant occurrence of aspirin ulcerations in this region.

The aggregability of platelets stored in plasma at room-temperature, pH 7.2–7.4, decreased approximately by a factor ten over a 24 hr period. Storage at pH 6.5 resulted in a more pronounced decrease. In some experiments this was reversible if the platelets were allowed to regenerate by incubation at pH 7.4 one or two hrs before measuring the aggregation. The procedure of concentrating platelets as well as storing the platelets as a concentrate, contributed to a decrease in aggregability. Saline as a medium for storage caused complete loss of aggregability within a few hours. K+, Ca2+ and glucose was shown by dialysis experiments to be vital factors for maintaining platelet aggregability during storage.