This book has been prompted by recent advances in the safe prevention of thromboembolism by subcutaneous heparin prophy- laxis, in particular postoperativt>ly. It has been correctly called by S. Sherry a major breakthrough in medicine. Although thrombo- embolism was first recognized by Laennec in 1819 and defined by Virchow in 1846, its development was not well understood and its prevention escaped our best efforts until now. This all-too-com- mon, sudden, unexpected and unwanted form of morbidity and mortality, always referred to in the surgical patient as postoper- ative pulmonary...