The incidence of postoperative pulmonary perfusion defects.

The incidence of postoperative thromboembolism was studied using radioisotope lung perfusion and ventilation scanning. 26% of patients had defects on their pre-operative scans and 8% developed new unmatched perfusion defects postoperatively, indicating possible pulmonary emboli. This latter figure was much lower than some previously recorded results and was similar in 2 groups of patients--one receiving dextran 70 prophylaxis during operation and the other a control group who received saline.