To investigate the effectiveness of high-vacuum and passive drainage systems after elective thyroid resection. Prospective randomised clinical study and multicentre postal survey. Military hospital, Germany. 80 patients, treated with passive closed drains (n = 40) or high-vacuum systems (n = 40). 1. Measuring the amount of blood collected during drainage and the extent of residual haematoma on ultrasonography. 2. Survey in Austria, Germany and Switzerland of annual number of bilateral thyroid resections, type of drainage used, and volume of postoperative drainage. 799 of the 1698 hospitals surveyed replied (47.2%). 785 (98.2%) of the 799 surgeons said that they used drainage systems of whom 766 (97.6%) used high-vacuum systems. In the 40 patients in whom passive closed drainage was used, the median volume drained was 34 ml (range 0-175) compared with 115 ml (40-346) in the high vacuum group (p < 0.01). In the passive drainage group the extent of residual haematoma measured by us was 4.4 ml (range 0-21.7) compared with 5.3 ml (0.6-24.9) in the high vacuum group. The high-vacuum drainage that is most commonly used in Austria, Germany, and Switzerland results in increased blood loss with no reduction in the extent of residual wound haematoma and offers no additional advantage over passive drainage systems in thyroid surgery.
