Expansion of inadequate volume of coagulum for pyelolithotomy: an experimental and clinical study

The unit volume (4 to 18 ml.) of cryoprecipitate provided by the blood bank is sometimes inadequate to fill a given pelviocaliceal system. The effect of diluting the cryoprecipitate with urine, saline and water to increase this volume was investigated. Samples of cryoprecipitate were expanded with urine, saline solution and water in proportions of 3:1 and 1:1 at 37C. One part of 10 per cent calcium chloride was added to the various dilutions for each 20 parts of unexpanded cryoprecipitate. All samples resulted in tenacious coagula. The mean generation time of the coagula was 2.25 minutes with water expansion, and 3 to 4.5 minutes when diluted with urine and saline. The mean tensile strength decreased 44 to 64 per cent with water expansion, and 7 to 32 per cent when diluted with urine and saline. Water expansion is not recommended because of the marked decrease in generation time and tensile strength. In patients cryoprecipitate expanded with urine or saline provided tenacious coagula.