Sources of fibrinogen for coagulum pyelolithotomy, without thrombin. A comparative study.

Coagulum pyelolithotomy without the use of thrombin is simplified by using single donor plasma, fresh frozen plasma, and "maxi-cryoprecipitate" (expanded cryoprecipitate) as sources of fibrinogen. The physical properties, including generation time, breaking point, and tensile strength were compared for different coagula. An illustrative case is presented for each fibrinogen source. The tensile strength of fresh frozen plasma coagulum was 15 per cent (17 Gm/cm2) and of maxi-cryoprecipitate 29 to 33 per cent (31-46 Gm/cm2) that of cryoprecipitate, but both were strong enough for clinical use. The preferred source of fibrinogen is cryoprecipitate followed by maxi-cryoprecipitate and fresh frozen plasma in that order. Twenty parts of fibrinogen to one part of 10 per cent calcium chloride provided the shortest generation time and the greatest tensile strength in each of the experiments, and is used exclusively by the authors at present. Single donor plasma is not recommended as a source of fibrinogen for coagulum generation clinically.