BLOOD AND BLOOD DERIVATIVES — COHN 429 



The fine structure of fibrin film has been shown to involve pores 

 which in one type are of the order of 60 angstrom units in diameter. 

 Hemoglobin molecules in solution pass through these pores readily, 

 but plasma globulins are partially and fibrinogen molecules completely 

 retained. 



The mechanical properties of certain types of fibrin films make them 

 suited for use as dural substitutes and in the prevention of meningo- 

 cerebral adhesions. The duration of their persistence in the body can 

 be adjusted by suitable treatments. They have been used in neuro- 

 surgical operations and appear to be an excellent material for these 

 purposes, patients having been followed for as long as 15 months with- 

 out the appearance of unfavorable sequelae. Other types of fibrin 

 film and of fibrinogen plastics are being tested for other surgical 

 applications. 



For stopping the flow of blood, in surgical procedures, thrombin is 

 the only component of the clotting mechanism which must be supplied. 

 For the most effective use of thrombin in hemostasis, however, it 

 must be applied with a matrix which can hold the thrombin in the 

 bleeding area until clotting is completed. A porous matrix soaked 

 in thrombin solution can accomplish this mechanical result. Fibrin 

 foam is such a matrix formed from human fibrinogen and thrombin. 

 It effectively controls bleeding from oozing surfaces and from veins, 

 even very large ones. Though not recommended for brisk arterial 

 hemorrhage, it has proved very effective in neurosurgery in controlling 

 hemorrhage from the dura, from tumor beds, from dural sinuses, and 

 from large cerebral veins. In general surgery it has been reported 

 effective, in a small number of patients, in controlling hemorrhage 

 from the cut surface of the liver and kidney, in jaundiced patients, 

 in thoracic operations, and in stopping bleeding in hemophilia. 



In the dry state fibrin foam is a porous material composed of strands 

 of fibers separated by air spaces of macroscopic size. It readily ab- 

 sorbs water, saline, or thrombin solution, and can be used in conjunc- 

 tion with a sulfa drug or with penicillin. The physical properties 

 of the foam, as of the film, can be varied by controlling the conditions 

 of manufacture. Since fibrin foam is prepared completely from 

 human proteins and is rapidly absorbed with minimal tissue reaction, 

 it is left in place, thus preventing recurrence of bleeding. It is easily 

 handled in the operating room, and, like serum albumin, is immediately 

 available for use in emergencies. 



The fractionation of plasma, having made available fibrinogen, 

 thrombin, and the fibrinolytic enzyme in physical states such that they 

 can be employed in a wide variety of products, opens a new chapter, 

 not only in the large number of surgical uses which are emerging but 

 also in our fundamental understanding of the relation between the 



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