vitamin-k-semiquinone-radical and Scoliosis

Protein Z is a vitamin-K-dependent plasma glycoprotein synthesized by the liver, showing great structural similarity to other vitamin-K-dependent coagulation factors such as factors II, IX, X and protein C and S. Protein Z seems to assist haemostasis by binding thrombin and promoting its association with phospholipid surfaces, and it downregulates coagulation by forming a complex with the plasma protein-Z-dependent protease inhibitor, which inhibits activated factor Xa. Studies in patients with a bleeding tendency of unknown origin during and after surgery displayed diminished protein-Z-concentrations in about 50 % of the patients with recurrent bleeding. We report about a 19 year old patient, who suffers from a posttraumatic paraplegia subTh 8 since childhood. In 1998 a correction operation in order to reduce scoliosis with restrictive ventilatory defects had to be stopped before successful spondylodesis because of massive bleeding. After a second intraoperative bleeding incident and exclusion of other more frequent thrombocytic or plasmatic causes of hypocoagulability protein-Z-deficiency finally was diagnosed. Under substitution of protein-Z using PPSB (Beriplex P/N) a repeatedly postponed implantation of a sphincter-externus (Brindley-) stimulator could be performed without bleeding complications in 2001, and this was also true for two other urological interventions in 2002. This report about repeated life-threatening intraoperative bleeding in a patient with protein-Z-deficiency, which could be successfully counteracted using selected plasma concentrates with guaranteed protein-Z-amounts, underlines the importance of protein-Z-assessment in some rare cases of bleeding tendency of "unknown origin" and documents the preventive plasma Protein-Z-levels achieved with the substitution of PPSB.

Topics: Adult; Blood Proteins; Hemorrhage; Humans; Intraoperative Complications; Male; Orthopedic Procedures; Paraplegia; Scoliosis; Vitamin K